A UV-resistant and environmentally friendly photovoltaic solar cable, preparation method and application thereof

Abstract

The present invention relates to the field of cable materials, and provides an anti-UV environmentally friendly photovoltaic solar cable, the structure of which includes a cable core, an insulating layer, an insulating layer, a shielding layer and an outer layer. The outer layer is prepared from a modified polyurethane and polyester composite material, and is obtained by a melt extrusion process using components such as surface-modified titanium dioxide / magnesium hydroxide filler, montmorillonite, thermoplastic polyurethane and modified polyester masterbatch. The cable has excellent flame retardancy, UV resistance and durability, can maintain stable performance under adverse climatic conditions, and meets the special needs of solar power stations, rooftop solar panel systems and photovoltaic agricultural facilities. The preparation method includes the step-by-step preparation of a cable core, an insulating layer, an insulating layer, a shielding layer and an outer layer, and finally the outer layer is coated by twin-screw extrusion to ensure that the cable is safe, environmentally friendly and durable.

Description

Technical Field

[0001] The invention relates to the field of cable materials, and in particular to an anti-UV and environment-friendly photovoltaic solar cable. Background Art

[0002] Based on the long-term application needs of photovoltaic solar cables in harsh outdoor environments, it is particularly important to ensure that their insulation materials have excellent flame retardant and UV resistance. Since photovoltaic cables need to be exposed to strong sunlight for a long time, UV radiation will accelerate the aging of the insulation layer, resulting in the degradation of its mechanical and electrical properties, thereby shortening the service life of the cable. Therefore, the insulation material must have excellent UV resistance to extend its outdoor service life and ensure the stable operation of the photovoltaic system. In addition, photovoltaic cables are often laid in buildings, factories and other flammable environments. Once the cable fails, the risk of fire is extremely high, and flame retardancy becomes a key indicator to ensure the safe operation of the system. Therefore, the insulation material needs to have efficient flame retardant properties, which can quickly suppress the fire near the fire source and reduce the risk of fire spread. Meeting the two major performance requirements of flame retardancy and UV resistance can not only significantly improve the comprehensive performance of photovoltaic cables, but also broaden their application scope, especially in complex and changeable outdoor environments, which will greatly promote the technological progress of the photovoltaic industry and promote the promotion and popularization of green energy.

[0003] However, the existing material technology still has great deficiencies in flame retardancy and anti-ultraviolet performance. For example, the Chinese patent with publication number CN102254597A discloses a photovoltaic cable and its manufacturing method, but it lacks anti-ultraviolet design, has poor weather resistance under long-term ultraviolet radiation, and is prone to aging and cracking problems, which affects the service life of the cable. In addition, the existing flame retardant additives often cause the mechanical properties of the material to decline, and it is impossible to maintain the strength and flexibility of the material while ensuring the flame retardant effect. These deficiencies are mainly due to the fact that the molecular structure design of the material and the selection of the flame retardant additive are not optimized enough, and it is impossible to effectively take into account UV stability and flame retardant effect, resulting in the material often sacrificing other properties when meeting a certain performance requirement. Therefore, the development of a new insulating material that can balance flame retardancy, anti-ultraviolet ability and mechanical properties has become a technical problem that needs to be solved urgently in the current photovoltaic cable industry. Summary of the invention

[0004] (1) Technical issues solved

[0005] The purpose of the present invention is to provide a UV-resistant and environmentally friendly photovoltaic solar cable with excellent flame retardancy, UV resistance, environmental protection and durability, which is used to meet the special needs of solar power stations, rooftop solar panel systems and photovoltaic agricultural facilities exposed to outdoor environments for a long time.

[0006] (2) Technical solution

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] An anti-UV environmentally friendly photovoltaic solar cable, which comprises a cable core, an isolation layer, an insulating layer, a shielding layer and an outer layer from the inside to the outside;

[0009] The outer layer is a modified flame-retardant two-component polyurethane and polyester composite insulation material, which is prepared by mixing 50-70 parts of modified polyurethane masterbatch, 30-50 parts of modified polyester masterbatch, 0.1-0.5 parts of antioxidant and 0.1-0.5 parts of zinc stearate uniformly and then melt extruding;

[0010] The antioxidant is Irganox 1010 antioxidant;

[0011] The modified polyurethane masterbatch is obtained by melt extrusion granulation of surface-modified titanium dioxide / magnesium hydroxide filler, montmorillonite, thermoplastic polyurethane and zinc stearate;

[0012] The surface-modified titanium dioxide / magnesium hydroxide filler is obtained by surface-modifying the titanium dioxide / magnesium hydroxide filler with γ-aminopropyltriethoxysilane;

[0013] The modified polyester masterbatch is prepared by copolymerization of benzimidazole monomer, polyethylene glycol, tetrabutyl titanate and terephthalic acid, and then obtained by drying and pelletizing.

[0014] Furthermore, the preparation method of the modified polyurethane masterbatch is as follows: by weight, 2.5 to 6.5 parts of surface modified titanium dioxide / magnesium hydroxide filler, 1.5 to 3.5 parts of montmorillonite, 30 to 65 parts of thermoplastic polyurethane and 0.5 to 1.5 parts of zinc stearate are added to a mixer, mixed at a speed of 1000 to 1500 rpm for 5 to 10 minutes, and then added to a twin-screw extruder, the extrusion temperature is set to 180 to 200°C, the screw speed is 100 to 200 rpm, and then extruded and formed, and finally granulated to obtain the modified polyurethane masterbatch.

[0015] Further, the preparation method of the surface modified titanium dioxide / magnesium hydroxide filler is as follows: after mixing 1.0-3.5 parts of γ-aminopropyltriethoxysilane and 30 parts of ethanol in parts by weight, 100 parts of deionized water are added dropwise, and after the addition is completed, 8-16 parts of titanium dioxide / magnesium hydroxide filler are added, followed by stirring and heating to 50-80° C. for 60-120 min. After the stirring is completed, the mixed solution is filtered to retain the filter residue, and then the filter residue is washed once with deionized water, and finally the filter residue is completely vacuum dried at room temperature to obtain the surface modified titanium dioxide / magnesium hydroxide filler;

[0016] Furthermore, the titanium dioxide / magnesium hydroxide filler is composed of magnesium hydroxide micron particles and titanium dioxide nanowires uniformly distributed on the surface thereof.

[0017] Furthermore, the titanium dioxide nanowires are in-situ grown and evenly distributed on the surface of the magnesium hydroxide micron particles in a divergent manner.

[0018] Furthermore, the average diameter of the titanium dioxide nanowires is 30-90 nm, and the average length is 200-650 nm.

[0019] Furthermore, the mass ratio of the magnesium hydroxide microparticles to the titanium dioxide nanowires is (75-90)%:(10-25)%.

[0020] Furthermore, the preparation method of the titanium dioxide / magnesium hydroxide filler is as follows: by weight, 20 to 35 parts of magnesium hydroxide micron particles, 2.0 to 5.0 parts of tetraisopropyl titanate and 100 parts of ethanol are mixed evenly and added into a reaction kettle, and then heated to 250 to 280° C., kept warm for 240 to 360 minutes for hydrothermal reaction, and then cooled to room temperature, the hydrothermal reaction solution is filtered to retain the filter residue, and then the filter residue is washed with ethanol for 3 times, and finally vacuum dried at room temperature to completely obtain the titanium dioxide / magnesium hydroxide filler.

