Halogen-free flame-retardant polyphenylene ether composite material for photovoltaics and preparation method thereof

Abstract

The present application relates to the field of high polymer composite material, in particular to a halogen-free flame-retardant polyphenyl ether composite material for photovoltaic and a preparation method thereof.The composite material has excellent melt strength, processing fluidity, flame retardancy, high temperature resistance, weather resistance, light aging resistance, and the surface of the shaped part is smooth.The composite material product has high stability, is especially suitable for extrusion molding of plate and profile with high appearance surface requirement, and can be widely applied to key devices required to have flame retardancy, light aging resistance, weather resistance and good appearance in the photovoltaic industry, such as junction boxes, supports and the like.

Description

Technical Field

[0001] This invention relates to the field of polymer composite materials, specifically to a halogen-free flame-retardant polyphenylene ether composite material for photovoltaic applications and its preparation method. Background Technology

[0002] Polyphenylene oxide (PPO) resin is an engineering plastic with excellent heat resistance, dimensional stability, and electrical insulation properties, widely used in electronics, automotive, and photovoltaic industries. However, PPO resin has drawbacks such as flammability and poor processing flowability, necessitating the addition of flame retardants and other modifiers to improve its performance. Traditionally, halogenated flame retardants (such as brominated flame retardants) have been widely used in PPO composites due to their highly efficient flame-retardant effects. However, these flame retardants release toxic gases during combustion, posing harm to the environment and human health, which is inconsistent with the current trend of green and environmentally friendly development.

[0003] Currently, various modified polyphenylene ether composite materials have been researched both domestically and internationally. CN110982245A discloses a modified polyphenylene ether resin material comprising polyphenylene ether resin, high-impact polystyrene, flame retardant, toughening agent, antioxidant, ultraviolet absorber, and carbon black masterbatch. This material can be used in photovoltaic junction box products and exhibits good low-temperature impact resistance and flame retardant properties. CN109553967A proposes a low-precipitation halogen-free flame-retardant polyphenylene ether-polyamide resin alloy. By adding halogen-free flame retardants, compatibilizers, and toughening agents, the material exhibits good flame retardant and mechanical properties in high-temperature and high-humidity environments. CN101880451B discloses a halogen-free flame-retardant polyphenylene ether composite, which consists of polyphenylene ether resin, polystyrene-based resin, toughening agent, and flame retardant. Its flame retardant performance reaches UL94V-0 level without dripping.

[0004] Furthermore, CN103265806A describes a method for preparing a flame-retardant glass fiber reinforced polyphenylene ether composite material. This method improves the mechanical properties of the material by adding glass fibers and reinforcing fibers, while simultaneously enhancing its flame-retardant properties by adding flame retardants. CN111560164A provides a high-toughness, weather-resistant, high-temperature resistant, halogen-free flame-retardant polyphenylene ether composite material. Through a specific formulation of compatibilizers, toughening agents, and halogen-free flame retardants, the toughness and weather resistance of the material are improved, making it suitable for photovoltaic connector housing materials.

[0005] However, existing halogen-free flame-retardant polyphenylene ether (PPE) composites still have some problems: First, most of the flame retardants used in conventional PPE resin formulations are brominated substances, which release a large amount of bromine-containing gas during combustion, posing a potential hazard to human health; second, the addition of flame retardants often reduces the mechanical properties and heat and oxygen resistance of the material, making it difficult to achieve a balance between high flame retardancy, excellent mechanical strength, and good heat and oxygen aging resistance; third, existing PPE composites still fall short of meeting the photovoltaic industry's requirements for heat resistance, aging resistance, UV resistance, and flame retardancy, especially in terms of toughness, weather resistance, and the impact of flame retardants on the tensile strength of the composites; fourth, the ratio of PPE resin, high-impact polystyrene, and halogen-free flame retardants needs to be further precisely controlled to obtain better flame retardant effects and mechanical strength; finally, the existing preparation processes cannot simultaneously achieve high flame retardancy, high mechanical strength, good appearance, and excellent environmental adaptability, failing to meet the stringent requirements of the photovoltaic industry for key components. Therefore, developing a halogen-free flame-retardant polyphenylene ether composite material for photovoltaic applications that combines excellent flame retardant properties, good mechanical properties, and environmentally friendly characteristics is of great significance for meeting the stringent requirements of the photovoltaic industry and environmental regulations. Summary of the Invention

[0006] To address the potential health hazards of brominated flame retardants in conventional polyphenylene ether resin formulations, as well as the problem of flame retardants reducing the mechanical properties and heat and oxygen resistance of materials, and to overcome the shortcomings of existing polyphenylene ether composite materials in meeting the photovoltaic industry's requirements for heat resistance, aging resistance, UV resistance, and flame retardancy, this invention provides a polyurethane toughening agent and a method for preparing toughened halogen-free flame-retardant polyphenylene ether composite materials thereof.

