Aramid fabric reinforced new energy vehicle fire extinguishing cover material and preparation method thereof

Abstract

The present application relates to the technical field of new energy vehicle fire extinguishing materials, and particularly relates to an aramid fabric reinforced new energy vehicle fire cover material and a preparation method thereof. The fire cover material comprises, from inside to outside, a fire extinguishing microcapsule silica gel resin coating, high-silica glass cloth, an expanded microsphere silica gel resin coating, aramid fabric and an ultraviolet resistant fireproof coating layer. The fire extinguishing microcapsule silica gel resin coating comprises fire extinguishing microcapsules and silica gel resin, wherein the mass fraction of the fire extinguishing microcapsules in the fire extinguishing microcapsule silica gel resin is 15%-20%. The expanded microsphere silica gel resin coating comprises expanded microspheres and silica gel resin, and the mass fraction of the expanded microspheres in the expanded microsphere silica gel resin is 5%-10%. The fire cover material has the advantages of rapid fire extinguishing, heat insulation and flame resistance, explosion resistance and impact resistance.

Description

Technical Field

[0001] This invention relates to an aramid fabric-reinforced fire extinguishing cover material for new energy vehicles and its preparation method, belonging to the technical field of fire extinguishing materials for new energy vehicles. Background Technology

[0002] Safety incidents caused by fires in new energy vehicles have always been a topic of great concern. The main causes of these fires include: thermal runaway combustion due to the chemical activity of battery materials, management software malfunctions, overcharging, or external damage; battery system malfunctions leading to combustion; and the inherent characteristics of lithium-ion batteries, which are more flammable than other types of batteries, thus having a higher probability of spontaneous combustion. Furthermore, compared to traditional gasoline vehicles, fires in new energy vehicles are difficult to detect, spread rapidly, are difficult to extinguish, and are highly prone to explosion, producing large amounts of toxic fumes. Even after extinguishing the fire, there is a high risk of reignition.

[0003] Therefore, when a new energy vehicle catches fire, how to quickly and safely control the fire, extinguish the source, and prevent casualties and property damage is an urgent problem to be solved. Especially in parking lots, residential areas, charging stations, underground garages, and other similar locations, when a vehicle catches fire, the fire spreads rapidly, easily igniting surrounding vehicles and property, leading to a larger fire and incalculable losses. Therefore, developing a fire extinguishing cover is of significant value.

[0004] Patent application CN118698063A discloses a novel fire extinguishing cover, mainly comprising a fire extinguishing cover body with a heat insulation layer and a counterweight structure installed on the outside of the body, which extinguishes fires by isolating oxygen; Patent CN208372328U discloses a foldable fire extinguishing cover for fighting electric bicycle fires, mainly comprising a frame unit and a fireproof cloth cover, the fireproof cloth cover being fixed to the frame unit, and the fireproof cloth cover being made of flame-retardant fabric such as graphitized carbon fiber cloth or ceramic fiber cotton blanket, which can be quickly extinguished during use. The device unfolds to form a large, three-dimensional, arched fire extinguishing hood, capable of extinguishing small, three-dimensional fires in their initial stages. Patent application CN118698063A discloses a fire extinguishing device for new energy vehicles, primarily comprising a basalt fiber cloth base, a silicone coating, and a basalt woven water hose with inlets and several spray holes. This device can be quickly deployed to extinguish fires in new energy vehicles, achieving rapid and continuous cooling of the burning vehicle, isolating it from the air, and preventing the fire from spreading to other vehicles and combustibles. While the aforementioned fire extinguishing hood device has good fire-retardant properties, the fire in new energy vehicles develops very rapidly and is prone to explosion. The device cannot quickly and efficiently extinguish the fire at the moment of combustion, potentially missing the optimal time to extinguish the fire. Furthermore, the main materials used in the aforementioned fire extinguishing hood device, such as graphitized carbon fiber cloth, ceramic fiber blankets, and basalt fiber cloth, have low impact resistance and cannot effectively withstand damage caused by combustion and explosion, easily leading to the failure of the fire extinguishing device and the inability to continue preventing the fire from spreading.

[0005] In response to the problems existing in the main materials of the aforementioned fire extinguishing devices, there is a need for a new energy vehicle fire extinguishing cover material that can rapidly release extinguishing agents, is heat-resistant and heat-insulating, and is explosion-proof and impact-resistant. This material can quickly release extinguishing agents to extinguish the initial fire source in the early stages of a fire in a new energy vehicle, and at the same time, it can withstand the impact of combustion and explosion in the case of a large fire, protecting the safety of people and property around the fire point and avoiding greater casualties and economic losses. Summary of the Invention

[0006] This invention addresses the problems of simple structure, poor fire extinguishing time, and weak explosion-proof and impact-resistant properties in the main protective materials of existing fire extinguishing devices for new energy vehicles. It provides an aramid fabric-reinforced fire extinguishing cover material for new energy vehicles and its preparation method. The fire extinguishing cover material has the advantages of rapid fire extinguishing, heat insulation and flame retardancy, and explosion-proof and impact-resistant properties.

[0007] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: an aramid fabric reinforced fire extinguishing cover material for new energy vehicles, wherein the fire extinguishing cover material comprises, from the inside out: a fire extinguishing microcapsule silicone resin coating, a high-silica fiberglass cloth, an expanded microsphere silicone resin coating, an aramid fabric, and an anti-ultraviolet fireproof coating layer.

[0008] Furthermore, the fire extinguishing microcapsule silicone resin coating comprises fire extinguishing microcapsules and silicone resin, wherein the fire extinguishing microcapsules are added to the fire extinguishing microcapsule silicone resin at a mass ratio of 15%-20%.

[0009] Furthermore, the fire extinguishing microcapsule includes a fire extinguishing agent and a coating material; The extinguishing agent includes perfluorohexanone and ethyl nonafluorobutyl ether; The coating material is polystyrene or polymethyl methacrylate.