[0021] The present invention adopts surface-modified titanium dioxide / magnesium hydroxide filler in modified polyurethane masterbatch, and is mainly designed to enhance the flame retardancy, mechanical strength and anti-ultraviolet performance of the cable. After the titanium dioxide / magnesium hydroxide filler is surface-modified by γ-aminopropyltriethoxysilane, its compatibility with the polyurethane matrix can be significantly improved, so that it forms a more uniform dispersion in the material system, ensuring that it does not affect the mechanical properties of the cable while improving the flame retardancy. The surface modification process forms a strong interface interaction between the titanium dioxide and magnesium hydroxide fillers and the polymer matrix by chemical bonding, further improving the reinforcing effect of the filler on the matrix. In the present invention, titanium dioxide is used as a nanofiller and has excellent anti-ultraviolet ability. Its nanowire structure has a large specific surface area, and is uniformly distributed on the surface of magnesium hydroxide micron particles by in-situ growth. The nanowires of this divergent structure can effectively absorb and scatter ultraviolet rays and enhance the weather resistance of the material. The composite filler of titanium dioxide nanowires and magnesium hydroxide micron particles not only gives the material excellent anti-ultraviolet performance, but also further improves the flame retardant performance of the material through the flame retardant properties of magnesium hydroxide. As an inorganic flame retardant, magnesium hydroxide releases moisture at high temperature, dilutes the combustible gas generated during the combustion process, absorbs heat, delays the thermal decomposition of the material, and effectively improves the flame retardant grade of the material. In addition, the introduction of montmorillonite further enhances the flame retardancy and mechanical strength of the material. As a layered silicate, montmorillonite can form a physical barrier in the material, delay the transfer of heat and oxygen, thereby improving the flame retardancy of the material. At the same time, the layered structure of montmorillonite plays a reinforcing role in the polyurethane matrix, further improving the mechanical properties of the material. Montmorillonite and the surface-modified titanium dioxide / magnesium hydroxide filler work synergistically, so that the material has higher impact resistance and tensile resistance while maintaining excellent flame retardancy. Zinc stearate is used as a lubricant and stabilizer in the present invention, which can effectively improve the processing performance of the material, reduce the friction during the melt extrusion process, thereby improving the processing efficiency and surface smoothness of the material.

[0022] Furthermore, the thermoplastic polyurethane is composed of polyester thermoplastic polyurethane and polyether thermoplastic polyurethane in a mass ratio of 3:1.

[0023] The present invention further optimizes the performance of the material by combining polyester thermoplastic polyurethane and polyether thermoplastic polyurethane in a mass ratio of 3:1, thereby achieving synergistic enhancement of the performance of the two. Polyester thermoplastic polyurethane has excellent mechanical strength and heat resistance, and can improve the wear resistance and tensile strength of the material; while polyether thermoplastic polyurethane has better flexibility and hydrolysis resistance, and effectively improves the stability of the material in a humid environment. The reasonable ratio of the two not only improves the overall weather resistance and mechanical properties of the material, but also ensures its durability and environmental adaptability in practical applications.

[0024] Furthermore, the preparation method of the modified polyester masterbatch is as follows: by weight, 60 to 80 parts of terephthalic acid, 40 to 55 parts of polyethylene glycol and 10 to 18 parts of benzimidazole monomer are added to a reaction kettle, heated to 170 to 185° C. under a nitrogen atmosphere, then 0.02 to 0.08 parts of tetrabutyl titanate are added, and the mixture is heated to 220 to 240° C., and the copolymerization reaction is carried out at a stirring speed of 60 to 100 rpm and a stirring time of 60 to 120 min. After the reaction is completed, the mixture is cooled to room temperature and dried, and then granulated to obtain the modified polyester masterbatch.

[0025] Furthermore, the preparation method of the benzimidazole monomer is as follows: at room temperature, by weight, 30 to 45 parts of sodium pyrosulfite, 28 to 35 parts of methyl p-formylbenzoate, and 30 to 38 parts of 3,4-diaminobenzoic acid are added to 300 parts of N,N-dimethylformamide and mixed evenly, the solution is heated to 120 to 140°C, stirred for 240 to 480 minutes, and after stirring completely, poured into 500 parts of -5 to 0°C ice-water mixture, and then the upper suspension of the ice-water mixture is taken into a beaker, stirred at room temperature for 30 to 60 minutes, and then the suspension is filtered to remove the yellow precipitate, and then washed with deionized water 3 times, and finally vacuum dried at room temperature to obtain the benzimidazole monomer.

[0026] The present invention adopts the design of modified polyurethane masterbatch mainly for enhancing the flame retardancy, mechanical strength and durability of the cable. First, the carbonization ability of the benzimidazole monomer forms a protective layer under high temperature environment, giving the copolyester excellent fire safety and anti-dripping performance, effectively reducing the molten drop phenomenon in the fire, and improving the safety performance of the cable. Secondly, the benzimidazole monomer and the polyester matrix formed by copolymerization of terephthalic acid and polyethylene glycol further form a stable physical cross-linking network through hydrogen bonding and π-π stacking interaction, which significantly improves the mechanical properties and durability of the material. This physical cross-linking network enhances the interaction between polymer chains, so that the material exhibits more excellent strength and stability under high temperature and mechanical stress. At the same time, the synergistic effect of the carbonization ability and the physical cross-linking structure not only improves the thermal stability of the material, but also enhances its processing performance, so that the modified polyester masterbatch can maintain good fluidity and processability in a complex processing environment, ensuring that the overall performance of the cable outer layer material is excellent and long-term reliable.

[0027] Further, the cable core comprises a plurality of conductors; each conductor is formed by twisting a plurality of tinned copper monofilaments; the diameter of the tinned copper monofilaments is 0.15~0.32mm;

[0028] Furthermore, the insulating layer is a glass fiber tape; the thickness of the glass fiber tape is 0.1-0.25 mm;

[0029] Furthermore, the insulating layer is cross-linked polyethylene; the thickness of the insulating layer is 1.0-2.5 mm;

[0030] Furthermore, the shielding layer is a shielding layer woven of copper wires, the diameter of the copper wires is 0.12-0.20 mm, and the braiding density is 85-95%;

[0031] The present invention also provides a method for preparing an anti-UV environmentally friendly photovoltaic solar cable, comprising the following steps:

[0032] S1: preparing a cable core: twisting a plurality of tinned copper monofilaments to form a conductor, and then twisting the plurality of conductors to form a cable core;

[0033] S2: preparing an insulating layer: winding a glass fiber tape around the outside of the cable core to form an insulating layer;

[0034] S3: preparing an insulating layer: coating the insulating layer with a layer of cross-linked polyethylene as an insulating layer by an extrusion process;

[0035] S4: preparing a shielding layer: weaving a shielding layer by copper wire on the outside of the insulating layer;

[0036] S5: Preparation of outer layer: Add modified polyurethane masterbatch, modified polyester masterbatch, Irganox 1010 antioxidant and zinc stearate into a mixer, mix at a speed of 30-60 rpm for 10-15 min, then add into a twin-screw extruder, set the extrusion temperature to 180-220°C, the screw speed to 100-200 rpm, and then extrude an outer layer on the outside of the shielding layer.

[0037] The present invention also provides an application of an anti-UV environmentally friendly photovoltaic solar cable in solar power stations, rooftop solar panel systems, and photovoltaic agricultural facilities.

[0038] The purpose of the present invention is to provide a photovoltaic solar cable with excellent flame retardancy, UV resistance, environmental protection and durability, which is used to meet the special needs of solar power stations, rooftop solar panel systems and photovoltaic agricultural facilities exposed to outdoor environments for a long time. To achieve this goal, the present invention designs a new type of cable based on modified flame retardant two-component polyurethane and polyester composite insulation. By reasonably selecting and combining materials, the cable can maintain stable performance under adverse climatic conditions such as high temperature, UV radiation, and humidity changes. Specifically, the cable uses a conductor composed of tinned copper monofilaments to enhance its electrical conductivity and antioxidant ability; a glass fiber tape is used as an insulating layer to provide good mechanical strength and heat resistance; the insulating layer uses cross-linked polyethylene to ensure electrical insulation stability; the shielding layer is woven with copper wire to provide electromagnetic shielding and anti-interference capabilities. Finally, by coating the outer sheath made of modified polyurethane and polyester composite materials on the outer layer, not only is the cable given excellent weather resistance, UV resistance and flame retardancy, but also its environmental protection characteristics are improved, ensuring the safe, stable and sustainable application of the cable in the photovoltaic system.

[0039] (3) Beneficial technical effects

[0040] 1. The present invention adopts surface-modified titanium dioxide / magnesium hydroxide filler, which works synergistically with montmorillonite, zinc stearate and other components to significantly improve the flame retardancy, mechanical strength and UV resistance of the cable. The combination of the UV resistance of titanium dioxide and the flame retardant effect of magnesium hydroxide enables the material to have excellent flame retardancy at high temperatures and remain stable under long-term UV radiation; the layered structure of montmorillonite further enhances the flame retardancy and mechanical properties, ensuring the stability of the material in a high-stress environment. Zinc stearate improves processing performance, production efficiency and product quality. On the whole, the synergistic effect of each component realizes the optimization of multiple properties, solves the problems of aging and poor flame retardancy of existing photovoltaic cables in outdoor use, and has broad application prospects.

