High-weather-resistant flame-retardant PC (polycarbonate) and ASA (acrylonitrile-styrene-acrylate) outdoor electric appliance material and preparation method thereof

Abstract

The invention relates to the technical field of high polymer materials, in particular to a high-weather-resistant flame-retardant PC + ASA outdoor electric appliance material and a preparation method thereof. The high-weather-resistant flame-retardant PC + ASA outdoor electric appliance material is prepared from the following raw materials in parts by mass: 50 to 60 parts of polycarbonate (PC), 30 to 40 parts of acrylonitrile-styrene-acrylate copolymer (ASA), 0.5 to 1 part of ultraviolet light absorber, 10 to 18 parts of halogen-free flame retardant, 0.3 to 0.5 part of light stabilizer, 0.2 to 0.3 part of antioxidant, 0.5 to 1 part of lubricant and 8 to 10 parts of modified nano silicon carbide. The PC + ASA composite material prepared through component collaborative design and interface functional modification has excellent weather resistance, flame retardance and mechanical properties, and the material provides a high-performance and long-life solution for the fields of outdoor electric appliances, new energy equipment and the like.

Description

Technical Field

[0001] The present application relates to the technical field of polymer materials, and in particular to a highly weather-resistant and flame-retardant PC+ASA outdoor electrical material and a preparation method thereof. Background Art

[0002] Currently, the housings of outdoor electrical appliances are mostly made of single polymers or general-purpose composite materials, such as polycarbonate (PC) and acrylonitrile-styrene-acrylate copolymer (ASA). These materials have the following problems: 1) Insufficient weather resistance: They are prone to aging under long-term UV exposure, resulting in a decrease in mechanical properties. 2) Flame retardancy defects: Traditional flame retardants (such as halogen-based ones) are environmentally friendly, while halogen-free flame retardants tend to reduce the mechanical properties of the material. Existing materials are prone to aging under long-term UV exposure, and the added flame retardants have a negative impact on the mechanical properties of the material, especially the lack of stability and mechanical properties in extreme outdoor environments. Summary of the Invention

[0003] The purpose of this application is to address the shortcomings of current technology and provide a highly weather-resistant and flame-retardant PC+ASA outdoor electrical material and a preparation method thereof. The highly weather-resistant and flame-retardant PC+ASA outdoor electrical material prepared in this application has excellent weather resistance, flame retardancy, wear resistance and mechanical properties, and is suitable for use as a composite material in scenarios such as outdoor electrical appliance housings and solar panel frames.

[0004] In the first aspect, the present application provides a highly weather-resistant and flame-retardant PC+ASA outdoor electrical material, which adopts the following technical solution: a highly weather-resistant and flame-retardant PC+ASA outdoor electrical material, which comprises the following raw materials in parts by mass: 50-60 parts of polycarbonate (PC), 30-40 parts of acrylonitrile-styrene-acrylate copolymer (ASA), 0.5-1 part of ultraviolet absorber, 10-18 parts of halogen-free flame retardant, 0.3-0.5 part of light stabilizer, 0.2-0.3 part of antioxidant, 0.5-1 part of lubricant, and also includes 8-10 parts of modified nano-silicon carbide.

[0005] By adopting the above technical solution, polycarbonate (PC) is used as the matrix material to provide the material with mechanical strength and toughness. At the same time, PC has good weather resistance and processing properties. Acrylonitrile-styrene-acrylate copolymer (ASA) increases the material's weather resistance and chemical resistance, while also improving the material's UV resistance. Ultraviolet absorbers: For example, the combination of ultraviolet absorber UV-326 and high-efficiency ultraviolet absorbers can effectively absorb, reflect and scatter ultraviolet rays, protecting the material from damage by ultraviolet rays. Halogen-free flame retardants: For example, halogen-free flame retardants are composed of bisphenol A bis(diphenyl phosphate) and modified carbon nanotube weather-resistant flame retardants. Modified carbon nanotube weather-resistant flame retardants have excellent mechanical properties, thermal stability and flame retardant effects, as well as good resistance to ultraviolet aging. Light stabilizers help protect the material from the effects of light aging and extend the material's service life. Antioxidants help prevent the material from degradation due to oxidation during long-term use. Lubricants help improve the material's processing properties and surface smoothness. Modified nano-silicon carbide, through its coating with aminopropyl polymethylphenylsiloxane and scattering by carvacrol, enhances the material's mechanical and weathering properties. Furthermore, the presence of Ag+ metal ions enhances the material's UV resistance. The synergistic effect of these components results in the highly weatherable and flame-retardant PC+ASA outdoor electrical appliance material possessing excellent weather resistance, flame retardancy, wear resistance, and mechanical properties. Specifically, the modified carbon nanotube weathering flame retardant exhibits excellent compatibility with PC, enhancing the material's flame retardancy and weather resistance. The UV absorber and light stabilizer work together to effectively protect the material from UV damage. The halogen-free flame retardant provides the necessary flame retardancy while avoiding potential environmental hazards. Modified nano-silicon carbide enhances the material's mechanical strength and weather resistance, while also improving its UV resistance. In summary, the synergistic effect of these components enhances the material's overall performance, making it suitable for applications such as outdoor appliance housings and solar panel frames.