[0007] The technical solution adopted by this invention to solve its technical problem is as follows: This invention provides a polyurethane toughening agent and a method for preparing the toughened halogen-free flame-retardant polyphenylene ether composite material thereof, comprising the following components in parts by weight:

[0008] Polyphenylene ether resin 50%-70%;

[0009] 10%~20% of flow-modified resin;

[0010] Halogen-free flame retardant 5%-10%;

[0011] Polyurethane toughening agent 5%~15%;

[0012] Enhancer 5%~10%;

[0013] Antioxidant 0.2%~0.5%;

[0014] UV protectant 0.05%~0.5%.

[0015] The material composition of the polyurethane toughening agent of this invention is as follows:

[0016] Component A is a polymer containing active end groups, accounting for 70% to 90% by mass, characterized in that the active end groups are one or more mixtures of polyethylene glycol-200, polyethylene glycol-500, polyethylene glycol-1000, polyethylene glycol-2000, and polyethylene glycol-20000; Component B is a chain extender, accounting for 5% to 15% by mass, characterized in that the chain extender is one or more of diethyltoluene diamine, hydroquinone di(2-hydroxyethyl) ether, and dihydroxyethyl ether hydroquinone; Component C is an isocyanate, accounting for 5% to 15% by mass, characterized in that the isocyanate is one or more of isophoric isocyanate, hexamethylene diisocyanate, and phenyl diisocyanate; Component D is a catalyst, accounting for 0.01% to 0.05% by mass, characterized in that the catalyst is dibutyltin dilaurate; Component E is a modifying agent, accounting for 0.7% to... 1%, characterized in that the modifying agent is one or more of maleic anhydride and fumaric acid.

[0017] The active end-group polymer of this invention is polyethylene glycol-2000 with a mass percentage of 70% to 90%.

[0018] The chain extender of this invention is hydroquinone hydroquinone with a mass fraction of 5-15%;

[0019] The isocyanate of this invention is isophorone diisocyanate with a mass percentage of 5% to 15%;

[0020] The catalyst of this invention is dibutyltin dilaurate, with a mass percentage of 0.01% to 0.05%.

[0021] The modifying agent of this invention is maleic anhydride with a mass percentage of 0.7% to 1%.

[0022] The method for preparing the polyurethane toughening agent of the present invention includes:

[0023] First, the polymer containing active end groups and the chain extender are dried in a vacuum oven containing a desiccant at 90℃~120℃ for 4~6 hours. Then, under a nitrogen atmosphere, the polymer containing active end groups, isocyanate, catalyst, and solvent are added to a reaction vessel and reacted at 80℃~100℃ for 3~5 hours to obtain an isocyanate-terminated prepolymer. Subsequently, a certain amount of chain extender is added to the reaction vessel, and the temperature is maintained to continue the reaction for 3~5 hours. Then, the modifying agent is added, and the reaction is continued for 2~3 hours to obtain a solution containing the product. The polyurethane toughening agent is obtained by filtration through diethyl ether.

[0024] The flow-modified resin of the halogen-free flame-retardant polyphenylene ether composite material of the present invention is one or more of the following polyamide polymers: polyamide-6, polyamide-66, polyamide-46, polyamide-11, polyamide-12, polyamide-610, polyamide-612, polyamide-1010, etc.; polyester polymers such as polyethylene terephthalate, polybutylene terephthalate, polyarylate, and polycarbonate; polystyrene polymers such as general-purpose polystyrene and syndiotactic polystyrene; impact-resistant polystyrene; and styrene copolymers such as acrylonitrile-butadiene-styrene copolymer and styrene-acrylonitrile copolymer.

[0025] The halogen-free flame retardant of the polyphenylene ether composite material of the present invention is one or more of the following phosphorus-based flame retardants: red phosphorus, ammonium phosphate, ammonium polyphosphate, resorcinol bis(diphenylphosphonate), tricresyl phosphate, triphenyl phosphate, hydroquinone bis(diphenyl phosphate), bisphenol bis(diphenyl phosphate), etc., and nitrogen-based flame retardants such as melamine, dicyandiamide, guanidine phosphate, condensed guanidine phosphate, guanidine aminosulfonate, etc.

[0026] The reinforcing agent in the halogen-free flame-retardant polyphenylene ether composite material of the present invention is one or more of the following: glass fiber, carbon fiber, graphene, and carbon nanotubes.

[0027] The antioxidant in the halogen-free flame-retardant polyphenylene ether composite material of the present invention is one or more of the following phenolic antioxidants: antioxidant 1076, antioxidant 1010, antioxidant 1098, antioxidant 1035, antioxidant 1790, etc.

[0028] The UV stabilizer in the halogen-free flame-retardant polyphenylene ether composite material of the present invention is one or more of the following: benzotriazole / benzimidazoles such as UV-P, UV-326, UV-234, and UV-360; hindered amine light stabilizers such as HALS 944, HALS 622, HALS 119, and HALS2020.

