Flame-retardant heat-insulating film based on chopped glass fiber mat reinforcement and preparation method thereof

Abstract

The invention discloses a flame-retardant heat-insulating film based on chopped glass fiber mat reinforcement and a preparation method thereof, the flame-retardant heat-insulating film comprises a ceramizable flame-retardant heat-insulating material and a chopped glass fiber mat, the ceramizable flame-retardant heat-insulating material is immersed in the chopped glass fiber mat and covers the surface of the chopped glass fiber mat, and the flame-retardant heat-insulating film is prepared through vulcanization curing, the ceramic flame-retardant heat-insulating material is formed by mixing powder and base glue. The flame-retardant heat-insulating film reinforced based on the chopped glass fiber felt has the advantages of being easy to cut, high in strength, high in fire-resistant temperature and low in thickness. According to the preparation method, the chopped glass fiber mat and the ceramic flame-retardant heat-insulating material are subjected to multi-pass gluing and pressing, and the glass fibers are fully dispersed in the ceramic flame-retardant heat-insulating material, so that the material has good mechanical properties, meanwhile, the subsequent cutting difficulty is reduced, the overall working time is shortened, and the production efficiency is improved. The material mixing difficulty is reduced, the adding proportion of the powder can be increased, and the key performance such as flame retardance, fire resistance and heat insulation is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of fireproof and heat-insulating materials, and in particular relates to a flame-retardant heat-insulating film reinforced with chopped glass fiber mat and a preparation method thereof. Background Art

[0002] With the development of new energy electric vehicles, the safety of power batteries has become increasingly prominent. Fire incidents involving new energy vehicles have increased year-on-year, demonstrating that there is still significant room for improvement in thermal runaway protection materials for new energy vehicle power batteries. Currently, the power batteries used in new energy vehicles are primarily lithium batteries, and the current thermal runaway protection materials are primarily made of mica. Meanwhile, high-temperature resistant, ceramic-forming polymers are gaining popularity due to their superior performance. When exposed to high temperatures, ceramic-forming polymers undergo a ceramic-forming reaction, producing a glassy material with a ceramic-like structure that can withstand even higher temperatures and exhibit excellent thermal insulation properties. These high-temperature resistant, ceramic-forming polymers can also be used in other fields requiring thermal insulation, such as aerospace, shipbuilding, and aviation. However, during the ceramic-forming reaction, these high-temperature resistant, ceramic-forming polymers undergo a certain degree of systemic change, producing a certain amount of liquid phase. This means that during the initial ceramic-forming reaction, ceramic-forming materials typically experience a period of low mechanical strength, making them more susceptible to mechanical damage and failure. To overcome these issues, existing ceramic polymer insulation materials typically use fiber cloth, such as glass fiber cloth, as a reinforcing matrix to enhance overall mechanical strength. However, while fiber cloth enhances overall strength, it also makes subsequent shearing more difficult and complex, leading to high production costs and hindering large-scale production. Furthermore, the material requires a greater thickness to maintain flame-retardant and thermal-insulating properties. Currently, there are no reports of ceramic polymer insulation materials that can guarantee stable mechanical properties during the initial ceramicization reaction, facilitate processing, and achieve both flame-retardant and thermal-insulating properties while maintaining a low thickness. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the shortcomings of the existing technology and provide a flame retardant and thermal insulation film based on chopped glass fiber mat reinforcement, which is easy to cut and process, uses less materials, and has both flame retardancy and thermal insulation properties and low thickness, and a preparation method thereof.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0005] A flame-retardant thermal insulation film reinforced with chopped glass fiber mat comprises a ceramic flame-retardant thermal insulation material and chopped glass fiber mat. The ceramic flame-retardant thermal insulation material is immersed in the chopped glass fiber mat and covered on the surface of the chopped glass fiber mat, and is obtained by vulcanization and curing. The ceramic flame-retardant thermal insulation material is mixed with a powder and a base glue. The powder comprises chopped glass fiber powder, the mass of the powder accounts for 25% to 65% of the mass of the base glue, and the chopped glass fiber powder accounts for 10% to 30% of the mass of the powder.

[0006] In the flame-retardant heat-insulating film reinforced with chopped glass fiber mat, preferably, the chopped glass fiber powder accounts for 20% to 30% of the mass of the powder.

