Aircraft cabin fire-retardant multilayer composite fabric and preparation method thereof

Abstract

The application relates to the technical field of layered composite fabrics, and discloses an aviation cabin use flame-retardant multilayer composite fabric and a preparation method thereof. The preparation method comprises the following steps: blending acrylic fibers and polyamide fibers, weaving to form a blended single-layer fabric, and then performing pretreatment, impregnating a flame-retardant finishing solution and a flame-retardant modified sepiolite mixed solution to respectively obtain an outer-layer fabric and an inner-layer fabric, and the aviation cabin use flame-retardant multilayer composite fabric is obtained after compounding. The fabric has excellent flame-retardant performance and can be applied to interior decoration materials of aviation cabins.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of layered composite fabric, in particular to a flame-retardant multilayer composite fabric for aircraft cabin and a preparation method thereof. BACKGROUND

[0002] With the continuous growth of the aviation transportation industry, the amount of aircraft interior materials also presents a synchronous growth trend. Among them, the passenger cabin seat cover as a typical interior material, once combustion occurs in the closed and limited cabin space, it is easy to cause serious personnel casualties and major economic losses. Therefore, it is crucial to implement effective flame retardant treatment on the passenger cabin seat cover of civil aircraft. Based on this, developing efficient new fabric flame retardant technology has become the most promising way to solve the above problems.

[0003] The prior art such as Chinese patent application CN101349006A discloses a preparation method of a nano-anion automobile interior fabric. After mixing, ultrasonic dispersion treatment of deionized water, nano-anion powder, dispersing agent and coupling agent, a nano-anion finishing agent is obtained. After diluting the nano-anion finishing agent, a post-finishing nano-anion automobile interior fabric is prepared by using the dip-nip-dry process, which has vibration resistance stability, friction resistance, and can also release air negative ions, but the flame retardant performance of the fabric needs to be improved. SUMMARY

[0004] The purpose of the present application is to overcome the shortcomings of the prior art, provide a flame-retardant multilayer composite fabric for aircraft cabin and a preparation method thereof. The multilayer composite fabric has excellent flame retardant performance and can be applied to the interior materials of aircraft cabin.

[0005] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0006] A preparation method of a flame-retardant multilayer composite fabric for aircraft cabin, the preparation method comprising the following steps:

[0007] Step (1), blending acrylic fiber and polyamide fiber to obtain blended yarn, using the blended yarn as warp and weft, weaving to obtain a single-layer fabric;

[0008] Pretreating the single-layer fabric to obtain a pretreated single-layer fabric;

[0009] Immersion of the pretreated single-layer fabric in a flame-retardant finishing liquid, after immersion, taking out, light irradiation reaction, after reaction, extraction, washing, drying to obtain a flame-retardant modified single-layer fabric;

[0010] Step (2), immersion of the flame-retardant modified single-layer fabric in a flame-retardant modified sepiolite mixed solution, reaction, after reaction, taking out, washing, drying to obtain an outer layer fabric and an inner layer fabric respectively;

[0011] Step (3), the outer layer fabric and the inner layer fabric are attached, stacked and aligned, and the outer layer fabric and the inner layer fabric are stitched by using aramid sewing thread through a multi-layer fabric quilting machine, to obtain the aviation cabin use flame-retardant multi-layer composite fabric.

[0012] Preferably, in the step (1), the mass ratio of the acrylic fiber and the polyamide fiber is 50-60:40-50; the yarn count of the blended yarn is 40-60S; the gram weight of the single layer fabric is 140-160g / m 2 .

[0013] Preferably, in the step (1), the pretreatment operation includes: placing the single layer fabric in a 20wt% ethanol aqueous solution, with a bath ratio of 1:20-30, and pretreating at a temperature of 50-60℃ for 2-2.5h; after the treatment is completed, the single layer fabric is taken out, washed with water, and dried at a temperature of 50-60℃ for 24h, to obtain the pretreated single layer fabric.

[0014] Preferably, in the step (1), the bath ratio of the pretreated single layer fabric and the flame-retardant finishing liquid is 1:15-20; the immersion condition is: immersing at a temperature of 40-50℃ for 2-3h; the light irradiation reaction condition is: light irradiation reaction under the condition of a wavelength of 365nm ultraviolet light and a light irradiation distance of 15cm for 20-25min.

[0015] Preferably, in the step (1), the flame-retardant finishing liquid is prepared by the following steps:

[0016] S11, dissolving hydroxyethyl methacrylate and tetrahydrofuran, adding triethylamine and stirring uniformly, adding a tetrahydrofuran solution of hexachlorocyclotriphosphazene dropwise, reacting, purifying after the reaction is completed, drying, and obtaining modified cyclotriphosphazene;

[0017] S12, mixing the modified cyclotriphosphazene, glycidyl methacrylate, acetone and photoinitiator to obtain the flame-retardant finishing liquid.

