A aramid aerogel fireproof and explosion-proof bag material for mobile phones, its preparation method and application

Abstract

This invention relates to the field of composite materials technology, specifically to an aramid aerogel fireproof and explosion-proof bag material for mobile phones, its preparation method, and its application. The fireproof and explosion-proof bag material comprises, from the inside out, a fireproof layer, a heat insulation layer, and a support layer. The fireproof layer is selected from at least one of meta-aramid and para-aramid. The heat insulation layer is a silica-hydroxyl-functionalized polyimide aerogel. The support layer is selected from at least one of meta-aramid and para-aramid. An isocyanate curing agent solution is coated between each layer of the fireproof and explosion-proof bag material. After the layers are composited, the material is heated and dried to obtain the fireproof and explosion-proof bag material. The mass concentration of the isocyanate curing agent in the isocyanate curing agent solution is 15%-30%. The flexible aramid aerogel fireproof and explosion-proof bag material and its preparation method of this invention can effectively improve the bag's strength and flame-retardant and heat-insulating capabilities.

Description

Technical Field

[0001] This invention relates to an aramid aerogel fireproof and explosion-proof bag material for mobile phones, its preparation method, and its application, belonging to the field of composite material technology. Background Technology

[0002] Most mobile phones on the market use lithium-ion batteries. These batteries enable phones to support various functions such as gaming, video streaming, and online shopping. This requires lithium-ion batteries to have extreme performance characteristics such as fast charging and discharging, and good cycle life. This, in turn, greatly increases the risk of smoke, fire, and explosion during charging, discharging, or storage. To address potential safety issues with mobile phones and protect user safety, explosion-proof mobile phone bags are designed to limit the impact of battery explosions or fires through special materials and structural designs.

[0003] Chinese patent CN213487400U proposes a structure consisting of a fireproof cloth fireproof layer and an aramid fiber cloth explosion-proof layer, from the inside out. However, its fireproof layer has low mechanical strength and limited bonding force with the explosion-proof layer. During the fire and explosion of lithium-ion batteries, the surface is easily worn or even torn, failing to provide sufficient support and protection, and thus cannot achieve excellent explosion-proof function. Furthermore, its fireproof layer does not have the function of absorbing heat, so the large amount of heat generated during thermal failure poses a risk of heat spread. Chinese patent CN215751248U discloses an aerogel foam pad for heat insulation and fire protection of power batteries, including an encapsulation film layer I, a fireproof layer I, an aerogel heat insulation layer, a fireproof layer II, and an encapsulation film layer II. The aerogel heat insulation layer is located between the fireproof layer I and the fireproof layer II. The outer surface of the fireproof layer I is provided with the encapsulation film layer I, and the outer surface of the fireproof layer II is provided with the encapsulation film layer II. The layers are bonded together by hot pressing. The layer structure of this patent is relatively complex, and the interlayer peel strength is low. Chinese patent CN 218985997 U discloses a composite fabric for fire blankets used in new energy vehicles, comprising a surface layer, a middle layer, and an inner layer. The surface and inner layers are made of organic flame-retardant materials, while the middle layer is made of inorganic flame-retardant materials. The fabric is formed into a layered structure using woven or non-woven methods. Due to its organic-inorganic-organic three-layer composite structure, and the use of hot melt adhesive to bond the layers, the organic-inorganic interface has low compatibility, making it difficult to achieve good bonding strength and heat insulation. Therefore, developing a fireproof and explosion-proof mobile phone bag material with excellent fire and explosion resistance, simple structure, and high interlayer peel strength is of significant value. Summary of the Invention

[0004] This invention addresses the shortcomings of existing technologies by providing an aramid aerogel fireproof and explosion-proof bag material for mobile phones, its preparation method, and its application. The aramid aerogel fireproof and explosion-proof bag material can effectively reduce the thermal conductivity of the bag body and improve its fire resistance, heat insulation performance, and interlayer bonding strength.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: an aramid aerogel mobile phone fireproof and explosion-proof bag material, wherein the fireproof and explosion-proof bag material includes a fireproof layer, a heat insulation layer and a support layer from the inside to the outside;

[0006] The fireproof layer is selected from at least one of meta-aramid and para-aramid; the heat insulation layer is silica-hydroxyl-functionalized polyimide aerogel; the support layer is selected from at least one of meta-aramid and para-aramid.

[0007] The layers of the fireproof and explosion-proof bag material are coated with an isocyanate curing agent solution. After the layers are composited, the fireproof and explosion-proof bag material is obtained by heating and drying.

[0008] Furthermore, the preparation method of the silica-hydroxyl-functionalized polyimide aerogel includes the following steps:

[0009] A mixture is prepared by mixing aromatic dianhydride, hydroxy-functionalized aromatic diamine and N-methylpyrrolidone solution, with the molar ratio of aromatic dianhydride to hydroxy-functionalized diamine controlled at 10:(9-9.5).

[0010] An N-methylpyrrolidone solution of an aromatic triamine and silica aerogel powder are added to the mixture and mixed evenly. A dehydrating agent and a catalyst are added, and after mixing evenly, the mixture is processed into shape and allowed to stand to gel. The molar ratio of the aromatic triamine to the aromatic dianhydride is (0.35-0.7):10, and the molar ratio of the dehydrating agent to the aromatic dianhydride is (7-8):1.

[0011] The gel was solvent-exchanged in N-methylpyrrolidone and / or acetone solution for 1-5 days, dried with supercritical carbon dioxide, and then vacuum dried at 40-80℃ to obtain silica-hydroxyl-functionalized polyimide aerogel.

[0012] Furthermore, the aromatic dianhydride is selected from one or more of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, pyromellitic dianhydride, 3,3',4,4'-diphenylmethyl ether tetracarboxylic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-triphenyl diether tetracarboxylic dianhydride, and 4,4'-(hexafluoroisopropyl)bisphthalic acid dianhydride;

[0013] The hydroxyl-functionalized aromatic diamine is 3,3'-dihydroxybenzidine;

[0014] The aromatic triamine is selected from one or more of 1,3,5-triaminophenoxybenzene and 1,3,5-triaminobenzene;

[0015] The dehydrating agent is acetic anhydride or propionic anhydride;

[0016] The catalyst is selected from one or more of pyridine, isoquinoline and β-methylpyridine;

[0017] The silica aerogel powder has a particle size of 1-20 μm and a density of 0.1-0.12 g / cm³. 3 In the silica-hydroxy functionalized polyimide aerogel, the mass percentage of silica aerogel powder is 10-40%, and the mass percentage of polyimide is 60-90%.

[0018] Furthermore, the isocyanate curing agent solution is a solution formed by dissolving the isocyanate curing agent in an organic solvent, the mass concentration of the isocyanate curing agent in the isocyanate curing agent solution is 15%-30%, and the functionality of the isocyanate groups in the isocyanate curing agent is not less than 2.

[0019] Furthermore, the organic solvent is any one of benzene, toluene, chlorobenzene, nitrobenzene, and acetone.

[0020] Furthermore, the isocyanate curing agent is selected from at least one of diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, toluene diisocyanate, isophorone diisocyanate, and triphenylmethane triisocyanate.

[0021] Furthermore, the fireproof layer has a thickness of 0.5-5mm, the heat insulation layer has a thickness of 0.02-2mm, and the support layer has a thickness of 0.5-5mm.

[0022] Furthermore, based on the total mass of the fireproof and explosion-proof bag material (100%), the mass of the isocyanate curing agent is 0.1-5%.

[0023] Furthermore, the heating and drying process conditions are as follows: heating temperature is 40-120℃, and vacuum drying is performed for 12-48 hours.

[0024] Preferably, the fireproof layer is meta-aramid; the support layer is para-aramid.

[0025] This invention also discloses a method for preparing an aramid aerogel fireproof and explosion-proof mobile phone bag material, wherein the preparation method is as follows:

[0026] An isocyanate curing agent solution is coated onto the support layer, and the heat insulation layer is placed on the support layer coated with the isocyanate curing agent solution.

[0027] Then, an isocyanate curing agent solution is coated on the heat insulation layer, and the fireproof layer is placed on the heat insulation layer to prepare a composite of fireproof layer-heat insulation layer-support layer;

[0028] The composite of the fireproof layer-heat insulation layer-support layer is heated and dried to obtain the aramid aerogel mobile phone fireproof and explosion-proof bag material.

[0029] This invention also discloses the application of an aramid aerogel fireproof and explosion-proof bag material for mobile phones. The aramid aerogel fireproof and explosion-proof bag material is used in a fireproof and explosion-proof bag for mobile phones, with the fireproof layer serving as the inner layer of the fireproof and explosion-proof bag for mobile phones and the support layer serving as the outer layer of the fireproof and explosion-proof bag for mobile phones.

