Junction box material and preparation method thereof

Abstract

The invention belongs to the technical field of high polymer materials, and discloses a junction box material and a preparation method thereof, the junction box material comprises the following raw materials by weight: 40-55 parts of PPE resin, 25-35 parts of PPS resin, 8-12 parts of modified carbon fiber, 2-5 parts of an insulating filler, 3-8 parts of a compatilizer, 0.5-2 parts of a modified ultraviolet absorbent, 3-5 parts of a fluidity improver, 1-2 parts of an antioxidant, and 1.5-3 parts of a lubricant. According to the junction box material provided by the invention, through scientific formula system design and a targeted component modification scheme, the technical bottleneck that an existing junction box material is difficult to consider mechanical properties, weather resistance, heat dissipation, insulativity and processing suitability at the same time is effectively broken through. All core components and a modification process have a synergistic effect, so that the material is endowed with balanced and excellent comprehensive performance and can stably adapt to complicated and harsh application working conditions such as outdoor exposure, high-temperature work, electrical interference and mechanical collision, and long-term safe and reliable use of the junction box is guaranteed.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, and specifically relates to a junction box material and its preparation method. Background Technology

[0002] Junction boxes, as core components for circuit connection and protection in electrical equipment, are widely used in industrial control, new energy, outdoor electrical and other fields. Their working environment often faces multiple stringent requirements such as high temperature, long-term ultraviolet radiation, mechanical impact and electrical insulation.

[0003] Existing materials used for manufacturing junction boxes often struggle to simultaneously achieve key performance indicators such as impact strength, weather resistance, heat dissipation, insulation, and processability. Traditional resin matrix materials are prone to thermal deformation under high-temperature conditions and have poor compatibility with reinforcing fillers, resulting in insufficient impact strength. Junction boxes may crack and be damaged by minor impacts during transportation or use. While reinforcing fillers such as carbon fibers introduced to improve mechanical properties can enhance strength and heat dissipation, unmodified fillers can easily form interfacial gaps with the resin matrix. This not only affects the full realization of mechanical properties but may also lead to a decrease in insulation performance due to the conductivity of the fillers themselves, posing electrical safety hazards. Furthermore, the UV absorbers added to existing materials are mostly small molecules that are prone to migration and loss during long-term use, leading to a decline in weather resistance. After UV irradiation, the materials may yellow and become brittle, shortening the service life of the junction boxes. In addition, highly filled materials often have high melt viscosity and poor flowability, making injection molding of complex junction box structures difficult and prone to problems such as incomplete mold filling and demolding defects, affecting production efficiency and product yield. These problems make it difficult for existing junction box materials to meet the requirements for long-term stable use under complex working conditions, thus limiting the application of junction boxes in high-end electrical equipment. Summary of the Invention

[0004] The present invention aims to improve at least one technical problem in the prior art.

[0005] The first aspect of this invention provides a junction box material, the raw materials comprising, by weight: 40-55 parts of PPE resin, 25-35 parts of PPS resin, 8-12 parts of modified carbon fiber, 2-5 parts of insulating filler, 3-8 parts of compatibilizer, 0.5-2 parts of modified ultraviolet absorber, 3-5 parts of flowability improver, 1-2 parts of antioxidant, and 1.5-3 parts of lubricant; Modified carbon fiber is obtained by coating the surface of carbon fiber with a composite slurry, which is obtained by mixing bisphenol A epoxy resin and γ-glycidoxypropyltrimethoxysilane. The compatibilizer contains thiol groups; The modified ultraviolet absorber is obtained by modifying the ultraviolet absorber with a silane coupling agent.