[0007] The above-mentioned flame-retardant thermal insulation film reinforced with chopped glass fiber mat, preferably, the powder also includes one or more of zirconium oxide powder, aluminum hydroxide powder, aluminum oxide powder, titanium dioxide powder, zinc borate powder, boron oxide powder, fumed white carbon black, and mica powder; the base rubber is a coated silicone rubber.

[0008] The flame-retardant heat-insulating film reinforced with chopped glass fiber mats mentioned above preferably comprises the following components in parts by mass:

[0009]

[0010] The above-mentioned flame-retardant thermal insulation film reinforced with chopped glass fiber mat, preferably, the ceramicizable flame-retardant thermal insulation material further includes hollow glass microspheres with an average diameter of less than 50 microns, and the mass ratio of the hollow glass microspheres to the powder is 1 to 1.2:20.

[0011] The flame retardant heat insulation film based on the chopped glass fiber mat is preferably made of 250g / m 2 ~600g / m 2 The average length of the fibers in the chopped glass fiber mat is 5 mm to 50 mm; the coating type silicone rubber is a two-component thermosetting silicone rubber with a viscosity of ≤100,000 mPa·s and an elongation of ≥300%.

[0012] As a general technical concept, the present invention also provides a method for preparing the above-mentioned flame-retardant thermal insulation film reinforced with chopped glass fiber mat, comprising the following steps:

[0013] (1) coating a ceramic flame-retardant thermal insulation material on one surface of a chopped glass fiber mat, and applying pressure to penetrate the chopped glass fiber mat through a pressing roller so that the slurry fully penetrates the chopped glass fiber mat without leaking to the back of the chopped glass fiber mat, thereby obtaining a single-sided impregnated chopped glass fiber mat;

[0014] (2) hot vulcanizing and cooling the single-sided impregnated chopped glass fiber mat to obtain a single-sided vulcanized and cured chopped glass fiber mat;

[0015] (3) The other surface of the single-sided vulcanized and cured chopped glass fiber mat is subjected to the dipping step (1) and the vulcanization and curing step (2) to obtain a flame retardant heat-insulating film reinforced with the chopped glass fiber mat.

[0016] In the above preparation method, preferably, the ceramicizable flame-retardant and heat-insulating material is in the form of a slurry with a viscosity of 10 Pa·s to 50 Pa·s.

[0017] In the above preparation method, preferably, in step (1), the coating process is: extruding the ceramicizable flame retardant thermal insulation material onto the surface of the chopped glass fiber mat, and gently coating the surface of the chopped glass fiber mat with a coating head.

[0018] In the above preparation method, preferably, in step (2), the hot vulcanization is to pass the single-sided impregnated chopped glass fiber mat through a straight drying tunnel at a temperature of 50°C to 180°C at a uniform speed.

[0019] The glass fiber mat used in the present invention is quite different from the glass fiber cloth used in the prior art. First of all, the materials of glass fiber cloth and glass fiber mat are different: glass fiber mat is a non-woven material made at high temperature, usually made of glass fiber or other fiber materials; while glass fiber cloth is a fabric, woven from glass fibers. In addition, the production processes of the two materials are different: glass fiber mat is usually manufactured using a non-woven process, which can maintain the high purity of the fiber material; while glass fiber cloth is usually manufactured using a weaving process to obtain a strong fiber structure and a better appearance. As a result, the two materials have different properties. The unique advantages of glass fiber mat are: it is very light and not easy to wear or tear; because it is a non-woven fabric, its fibers can be fixed more tightly together, making the glass fiber mat very dense and strong, and more suitable for bundling, filling and insulation. Because glass fiber cloth is a woven fabric, it is difficult to cut and process, and is more suitable for application scenarios with relatively low cutting and processing requirements, such as construction or shipbuilding.

[0020] Compared with the prior art, the advantages of the present invention are:

