High-air-tightness flame-retardant gas film building material and preparation method thereof

Abstract

According to the high-airtightness flame-retardant gas film building material and the preparation method thereof, collaborative optimization of airtightness, flame retardance, weather resistance, mechanical property and processability is achieved through the raw materials and the preparation method, the use requirements of harsh scenes are met, the service life of the material is prolonged, and the operation cost and the whole life cycle cost are reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of air film building materials, in particular to a high-air-tightness flame-retardant air film building material and a preparation method thereof. BACKGROUND

[0002] Air film building is a large-span space structure formed by using high-strength flexible film material as an "outer shell" and being supported by internal air pressure. Air film building has the advantages of large span, short construction period, and high space utilization rate, and its demand continues to grow in the field of large public buildings and special industrial facilities. The current mainstream air film building materials include single PVDF film and PVC composite film. These air film building materials mainly have the following problems in use: First, the air tightness is insufficient. For example, air film building materials that rely on single film structure or simple coating process have difficulty in controlling the porosity, which is prone to have high porosity and large gas permeability, resulting in frequent pressure compensation of the air film building and the risk of structural collapse caused by sudden air pressure drop. Second, the flame retardant performance grade is low, and molten material may drop during combustion, which easily leads to flame spread. For example, PVC composite film rapidly melts and shrinks under open flame, and cannot form an effective barrier. Third, the weather resistance is poor. Single PVDF film and PVC composite film are prone to performance degradation under long-term ultraviolet radiation and high-low temperature cycles. After 5-8 years of outdoor use, they are prone to cracking, discoloration, and mechanical failure, so they need to be replaced frequently, resulting in high life cycle cost. Fourth, the mechanical properties and processability are unbalanced. For example, increasing the thickness of the air film building or increasing the inorganic filler in the air film material to improve the tensile strength of the air film material will result in a decrease in processing flowability, which will easily cause problems such as bubbles, poor thickness uniformity during extrusion, and air film tearing under external forces such as strong wind and snow.

[0003] Therefore, it is of great significance to provide an air film building material with high air tightness, high flame retardancy, excellent weather resistance, and mechanical properties, and good processability. SUMMARY

[0004] In view of this, the present application provides a high-air-tightness flame-retardant air film building material and a preparation method thereof. The raw materials and preparation method of the present application realize the synergistic optimization of air tightness, flame retardancy, weather resistance, mechanical properties, and processability, meet the use requirements of harsh scenes, prolong the service life of the material, and reduce the operation and life cycle cost.

[0005] The technical solution of the present application is as follows: A high-air-tightness flame-retardant air film building material comprises the following components by weight: Polytetrafluoroethylene 60-80 parts, polyvinylidene fluoride 20-40 parts, red phosphorus 2-4 parts, graphene oxide 5-9 parts, silver nanoparticles 3-4 parts, chitosan 1-3 parts, nano-magnesium stearate 3-5 parts, silane coupling agent 1-2 parts, antioxidant 0.5-1 parts, plasticizer 2-5 parts.

[0006] Preferably, the high-air-tightness flame-retardant gas film building material comprises the following components by weight: Polytetrafluoroethylene 70 parts, polyvinylidene fluoride 30 parts, red phosphorus 3 parts, graphene oxide 6 parts, silver nanoparticles 3.5 parts, chitosan 1.5 parts, nano-magnesium stearate 4 parts, silane coupling agent 1.5 parts, antioxidant 0.8 parts, plasticizer 4 parts.

[0007] Preferably, the silane coupling agent is KH-560; the antioxidant is antioxidant 1010; and the plasticizer is DOP.