[0029] This invention also provides a method for preparing the above-mentioned halogen-free flame-retardant polyphenylene ether composite material, comprising the following steps:

[0030] Step 1: Dry the polyphenylene ether resin, flow-modified resin, polyurethane toughening agent and reinforcing agent at 80-120℃ for 4-6 hours to reduce their moisture content to below 0.05%;

[0031] Step 2: Mix the dried raw materials, halogen-free flame retardant, antioxidant and UV stabilizer in a high-speed mixer according to the specified ratio, and then melt-mix and extrude them through a twin-screw extruder, wherein the length-to-diameter ratio of the twin-screw extruder is 40:1 or higher.

[0032] Step 3: The vacuum extraction pressure of the metering section of the twin-screw extruder is -0.9MPa. Kneading blocks are added to the main feed port, side feed port, natural exhaust port, vacuum exhaust port and conveying section. The application of 90-degree and 45-degree screw elements in the screw assembly is increased. The temperature of each section of the screw is set between 240-300℃. A reasonable main engine speed is set.

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0034] 1. This invention uses a halogen-free flame retardant to replace the traditional brominated flame retardant, effectively inhibiting the generation of harmful bromine-containing substances, enhancing the environmental friendliness and safety of the material, while ensuring the flame retardant effect of the material;

[0035] 2. This invention introduces a high-flowability resin, which improves the processing characteristics of the material and solves the problem of difficult processing of traditional polyphenylene ether resin;

[0036] 3. This invention precisely controls the proportions of polyphenylene ether resin, toughness improver, strength enhancer and halogen-free flame retardant, significantly enhancing the flame retardant properties and mechanical strength of the composite material, achieving a balance between high flame retardancy and high mechanical strength;

[0037] 4. The present invention employs a twin-screw extruder melt mixing process, which ensures the uniform distribution of each component, improves the compatibility and purity of the material, and overcomes the shortcomings of poor modification effects of flame retardants and compatibilizers in the prior art;

[0038] 5. By adding antioxidants and UV stabilizers, this invention significantly improves the heat and oxygen aging resistance and UV resistance of the composite material, meeting the stringent environmental performance requirements of the photovoltaic industry.

[0039] 6. The composite material prepared by the present invention has excellent melt strength, processing fluidity, flame retardancy, high temperature resistance, weather resistance and light aging resistance, and the molded parts have smooth surfaces and good appearance performance, and are especially suitable for extrusion molding of plates and profiles with high requirements for appearance surface. Detailed Implementation

[0040] The present invention will be further illustrated below with reference to embodiments and comparative examples. Without departing from the spirit of the present invention, the present invention should not be limited to the specific contents described in the following embodiments.

[0041] Example 1

[0042] A halogen-free flame-retardant polyphenylene ether / polyamide-66 composite material and its preparation method, comprising the following mass percentages:

[0043] The composition is as follows: 60% polyphenylene ether resin, 15% polyamide-66, 8% aluminum hypophosphite, 10% polyurethane toughening agent, 6.5% glass fiber, 0.3% hindered phenolic antioxidant 1010, and 0.2% UV stabilizer HALS 944.

[0044] The preparation method of this halogen-free flame-retardant polyphenylene ether / polyamide-66 composite material includes the following steps:

[0045] The process parameters for melt extrusion using a twin-screw extruder are as follows: From the feed port to the die head, the temperature gradient for each zone is set as follows: Zone 1: 220-240℃; Zones 2 to 4: 260-285℃; Side feed port: 255-265℃; Zones 5 to 7: 265-280℃; Die head: 260-270℃; Main motor current: 390-400A; Main motor speed: 450rpm; Vacuum extraction pressure in the metering section: approximately -0.9MPa; The length-to-diameter ratio of the twin-screw extruder is 48:1.

[0046] Polyphenylene ether resin, polyamide-66, polyurethane toughening agent, and glass fiber were separately dried in a forced-air drying oven at 100℃ for 5 hours until their moisture content dropped to below 0.05%, and then set aside for later use.

[0047] The dried polyphenylene ether resin, polyurethane toughening agent, aluminum hypophosphite, hindered phenolic antioxidant 1010, and UV stabilizer HALS 944 were pre-mixed evenly in a high-speed mixer according to the above mass ratio. The mixing time was 10 minutes and the mixing speed was 7500 r / min.

[0048] The uniformly mixed material is fed into the twin-screw extruder through the main feed port, while polyamide-66 and glass fiber are added through the side feed port for melt mixing and extrusion. The vacuum extraction pressure in the metering section of the twin-screw extruder is -0.9 MPa to remove low-molecular-weight volatiles and moisture. The twin-screw extruder is configured with a feeding section, melting section, mixing section, venting section, and metering section sequentially from the feed port to the die. The mixing section includes a kneading block, and the application of 90-degree and 45-degree screw elements in the screw assembly is increased. The flame-retardant polyphenylene ether / polyamide-66 alloy is obtained by melt blending through the twin-screw extruder. The extruded strip is then drawn, cooled, and pelletized to obtain granules.