[0041] 2. The present invention significantly improves the flame retardancy, mechanical strength and durability of the cable by adopting modified polyurethane masterbatch. Compared with the prior art, the present invention introduces benzimidazole monomer, whose carbonization ability forms a protective layer at high temperature, reduces the molten drop phenomenon in the fire, and improves the fire safety. At the same time, benzimidazole and the polyester matrix interact through hydrogen bonds and π-π stacking to form a more stable physical cross-linking network, which enhances the mechanical properties and durability of the material, so that it maintains better strength and stability under high temperature and mechanical stress. The synergistic effect of each component ensures the thermal stability and processing performance of the material, and optimizes the fluidity and processability of the material in a complex processing environment. On the whole, the present invention not only achieves the improvement of flame retardant performance, but also enhances the safety and service life of the cable. It is particularly suitable for cable applications that need to be exposed to harsh environments for a long time, and has broad market prospects.

[0042] 3. The present invention provides a photovoltaic solar cable with excellent flame retardancy, UV resistance, environmental protection and durability, which is designed for long-term outdoor use. Through the reasonable combination of modified flame-retardant two-component polyurethane and polyester composite insulation materials, the cable maintains stable performance in harsh environments such as high temperature, UV and humidity. Tinned copper monofilaments are used to improve conductivity and oxidation resistance, glass fiber tapes are used to enhance mechanical strength and heat resistance, cross-linked polyethylene ensures electrical insulation, and copper wire braided shielding layers provide good electromagnetic shielding and anti-interference effects. The outer sheath gives the cable excellent weather resistance, flame retardancy and environmental protection, ensuring its safety, stability and long service life in photovoltaic systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a schematic diagram of the front cross-sectional structure of the cable of the present invention.

[0044] Figure 2 This is a SEM morphology of the magnesium hydroxide microparticles used to prepare the outer layer of the cable in Example 1 of the present invention.

[0045] Figure 3 This is the XRD phase diagram of the magnesium hydroxide micron particles used to prepare the outer layer of the cable in Example 1 of the present invention.

[0046] Figure 4 This is a SEM morphology image of the titanium dioxide / magnesium hydroxide filler used to prepare the outer layer of the cable in Example 1 of the present invention.

[0047] Figure 5 This is the XRD phase diagram of the titanium dioxide / magnesium hydroxide filler used to prepare the outer layer of the cable in Example 1 of the present invention.

[0048] The markings of the components in the accompanying drawings are as follows: 11. tinned copper monofilament; 1. cable core; 2. insulation layer; 3. insulating layer; 4. shielding layer; 5. outer layer. DETAILED DESCRIPTION

[0049] To make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0050] In the case of not specifying specific conditions, the operation in the embodiment is carried out according to conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used, if the manufacturer is not indicated, are all common products on the market. The parts not mentioned in the technical content of the present invention will be processed with reference to the prior art. Unless otherwise specified, the following examples and comparative examples will be tested in parallel and use the same processing steps and parameters. Table 1 shows the reagents required for the examples and comparative examples and the corresponding purchasing companies.

[0051] Table 1 Reagents required for the examples and comparative examples and the corresponding purchasing companies

[0052]

[0053] Example 1

[0054] See also Figure 1 , an anti-UV environmentally friendly photovoltaic solar cable, which comprises, from inside to outside, a cable core 1, an isolation layer 2, an insulating layer 3, a shielding layer 4 and an outer layer 5.

[0055] The outer layer 5 of this embodiment is a modified flame-retardant two-component polyurethane and polyester composite insulation material, which is prepared by melt extrusion after uniformly mixing 50 parts of modified polyurethane masterbatch, 30 parts of modified polyester masterbatch, 0.1 parts of Irganox 1010 antioxidant and 0.1 parts of zinc stearate.

[0056] The modified polyurethane masterbatch of this embodiment is obtained by melt extrusion granulation of surface-modified titanium dioxide / magnesium hydroxide filler, montmorillonite, thermoplastic polyurethane and zinc stearate; the surface-modified titanium dioxide / magnesium hydroxide filler is obtained by surface modification of titanium dioxide / magnesium hydroxide filler with γ-aminopropyltriethoxysilane; the modified polyester masterbatch is prepared by copolymerization of benzimidazole monomer, polyethylene glycol, tetrabutyl titanate and terephthalic acid, and then obtained by drying and pelletizing.

[0057] The preparation method of the modified polyurethane masterbatch of the present embodiment is as follows: by weight, 2.5 parts of surface modified titanium dioxide / magnesium hydroxide filler, 1.5 parts of montmorillonite, 30 parts of thermoplastic polyurethane and 0.5 parts of zinc stearate are added to a mixer, mixed at a speed of 1000 rpm for 5 minutes, and then added to a twin-screw extruder, the extrusion temperature is set to 180°C, the screw speed is set to 100 rpm, and then extruded and formed, and finally granulated to obtain the modified polyurethane masterbatch. The preparation method of the surface modified titanium dioxide / magnesium hydroxide filler is as follows: by weight, 1.0 parts of γ-aminopropyltriethoxysilane and 30 parts of ethanol are mixed evenly, and then 100 parts of deionized water are added drop by drop, and after the addition is completed, 8 parts of titanium dioxide / magnesium hydroxide filler are added, and then stirred and heated to 50°C for 60 minutes. After the stirring is completed, the mixed solution is filtered to retain the filter residue, and then the filter residue is washed once with deionized water, and finally the filter residue is completely vacuum dried at room temperature to obtain the surface modified titanium dioxide / magnesium hydroxide filler; the preparation method of the titanium dioxide / magnesium hydroxide filler is as follows: by weight, 20 parts of magnesium hydroxide micron particles, 2.0 parts of tetraisopropyl titanate and 100 parts of ethanol are mixed evenly and added to a reactor, and then heated to 250°C, kept warm for 240 minutes for hydrothermal reaction, and then cooled to room temperature, the hydrothermal reaction solution is filtered to retain the filter residue, and then the filter residue is washed 3 times with ethanol, and finally vacuum dried at room temperature to completely obtain the titanium dioxide / magnesium hydroxide filler.

[0058] The titanium dioxide / magnesium hydroxide filler of this embodiment is composed of magnesium hydroxide micron particles and titanium dioxide nanowires uniformly distributed on the surface thereof. The titanium dioxide nanowires are in-situ grown and evenly distributed on the surface of the magnesium hydroxide micron particles in a divergent shape. The average diameter of the titanium dioxide nanowires is 30nm and the average length is 200nm. The mass ratio of magnesium hydroxide micron particles to titanium dioxide nanowires is 75%:25%.

[0059] The thermoplastic polyurethane of this embodiment is composed of polyester thermoplastic polyurethane and polyether thermoplastic polyurethane in a mass ratio of 3:1.

[0060] The preparation method of the modified polyester masterbatch of the present embodiment is as follows: by weight, 60 parts of terephthalic acid, 40 parts of polyethylene glycol and 10 parts of benzimidazole monomers are added into a reaction kettle, heated to 170°C under a nitrogen atmosphere, then 0.02 parts of tetrabutyl titanate are added, and the mixture is heated to 220°C, and the copolymerization reaction is carried out at a stirring speed of 60 rpm and a stirring time of 60 min. After the reaction is completed, the mixture is cooled to room temperature and dried, and then granulated to obtain the modified polyester masterbatch. The preparation method of the benzimidazole monomer is as follows: at room temperature, by weight, 30 parts of sodium pyrosulfite, 28 parts of methyl p-formylbenzoate, and 30 parts of 3,4-diaminobenzoic acid are added to 300 parts of N,N-dimethylformamide and mixed evenly, the solution is heated to 120°C, stirred for 240 minutes, and after stirring completely, poured into 500 parts of -5°C ice-water mixture, and then the upper suspension of the ice-water mixture is taken into a beaker, stirred at room temperature for 30 minutes, and then the suspension is filtered to remove the yellow precipitate, and then washed with deionized water 3 times, and finally vacuum dried at room temperature to obtain the benzimidazole monomer.