[0030] The beneficial effects of this invention are:

[0031] The innermost fireproof layer of the fireproof and explosion-proof bag material of this invention is made of meta-aramid or para-aramid, which has excellent flame retardancy, high temperature resistance, insulation, and chemical stability. It can effectively prevent the fire from spreading after a mobile phone catches fire or explodes and provides a good buffering effect. The heat insulation layer uses silica-hydroxyl-modified polyimide aerogel, which has significant advantages over single inorganic materials or organic polymer aerogels. First, the large specific surface area of ​​silica-hydroxyl-modified polyimide aerogel can effectively absorb the heat released by thermal failure and reduce the external temperature of the explosion-proof bag. Second, polyimide has an organic structure and good compatibility with organic fireproof layers and support layers. Third, after polyimide is combined with silica, it can overcome the limitations of high-temperature conditions (such as exceeding 20°C). The drawback of high volume shrinkage at 00°C is overcome by further improving heat resistance. Finally, the abundant hydroxyl structure provides more bonding sites for the curing agent, resulting in a large number of chemical bonds between the fireproof layer and the insulation layer, and between the support layer and the insulation layer, significantly improving the interlayer bonding force. The support layer uses para-aramid or meta-aramid. Aramid fibers have advantages such as fire resistance, flame retardancy, heat resistance, and wear resistance, providing excellent support and fire resistance for the fireproof and explosion-proof mobile phone bag. An isocyanate curing agent is coated between the fireproof layer, the insulation layer, and the support layer. After vacuum heat treatment, the isocyanate forms chemical bonds with the terminal carboxyl / terminal amino groups of aramid and the terminal amino and hydroxyl groups of polyimide, which improves the bonding force between the fireproof layer, the insulation layer, and the support layer, further enhancing the mechanical strength of the bag.

[0032] The fireproof and explosion-proof bag material described in this invention provides a portable device with both fireproof and explosion-proof functions. On the one hand, it enhances the adhesion between materials such as the fireproof layer, heat insulation layer, and support layer through chemical bonding, thereby ensuring the mechanical strength of the bag and effectively suppressing the impact of thermal failure of the mobile phone, controlling the explosion effect within the explosion-proof bag. On the other hand, the heat insulation layer absorbs the heat generated during thermal failure, reducing the external temperature of the explosion-proof bag and achieving a heat insulation effect. This reduces property damage and personal injury caused by lithium-ion battery fires and explosions, improving the safety of mobile phone use. Attached Figure Description

[0033] Figure 1This is a structural schematic diagram of the fireproof and explosion-proof bag for mobile phones described in the embodiment;

[0034] Figure 2 This is a schematic diagram of the layered structure of the fireproof and explosion-proof bag material described in the embodiment;

[0035] In the diagram, 1 is the fireproof layer; 2 is the heat insulation layer; 3 is the support layer; 4 is the bag body; 5 is the first meta-aramid flame-retardant hook and loop fastener; 6 is the second meta-aramid flame-retardant hook and loop fastener; and 7 is the carrying handle. Detailed Implementation

[0036] 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.

[0037] 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.

[0038] A fireproof and explosion-proof mobile phone bag material made of aramid aerogel, wherein the fireproof and explosion-proof bag material includes a fireproof layer, a heat insulation layer and a support layer from the inside out;

[0039] The fireproof layer is selected from at least one of meta-aramid and para-aramid; the heat insulation layer is silica-hydroxyl-functionalized polyimide aerogel; the support layer is selected from at least one of meta-aramid and para-aramid.

[0040] The layers of the fireproof and explosion-proof bag material are coated with an isocyanate curing agent solution. After the layers are composited, the fireproof and explosion-proof bag material is obtained by heating and drying.

[0041] Specifically, the preparation method of the silica-hydroxyl-functionalized polyimide aerogel includes the following steps:

[0042] A mixture is prepared by mixing aromatic dianhydride, hydroxy-functionalized aromatic diamine and N-methylpyrrolidone solution, with the molar ratio of aromatic dianhydride to hydroxy-functionalized diamine controlled at 10:(9-9.5).

[0043] An N-methylpyrrolidone solution of an aromatic triamine and silica aerogel powder are added to the mixture and mixed evenly. A dehydrating agent and a catalyst are added, and after mixing evenly, the mixture is processed into shape and allowed to stand to gel. The molar ratio of the aromatic triamine to the aromatic dianhydride is (0.35-0.7):10, and the molar ratio of the dehydrating agent to the aromatic dianhydride is (7-8):1. The molar amounts of the catalyst and the dehydrating agent are equal.

[0044] The gel was solvent-exchanged in N-methylpyrrolidone and / or acetone solution for 1-5 days, dried with supercritical carbon dioxide, and then vacuum dried at 40-80℃ to obtain silica-hydroxyl-functionalized polyimide aerogel.

[0045] Specifically, the aromatic dianhydride is selected from one or more of the following: 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, pyromellitic dianhydride, 3,3',4,4'-diphenylmethyl ether tetracarboxylic acid dianhydride, 3,3',4,4'-benzophenone tetracarboxylic acid dianhydride, 3,3',4,4'-triphenyl diether tetracarboxylic acid dianhydride, and 4,4'-(hexafluoroisopropyl)bisphthalic acid dianhydride.

[0046] The hydroxyl-functionalized aromatic diamine is 3,3'-dihydroxybenzidine;

[0047] The aromatic triamine is selected from one or more of 1,3,5-triaminophenoxybenzene and 1,3,5-triaminobenzene;

[0048] The dehydrating agent is acetic anhydride or propionic anhydride;

[0049] The catalyst is selected from one or more of pyridine, isoquinoline and β-methylpyridine;

[0050] The silica aerogel powder has a particle size of 1-20 μm and a density of 0.1-0.12 g / cm³. 3 In the silica-hydroxy functionalized polyimide aerogel, the mass percentage of silica aerogel powder is 10-40%, and the mass percentage of polyimide is 60-90%.

[0051] Specifically, the isocyanate curing agent solution is a solution formed by dissolving the isocyanate curing agent in an organic solvent, the mass concentration of the isocyanate curing agent in the isocyanate curing agent solution is 15%-30%, and the functionality of the isocyanate groups in the isocyanate curing agent is not less than 2.

[0052] Specifically, the organic solvent is any one of benzene, toluene, chlorobenzene, nitrobenzene, and acetone.

[0053] Specifically, the isocyanate curing agent is selected from at least one of diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, toluene diisocyanate, isophorone diisocyanate, and triphenylmethane triisocyanate.

[0054] Specifically, the fireproof layer has a thickness of 0.5-5mm, the heat insulation layer has a thickness of 0.02-2mm, and the support layer has a thickness of 0.5-5mm. Within this thickness range, the fireproof and explosion-proof bag material has moderate softness and hardness, making it more suitable for the processing and preparation of explosion-proof bags.

[0055] More preferably, the thickness of the heat insulation layer is h The unit is mm; the mass concentration of the isocyanate curing agent in the isocyanate curing agent solution is c The unit is %; therefore, the relationship between the thickness of the insulation layer and the concentration of the isocyanate curing agent solution is: c = c 0 ±1, c 0 =2.5 h +15; Under these conditions, fireproof and explosion-proof bag materials with superior mechanical and thermal insulation properties can be obtained.

[0056] More preferably, when the mass proportion of polyimide in the insulation layer is relatively large, a relatively thick insulation layer can be used, so that the insulation layer can maintain good viscosity performance and have good insulation effect.

[0057] Specifically, the total mass of the fireproof and explosion-proof bag material is 100%, and the mass of the isocyanate curing agent is 0.1-5%.

[0058] Specifically, the heating and drying process conditions are as follows: heating temperature is 40-120℃, and vacuum drying is performed for 12-48 hours.

[0059] Preferably, in the fireproof and explosion-proof bag material, the isocyanate curing agent between the heat insulation layer and the support layer (hereinafter referred to as: the first curing agent) is 0.05-3% of the total mass of the fireproof and explosion-proof bag material, and the isocyanate curing agent between the fireproof layer and the heat insulation layer (hereinafter referred to as: the second curing agent) is 0.05-2% of the total mass of the fireproof and explosion-proof bag material; and the difference between the mass content of the first curing agent and the mass content of the second curing agent is not greater than 1%.

[0060] More preferably, when the mass percentage of isocyanate curing agent (the total amount of the first curing agent and the second curing agent) in the total mass of the fireproof and explosion-proof bag material is ≥0.1% and <1.5%, the heating temperature is ≥40℃ and <60℃; when the mass percentage of isocyanate curing agent (the total amount of the first curing agent and the second curing agent) in the total mass of the fireproof and explosion-proof bag material is ≥1.5% and ≤5%, the heating temperature is ≥60℃ and ≤120℃. When the coating mass of isocyanate curing agent is small, heating and drying at a relatively low temperature is beneficial for the isocyanate curing agent to react fully and avoids the isocyanate curing agent from denaturing due to excessive heat, thereby affecting the quality of the final product; when the coating mass of isocyanate curing agent is large, heating and drying at a relatively high temperature is beneficial for the rapid reaction of the isocyanate curing agent and improves production and processing efficiency.