[0021] (1) In view of the problem that the existing ceramic polymer anti-insulating materials use fiber cloth as a reinforcing base material or add chopped fibers into the materials, which makes the ceramic polymer anti-insulating materials difficult to cut and process, the production cost is relatively high, and the flame retardant and heat-insulating film materials of the same level are relatively thick, the present invention provides a flame retardant heat-insulating film reinforced with chopped glass fiber mat, which abandons the glass fiber cloth base and glass fiber, and innovatively uses chopped glass fiber mat to reinforce the ceramic flame retardant heat-insulating material, and at the same time adds chopped glass fiber powder into the ceramic flame retardant heat-insulating material. Since the chopped glass fiber mat has a higher density and a denser fiber arrangement, it can use less impregnation amount to achieve the same mechanical strength compared with glass fiber cloth, and the price of glass fiber mat is lower than that of glass fiber cloth. In addition, glass fiber mat is a non-woven fabric, which is easier to cut and process than woven glass fiber cloth. Therefore, the present invention uses glass fiber mat as a reinforcing base material, which can greatly reduce the difficulty of processing and production and the cost of materials while ensuring good mechanical properties. At the same time, the present invention adds chopped glass fiber powder to the ceramic flame retardant thermal insulation material to strengthen the ceramic flame retardant thermal insulation material. Compared with the solution of adding chopped glass fiber to the ceramic flame retardant thermal insulation material, on the one hand, the difficulty of material mixing is reduced, and a common three-roll mixer can be used for mixing. On the other hand, because the addition of chopped glass fiber powder can increase the addition ratio of powder while ensuring the same viscosity of the mixture, and the melting point of glass fiber powder is lower than that of other materials, it is conducive to fusing other materials together to form a strong and tough ceramic layer, and is therefore more conducive to improving key properties such as flame retardancy, fire resistance and thermal insulation. Under the premise of equivalent flame retardancy and thermal insulation performance, the thickness of the film material is smaller. The flame retardant thermal insulation film reinforced by chopped glass fiber mat of the present invention is a fireproof material that is easy to cut, has high strength, high fire resistance temperature and low thickness, and has broad application prospects in the field of fireproof and thermal insulation safety.

[0022] (2) The glass fiber mat used in the present invention has exposed fiber ends on its surface and is prone to falling off, resulting in reduced strength. Therefore, it is not favored by those skilled in the art, which greatly affects its expanded application. In contrast, the field generally uses glass fiber cloth with regular structure and beautiful appearance. The present invention uses ceramic flame-retardant and heat-insulating materials to strengthen and smooth the surface of the glass fiber mat, effectively overcoming the above defects and improving the practicality of the glass fiber mat. The present invention disperses the powder in the base glue. When the base glue containing the powder and the glass fiber mat are exposed to a high temperature of more than 650°C, the -SI-O- bond in the silicone rubber and the powder and the chopped glass fiber mat will ceramicize to form a hard shell, blocking the spread of flames and high temperatures. Too much or too little powder and chopped glass fiber powder are not conducive to the flame retardant and heat-insulating material forming a hard ceramic shell at high temperature. Therefore, the present invention limits the ratio of powder mass to base glue mass to 25% to 65%, and the chopped glass fiber powder accounts for 10% to 30% of the powder mass, which can ensure a better ceramic reaction.

[0023] (3) The preparation method of the present invention is to apply the ceramicizable flame-retardant thermal insulation material to the chopped glass fiber mat and press it, so that the fibers in the glass fiber mat are fully dispersed in the ceramicizable flame-retardant thermal insulation material, so that the material has good mechanical properties. Furthermore, the ceramicizable flame-retardant thermal insulation material is cured in the chopped glass fiber mat and on the surface of the glass fiber mat after vulcanization, so that the surface of the glass fiber mat is repaired and smooth, which can overcome the defects of the glass fiber mat surface having exposed fiber ends and easy fiber shedding, resulting in reduced strength. It can be seen that the chopped glass fiber mat and the ceramicizable flame-retardant thermal insulation material can complement each other through multiple gluing, pressing and vulcanization curing, and have a synergistic reinforcing effect. DETAILED DESCRIPTION

[0024] The present invention will be further described below in conjunction with specific preferred embodiments, but the scope of protection of the present invention is not limited thereby. In the following examples, unless otherwise specified, the raw materials, reagents and instruments used are all commercially available, and the data obtained are the average values of more than three repeated experiments.

[0025] Example 1:

[0026] The present invention provides a flame-retardant thermal insulation film reinforced with chopped glass fiber mat, comprising a ceramic flame-retardant thermal insulation material and chopped glass fiber mat. The ceramic flame-retardant thermal insulation material is immersed in the chopped glass fiber mat and covered on the surface of the chopped glass fiber mat, and is obtained by vulcanization and curing. The ceramic flame-retardant thermal insulation material is mixed with powder and base glue, the mass of the powder is 50% of the mass of the base glue, and the powder includes chopped glass fiber powder, and the chopped glass fiber powder accounts for 25.4% of the mass of the powder.