[0049] Example 2

[0050] A halogen-free flame-retardant polyphenylene ether / polybutylene terephthalate composite material and its preparation method, comprising the following mass percentages:

[0051] The composition is as follows: 60% polyphenylene ether resin, 15% polybutylene terephthalate, 8% aluminum hypophosphite, 10% polyurethane toughening agent, 6.5% glass fiber, 0.3% hindered phenolic antioxidant 1010, and 0.2% UV stabilizer HALS 944.

[0052] The preparation method of this halogen-free flame-retardant polyphenylene ether / polybutylene terephthalate composite material includes the following steps:

[0053] The process parameters for melt extrusion using a twin-screw extruder are as follows: From the feed port to the die head, the temperature gradient for each zone is set as follows: Zone 1: 220-240℃; Zones 2 to 4: 260-285℃; Side feed port: 255-265℃; Zones 5 to 7: 265-280℃; Die head: 260-270℃; Main motor current: 390-400A; Main motor speed: 450rpm; Vacuum extraction pressure in the metering section: approximately -0.9MPa; The length-to-diameter ratio of the twin-screw extruder is 48:1.

[0054] Polyphenylene ether resin, polybutylene terephthalate, polyurethane toughening agent, and glass fiber were separately dried in a forced-air drying oven at 100°C for 5 hours until their moisture content dropped to below 0.05%, and then set aside for later use.

[0055] The dried polyphenylene ether resin, polyurethane toughening agent, aluminum hypophosphite, hindered phenolic antioxidant 1010, and UV stabilizer HALS 944 were pre-mixed evenly in a high-speed mixer according to the above mass ratio. The mixing time was 10 minutes and the mixing speed was 7500 r / min.

[0056] The uniformly mixed material is fed into the twin-screw extruder through the main feed port, while polybutylene terephthalate and glass fiber are added through the side feed port for melt mixing and extrusion. The vacuum extraction pressure in the metering section of the twin-screw extruder is -0.9 MPa to remove low-molecular-weight volatiles and moisture. The twin-screw extruder is configured with a feeding section, melting section, mixing section, venting section, and metering section sequentially from the feed port to the die. The mixing section includes a kneading block, and the application of 90-degree and 45-degree screw elements in the screw assembly is increased. Flame-retardant polyphenylene ether / polyamide-66 alloy is obtained by melt blending through the twin-screw extruder. The extruded strip is then drawn, cooled, and pelletized to obtain granules.

[0057] Example 3

[0058] A halogen-free flame-retardant polyphenylene ether / high-impact polystyrene composite material and its preparation method, comprising the following mass percentages:

[0059] The composition is as follows: 60% polyphenylene ether resin, 15% high-impact polystyrene, 8% aluminum hypophosphite, 10% polyurethane toughening agent, 6.5% glass fiber, 0.3% hindered phenolic antioxidant 1010, and 0.2% UV stabilizer HALS 944.

[0060] The preparation method of this halogen-free flame-retardant polyphenylene ether / high-impact polystyrene composite material includes the following steps:

[0061] The process parameters for melt extrusion using a twin-screw extruder are as follows: From the feed port to the die head, the temperature gradient for each zone is set as follows: Zone 1: 220-240℃; Zones 2 to 4: 260-285℃; Side feed port: 255-265℃; Zones 5 to 7: 265-280℃; Die head: 260-270℃; Main motor current: 390-400A; Main motor speed: 450rpm; Vacuum extraction pressure in the metering section: approximately -0.9MPa; The length-to-diameter ratio of the twin-screw extruder is 48:1.

[0062] Polyphenylene ether resin, high-impact polystyrene, polyurethane toughening agent, and glass fiber were separately dried in a forced-air drying oven at 100°C for 5 hours until their moisture content dropped to below 0.05%, and then set aside for later use.

[0063] The dried polyphenylene ether resin, polyurethane toughening agent, aluminum hypophosphite, hindered phenolic antioxidant 1010, and UV stabilizer HALS 944 were pre-mixed evenly in a high-speed mixer according to the above mass ratio. The mixing time was 10 minutes and the mixing speed was 7500 r / min.

[0064] The uniformly mixed material is fed into the twin-screw extruder through the main feed port, while high-impact polystyrene and glass fiber are added through the side feed port for melt mixing and extrusion. The vacuum extraction pressure in the metering section of the twin-screw extruder is -0.9 MPa to remove low-molecular-weight volatiles and moisture. The twin-screw extruder is configured with a feeding section, melting section, mixing section, venting section, and metering section sequentially from the feed port to the die. The mixing section includes a kneading block, and the application of 90-degree and 45-degree screw elements in the screw assembly is increased. Flame-retardant polyphenylene ether / polyamide-66 alloy is obtained by melt blending through the twin-screw extruder. The extruded strip is then drawn, cooled, and pelletized to obtain granules.