[0061] The cable core 1 of this embodiment includes multiple conductors; each conductor is twisted from multiple tinned copper monofilaments; the diameter of the tinned copper monofilaments is 0.15mm; the insulating layer 2 is a glass fiber tape; the thickness of the glass fiber tape is 0.1mm; the insulating layer 3 is cross-linked polyethylene; the thickness of the insulating layer 3 is 1.0mm; the shielding layer 4 is a shielding layer 4 woven from copper wires, the diameter of the copper wires is 0.12mm, and the braiding density is 85%.

[0062] The present invention also provides a method for preparing an anti-UV environmentally friendly photovoltaic solar cable, comprising the following steps:

[0063] S1: using a plurality of tinned copper monofilaments twisted to form a conductor, and then the plurality of conductors twisted to form a cable core 1;

[0064] S2: Winding the glass fiber tape around the outside of the cable core 1 to form an insulation layer 2;

[0065] S3: coating the insulating layer 2 with a layer of cross-linked polyethylene as the insulating layer 3 by an extrusion process;

[0066] S4: a shielding layer 4 is woven by copper wire outside the insulating layer 3;

[0067] S5: Add modified polyurethane masterbatch, modified polyester masterbatch, Irganox 1010 antioxidant and zinc stearate into a mixer, mix at a speed of 30 rpm for 10 min, then add into a twin-screw extruder, set the extrusion temperature to 180°C, the screw speed to 100 rpm, and then extrude an outer layer 5 on the outside of the shielding layer 4.

[0068] according to Figures 1 to 5The analysis results show that: Figure 1 The schematic diagram of the front cross-sectional structure of the cable of the present invention is shown. The cable includes a cable core, an isolation layer, an insulating layer, a shielding layer and an outer layer from the inside to the outside, and the structural arrangement of each layer is clearly shown. Figure 2 This is a SEM morphology image of the magnesium hydroxide micron particles used in the cable outer layer in Example 1 of the present invention, which proves that the magnesium hydroxide micron particles have good morphology and crystal structure, showing uniform particle distribution and clear microscopic morphology. Figure 3 This is the XRD phase diagram of magnesium hydroxide microparticles, which further verifies the stability of its crystal structure. Figure 4 The SEM morphology of the titanium dioxide / magnesium hydroxide filler is shown, indicating that the titanium dioxide nanowires grow uniformly in situ and are diffusely distributed on the surface of the magnesium hydroxide micron particles, forming a unique structure of the titanium dioxide / magnesium hydroxide composite filler, ensuring the effective bonding and distribution of the filler. Figure 5 The XRD phase diagram of titanium dioxide / magnesium hydroxide filler further proves the formation and stability of its crystal phase structure. In summary, the present invention successfully prepares titanium dioxide / magnesium hydroxide composite fillers with good morphology, stable crystal phase structure and uniform growth of titanium dioxide nanowires through a specific preparation method. These fillers are evenly distributed in the outer layer of the cable, which can effectively improve the overall performance of the cable.

[0069] Example 2

[0070] A UV-resistant and environment-friendly photovoltaic solar cable comprises, from inside to outside, a cable core 1, an insulating layer 2, an insulating layer 3, a shielding layer 4 and an outer layer 5.

[0071] The outer layer 5 of this embodiment is a modified flame-retardant two-component polyurethane and polyester composite insulation material, which is prepared by melt extrusion after uniformly mixing 56 parts of modified polyurethane masterbatch, 36 parts of modified polyester masterbatch, 0.2 parts of Irganox 1010 antioxidant and 0.2 parts of zinc stearate.

[0072] The modified polyurethane masterbatch of this embodiment is obtained by melt extrusion granulation of surface-modified titanium dioxide / magnesium hydroxide filler, montmorillonite, thermoplastic polyurethane and zinc stearate; the surface-modified titanium dioxide / magnesium hydroxide filler is obtained by surface modification of titanium dioxide / magnesium hydroxide filler with γ-aminopropyltriethoxysilane; the modified polyester masterbatch is prepared by copolymerization of benzimidazole monomer, polyethylene glycol, tetrabutyl titanate and terephthalic acid, and then obtained by drying and pelletizing.

[0073] The preparation method of the modified polyurethane masterbatch of this embodiment is as follows: by weight, 4 parts of surface modified titanium dioxide / magnesium hydroxide filler, 2.1 parts of montmorillonite, 44 parts of thermoplastic polyurethane and 0.8 parts of zinc stearate are added to a mixer, mixed at a speed of 1150 rpm for 7 minutes, and then added to a twin-screw extruder, the extrusion temperature is set to 186°C, the screw speed is set to 130 rpm, and then extruded and formed, and finally granulated to obtain the modified polyurethane masterbatch. The preparation method of the surface modified titanium dioxide / magnesium hydroxide filler is as follows: by weight, 1.8 parts of γ-aminopropyltriethoxysilane and 30 parts of ethanol are mixed evenly, and then 100 parts of deionized water are added drop by drop, and after the addition is completed, 10 parts of titanium dioxide / magnesium hydroxide filler are added, and then stirred and heated to 60°C for 84 minutes. After the stirring is completed, the mixed solution is filtered to retain the filter residue, and then the filter residue is washed once with deionized water, and finally the filter residue is completely vacuum dried at room temperature to obtain the surface modified titanium dioxide / magnesium hydroxide filler; the preparation method of the titanium dioxide / magnesium hydroxide filler is as follows: by weight, 24 parts of magnesium hydroxide micron particles, 3.6 parts of tetraisopropyl titanate and 100 parts of ethanol are mixed evenly and added to a reactor, and then heated to 260°C, kept warm for 276 minutes for hydrothermal reaction, and then cooled to room temperature, the hydrothermal reaction solution is filtered to retain the filter residue, and then the filter residue is washed 3 times with ethanol, and finally vacuum dried at room temperature to obtain the titanium dioxide / magnesium hydroxide filler.

[0074] The titanium dioxide / magnesium hydroxide filler of this embodiment is composed of magnesium hydroxide micron particles and titanium dioxide nanowires uniformly distributed on the surface thereof. The titanium dioxide nanowires are in-situ grown and evenly distributed on the surface of the magnesium hydroxide micron particles in a divergent shape. The average diameter of the titanium dioxide nanowires is 42nm and the average length is 305nm. The mass ratio of magnesium hydroxide micron particles to titanium dioxide nanowires is 81%:19%.

[0075] The thermoplastic polyurethane of this embodiment is composed of polyester thermoplastic polyurethane and polyether thermoplastic polyurethane in a mass ratio of 3:1.

[0076] The preparation method of the modified polyester masterbatch of the present embodiment is as follows: by weight, 66 parts of terephthalic acid, 44 parts of polyethylene glycol and 13 parts of benzimidazole monomers are added into a reaction kettle, heated to 177°C under a nitrogen atmosphere, then 0.04 parts of tetrabutyl titanate are added, and the mixture is heated to 228°C, and the copolymerization reaction is carried out at a stirring speed of 77 rpm and a stirring time of 84 min. After the reaction is completed, the mixture is cooled to room temperature and dried, and then granulated to obtain the modified polyester masterbatch. The preparation method of the benzimidazole monomer is as follows: at room temperature, by weight, 30 parts of sodium pyrosulfite, 28 parts of methyl p-formylbenzoate, and 30 parts of 3,4-diaminobenzoic acid are added to 300 parts of N,N-dimethylformamide and mixed evenly, the solution is heated to 120°C, stirred for 240 minutes, and after stirring completely, poured into 500 parts of -4°C ice-water mixture, and then the upper suspension of the ice-water mixture is taken into a beaker, stirred at room temperature for 30 minutes, and then the suspension is filtered to remove the yellow precipitate, and then washed with deionized water 3 times, and finally vacuum dried at room temperature to obtain the benzimidazole monomer.

[0077] The cable core 1 of this embodiment includes a plurality of conductors; each conductor is twisted by a plurality of tinned copper monofilaments; the diameter of the tinned copper monofilaments is 0.19 mm; the insulating layer 2 is a glass fiber tape; the thickness of the glass fiber tape is 0.17 mm; the insulating layer 3 is cross-linked polyethylene; the thickness of the insulating layer 3 is 1.45 mm; the shielding layer 4 is a shielding layer 4 woven of copper wires, the diameter of the copper wires is 0.14 mm, and the braiding density is 88%;

[0078] The present invention also provides a method for preparing an anti-UV environmentally friendly photovoltaic solar cable, comprising the following steps:

[0079] S1: using a plurality of tinned copper monofilaments twisted to form a conductor, and then the plurality of conductors twisted to form a cable core 1;

[0080] S2: Winding the glass fiber tape around the outside of the cable core 1 to form an insulation layer 2;

[0081] S3: coating the insulating layer 2 with a layer of cross-linked polyethylene as the insulating layer 3 by an extrusion process;

[0082] S4: a shielding layer 4 is woven by copper wire outside the insulating layer 3;

[0083] S5: Add modified polyurethane masterbatch, modified polyester masterbatch, Irganox 1010 antioxidant and zinc stearate into a mixer, mix at a speed of 32 rpm for 12 min, then add into a twin-screw extruder, set the extrusion temperature to 184°C, the screw speed to 122 rpm, and then extrude an outer layer 5 around the outside of the shielding layer 4.