[0061] Preferably, the fireproof layer is meta-aramid, and the support layer is para-aramid. Because the fireproof layer is the innermost layer, meta-aramid has higher fire resistance and corrosion resistance. If the battery malfunctions and leaks electrolyte, the meta-aramid material can play a good blocking role. The outermost support layer is made of para-aramid, which has higher wear resistance and is more conducive to the long-term use of the fireproof and explosion-proof mobile phone bag.

[0062] A method for preparing an aramid aerogel fireproof and explosion-proof mobile phone bag material, wherein the preparation method comprises:

[0063] An isocyanate curing agent solution is coated onto the support layer, and the heat insulation layer is placed on the support layer coated with the isocyanate curing agent solution.

[0064] Then, an isocyanate curing agent solution is coated on the heat insulation layer, and the fireproof layer is placed on the heat insulation layer to prepare a composite of fireproof layer-heat insulation layer-support layer;

[0065] The composite of the fireproof layer-heat insulation layer-support layer is heated and dried to obtain the aramid aerogel mobile phone fireproof and explosion-proof bag material.

[0066] An application of an aramid aerogel fireproof and explosion-proof bag material for mobile phones, wherein the aramid aerogel fireproof and explosion-proof bag material is used in a fireproof and explosion-proof bag for mobile phones, wherein the fireproof layer serves as the inner layer of the fireproof and explosion-proof bag for mobile phones, and the support layer serves as the outer layer of the fireproof and explosion-proof bag for mobile phones.

[0067] The raw material sources in the following embodiments and comparative examples of this invention are as follows. Unless otherwise specified, all other raw materials were obtained through ordinary commercial channels.

[0068] I. Raw materials involved in the examples and comparative examples:

[0069] (1) Meta-aramid: Suzhou Hengsian Protective Technology Co., Ltd., meta-aramid fabric.

[0070] (2) Para-aramid: Yantai Taihexing Materials Technology Co., Ltd., para-aramid woven fabric, product number TH5301.

[0071] (3) Diphenylmethane diisocyanate: Shanghai Aladdin Biochemical Technology Co., Ltd., item number M106783.

[0072] (4) Polymethylene polyphenyl polyisocyanate: Shanghai Aladdin Biochemical Technology Co., Ltd., item number P304914.

[0073] (5) Toluene diisocyanate: Shanghai Aladdin Biochemical Technology Co., Ltd., item number T135411.

[0074] (6) Triphenylmethane triisocyanate (20% solution, solvent is chlorobenzene): Shanghai Aladdin Biochemical Technology Co., Ltd., item number M303165.

[0075] II. The material-related testing standards in the embodiments and comparative examples of this invention are as follows:

[0076] (1) Tensile strength: Refer to GB / T 34219-2017;

[0077] (2) Fire resistance characteristics: Burn at 1000℃ for 10 minutes and observe whether it burns through;

[0078] (3) Thermal insulation properties: its surface temperature was tested by burning at 1000℃;

[0079] (4) Thermal conductivity at 200℃, 400℃, 600℃, and 800℃: Refer to ASTM C-201;

[0080] (5) Thermal shrinkage: The residual expansion or shrinkage of its length after being kept at 200℃ for 1 hour and cooled to room temperature;

[0081] (6) Peel strength test: Refer to GB / T 2791-1995 to test the peel strength between the fireproof layer and the support layer.

[0082] Unless otherwise specified, all aspects of this invention can be referenced from existing technologies, such as the coating of isocyanate curing agents between different material layers, and the connection methods between the bag body and the handles and Velcro. Example 1

[0083] like Figure 1 As shown, the fireproof and explosion-proof mobile phone bag includes: a bag body 4 for holding the mobile phone; the right side opening of the fireproof and explosion-proof mobile phone bag is opened and closed by a first meta-aramid flame-retardant Velcro 5 and a second meta-aramid flame-retardant Velcro 6; a handle 7 made of meta-aramid fiber is added to the upper right corner of the fireproof and explosion-proof mobile phone bag; the bag body 4 of the fireproof and explosion-proof mobile phone bag is fixed to the handle 7 by meta-aramid flame-retardant yarn.

[0084] like Figure 2 As shown, the fireproof and explosion-proof bag material for bag body 4 has a three-layer structure, consisting of a fireproof layer 1, a heat insulation layer 2, and a support layer 3 from the inside out. These layers are respectively made of meta-aramid fiber (0.5 mm thick), silica-hydroxyl-functionalized polyimide aerogel (0.02 mm thick), and para-aramid fiber (5 mm thick). The fireproof and explosion-proof bag material is prepared using the following method:

[0085] Step 1: Coat the support layer 3 with a diphenylmethane diisocyanate curing agent solution (the curing agent accounts for 0.05% of the mass of the fireproof and explosion-proof bag material), and place the heat insulation layer 2 on the support layer 3 coated with the isocyanate curing agent; wherein, the diphenylmethane diisocyanate curing agent solution is an acetone solution of diphenylmethane diisocyanate curing agent with a mass concentration of 15%.

[0086] Step 2: Coat the heat insulation layer 2 with a diphenylmethane diisocyanate curing agent solution (the curing agent accounts for 0.05% of the mass of the fireproof and explosion-proof bag material), and place the fireproof layer 1 on top to prepare a fireproof layer 1-heat insulation layer 2-support layer 3 composite. The diphenylmethane diisocyanate curing agent solution is an acetone solution of diphenylmethane diisocyanate curing agent with a mass concentration of 15%.

[0087] Step 3: The fireproof layer 1-heat insulation layer 2-support layer 3 composite is vacuum dried at 40°C for 48 hours to obtain the fireproof and explosion-proof bag material.

[0088] In this embodiment, the preparation method of silica-hydroxyl-functionalized polyimide aerogel is as follows:

[0089] A mixture was prepared by mixing aromatic dianhydride, hydroxy-functionalized aromatic diamine and N-methylpyrrolidone solution, with the molar ratio of aromatic dianhydride to hydroxy-functionalized diamine controlled at 10:9.

[0090] An N-methylpyrrolidone solution of an aromatic triamine and silica aerogel powder are added to the mixture and mixed evenly. A dehydrating agent and a catalyst are added, and after mixing evenly, the mixture is processed into shape and allowed to stand to gel. The molar ratio of the aromatic triamine to the aromatic dianhydride is 0.5:10, and the molar ratio of the dehydrating agent to the aromatic dianhydride is 8:1. The molar amounts of the catalyst and the dehydrating agent are equal.

[0091] The gel was solvent-exchanged in N-methylpyrrolidone for 2 days, dried with supercritical carbon dioxide, and then vacuum dried at 80°C to obtain silica-hydroxyl-functionalized polyimide aerogel.

[0092] The aromatic dianhydride is 3,3',4,4'-biphenyltetracarboxylic acid dianhydride;

[0093] The hydroxyl-functionalized aromatic diamine is 3,3'-dihydroxybenzidine;

[0094] The aromatic triamine is 1,3,5-triaminophenoxybenzene;

[0095] The dehydrating agent is acetic anhydride;

[0096] The catalyst is pyridine;

[0097] In the silica-hydroxy functionalized polyimide aerogel, the mass percentage of silica aerogel powder is 40%, and the mass percentage of polyimide is 60%. Example 2

[0098] like Figure 1 As shown, the fireproof and explosion-proof mobile phone bag includes: a bag body 4 for holding the mobile phone; the right side opening of the fireproof and explosion-proof mobile phone bag is opened and closed by a first meta-aramid flame-retardant Velcro 5 and a second meta-aramid flame-retardant Velcro 6; a handle 7 made of meta-aramid fiber is added to the upper right corner of the fireproof and explosion-proof mobile phone bag; the bag body 4 of the fireproof and explosion-proof mobile phone bag is fixed to the handle 7 by meta-aramid flame-retardant yarn.

[0099] like Figure 2 As shown, the fireproof and explosion-proof bag material for bag body 4 has a three-layer structure, consisting of a fireproof layer 1, a heat insulation layer 2, and a support layer 3 from the inside out. The materials used are meta-aramid fiber (5mm thick), silica-hydroxyl functionalized polyimide aerogel (1mm thick), and para-aramid fiber (0.5mm thick), respectively. The fireproof and explosion-proof bag material is prepared using the following method:

[0100] Step 1: Coat the support layer 3 with a toluene diisocyanate curing agent solution (the curing agent accounts for 1% of the mass of the fireproof and explosion-proof bag material), and place the heat insulation layer 2 on the support layer 3 coated with the isocyanate curing agent; wherein, the toluene diisocyanate curing agent solution is a benzene solution of toluene diisocyanate curing agent with a mass concentration of 18%.