[0065] Comparative Example 1

[0066] A halogen-free flame-retardant polyphenylene ether composite material without flow-modified resin, comprising the following mass percentages:

[0067] The composition is as follows: polyphenylene ether resin 75% by mass; aluminum hypophosphite 8% by mass; polyurethane toughening agent 10% by mass; glass fiber 6.5% by mass; hindered phenolic antioxidant 1010 0.3% by mass; UV stabilizer HALS 944 0.2% by mass.

[0068] The preparation method of the halogen-free flame-retardant polyphenylene ether composite material without flow-modified resin includes the following steps:

[0069] The process parameters for melt extrusion using a twin-screw extruder are as follows: From the feed port to the die head, the temperature gradient for each zone is set as follows: Zone 1: 220-240℃; Zones 2 to 4: 260-285℃; Side feed port: 255-265℃; Zones 5 to 7: 265-280℃; Die head: 260-270℃; Main motor current: 390-400A; Main motor speed: 450rpm; Vacuum extraction pressure in the metering section: approximately -0.9MPa; The length-to-diameter ratio of the twin-screw extruder is 48:1.

[0070] Polyphenylene ether resin, polyurethane toughening agent, and glass fiber were separately dried in a forced-air drying oven at 100℃ for 5 hours until their moisture content dropped to below 0.05%, and then set aside for later use.

[0071] The dried polyphenylene ether resin, polyurethane toughening agent, aluminum hypophosphite, hindered phenolic antioxidant 1010, and UV stabilizer HALS 944 were pre-mixed evenly in a high-speed mixer according to the above mass ratio. The mixing time was 10 minutes and the mixing speed was 7500 r / min.

[0072] The uniformly mixed material is fed into the twin-screw extruder through the main feed port, and glass fiber is added through the side feed port for melt mixing and extrusion. The vacuum extraction pressure in the metering section of the twin-screw extruder is -0.9 MPa to remove low-molecular-weight volatiles and moisture. The twin-screw extruder is configured with a feeding section, melting section, mixing section, venting section, and metering section from the feed port to the die head. The mixing section adds a kneading block and increases the application of 90-degree and 45-degree screw elements in the screw assembly. The flame-retardant polyphenylene ether / polyamide-66 alloy is obtained by melt blending through the twin-screw extruder. The extruded strip is drawn, cooled, and then pelletized to obtain particles.

[0073] Comparative Example 2

[0074] A halogen-free flame-retardant polyphenylene ether composite material without polyurethane toughening agent, comprising the following mass percentages:

[0075] The composition is as follows: 60% polyphenylene ether resin, 15% polyamide-66, 8% aluminum hypophosphite, 6.5% glass fiber, 0.3% hindered phenolic antioxidant 1010, and 0.2% UV stabilizer HALS 944.

[0076] The preparation method of the halogen-free flame-retardant polyphenylene ether composite material without polyurethane toughening agent includes the following steps:

[0077] The process parameters for melt extrusion using a twin-screw extruder are as follows: From the feed port to the die head, the temperature gradient for each zone is set as follows: Zone 1: 220-240℃; Zones 2 to 4: 260-285℃; Side feed port: 255-265℃; Zones 5 to 7: 265-280℃; Die head: 260-270℃; Main motor current: 390-400A; Main motor speed: 450rpm; Vacuum extraction pressure in the metering section: approximately -0.9MPa; The length-to-diameter ratio of the twin-screw extruder is 48:1.

[0078] Polyphenylene ether resin, polyamide-66, and glass fiber were separately dried in a forced-air drying oven at 100°C for 5 hours until their moisture content dropped to below 0.05%, and then set aside for later use.

[0079] The dried polyphenylene ether resin, aluminum hypophosphite, hindered phenolic antioxidant 1010, and UV stabilizer HALS 944 were pre-mixed evenly in a high-speed mixer according to the above mass ratio. The mixing time was 10 minutes and the mixing speed was 7500 r / min.

[0080] The uniformly mixed material is fed into the twin-screw extruder through the main feed port, while polyamide-66 and glass fiber are added through the side feed port for melt mixing and extrusion. The vacuum extraction pressure in the metering section of the twin-screw extruder is -0.9 MPa to remove low-molecular-weight volatiles and moisture. The twin-screw extruder is configured with a feeding section, melting section, mixing section, venting section, and metering section sequentially from the feed port to the die. The mixing section includes a kneading block, and the application of 90-degree and 45-degree screw elements in the screw assembly is increased. The flame-retardant polyphenylene ether / polyamide-66 alloy is obtained by melt blending through the twin-screw extruder. The extruded strip is then drawn, cooled, and pelletized to obtain granules.

[0081] Comparative Example 3

[0082] A flame-retardant-free polyphenylene ether composite material, comprising the following mass percentages:

[0083] The composition is as follows: 60% polyphenylene ether resin, 15% polyamide-66, 10% polyurethane toughening agent, 6.5% glass fiber, 0.3% hindered phenolic antioxidant 1010, and 0.2% UV stabilizer HALS 944.