[0010] Furthermore, the particle size of the fire extinguishing microcapsules is 10µm-80µm, and the surface of the fire extinguishing microcapsules is treated with a silane coupling agent and then added to silicone resin to form the fire extinguishing microcapsule silicone resin.

[0011] Furthermore, the high-silica glass fiber yarn is woven using a machine weaving process to obtain the high-silica glass fiber cloth with a plain weave, twill weave, or satin weave structure; The high-silica glass fiber yarn has a SiO2 content of ≥96% and a linear density of 150tex-200tex. The areal density of the high-silica fiberglass cloth is 300 g / m². 2 -600g / m 2 .

[0012] Furthermore, the expanded microsphere silicone resin in the expanded microsphere silicone resin coating comprises expanded microspheres and silicone resin, and the mass of the expanded microspheres added to the expanded microsphere silicone resin is 5%-10%.

[0013] Furthermore, the expanded microspheres comprise an inner layer, a middle layer, and an outer layer, wherein the inner layer comprises C3-C 13 Liquid hydrocarbon and fluorinated ether foaming agent, with an intermediate layer of acrylonitrile-methacrylonitrile copolymer or acrylate-acrylamide copolymer, and an outer layer of cross-linked tetravinylsilane network with dicumyl peroxide and maleic anhydride grafted polyolefin; The expanded microspheres have a particle size of 5µm-50µm.

[0014] Furthermore, the aramid fabric is an aramid fabric with a plain weave, twill weave, or satin weave structure obtained by machine weaving para-aramid filament yarns. The linear density of para-aramid filament yarn is 600D-1500D; The areal density of the aramid fabric is 150 g / m³. 2 -300g / m 2 .

[0015] Furthermore, the UV-resistant fire-retardant coating layer includes a film-forming component, a flame-retardant component, and a UV-resistant component; The film-forming component includes epoxy resin emulsion and vinyl acetate emulsion; the flame-retardant component includes zinc borate and cobalt aluminate; and the UV-resistant component includes nano-TiO2.

[0016] This invention also discloses a method for preparing an aramid fabric-reinforced fire extinguisher cover material for new energy vehicles, wherein the preparation method is as follows: S1. The fire extinguishing microcapsule silicone resin is uniformly coated on the fire-prone side surface of the high-silica fiberglass cloth and cured to form a fire extinguishing microcapsule silicone resin coating. S2. The expanded microsphere silicone resin is uniformly coated on the other surface of the high silica fiber cloth in step S1 to form an expanded microsphere silicone resin coating. S3. The aramid fabric is attached to the expanded microsphere silicone resin coating of step S2 and cured. S4. The UV-resistant fireproof coating is uniformly applied to the surface of the aramid fabric in step S3 to form a UV-resistant fireproof coating layer. Finally, after curing treatment, the fire extinguishing cover material is obtained.

[0017] The beneficial effects of this invention are: The fireproof cover material of this invention has the advantages of rapid fire extinguishing, heat insulation and flame retardancy, explosion-proof and impact-resistant properties, by the synergistic interaction of the fire extinguishing microcapsule silicone resin coating, high silica fiber cloth, expanded microsphere silicone resin coating, aramid fabric and UV-resistant fireproof coating layer.

[0018] Specifically, the fireproof cover material of the present invention is coated with silicone resin containing fire extinguishing microcapsules on the fire-prone side, which can quickly release fire extinguishing agent when a new energy vehicle catches fire, extinguish the initial fire source in time, and effectively prevent the fire from developing and spreading.

[0019] High-silica fiberglass cloth and expanded microsphere silicone resin are used as the heat-resistant insulation layer. The high-silica fiberglass cloth can be used for a long time at 1000℃, and the short-term temperature resistance can reach 1200℃ to 1650℃. The softening point is close to 1700℃. When a new energy vehicle is burning, it can effectively prevent the spread of flames. At the same time, the silicone resin will form a dense structure due to the high temperature of combustion, which can effectively isolate oxygen from entering, thereby achieving a certain degree of fire extinguishing effect. The expanded microsphere silicone resin can react and expand rapidly under high temperature conditions, which can effectively reduce heat transfer and prevent the outer aramid fabric from losing strength due to excessive temperature.

[0020] In addition, the fireproof cover material described in this invention uses aramid fabric as an explosion-proof and impact-resistant reinforcement. Aramid fabric has a series of performance advantages such as flame retardancy, high temperature resistance, and high impact strength. When a new energy vehicle burns and an explosion occurs, it can effectively prevent the explosive from flying and injuring people and prevent the fireproof cover from breaking and failing, thereby improving the overall safety protection capability of the fireproof cover. Detailed Implementation

[0021] The specific embodiments of the present invention will be described in detail below. The present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used is for describing particular embodiments only and is not intended to limit the invention.

[0023] A fire extinguishing cover material for new energy vehicles reinforced with aramid fabric, the fire extinguishing cover material comprising, from the inside out: a fire extinguishing microcapsule silicone resin coating, a high-silica fiberglass cloth, an expanded microsphere silicone resin coating, aramid fabric, and an anti-ultraviolet fireproof coating layer.

[0024] Specifically, the fire extinguishing microcapsule silicone resin coating comprises fire extinguishing microcapsules and silicone resin, wherein the fire extinguishing microcapsules are added to the fire extinguishing microcapsule silicone resin at a mass ratio of 15%-20%. The fire extinguishing microcapsules and silicone resin are mixed uniformly using a mechanical stirring method.

[0025] Specifically, the fire extinguishing microcapsule includes a fire extinguishing agent and a coating material; The extinguishing agent uses perfluorohexanone, which has a low boiling point, is environmentally friendly and non-toxic, and has high extinguishing efficiency, as the main component. Ethyl nonafluorobutyl ether is added as an azeotropic component to improve storage stability, reduce volatilization at room temperature, and synergistically extinguish fires with perfluorohexanone. The coating material is selected from materials such as polystyrene or polymethyl methacrylate, which have good compatibility with silicone resin, high thermal stability, and controllable burst temperature, to ensure good bonding performance and high dispersion uniformity between the fire extinguishing microcapsules and silicone resin.