[0018] Preferably, in the step (1), when the flame-retardant finishing liquid is prepared, in S11, the molar ratio of hydroxyethyl methacrylate, triethylamine and hexachlorocyclotriphosphazene is 8-9:8-9:1; the tetrahydrofuran solution of hexachlorocyclotriphosphazene is prepared by mixing hexachlorocyclotriphosphazene and tetrahydrofuran at a mass ratio of 1:10; and the reaction condition is: reacting at a temperature of 60-65℃ for 22-24h.

[0019] Preferably, in the step (1), when the flame-retardant finishing liquid is prepared, in S11, the purification operation includes: filtering, taking the filtrate, removing the solvent tetrahydrofuran by rotary evaporation, obtaining the reaction crude product, extracting with ethyl acetate and water, taking the organic phase, and removing the solvent ethyl acetate by rotary evaporation.

[0020] Preferably, in the preparation of the flame-retardant finishing solution in step (1), in S12, the mass ratio of modified cyclotriphosphazene, glycidyl methacrylate, acetone and photoinitiator is 8-12:8-12:80:2-2.5.

[0021] Preferably, in step (2), the bath ratio of the flame-retardant modified single-layer fabric to the flame-retardant modified sepiolite mixed solution is 1:15-20, and the reaction conditions are as follows: reaction at 80-85℃ for 2-2.5h.

[0022] Preferably, in step (2), the flame-retardant modified sepiolite mixed solution is prepared by the following steps:

[0023] S21, melamine and N,N-dimethylformamide are mixed and dissolved, the N,N-dimethylformamide solution of spirophosphoryl chloride is added dropwise, after the dropwise addition is completed, triethylamine is added, and then reaction, after the reaction is completed, suction filtration, washing and drying are performed to obtain a flame retardant;

[0024] S22, acidified sepiolite, flame retardant and toluene are mixed and ultrasonically dispersed, then reaction, after the reaction is completed, suction filtration, washing and drying are performed to obtain a flame-retardant modified sepiolite;

[0025] S23, the flame-retardant modified sepiolite is mixed with water to obtain a flame-retardant modified sepiolite mixed solution.

[0026] Preferably, in the preparation of the flame-retardant modified sepiolite mixed solution in step (2), in S21, the molar ratio of melamine, spirophosphoryl chloride and triethylamine is 1-1.1:1:1, the N,N-dimethylformamide solution of spirophosphoryl chloride is prepared by mixing spirophosphoryl chloride and N,N-dimethylformamide at a mass ratio of 1:10, the dropwise addition time of the N,N-dimethylformamide solution of spirophosphoryl chloride is 10-15min, and the reaction conditions are as follows: stirring reaction at 155-160℃ for 3-4h.

[0027] Preferably, in the preparation of the flame-retardant modified sepiolite mixed solution in step (2), the acidified sepiolite in S22 is prepared by the following steps: placing sepiolite in 2mol / L HCl aqueous solution at a solid-liquid ratio of 1:7, acidifying at room temperature for 12-15h, after the acidification is completed, filtering, taking the filter cake, washing with water, and drying at 50-60℃ for 24h to obtain acidified sepiolite.

[0028] Preferably, in the preparation of the flame-retardant modified sepiolite mixed solution in step (2), in S22, the mass ratio of acidified sepiolite, flame retardant and toluene is 1:0.6-0.8:80-100, and the reaction conditions are as follows: reaction in a nitrogen atmosphere at 80℃ for 10-12h.

[0029] Preferably, in the preparation of the flame-retardant modified sepiolite mixed solution in the step (2), the mass ratio of the flame-retardant modified sepiolite to water is 0.8-1:40 in S23.

[0030] Preferably, the flame-retardant multilayer composite fabric is prepared by the method for preparing the flame-retardant multilayer composite fabric for an aircraft cabin.

[0031] Compared with the prior art, the present application has the following beneficial effects:

[0032] 1、The present application is made of acrylic fiber and polyamide fiber blended yarn, and then woven into fabric, wherein the acrylic fiber has excellent comfort, and the polyamide fiber has good wear resistance, and the blended yarn can be made into a blended fabric with excellent use performance and comfort.

[0033] 2、The present application improves the flame-retardant performance of the blended single-layer fabric by nucleophilic substitution reaction of hydroxyethyl methacrylate and hexachlorocyclotriphosphazene to prepare etherified modified cyclotriphosphazene with methacrylate functional groups, mixing with glycidyl methacrylate, acetone and photoinitiator to prepare a flame-retardant finishing solution, which can initiate free radical polymerization by light to graft substances with carbon-carbon double bonds on the surface of the fabric.