[0006] Preferably, the halogen-free flame retardant is composed of bisphenol A bis(diphenyl phosphate) and modified carbon nanotube weather-resistant flame retardant in a mass ratio of 3:3-5.

[0007] By adopting the above technical solution, bisphenol A bis(diphenyl phosphate) can inhibit the generation and transfer of free radicals during the combustion process by releasing phosphate gas, thereby exerting a flame retardant effect. The modified carbon nanotube weathering flame retardant enhances the flame retardant properties of the material through its excellent mechanical properties and thermal stability. At the same time, the benzotriazole groups and phenylphosphinic acid groups on the surface of the carbon nanotubes have a synergistic flame retardant effect. The modified carbon nanotube weathering flame retardant has excellent resistance to UV aging and can effectively protect the material from damage by ultraviolet rays. The modified carbon nanotube weathering flame retardant has good compatibility with polycarbonate (PC). The carboxyl groups on the surface of the carbon nanotubes can undergo esterification reaction with the terminal hydroxyl groups of PC and have similar compatibility with the ester groups in the PC molecular chain, greatly improving the compatibility of the carbon nanotubes with PC. The synergistic effect between the modified carbon nanotube weathering flame retardant and bisphenol A bis(diphenyl phosphate) is mainly reflected in the improvement of flame retardant properties. The high thermal conductivity of carbon nanotubes and the flame-retardant gas release of phosphate esters complement each other to form a more effective flame retardant mechanism. At the same time, the weather resistance of carbon nanotubes and the chemical stability of phosphate esters can jointly improve the material's weather resistance. In summary, the bisphenol A bis(diphenyl phosphate) in the halogen-free flame retardant and the modified carbon nanotube weather-resistant flame retardant, through their respective functional properties and mutual synergy, jointly enhance the material's flame retardancy and weather resistance, making it more suitable for use in scenarios such as outdoor appliance housings and solar panel frames.

[0008] Preferably, the preparation method of the modified carbon nanotube weather-resistant flame retardant comprises the following steps: S41. Dry one part of carbon nanotube powder by mole in an oven at 50° C. for 30-40 minutes, then place it in a plasma equipment reactor. After evacuating the reactor, introduce a mixture of ammonia and nitrogen in a volume ratio of 6:1 until the pressure in the reactor is saturated. Turn on the equipment to generate ammonia and nitrogen plasma to treat the carbon nanotube powder. The treatment power is 600-800 W, the treatment time is 20-30 minutes, and the treatment pressure is 1-5 Pa. After cooling, amino-modified carbon nanotubes are obtained. S42. Add 1 part of amino-treated carbon nanotubes to 50 parts of deionized water at 50° C. and ultrasonically disperse for 30-40 minutes, add 0.5 parts of glacial acetic acid and stir evenly, then add 0.1 parts of benzotriazole, heat to 75-80° C. and stir to dissolve to obtain a mixed solution; let the mixed solution stand at room temperature for 4-6 hours, cool and filter, wash three times with deionized water, freeze-dry at -50° C. for 12 hours, and grind to obtain carbon nanotube powder containing benzotriazole groups; S43. Dissolve 1 part of phenylphosphinic acid in 100 parts of deionized water according to molar fractions, slowly add the carbon nanotube powder containing benzotriazole groups prepared in step S42 to the aqueous solution of phenylphosphinic acid, ultrasonically mix for 40-50 minutes, then freeze-dry at -50°C for 12 hours, and grind into powder to obtain a modified carbon nanotube weather-resistant flame retardant.

[0009] By adopting the above technical solution, a modified carbon nanotube weathering flame retardant is prepared using carbon nanotubes as a matrix and benzotriazole and phenylphosphinic acid as functional groups. The carbon nanotubes have excellent mechanical properties and good thermal stability, as well as good flame retardancy and resistance to UV aging. An amino group and a nitrogen atom hybrid structure are introduced onto the surface of the carbon nanotubes through an ammonia / nitrogen plasma. Benzotriazole groups are introduced onto the surface of the carbon nanotubes through a reaction between benzotriazole and amino groups, imparting UV aging resistance. Phenylphosphinic acid groups are introduced onto the surface of the carbon nanotubes through physical adsorption via π-π interactions and chemical reactions between amino groups and phosphinic acid groups. The phenylphosphinic acid groups and the nitrogen atom heterocycle introduced during plasma treatment have a synergistic flame retardant effect. The carboxyl groups on the surface of carbon nanotubes can undergo esterification reaction with the terminal hydroxyl groups of polycarbonate, and at the same time have similar compatibility with the ester groups in the polycarbonate molecular chain. The large conjugated system contained in the carbon nanotubes themselves can undergo π-π interaction with the benzene rings in polycarbonate, greatly improving the compatibility of carbon nanotubes and polycarbonate and playing a good compatibilization role.

[0010] Preferably, the ultraviolet absorber is composed of ultraviolet absorber UV-326 and high-efficiency ultraviolet absorber in a mass ratio of 3:5.