[0026] Specifically, the fire extinguishing microcapsules have a particle size of 10µm-80µm, and the surface of the fire extinguishing microcapsules is treated with a silane coupling agent and then added to silicone resin to form the fire extinguishing microcapsule silicone resin.

[0027] The silicone resin is a room temperature curing addition-type silicone resin, which has excellent properties such as low temperature curing, high expansion and ceramic thermal insulation.

[0028] Specifically, the high-silica glass fiber cloth is made by weaving high-silica glass fiber yarn to obtain plain weave, twill weave, or satin weave structures. The high-silica glass fiber yarn has a SiO2 content of ≥96% and a linear density of 150tex-200tex. The areal density of the high-silica fiberglass cloth is 300 g / m². 2 -600g / m 2 The thickness is 0.3mm-1mm.

[0029] Specifically, the expanded microsphere silicone resin in the expanded microsphere silicone resin coating includes expanded microspheres and silicone resin. The expanded microspheres are added to the expanded microsphere silicone resin at a mass of 5%-10%, and the expanded microspheres and silicone resin are mixed evenly by mechanical stirring.

[0030] Specifically, the expanded microspheres comprise an inner layer, a middle layer, and an outer layer. The inner layer is made of C3-C, which undergoes thermal vaporization and has a high thermal expansion rate. 13 Liquid hydrocarbon and fluorinated ether foaming agent, the middle layer uses acrylonitrile-methacrylonitrile copolymer or acrylate-acrylamide copolymer to achieve foaming temperature control, and the outer layer uses cross-linked tetravinylsilane network with dicumyl peroxide and maleic anhydride grafted polyolefin to improve thermal stability and interfacial bonding. The expanded microspheres have a particle size of 5µm-50µm.

[0031] More specifically, the silicone resin used in the mixing of the expanded microspheres and the silicone resin used in the mixing of the fire extinguishing microcapsules have the same composition.

[0032] Specifically, the aramid fabric is an aramid fabric with a plain weave, twill weave, or satin weave structure obtained by machine weaving para-aramid filament yarns. The linear density of para-aramid filament yarn is 600D-1500D; The areal density of the aramid fabric is 150 g / m³. 2 -300g / m 2 The thickness is 0.2mm-0.6mm.

[0033] Specifically, the UV-resistant fire-retardant coating layer includes a film-forming component, a flame-retardant component, and a UV-resistant component; The film-forming component includes epoxy resin emulsion and vinyl acetate emulsion; the flame-retardant component includes zinc borate and cobalt aluminate; and the UV-resistant component includes nano-TiO2.

[0034] A method for preparing an aramid fabric-reinforced fire extinguisher material for new energy vehicles, wherein the preparation method comprises: S1. Apply fire extinguishing microcapsule silicone resin uniformly to the fire-prone surface of high-silica fiberglass cloth using a roller coating method. The coating mass is 290g / m²-500g / m². Specific coating conditions are: roller pressure of 0.1MPa-0.3MPa (increasing with increasing resin coating mass), and roller speed of 5m / min-10m / min (decreasing with increasing resin coating mass). A uniform fire extinguishing microcapsule silicone resin coating is formed on the fire-prone surface of the high-silica fiberglass cloth. Finally, allow it to stand at room temperature for 24 hours to achieve complete curing. S2. The expanded microsphere silicone resin is uniformly coated onto the surface of the high-silica fiberglass cloth without the fire extinguishing microcapsule silicone resin obtained in step S1 using a pressure roller method. The coating mass is 140g / m²-250g / m². The specific coating conditions are: the pressure of the coating roller is 0.08MPa-0.2MPa (the pressure of the roller increases with the increase of the resin coating mass), and the speed of the roller is 6m / min-12m / min (the speed of the roller decreases with the increase of the resin coating mass). A uniform, incompletely cured expanded microsphere silicone resin coating is formed on the surface of the high-silica fiberglass cloth without the fire extinguishing microcapsule silicone resin. S3. The aramid fabric is simultaneously coated onto the expanded microsphere silicone resin coating of step S2 using a pressure roller method. Under the pressure of 0.2 MPa of the pressure roller, the aramid fabric and the expanded microsphere silicone resin coating of step S2 are completely coated. Finally, the coating is allowed to stand at room temperature for 24 hours to achieve complete curing. S4. The UV-resistant and fire-retardant coating is uniformly applied to the surface of the aramid fabric from step S3 using a roller press method to form a UV-resistant and fire-retardant coating layer, with a coating mass of 100 g / m². 2 -200g / m 2 After coating, the material is cured at room temperature to obtain the fire extinguishing cover material.