[0006] The junction box material provided in this application is specifically adapted to the working environment and performance requirements of junction boxes, with each component working synergistically to form a material system with excellent comprehensive performance. PPE resin, as the core matrix, imparts good high-temperature resistance and dimensional stability to the material, laying the foundation for overall performance. PPS resin works synergistically with PPE resin to reduce the melt viscosity of PPE to improve processing fluidity, and to enhance the material's high-temperature resistance, flame retardancy, and chemical corrosion resistance, further adapting to the complex working conditions of junction boxes. The modified carbon fiber surface is coated with bisphenol A epoxy resin, which retains the high specific strength and thermal conductivity of the carbon fiber itself, effectively improving the material's impact strength and assisting in heat dissipation, preventing heat accumulation inside the junction box. The coating layer also enhances the interfacial bonding force with the resin matrix, preventing debonding during use. The insulating filler specifically improves the material's insulation performance, blocking potential conductive paths and meeting the stringent electrical safety requirements of junction boxes. The compatibilizer contains thiol groups that not only optimize the compatibility between PPE and PPS, promoting uniform blending of the two resins, but also form a stable bond with the modified UV absorber, preventing the UV absorber from migrating and being lost during use. The modified UV absorber, after being modified with a silane coupling agent, exhibits significantly improved compatibility with the non-polar PPE / PPS system, enabling it to exert a long-lasting UV absorption effect, delaying the aging and degradation of the material in outdoor environments, and ensuring the long-term performance stability of the junction box. The flowability improver, without affecting the material's core properties such as high-temperature resistance and mechanical properties, reduces the melt viscosity of the high-filler system, ensuring the integrity of the complex junction box structure during molding and improving injection molding efficiency. The antioxidant inhibits oxidative degradation of the material during high-temperature processing and long-term use, extending the service life of the junction box. The lubricant reduces friction within the material and between the material and processing equipment during processing, improving melt flowability and demolding effect, and reducing the incidence of molding defects in the junction box. The scientifically proportioned and synergistic effects of these components give the junction box material excellent impact strength, weather resistance, heat dissipation, insulation, and processing adaptability, meeting the long-term stable use requirements of the junction box under complex working conditions.

[0007] The preparation method of modified carbon fiber includes the following steps: The carbon fiber was impregnated in the composite slurry for 10-15 minutes and then dried to obtain the modified carbon fiber. The composite slurry is obtained by mixing bisphenol A epoxy resin and γ-glycidoxypropyltrimethoxysilane in a mass ratio of (3-5):1.

[0008] This application utilizes a composite slurry formed by mixing bisphenol A epoxy resin and γ-glycidoxypropyltrimethoxysilane in a specific ratio. This slurry not only leverages the adhesive properties of the epoxy resin to form a uniform coating layer on the carbon fiber surface, but also enhances the compatibility between the carbon fiber and the PPE / PPS resin matrix through the functional groups of the silane coupling agent. Impregnation ensures that the slurry fully wets the carbon fiber surface, while subsequent drying treatment stabilizes and cures the coating layer. The resulting modified carbon fiber is tightly bonded to other components, fully exerting its mechanical reinforcement and heat dissipation auxiliary functions, and ensuring the overall stability of the material's performance.

[0009] Preferably, the ultraviolet absorber is one of 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxyphenol, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, 2-hydroxy-4-n-octyloxybenzophenone, and phenyl o-hydroxybenzoate; the silane coupling agent is one of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, and γ-mercaptopropyltrimethoxysilane.

[0010] Preferably, the modified UV absorber is obtained by ring-opening addition reaction of 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxyphenol and γ-aminopropyltriethoxysilane in a molar ratio of 1:(0.01-0.02).

[0011] The preferred modified UV absorber in this application is prepared by a ring-opening addition reaction of 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxyphenol and γ-aminopropyltriethoxysilane in a specific molar ratio. This combination utilizes the excellent UV absorption efficiency and temperature resistance of the former, and improves its compatibility with the PPE / PPS system through the modification effect of the silane coupling agent, ensuring the long-term stable function of the UV absorber and preventing it from migrating or being lost.

[0012] Preferably, the compatibilizer is a mercapto-styrene-methacrylate copolymer.

[0013] The preferred compatibilizer in this application is a mercapto-modified styrene-methacrylate copolymer. The mercapto groups in its molecular structure can form a stable bond with the modified ultraviolet absorber. At the same time, the styrene-methacrylate skeleton can be well adapted to the PPE / PPS resin matrix, significantly improving the interfacial compatibility between different components, promoting uniform dispersion of the system, and further enhancing the comprehensive performance of the material.

[0014] Preferably, the insulating filler is at least one selected from tourmaline powder, α-alumina, fumed silica, and boron nitride.

[0015] Preferably, the flowability improver is a hyperbranched polyester-polysiloxane block copolymer.