[0008] A preparation method of a high-air-tightness flame-retardant gas film building material, the process being as follows: Step one, dry the polytetrafluoroethylene and polyvinylidene fluoride particles in a vacuum oven at 75-85°C for 4-5h to remove moisture and reduce the generation of bubbles during processing; Step two, add graphene oxide, silver nanoparticles and nano-magnesium stearate into N, N-dimethylformamide and ultrasonically treat for 30-50min to obtain a suspension; wherein the total weight of graphene oxide, silver nanoparticles and nano-magnesium stearate to the weight of N, N-dimethylformamide is 1:20-30; Step three, coat the red phosphorus with chitosan to obtain a coated product; this process can both avoid moisture absorption of red phosphorus and improve its compatibility with polymers; Step four, put the dried polytetrafluoroethylene and polyvinylidene fluoride of step one into a reaction kettle, then add N-dimethylformamide and continuously stir at 60-70°C until dissolved to obtain a transparent viscous glue solution; wherein the total weight of polytetrafluoroethylene and polyvinylidene fluoride to the weight of N-dimethylformamide is 1:5-7; Step five, add the suspension of step two, the coated product of step three, the silane coupling agent, the antioxidant and the plasticizer into the glue solution of step four in sequence, shear treat at 3000-5000rpm for 1-2h to make the components uniformly dispersed; then add the remaining chitosan thereto and stir at 100rpm for 30-40min to obtain a mixture A; Step six, send the mixture A to the vacuum degassing tank, remove the air bubbles involved in the stirring process under the vacuum degree of -0.1 MPa until no air bubbles escape from the surface of the slurry, and obtain the mixture B; the processing process can avoid the adverse effects of air bubbles on the density and optical uniformity of the material, and improve the quality of the air film building material; Step seven, uniformly coat the mixture B on the clean release paper through the die head of the casting machine; then treat it at 80±0.5℃ for 2-3h and at 130-150℃ for 1-2h; after complete drying, peel off, cool and wind up to obtain the product; in this process, the lower temperature treatment first can avoid the influence of rapid solvent evaporation on the density of the material; then high temperature treatment can speed up the solvent evaporation speed and promote the crosslinking reaction of the alkyl coupling agent, so that the interface between the polymer matrix and the inorganic filler is more firmly combined.

[0009] Preferably, in step three, the coating process is as follows: S1, take part of chitosan, dissolve it in 1.5% (v / v) acetic acid solution, and stir until dissolved to form a clear and viscous chitosan acetic acid solution; Wherein, the weight of chitosan is 20% of the weight of red phosphorus; the weight ratio of chitosan to acetic acid solution is 1:6-10; S2, add sodium dodecyl sulfate to deionized water and stir to dissolve; then slowly add red phosphorus to it, and after adding, stir at 500 rpm to wet and disperse the red phosphorus; then high-speed shear disperse at 10000 rpm for 45-60 min to obtain slurry A; Wherein, the weight ratio of red phosphorus to deionized water is 1:6-10, and the weight ratio of red phosphorus to sodium dodecyl sulfate is 200-220:1; S3, adjust the stirring speed to 500 rpm and heat the slurry A to 50±0.5℃, then slowly drop the chitosan acetic acid solution into the slurry A, continue to stir for 1.5-2h after dropping, so that the chitosan is combined with the red phosphorus to obtain slurry B; S4, drop 10% (v / v) glutaraldehyde aqueous solution into slurry B under stirring, and continue to stir for 1-1.5h after dropping to obtain slurry C; Wherein, the weight ratio of glutaraldehyde aqueous solution to red phosphorus is 1:5-6; S5, adjust the pH of slurry C to 8.5-8.7 using 1 mol / L NaOH solution, and then continue to react for 3-4h to obtain slurry D; S6, after cooling and filtering the slurry D, collect the filter cake; after washing and drying the filter cake, obtain the coated product.

[0010] In the application, polytetrafluoroethylene is used as the main film-forming material, and the molecular chain of polytetrafluoroethylene has high rigidity and high crystallinity, and can form a very dense film with very low porosity; after blending with PVDF, the processing difficulty of PTFE is improved, and good film-forming property and mechanical property are provided; wherein, based on the PTFE / PVDF dense matrix, the graphene oxide constructs a nanoscale physical barrier path, the silane coupling agent eliminates the interface defects, and the three are synergistically realized to achieve very low gas permeability, so as to ensure the denseness of the gas film building material; in the combustion process, the red phosphorus decomposes, promotes the formation of a dense protective carbon layer by the graphene oxide and chitosan, and the silver nanoparticles assist heat conduction, and a multiple synergistic flame-retardant mechanism of condensed phase, gas phase and cooling is formed.