[0027] In this embodiment, the thickness of the flame retardant thermal insulation film reinforced with chopped glass fiber mat is 0.5 mm.

[0028] In this embodiment, the powder includes, by mass, 3 parts of zirconium oxide powder, 6 parts of aluminum hydroxide powder, 2 parts of aluminum oxide powder, 2 parts of titanium dioxide powder, 5 parts of zinc borate powder, 2 parts of boron oxide powder, 18 parts of fumed white carbon black, 15 parts of mica powder, and 18 parts of chopped glass fiber powder.

[0029] In this embodiment, the ceramic flame retardant thermal insulation material further includes hollow glass microspheres with an average diameter of 40 microns, and the mass ratio of the hollow glass microspheres to the powder is 1:20; the chopped glass fiber mat used is purchased from China Jushi Co., Ltd., model P02, and has a gram weight of 450g / m 2 The average length of the fibers in the chopped glass fiber mat is 25 mm; the chopped glass fiber powder was purchased from Wuhe Weijia Composite Materials Co., Ltd., 200 mesh.

[0030] A method for preparing the flame-retardant thermal insulation film reinforced with chopped glass fiber mat according to the embodiment above comprises the following steps:

[0031] (1) unwinding the chopped glass fiber mat on a coating production line, applying a ceramic flame retardant thermal insulation material to one surface of the unwound chopped glass fiber mat in the form of extruded glue, and performing pressure penetration through a pressing roller. By adjusting the viscosity of the slurry (i.e., the ceramic flame retardant thermal insulation material) to 11 Pa·s, the slurry is fully immersed in the chopped glass fiber mat without leaking to the back of the chopped glass fiber mat, thereby obtaining a single-sided impregnated chopped glass fiber mat;

[0032] (2) passing the single-sided impregnated chopped glass fiber mat through a conveyor belt straight drying tunnel with 7 sections of ovens, each section of 4 meters, and the temperatures of each section are 85°C, 70°C, 110°C, 180°C, 180°C, 180°C, and 50°C for hot vulcanization, and after cooling and curing, obtaining the single-sided vulcanized and cured chopped glass fiber mat, which is then rolled up;

[0033] (3) The other surface of the single-sided vulcanized and cured chopped glass fiber mat is subjected to the dipping step (1), the vulcanization and curing step (2), and cutting to obtain a flame retardant heat-insulating film reinforced with the chopped glass fiber mat.

[0034] In step (1), the preparation steps of the ceramic flame retardant thermal insulation material include:

[0035] (1.1) Weigh 20 kg of powder and 1 kg of hollow glass microspheres and mix them in a mixer. The hollow glass microspheres are GS32 soda-lime borosilicate glass hollow microspheres with an average diameter of 40 μm, which are made from Sinosteel New Materials.

[0036] (1.2) Add 40 kg of low-viscosity thermosetting liquid silicone rubber (purchased from Beijing Dingye Industry and Trade Co., Ltd., model number 5030-6) and 20 kg of xylene solvent into a three-roll mixer. While continuously stirring, slowly add the powder mixed with hollow glass microspheres into the three-roll mixer and mix for 4 hours until completely uniform to obtain a ceramic flame-retardant thermal insulation material. The xylene solvent is used to adjust the viscosity of the slurry so that the slurry does not become compacted or solidified and is easy to penetrate and level with the chopped glass fiber mat.

[0037] In step (1), the glue extrusion is to add the slurry (i.e., ceramicized flame retardant and thermal insulation material) into the feed tank of the casting machine. The height of the scraper needs to be adjusted on the casting machine to ensure the amount of glue applied so that the thickness of the flame retardant and thermal insulation film reinforced with chopped glass fiber mat after pressing, drying and vulcanization is 0.5mm±0.05mm.

[0038] The flame-retardant thermal insulation film reinforced with chopped glass fiber mat prepared in this embodiment was used for the rapid construction of thermal insulation coating for a certain type of rocket. One side was directly sprayed with an oxyacetylene flame at 1300°C, but could not be burned through for 30 minutes, and there was no obvious flame penetration. The temperature of the back side was directly tested to be lower than 600°C.

[0039] Example 2:

[0040] The present invention discloses a flame-retardant thermal insulation film reinforced with chopped glass fiber mat, comprising a ceramic flame-retardant thermal insulation material and chopped glass fiber mat. The ceramic flame-retardant thermal insulation material is immersed in the chopped glass fiber mat and covered on the surface of the chopped glass fiber mat, and is obtained by vulcanization and curing. The ceramic flame-retardant thermal insulation material is mixed with a powder and a base glue, the weight ratio of the powder to the base glue is 50%, and the powder includes chopped glass fiber powder, and the chopped glass fiber powder accounts for 18.5% of the powder mass.