[0016] The preferred flowability improver in this application is a hyperbranched polyester-polysiloxane block copolymer. Its hyperbranched structure can effectively reduce the melt viscosity of the material, while the polysiloxane segments ensure temperature resistance. While improving processing flowability and ensuring the complete filling of the complex structure of the junction box, it will not have a negative impact on the core indicators such as the mechanical properties and insulation of the material, making it suitable for high-temperature processing conditions.

[0017] Preferably, the antioxidant is at least one of antioxidant 1010, antioxidant 168, antioxidant 245 and antioxidant 1076.

[0018] Preferably, the lubricant is at least one of pentaerythritol tetrastearate, silicone powder, polyethylene wax, and ethylene bis-stearamide.

[0019] A second aspect of the present invention provides a method for preparing the above-mentioned junction box material, comprising the following steps: The raw materials are mixed, melted, extruded, and granulated to obtain the junction box material.

[0020] The beneficial effects of this invention: The junction box material provided by this invention, through a scientifically designed formula system and targeted component modification scheme, effectively overcomes the technical bottleneck of existing junction box materials that struggle to simultaneously achieve mechanical properties, weather resistance, heat dissipation, insulation, and processing adaptability. The synergistic effect of each core component and modification process endows the material with balanced and excellent comprehensive performance, enabling it to stably adapt to complex and demanding application conditions such as outdoor exposure, high-temperature operation, electrical interference, and mechanical impact, ensuring the long-term safe and reliable use of the junction box. Detailed Implementation

[0021] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the description of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0022] Example 1 A junction box material, the raw materials of which, by weight, include: 48 parts PPE resin, 30 parts PPS resin, 10 parts modified carbon fiber, 3 parts insulating filler (tourmaline powder), 5 parts compatibilizer (thiolized styrene-methacrylate copolymer), 1.2 parts modified ultraviolet absorber, 4 parts flow improver (hyperbranched polyester-polysiloxane block copolymer), 1.5 parts antioxidant (antioxidant 1010), and 2 parts lubricant (pentaerythritol tetrastearate).

[0023] The modified carbon fiber is obtained by coating the surface of carbon fiber with a composite slurry. The composite slurry is obtained by mixing bisphenol A epoxy resin and γ-glycidyl etheroxypropyltrimethoxysilane in a mass ratio of 4:1. The preparation method of the modified carbon fiber includes the following steps: impregnating the carbon fiber in the composite slurry at room temperature for 15 min, and then drying it in an oven at 70°C for 2.5 h to obtain the modified carbon fiber.

[0024] The modified ultraviolet absorber is obtained by ring-opening addition reaction of 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxy-phenol and γ-aminopropyltriethoxysilane in a molar ratio of 1:0.015. The preparation method of the modified ultraviolet absorber includes the following steps: 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxy-phenol and γ-aminopropyltriethoxysilane are added to a reaction vessel, and 0.8% of the total mass of 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxy-phenol and γ-aminopropyltriethoxysilane are added as a catalyst. The mixture is heated to 85°C under nitrogen protection and stirred for 3 hours. After the reaction is completed, it is cooled to room temperature, and low-boiling substances are removed by vacuum distillation. Then, it is dried in a vacuum drying oven at 80°C for 4 hours to obtain the modified ultraviolet absorber.

[0025] The preparation method of the mercapto-styrene-methacrylate copolymer includes the following steps: styrene, methyl methacrylate and mercaptoethanol are weighed in a mass ratio of 65:30:5 and added to a reaction vessel. Then, 0.5% of azobisisobutyronitrile (AIBN) of the total mass of styrene, methyl methacrylate and mercaptoethanol is added as an initiator. The temperature is raised to 70°C under a nitrogen atmosphere and the reaction is stirred for 6 hours. After the reaction is completed, the product is poured into methanol to precipitate. The precipitate is collected by filtration and dried under vacuum at 80°C for 6 hours to obtain the mercapto-styrene-methacrylate copolymer.