[0011] By employing the above-mentioned technical solution, UV-326 can effectively absorb the UVB and UVA components of ultraviolet radiation, reducing direct UV radiation on materials. High-efficiency UV absorbers have higher UV absorption efficiency and a wider absorption spectrum, covering more UV wavelengths and providing more comprehensive protection. UV-326 and high-efficiency UV absorbers complement each other to absorb insufficient UV radiation, improving overall UV absorption efficiency. The synergistic effect of UV-326 and high-efficiency UV absorbers can enhance the material's resistance to light aging and extend its service life. High-efficiency UV absorbers: In addition to absorbing UV radiation, high-efficiency UV absorbers may also scatter and reflect UV radiation, further reducing its impact on materials. UV-326 and high-efficiency UV absorbers work together to form multiple protective layers, blocking UV damage from different angles. The synergistic effect of UV-326 and high-efficiency UV absorbers creates a more stable protective mechanism, enhancing the material's UV protection. In summary, the synergistic effect of UV-326 and high-efficiency UV absorbers can significantly enhance the UV protection capabilities of PC+ASA outdoor electrical materials, reduce the impact of UV rays on material properties, and extend the material's service life. This synergistic effect also helps maintain the stability of the material's color and properties.

[0012] Preferably, the preparation method of the high-efficiency ultraviolet absorber comprises the following steps: S61. Dissolve 31.6 parts of 3-(3-hydroxy-3-methylbutane)-2,4,6-trihydroxybenzophenone in 350 parts of acetone by mass. Add 0.4 parts of dibutyltin dilaurate under a nitrogen atmosphere. Heat to 90° C. and gradually add dropwise 36 parts of 1-allyl-3-chloro-5-fluorobenzene. The addition time is controlled to 3 hours. After the addition is completed, the mixture is kept at a constant temperature for 80-90 minutes to obtain a reaction product. S62. Add 400 parts of ethanol to the reaction product to dissolve the remaining unreacted substances, filter to obtain a solid, wash the filtered product with anhydrous ethanol three times, and dry it to obtain a high-efficiency ultraviolet absorber.

[0013] By adopting the above technical solution, step S61: chemical synthesis reaction, 3-(3-hydroxy-3-methylbutanyl)-2,4,6-trihydroxybenzophenone is used as the core UV-absorbing group, with a polyhydroxy structure that enhances UV absorption capacity. 1-Allyl-3-chloro-5-fluorobenzene is combined with a benzophenone derivative through nucleophilic substitution or addition reaction, introducing allyl, chlorine, and fluorine substituents to enhance molecular stability and UV absorption range. Dibutyltin dilaurate is used as a catalyst to promote efficient reaction. Heating to 90°C under nitrogen protection prevents oxidative side reactions. The dropwise addition time is 3 hours to ensure uniform reaction, and the cross-linking or substitution reaction is completed at a constant temperature for 80-90 minutes. Step S62: purification and post-processing, unreacted raw materials and by-products are dissolved in ethanol and filtered to obtain a high-purity solid product. Residual impurities are removed by washing with anhydrous ethanol, and after drying, a high-efficiency UV absorber powder is obtained, ensuring its thermal stability and dispersibility. The role of the prepared high-efficiency UV absorber in this application: 1. Ultraviolet absorption and protection, absorbing medium-wave (UVB, 280-315nm) and long-wave (UVA, 315-400nm) ultraviolet rays through the conjugated structure of the benzophenone skeleton, covering a wider wavelength range. Chemical modification enhances performance: 1) Fluorine and chlorine substituents: enhance ultraviolet absorption efficiency through electronic effects and extend molecular life. 2) Allyl group: improves the compatibility of the molecule with the PC / ASA matrix and reduces migration and precipitation. 2. Light stability and durability, resisting photodegradation through intramolecular hydrogen bonds and rigid structures, maintaining the color and mechanical properties of the material for a long time. 3. Synergistic enhancement mechanism, complementary to UV-326: UV-326: mainly targets the UVB band (280-315nm), absorbing free radicals through hydroxyl groups. High-efficiency UV absorber: covers the UVA band (315-400nm) and part of visible light, scattering / reflecting ultraviolet rays through conjugated systems and substituents. Together, they form a multi-layered "absorption-reflection-scattering" protective layer, significantly reducing UV penetration. This slows photooxidation, reduces PC / ASA molecular chain breakage, and extends the material's outdoor life. Together, the high-efficiency UV absorber and UV-326 form a multi-dimensional protective network, significantly enhancing the material's weather resistance and mechanical properties, meeting the demands of demanding applications such as outdoor appliance housings and solar panel frames.

[0014] Preferably, the antioxidant is antioxidant 1010; and the lubricant is zinc stearate or calcium stearate.

[0015] Preferably, the light stabilizer is hindered amine light stabilizer 944.