[0084] Example 3

[0085] A UV-resistant and environment-friendly photovoltaic solar cable, which comprises, from inside to outside, a cable core 1, an insulating layer 2, an insulating layer 3, a shielding layer 4 and an outer layer 5;

[0086] The outer layer 5 of this embodiment is a modified flame-retardant two-component polyurethane and polyester composite insulation material, which is prepared by mixing 62 parts of modified polyurethane masterbatch, 42 parts of modified polyester masterbatch, 0.3 parts of Irganox 1010 antioxidant and 0.3 parts of zinc stearate uniformly and then melt extruding;

[0087] The modified polyurethane masterbatch of this embodiment is obtained by melt extrusion granulation of surface-modified titanium dioxide / magnesium hydroxide filler, montmorillonite, thermoplastic polyurethane and zinc stearate; the surface-modified titanium dioxide / magnesium hydroxide filler is obtained by surface modification of titanium dioxide / magnesium hydroxide filler with γ-aminopropyltriethoxysilane; the modified polyester masterbatch is prepared by copolymerization of benzimidazole monomer, polyethylene glycol, tetrabutyl titanate and terephthalic acid, and then obtained by drying and pelletizing.

[0088] The preparation method of the modified polyurethane masterbatch of the present embodiment is as follows: by weight, 5 parts of surface modified titanium dioxide / magnesium hydroxide filler, 2.7 parts of montmorillonite, 53 parts of thermoplastic polyurethane and 1.1 parts of zinc stearate are added to a mixer, mixed at a speed of 1300 rpm for 7 minutes, and then added to a twin-screw extruder, the extrusion temperature is set to 190°C, the screw speed is 150 rpm, and then extrusion molding is performed, and finally granulation is performed to obtain the modified polyurethane masterbatch. The preparation method of the surface modified titanium dioxide / magnesium hydroxide filler is as follows: after mixing 2.4 parts of γ-aminopropyltriethoxysilane and 30 parts of ethanol by weight, 100 parts of deionized water are added drop by drop, and 13 parts of titanium dioxide / magnesium hydroxide filler are added after the addition is completed, and then the mixture is stirred and heated to 65°C for 95 minutes. After the stirring is completed, the mixed solution is filtered to retain the filter residue, and then the filter residue is washed once with deionized water, and finally the filter residue is completely vacuum dried at room temperature to obtain the surface modified titanium dioxide / magnesium hydroxide filler; The preparation method of the titanium dioxide / magnesium hydroxide filler is as follows: after mixing 29 parts of magnesium hydroxide micron particles, 4.2 parts of tetraisopropyl titanate and 100 parts of ethanol by weight, the mixture is added to a reactor, and then heated to 265°C, kept warm for 300 minutes for hydrothermal reaction, and then the hydrothermal reaction solution is filtered to retain the filter residue after cooling to room temperature, and then the filter residue is washed 3 times with ethanol, and finally the titanium dioxide / magnesium hydroxide filler is completely vacuum dried at room temperature.

[0089] The titanium dioxide / magnesium hydroxide filler of this embodiment is composed of magnesium hydroxide micron particles and titanium dioxide nanowires uniformly distributed on the surface thereof. The titanium dioxide nanowires are in-situ grown and evenly distributed on the surface of the magnesium hydroxide micron particles in a divergent shape. The average diameter of the titanium dioxide nanowires is 60nm and the average length is 410nm. The mass ratio of magnesium hydroxide micron particles to titanium dioxide nanowires is 81%:19%.

[0090] The thermoplastic polyurethane of this embodiment is composed of polyester thermoplastic polyurethane and polyether thermoplastic polyurethane in a mass ratio of 3:1.

[0091] The preparation method of the modified polyester masterbatch of the present embodiment is as follows: by weight, 68 parts of terephthalic acid, 46 parts of polyethylene glycol and 14 parts of benzimidazole monomers are added into a reaction kettle, heated to 176°C under a nitrogen atmosphere, then 0.05 parts of tetrabutyl titanate are added, and the mixture is heated to 230°C, and the copolymerization reaction is carried out at a stirring speed of 80 rpm and a stirring time of 85 min. After the reaction is completed, the mixture is cooled to room temperature and dried, and then granulated to obtain the modified polyester masterbatch. The preparation method of the benzimidazole monomer is as follows: at room temperature, 37 parts of sodium pyrosulfite, 31 parts of methyl p-formylbenzoate, and 34 parts of 3,4-diaminobenzoic acid are added to 300 parts of N,N-dimethylformamide by weight, and the mixture is evenly mixed, and the solution is heated to 132°C, stirred for 360 minutes, and after stirring is complete, it is poured into 500 parts of -2°C ice-water mixture, and then the upper suspension of the ice-water mixture is taken into a beaker, stirred at room temperature for 45 minutes, and then the suspension is filtered to remove the yellow precipitate, and then washed with deionized water 3 times, and finally vacuum dried at room temperature to obtain the benzimidazole monomer.

[0092] The cable core 1 of the present embodiment includes a plurality of conductors; each conductor is twisted by a plurality of tinned copper monofilaments; the diameter of the tinned copper monofilaments is 0.24 mm; the insulating layer 2 is a glass fiber tape; the thickness of the glass fiber tape is 0.16 mm; the insulating layer 3 is cross-linked polyethylene; the thickness of the insulating layer 3 is 1.9 mm; the shielding layer 4 is a shielding layer 4 woven of copper wires, the diameter of the copper wires is 0.16 mm, and the braiding density is 90%;

[0093] The present invention also provides a method for preparing an anti-UV environmentally friendly photovoltaic solar cable, comprising the following steps:

[0094] S1: A plurality of tinned copper monofilaments are twisted to form a conductor, and then the plurality of conductors are twisted to form a cable core 1;

[0095] S2: Winding the glass fiber tape around the outside of the cable core 1 to form an insulation layer 2;

[0096] S3: coating the insulating layer 2 with a layer of cross-linked polyethylene as the insulating layer 3 by an extrusion process;

[0097] S4: a shielding layer 4 is woven by copper wire outside the insulating layer 3;

[0098] S5: Add modified polyurethane masterbatch, modified polyester masterbatch, Irganox 1010 antioxidant and zinc stearate into a mixer, mix at a speed of 45 rpm for 12 min, then add into a twin-screw extruder, set the extrusion temperature to 200°C, the screw speed to 150 rpm, and then extrude an outer layer 5 on the outside of the shielding layer 4.

[0099] Example 4

[0100] A UV-resistant and environment-friendly photovoltaic solar cable comprises, from inside to outside, a cable core 1, an insulating layer 2, an insulating layer 3, a shielding layer 4 and an outer layer 5.

[0101] The outer layer 5 of this embodiment is a modified flame-retardant two-component polyurethane and polyester composite insulation material, which is prepared by melt extrusion after uniformly mixing 70 parts of modified polyurethane masterbatch, 50 parts of modified polyester masterbatch, 0.5 parts of Irganox 1010 antioxidant and 0.5 parts of zinc stearate.

[0102] The modified polyurethane masterbatch of this embodiment is obtained by melt extrusion granulation of surface-modified titanium dioxide / magnesium hydroxide filler, montmorillonite, thermoplastic polyurethane and zinc stearate; the surface-modified titanium dioxide / magnesium hydroxide filler is obtained by surface modification of titanium dioxide / magnesium hydroxide filler with γ-aminopropyltriethoxysilane; the modified polyester masterbatch is prepared by copolymerization of benzimidazole monomer, polyethylene glycol, tetrabutyl titanate and terephthalic acid, and then obtained by drying and pelletizing.