[0026] The preparation method of the hyperbranched polyester-polysiloxane block copolymer includes the following steps: 2,2-bis(hydroxymethyl)butyric acid and trimethylolpropane are added to a reaction vessel at a molar ratio of 24:1, and melt polycondensed at 160°C for 4 hours to obtain a hydroxyl-terminated hyperbranched polyester; then glycidyl etheroxypropyl-terminated polydimethylsiloxane (the mass ratio of hydroxyl-terminated hyperbranched polyester to glycidyl etheroxypropyl-terminated polydimethylsiloxane is 1:150) is added, and stannous octoate is added as a catalyst (the mass ratio of hydroxyl-terminated hyperbranched polyester to stannous octoate is 100:0.2), and the ring-opening grafting reaction is carried out at 100°C for 3 hours. After cooling, the product is discharged to obtain the hyperbranched polyester-polysiloxane block copolymer.

[0027] The preparation method of this junction box material includes the following steps: The raw materials for the junction box were put into a high-speed mixer and mixed (mixed at 800 rpm for 30 min) to obtain mixture A; Mixture A is fed into a twin-screw extruder for melting and extrusion to obtain mixture B. The main feed rate is 30 kg / h, and the temperature of each zone of the twin-screw extruder is set as follows: Zone 1 150℃, Zone 2 280℃, Zone 3 290℃, Zones 4 to 10 290℃, Die 300℃, Screw speed 400 rpm, and Vacuum degree -0.07 MPa. Mixture B is cooled by water at 40°C and then granulated by a pelletizer to obtain junction box material.

[0028] Example 2 A junction box material, the raw materials of which, by weight, include: 52 parts PPE resin, 28 parts PPS resin, 11 parts modified carbon fiber, 4 parts insulating filler (α-alumina), 6 parts compatibilizer (thiolized styrene-methacrylate copolymer), 0.8 parts modified ultraviolet absorber, 3.5 parts flowability improver (hyperbranched polyester-polysiloxane block copolymer), 1.2 parts antioxidant (antioxidant 168), and 2.5 parts lubricant (silicone powder).

[0029] The modified carbon fiber is obtained by coating the surface of carbon fiber with a composite slurry. The composite slurry is obtained by mixing bisphenol A epoxy resin and γ-glycidyl etheroxypropyltrimethoxysilane in a mass ratio of 3:1. The preparation method of the modified carbon fiber includes the following steps: impregnating the carbon fiber in the composite slurry at room temperature for 10 min, and then drying it in a 70℃ oven for 2 h to obtain the modified carbon fiber.

[0030] The modified ultraviolet absorber is obtained by ring-opening addition reaction of 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxy-phenol and γ-aminopropyltriethoxysilane in a molar ratio of 1:0.01. The preparation method of the modified ultraviolet absorber includes the following steps: 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxy-phenol and γ-aminopropyltriethoxysilane are added to a reaction vessel, and 0.6% of the total mass of 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxy-phenol and γ-aminopropyltriethoxysilane are added as a catalyst. The mixture is heated to 80°C under nitrogen protection and stirred for 3.5 h. After the reaction is completed, it is cooled to room temperature, and low-boiling substances are removed by vacuum distillation. Then, it is dried in a vacuum drying oven at 80°C for 4 h to obtain the modified ultraviolet absorber.

[0031] The preparation method of the mercapto-styrene-methacrylate copolymer is the same as in Example 1.

[0032] The preparation method of the hyperbranched polyester-polysiloxane block copolymer is the same as in Example 1.

[0033] The preparation method of this junction box material includes the following steps: The raw materials for the junction box material were put into a high-speed mixer and mixed (mixed at 750 rpm for 30 min) to obtain mixture A. Mixture A is fed into a twin-screw extruder for melting and extrusion to obtain mixture B. The main feed rate is 28 kg / h, and the temperature of each zone of the twin-screw extruder is set as follows: Zone 1 140℃, Zone 2 275℃, Zone 3 285℃, Zones 4 to 10 285℃, and Die 295℃. The screw speed is 380 rpm and the vacuum degree is -0.06 MPa. Mixture B is cooled by water at 38°C and then granulated by a pelletizer to obtain junction box material.

[0034] Example 3 A junction box material, the raw materials of which, by weight, include: 45 parts PPE resin, 32 parts PPS resin, 9 parts modified carbon fiber, 2.5 parts insulating filler (fumed silica), 4 parts compatibilizer (thiolized styrene-methacrylate copolymer), 1.8 parts modified ultraviolet absorber, 4.5 parts flowability improver (hyperbranched polyester-polysiloxane block copolymer), 1.8 parts antioxidant (antioxidant 1076), and 1.8 parts lubricant (polyethylene wax).