[0041] In this embodiment, the thickness of the flame retardant thermal insulation film reinforced with chopped glass fiber mat is 1.5 mm.

[0042] In this embodiment, the powder includes, by mass, 3 parts of zirconium oxide powder, 6 parts of aluminum hydroxide powder, 2 parts of aluminum oxide powder, 2 parts of titanium dioxide powder, 5 parts of zinc borate powder, 2 parts of boron oxide powder, 18 parts of fumed white carbon black, 15 parts of mica powder, and 12 parts of chopped glass fiber powder.

[0043] In this embodiment, the ceramic flame retardant insulation material further comprises hollow glass microspheres with an average diameter of 50 microns, and the mass ratio of the hollow glass microspheres to the powder is 1:20; the chopped glass fiber mat used is purchased from China Jushi Co., Ltd., model P02, and has a gram weight of 450g / m 2 The average length of the fibers in the chopped glass fiber mat is 25 mm; the chopped glass fiber powder was purchased from Wuhe Weijia Composite Materials Co., Ltd., 200 mesh.

[0044] A method for preparing the flame-retardant thermal insulation film reinforced with chopped glass fiber mat according to the embodiment above comprises the following steps:

[0045] (1) unwinding the chopped glass fiber mat on a coating production line, applying a ceramic flame retardant thermal insulation material to one surface of the unwound chopped glass fiber mat in the form of glue extrusion, and performing pressure penetration through a pressing roller. The viscosity of the ceramic flame retardant thermal insulation material is adjusted to 11 Pa·s by adjusting the slurry so that the slurry fully penetrates the chopped glass fiber mat without leaking to the back of the chopped glass fiber mat, thereby obtaining a single-sided impregnated chopped glass fiber mat;

[0046] (2) passing the single-sided impregnated chopped glass fiber mat through a conveyor belt drying tunnel with 7 sections of ovens, each section of 4 meters, and the temperatures of each section are 85°C, 70°C, 110°C, 180°C, 180°C, 180°C, and 50°C for hot vulcanization, and after cooling and curing, obtaining the single-sided vulcanized and cured chopped glass fiber mat, which is then rolled up;

[0047] (3) The other surface of the single-sided vulcanized and cured chopped glass fiber mat is subjected to the dipping step (1), the vulcanization and curing step (2), and cutting to obtain a flame retardant heat-insulating film reinforced with the chopped glass fiber mat.

[0048] In step (1), the preparation steps of the ceramic flame retardant thermal insulation material include:

[0049] (1.1) Weigh 20 kg of powder and 1 kg of hollow glass microspheres and mix them in a mixer. The hollow glass microspheres are GS46 soda-lime borosilicate glass hollow microspheres with an average diameter of 50 μm, produced by Sinosteel New Materials.

[0050] (1.2) Add 40 kg of low-viscosity thermosetting liquid silicone rubber (purchased from Beijing Dingye Industry and Trade Co., Ltd., model number 5030-6) and 10 kg of xylene solvent into a three-roll mixer. While stirring continuously, slowly add the powder mixed with hollow glass microspheres into the three-roll mixer and mix for 4 hours until completely uniform. The xylene solvent is used to adjust the viscosity of the slurry so that the slurry does not become compacted or solidified, and is easy to better penetrate and level with the chopped glass fiber mat.

[0051] In step (1), the glue extrusion is to add the slurry (i.e., ceramicized flame retardant and thermal insulation material) into the feed tank of the casting machine. The height of the scraper needs to be adjusted on the casting machine to ensure the amount of glue applied so that the thickness of the flame retardant and thermal insulation film reinforced with chopped glass fiber mat after pressing, drying and vulcanization is 1.2mm±0.05mm.

[0052] The flame-retardant thermal insulation film reinforced with chopped glass fiber mat prepared in this embodiment was used for the rapid construction of a ternary lithium battery for a new energy vehicle. One side was directly sprayed with an oxyacetylene flame at 1300°C, but could not be burned through for 30 minutes, and there was no obvious flame penetration. The temperature of the back side was directly tested to be lower than 650°C.