[0101] Step 2: Coat the heat insulation layer 2 with a toluene diisocyanate curing agent solution (the curing agent mass accounts for 0.5% of the mass of the fireproof and explosion-proof bag material), and place the fireproof layer 1 on top to prepare a fireproof layer 1-heat insulation layer 2-support layer 3 composite. The toluene diisocyanate curing agent solution is a benzene solution of toluene diisocyanate curing agent with a mass concentration of 18%.

[0102] Step 3: The fireproof layer 1-heat insulation layer 2-support layer 3 composite is vacuum dried at 60°C for 24 hours to obtain the fireproof and explosion-proof bag material.

[0103] In this embodiment, the preparation method of silica-hydroxyl-functionalized polyimide aerogel is as follows:

[0104] A mixture was prepared by mixing aromatic dianhydride, hydroxyl-functionalized aromatic diamine, and N-methylpyrrolidone solution, with the molar ratio of aromatic dianhydride to hydroxyl-functionalized diamine controlled at 10:9.5.

[0105] An N-methylpyrrolidone solution of an aromatic triamine and silica aerogel powder are added to the mixture and mixed evenly. A dehydrating agent and a catalyst are added, and after mixing evenly, the mixture is processed into shape and allowed to stand to gel. The molar ratio of the aromatic triamine to the aromatic dianhydride is 0.35:10, and the molar ratio of the dehydrating agent to the aromatic dianhydride is 7:1. The molar amounts of the catalyst and the dehydrating agent are equal.

[0106] The gel was solvent-exchanged in acetone solution for 5 days, dried with supercritical carbon dioxide, and then vacuum dried at 40°C to obtain silica-hydroxy functionalized polyimide aerogel.

[0107] The aromatic dianhydride is pyromellitic dianhydride;

[0108] The hydroxyl-functionalized aromatic diamine is 3,3'-dihydroxybenzidine;

[0109] The aromatic triamine is 1,3,5-triaminobenzene;

[0110] The dehydrating agent is propionic anhydride;

[0111] The catalyst is isoquinoline;

[0112] In the silica-hydroxy functionalized polyimide aerogel, the mass percentage of silica aerogel powder is 25%, and the mass percentage of polyimide is 75%. Example 3

[0113] like Figure 1 As shown, the fireproof and explosion-proof mobile phone bag includes: a bag body 4 for holding the mobile phone; the right side opening of the fireproof and explosion-proof mobile phone bag is opened and closed by a first meta-aramid flame-retardant Velcro 5 and a second meta-aramid flame-retardant Velcro 6; a handle 7 made of meta-aramid fiber is added to the upper right corner of the fireproof and explosion-proof mobile phone bag; the bag body 4 of the fireproof and explosion-proof mobile phone bag is fixed to the handle 7 by meta-aramid flame-retardant yarn.

[0114] like Figure 2 As shown, the fireproof and explosion-proof bag material for bag body 4 has a three-layer structure, consisting of a fireproof layer 1, a heat insulation layer 2, and a support layer 3 from the inside out. The materials used are meta-aramid fiber (2mm thick), silica-hydroxyl functionalized polyimide aerogel (2mm thick), and para-aramid fiber (2mm thick), respectively. The fireproof and explosion-proof bag material is prepared using the following method:

[0115] Step 1: Coat the support layer 3 with a polymethylene polyphenyl polyisocyanate curing agent solution (the curing agent accounts for 0.5% of the mass of the fireproof and explosion-proof bag material), and place the heat insulation layer 2 on the support layer 3 coated with the isocyanate curing agent; wherein, the polymethylene polyphenyl polyisocyanate curing agent solution is a toluene solution of polymethylene polyphenyl polyisocyanate curing agent with a mass concentration of 20%.

[0116] Step 2: Coat the heat insulation layer 2 with a polymethylene polyphenyl polyisocyanate curing agent (the curing agent accounts for 1% of the mass of the fireproof and explosion-proof bag material), and place the fireproof layer 1 on top to prepare a fireproof layer 1-heat insulation layer 2-support layer 3 composite. The polymethylene polyphenyl polyisocyanate curing agent solution is a toluene solution of polymethylene polyphenyl polyisocyanate curing agent with a mass concentration of 20%.

[0117] Step 3: The fireproof layer 1-heat insulation layer 2-support layer 3 composite is vacuum dried at 100°C for 20 hours to obtain the fireproof and explosion-proof bag material.

[0118] In this embodiment, the preparation method of silica-hydroxyl-functionalized polyimide aerogel is as follows:

[0119] A mixture was prepared by mixing aromatic dianhydride, hydroxy-functionalized aromatic diamine and N-methylpyrrolidone solution, with the molar ratio of aromatic dianhydride to hydroxy-functionalized diamine controlled at 10:9.

[0120] An N-methylpyrrolidone solution of an aromatic triamine and silica aerogel powder are added to the mixture and mixed evenly. A dehydrating agent and a catalyst are added, and after mixing evenly, the mixture is processed into shape and allowed to stand to gel. The molar ratio of the aromatic triamine to the aromatic dianhydride is 0.7:10, and the molar ratio of the dehydrating agent to the aromatic dianhydride is 8:1.

[0121] The gel was solvent-exchanged in an N-methylpyrrolidone solution for 1 day, dried using supercritical carbon dioxide, and then vacuum dried at 80°C to obtain silica-hydroxy functionalized polyimide aerogel.

[0122] Furthermore, the aromatic dianhydride is 3,3',4,4'-benzophenone tetracarboxylic dianhydride;

[0123] The hydroxyl-functionalized aromatic diamine is 3,3'-dihydroxybenzidine;

[0124] The aromatic triamine is 1,3,5-triaminophenoxybenzene;

[0125] The dehydrating agent is propionic anhydride;

[0126] The catalyst is β-methylpyridine;

[0127] In the silica-hydroxyfunctionalized polyimide aerogel, the silica aerogel powder accounts for 10% by mass and the polyimide accounts for 90% by mass. Example 4

[0128] like Figure 1 As shown, the fireproof and explosion-proof mobile phone bag includes: a bag body 4 for holding the mobile phone; the right side opening of the fireproof and explosion-proof mobile phone bag is opened and closed by a first meta-aramid flame-retardant Velcro 5 and a second meta-aramid flame-retardant Velcro 6; a handle 7 made of meta-aramid fiber is added to the upper right corner of the fireproof and explosion-proof mobile phone bag; the bag body 4 of the fireproof and explosion-proof mobile phone bag is fixed to the handle 7 by meta-aramid flame-retardant yarn.

[0129] like Figure 2 As shown, the fireproof and explosion-proof bag material for bag body 4 has a three-layer structure, consisting of a fireproof layer 1, a heat insulation layer 2, and a support layer 3 from the inside out. The materials used are meta-aramid fiber (2mm thick), silica-hydroxyl functionalized polyimide aerogel (2mm thick), and para-aramid fiber (2mm thick), respectively. The fireproof and explosion-proof bag material is prepared using the following method:

[0130] Step 1: Coat the support layer 3 with a triphenylmethane triisocyanate curing agent solution (the curing agent accounts for 3% of the mass of the fireproof and explosion-proof bag material), and place the heat insulation layer 2 on the support layer 3 coated with the isocyanate curing agent; wherein, the triphenylmethane triisocyanate curing agent solution is a chlorobenzene solution of triphenylmethane triisocyanate curing agent with a mass concentration of 20%.

[0131] Step 2: Coat the heat insulation layer 2 with a triphenylmethane triisocyanate curing agent (the curing agent accounts for 2% of the mass of the fireproof and explosion-proof bag material), and place the fireproof layer 1 on top to prepare a fireproof layer 1-heat insulation layer 2-support layer 3 composite. The triphenylmethane triisocyanate curing agent solution is a chlorobenzene solution of triphenylmethane triisocyanate curing agent with a mass concentration of 20%.

[0132] Step 3: The fireproof layer 1-heat insulation layer 2-support layer 3 composite is vacuum dried at 120°C for 12 hours to obtain the fireproof and explosion-proof bag material.

[0133] In this embodiment, the preparation method of silica-hydroxyl-functionalized polyimide aerogel is as follows:

[0134] A mixture was prepared by mixing aromatic dianhydride, hydroxy-functionalized aromatic diamine and N-methylpyrrolidone solution, with the molar ratio of aromatic dianhydride to hydroxy-functionalized diamine controlled at 10:9.5.