[0035] The main structure of the fire extinguishing cover is made by stitching together ultra-high temperature resistant quartz fiber. Fire-resistant pull rings and counterweights are set on the edges to facilitate quick coverage and fit to the vehicle body. When the fire extinguishing cover is quickly placed over the surface of the burning new energy vehicle, the fire extinguishing microcapsule silicone resin on the fire-prone side will rapidly rupture when the temperature reaches about 120°C, releasing perfluorohexanone and ethyl nonafluorobutyl ether azeotropic fire extinguishing agent. This rapidly reduces the flame temperature and isolates oxygen, achieving rapid suppression of the initial fire source. At the same time, ethyl nonafluorobutyl ether, as an azeotropic component, can delay the volatilization of perfluorohexanone, prolong the action time of the fire extinguishing agent, and further enhance the fire prevention and control performance to prevent the spread of fire. As the fire spread, the high-silica fiberglass cloth formed a stable heat insulation barrier at high temperatures, preventing heat from being transferred outwards. It also has long-lasting high-temperature resistance. Under the experimental conditions of 1000℃ / 2h flame combustion, the high-silica fiberglass cloth did not show any damage or flame penetration. Expandable microsphere silicone resin reacts and expands rapidly at temperatures above 160℃, forming a porous heat insulation layer that blocks oxygen and heat transfer, aiding in suffocation fire suppression. Simultaneously, the silicone resin also possesses high-temperature ceramicization properties, forming a dense barrier. In synergy with high-silica fiberglass cloth and expandable microspheres, they together constitute a heat-resistant insulation layer with an insulation rate of up to 85%. This effectively blocks heat transfer to the outer aramid fabric, ensuring its performance stability and preventing damage to surrounding personnel and objects from high temperatures. Aramid fabric, as the outer reinforcement, has the characteristics of high strength and high modulus. When a vehicle is burning and exploding, it can effectively resist impact and flying debris, prevent the fire extinguisher from breaking and failing, and protect the safety of surrounding personnel and property. The UV-resistant fire-retardant coating layer effectively delays the aging of materials during outdoor use through physical shielding and chemical quenching, improving the durability and reusability of fire extinguishing covers for daily outdoor use.

[0036] More specifically, the raw materials used in the embodiments of the present invention are as follows: Silicone resin: Shanghai Tongshuai Organosilicon Materials Co., Ltd., HT-89-71 model silicone resin; Fire extinguishing microcapsules: Zhongxiaoan Technology Industry (Shenzhen) Co., Ltd., QFT40-SFS model fire extinguishing microcapsules; Expanded microspheres: Jining Hongming Chemical Reagent Co., Ltd., PG40 type expanded microspheres; Epoxy resin emulsion: Zhejiang Anbang New Material Development Co., Ltd., AB-EP-20 (PM) waterborne epoxy resin emulsion; Acrylic-vinyl acetate emulsion: Dow Chemical, ROVACE 661 acrylic-vinyl acetate emulsion; UV-resistant fire-retardant coating: By weight, the UV-resistant fire-retardant coating comprises 35 parts epoxy resin emulsion, 25 parts vinyl acetate emulsion, 20 parts zinc borate, 8 parts cobalt aluminate, 25 parts nano TiO2, 6 parts deionized water, 0.5 parts dispersant (sodium polycarboxylate), 0.3 parts defoamer (organosilicon, TEGO Foamex 805 from Chuangying Industrial Group), and 0.2 parts film-forming aid (dodecyl alcohol ester).

[0037] Example 1 A fire extinguishing cover material for new energy vehicles reinforced with aramid fabric, the fire extinguishing cover material for new energy vehicles comprising a fire extinguishing microcapsule silicone resin layer, a high-silica fiberglass cloth, an expandable microsphere silicone resin layer, aramid fabric, and an anti-ultraviolet fireproof coating layer.

[0038] The preparation method of an aramid fabric-reinforced fire extinguishing cover material for new energy vehicles is as follows: S1. Apply fire extinguishing microcapsule silicone resin evenly to the fire-prone surface of high-silica fiberglass cloth using a roller coating method. The coating mass is 300±10 g / m². Specific coating conditions are: roller pressure of 0.1 MPa and roller speed of 10 m / min. A uniform fire extinguishing microcapsule silicone resin coating is formed on the fire-prone surface of the high-silica fiberglass cloth. Finally, allow it to stand at room temperature for 24 hours to achieve complete curing. The preparation method of fire extinguishing microcapsule silicone resin is as follows: fire extinguishing microcapsules with a particle size of 30±2µm are added to silicone resin at a mass addition ratio of 15%, and the mixture is stirred evenly by mechanical stirring. The stirring speed is set to 600rpm and the stirring time is set to 30min. Specifications of high silica fiberglass cloth: The high silica fiber linear density is 150tex, it is made by machine weaving, with a twill weave structure, a surface density of 450±5g / m², a fabric width of 1m, and a length of 100m.

[0039] S2. The expanded microsphere silicone resin is uniformly coated onto the surface of the high-silica fiberglass cloth without the fire extinguishing microcapsule silicone resin obtained in step S1 using a pressure roller method. The coating mass is 150±10 g / m². The specific coating conditions are: the pressure of the coating roller is 0.08 MPa, and the roller speed is 12 m / min, forming a uniform, incompletely cured expanded microsphere silicone resin coating on the surface of the high-silica fiberglass cloth without the fire extinguishing microcapsule silicone resin. The preparation method of expanded microsphere silica resin is as follows: expanded microspheres with a particle size of 15±2µm are added to silica resin at a mass addition ratio of 6%, and the mixture is uniformly mixed by mechanical stirring. The stirring speed is set to 600rpm and the stirring time is set to 30min.

[0040] S3. The aramid fabric is simultaneously coated onto the expanded microsphere silicone resin coating of step S2 using a pressure roller method. Under the pressure of 0.2 MPa of the pressure roller, the aramid fabric and the expanded microsphere silicone resin coating of step S2 are completely coated. Finally, the coating is allowed to stand at room temperature for 24 hours to achieve complete curing. Aramid fabric specifications and dimensions: Taihe New Material TH5108 para-aramid filament fabric, para-aramid filament linear density is 1000D, it is prepared by machine weaving process, plain weave structure, areal density is 220±5g / m², fabric width is 1m, length is 100m.

[0041] S4. Apply the UV-resistant fireproof coating to the surface of the composite aramid fabric in step S3 using a roller coating method. The coating mass is 130±10g / m². After coating, cure at room temperature to finally obtain the fire extinguishing cover material.

[0042] The formulation of the UV-resistant fireproof coating consists of: 35 parts epoxy resin emulsion, 25 parts vinyl acetate emulsion, 20 parts zinc borate, 8 parts cobalt aluminate, 5 parts nano TiO2, 6 parts deionized water, 0.5 parts dispersant (sodium polycarboxylate), 0.3 parts defoamer (organosilicon), and 0.2 parts film-forming aid (dodecyl alcohol ester).