[0103] The preparation method of the modified polyurethane masterbatch of the present embodiment is as follows: by weight, 6.5 parts of surface modified titanium dioxide / magnesium hydroxide filler, 3.5 parts of montmorillonite, 65 parts of thermoplastic polyurethane and 1.5 parts of zinc stearate are added to a mixer, mixed at a speed of 1500 rpm for 10 min, and then added to a twin-screw extruder, the extrusion temperature is set to 200 ° C, the screw speed is 200 rpm, and then extrusion molding is performed, and finally granulation is performed to obtain a modified polyurethane masterbatch. The preparation method of the surface modified titanium dioxide / magnesium hydroxide filler is as follows: after mixing 3.5 parts of γ-aminopropyltriethoxysilane and 30 parts of ethanol by weight, 100 parts of deionized water are added drop by drop, and 16 parts of titanium dioxide / magnesium hydroxide filler are added after the addition is completed, and then the mixture is stirred and heated to 80°C for 120 minutes. After the stirring is completed, the mixed solution is filtered to retain the filter residue, and then the filter residue is washed once with deionized water, and finally the filter residue is completely vacuum dried at room temperature to obtain the surface modified titanium dioxide / magnesium hydroxide filler; The preparation method of the titanium dioxide / magnesium hydroxide filler is as follows: after mixing 35 parts of magnesium hydroxide micron particles, 5.0 parts of tetraisopropyl titanate and 100 parts of ethanol by weight, the mixture is added to a reactor, and then heated to 280°C, kept warm for 360 minutes for hydrothermal reaction, and then the hydrothermal reaction solution is filtered to retain the filter residue after cooling to room temperature, and then the filter residue is washed 3 times with ethanol, and finally the titanium dioxide / magnesium hydroxide filler is completely vacuum dried at room temperature.

[0104] The titanium dioxide / magnesium hydroxide filler of this embodiment is composed of magnesium hydroxide micron particles and titanium dioxide nanowires uniformly distributed on the surface thereof. The titanium dioxide nanowires are in-situ grown and evenly distributed on the surface of the magnesium hydroxide micron particles in a divergent shape. The average diameter of the titanium dioxide nanowires is 90nm and the average length is 650nm. The mass ratio of magnesium hydroxide micron particles to titanium dioxide nanowires is 90%:10%.

[0105] The thermoplastic polyurethane of this embodiment is composed of polyester thermoplastic polyurethane and polyether thermoplastic polyurethane in a mass ratio of 3:1.

[0106] The preparation method of the modified polyester masterbatch of the present embodiment is as follows: by weight, 80 parts of terephthalic acid, 55 parts of polyethylene glycol and 18 parts of benzimidazole monomers are added into a reaction kettle, heated to 185° C. under a nitrogen atmosphere, then 0.08 parts of tetrabutyl titanate are added, and the mixture is heated to 240° C. The copolymerization reaction is carried out at a stirring speed of 100 rpm and a stirring time of 120 min. After the reaction is completed, the mixture is cooled to room temperature and dried, and then granulated to obtain the modified polyester masterbatch. The preparation method of the benzimidazole monomer is as follows: at room temperature, by weight, 45 parts of sodium pyrosulfite, 35 parts of methyl p-formylbenzoate, and 38 parts of 3,4-diaminobenzoic acid are added to 300 parts of N,N-dimethylformamide and mixed evenly, the solution is heated to 140°C, stirred for 480 minutes, and after stirring completely, poured into 500 parts of 0°C ice-water mixture, and then the upper suspension of the ice-water mixture is taken into a beaker, stirred at room temperature for 60 minutes, and then the suspension is filtered to remove the yellow precipitate, and then washed with deionized water 3 times, and finally vacuum dried at room temperature to obtain the benzimidazole monomer.

[0107] The cable core 1 of the present embodiment includes a plurality of conductors; each conductor is twisted by a plurality of tinned copper monofilaments; the diameter of the tinned copper monofilaments is 0.32 mm; the insulating layer 2 is a glass fiber tape; the thickness of the glass fiber tape is 0.25 mm; the insulating layer 3 is cross-linked polyethylene; the thickness of the insulating layer 3 is 2.5 mm; the shielding layer 4 is a shielding layer 4 woven of copper wires, the diameter of the copper wires is 0.20 mm, and the braiding density is 95%;

[0108] The present invention also provides a method for preparing an anti-UV environmentally friendly photovoltaic solar cable, comprising the following steps:

[0109] S1: A plurality of tinned copper monofilaments are twisted to form a conductor, and then the plurality of conductors are twisted to form a cable core 1;

[0110] S2: Winding the glass fiber tape around the outside of the cable core 1 to form an insulation layer 2;

[0111] S3: coating the insulating layer 2 with a layer of cross-linked polyethylene as the insulating layer 3 by an extrusion process;

[0112] S4: a shielding layer 4 is woven by copper wire outside the insulating layer 3;

[0113] S5: Add modified polyurethane masterbatch, modified polyester masterbatch, Irganox 1010 antioxidant and zinc stearate into a mixer, mix at a speed of 60 rpm for 15 min, then add into a twin-screw extruder, set the extrusion temperature to 220°C, the screw speed to 200 rpm, and then extrude an outer layer 5 on the outside of the shielding layer 4.

[0114] Comparative Example 1

[0115] The method is basically the same as Example 1, except that titanium dioxide nanowires are not prepared on the surface of the magnesium hydroxide microparticles added to prepare the outer layer, but magnesium hydroxide microparticles in an amount equal to that of the titanium dioxide / magnesium hydroxide filler are added.

[0116] Comparative Example 2

[0117] The method is basically the same as Example 1, except that the outer layer is prepared by adding titanium dioxide nanowires in an amount equal to the amount of titanium dioxide / magnesium hydroxide filler.

[0118] The preparation method of titanium dioxide nanowires is as follows: by weight, 20 parts of magnesium hydroxide micron particles, 2.0 parts of tetraisopropyl titanate and 100 parts of ethanol are mixed evenly and added into a reactor, and then heated to 250°C and kept warm for 240 minutes for hydrothermal reaction, and then the hydrothermal reaction solution is filtered after cooling to room temperature to retain the filter residue, and then the filter residue is washed with ethanol for 3 times, and finally vacuum dried at room temperature to completely obtain titanium dioxide / magnesium hydroxide filler, and then the titanium dioxide / magnesium hydroxide filler is placed in 100 parts of hydrochloric acid with a mass fraction of 10%, stirred for reaction for 60 minutes, and then the solution is filtered to retain the filter residue, which is washed with deionized water for 3 times and finally vacuum dried.

[0119] Comparative Example 3

[0120] The method is basically the same as Example 1, except that the magnesium hydroxide micron particles and the titanium dioxide nanowires are added separately, so the titanium dioxide nanowires are not evenly distributed on the magnesium hydroxide micron particles. The preparation method of the titanium dioxide nanowires is the same as that of Comparative Example 2.

[0121] Comparative Example 4

[0122] The method is basically the same as Example 1, except that the titanium dioxide / magnesium hydroxide filler is not subjected to surface modification treatment.

[0123] Comparative Example 5

[0124] The method is basically the same as Example 1, except that no benzimidazole monomer is added to the modified polyester masterbatch.

[0125] Performance Testing:

[0126] 1. Tensile strength and elongation at break test

[0127] The tensile strength and elongation at break test is carried out according to GB / T 2951.12 standard, and the test is carried out using a tensile testing machine. Under the standard specimen size, by applying a tensile load to the cable outer material, the maximum stress (i.e. tensile strength) and the deformation at break (i.e. elongation at break) borne during the stretching process are recorded. The purpose of this test is to evaluate the mechanical properties of the cable outer material, including its strength and ductility under external force, so as to provide data support for judging the tensile strength of the material in actual use.

[0128] 2. Thermal shock resistance test

[0129] The heat shock resistance test is carried out according to GB / T 2951.31 standard. The test lasts for 3 hours in an environment of (150±1°C). The cable outer material is placed in a high temperature environment and then subjected to an impact test to observe the performance changes of the material. This test is used to evaluate the heat resistance and impact resistance of the cable outer material under high temperature conditions, which can reflect the stability and reliability of the material in extreme temperature environments, especially its application range under high temperature.