[0135] An N-methylpyrrolidone solution of an aromatic triamine and silica aerogel powder are added to the mixture and mixed evenly. A dehydrating agent and a catalyst are added, and after mixing evenly, the mixture is processed into shape and allowed to stand to gel. The molar ratio of the aromatic triamine to the aromatic dianhydride is 0.6:10, and the molar ratio of the dehydrating agent to the aromatic dianhydride is 8:1.

[0136] The gel was solvent-exchanged in an N-methylpyrrolidone solution for 1 day, dried using supercritical carbon dioxide, and then vacuum dried at 80°C to obtain silica-hydroxy functionalized polyimide aerogel.

[0137] Furthermore, the aromatic dianhydride is 3,3',4,4'-benzophenone tetracarboxylic dianhydride;

[0138] The hydroxyl-functionalized aromatic diamine is 3,3'-dihydroxybenzidine;

[0139] The aromatic triamine is 1,3,5-triaminophenoxybenzene;

[0140] The dehydrating agent is propionic anhydride;

[0141] The catalyst is β-methylpyridine;

[0142] In the silica-hydroxyfunctionalized polyimide aerogel, the silica aerogel powder accounts for 10% by mass and the polyimide accounts for 90% by mass. Example 5

[0143] like Figure 1 As shown, the fireproof and explosion-proof mobile phone bag includes: a bag body 4 for holding the mobile phone; the right side opening of the fireproof and explosion-proof mobile phone bag is opened and closed by a first meta-aramid flame-retardant Velcro 5 and a second meta-aramid flame-retardant Velcro 6; a handle 7 made of meta-aramid fiber is added to the upper right corner of the fireproof and explosion-proof mobile phone bag; the bag body 4 of the fireproof and explosion-proof mobile phone bag is fixed to the handle 7 by meta-aramid flame-retardant yarn.

[0144] like Figure 2 As shown, the fireproof and explosion-proof bag material for bag body 4 has a three-layer structure, consisting of a fireproof layer 1, a heat insulation layer 2, and a support layer 3 from the inside out. The materials used are meta-aramid fiber (2mm thick), silica-hydroxyl functionalized polyimide aerogel (2mm thick), and para-aramid fiber (2mm thick), respectively. The fireproof and explosion-proof bag material is prepared using the following method:

[0145] Step 1: Coat the support layer 3 with a polymethylene polyphenyl polyisocyanate curing agent solution (the curing agent accounts for 0.5% of the mass of the fireproof and explosion-proof bag material), and place the heat insulation layer 2 on the support layer 3 coated with the isocyanate curing agent; wherein, the polymethylene polyphenyl polyisocyanate curing agent solution is a toluene solution of polymethylene polyphenyl polyisocyanate curing agent with a mass concentration of 30%.

[0146] Step 2: Coat the heat insulation layer 2 with a polymethylene polyphenyl polyisocyanate curing agent (the curing agent accounts for 1% of the mass of the fireproof and explosion-proof bag material), and place the fireproof layer 1 on top to prepare a fireproof layer 1-heat insulation layer 2-support layer 3 composite. The polymethylene polyphenyl polyisocyanate curing agent solution is a toluene solution of polymethylene polyphenyl polyisocyanate curing agent with a mass concentration of 30%.

[0147] Step 3: The fireproof layer 1-heat insulation layer 2-support layer 3 composite is vacuum dried at 100°C for 20 hours to obtain the fireproof and explosion-proof bag material.

[0148] In this embodiment, the preparation method of silica-hydroxy functionalized polyimide aerogel is the same as that in Example 3. Example 6

[0149] like Figure 1 As shown, the fireproof and explosion-proof mobile phone bag includes: a bag body 4 for holding the mobile phone; the right side opening of the fireproof and explosion-proof mobile phone bag is opened and closed by a first meta-aramid flame-retardant Velcro 5 and a second meta-aramid flame-retardant Velcro 6; a handle 7 made of meta-aramid fiber is added to the upper right corner of the fireproof and explosion-proof mobile phone bag; the bag body 4 of the fireproof and explosion-proof mobile phone bag is fixed to the handle 7 by meta-aramid flame-retardant yarn.

[0150] like Figure 2 As shown, the fireproof and explosion-proof bag material for bag body 4 has a three-layer structure, consisting of a fireproof layer 1, a heat insulation layer 2, and a support layer 3 from the inside out. These layers are respectively made of meta-aramid fiber (0.5 mm thick), silica-hydroxyl-functionalized polyimide aerogel (0.02 mm thick), and para-aramid fiber (5 mm thick). The fireproof and explosion-proof bag material is prepared using the following method:

[0151] Step 1: Coat the support layer 3 with a diphenylmethane diisocyanate curing agent solution (the curing agent accounts for 0.05% of the mass of the fireproof and explosion-proof bag material), and place the heat insulation layer 2 on the support layer 3 coated with the isocyanate curing agent; wherein, the diphenylmethane diisocyanate curing agent solution is an acetone solution of diphenylmethane diisocyanate curing agent with a mass concentration of 15%.

[0152] Step 2: Coat the heat insulation layer 2 with a diphenylmethane diisocyanate curing agent solution (the curing agent accounts for 0.05% of the mass of the fireproof and explosion-proof bag material), and place the fireproof layer 1 on top to prepare a fireproof layer 1-heat insulation layer 2-support layer 3 composite. The diphenylmethane diisocyanate curing agent solution is an acetone solution of diphenylmethane diisocyanate curing agent with a mass concentration of 15%.

[0153] Step 3: The fireproof layer 1-heat insulation layer 2-support layer 3 composite is vacuum dried at 80°C for 24 hours to obtain the fireproof and explosion-proof bag material.

[0154] In this embodiment, the preparation method of silica-hydroxy functionalized polyimide aerogel is the same as that in Example 1.

[0155] Comparative Example 1

[0156] Fireproof and explosion-proof bag materials were prepared using the same method as in Example 1, except that there was no heat insulation layer 2 in Comparative Example 1. The specific preparation process is as follows:

[0157] The fireproof and explosion-proof mobile phone bag includes: a bag body 4 for holding the mobile phone; an opening on the right side of the fireproof and explosion-proof mobile phone bag, which is opened and closed by a first meta-aramid flame-retardant Velcro 5 and a second meta-aramid flame-retardant Velcro 6; a handle 7 made of meta-aramid fiber added to the upper right corner of the fireproof and explosion-proof mobile phone bag; and the bag body 4 of the fireproof and explosion-proof mobile phone bag is fixed to the handle 7 by meta-aramid flame-retardant yarn.

[0158] The fireproof and explosion-proof bag material for bag body 4 has a two-layer structure, consisting of a fireproof layer 1 and a support layer 3 from the inside out. The fireproof and explosion-proof bag material is made of meta-aramid fiber (0.5 mm thick) and para-aramid fiber (5 mm thick), respectively. The fireproof and explosion-proof bag material is prepared using the following method:

[0159] Step 1: Coat the support layer 3 with a layer of diphenylmethane diisocyanate curing agent solution (the curing agent mass accounts for 0.1% of the mass of the fireproof and explosion-proof bag material), and place the fireproof layer 1 on it to prepare the fireproof layer 1-support layer 3 composite; wherein, the diphenylmethane diisocyanate curing agent solution is an acetone solution of diphenylmethane diisocyanate curing agent with a mass concentration of 15%.

[0160] Step 2: The fireproof layer 1-support layer 3 composite is vacuum dried at 40°C for 48 hours to obtain the flexible aramid aerogel fireproof and explosion-proof bag.

[0161] Comparative Example 2

[0162] Fireproof and explosion-proof bag materials were prepared using the same method as in Example 1, except that the materials of fireproof layer 1 and support layer 3 were changed in Comparative Example 2. The specific preparation process is as follows:

[0163] The fireproof and explosion-proof mobile phone bag includes: a bag body 4 for holding the mobile phone; an opening on the right side of the fireproof and explosion-proof mobile phone bag, which can be opened and closed through a first meta-aramid flame-retardant Velcro 5 and a second meta-aramid flame-retardant Velcro 6; a handle 7 made of meta-aramid fiber added to the upper right corner of the fireproof and explosion-proof mobile phone bag; and the bag body 4 of the fireproof and explosion-proof mobile phone bag is fixed to the handle 7 by meta-aramid flame-retardant yarn.

[0164] The fireproof and explosion-proof bag material for bag body 4 has a three-layer structure, consisting of a fireproof layer 1, a heat insulation layer 2, and a support layer 3 from the inside out. These layers are respectively made of acrylic fiber (0.5 mm thick), silica-hydroxyl-functionalized polyimide aerogel (0.02 mm thick), and acrylic fiber (5 mm thick). The fireproof and explosion-proof bag material is prepared using the following method:

[0165] Step 1: Coat the support layer 3 with a diphenylmethane diisocyanate curing agent solution (the curing agent accounts for 0.05% of the mass of the fireproof and explosion-proof bag material), and place the heat insulation layer 2 on the support layer 3 coated with the isocyanate curing agent; wherein, the diphenylmethane diisocyanate curing agent solution is an acetone solution of diphenylmethane diisocyanate curing agent with a mass concentration of 15%.