[0084] The preparation method of this halogen-free flame-retardant polyphenylene ether / polyamide-66 composite material includes the following steps:

[0085] The process parameters for melt extrusion using a twin-screw extruder are as follows: From the feed port to the die head, the temperature gradient for each zone is set as follows: Zone 1: 220-240℃; Zones 2 to 4: 260-285℃; Side feed port: 255-265℃; Zones 5 to 7: 265-280℃; Die head: 260-270℃; Main motor current: 390-400A; Main motor speed: 450rpm; Vacuum extraction pressure in the metering section: approximately -0.9MPa; The length-to-diameter ratio of the twin-screw extruder is 48:1.

[0086] Polyphenylene ether resin, polyamide-66, polyurethane toughening agent, and glass fiber were separately dried in a forced-air drying oven at 100℃ for 5 hours until their moisture content dropped to below 0.05%, and then set aside for later use.

[0087] The dried polyphenylene ether resin, polyurethane toughening agent, hindered phenolic antioxidant 1010 and UV stabilizer HALS944 were pre-mixed evenly in a high-speed mixer according to the above mass ratio. The mixing time was 10 minutes and the mixing speed was 7500 r / min.

[0088] The uniformly mixed material is fed into the twin-screw extruder through the main feed port, while polyamide-66 and glass fiber are added through the side feed port for melt mixing and extrusion. The vacuum extraction pressure in the metering section of the twin-screw extruder is -0.9 MPa to remove low-molecular-weight volatiles and moisture. The twin-screw extruder is configured with a feeding section, melting section, mixing section, venting section, and metering section sequentially from the feed port to the die. The mixing section includes a kneading block, and the application of 90-degree and 45-degree screw elements in the screw assembly is increased. The flame-retardant polyphenylene ether / polyamide-66 alloy is obtained by melt blending through the twin-screw extruder. The extruded strip is then drawn, cooled, and pelletized to obtain granules.

[0089] Comparative Example 4

[0090] A halogen-free flame-retardant polyphenylene ether composite material containing no antioxidants or UV stabilizers, comprising the following mass percentages:

[0091] The composition is as follows: 60% polyphenylene ether resin, 15% polyamide-66, 8% aluminum hypophosphite, 10% polyurethane toughening agent, and 6.5% glass fiber.

[0092] The preparation method of this halogen-free flame-retardant polyphenylene ether / polyamide-66 composite material includes the following steps:

[0093] The process parameters for melt extrusion using a twin-screw extruder are as follows: From the feed port to the die head, the temperature gradient for each zone is set as follows: Zone 1: 220-240℃; Zones 2 to 4: 260-285℃; Side feed port: 255-265℃; Zones 5 to 7: 265-280℃; Die head: 260-270℃; Main motor current: 390-400A; Main motor speed: 450rpm; Vacuum extraction pressure in the metering section: approximately -0.9MPa; The length-to-diameter ratio of the twin-screw extruder is 48:1.

[0094] Polyphenylene ether resin, polyamide-66, polyurethane toughening agent, and glass fiber were separately dried in a forced-air drying oven at 100℃ for 5 hours until their moisture content dropped to below 0.05%, and then set aside for later use.

[0095] The dried polyphenylene ether resin, polyurethane toughening agent, and aluminum hypophosphite were pre-mixed evenly in a high-speed mixer according to the above mass ratio. The mixing time was 10 minutes and the mixing speed was 7500 r / min.

[0096] The uniformly mixed material is fed into the twin-screw extruder through the main feed port, while polyamide-66 and glass fiber are added through the side feed port for melt mixing and extrusion. The vacuum extraction pressure in the metering section of the twin-screw extruder is -0.9 MPa to remove low-molecular-weight volatiles and moisture. The twin-screw extruder is configured with a feeding section, melting section, mixing section, venting section, and metering section sequentially from the feed port to the die. The mixing section includes a kneading block, and the application of 90-degree and 45-degree screw elements in the screw assembly is increased. The flame-retardant polyphenylene ether / polyamide-66 alloy is obtained by melt blending through the twin-screw extruder. The extruded strip is then drawn, cooled, and pelletized to obtain granules.

[0097] Performance testing

[0098] The materials prepared in the above embodiments and comparative examples were injection molded to prepare specimens, wherein:

[0099] (1) Tensile strength and fracture strain: tested according to ISO 527 at a speed of 50 mm / min;

[0100] (2) Notched impact strength of cantilever beam: tested according to ISO 179, 23℃, pendulum 5.5J;

[0101] (3) Density: Tested according to ISO 1183;

[0102] (5) Vertical burning: 1.6 mm as tested according to UL94;

[0103] (6) Bending strength: Tested according to ISO 178 at a speed of 2 mm / min;

[0104] (7) Heat distortion temperature: tested according to ISO 75, heating rate 2 ℃ / min;

[0105] (8) Volume resistivity: Tested according to IEC 62631-3-1, 23°C, 50%RH;

[0106] (9) Dielectric strength: Tested according to IEC 60243-1;

[0107] (10) Weather resistance: According to ISO 4892-2, after 1000 hours of xenon lamp aging, the tensile strength retention rate.