[0053] Example 3:

[0054] The present invention discloses a flame-retardant thermal insulation film reinforced with chopped glass fiber mat, comprising a ceramic flame-retardant thermal insulation material and chopped glass fiber mat. The ceramic flame-retardant thermal insulation material is immersed in the chopped glass fiber mat and covered on the surface of the chopped glass fiber mat, and is obtained by vulcanization and curing. The ceramic flame-retardant thermal insulation material is mixed with a powder and a base glue, the weight ratio of the powder to the base glue is 50%, and the powder includes chopped glass fiber powder, and the chopped glass fiber powder accounts for 10.2% of the powder mass.

[0055] In this embodiment, the thickness of the flame retardant thermal insulation film reinforced with chopped glass fiber mat is 1.2 mm.

[0056] In this embodiment, the powder includes, by mass, 3 parts of zirconium oxide powder, 6 parts of aluminum hydroxide powder, 2 parts of aluminum oxide powder, 2 parts of titanium dioxide powder, 5 parts of zinc borate powder, 2 parts of boron oxide powder, 18 parts of fumed white carbon black, 15 parts of mica powder, and 6 parts of chopped glass fiber powder.

[0057] In this embodiment, the ceramic flame retardant insulation material further comprises hollow glass microspheres with an average diameter of 50 microns, and the mass ratio of the hollow glass microspheres to the powder is 1:20; the chopped glass fiber mat used is purchased from China Jushi Co., Ltd., model P02, and has a gram weight of 450g / m 2 The average length of the fibers in the chopped glass fiber mat is 25 mm; the chopped glass fiber powder was purchased from Wuhe Weijia Composite Materials Co., Ltd., 200 mesh.

[0058] A method for preparing the flame-retardant thermal insulation film reinforced with chopped glass fiber mat according to the embodiment above comprises the following steps:

[0059] (1) unwinding the chopped glass fiber mat on a coating production line, applying a ceramic flame retardant thermal insulation material to one surface of the unwound chopped glass fiber mat in the form of glue extrusion, and performing pressure penetration through a pressing roller. The viscosity of the ceramic flame retardant thermal insulation material is adjusted to 11 Pa·s by adjusting the slurry so that the slurry fully penetrates the chopped glass fiber mat without leaking to the back of the chopped glass fiber mat, thereby obtaining a single-sided impregnated chopped glass fiber mat;

[0060] (2) passing the single-sided impregnated chopped glass fiber mat through a conveyor belt drying tunnel with 7 sections of ovens, each section of 4 meters, and the temperatures of each section are 85°C, 70°C, 110°C, 180°C, 180°C, 180°C, and 50°C for hot vulcanization, and after cooling and curing, obtaining the single-sided vulcanized and cured chopped glass fiber mat, which is then rolled up;

[0061] (3) The other surface of the single-sided vulcanized and cured chopped glass fiber mat is subjected to the dipping step (1), the vulcanization and curing step (2), and cutting to obtain a flame retardant heat-insulating film reinforced with the chopped glass fiber mat.

[0062] In step (1), the preparation steps of the ceramic flame retardant thermal insulation material include:

[0063] (1.1) Weigh 20 kg of powder and 1 kg of hollow glass microspheres and mix them in a mixer. The hollow glass microspheres are GS40 soda lime borosilicate hollow glass microspheres with an average diameter of 50 μm, which are produced by Sinosteel New Materials.

[0064] (1.2) Add 40 kg of low-viscosity thermosetting liquid silicone rubber (purchased from Beijing Dingye Industry and Trade Co., Ltd., model 5030-6) and 18 kg of xylene solvent into a three-roll mixer. Slowly add the powder mixed with hollow glass microspheres into the three-roll mixer and mix for 3 hours until completely uniform. The solvent xylene is used to adjust the viscosity of the slurry so that the slurry does not become compacted or solidified, and is easy to better penetrate and level with the chopped glass fiber mat.

[0065] In step (1), the glue extrusion is to add the slurry (i.e., ceramicized flame retardant and thermal insulation material) into the feed tank of the casting machine. The height of the scraper needs to be adjusted on the casting machine to ensure the amount of glue applied so that the thickness of the flame retardant and thermal insulation film reinforced with chopped glass fiber mat after pressing, drying and vulcanization is 1.2mm±0.05mm.