[0166] Step 2: Coat the heat insulation layer 2 with a diphenylmethane diisocyanate curing agent solution (the curing agent accounts for 0.05% of the mass of the fireproof and explosion-proof bag material), and place the fireproof layer 1 on top to prepare a fireproof layer 1-heat insulation layer 2-support layer 3 composite. The diphenylmethane diisocyanate curing agent solution is an acetone solution of diphenylmethane diisocyanate curing agent with a mass concentration of 15%.

[0167] Step 3: The fireproof layer 1-heat insulation layer 2-support layer 3 composite is vacuum dried at 40°C for 48 hours to obtain the fireproof and explosion-proof bag material.

[0168] Comparative Example 3

[0169] Fireproof and explosion-proof bag materials were prepared using the same method as in Example 1, except that the isocyanate curing agent was replaced with a PVDF binder in Comparative Example 3. The specific preparation process is as follows:

[0170] The fireproof and explosion-proof mobile phone bag includes: a bag body 4 for holding the mobile phone; an opening on the right side of the fireproof and explosion-proof mobile phone bag, which can be opened and closed through a first meta-aramid flame-retardant Velcro 5 and a second meta-aramid flame-retardant Velcro 6; a handle 7 made of meta-aramid fiber added to the upper right corner of the fireproof and explosion-proof mobile phone bag; and the bag body 4 of the fireproof and explosion-proof mobile phone bag is fixed to the handle 7 by meta-aramid flame-retardant yarn.

[0171] The fireproof and explosion-proof bag material for bag body 4 has a three-layer structure, consisting of a fireproof layer 1, a heat insulation layer 2, and a support layer 3 from the inside out. These layers are respectively made of meta-aramid fiber (0.5 mm thick), silica-hydroxyl-functionalized polyimide aerogel (0.02 mm thick), and para-aramid fiber (5 mm thick). The fireproof and explosion-proof bag material is prepared using the following method:

[0172] Step 1: Coat the support layer 3 with a PVDF adhesive solution (the mass of the PVDF adhesive accounts for 0.05% of the mass of the fireproof and explosion-proof bag material), and place the heat insulation layer 2 on the support layer 3 coated with isocyanate curing agent; wherein, the PVDF adhesive solution is an NMP solution of PVDF adhesive with a mass concentration of 20%.

[0173] Step 2: Coat the insulation layer 2 with a PVDF adhesive solution (PVDF adhesive accounts for 0.05% of the mass of the fireproof and explosion-proof bag material), and place the fireproof layer 1 on top to prepare a fireproof layer 1-insulation layer 2-support layer 3 composite. The PVDF adhesive solution is an NMP solution of PVDF adhesive with a mass concentration of 20%.

[0174] Step 3: The fireproof layer 1-heat insulation layer 2-support layer 3 composite is vacuum dried at 40°C for 48 hours to obtain the fireproof and explosion-proof bag material.

[0175] Comparative Example 4

[0176] Fireproof and explosion-proof bag materials were prepared using the same method as in Example 3, except that the mass concentration of the isocyanate curing agent solution was reduced in Comparative Example 4 to 10% (lower than the mass concentration specified in this invention). The specific preparation process is as follows:

[0177] The fireproof and explosion-proof mobile phone bag includes: a bag body 4 for holding the mobile phone; an opening on the right side of the fireproof and explosion-proof mobile phone bag, which can be opened and closed through a first meta-aramid flame-retardant Velcro 5 and a second meta-aramid flame-retardant Velcro 6; a handle 7 made of meta-aramid fiber added to the upper right corner of the fireproof and explosion-proof mobile phone bag; and the bag body 4 of the fireproof and explosion-proof mobile phone bag is fixed to the handle 7 by meta-aramid flame-retardant yarn.

[0178] The fireproof and explosion-proof bag material for bag body 4 has a three-layer structure, consisting of a fireproof layer 1, a heat insulation layer 2, and a support layer 3 from the inside out. These layers are respectively made of meta-aramid fiber (2mm thick), silica-hydroxyl-functionalized polyimide aerogel (2mm thick), and para-aramid fiber (2mm thick). The fireproof and explosion-proof bag material is prepared using the following method:

[0179] Step 1: Coat the support layer 3 with a polymethylene polyphenyl polyisocyanate curing agent solution (the curing agent accounts for 0.5% of the mass of the fireproof and explosion-proof bag material), and place the heat insulation layer 2 on the support layer 3 coated with the isocyanate curing agent; wherein, the polymethylene polyphenyl polyisocyanate curing agent solution is a toluene solution of polymethylene polyphenyl polyisocyanate curing agent with a mass concentration of 10%.

[0180] Step 2: Coat the heat insulation layer 2 with a polymethylene polyphenyl polyisocyanate curing agent (the curing agent accounts for 1% of the mass of the fireproof and explosion-proof bag material), and place the fireproof layer 1 on top to prepare a fireproof layer 1-heat insulation layer 2-support layer 3 composite. The polymethylene polyphenyl polyisocyanate curing agent solution is a toluene solution of polymethylene polyphenyl polyisocyanate curing agent with a mass concentration of 10%.

[0181] Step 3: The fireproof layer 1-heat insulation layer 2-support layer 3 composite is vacuum dried at 100°C for 20 hours to obtain the fireproof and explosion-proof bag material.

[0182] Comparative Example 5

[0183] Fireproof and explosion-proof bag materials were prepared using the same method as in Example 3, except that the mass concentration of the isocyanate curing agent solution was increased in Comparative Example 5 to 35% (higher than the mass concentration specified in this invention). The specific preparation process is as follows:

[0184] The fireproof and explosion-proof mobile phone bag includes: a bag body 4 for holding the mobile phone; an opening on the right side of the fireproof and explosion-proof mobile phone bag, which can be opened and closed through a first meta-aramid flame-retardant Velcro 5 and a second meta-aramid flame-retardant Velcro 6; a handle 7 made of meta-aramid fiber added to the upper right corner of the fireproof and explosion-proof mobile phone bag; and the bag body 4 of the fireproof and explosion-proof mobile phone bag is fixed to the handle 7 by meta-aramid flame-retardant yarn.

[0185] The fireproof and explosion-proof bag material for bag body 4 has a three-layer structure, consisting of a fireproof layer 1, a heat insulation layer 2, and a support layer 3 from the inside out. These layers are respectively made of meta-aramid fiber (2mm thick), silica-hydroxyl-functionalized polyimide aerogel (2mm thick), and para-aramid fiber (2mm thick). The fireproof and explosion-proof bag material is prepared using the following method:

[0186] Step 1: Coat the support layer 3 with a polymethylene polyphenyl polyisocyanate curing agent solution (the curing agent accounts for 0.5% of the mass of the fireproof and explosion-proof bag material), and place the heat insulation layer 2 on the support layer 3 coated with the isocyanate curing agent; wherein, the polymethylene polyphenyl polyisocyanate curing agent solution is a toluene solution of polymethylene polyphenyl polyisocyanate curing agent with a mass concentration of 35%.

[0187] Step 2: Coat the heat insulation layer 2 with a polymethylene polyphenyl polyisocyanate curing agent (the curing agent accounts for 1% of the mass of the fireproof and explosion-proof bag material), and place the fireproof layer 1 on top to prepare a fireproof layer 1-heat insulation layer 2-support layer 3 composite. The polymethylene polyphenyl polyisocyanate curing agent solution is a toluene solution of polymethylene polyphenyl polyisocyanate curing agent with a mass concentration of 35%.

[0188] Step 3: The fireproof layer 1-heat insulation layer 2-support layer 3 composite is vacuum dried at 100°C for 20 hours to obtain the fireproof and explosion-proof bag material.

[0189] The tensile strength, fire resistance, heat insulation, thermal conductivity, and peel strength of the mobile phone explosion-proof bags of the examples and comparative examples were tested respectively, and the specific results are shown in Table 1.

[0190] Comparative Example 6

[0191] Fireproof and explosion-proof bag materials were prepared using the same method as in Example 1, except that the material of the heat insulation layer 2 was changed in Comparative Example 6. The specific preparation process is as follows:

[0192] The fireproof and explosion-proof mobile phone bag includes: a bag body 4 for holding the mobile phone; an opening on the right side of the fireproof and explosion-proof mobile phone bag, which can be opened and closed through a first meta-aramid flame-retardant Velcro 5 and a second meta-aramid flame-retardant Velcro 6; a handle 7 made of meta-aramid fiber added to the upper right corner of the fireproof and explosion-proof mobile phone bag; and the bag body 4 of the fireproof and explosion-proof mobile phone bag is fixed to the handle 7 by meta-aramid flame-retardant yarn.