[0011] Compared with the prior art, the application has the following beneficial effects: The building material has high denseness and flame retardancy; by using the synergistic effect of the components, the air tightness, flame retardancy, weather resistance, mechanical property and processability of the gas film building material are synergistically optimized, and the effect is remarkable. DETAILED DESCRIPTION

[0012] In order to enable the personnel in the technical field to better understand the technical solutions in the application, the technical solutions in the application will be clearly and completely described below in combination with the embodiments of the application. Obviously, the described embodiments are only some of the embodiments of the application, not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by the personnel in the field without creative labor should belong to the protection scope of the application.

[0013] Embodiment 1 A high air tightness flame retardant gas film building material comprises the following components in parts by weight: polytetrafluoroethylene 70 parts, polyvinylidene fluoride 30 parts, red phosphorus 3 parts, graphene oxide 6 parts, silver nanoparticles 3.5 parts, chitosan 1.5 parts, nano-magnesium stearate 4 parts, silane coupling agent 1.5 parts, antioxidant 0.8 parts, plasticizer 4 parts; The silane coupling agent is KH-560; the antioxidant is antioxidant 1010; and the plasticizer is DOP; The preparation method of the above high air tightness flame retardant gas film building material is as follows: Step one, dry the polytetrafluoroethylene and polyvinylidene fluoride particles in a vacuum oven at 80 DEG C for 4.5 h to remove water and reduce the generation of bubbles in the processing process; Step two, add graphene oxide, silver nanoparticles and nano-magnesium stearate into N, N-dimethylformamide, and ultrasonic treat for 40 min to obtain a suspension; The total weight of graphene oxide, silver nanoparticles and nano-magnesium stearate and the weight of N, N-dimethylformamide are in a ratio of 1:25; Step three, using chitosan to coat red phosphorus, to obtain the coated product; this process can not only avoid the hygroscopicity of red phosphorus, but also improve its compatibility with polymers; The coating process is as follows: S1, take part of chitosan, dissolve in 1.5% (v / v) acetic acid solution, stir until dissolved, form clear, viscous chitosan acetic acid solution; The weight of chitosan is 20% of the weight of red phosphorus; the weight ratio of chitosan to acetic acid solution is 1:8; S2, add sodium dodecyl sulfate to deionized water, stir to dissolve; then slowly add red phosphorus, after adding, stir at 500 rpm, make the red phosphorus wet and dispersed; then high-speed shear dispersion at 10000 rpm for 55 min, to obtain slurry A; The weight ratio of red phosphorus to deionized water is 1:9, and the weight ratio of red phosphorus to sodium dodecyl sulfate is 210:1; S3, adjust the stirring speed to 500 rpm, and heat slurry A to 50±0.5℃, then slowly drop the chitosan acetic acid solution into slurry A, continue to stir for 1.8 h after dropping, make chitosan combine with red phosphorus, to obtain slurry B; S4, under the condition of stirring, drop 10% (v / v) glutaraldehyde aqueous solution into slurry B, after dropping, continue to stir for 1.3 h, to obtain slurry C; The weight ratio of glutaraldehyde aqueous solution to red phosphorus is 1:5.5; S5, use 1 mol / L NaOH solution to adjust the pH of slurry C to 8.6, then continue to react for 3.5 h, to obtain slurry D; S6, after cooling and filtering slurry D, collect the filter cake; after washing and drying the filter cake, obtain the coated product; Step four, put the dried polytetrafluoroethylene and polyvinylidene fluoride in step one into the reaction kettle, then add N-dimethylformamide, continue to stir at 65℃ until dissolved, to obtain transparent viscous glue solution; The total weight of polytetrafluoroethylene and polyvinylidene fluoride and the weight of N-dimethylformamide are in a ratio of 1:6; Step five, add the suspension of step two, the coated product of step three, silane coupling agent, antioxidant and plasticizer into the glue solution of step four in turn, shear at 4000 rpm for 1.5 h, to make each component uniformly dispersed; then add the remaining chitosan, stir at 100 rpm for 35 min, to obtain mixture A; Step six, send the mixed material A to the vacuum degassing tank, remove the air bubbles involved in the stirring process under the vacuum degree of-0.1 MPa until no air bubbles escape from the surface of the slurry, and obtain mixed material B; this process can avoid the adverse effects of air bubbles on the density and optical uniformity of the material and improve the quality of the air film building material; Step seven, uniformly coat the mixed material B on the clean release paper through the die head of the casting machine; then treat it at 80±0.5℃ for 2.5h and at 140℃ for 1.5h; after complete drying, peel off, cool and roll up to obtain the product; in this process, the lower temperature treatment first avoids the influence of rapid solvent evaporation on the density of the material; then high temperature treatment accelerates the solvent evaporation speed and promotes the crosslinking reaction of the alkyl coupling agent, making the interface between the polymer matrix and the inorganic filler more firmly bonded.