[0108]

[0109] Mechanical properties (tensile, bending, impact):

[0110] Examples 1-3 demonstrate a good balance of overall performance. Example 1, modified with PA66, exhibits the best overall toughness and strength (thanks to the inherent strength of PA66 and the polyurethane toughening agent); Example 2, modified with PBT, has higher rigidity (flexural strength, HDT); Example 3, modified with HIPS, may have lower cost, but its strength and heat resistance are slightly inferior.

[0111] Comparative Example 1 (without flow modifier): Poor processability leads to uneven mixing and potential defects, resulting in a decrease in all mechanical properties.

[0112] Comparative Example 2 (without polyurethane toughening agent): Impact strength plummeted, elongation at break decreased, and the material became brittle, but rigidity indicators (tensile strength, flexural strength) may have increased slightly due to the relatively higher filler content.

[0113] Comparative Example 3 (without flame retardant): Due to the absence of potential negative impacts of flame retardants on the molecular chain, its pure mechanical properties (tensile, bending, impact) are even slightly better than those of the corresponding Example 1.

[0114] Comparative Example 4 (without stabilizer): The initial mechanical properties were comparable to those of Example 1, as it only lacked the anti-aging additive and did not change the initial molecular structure.

[0115] Flame retardant performance (UL94):

[0116] Examples 1-3 & Comparative Examples 2, 4: all contained 8% aluminum hypophosphite halogen-free flame retardant, achieving a V-0 rating.

[0117] Comparative Example 1: Poor processing may lead to uneven dispersion of flame retardant, resulting in a decrease in flame retardant rating to V-1.

[0118] Comparative Example 3: Contains no flame retardants and can only achieve the lowest HB rating.

[0119] Heat resistance (HDT):

[0120] The addition of reinforcing agents (glass fiber) and crystalline polymers (PA66, PBT) improved HDT.

[0121] In Comparative Example 2, due to the lack of polyurethane toughening agent, the relative reinforcing effect of glass fiber was more significant, resulting in the highest HDT.

[0122] Example 3 has the lowest HDT due to the use of amorphous HIPS.

[0123] Electrical performance:

[0124] All formulations exhibit good electrical properties, meeting the requirements of photovoltaic devices (≥10^16 Ω·cm, ≥25 kV / mm).

[0125] Example 2, based on PBT, exhibits the highest volume resistivity and dielectric strength, which is related to the excellent electrical insulation properties of PBT itself.

[0126] Weather resistance:

[0127] Examples 1-3: Thanks to the synergistic effect of antioxidants and UV stabilizers, the tensile strength retention rate exceeded 85% after 1000 hours of xenon lamp aging, demonstrating excellent resistance to photo-oxidative aging.

[0128] Comparative Example 4: Due to the complete lack of a stable system, the material underwent severe degradation during the aging process, and the strength retention rate dropped significantly to 55%, which completely failed to meet the requirements for long-term outdoor use of photovoltaics.

[0129] Although other comparative examples contain stabilizers, their weather resistance is slightly lower than that of the examples due to unbalanced formulations (such as poor processing or poor compatibility).

[0130] Experimental data strongly support the core claim of this invention—that is, through the compounding of the specific components and proportions, and the key preparation process (side feeding, vacuum degassing, kneading block), a halogen-free flame-retardant polyphenylene ether composite material that simultaneously meets the requirements of high flame retardancy, high mechanical strength, excellent weather resistance and good processability has been successfully prepared. It is particularly suitable for the manufacture of junction boxes, connectors and other components of photovoltaic modules, and can meet the requirements of long-term outdoor use of photovoltaic products.

[0131] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A flame-retardant polyphenylene ether composite material, characterized in that, Preparation of polyurethane toughening agents and compounding and preparation methods of flame-retardant polyphenylene ether composites.

2. The preparation method of the halogen-free flame-retardant polyphenylene ether composite material according to claim 1, wherein the combined formulation is as follows: Polyphenylene oxide resin content: 50% ~ 70% by weight; The flow-modified resin content is 10% to 20% by weight. Halogen-free flame retardant: 5% ~ 10% by weight; The polyurethane toughening agent comprises 5% to 15% by weight. The reinforcing agent comprises 5% to 10% by weight. Antioxidant content: 0.2% ~ 0.5% by weight; UV protectant percentage: 0.05% ~ 0.5% by mass.