[0130] 3. Flame retardant performance test

[0131] The flame retardant performance test is carried out according to the UL 94 standard. The cable outer material is placed in a flame to test its combustion performance, including burning time, burning degree and whether it will self-extinguish. By observing and recording the burning behavior of the cable outer material in the flame, the test can evaluate the flame retardant performance of the material and determine its safety and fire resistance in extreme situations such as fire. This is of great significance for the safety evaluation of the cable outer material.

[0132] 4. Thermal deformation test

[0133] The heat deformation test is carried out according to UL 1581 standard. The deformation of the cable outer material is tested under high temperature conditions of 150°C. By continuously heating the material in a high temperature environment, observing its deformation degree, and evaluating its stability and deformation resistance under high temperature. This test is used to analyze the applicability of the cable outer material in high temperature occasions, especially its reliability and deformation resistance under long-term high temperature working conditions.

[0134] 5. Resistivity test

[0135] The resistivity test is carried out in accordance with GB / T 1410-2006 standard at 20°C. By measuring the volume resistivity of the cable outer material, this test can evaluate the electrical insulation performance of the material at room temperature. Resistivity is an important parameter for measuring the electrical performance of the cable outer material, and can reflect the electrical safety and stability of the material under normal working conditions.

[0136] 6. UV resistance test

[0137] The UV resistance test is conducted through a UV aging test. The test conditions are to irradiate the cable outer material with a 6kW xenon lamp for a total exposure time of 1000 hours. After that, the material is placed at room temperature for 20 hours to observe whether there are any aging phenomena such as cracks on its appearance. At the same time, the tensile strength and elongation at break of the cable outer material are tested before and after the aging test, and the change rate (i.e. the ratio of tensile strength and elongation at break after the experiment to that before the experiment) is calculated. This test is used to evaluate the aging performance of the cable outer material under long-term UV irradiation and the changes in its mechanical properties, so as to determine the long-term reliability of the material in UV exposure environments such as outdoor.

[0138] The properties of the cable outer layer materials of Examples 1 to 4 and Comparative Examples 1 to 5 are summarized in Table 2.

[0139] Table 2 Performance summary of cable outer layer materials of Examples 1 to 4 and Comparative Examples 1 to 5

[0140]

[0141] As shown in Table 2, the main difference between Comparative Example 1 and Example 1 is that magnesium hydroxide microparticles are added to the outer layer material of the cable in Comparative Example 1, while titanium dioxide nanowires are introduced on the surface of magnesium hydroxide microparticles in Example 1. As can be seen from Table 2, the tensile strength and elongation at break of Example 1 are significantly better than those of Comparative Example 1. This is because the uniform distribution of titanium dioxide nanowires can effectively enhance the mechanical properties of the material, improve the stress dispersion effect, and enhance the strength and ductility of the material. In the heat shock test, Example 1 exhibits better high temperature resistance and impact resistance, which is mainly because the titanium dioxide nanowires maintain structural stability in a high temperature environment and reduce thermal damage to the material. In terms of flame retardant properties, the flame retardant effect of Example 1 is also better than that of Comparative Example 1. Titanium dioxide nanowires improve the thermal stability of the material, making it exhibit a slower burning speed and better self-extinguishing ability in the flame. In the thermal deformation test, the deformation resistance of Example 1 is significantly better than that of Comparative Example 1. The high thermal stability of titanium dioxide nanowires enables the material to maintain structural integrity at high temperatures. The resistivity test shows that the electrical insulation performance of Example 1 is better than that of Comparative Example 1, which may be due to the fact that the titanium dioxide nanowires improve the electrical insulation of the material. In the UV resistance test, Example 1 maintains good appearance and mechanical properties after UV aging, while Comparative Example 1 shows obvious cracking after aging due to the lack of protection of titanium dioxide nanowires, indicating that Example 1 has better UV resistance.

[0142] The main difference between Comparative Example 2 and Example 1 is that only titanium dioxide nanowires are added in Comparative Example 2, and magnesium hydroxide microparticles are not used. As can be seen from Table 2, the tensile strength and elongation at break of Example 1 are better than those of Comparative Example 2. This is because the synergistic effect of titanium dioxide nanowires and magnesium hydroxide microparticles can better disperse stress and improve the mechanical properties of the material, while the effect of using titanium dioxide nanowires alone is limited. In the heat shock test, Example 1 exhibits stronger high-temperature impact resistance, which is due to the combination of magnesium hydroxide microparticles and titanium dioxide nanowires to enhance the high-temperature stability of the material, while Comparative Example 2 lacks the effect of magnesium hydroxide microparticles and has poor heat shock resistance. The flame retardant test shows that the flame retardant effect of Example 1 is better than that of Comparative Example 2, and the combination of magnesium hydroxide microparticles and titanium dioxide nanowires more effectively improves the fire resistance of the material. In the thermal deformation test, the deformation resistance of Example 1 is also better than that of Comparative Example 2, and the magnesium hydroxide microparticles can prevent thermal deformation of the material at high temperatures. The resistivity test shows that the electrical insulation performance of Example 1 is slightly higher than that of Comparative Example 2, and the combination of titanium dioxide nanowires and magnesium hydroxide microparticles further improves the electrical performance of the material. The UV resistance test shows that the UV resistance of Example 1 is significantly better than that of Comparative Example 2, and the synergistic effect of titanium dioxide nanowires and magnesium hydroxide microparticles is more effective in resisting UV erosion.

[0143] The main difference between Comparative Example 3 and Example 1 is that in Comparative Example 3, magnesium hydroxide micron particles and titanium dioxide nanowires are added separately and fail to achieve uniform distribution. As can be seen from Table 2, the tensile strength and elongation at break of Example 1 are significantly better than those of Comparative Example 3. This is because the titanium dioxide nanowires are evenly distributed on the magnesium hydroxide micron particles, which can effectively disperse stress and enhance mechanical properties, while the mechanical properties of Comparative Example 3 are reduced due to uneven distribution. In the heat shock test, Example 1 exhibits better high temperature impact resistance, which is mainly due to the uniform distribution of titanium dioxide nanowires and magnesium hydroxide micron particles, which enhances the stability at high temperatures, while Comparative Example 3 has poor heat shock resistance due to uneven distribution. The flame retardant test shows that the flame retardant effect of Example 1 is better than that of Comparative Example 3, and the evenly distributed titanium dioxide nanowires and magnesium hydroxide micron particles jointly improve the fire resistance of the material. In the thermal deformation test, the deformation resistance of Example 1 is also better than that of Comparative Example 3, and the evenly distributed material can effectively reduce deformation at high temperatures. The resistivity test shows that the electrical insulation performance of Example 1 is better than that of Comparative Example 3, and the uniformly distributed filler enhances the electrical performance. The UV resistance test shows that the performance of Example 1 after UV aging is better than that of Comparative Example 3, and the uniformly distributed titanium dioxide nanowires and magnesium hydroxide microparticles can better resist UV erosion and delay material aging.

[0144] The main difference between Comparative Example 4 and Example 1 is that the titanium dioxide / magnesium hydroxide filler in Comparative Example 4 is not surface modified. As can be seen from Table 2, the tensile strength and elongation at break of Example 1 are better than those of Comparative Example 4. This is because the surface modification can improve the interface bonding between the filler and the matrix and enhance the mechanical properties of the material, while the unmodified filler in Comparative Example 4 has poor dispersibility and low mechanical properties. In the heat shock test, Example 1 shows better high temperature impact resistance, and the filler after surface modification has better stability at high temperature, while Comparative Example 4 has poor performance at high temperature due to the unmodified filler. The flame retardant performance test shows that the flame retardant effect of Example 1 is significantly better than that of Comparative Example 4, and the filler after surface modification can better play its flame retardant role and improve the thermal stability of the material. In the thermal deformation test, the deformation resistance of Example 1 is better than that of Comparative Example 4, and the filler after surface modification can enhance the material stability at high temperature and reduce deformation. The resistivity test shows that the electrical insulation performance of Example 1 is better than that of Comparative Example 4, and the surface modification improves the dispersibility and interface compatibility of the filler and enhances the electrical performance. The UV resistance test shows that the performance of Example 1 after UV aging is better than that of Comparative Example 4, and the surface-modified filler exhibits better stability and anti-aging ability under UV irradiation.