[0014] Example 2 A high-air-tightness flame-retardant air film building material, comprising the following components in parts by weight: 60 parts of polytetrafluoroethylene, 40 parts of polyvinylidene fluoride, 2 parts of red phosphorus, 5 parts of graphene oxide, 3 parts of silver nanoparticles, 1 part of chitosan, 3 parts of nano-magnesium stearate, 1 part of silane coupling agent, 0.5 parts of antioxidant, and 2 parts of plasticizer; The silane coupling agent is KH-560; the antioxidant is antioxidant 1010; and the plasticizer is DOP; The preparation method of the above high-air-tightness flame-retardant air film building material is as follows: Step one, dry the polytetrafluoroethylene and polyvinylidene fluoride particles in a vacuum oven at 75℃ for 5h to remove moisture and reduce the generation of air bubbles during processing; Step two, add graphene oxide, silver nanoparticles and nano-magnesium stearate into N, N-dimethylformamide and ultrasonically treat for 30min to obtain a suspension; The total weight of graphene oxide, silver nanoparticles and nano-magnesium stearate is 1:30 of the weight of N, N-dimethylformamide; Step three, perform coating treatment on the red phosphorus using chitosan to obtain a coated product; this process can avoid moisture absorption of red phosphorus and improve its compatibility with polymers; The coating process is as follows: S1, take part of chitosan, dissolve it in 1.5% (v / v) acetic acid solution, stir until dissolved, and form a clear and viscous chitosan acetic acid solution; The weight of chitosan is 20% of the weight of red phosphorus; and the weight ratio of chitosan to acetic acid solution is 1:6; S2, sodium dodecyl sulfate was added into deionized water, and stirred to dissolve; then red phosphorus was slowly added into the solution, and after the addition, the red phosphorus was wetted and dispersed under the condition of 500 rpm stirring; then the red phosphorus was dispersed at high speed under the condition of 10000 rpm for 45 min, to obtain slurry A; wherein the weight ratio of red phosphorus to deionized water is 1:10, and the weight ratio of red phosphorus to sodium dodecyl sulfate is 220:1; S3, the stirring speed was adjusted to 500 rpm, and the slurry A was heated to 50±0.5℃, then the chitosan acetic acid solution was slowly added into the slurry A, after the addition, the stirring was continued for 1.5 h, so that the chitosan was combined with the red phosphorus, to obtain slurry B; S4, 10% (v / v) glutaraldehyde aqueous solution was added into the slurry B under stirring, after the addition, the stirring was continued for 1.5 h, to obtain slurry C; wherein the weight ratio of glutaraldehyde aqueous solution to red phosphorus is 1:5; S5, the pH of the slurry C was adjusted to 8.5 using 1 mol / L NaOH solution, and then the reaction was continued for 3-4 h, to obtain slurry D; S6, after the slurry D was cooled and filtered, the filter cake was collected; after the filter cake was washed and dried, the coating product was obtained; Step four, the dried polytetrafluoroethylene and polyvinylidene fluoride in step one were put into a reaction kettle, then N-dimethylformamide was added, and the stirring was continued at 60℃ until the solution was dissolved, to obtain a transparent viscous glue solution; wherein the weight ratio of the total weight of polytetrafluoroethylene and polyvinylidene fluoride to the weight of N-dimethylformamide is 1:5; Step five, the suspension in step two, the coating product in step three, the silane coupling agent, the antioxidant, and the plasticizer were sequentially added into the glue solution in step four, and the shearing treatment was carried out at 3000 rpm for 1 h, so that the components were uniformly dispersed; then the remaining chitosan was added, and the stirring was carried out at 100 rpm for 30 min, to obtain mixture A; Step six, the mixture A was sent to a vacuum degassing tank, and the air bubbles involved in the stirring process were removed under the vacuum degree of-0.1 MPa, until no air bubbles escaped from the surface of the slurry, to obtain mixture B; this treatment process can avoid the adverse effects of air bubbles on the compactness and optical uniformity of the material, and improve the quality of the air film building material; Step seven, the mixed material B is coated on the clean release paper through the flow casting machine cutter head, and then is treated at 80±0.5℃ for 2h and at 130℃ for 2h; after complete drying, peeling, cooling and winding are carried out to obtain the product; in the treatment, the method of treating at a lower temperature first can avoid the influence of the rapid evaporation of the solvent on the compactness of the material; then high-temperature treatment is adopted to accelerate the evaporation speed of the solvent and promote the cross-linking reaction of the alkane coupling agent, so that the interface between the polymer matrix and the inorganic filler is combined more firmly.