[0193] The fireproof and explosion-proof bag material for bag body 4 has a three-layer structure, consisting of a fireproof layer 1, a heat insulation layer 2, and a support layer 3 from the inside out. These layers are respectively made of meta-aramid fiber (0.5 mm thick), polyimide aerogel (0.02 mm thick), and para-aramid fiber (5 mm thick). The fireproof and explosion-proof bag material is prepared using the following method:

[0194] Step 1: Coat the support layer 3 with a diphenylmethane diisocyanate curing agent solution (the curing agent accounts for 0.05% of the mass of the fireproof and explosion-proof bag material), and place the heat insulation layer 2 on the support layer 3 coated with the isocyanate curing agent; wherein, the diphenylmethane diisocyanate curing agent solution is an acetone solution of diphenylmethane diisocyanate curing agent with a mass concentration of 15%.

[0195] Step 2: Coat the heat insulation layer 2 with a diphenylmethane diisocyanate curing agent solution (the curing agent accounts for 0.05% of the mass of the fireproof and explosion-proof bag material), and place the fireproof layer 1 on top to prepare a fireproof layer 1-heat insulation layer 2-support layer 3 composite. The diphenylmethane diisocyanate curing agent solution is an acetone solution of diphenylmethane diisocyanate curing agent with a mass concentration of 15%.

[0196] Step 3: The fireproof layer 1-heat insulation layer 2-support layer 3 composite is vacuum dried at 40°C for 48 hours to obtain the fireproof and explosion-proof bag material.

[0197] Comparative Example 7

[0198] Fireproof and explosion-proof bag materials were prepared using the same method as in Example 1, except that no aromatic triamine was added when preparing the silica-hydroxyl-functionalized polyimide aerogel in Comparative Example 7. The specific preparation process is as follows:

[0199] A mixture was prepared by mixing aromatic dianhydride, hydroxy-functionalized aromatic diamine and N-methylpyrrolidone solution, with the molar ratio of aromatic dianhydride to hydroxy-functionalized diamine controlled at 10:9.

[0200] Silica aerogel powder is added to the mixture and mixed evenly. A dehydrating agent and a catalyst are added and mixed evenly. The mixture is then processed into shape and allowed to stand to gel. The molar ratio of the dehydrating agent to the aromatic dianhydride is 8:1. The molar amounts of the catalyst and the dehydrating agent are equal.

[0201] The gel was solvent-exchanged in N-methylpyrrolidone for 2 days, dried with supercritical carbon dioxide, and then vacuum dried at 80°C to obtain silica-hydroxyl-functionalized polyimide aerogel.

[0202] The aromatic dianhydride is 3,3',4,4'-biphenyltetracarboxylic acid dianhydride;

[0203] The hydroxyl-functionalized aromatic diamine is 3,3'-dihydroxybenzidine;

[0204] The dehydrating agent is acetic anhydride;

[0205] The catalyst is pyridine;

[0206] In the silica-hydroxy functionalized polyimide aerogel, the mass percentage of silica aerogel powder is 40%, and the mass percentage of polyimide is 60%.

[0207] Comparative Example 8

[0208] Fireproof and explosion-proof bag materials were prepared using the same method as in Example 1, except that: in the preparation of the heat insulation layer material in Comparative Example 8, silica aerogel powder was not added, which is equivalent to preparing hydroxyl-functionalized polyimide aerogel. The specific preparation process is as follows:

[0209] A mixture was prepared by mixing aromatic dianhydride, hydroxy-functionalized aromatic diamine and N-methylpyrrolidone solution, with the molar ratio of aromatic dianhydride to hydroxy-functionalized diamine controlled at 10:9.

[0210] An N-methylpyrrolidone solution of an aromatic triamine is added to the mixture and mixed thoroughly. A dehydrating agent and a catalyst are then added and mixed thoroughly. The mixture is then processed into shape and allowed to stand to gel. The molar ratio of the aromatic triamine to the aromatic dianhydride is 0.5:10, and the molar ratio of the dehydrating agent to the aromatic dianhydride is 8:1. The molar amounts of the catalyst and the dehydrating agent are equal.

[0211] The gel was solvent-exchanged in N-methylpyrrolidone for 2 days, dried with supercritical carbon dioxide, and then vacuum dried at 80°C to obtain hydroxyl-functionalized polyimide aerogel.

[0212] The aromatic dianhydride is 3,3',4,4'-biphenyltetracarboxylic acid dianhydride;

[0213] The hydroxyl-functionalized aromatic diamine is 3,3'-dihydroxybenzidine;

[0214] The aromatic triamine is 1,3,5-triaminophenoxybenzene;

[0215] The dehydrating agent is acetic anhydride;

[0216] The catalyst is pyridine.

[0217] Comparative Example 9

[0218] Fireproof and explosion-proof bag materials were prepared using the same method as in Example 1, except that in Comparative Example 9, when preparing the heat insulation layer material, 3,3'-dihydroxybenzidine was replaced with 3,3'-dimethoxybenzidine, which is equivalent to preparing a silica-polyimide aerogel. The specific preparation process is as follows:

[0219] A mixture was prepared by mixing aromatic dianhydride, diamine and N-methylpyrrolidone solution, and the molar ratio of aromatic dianhydride to hydroxyfunctionalized diamine was controlled to be 10:9.

[0220] An N-methylpyrrolidone solution of an aromatic triamine and silica aerogel powder are added to the mixture and mixed evenly. A dehydrating agent and a catalyst are added, and after mixing evenly, the mixture is processed into shape and allowed to stand to gel. The molar ratio of the aromatic triamine to the aromatic dianhydride is 0.5:10, and the molar ratio of the dehydrating agent to the aromatic dianhydride is 8:1. The molar amounts of the catalyst and the dehydrating agent are equal.

[0221] The gel was solvent-exchanged in N-methylpyrrolidone for 2 days, dried with supercritical carbon dioxide, and then vacuum dried at 80°C to obtain silica-polyimide aerogel.

[0222] The aromatic dianhydride is 3,3',4,4'-biphenyltetracarboxylic acid dianhydride;

[0223] The diamine is 3,3'-dihydroxybenzidine;

[0224] The aromatic triamine is 1,3,5-triaminophenoxybenzene;

[0225] The dehydrating agent is acetic anhydride;

[0226] The catalyst is pyridine;

[0227] In the silica-polyimide aerogel, the silica aerogel powder accounts for 40% by mass and the polyimide accounts for 60% by mass.

[0228] Table 1 Test data of the examples and comparative examples

[0229]

[0230] The data in the table above shows that the fireproof and explosion-proof bag materials prepared by the method described in this invention in Examples 1-6 can effectively reduce the thermal conductivity of the bag body and improve its fire resistance, heat insulation performance, and interlayer bonding strength when used in fireproof and explosion-proof bags. Furthermore, a comparison of the data from Examples 3 and 5 shows that the relationship between the thickness of the insulation layer and the concentration of the isocyanate curing agent solution is... c = c 0 ±1 and c 0 =2.5 h At +15, the resulting bag exhibits superior fire resistance, heat insulation, and strength properties. A comparison of the data from Examples 1 and 6 shows that when the mass percentage of isocyanate curing agent in the total mass of the fireproof and explosion-proof bag material is ≥0.1% and <1.5%, a heating temperature of ≥40℃ and <60℃ is more conducive to obtaining a product with excellent fire resistance, heat insulation, and mechanical properties.

[0231] The data comparison between Comparative Example 1 and Example 1 shows that if the aerogel insulation layer 2 is not added to the fireproof and explosion-proof bag, the heat insulation performance of the fireproof and explosion-proof bag will be significantly reduced. Therefore, the layer structure of the fireproof and explosion-proof bag material described in this invention is more conducive to obtaining fireproof and explosion-proof bags with excellent fire resistance and heat insulation performance.

[0232] A comparison of the data from Comparative Example 2 and Example 1 shows that if the materials of the fireproof layer 1 and the support layer 3 are replaced with acrylic fibers, the interlayer peel strength and fire resistance and heat insulation performance of the fireproof and explosion-proof bag will decrease significantly. Therefore, the synergy between the fireproof layer 1, the heat insulation layer 2, the support layer 3 and the diisocyanate curing agent in the preparation method described in this invention is more conducive to obtaining a fireproof and explosion-proof bag with excellent performance.