[0035] The modified carbon fiber is obtained by coating the surface of carbon fiber with a composite slurry. The composite slurry is obtained by mixing bisphenol A epoxy resin and γ-glycidyl etheroxypropyltrimethoxysilane in a mass ratio of 5:1. The preparation method of the modified carbon fiber includes the following steps: impregnating the carbon fiber in the composite slurry at room temperature for 12 min, and then drying it in an oven at 70℃ for 3 h to obtain the modified carbon fiber.

[0036] The modified ultraviolet absorber is obtained by ring-opening addition reaction of 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxy-phenol and γ-aminopropyltriethoxysilane in a molar ratio of 1:0.02. The preparation method of the modified ultraviolet absorber includes the following steps: 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxy-phenol and γ-aminopropyltriethoxysilane are added to a reaction vessel, and 1.0% of the total mass of 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxy-phenol and γ-aminopropyltriethoxysilane are added as a catalyst. The mixture is heated to 90°C under nitrogen protection and stirred for 2.5 h. After the reaction is completed, it is cooled to room temperature, and low-boiling substances are removed by vacuum distillation. Then, it is dried in a vacuum drying oven at 80°C for 4 h to obtain the modified ultraviolet absorber.

[0037] The preparation method of the mercapto-styrene-methacrylate copolymer is the same as in Example 1.

[0038] The preparation method of the hyperbranched polyester-polysiloxane block copolymer is the same as in Example 1.

[0039] The preparation method of this junction box material includes the following steps: The raw materials for the junction box material were put into a high-speed mixer and mixed (mixed at 850 rpm for 20 min) to obtain mixture A. Mixture A is fed into a twin-screw extruder for melting and extrusion to obtain mixture B. The main feed rate is 32 kg / h, and the temperature of each zone of the twin-screw extruder is set as follows: Zone 1 160℃, Zone 2 285℃, Zone 3 295℃, Zones 4 to 10 295℃, Die 305℃, Screw speed 420 rpm, Vacuum degree -0.08 MPa. Mixture B is cooled by water at 40°C and then granulated by a pelletizer to obtain junction box material.

[0040] Example 4 A junction box material, the raw materials of which, by weight, include: 50 parts PPE resin, 25 parts PPS resin, 12 parts modified carbon fiber, 5 parts insulating filler (boron nitride), 8 parts compatibilizer (thiolized styrene-methacrylate copolymer), 0.5 parts modified ultraviolet absorber, 3 parts flow improver (hyperbranched polyester-polysiloxane block copolymer), 1 part antioxidant (antioxidant 245), and 3 parts lubricant (ethylene bis-stearamide).

[0041] The modified carbon fiber is obtained by coating the surface of carbon fiber with a composite slurry. The composite slurry is obtained by mixing bisphenol A epoxy resin and γ-glycidyl etheroxypropyltrimethoxysilane in a mass ratio of 4:1. The preparation method of the modified carbon fiber includes the following steps: impregnating the carbon fiber in the composite slurry at room temperature for 10 min, and then drying it in an oven at 70℃ for 2 h to obtain the modified carbon fiber.

[0042] The modified ultraviolet absorber is obtained by ring-opening addition reaction of 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxy-phenol and γ-aminopropyltriethoxysilane in a molar ratio of 1:0.018. The preparation method of the modified ultraviolet absorber includes the following steps: 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxy-phenol and γ-aminopropyltriethoxysilane are added to a reaction vessel, and 0.9% of the total mass of 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxy-phenol and γ-aminopropyltriethoxysilane are added as a catalyst. The mixture is heated to 88°C under nitrogen protection and stirred for 3.2 h. After the reaction is completed, it is cooled to room temperature, and low-boiling substances are removed by vacuum distillation. Then, it is dried in a vacuum drying oven at 80°C for 4 h to obtain the modified ultraviolet absorber.

[0043] The preparation method of the mercapto-styrene-methacrylate copolymer is the same as in Example 1.

[0044] The preparation method of the hyperbranched polyester-polysiloxane block copolymer is the same as in Example 1.