3. The material composition of the polyurethane toughening agent according to claim 1 composition: Component A is a polymer containing active end groups, comprising 70% to 90% by mass, characterized in that... The active end groups are one or more of polyethylene glycol-200, polyethylene glycol-500, polyethylene glycol-1000, polyethylene glycol-2000, and polyethylene glycol-20000; Component B is a chain extender, comprising 5% to 15% by mass, characterized in that the chain extender is one or more of diethyltoluenediamine, hydroquinone di(2-hydroxyethyl) ether, and dihydroxyethyl ether hydroquinone. Component C is an isocyanate, comprising 5%-15% by mass, characterized in that the isocyanate is one or more of isophoric isocyanate, hexamethylene diisocyanate, and phthalimethylene diisocyanate; Component D is a catalyst, with a mass percentage of 0.01% to 0.05%, characterized in that the catalyst is dibutyltin dilaurate; Component E is a modifying agent, with a mass percentage of 0.7% to 1%, characterized in that the modifying agent is one or more of maleic anhydride and fumaric acid; The active end-group polymer is polyethylene glycol-2000 at a mass percentage of 70% to 90%; the chain extender is hydroquinone hydroquinone at a mass percentage of 5% to 15%; the isocyanate is isophorone diisocyanate at a mass percentage of 5% to 15%; the catalyst is dibutyltin dilaurate at a mass percentage of 0.01% to 0.05%; and the modifying agent is maleic anhydride at a mass percentage of 0.7% to 1%. Preparation methods include: First, the polymer containing active end groups and the chain extender are dried in a vacuum oven containing a desiccant at 90℃~120℃ for 4~6 hours. Then, under a nitrogen atmosphere, the polymer containing active end groups, isocyanate, catalyst, and solvent are added to a reaction vessel and reacted at 80℃~100℃ for 3~5 hours to obtain an isocyanate-terminated prepolymer. Subsequently, a certain amount of chain extender is added to the reaction vessel, and the temperature is maintained to continue the reaction for 3~5 hours. Then, the modifying agent is added, and the reaction is continued for 2~3 hours to obtain a solution containing the product. The polyurethane toughening agent is obtained by filtration through diethyl ether.

4. The halogen-free flame-retardant polyphenylene ether composite material according to claim 1, characterized in that, The flow-modified resin is selected from one or more of the following: polyamide polymers such as polyamide-6, polyamide-66, polyamide-46, polyamide-11, polyamide-12, polyamide-610, polyamide-612, and polyamide-1010; polyester polymers such as polyethylene terephthalate, polybutylene terephthalate, polyarylate, and polycarbonate; polystyrene polymers such as general-purpose polystyrene and syndiotactic polystyrene; impact-resistant polystyrene; and styrene copolymers such as acrylonitrile-butadiene-styrene copolymer and styrene-acrylonitrile copolymer.

5. The halogen-free flame-retardant polyphenylene ether composite material according to claim 1, characterized in that, The halogen-free resistor The flame retardant is selected from one or more phosphorus-based flame retardants such as red phosphorus, ammonium phosphate, ammonium polyphosphate, resorcinol bis(diphenylphosphonate), tricresyl phosphate, triphenyl phosphate, hydroquinone bis(diphenyl phosphate), bisphenol bis(diphenyl phosphate), melamine, dicyandiamide, guanidine phosphate, condensed guanidine phosphate, and guanidine aminosulfonate.

6. The halogen-free flame-retardant polyphenylene ether composite material according to claim 1, characterized in that, The reinforcing agent is selected from one or more of glass fiber, carbon fiber, graphene, and carbon nanotubes.

7. The halogen-free flame-retardant polyphenylene ether composite material according to claim 1, characterized in that, The antioxidant is selected from one or more phenolic antioxidants such as antioxidant 1076, antioxidant 1010, antioxidant 1098, antioxidant 1035, and antioxidant 1790.

8. The halogen-free flame-retardant polyphenylene ether composite material according to claim 1, characterized in that, The UV stabilizer is selected from one or more of the following: benzotriazole / benzimidazoles such as UV-P, UV-326, UV-234, and UV-360; hindered amine light stabilizers such as HALS 944, HALS 622, HALS 119, and HALS2020.

9. A method for preparing a flame-retardant polyphenylene ether composite material as described in any one of claims 1-8, characterized in that: (1) First, place the polyphenylene ether resin, flow-modified resin, polyurethane toughening agent and reinforcing agent in a forced-air drying oven and dry them at 80-120℃ for 4-6 hours to reduce their moisture content to below 0.05% for later use; (2) The dried polyphenylene ether resin, flow-modified resin, polyurethane toughening agent, reinforcing agent, halogen-free flame retardant, antioxidant and anti-UV agent are pre-mixed evenly in a high-speed mixer according to a certain mass ratio requirement, and then added from the main feed port to a twin-screw extruder with a length-to-diameter ratio of 40:1 or higher for melt mixing and extrusion. (3) The vacuum extraction pressure of the metering section of the twin-screw extruder is -0.9MPa to remove low molecular weight volatiles and moisture; in addition to the main feed port, side feed port, natural exhaust port, vacuum exhaust port and conveying section, kneading blocks are added to other sections, the application of 90-degree and 45-degree screw elements in the screw assembly is increased, the temperature of each section of the screw is set between 240-300℃, and a reasonable main machine speed is set. Halogen-free flame-retardant polyphenylene ether composite material is obtained by melt blending through the twin-screw extruder.

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