[0233] A comparison of the data from Comparative Example 3 and Example 1 shows that if the diisocyanate curing agent is replaced with PVDF adhesive, the interlayer peel strength, fire resistance, heat insulation, and strength performance of the fireproof and explosion-proof bag will all decrease significantly. In this invention, the fireproof layer, heat insulation layer, and support layer of the bag body are coated with an isocyanate curing agent. After vacuum heat treatment, the isocyanate forms chemical bonds with the terminal carboxyl / terminal amino groups of aramid and the terminal amino and hydroxyl groups of polyimide, which improves the bonding force between the fireproof layer, heat insulation layer, and support layer, further improving the mechanical strength of the bag body. Moreover, it can maximize the heat insulation performance of silica-hydroxy functionalized polyimide aerogel and maximize the flame retardant and strength performance of para-aramid and meta-aramid.

[0234] A comparison of the data from Comparative Example 4 and Example 3 shows that if the concentration of the diisocyanate curing agent solution is too low, the interlayer peel strength of the fireproof and explosion-proof bag will decrease significantly. This is because if the concentration of the diisocyanate curing agent solution is too low, more diisocyanate curing agent solution will penetrate into the fireproof layer, heat insulation layer, and support layer during the coating process, thus affecting the interlayer adhesion. In addition, since the diisocyanate curing agent has penetrated into the fireproof layer, heat insulation layer, and support layer, the contribution of para-aramid, silica-hydroxy functionalized polyimide aerogel, and meta-aramid to provide flame retardancy and heat insulation will also decrease, ultimately affecting the overall performance of the fireproof and explosion-proof bag.

[0235] A comparison of the data from Comparative Example 5 and Example 3 shows that if the concentration of the diisocyanate curing agent solution is too high, the heat insulation performance of the fireproof and explosion-proof bag will significantly decrease. This is because a high concentration of diisocyanate curing agent will clog the pores within the silica-hydroxyl-functionalized polyimide aerogel, ultimately leading to a decrease in the flame-retardant and heat-insulating performance of the fireproof and explosion-proof bag. Therefore, using the diisocyanate curing agent solution concentration specified in this invention is more conducive to obtaining fireproof and explosion-proof bag products with excellent fire resistance, heat insulation, and interlayer bonding strength.

[0236] The data comparison between Comparative Example 6 and Example 1 shows that if the silica-hydroxyfunctionalized polyimide aerogel is replaced with polyimide aerogel, the interlayer peel strength of the fireproof and explosion-proof bag will decrease significantly, the thermal shrinkage will increase significantly, and the high specific area structure cannot be effectively maintained at high temperatures, thus affecting the fireproof and explosion-proof performance of the fireproof and explosion-proof bag.

[0237] The comparison of data from Comparative Example 7 and Example 1 shows that if no aromatic triamine is added during the preparation of silica-hydroxy functionalized polyimide aerogel, the heat insulation performance and peel strength of the fireproof and explosion-proof bag will decrease significantly, the high specific surface area will disappear, heat cannot be effectively absorbed, and the contact sites between the curing agent and the heat insulation layer will be drastically reduced, thereby affecting the heat insulation performance and mechanical stability of the fireproof and explosion-proof bag.

[0238] A comparison of the data from Comparative Example 8 and Example 1 shows that if the silica-hydroxy-functionalized polyimide aerogel is replaced with hydroxy-functionalized polyimide aerogel, the thermal shrinkage of the fireproof and explosion-proof bag increases significantly, and the high specific area structure cannot be effectively maintained at high temperatures, thus affecting the fireproof and explosion-proof performance of the fireproof and explosion-proof bag.

[0239] The data comparison between Comparative Example 9 and Example 1 shows that if the silica-hydroxyfunctionalized polyimide aerogel is replaced with silica-polyimide aerogel, the reaction sites between the heat insulation layer and the curing agent are reduced, and the interlayer peel strength of the fireproof and explosion-proof bag is significantly reduced, thereby affecting the fireproof and explosion-proof performance of the fireproof and explosion-proof bag.

[0240] 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.

[0241] 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. An aramid aerogel fireproof and explosion-proof bag material for mobile phones, characterized in that, The fireproof and explosion-proof bag material includes, from the inside out, a fireproof layer, a heat insulation layer, and a support layer; The fireproof layer is selected from at least one of meta-aramid and para-aramid; the heat insulation layer is silica-hydroxyl-functionalized polyimide aerogel; the support layer is selected from at least one of meta-aramid and para-aramid. The fireproof and explosion-proof bag material is coated with an isocyanate curing agent solution between each layer. After the layers are composited, the fireproof and explosion-proof bag material is obtained by heating and drying. The preparation method of the silica-hydroxyl-functionalized polyimide aerogel includes the following steps: A mixture is prepared by mixing aromatic dianhydride, hydroxy-functionalized aromatic diamine and N-methylpyrrolidone solution, with the molar ratio of aromatic dianhydride to hydroxy-functionalized diamine controlled at 10:(9-9.5). An N-methylpyrrolidone solution of an aromatic triamine and silica aerogel powder are added to the mixture and mixed evenly. A dehydrating agent and a catalyst are added, and after mixing evenly, the mixture is processed into shape and allowed to stand to gel. The molar ratio of the aromatic triamine to the aromatic dianhydride is (0.35-0.7):10, and the molar ratio of the dehydrating agent to the aromatic dianhydride is (7-8):

1. The gel was solvent-exchanged in N-methylpyrrolidone and / or acetone solution for 1-5 days, dried with supercritical carbon dioxide, and then vacuum dried at 40-80℃ to obtain silica-hydroxyl-functionalized polyimide aerogel.

2. The aramid aerogel mobile phone fireproof and explosion-proof bag material according to claim 1, characterized in that, The aromatic dianhydride is selected from one or more of the following: 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, pyromellitic dianhydride, 3,3',4,4'-diphenylmethyl ether tetracarboxylic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-triphenyl diether tetracarboxylic dianhydride, and 4,4'-(hexafluoroisopropyl)bisphthalic acid dianhydride. The hydroxyl-functionalized aromatic diamine is 3,3'-dihydroxybenzidine; The aromatic triamine is selected from one or more of 1,3,5-triaminophenoxybenzene and 1,3,5-triaminobenzene; The dehydrating agent is acetic anhydride or propionic anhydride; The catalyst is selected from one or more of pyridine, isoquinoline and β-methylpyridine; The silica aerogel powder has a particle size of 1-20 μm and a density of 0.1-0.12 g / cm³. 3 ; In the silica-hydroxy functionalized polyimide aerogel, the mass percentage of silica aerogel powder is 10-40%, and the mass percentage of polyimide is 60-90%.

3. The aramid aerogel mobile phone fireproof and explosion-proof bag material according to claim 1, characterized in that, The isocyanate curing agent solution is a solution formed by dissolving an isocyanate curing agent in an organic solvent. The mass concentration of the isocyanate curing agent in the isocyanate curing agent solution is 15%-30%, and the functionality of the isocyanate groups in the isocyanate curing agent is not less than 2. The organic solvent is any one of benzene, toluene, chlorobenzene, nitrobenzene, and acetone.

4. The aramid aerogel mobile phone fireproof and explosion-proof bag material according to claim 1, characterized in that, The isocyanate curing agent is selected from at least one of diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, toluene diisocyanate, isophorone diisocyanate, and triphenylmethane triisocyanate.

5. The aramid aerogel mobile phone fireproof and explosion-proof bag material according to claim 1, characterized in that, The fireproof layer has a thickness of 0.5-5mm, the heat insulation layer has a thickness of 0.02-2mm, and the support layer has a thickness of 0.5-5mm.

6. The aramid aerogel mobile phone fireproof and explosion-proof bag material according to claim 1, characterized in that, The total mass of the fireproof and explosion-proof bag material is 100%, and the mass of the isocyanate curing agent is 0.1-5%.

7. The aramid aerogel mobile phone fireproof and explosion-proof bag material according to claim 1, characterized in that, The heating and drying process conditions are as follows: heating temperature is 40-120℃, and vacuum drying is performed for 12-48 hours.

8. A method for preparing an aramid aerogel fireproof and explosion-proof mobile phone bag material according to any one of claims 1-7, characterized in that, The preparation method is as follows: An isocyanate curing agent solution is coated onto the support layer, and the heat insulation layer is placed on the support layer coated with the isocyanate curing agent solution. Then, an isocyanate curing agent solution is coated on the heat insulation layer, and the fireproof layer is placed on the heat insulation layer to prepare a composite of fireproof layer-heat insulation layer-support layer; The composite of the fireproof layer-heat insulation layer-support layer is heated and dried to obtain the aramid aerogel mobile phone fireproof and explosion-proof bag material.

9. An application of an aramid aerogel mobile phone fireproof and explosion-proof bag material according to any one of claims 1-7, characterized in that, The aramid aerogel fireproof and explosion-proof bag material is used in fireproof and explosion-proof bags for mobile phones. The fireproof layer serves as the inner layer of the fireproof and explosion-proof bag, and the support layer serves as the outer layer of the fireproof and explosion-proof bag.

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