[0066] The flame-retardant thermal insulation film reinforced with chopped glass fiber mat prepared in this embodiment was used for the rapid construction of thermal insulation coating for a ternary lithium battery of a new energy vehicle. One side was directly sprayed with an oxyacetylene flame at 1300°C using an Iwatani spray gun. The film could not be burned through in 30 minutes, and there was no obvious flame penetration. The temperature of the back side was directly tested to be lower than 700°C.

[0067] Compared with similar materials using glass fiber cloth as a base material, the prepared reinforced ceramic flame retardant thermal insulation material not only improves the flame retardant properties and ensures mechanical strength, but also reduces the difficulty of subsequent material cutting and shortens the overall working hours.

[0068] Comparative Example 1:

[0069] A flame-retardant thermal insulation film reinforced with chopped glass fiber cloth was essentially the same as Example 1, differing only in that chopped glass fiber cloth, model EWR400E, was used as the reinforcing substrate. The resulting flame-retardant thermal insulation film reinforced with chopped glass fiber cloth had a thickness of 0.5 mm.

[0070] The flame-retardant thermal insulation film reinforced with chopped glass fiber cloth prepared in this comparative example was used for the rapid construction of a ternary lithium battery for a new energy vehicle. One side was directly sprayed with an oxyacetylene flame at 1300°C, and the temperature of the back side was directly tested to be lower than 710°C.

[0071] Adding chopped glass fiber powder to the powder constituting the ceramic flame retardant thermal insulation material reduces the difficulty of material mixing compared to the solution of adding chopped glass fiber to the ceramic flame retardant thermal insulation material, and an ordinary three-roll mixer can be used for mixing. On the other hand, because no chopped glass fiber component is added (the present invention adds chopped glass fiber powder), the addition ratio of the powder can be increased while ensuring the same mixture viscosity, thereby improving key properties such as flame retardancy, fire resistance and thermal insulation.

[0072] Comparative Example 2:

[0073] A flame-retardant thermal insulation film reinforced with chopped glass fiber mat is essentially the same as Example 1, differing only in that the chopped glass fiber powder in the powder is replaced with 6mm chopped glass fibers purchased from Cangzhou Zhongli New Material Technology Co., Ltd. The resulting flame-retardant thermal insulation film reinforced with chopped glass fiber mat has a thickness of 0.5 mm.

[0074] The flame-retardant thermal insulation film reinforced with chopped glass fiber mat prepared in this comparative example was used for the rapid construction of a ternary lithium battery for a new energy vehicle. One side was directly sprayed with an oxyacetylene flame at 1300°C, and the back side was directly tested to a temperature below 660°C.

[0075] Table 1 Summary of properties of flame retardant thermal insulation films of Examples 1-3 and Comparative Examples

[0076]

[0077]

[0078] As can be seen from Table 1, compared with the 25.4% of the powder mass of the chopped glass fiber powder used in Example 1, the chopped glass fiber powder in Examples 2 and 3 accounted for 18.5% and 10.2% of the powder mass respectively. From the results of the spraying test and the back temperature test, it can be seen that the thickness of the flame retardant and thermal insulation films of Examples 2 and 3 must be more than twice that of Example 1 to achieve the same burning resistance as Example 1. It can be seen that at the same thickness, its burning resistance is not as good as Example 1, and even with more than twice the thickness, the back temperature of Examples 2-3 is still higher than that of Example 1, which proves that the amount of chopped glass fiber powder in the present invention has an important influence on the flame retardant and thermal insulation properties of the flame retardant and thermal insulation film.

[0079] Compared with Example 1, Comparative Example 1 uses chopped glass fiber cloth as the reinforcing substrate. At the same thickness, the flame-retardant thermal insulation film of Comparative Example 1 has comparable burn resistance to the flame-retardant thermal insulation film reinforced with chopped glass fiber mat in Example 1, but its backside test temperature is significantly higher. Similarly, Comparative Example 2 replaces the chopped glass fiber powder in Example 1 with chopped glass fiber. The resulting film has comparable burn resistance to Example 1, and its backside test temperature is also significantly higher than that of Example 1. This indicates that the chopped glass fiber mat and chopped glass fiber powder used in the present invention can effectively improve the thermal insulation performance of the resulting film. This is because the flame-retardant thermal insulation film reinforced with chopped glass fiber mat can be rapidly sintered under high-temperature flames, preventing flame penetration, and the backside temperature of the flame-retardant thermal insulation film is relatively low. In practical applications, the lower back temperature of flame-retardant insulation film is of great significance. For example, in new energy vehicles, especially those equipped with ternary lithium batteries, the flame temperature can reach 1300°C when the battery burns, while the auto-ignition point of automotive interior parts such as PVC, PP, PE, and PU does not exceed 380°C. If there are no proper fire-retardant measures, once the battery thermal runaway, the occupants will have almost no time to escape. The use of flame-retardant insulation film with a lower back burning temperature in combination with the battery shell and the bottom shell can slow down the temperature rise inside the car, extend the time it takes for the automotive interior parts to reach the auto-ignition point, and gain more time for the occupants to escape.