[0016] Preferably, the preparation method of the modified nano-silicon carbide comprises the following steps: S91. Add 10 parts by mass of nano-silicon carbide with a particle size of 20-50 nm to 100 parts by mass of deionized water and disperse them evenly to obtain a dispersion. The dispersion is heated to 85-90° C. and the pH of the dispersion is adjusted to 9-10 with a 10% aqueous sodium hydroxide solution. Five parts of an ethanol solution of orthosilicate with a mass concentration of 25% are slowly added dropwise to the dispersion over 1 hour to carry out a sol-gel reaction for 3 hours. The mixture is then filtered, washed three times with anhydrous ethanol, and dried to obtain coated nano-silicon carbide. S92, adding 10 parts by mass of the coated nano-silicon carbide to 30 parts by mass of a 75% ethanol aqueous solution, adjusting the pH to 4-5, adding 0.5 parts of N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane, stirring and reacting for 1-2 hours, filtering, washing with water, and drying to obtain silane-modified nano-silicon carbide; S93. According to the mass fractions, 30 parts of dimethylformamide solution with a mass concentration of 2% trifluoroacetic anhydride are added and heated to 90°C, 10 parts of silane-modified nano-silicon carbide are added, and the pH of the dispersion is adjusted to 9-10 with a mass concentration of 15% sodium hydroxide aqueous solution. The mixture is reacted at a constant temperature for 3-4 hours, filtered, washed with water, and dried to obtain modified nano-silicon carbide.

[0017] By adopting the above technical solution, a silicon dioxide layer is first deposited on the surface of nano-silicon carbide through a sol-gel method to provide sufficient active sites for modification. Then, amino groups are introduced into the surface of nano-silicon carbide through the reaction of N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane with the silanol groups on the surface of silicon dioxide. Subsequently, trifluoromethyl groups are introduced through the acylation reaction of trifluoroacetic anhydride with some of the amino groups, giving the nano-silicon carbide hydrophobic properties. By adding nano-silicon carbide containing amino and fluorine-containing groups on the surface, the wear resistance of outdoor electrical materials is improved. The fluorine-containing groups extend outward to form a hydrophobic layer, which can improve the waterproof performance of outdoor electrical materials.

[0018] In a second aspect, the present application provides a method for preparing a highly weather-resistant and flame-retardant PC+ASA outdoor electrical material, which adopts the following technical solution: As a general technical concept, the present application also provides a method for preparing the above-mentioned highly weather-resistant and flame-retardant PC+ASA outdoor electrical appliance material, comprising the following steps: S101. Add all the raw materials in the formula into a high-speed mixer according to their mass fractions and premix for 40-50 minutes to obtain a mixture; S102. Feed the mixture into a twin-screw extruder through an automatic feeding system for melt extrusion and granulation to obtain a highly weather-resistant and flame-retardant PC+ASA outdoor electrical material, wherein the screw speed of the twin-screw extruder is 250-300 rpm and the temperature is 230-250°C.

[0019] In summary, the beneficial technical effects of this application are: 1.Excellent weather resistance 1) Ultraviolet protection system: UV-326 and high-efficiency ultraviolet absorbers work together to effectively block ultraviolet penetration. + Scattering: Scattering of UV light through the plasma resonance effect. Carbon nanotubes absorb UV energy and convert it into heat.

[0020] 2) Anti-heat and humidity aging: Antioxidants and light stabilizers synergistically inhibit free radical chain reactions.

[0021] 2. High efficiency flame retardant performance Halogen-free flame retardant synergistic mechanism: Bisphenol A bis(diphenyl phosphate): Inhibits combustion through both vapor-phase and condensed-phase flame retardancy. Modified carbon nanotube weathering flame retardant: Physically blocks oxygen and heat diffusion while simultaneously catalyzing carbonization to form a dense carbon layer. Bisphenol A phosphate and carbon nanotubes synergistically promote carbon layer formation.

[0022] 3.Excellent mechanical properties 1) Enhanced wear resistance: Modified nano-silicon carbide improves the wear resistance of outdoor electrical materials by adding nano-silicon carbide containing amino and fluorine-containing groups on the surface. The fluorine-containing groups extend outward to form a hydrophobic layer, which can improve the waterproof performance of outdoor electrical materials.

[0023] 2) Interface compatibility optimization: chemical bonding and physical adsorption of modified nano-silicon carbide to the substrate improve interface bonding.

[0024] 4. Environmental protection and processing performance 1) Halogen-free and environmentally friendly design: Halogen-free flame retardants are used to avoid the release of toxic gases.

[0025] 2) Processing performance optimization: Lubricants reduce melt viscosity, and modified nano-silicon carbide and carbon nanotubes are evenly dispersed to improve processing efficiency. DETAILED DESCRIPTION

[0026] The embodiments of the present application will be described in detail below with reference to the examples, but it will be understood by those skilled in the art that the following examples are merely illustrative of the present application and should not be considered as limiting the scope of the present application. In the examples, if specific conditions are not specified, the conditions are carried out according to conventional conditions or manufacturer recommendations. The reagents or instruments used are not specified by the manufacturer and are conventional products that can be purchased commercially.

[0027] In the following Examples and Preparation Examples, 1 part by mass means 100 g, and 1 part by mole means 1 mol.