[0145] The main difference between Comparative Example 5 and Example 1 is that no benzimidazole monomer is added to the modified polyester masterbatch in Comparative Example 5. As can be seen from Table 2, the tensile strength and elongation at break of Example 1 are significantly better than those of Comparative Example 5. This is because the introduction of benzimidazole monomer can enhance the mechanical properties of the material, improve its tensile strength and ductility, while Comparative Example 5 has poor mechanical properties due to the lack of the addition of the monomer. In the heat shock resistance test, Example 1 exhibits better high temperature resistance and impact resistance. The addition of benzimidazole monomer improves the stability of the material in a high temperature environment, while Comparative Example 5 has poor performance at high temperatures. The flame retardant performance test shows that the flame retardant effect of Example 1 is better than that of Comparative Example 5. The heat resistance and flame retardancy of the benzimidazole monomer enhance the fire resistance of the material, while Comparative Example 5 does not add the monomer and has weak flame retardant performance. In the thermal deformation test, the deformation resistance of Example 1 is significantly better than that of Comparative Example 5. The introduction of benzimidazole monomer enhances the stability of the material at high temperatures and reduces thermal deformation. The resistivity test shows that the electrical insulation performance of Example 1 is better than that of Comparative Example 5, and the addition of benzimidazole monomer improves the electrical performance of the material.

[0146] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that all equivalent structural changes made under the concept of the present invention and using the contents of the present invention specification and drawings should be covered within the scope of protection of the claims of the present invention.

Claims

1. A UV-resistant and environmentally friendly photovoltaic solar cable, characterized in that: From inside to outside, the cable core (1), the insulating layer (2), the insulation layer (3), the shielding layer (4) and the outer layer (5) are arranged in order; The outer layer (5) is a modified flame-retardant two-component polyurethane and polyester composite insulation material, which is prepared by uniformly mixing 50-70 parts of modified polyurethane masterbatch, 30-50 parts of modified polyester masterbatch, 0.1-0.5 parts of antioxidant and 0.1-0.5 parts of zinc stearate by weight and then melt extruding; The modified polyurethane masterbatch is obtained by melt extrusion granulation of surface-modified titanium dioxide / magnesium hydroxide filler, montmorillonite, thermoplastic polyurethane and zinc stearate; The surface-modified titanium dioxide / magnesium hydroxide filler is obtained by surface-modifying the titanium dioxide / magnesium hydroxide filler with γ-aminopropyltriethoxysilane; The modified polyester masterbatch is prepared by copolymerization of benzimidazole monomer, polyethylene glycol, tetrabutyl titanate and terephthalic acid, and then dried and pelletized; The titanium dioxide / magnesium hydroxide filler is composed of magnesium hydroxide micron particles and titanium dioxide nanowires uniformly distributed on the surface; The titanium dioxide nanowires are in-situ grown and evenly distributed on the surface of the magnesium hydroxide micron particles in a divergent manner; The average diameter of the titanium dioxide nanowires is 30-90 nm, and the average length is 200-650 nm; The mass ratio of the magnesium hydroxide micron particles to the titanium dioxide nanowires is (75-90):(10-25); The preparation method of the titanium dioxide / magnesium hydroxide filler is as follows: by weight, 20-35 parts of magnesium hydroxide micron particles, 2.0-5.0 parts of tetraisopropyl titanate and 100 parts of ethanol are mixed evenly and added into a reaction kettle, and then heated to 250-280° C., kept warm for 240-360 minutes for hydrothermal reaction, and then cooled to room temperature, the hydrothermal reaction solution is filtered to retain the filter residue, and then the filter residue is washed with ethanol for 3 times, and finally vacuum dried at room temperature to completely obtain the titanium dioxide / magnesium hydroxide filler.

2. The UV-resistant and environmentally friendly photovoltaic solar cable according to claim 1, characterized in that: The preparation method of the modified polyurethane masterbatch is as follows: by weight, 2.5-6.5 parts of surface modified titanium dioxide / magnesium hydroxide filler, 1.5-3.5 parts of montmorillonite, 30-65 parts of thermoplastic polyurethane and 0.5-1.5 parts of zinc stearate are added to a mixer, mixed at a speed of 1000-1500 rpm for 5-10 minutes, then added to a twin-screw extruder, the extrusion temperature is set to 180-200°C, the screw speed is set to 100-200 rpm, then extruded and formed, and finally granulated to obtain the modified polyurethane masterbatch.

3. The UV-resistant and environmentally friendly photovoltaic solar cable according to claim 2, characterized in that: The preparation method of the surface modified titanium dioxide / magnesium hydroxide filler is as follows: after 1.0-3.5 parts of γ-aminopropyltriethoxysilane and 30 parts of ethanol are mixed evenly by weight, 100 parts of deionized water are added drop by drop, and after the addition is completed, 8-16 parts of titanium dioxide / magnesium hydroxide filler are added, followed by stirring and heating to 50-80°C for 60-120 minutes. After the stirring is completed, the mixed solution is filtered to retain the filter residue, and the filter residue is washed once with deionized water, and finally the filter residue is completely vacuum dried at room temperature to obtain the surface modified titanium dioxide / magnesium hydroxide filler.

4. The UV-resistant and environmentally friendly photovoltaic solar cable according to claim 1, characterized in that: The thermoplastic polyurethane is composed of polyester thermoplastic polyurethane and polyether thermoplastic polyurethane in a mass ratio of 3:

1.

5. The UV-resistant and environmentally friendly photovoltaic solar cable according to claim 1, characterized in that: The preparation method of the modified polyester masterbatch is as follows: by weight, 60-80 parts of terephthalic acid, 40-55 parts of polyethylene glycol and 10-18 parts of benzimidazole monomers are added into a reaction kettle, heated to 170-185° C. under a nitrogen atmosphere, then 0.02-0.08 parts of tetrabutyl titanate are added, and the mixture is heated to 220-240° C., and the mixture is subjected to copolymerization reaction at a stirring speed of 60-100 rpm and a stirring time of 60-120 min. After the reaction is completed, the mixture is cooled to room temperature, dried and granulated to obtain the modified polyester masterbatch. The preparation method of the benzimidazole monomer is as follows: at room temperature, by weight, 30-45 parts of sodium pyrosulfite, 28-35 parts of methyl p-formylbenzoate, and 30-38 parts of 3,4-diaminobenzoic acid are added to 300 parts of N,N-dimethylformamide and mixed evenly, the solution is heated to 120-140°C, stirred for 240-480 minutes, and after stirring completely, poured into 500 parts of -5-0°C ice-water mixture, and then the upper suspension of the ice-water mixture is taken into a beaker, stirred at room temperature for 30-60 minutes, and then the suspension is filtered to remove yellow precipitate, and then washed with deionized water for 3 times, and finally vacuum dried at room temperature to obtain the benzimidazole monomer.

6. The UV-resistant and environmentally friendly photovoltaic solar cable according to claim 1, characterized in that: The cable core (1) comprises a plurality of conductors; each conductor is formed by twisting a plurality of tinned copper monofilaments (11); the diameter of the tinned copper monofilaments (11) is 0.15-0.32 mm; The insulating layer (2) is a glass fiber tape; the thickness of the glass fiber tape is 0.1-0.25 mm; The insulating layer (3) is cross-linked polyethylene; the thickness of the insulating layer (3) is 1.0-2.5 mm; The shielding layer (4) is a shielding layer woven from copper wires, the diameter of the copper wires is 0.12-0.20 mm, and the braiding density is 85-95%.

7. A method for preparing a UV-resistant and environmentally friendly photovoltaic solar cable according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1: twisting a plurality of tinned copper monofilaments (11) to form a conductor, and then twisting the plurality of conductors to form a cable core (1); S2: Winding a glass fiber tape around the outside of the cable core (1) to form an insulating layer (2); S3: coating the insulating layer (2) with a layer of cross-linked polyethylene as the insulating layer (3) by an extrusion process; S4: a shielding layer (4) is woven with copper wires outside the insulating layer (3); S5: Add modified polyurethane masterbatch, modified polyester masterbatch, antioxidant and zinc stearate into a mixer, mix at a speed of 30-60 rpm for 10-15 min, then add into a twin-screw extruder, set the extrusion temperature at 180-220°C, the screw speed at 100-200 rpm, and then extrude an outer layer (5) on the outside of the shielding layer (4).

8. Application of the UV-resistant and environmentally friendly photovoltaic solar cable as described in any one of claims 1 to 7 in solar power stations, rooftop solar panel systems, and photovoltaic agricultural facilities.

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