[0043] Example 2 A fire extinguishing cover material for new energy vehicles reinforced with aramid fabric, the fire extinguishing cover material for new energy vehicles comprising a fire extinguishing microcapsule silicone resin layer, a high-silica fiberglass cloth, an expandable microsphere silicone resin layer, aramid fabric, and an anti-ultraviolet fireproof coating layer.

[0044] The preparation method of an aramid fabric-reinforced fire extinguishing cover material for new energy vehicles is as follows: S1. Apply fire extinguishing microcapsule silicone resin evenly to the fire-prone surface of high-silica fiberglass cloth using a roller coating method. The coating mass is 400±10 g / m². Specific coating conditions are: roller pressure of 0.2 MPa, roller speed of 8 m / min, forming a uniform fire extinguishing microcapsule silicone resin coating on the fire-prone surface of the high-silica fiberglass cloth. Finally, allow it to stand at room temperature for 24 hours to achieve complete curing. The preparation method of fire extinguishing microcapsule silicone resin is as follows: fire extinguishing microcapsules with a particle size of 75±2µm are added to silicone resin at a mass addition ratio of 18%, and the mixture is uniformly mixed by mechanical stirring. The stirring speed is set to 600rpm and the stirring time is set to 30min. Specifications of high silica fiberglass cloth: The high silica fiber linear density is 200 tex, it is made by machine weaving, has a twill weave structure, an areal density of 595±5 g / m², a fabric width of 1m, and a length of 100m.

[0045] S2. The expanded microsphere silicone resin is uniformly coated onto the surface of the high-silica fiberglass cloth without the fire extinguishing microcapsule silicone resin obtained in step S1 using a pressure roller method. The coating mass is 200±10 g / m². The specific coating conditions are: the pressure of the coating roller is 0.15 MPa, and the roller speed is 9 m / min, forming a uniform, incompletely cured expanded microsphere silicone resin coating on the surface of the high-silica fiberglass cloth without the fire extinguishing microcapsule silicone resin. The preparation method of expanded microsphere silica resin is as follows: expanded microspheres with a particle size of 7±2µm are added to silica resin at a mass addition ratio of 5%, and the mixture is stirred evenly by mechanical stirring at a speed of 600rpm for 30min.

[0046] S3. The aramid fabric is simultaneously coated onto the expanded microsphere silicone resin coating of step S2 using a pressure roller method. Under the pressure of 0.2 MPa of the pressure roller, the aramid fabric and the expanded microsphere silicone resin coating of step S2 are completely coated. Finally, the coating is allowed to stand at room temperature for 24 hours to achieve complete curing. Aramid fabric specifications and dimensions: Taihe New Material TH5108 para-aramid filament fabric, para-aramid filament linear density is 1000D, it is prepared by machine weaving process, plain weave structure, areal density is 220±5g / m², fabric width is 1m, length is 100m.

[0047] S4. Apply the UV-resistant fireproof coating to the surface of the composite aramid fabric in step S3 using a roller method. The coating mass is 190±10g / m². After coating, cure at room temperature to finally obtain the fire extinguishing cover material.

[0048] The formulation of the UV-resistant fireproof coating consists of: 35 parts epoxy resin emulsion, 25 parts vinyl acetate emulsion, 20 parts zinc borate, 8 parts cobalt aluminate, 5 parts nano TiO2, 6 parts deionized water, 0.5 parts dispersant (sodium polycarboxylate), 0.3 parts defoamer (organosilicon), and 0.2 parts film-forming aid (dodecyl alcohol ester).

[0049] Example 3 A fire extinguishing cover material for new energy vehicles reinforced with aramid fabric, the fire extinguishing cover material for new energy vehicles comprising a fire extinguishing microcapsule silicone resin layer, a high-silica fiberglass cloth, an expandable microsphere silicone resin layer, aramid fabric, and an anti-ultraviolet fireproof coating layer.

[0050] The preparation method of an aramid fabric-reinforced fire extinguishing cover material for new energy vehicles is as follows: S1. Apply fire extinguishing microcapsule silicone resin evenly to the fire-prone surface of high-silica fiberglass cloth using a roller coating method. The coating mass is 490±10 g / m². Specific coating conditions are: roller pressure of 0.3 MPa, roller speed of 5 m / min, forming a uniform fire extinguishing microcapsule silicone resin coating on the fire-prone surface of the high-silica fiberglass cloth. Finally, allow it to stand at room temperature for 24 hours to achieve complete curing. The preparation method of fire extinguishing microcapsule silicone resin is as follows: fire extinguishing microcapsules with a particle size of 12±2µm are added to silicone resin at a mass addition ratio of 20%, and the mixture is stirred evenly by mechanical stirring. The stirring speed is set to 600rpm and the stirring time is set to 30min. Specifications of high silica fiberglass cloth: The high silica fiber linear density is 180 tex, it is made by machine weaving, has a satin weave structure, an areal density of 305±5 g / m², a fabric width of 1m, and a length of 100m.

[0051] S2. The expanded microsphere silicone resin is uniformly coated onto the surface of the high-silica fiberglass cloth without the fire extinguishing microcapsule silicone resin obtained in step S1 using a pressure roller method. The coating mass is 240±10 g / m². The specific coating conditions are: the pressure of the coating roller is 0.2 MPa, and the roller speed is 6 m / min, forming a uniform, incompletely cured expanded microsphere silicone resin coating on the surface of the high-silica fiberglass cloth without the fire extinguishing microcapsule silicone resin. The preparation method of expanded microsphere silica resin is as follows: fire extinguishing microcapsules with a particle size of 48±2µm are added to silica resin at a mass addition ratio of 10%, and the mixture is stirred evenly by mechanical stirring at a speed of 600rpm for a time of 30min.