[0028] Preparation Example 1 Preparation of modified carbon nanotube weather-resistant flame retardant The preparation method of the modified carbon nanotube weather-resistant flame retardant comprises the following steps: S41. Drying one part of carbon nanotube powder in an oven at 50° C. for 35 minutes by mole fraction, placing the powder in a plasma equipment reactor, evacuating the reactor, and introducing a mixture of ammonia and nitrogen in a volume ratio of 6:1 until the reactor is saturated with pressure. Turning on the equipment to generate ammonia and nitrogen plasma to treat the carbon nanotube powder at a processing power of 700 W, a processing time of 25 minutes, and a processing pressure of 3 Pa. After cooling, amino-modified carbon nanotubes are obtained. S42. Add 1 part of amino-treated carbon nanotubes to 50 parts of deionized water at 50° C. and ultrasonically disperse for 35 minutes, add 0.5 parts of glacial acetic acid and stir evenly, then add 0.1 parts of benzotriazole, heat to 77° C. and stir to dissolve to obtain a mixed solution; let the mixed solution stand at room temperature for 5 hours, cool and filter, wash three times with deionized water, freeze-dry at -50° C. for 12 hours, and grind to obtain carbon nanotube powder containing benzotriazole groups; S43. Dissolve 1 part of phenylphosphinic acid in 100 parts of deionized water according to molar fractions, slowly add the carbon nanotube powder containing benzotriazole groups prepared in step S42 to the aqueous solution of phenylphosphinic acid, ultrasonically mix for 45 minutes, then freeze-dry at -50°C for 12 hours, and grind into powder to obtain a modified carbon nanotube weather-resistant flame retardant.

[0029] Preparation Example 2 Preparation of High-Efficiency UV Absorber The preparation method of a high-efficiency ultraviolet absorber comprises the following steps: S61. Dissolve 31.6 parts of 3-(3-hydroxy-3-methylbutane)-2,4,6-trihydroxybenzophenone in 350 parts of acetone by mass. Add 0.4 parts of dibutyltin dilaurate under a nitrogen atmosphere. Heat to 90° C. and gradually add dropwise 36 parts of 1-allyl-3-chloro-5-fluorobenzene. The addition time is controlled to 3 hours. After the addition is completed, the mixture is kept at a constant temperature for 85 minutes to obtain a reaction product. S62. Add 400 parts of ethanol to the reaction product to dissolve the remaining unreacted substances, filter to obtain a solid, wash the filtered product with anhydrous ethanol three times, and dry it to obtain a high-efficiency ultraviolet absorber.

[0030] Preparation Example 3 Preparation of modified nano-silicon carbide The preparation method of modified nano-silicon carbide comprises the following steps: S91. Add 10 parts by mass of nano-silicon carbide with a particle size of 20-50 nm to 100 parts by mass of deionized water and disperse them evenly to obtain a dispersion. The dispersion is heated to 86° C. and the pH of the dispersion is adjusted to 9 with a 10% aqueous sodium hydroxide solution. Five parts of an ethanol solution of orthosilicate with a mass concentration of 25% is slowly added dropwise to the dispersion over 1 hour to carry out a sol-gel reaction for 3 hours. The mixture is then filtered, washed three times with anhydrous ethanol, and dried to obtain coated nano-silicon carbide. S92, adding 10 parts by mass of the coated nano-silicon carbide to 30 parts by mass of a 75% ethanol aqueous solution, adjusting the pH to 4.5, adding 0.5 parts of N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane, stirring and reacting for 2 hours, filtering, washing with water, and drying to obtain silane-modified nano-silicon carbide; S93. According to the mass fractions, 30 parts of a 2% trifluoroacetic anhydride solution in dimethylformamide were heated to 90°C, 10 parts of silane-modified nano-silicon carbide were added, and the pH of the dispersion was adjusted to 10 with a 15% sodium hydroxide aqueous solution. The mixture was reacted at a constant temperature for 3.4 hours, filtered, washed with water, and dried to obtain modified nano-silicon carbide.

[0031] Example 1 A highly weather-resistant and flame-retardant PC+ASA outdoor electrical material, comprising the following raw materials, calculated by weight: 55 parts of polycarbonate (PC), 35 parts of acrylonitrile-styrene-acrylate copolymer (ASA), 0.8 parts of a UV absorber, 14 parts of a halogen-free flame retardant, 0.4 parts of a hindered amine light stabilizer 944, 0.25 parts of an antioxidant 1010, and 0.7 parts of zinc stearate, wherein the halogen-free flame retardant comprises bisphenol A bis(diphenyl phosphate) and a modified carbon nanotube weather-resistant flame retardant in a weight ratio of 3:4, and the UV absorber comprises a UV absorber UV-326 and a high-efficiency UV absorber in a weight ratio of 3:5. The preparation method of the above-mentioned highly weather-resistant and flame-retardant PC+ASA outdoor electrical appliance material comprises the following steps: S101, adding each raw material in the formula according to the mass fraction into a high-speed mixer and premixing for 45 minutes to obtain a mixture; S102. The mixed material is fed into a twin-screw extruder through an automatic feeding system for melt extrusion and granulation to obtain a highly weather-resistant and flame-retardant PC+ASA outdoor electrical material, wherein the screw speed of the twin-screw extruder is 280 rpm and the temperature is 240° C.