[0015] Example 3 A high-air-tightness flame-retardant gas film building material comprises the following components in parts by weight: 80 parts of polytetrafluoroethylene, 20 parts of polyvinylidene fluoride, 4 parts of red phosphorus, 9 parts of graphene oxide, 4 parts of silver nanoparticles, 3 parts of chitosan, 5 parts of nano-magnesium stearate, 2 parts of silane coupling agent, 1 part of antioxidant, and 5 parts of plasticizer; The silane coupling agent is KH-560, the antioxidant is antioxidant 1010, and the plasticizer is DOP. The preparation method of the above high-air-tightness flame-retardant gas film building material is as follows: Step one, dry the polytetrafluoroethylene and polyvinylidene fluoride particles in a vacuum oven at 85℃ for 4h to remove moisture and reduce the generation of bubbles in the processing process; Step two, add graphene oxide, silver nanoparticles and nano-magnesium stearate into N, N-dimethylformamide and ultrasonically treat for 50min to obtain a suspension; The total weight of graphene oxide, silver nanoparticles and nano-magnesium stearate is 1:20 of the weight of N, N-dimethylformamide. Step three, perform coating treatment on the red phosphorus using chitosan to obtain a coated product; this process can avoid moisture absorption of the red phosphorus and improve the compatibility of the red phosphorus with the polymer. The coating treatment process is as follows: S1, take part of chitosan, dissolve it in 1.5% (v / v) acetic acid solution, stir until dissolved, and form a clear and viscous chitosan acetic acid solution; The weight of chitosan is 20% of the weight of red phosphorus, and the weight ratio of chitosan to acetic acid solution is 1:10. S2, add sodium dodecyl sulfate to deionized water and stir until dissolved; then slowly add red phosphorus to the solution, stir at 500rpm after adding, wet and disperse the red phosphorus; then high-speed shear disperse at 10000rpm for 60min to obtain slurry A; The weight ratio of red phosphorus to deionized water is 1:6, and the weight ratio of red phosphorus to sodium dodecyl sulfate is 200:1. S3, adjust the stirring speed to 500 rpm, and heat the slurry A to 50±0.5℃, then slowly drop the chitosan acetic acid solution into the slurry A, after dropping, continue to stir for 2h, so that the chitosan is combined with the red phosphorus to obtain slurry B; S4, under the condition of stirring, drop 10% (v / v) glutaraldehyde aqueous solution into the slurry B, after dropping, continue to stir for 1h to obtain slurry C; The weight ratio of the glutaraldehyde aqueous solution to the red phosphorus is 1:6. S5, use 1 mol / L NaOH solution to adjust the pH of the slurry C to 8.7, then continue to react for 3-4h to obtain slurry D; S6, after cooling and filtering the slurry D, collect the filter cake; after washing and drying the filter cake, obtain the coating product; Step four, put the polytetrafluoroethylene and polyvinylidene fluoride dried in step one into the reaction kettle, then add N-dimethylformamide, continuously stir at 70℃ until dissolved to obtain a transparent viscous glue solution; The weight ratio of the total weight of the polytetrafluoroethylene and the polyvinylidene fluoride to the weight of the N-dimethylformamide is 1:7. Step five, add the suspension of step two, the coating product of step three, the silane coupling agent, the antioxidant, and the plasticizer into the glue solution of step four in sequence, and shear at 5000 rpm for 1h to make the components uniformly dispersed; then add the remaining chitosan, and stir at 100 rpm for 40 min to obtain a mixture A; Step six, send the mixture A to a vacuum degassing tank, and remove the air bubbles involved in the stirring process under a vacuum degree of -0.1 MPa until no air bubbles escape from the surface of the slurry to obtain a mixture B; this treatment process can avoid the adverse effects of air bubbles on the density and optical uniformity of the material, and improve the quality of the air film building material; Step seven, pass the mixture B through the knife head of a flow coater to uniformly coat it on clean release paper; then treat it at 80±0.5℃ for 3h and at 150℃ for 1h; after complete drying, peel off, cool, and wind up to obtain a product; in this treatment, the lower temperature treatment first avoids the influence of rapid solvent evaporation on the density of the material; then high temperature treatment accelerates the solvent evaporation speed and promotes the crosslinking reaction of the silane coupling agent, making the interface between the polymer matrix and the inorganic filler more firmly bonded.