[0052] S3. The aramid fabric is simultaneously coated onto the expanded microsphere silicone resin coating of step S2 using a pressure roller method. Under the pressure of 0.2 MPa of the pressure roller, the aramid fabric and the expanded microsphere silicone resin coating of step S2 are completely coated. Finally, the coating is allowed to stand at room temperature for 24 hours to achieve complete curing. Aramid fabric specifications and dimensions: Taihe New Material TH5108 para-aramid filament fabric, para-aramid filament linear density is 1000D, it is prepared by machine weaving process, plain weave structure, areal density is 220±5g / m², fabric width is 1m, length is 100m.

[0053] S4. Apply the UV-resistant fireproof coating to the surface of the composite aramid fabric in step S3 using a roller coating method. The coating mass is 110±10g / m². After coating, cure at room temperature to finally obtain the fire extinguishing cover material.

[0054] The formulation of the UV-resistant fireproof coating consists of: 35 parts epoxy resin emulsion, 25 parts vinyl acetate emulsion, 20 parts zinc borate, 8 parts cobalt aluminate, 5 parts nano TiO2, 6 parts deionized water, 0.5 parts dispersant (sodium polycarboxylate), 0.3 parts defoamer (organosilicon), and 0.2 parts film-forming aid (dodecyl alcohol ester).

[0055] Comparative Example 1 To verify the performance advantages of the aramid fabric-reinforced fire extinguishing cover material for new energy vehicles described in this invention, Comparative Example 1 was set up. Comparative Example 1 uses commercially available fire extinguishing cover material for new energy vehicles. Its main structure is a high-silica fiberglass cloth (area density ≈ 700 g / ㎡) with a surface coated with ordinary flame-retardant silicone coating. Although this material has certain flame-retardant properties, it lacks active fire extinguishing function and has poor impact resistance.

[0056] Comparative Example 2 The fire extinguishing cover material was prepared using the same method as in Example 1, except that fire extinguishing microcapsules were not added in step S1 of Comparative Example 2. Instead, silicone resin was directly coated on the fire-prone side surface of the high-silica fiberglass cloth. Other process conditions were the same as in Example 1.

[0057] Comparative Example 3 The fire extinguishing cover material was prepared using the same method as in Example 1, except that in step S1 of Comparative Example 3, the mass content of fire extinguishing microcapsules in the fire extinguishing microcapsule silicone resin was 30% (higher than the dosage ratio specified in this invention), and other process conditions were the same as in Example 1.

[0058] Comparative Example 4 The fire extinguishing cover material was prepared using the same method as in Example 1, except that: in step S2 of Comparative Example 4, expanded microspheres were not added, but silicone resin was directly coated on the other surface of the high-silica fiberglass cloth. Other process conditions were the same as in Example 1.

[0059] Comparative Example 5 The fire extinguishing cover material was prepared using the same method as in Example 1, except that in step S2 of Comparative Example 5, the mass content of expanded microspheres in the expanded microsphere silicone resin was 20% (higher than the dosage ratio specified in this invention), and other process conditions were the same as in Example 1.

[0060] Comparative Example 6 The fire extinguishing cover material was prepared using the same method as in Example 1, except that the positions of the high-silica fiberglass cloth and aramid fabric were changed in Comparative Example 6. The specific preparation process is as follows: S1. Apply fire extinguishing microcapsule silicone resin evenly to the fire-prone surface of aramid fabric using a roller coating method. The coating mass is 300±10 g / m². Specific coating conditions are: roller pressure of 0.1 MPa, roller speed of 10 m / min, forming a uniform fire extinguishing microcapsule silicone resin coating on the fire-prone surface of the aramid fabric. Finally, allow it to stand at room temperature for 24 hours to achieve complete curing. The preparation method of the fire extinguishing microcapsule silicone resin is the same as in Example 1; Aramid fabric specifications and dimensions: same as in Example 1.

[0061] S2. The expanded microsphere silicone resin is uniformly coated onto the surface of the high-silica fiberglass cloth without fire extinguishing microcapsule silicone resin obtained in step S1 using a pressure roller method. The coating mass is 150±10 g / m². The specific coating conditions are: the pressure of the coating roller is 0.08 MPa, and the roller speed is 12 m / min, forming a uniform, incompletely cured expanded microsphere silicone resin coating on the surface of the aramid fabric without fire extinguishing microcapsule silicone resin. The preparation method of the expanded microsphere silicone resin is the same as in Example 1.

[0062] S3. The high-silica fiberglass cloth is simultaneously applied to the expanded microsphere silicone resin coating of step S2 using a pressure roller method. Under the pressure of 0.2MPa of the pressure roller, the aramid fabric and the expanded microsphere silicone resin coating of step S2 are completely bonded together. Finally, it is left to stand at room temperature for 24 hours to achieve complete curing. The specifications and dimensions of the high-silica fiberglass cloth are the same as in Example 1.

[0063] S4. Apply the UV-resistant fireproof coating to the surface of the composite high-silica fiberglass cloth in step S3 using a roller method. The coating mass is 130±10g / m². After coating, cure at room temperature to finally obtain the fire extinguishing cover material.

[0064] The formulation of the UV-resistant fireproof coating is the same as in Example 1.

[0065] Comparative Example 7 The fire extinguishing cover material was prepared using the same method as in Example 1, except that the positions of the fire extinguishing microcapsule silicone resin layer and the expanded microsphere silicone resin layer were changed in Comparative Example 7. The specific preparation process is as follows: S1. The expanded microsphere silicone resin is uniformly coated onto the fire-prone surface of high-silica fiberglass cloth using a pressure roller method, with a coating mass of 150±10 g / m². Specific coating conditions are: pressure of the coating roller is 0.08 MPa, and roller speed is 12 m / min. A uniform expanded microsphere silicone resin coating is formed on the surface of the high-silica fiberglass cloth that is not coated with fire-extinguishing microcapsule silicone resin. Finally, it is allowed to stand at room temperature for 24 hours to achieve complete curing. The preparation method of the expanded microsphere silicone resin is the same as in Example 1.