[0032] Example 2 A highly weather-resistant and flame-retardant PC+ASA outdoor electrical material comprises the following raw materials, calculated by weight: 50 parts of polycarbonate (PC), 30 parts of acrylonitrile-styrene-acrylate copolymer (ASA), 0.5 parts of a UV absorber, 10 parts of a halogen-free flame retardant, 0.3 parts of a hindered amine light stabilizer 944, 0.2 parts of an antioxidant 1010, 0.5 parts of zinc stearate, and 8 parts of modified nano-silicon carbide, wherein the halogen-free flame retardant comprises bisphenol A bis(diphenyl phosphate) and a modified carbon nanotube weather-resistant flame retardant in a weight ratio of 3:3, and the UV absorber comprises a UV absorber UV-326 and a high-efficiency UV absorber in a weight ratio of 3:5. The preparation method of the above-mentioned highly weather-resistant and flame-retardant PC+ASA outdoor electrical appliance material comprises the following steps: S101, adding the raw materials in the formula according to the mass parts into a high-speed mixer and premixing for 40 minutes to obtain a mixture; S102. The mixed material is fed into a twin-screw extruder through an automatic feeding system for melt extrusion and granulation to obtain a highly weather-resistant and flame-retardant PC+ASA outdoor electrical material, wherein the screw speed of the twin-screw extruder is 250 rpm and the temperature is 230° C.

[0033] Example 3 A highly weather-resistant and flame-retardant PC+ASA outdoor electrical material comprises the following raw materials, calculated by weight: 60 parts of polycarbonate (PC), 40 parts of acrylonitrile-styrene-acrylate copolymer (ASA), 1 part of a UV absorber, 18 parts of a halogen-free flame retardant, 0.5 parts of a hindered amine light stabilizer 944, 0.3 parts of an antioxidant 1010, 1 part of calcium stearate, and 10 parts of modified nano-silicon carbide, wherein the halogen-free flame retardant comprises bisphenol A bis(diphenyl phosphate) and a modified carbon nanotube weather-resistant flame retardant in a weight ratio of 3:5, and the UV absorber comprises a UV absorber UV-326 and a high-efficiency UV absorber in a weight ratio of 3:5. The preparation method of the above-mentioned highly weather-resistant and flame-retardant PC+ASA outdoor electrical appliance material comprises the following steps: S101, adding the raw materials in the formula according to the mass parts into a high-speed mixer and premixing for 50 minutes to obtain a mixture; S102. The mixed material is fed into a twin-screw extruder through an automatic feeding system for melt extrusion and granulation to obtain a highly weather-resistant and flame-retardant PC+ASA outdoor electrical material, wherein the screw speed of the twin-screw extruder is 300 rpm and the temperature is 250° C.

[0034] Example 4 A highly weather-resistant and flame-retardant PC+ASA outdoor electrical material comprises the following raw materials, calculated by weight: 55 parts of polycarbonate (PC), 35 parts of acrylonitrile-styrene-acrylate copolymer (ASA), 0.8 parts of a UV absorber, 14 parts of a halogen-free flame retardant, 0.4 parts of a hindered amine light stabilizer 944, 0.25 parts of an antioxidant 1010, 0.7 parts of zinc stearate, and 9 parts of modified nano-silicon carbide, wherein the halogen-free flame retardant comprises bisphenol A bis(diphenyl phosphate) and a modified carbon nanotube weather-resistant flame retardant in a weight ratio of 3:4, and the UV absorber comprises a UV absorber UV-326 and a high-efficiency UV absorber in a weight ratio of 3:5. The preparation method of the above-mentioned highly weather-resistant and flame-retardant PC+ASA outdoor electrical appliance material comprises the following steps: S101, adding each raw material in the formula according to the mass fraction into a high-speed mixer and premixing for 45 minutes to obtain a mixture; S102. The mixed material is fed into a twin-screw extruder through an automatic feeding system for melt extrusion and granulation to obtain a highly weather-resistant and flame-retardant PC+ASA outdoor electrical material, wherein the screw speed of the twin-screw extruder is 270 rpm and the temperature is 240° C.

[0035] Comparative Example 1 The same as Example 4, except that unmodified nano-silicon carbide is used in equal parts by mass instead of modified nano-silicon carbide.

[0036] Comparative Example 2 The same as Example 4, except that the halogen-free flame retardant is bisphenol A bis(diphenyl phosphate).

[0037] Comparative Example 3 The same as Example 4, except that the halogen-free flame retardant is a modified carbon nanotube weather-resistant flame retardant.

[0038] Comparative Example 4 The same as Example 4, except that the ultraviolet absorber is ultraviolet absorber UV-326.

[0039] Comparative Example 5 The same as Example 4, except that the ultraviolet absorber is a high-efficiency ultraviolet absorber.

[0040] Performance Testing The highly weather-resistant and flame-retardant PC+ASA outdoor electrical appliance materials prepared in Examples 1 to 4 and Comparative Examples 1 to 5 were sampled and injection-molded into test bars. The following performance tests were performed. Three parallel samples were taken for each group, and the results were averaged. The test results are shown in Table 1. The tensile strength is tested according to ASTM D638, with a test temperature of 23°C and a tensile rate of 50 mm / min. Fluorescent UV lamp artificial accelerated aging is carried out in accordance with ISO 4892.3, using UVA340 lamp with an irradiance of 0.76W / (m2 at 340nm) 2 nm), black mark temperature 60±3℃, aging time 1000 hours; Tensile strength retention rate = tensile strength after 1000h UV aging test / tensile strength; Wear resistance test: According to EN 13329 standard, CS-10 grinding wheel, 500g load, test using Table abrasion tester, calculate the mass loss rate, the smaller the value, the more wear-resistant; Oxygen Index (LOI): Tested in accordance with ASTM D2863, the oxygen index (LOI) of the samples before and after 1000h UV aging was tested.