[0016] Test the materials obtained in Examples 1-3, and the results are shown in Table 1 as follows: Table 1 Test results

[0017] Among them, Air tightness, GB / T 1038-2000 "Plastic films and sheets-determination of gas transmission rate-differential pressure method"; Flame retardancy, GB / T 2408-2021 "Determination of the flammability of plastic materials, horizontal and vertical method"; Weather resistance, GB / T 16422.2-2022 "Plastics - Laboratory light exposure tests - Part 2: Xenon arc lamps"; Tensile strength and elongation at break, GB / T 1040.3-2006 "Determination of tensile properties of plastics - Part 3: test conditions for films and sheets".

[0018] Although the present application has been described in detail by reference to preferred embodiments, the application is not limited to such preferred embodiments. Without departing from the spirit and essential characteristics of the application, various equivalent modifications and substitutions can be made by those skilled in the art. Such modifications and substitutions are intended to fall within the scope of the application. Any changes or modifications that come within the spirit of the application are to be considered as falling within the four corners of the application as contemplated by the inventors. Accordingly, the patentable scope of the application is defined by the appended claims.

Claims

1. A high air barrier, flame retardant air film building material, characterized in that, Comprise the following components by weight: Polytetrafluoroethylene 60-80 parts, polyvinylidene fluoride 20-40 parts, red phosphorus 2-4 parts, graphene oxide 5-9 parts, silver nanoparticles 3-4 parts, chitosan 1-3 parts, nano magnesium stearate 3-5 parts, silane coupling agent 1-2 parts, antioxidant 0.5-1 parts, plasticizer 2-5 parts.

2. The high air barrier, fire resistant, air film building material of claim 1, wherein, Comprise the following components by weight: Polytetrafluoroethylene 70 parts, polyvinylidene fluoride 30 parts, red phosphorus 3 parts, graphene oxide 6 parts, silver nanoparticles 3.5 parts, chitosan 1.5 parts, nano magnesium stearate 4 parts, silane coupling agent 1.5 parts, antioxidant 0.8 parts, plasticizer 4 parts.

3. The high air barrier, fire resistant, air film building material of claim 1 or 2, wherein, The silane coupling agent is KH-560; the antioxidant is antioxidant 1010; the plasticizer is DOP.