[0045] The preparation method of this junction box material includes the following steps: The raw materials for the junction box material were put into a high-speed mixer and mixed (mixed at 780 rpm for 25 min) to obtain mixture A; Mixture A is fed into a twin-screw extruder for melting and extrusion to obtain mixture B. The main feed rate is 29 kg / h, and the temperature of each zone of the twin-screw extruder is set as follows: Zone 1 155℃, Zone 2 278℃, Zone 3 292℃, Zones 4 to 10 292℃, Die 302℃, Screw speed 450 rpm, Vacuum degree -0.075 MPa. Mixture B is cooled by water at 40°C and then granulated by a pelletizer to obtain junction box material.

[0046] Comparative Example 1 A junction box material differs from Example 1 in that it uses unmodified carbon fiber instead of modified carbon fiber. Otherwise, it is the same as Example 1.

[0047] Comparative Example 2 A junction box material differs from Example 1 in that it uses 2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5-hexyloxyphenol (unmodified) instead of the modified UV absorber. Otherwise, it is the same as Example 1.

[0048] Comparative Example 3 A junction box material differs from Example 1 in that the compatibilizer is a styrene-methacrylate copolymer that does not contain thiol groups. Everything else is the same as in Example 1.

[0049] Comparative Example 4 A junction box material, differing from Example 1 in that it does not contain insulating filler (tourmaline powder). Otherwise, it is the same as Example 1.

[0050] Comparative Example 5 A junction box material differs from Example 1 in that the composite grout contains only bisphenol A epoxy resin and does not contain γ-glycidoxypropyltrimethoxysilane. Everything else is the same as in Example 1.

[0051] Comparative Example 6 A junction box material differs from Example 1 in that the raw material contains 60 parts by weight of PPE resin and 15 parts by weight of PPS resin. Everything else is the same as in Example 1.

[0052] Comparative Example 7 A junction box material differs from Example 1 in that the raw material contains 30 parts by weight of PPE resin and 45 parts by weight of PPS resin. Everything else is the same as in Example 1.

[0053] Effect test experiment The products obtained in Examples 1-4 and Comparative Examples 1-7 were subjected to performance tests, and the relevant test methods are as follows: Impact strength: Tested according to GB / T 1043.1-2008; Thermal conductivity: as per GB / T 10297-2015; Tracking index: conducted according to GB / T 4207-2022; Weather resistance: Tested according to GB / T 16422.3-2022, yellowing index after 2000h xenon lamp aging; Heat distortion temperature: in accordance with GB / T 1634.2-2019, with a static bending stress of 0.45 MPa applied; Tensile strength: tested in accordance with GB / T 1040.2-2022.

[0054] The test results are shown in Table 1.