[0041] Table 1 Performance test Analyzing the data in Table 1, we can see that: 1) The highly weather-resistant and flame-retardant PC+ASA outdoor electrical appliance materials prepared in Examples 2-4 have excellent weather resistance, flame retardancy, wear resistance, and mechanical properties, making them suitable for composite materials used in scenarios such as outdoor electrical appliance housings and solar panel frames. The highly weather-resistant and flame-retardant PC+ASA outdoor electrical appliance material prepared in Example 1 has excellent weather resistance and flame retardancy.

[0042] 2) The performance comparison analysis of the highly weather-resistant and flame-retardant PC+ASA outdoor electrical material prepared in combination with Example 4 and Comparative Example 1 shows that the modified nano-silicon carbide prepared in this application first deposits a silicon dioxide layer on the surface of the nano-silicon carbide by a sol-gel method, providing sufficient active sites for modification. Then, by the reaction of N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane with the silanol group on the surface of silicon dioxide, an amino group is introduced into the surface of the nano-silicon carbide, followed by an acylation reaction of trifluoroacetic anhydride with part of the amino group to introduce a trifluoromethyl group, giving the nano-silicon carbide hydrophobic properties. By adding nano-silicon carbide containing amino and fluorine-containing groups on the surface, the wear resistance of the outdoor electrical material is improved. The fluorine-containing group extends outward to form a hydrophobic layer, which can improve the waterproof performance of the outdoor electrical material.

[0043] 3) A comparative analysis of the performance of the highly weather-resistant and flame-retardant PC+ASA outdoor electrical material prepared in combination with Example 4 and Comparative Examples 2-3 shows that the halogen-free flame retardant is composed of bisphenol A bis(diphenyl phosphate) and modified carbon nanotube weather-resistant flame retardant in a mass ratio of 3:4. The bisphenol A bis(diphenyl phosphate) and modified carbon nanotube weather-resistant flame retardant in the halogen-free flame retardant improve the flame retardant properties and weather resistance of the material through their respective functional properties and synergistic effects, making it more suitable for use in scenarios such as outdoor appliance housings and solar panel frames.

[0044] 4) A comparative analysis of the performance of the highly weather-resistant and flame-retardant PC+ASA outdoor electrical material prepared in combination with Example 4 and Comparative Examples 4-5 shows that the ultraviolet absorber is composed of ultraviolet absorber UV-326 and high-efficiency ultraviolet absorber in a mass ratio of 3:5. UV-326 can effectively absorb the UVB and UVA parts of ultraviolet rays, reducing the direct radiation of ultraviolet rays to the material. The high-efficiency ultraviolet absorber has a higher ultraviolet absorption efficiency and a wider absorption spectrum range, can cover more ultraviolet bands, and provide more comprehensive protection. UV-326 and the high-efficiency ultraviolet absorber can complement each other to absorb the insufficient part of ultraviolet rays and improve the overall ultraviolet absorption efficiency. The synergistic effect of UV-326 and the high-efficiency ultraviolet absorber can improve the anti-light aging performance of the material and extend the service life of the material. In summary, the synergistic effect of ultraviolet absorber UV-326 and the high-efficiency ultraviolet absorber can significantly improve the ultraviolet protection ability of PC+ASA outdoor electrical material, reduce the impact of ultraviolet rays on material performance, and extend the service life of the material.

[0045] The above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit the present application. Although the above embodiments provide a detailed description of the present application, relevant technical personnel should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modifications and equivalent replacements that do not depart from the spirit and scope of the present application should be included in the scope of protection of the present application.

Claims

1. A highly weather-resistant and flame-retardant PC+ASA outdoor electrical material, characterized in that: The preparation comprises the following raw materials in parts by mass: 50-60 parts of polycarbonate (PC), 30-40 parts of acrylonitrile-styrene-acrylate copolymer (ASA), 0.5-1 parts of ultraviolet absorber, 10-18 parts of halogen-free flame retardant, 0.3-0.5 parts of light stabilizer, 0.2-0.3 parts of antioxidant and 0.5-1 parts of lubricant.

2. The highly weather-resistant and flame-retardant PC+ASA outdoor electrical material according to claim 1, characterized in that: The invention also comprises 8-10 parts of modified nano silicon carbide.

3. The highly weather-resistant and flame-retardant PC+ASA outdoor electrical material according to claim 1, characterized in that: The halogen-free flame retardant is composed of bisphenol A bis(diphenyl phosphate) and modified carbon nanotube weather-resistant flame retardant in a mass ratio of 3:3-5.