4. A process for the production of a high air barrier fire resistant air film building material as claimed in claim 1 or 2, characterised in that, The process is as follows: Step one, dry the polytetrafluoroethylene and polyvinylidene fluoride particles in a vacuum oven at 75-85℃ for 4-5h; Step two, add graphene oxide, silver nanoparticles and nano magnesium stearate into N, N-dimethylformamide, ultrasonic treatment for 30-50min, to obtain a suspension; Step three, use chitosan to coat the red phosphorus, to obtain a coated product; Step four, put the dried polytetrafluoroethylene and polyvinylidene fluoride in step one into a reaction kettle, then add N-dimethylformamide, continuously stir at 60-70℃ until dissolved, to obtain a transparent viscous glue solution; Step five, add the suspension of step two, the coated product of step three, the silane coupling agent, the antioxidant and the plasticizer into the glue solution of step four in turn, shear at 3000-5000rpm for 1-2h, to make the components uniformly dispersed; then add the remaining chitosan, stir at 100rpm for 30-40min, to obtain a mixture A; Step six, send the mixture A to a vacuum degassing tank, remove the air bubbles rolled in during stirring under a vacuum degree of-0.1MPa, until no air bubbles escape from the surface of the slurry, to obtain a mixture B; Step seven, pass the mixture B through the knife head of a flow coater, uniformly coat on a clean release paper; then treat at 80±0.5℃ for 2-3h, at 130-150℃ for 1-2h; after complete drying, peel off, cool down and wind up, to obtain the product.

5. The method for preparing the high airtightness flame-retardant membrane building material as described in claim 4, characterized in that, In step two, the total weight of graphene oxide, silver nanoparticles and nano magnesium stearate to the weight of N, N-dimethylformamide is 1:20-30.

6. The method for preparing the high airtightness flame-retardant membrane building material as described in claim 4, characterized in that, In step three, the coating process is as follows: S1, take part of the chitosan, dissolve in 1.5% (v / v) acetic acid solution, stir until dissolved, to form a clear and viscous chitosan acetic acid solution; S2, add sodium dodecyl sulfate to deionized water, stir to dissolve; then slowly add red phosphorus, after adding, stir at 500rpm, to make the red phosphorus wet and dispersed; then high-speed shear at 10000rpm for 45-60min, to obtain a slurry A; S3, adjust the stirring speed to 500 rpm, and heat the slurry A to 50±0.5℃, then slowly drop the chitosan acetic acid solution into the slurry A, after dropping, continue to stir for 1.5-2h, so that the chitosan is combined with the red phosphorus, to obtain slurry B; S4, under the state of stirring, drop 10% (v / v) glutaraldehyde aqueous solution into the slurry B, after dropping, continue to stir for 1-1.5h, to obtain slurry C; S5, use 1 mol / L NaOH solution to adjust the pH of the slurry C to 8.5-8.7, then continue to react for 3-4h, to obtain slurry D; S6, after cooling, filtering the slurry D, collect the filter cake; after washing, drying the filter cake, obtain the coated product.

7. The method for preparing the high airtightness flame-retardant membrane building material as described in claim 6, characterized in that, In step S1, the weight of chitosan is 20% of the weight of red phosphorus; the weight ratio of chitosan to acetic acid solution is 1:6-10.

8. The method for preparing the high airtightness flame-retardant membrane building material as described in claim 6, characterized in that, In step S2, the weight ratio of red phosphorus to deionized water is 1:6-10, and the weight ratio of red phosphorus to sodium dodecyl sulfate is 200-220:

1.

9. The method for preparing the high airtightness flame-retardant membrane building material as described in claim 6, characterized in that, In step S4, the weight ratio of glutaraldehyde aqueous solution to red phosphorus is 1:5-6.

10. The method for preparing the high airtightness flame-retardant membrane building material as described in claim 4, characterized in that, In step four, the weight ratio of the total weight of polytetrafluoroethylene and polyvinylidene fluoride to N-dimethylformamide is 1:5-7.

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