[0080] The above description is only a preferred embodiment of the present invention and does not constitute any formal limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the spirit and technical solution of the present invention, use the methods and technical contents disclosed above to make many possible changes and modifications to the technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention, still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A flame retardant thermal insulation film reinforced with chopped glass fiber mat, characterized in that: The invention comprises a ceramic flame-retardant thermal insulation material and chopped glass fiber mat. The ceramic flame-retardant thermal insulation material is immersed in the chopped glass fiber mat and covered on the surface of the chopped glass fiber mat, and is obtained by vulcanization and curing. The ceramic flame-retardant thermal insulation material is mixed with a powder and a base glue. The powder includes chopped glass fiber powder. The mass of the powder accounts for 25% to 65% of the mass of the base glue, and the chopped glass fiber powder accounts for 10% to 30% of the mass of the powder.

2. The flame retardant thermal insulation film reinforced with chopped glass fiber mat according to claim 1, characterized in that: The chopped glass fiber powder accounts for 20% to 30% of the powder mass.

3. The flame retardant thermal insulation film reinforced with chopped glass fiber mat according to claim 2, characterized in that: The powder further comprises one or more of zirconium oxide powder, aluminum hydroxide powder, aluminum oxide powder, titanium dioxide powder, zinc borate powder, boron oxide powder, fumed white carbon black, and mica powder; and the base rubber is a coating type silicone rubber.

4. The flame retardant thermal insulation film reinforced with chopped glass fiber mat according to claim 3, characterized in that: The powder composition ratio includes, by mass:

5. The flame retardant thermal insulation film reinforced with chopped glass fiber mat according to claim 4, characterized in that: The ceramicizable flame-retardant heat-insulating material further comprises hollow glass microspheres with an average diameter of less than 50 micrometers, and the mass ratio of the hollow glass microspheres to the powder is 1 to 1.2:

20.

6. The flame retardant thermal insulation film reinforced with chopped glass fiber mat according to claim 5, characterized in that: The gram weight of the chopped glass fiber mat is 250g / m 2 ~600g / m 2 The average length of the fibers in the chopped glass fiber mat is 5 mm to 50 mm; the coating type silicone rubber is a two-component thermosetting silicone rubber with a viscosity of ≤100,000 mPa·s and an elongation of ≥300%.

7. A method for preparing a flame-retardant thermal insulation film reinforced with chopped glass fiber mat according to any one of claims 1 to 6, characterized in that: The following steps are involved: (1) coating a ceramic flame-retardant thermal insulation material on one surface of a chopped glass fiber mat, and applying pressure to penetrate the chopped glass fiber mat through a pressing roller so that the slurry fully penetrates the chopped glass fiber mat without leaking to the back of the chopped glass fiber mat, thereby obtaining a single-sided impregnated chopped glass fiber mat; (2) hot vulcanizing and cooling the single-sided impregnated chopped glass fiber mat to obtain a single-sided vulcanized and cured chopped glass fiber mat; (3) The other surface of the single-sided vulcanized and cured chopped glass fiber mat is subjected to the dipping step (1) and the vulcanization and curing step (2) to obtain a flame retardant heat-insulating film reinforced with the chopped glass fiber mat.

8. The preparation method according to claim 7, characterized in that The ceramicizable flame-retardant heat-insulating material is in a slurry form and has a viscosity of 10 Pa·s to 50 Pa·s.

9. The preparation method according to claim 8, characterized in that In step (1), the coating process is as follows: the ceramicizable flame retardant heat insulating material is squeezed onto the surface of the chopped glass fiber mat, and is smoothly coated on the surface of the chopped glass fiber mat through a coating head.

10. The preparation method according to claim 8, characterized in that In step (2), the hot vulcanization is to pass the single-sided impregnated chopped glass fiber mat through a straight drying tunnel with a temperature of 50°C to 180°C at a uniform speed.

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