[0066] The specifications and dimensions of the high-silica fiberglass cloth are the same as in Example 1.

[0067] S2. The fire extinguishing microcapsule silicone resin is uniformly coated onto the surface of the high-silica fiberglass cloth without the expanded microsphere silicone resin obtained in step S1 using a pressure roller method. The coating mass is 300±10 g / m². The specific coating conditions are: the pressure of the coating roller is 0.1 MPa, and the roller speed is 10 m / min, forming a uniform, incompletely cured fire extinguishing microcapsule silicone resin coating on the fire-prone side of the high-silica fiberglass cloth. The preparation method of the fire extinguishing microcapsule silicone resin is the same as in Example 1.

[0068] S3. The aramid fabric is simultaneously applied to the fire extinguishing microcapsule silicone resin coating of step S2 using a pressure roller method. Under the condition of a pressure roller pressure of 0.2MPa, the aramid fabric and the fire extinguishing microcapsule silicone resin coating of step S2 are completely bonded together. Finally, it is left to stand at room temperature for 24 hours to achieve complete curing. Aramid fabric specifications and dimensions: same as in Example 1.

[0069] S4. Apply the UV-resistant fireproof coating to the surface of the composite aramid fabric in step S3 using a roller coating method. The coating mass is 130±10g / m². After coating, cure at room temperature to finally obtain the fire extinguishing cover material.

[0070] The formulation of the UV-resistant fireproof coating is the same as in Example 1.

[0071] The fire extinguishing cover materials prepared in the above embodiments and comparative examples were subjected to performance tests. The specific test results are shown in Table 1 below. The test methods involved are as follows: Rapid fire extinguishing performance test: Based on the fire characteristics of thermal runaway of new energy vehicle batteries, a propane torch (flame temperature 1000℃±50℃, flame height 10cm, area 0.04㎡) was used to simulate the battery ignition source. The fire extinguishing cover material was cut into 500mm×500mm samples and covered on the surface of the burning simulated battery ignition source. The time (s) from the completion of covering to the complete extinguishing of the flame was recorded.

[0072] Thermal insulation test: Take a fire extinguishing cover material sample with a size of 300mm×300mm, use a high-temperature flame heat source (1000℃±50℃) to continuously heat the side of the sample near the fire, use a thermocouple temperature sensor to measure the temperature at the center point of the sample far from the fire, continuously monitor the temperature change for 5 minutes, and record the highest temperature.

[0073] Flame retardant performance test: Take a fire blanket material sample with a size of 200mm×100mm, and burn the sample vertically with a propane torch. Record the flame combustion test results at 1000℃ / 2h, and observe whether the sample is damaged or penetrated by flame.

[0074] Explosion-proof and impact-resistant performance test: Simulate the thermal runaway explosion impact of a new energy vehicle battery module (refer to "UL 2596 Battery System Thermal Runaway Protection Test"). Cover the simulated explosion device (containing 50g of overcharged lithium-ion battery) with the material, observe and record whether the material cracks or whether there is any splash penetration.

[0075] Table 1 Performance Test Results As can be seen from the data in the table above, the fire extinguishing cover materials prepared by the method described in Examples 1-3 are superior in terms of fire extinguishing performance, heat insulation protection, and impact and explosion resistance. Under a high temperature environment of 1000℃, the back temperature of the fire extinguishing cover material described in this invention remains below 200℃ within 5 minutes, while the back temperature of the material in Comparative Example 1 rises to above 500℃ within 2 minutes, failing to effectively block heat. In the simulated battery explosion experiment, the material of this invention completely covers the fire source and prevents splashing, while the material in Comparative Example 1 tears due to insufficient strength, causing the fire to spill out.

[0076] A comparison of the experimental results from Comparative Example 2 and Example 1 shows that without the addition of fire extinguishing microcapsules, the fire extinguishing performance is significantly reduced, and the thermal insulation performance is also significantly decreased. This is because the absence of fire extinguishing microcapsules causes the material to lose its ability to rapidly rupture at around 120°C and release perfluorohexanone and ethyl nonafluorobutyl ether fire extinguishing agents, thus failing to achieve active suppression in the early stages of a fire. Simultaneously, due to the lack of rapid cooling and suffocation effects from the fire extinguishing agents, the continued combustion of the flames leads to a large accumulation and rapid transfer of heat. This causes the initial heat load, which should have been borne by the fire extinguishing agents, to be completely transferred to the insulation layer, resulting in increased overall insulation pressure and a rise in the temperature on the back side.

[0077] A comparison of the experimental results from Comparative Example 3 and Example 1 shows that if the proportion of fire extinguishing microcapsules added is too high (30%, exceeding the optimized range of 15%-20%), the fire extinguishing efficiency decreases and becomes uneven. Simultaneously, the integrity of the coating structure is compromised, leading to peeling at high temperatures. This is because excessive microcapsule content severely disrupts the continuity of the silicone resin matrix, resulting in decreased coating cohesion and weakened adhesion. Under flame conditions, premature concentrated rupture of the microcapsules may cause localized stress concentration and peeling of the coating. Furthermore, the unstable coating structure also affects the uniform diffusion and barrier of heat, leading to increased backside temperature and decreased explosion-proof and impact-resistant performance.

[0078] A comparison of the experimental results of Comparative Example 4 and Example 1 shows that without the addition of expanded microspheres, the thermal insulation performance is significantly reduced (temperature on the far-field side reaches 383°C), and the aramid fabric and the UV-resistant coating are damaged at high temperatures. This is because the absence of expanded microspheres prevents the material from forming an effective porous expanded thermal insulation layer at high temperatures (>160°C). Heat cannot be effectively blocked and dissipated, and is rapidly transferred to the outer aramid fabric layer, causing its temperature to exceed its tolerance limit and resulting in damage, thus affecting the integrity of the overall structure.