[0055] Table 1 Referring to the data in Table 1, compared with Examples 1-4, Comparative Example 1, due to the use of unmodified carbon fiber and the absence of composite slurry coating treatment, experienced a significant decrease in the interfacial bonding force between the carbon fiber and the resin matrix. This not only prevented the full utilization of the mechanical reinforcement effect of the carbon fiber but also disrupted the continuity of the thermal conductivity pathway. Ultimately, the impact strength and thermal conductivity were significantly inferior to those of the other examples, fully demonstrating that composite slurry coating modification of the carbon fiber surface is crucial for ensuring the mechanical and heat dissipation performance of the material. Comparative Example 2 used an unmodified UV absorber without silane coupling agent modification treatment. Due to the poor compatibility of small-molecule UV absorbers in the non-polar PPE / PPS system, they are prone to migration and loss during long-term use, resulting in a sharp decline in the weather resistance of the material after xenon lamp aging, with a yellowing index far exceeding that of the other examples. In contrast, the silane-modified UV absorber in the examples was chemically bonded tightly to the system, effectively solving the migration problem and ensuring long-term weather resistance. Comparative Example 3 used a thiol-free ordinary styrene-methacrylate copolymer as a compatibilizer, which could not achieve stable bonding with the modified UV absorber. It also failed to optimize the interfacial compatibility between PPE and PPS, as well as between the fillers, leading to uneven dispersion of the internal components and a comprehensive decrease in impact strength and thermal conductivity. Comparison of the various examples shows that thiol-containing compatibilizers are the core components for improving system compatibility and ensuring balanced overall material performance. Comparative Example 4, due to the lack of insulating filler, resulted in a significant reduction in the dielectric strength and tracking index of the material, failing to meet the electrical safety requirements of the junction box. In contrast, the insulating filler added in the examples enhanced insulation performance through synergistic effects, ensuring the electrical safety of the material. Comparative Example 5's composite slurry contained only bisphenol A epoxy resin without any silane coupling agent. Although it could form a coating layer on the carbon fiber surface, it could not further enhance the compatibility with the resin matrix through the functional groups of silane, resulting in insufficient interfacial bonding between the carbon fiber and the matrix. Ultimately, this manifested as lower impact strength and thermal conductivity than in the other examples, verifying the necessity of combining epoxy resin and silane coupling agent in the composite slurry. Comparative Example 6 had an imbalance in the PPE to PPS ratio, with excessive PPE and insufficient PPS. Due to the high melt viscosity of PPE itself and the lack of sufficient PPS to adjust compatibility and flowability, the melt flow rate of the material dropped sharply, resulting in poor processing adaptability and a decrease in impact strength. In contrast, the reasonable ratio of PPE to PPS in the examples ensured both the high temperature resistance and rigidity of the material and optimized processing flowability through synergistic effects. Comparative Example 7, due to excessive PPS and insufficient PPE, weakened the material's rigidity and high-temperature resistance, resulting in lower tensile strength and heat distortion temperature compared to the other examples. This further demonstrates that the scientific ratio of PPE to PPS is key to balancing the material's rigidity, high-temperature resistance, and processing performance.

[0056] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention.

Claims

1. A junction box material, characterized in that, The raw materials, by weight, include: 40-55 parts PPE resin, 25-35 parts PPS resin, 8-12 parts modified carbon fiber, 2-5 parts insulating filler, 3-8 parts compatibilizer, 0.5-2 parts modified UV absorber, 3-5 parts flow improver, 1-2 parts antioxidant, and 1.5-3 parts lubricant. The modified carbon fiber is obtained by coating the surface of carbon fiber with a composite slurry, which is obtained by mixing bisphenol A epoxy resin and γ-glycidoxypropyltrimethoxysilane. The compatibilizer contains thiol groups; The modified ultraviolet absorber is obtained by modifying an ultraviolet absorber with a silane coupling agent.

2. The junction box material according to claim 1, characterized in that, The method for preparing the modified carbon fiber includes the following steps: The carbon fiber is impregnated in a composite slurry for 10-15 minutes and then dried to obtain the modified carbon fiber. The composite slurry is obtained by mixing the bisphenol A epoxy resin and the γ-glycidoxypropyltrimethoxysilane in a mass ratio of (3-5):

1.

3. The junction box material according to claim 1, characterized in that, The ultraviolet absorber is one of 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxyphenol, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, 2-hydroxy-4-n-octyloxybenzophenone, and o-hydroxybenzoate; the silane coupling agent is one of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, and γ-mercaptopropyltrimethoxysilane.

4. The junction box material according to claim 3, characterized in that, The modified UV absorber is obtained by ring-opening addition reaction of 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxyphenol and γ-aminopropyltriethoxysilane in a molar ratio of 1:(0.01-0.02).

5. The junction box material according to claim 1, characterized in that, The compatibilizer is a mercapto-styrene-methacrylate copolymer.

6. The junction box material according to claim 1, characterized in that, The insulating filler is at least one of tourmaline powder, α-alumina, fumed silica, and boron nitride.

7. The junction box material according to claim 1, characterized in that, The flowability improver is a hyperbranched polyester-polysiloxane block copolymer.

8. The junction box material according to claim 1, characterized in that, The antioxidant is at least one of antioxidant 1010, antioxidant 168, antioxidant 245 and antioxidant 1076.

9. The junction box material according to claim 1, characterized in that, The lubricant is at least one of pentaerythritol tetrastearate, silicone powder, polyethylene wax, and ethylene bis-stearamide.

10. A method for preparing a junction box material as described in any one of claims 1 to 9, characterized in that, Includes the following steps: The raw materials are mixed, melted, extruded, and granulated to obtain the junction box material.

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