4. The highly weather-resistant and flame-retardant PC+ASA outdoor electrical material according to claim 3, characterized in that: The preparation method of the modified carbon nanotube weather-resistant flame retardant comprises the following steps: S41. Dry one part of carbon nanotube powder by mole in an oven at 50° C. for 30-40 minutes, then place it in a plasma equipment reactor. After evacuating the reactor, introduce a mixture of ammonia and nitrogen in a volume ratio of 6:1 until the pressure in the reactor is saturated. Turn on the equipment to generate ammonia and nitrogen plasma to treat the carbon nanotube powder. The treatment power is 600-800 W, the treatment time is 20-30 minutes, and the treatment pressure is 1-5 Pa. After cooling, amino-modified carbon nanotubes are obtained. S42. Add 1 part of amino-treated carbon nanotubes to 50 parts of deionized water at 50° C. and ultrasonically disperse for 30-40 minutes, add 0.5 parts of glacial acetic acid and stir evenly, then add 0.1 parts of benzotriazole, heat to 75-80° C. and stir to dissolve to obtain a mixed solution; let the mixed solution stand at room temperature for 4-6 hours, cool and filter, wash three times with deionized water, freeze-dry at -50° C. for 12 hours, and grind to obtain carbon nanotube powder containing benzotriazole groups; S43. Dissolve 1 part of phenylphosphinic acid in 100 parts of deionized water according to molar fractions, slowly add the carbon nanotube powder containing benzotriazole groups prepared in step S42 to the aqueous solution of phenylphosphinic acid, ultrasonically mix for 40-50 minutes, then freeze-dry at -50°C for 12 hours, and grind into powder to obtain a modified carbon nanotube weather-resistant flame retardant.

5. The highly weather-resistant and flame-retardant PC+ASA outdoor electrical material according to claim 1, characterized in that: The ultraviolet absorber is composed of ultraviolet absorber UV-326 and high-efficiency ultraviolet absorber in a mass ratio of 3:

5.

6. The highly weather-resistant and flame-retardant PC+ASA outdoor electrical material according to claim 5, characterized in that: The preparation method of the high-efficiency ultraviolet absorber comprises the following steps: S61. Dissolve 31.6 parts of 3-(3-hydroxy-3-methylbutane)-2,4,6-trihydroxybenzophenone in 350 parts of acetone by mass. Add 0.4 parts of dibutyltin dilaurate under a nitrogen atmosphere. Heat to 90° C. and gradually add dropwise 36 parts of 1-allyl-3-chloro-5-fluorobenzene. Add dropwise for 3 hours. After the addition is complete, react at a constant temperature for 80-90 minutes to obtain a reaction product. S62. Add 400 parts of ethanol to the reaction product to dissolve the remaining unreacted substances, filter to obtain a solid, wash the filtered product with anhydrous ethanol three times, and dry it to obtain a high-efficiency ultraviolet absorber.

7. The highly weather-resistant and flame-retardant PC+ASA outdoor electrical material according to claim 1, characterized in that: The antioxidant is antioxidant 1010; the lubricant is zinc stearate or calcium stearate.

8. The highly weather-resistant and flame-retardant PC+ASA outdoor electrical material according to claim 1, characterized in that: The light stabilizer is hindered amine light stabilizer 944.

9. The highly weather-resistant and flame-retardant PC+ASA outdoor electrical material according to claim 2, characterized in that: The preparation method of the modified nano-silicon carbide comprises the following steps: S91. Add 10 parts by mass of nano-silicon carbide with a particle size of 20-50 nm to 100 parts by mass of deionized water and disperse them evenly to obtain a dispersion. The dispersion is heated to 85-90° C. and the pH of the dispersion is adjusted to 9-10 with a 10% aqueous sodium hydroxide solution. Five parts of an ethanol solution of orthosilicate with a mass concentration of 25% is slowly added dropwise to the dispersion over 1 hour to carry out a sol-gel reaction for 3 hours. The mixture is then filtered, washed three times with anhydrous ethanol, and dried to obtain coated nano-silicon carbide. S92, adding 10 parts by mass of the coated nano-silicon carbide to 30 parts by mass of a 75% ethanol aqueous solution, adjusting the pH to 4-5, adding 0.5 parts of N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane, stirring and reacting for 1-2 hours, filtering, washing with water, and drying to obtain silane-modified nano-silicon carbide; S93. According to the mass fractions, 30 parts of 2% trifluoroacetic anhydride dimethylformamide solution were heated to 90°C, 10 parts of silane-modified nano-silicon carbide were added, and the pH value of the dispersion was adjusted to 9-10 with 15% sodium hydroxide aqueous solution. The mixture was reacted at a constant temperature for 3-4 hours, filtered, washed with water, and dried to obtain modified nano-silicon carbide.

10. A method for preparing a highly weather-resistant and flame-retardant PC+ASA outdoor electrical appliance material according to any one of claims 1 to 9, characterized in that: The following steps are involved: S101, adding the raw materials in the formula according to the mass parts into a high-speed mixer and premixing for 40-50 minutes to obtain a mixture; S102. The mixed material is fed into a twin-screw extruder through an automatic feeding system for melt extrusion and granulation to obtain a highly weather-resistant and flame-retardant PC+ASA outdoor electrical material, wherein the screw speed of the twin-screw extruder is 250-300 rpm and the temperature is 230-250° C.

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