[0079] A comparison of the experimental results from Comparative Example 5 and Example 1 shows that if the proportion of expanded microspheres added is too high (20%, exceeding the optimized range of 5%-10%), it can easily lead to the aramid fabric breaking and falling off. This is because excessive expanded microspheres cause the resin matrix to be overly diluted, making the coating brittle and reducing its toughness. During high-temperature expansion, it is prone to cracking or peeling off from the substrate. Without the outer aramid fabric's explosion-proof and impact-resistant properties, the remaining high-silica fiberglass cloth hardens and becomes brittle under prolonged high-temperature combustion conditions, leading to breakage under high temperature and impact.

[0080] A comparison of the experimental results from Comparative Example 6 and Example 1 shows that if the positions of the high-silica fiberglass cloth and the aramid fabric are changed, the aramid fabric is easily burned through. This is because the aramid fabric, located on the inner side, directly bears the high temperature, and its temperature resistance limit (approximately 500°C) is far lower than that of the high-silica fiberglass cloth (>1000°C), causing it to fail rapidly under sustained high temperatures. Meanwhile, although the outer high-silica fiberglass cloth is heat-resistant, it lacks the high-strength support of the aramid fabric, making it prone to overall structural deformation under explosive impact, leading to the collapse of the protective system.

[0081] A comparison of the experimental results from Comparative Example 7 and Example 1 shows that if the positions of the fire extinguishing microcapsule silicone resin layer and the expanding microsphere silicone resin layer are changed, the fire extinguishing function completely fails, and the heat insulation performance decreases. This is because some of the fire extinguishing microcapsules on the outer side rupture prematurely under direct flame impact, resulting in the extinguishing agent failing to be effectively released at the base of the fire source and being largely lost. Simultaneously, the inner expanding microsphere layer expands prematurely due to direct contact with high temperatures and may be ablated, reducing its subsequent heat insulation capacity. This incorrect layering sequence prevents both the fire extinguishing and heat insulation functions from working synergistically as designed.

[0082] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are exhaustively listed. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0083] For those skilled in the art, various modifications and improvements can be made without departing from the concept of the present invention, and these modifications and improvements are all within the scope of protection of the present invention. The scope of protection of the present invention is defined by the appended claims.

Claims

1. A material for fire extinguishing covers of new energy vehicles reinforced with aramid fabric, characterized in that, The fire extinguishing cover material, from the inside out, includes: a fire extinguishing microcapsule silicone resin coating, a high-silica fiberglass cloth, an expanded microsphere silicone resin coating, an aramid fabric, and an anti-ultraviolet fireproof coating layer. The fire extinguishing microcapsule silicone resin coating comprises fire extinguishing microcapsules and silicone resin, wherein the fire extinguishing microcapsules are added to the fire extinguishing microcapsule silicone resin at a mass ratio of 15%-20%. The expanded microsphere silicone resin coating comprises expanded microspheres and silicone resin, wherein the expanded microspheres are added to the expanded microsphere silicone resin at a mass ratio of 5%-10%. The fire extinguishing microcapsule includes a fire extinguishing agent and a coating material; The extinguishing agent includes perfluorohexanone and ethyl nonafluorobutyl ether; The coating material is polystyrene or polymethyl methacrylate; The expanded microspheres are PG40 type expanded microspheres.

2. The aramid fabric reinforced fire extinguishing cover material for new energy vehicles according to claim 1, characterized in that, The fire extinguishing microcapsules have a particle size of 10µm-80µm. The surface of the fire extinguishing microcapsules is treated with a silane coupling agent and then added to silicone resin to form the fire extinguishing microcapsule silicone resin.

3. The aramid fabric-reinforced fire extinguishing cover material for new energy vehicles according to claim 1, characterized in that, The high-silica glass fiber cloth is made by weaving high-silica glass fiber yarn to obtain plain weave, twill weave or satin weave structure; The high-silica glass fiber yarn has a SiO2 content of ≥96% and a linear density of 150tex-200tex. The areal density of the high-silica fiberglass cloth is 300 g / m². 2 -600g / m 2 .

4. The aramid fabric-reinforced fire extinguishing cover material for new energy vehicles according to claim 1, characterized in that, The aramid fabric is an aramid fabric with a plain weave, twill weave, or satin weave structure made by machine weaving para-aramid filament yarn. The linear density of para-aramid filament yarn is 600D-1500D; The areal density of the aramid fabric is 150 g / m³. 2 -300g / m 2 .

5. The aramid fabric-reinforced fire extinguishing cover material for new energy vehicles according to claim 1, characterized in that, The UV-resistant fire-retardant coating layer includes a film-forming component, a flame-retardant component, and a UV-resistant component; The film-forming component includes epoxy resin emulsion and vinyl acetate emulsion; the flame-retardant component includes zinc borate and cobalt aluminate; and the UV-resistant component includes nano-TiO2.

6. A method for preparing an aramid fabric-reinforced fire extinguishing cover material for new energy vehicles according to any one of claims 1-5, characterized in that, The preparation method is as follows: S1. The fire extinguishing microcapsule silicone resin is uniformly coated on the fire-prone side surface of the high-silica fiberglass cloth and cured to form a fire extinguishing microcapsule silicone resin coating. S2. The expanded microsphere silicone resin is uniformly coated on the other surface of the high silica fiber cloth in step S1 to form an expanded microsphere silicone resin coating. S3. The aramid fabric is attached to the expanded microsphere silicone resin coating of step S2 and cured. S4. The UV-resistant fireproof coating is uniformly applied to the surface of the aramid fabric in step S3 to form a UV-resistant fireproof coating layer. Finally, after curing treatment, the fire extinguishing cover material is obtained.

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