[0034] The modified cyclotriphosphazene, as a flame retardant, has both phosphorus and nitrogen elements, excellent flame-retardant performance, and good heat resistance of cyclotriphosphazene functional groups, which can be grafted on the surface of the single-layer fabric made of acrylic fiber and polyamide fiber to give the fabric long-term flame-retardant performance; the glycidyl methacrylate has epoxy functional groups, which can provide active sites on the surface of the fabric for subsequent reactions.

[0035] 3、Sepiolite is a porous, chain-like structure silicate mineral with the advantages of non-combustion at high temperature, acid and alkali resistance, and good durability, and when it is used in combination with an intumescent flame-retardant system, the flame retardancy and smoke suppression of the system can be effectively improved. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 is a structural schematic diagram of the flame-retardant multilayer composite fabric for an aircraft cabin prepared in the present application;

[0037] Figure 2 is a reaction schematic diagram of the synthesis of modified cyclotriphosphazene in the present application;

[0038] Figure 3 is a reaction scheme for synthesizing the flame retardant in the present application;

[0039] Figure 4 is a limiting oxygen index column chart of examples 1-5 and comparative examples 1-2 in the performance test in the present application;

[0040] Figure 5 is a charring length column chart of examples 1-5 and comparative examples 1-2 in the performance test in the present application;

[0041] Figure 6 is a SEM image of the outer layer fabric prepared in example 5 in the present application;

[0042] Figure 7 is a real image of the outer layer fabric prepared in example 5 in the present application;

[0043] in the figure:

[0044] 1, outer layer fabric; 2, inner layer fabric. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0046] Example 1

[0047] The present embodiment discloses a preparation method of a flame-retardant multilayer composite fabric, and the preparation method comprises the following steps:

[0048] Step (1), acrylic fibers and polyamide fibers are blended at a mass ratio of 50:50 to obtain blended yarn with a yarn count of 40S in English system, and the blended yarn is used as warp and weft to weave a single-layer fabric with a grammage of 150 g / m 2 ;

[0049] The single-layer fabric is placed in a 20wt% ethanol aqueous solution with a bath ratio of 1:20, and is pretreated at a temperature of 50℃ for 2h. After the treatment, the single-layer fabric is taken out, washed with water, and dried at a temperature of 50℃ for 24h to obtain a pretreated single-layer fabric.

[0050] The pretreated single-layer fabric is immersed in the flame-retardant finishing liquid with a bath ratio of 1:20, and immersed at a temperature of 50 DEG C for 2 hours. After the immersion is completed, the single-layer fabric is taken out, and subjected to photo-irradiation in an ultraviolet light with a wavelength of 365 nm at a light irradiation distance of 15 cm for 20 minutes. After the reaction is completed, the single-layer fabric is extracted in a Soxhlet extractor containing acetone for 12 hours. After the extraction is completed, the single-layer fabric is washed with water and dried at a temperature of 50 DEG C for 24 hours to obtain a flame-retardant modified single-layer fabric;

[0051] The flame-retardant finishing liquid is prepared by the following steps:

[0052] S11, hydroxyethyl methacrylate and tetrahydrofuran are mixed and dissolved at a mass ratio of 1:10, triethylamine is added and stirred uniformly, a tetrahydrofuran solution of hexachlorocyclotriphosphazene is added dropwise at a temperature of 60 DEG C, and the reaction is carried out for 24 hours. After the reaction is completed, the mixture is filtered, the filtrate is taken, and the solvent tetrahydrofuran is removed by rotary evaporation to obtain a reaction crude product. The reaction crude product is extracted with ethyl acetate and water, the organic phase is taken, the solvent ethyl acetate is removed by rotary evaporation, and the mixture is dried at a temperature of 50-60 DEG C for 24 hours to obtain modified cyclotriphosphazene.

[0053] The molar ratio of hydroxyethyl methacrylate, triethylamine and hexachlorocyclotriphosphazene is 8:8:1. The tetrahydrofuran solution of hexachlorocyclotriphosphazene is prepared by mixing hexachlorocyclotriphosphazene and tetrahydrofuran at a mass ratio of 1:10.

[0054] S12, the modified cyclotriphosphazene, glycidyl methacrylate, acetone and photoinitiator BP are mixed at a mass ratio of 8:12:80:2 to obtain a flame-retardant finishing liquid.

[0055] Step (2), the flame-retardant modified single-layer fabric is immersed in the flame-retardant modified sepiolite mixed solution with a bath ratio of 1:20, and the reaction is carried out at a temperature of 80 DEG C for 2.5 hours. After the reaction is completed, the single-layer fabric is taken out, washed with ethanol and water, and dried at a temperature of 50 DEG C for 24 hours to obtain an outer layer fabric and an inner layer fabric, respectively.

[0056] The flame-retardant finishing liquid is prepared by the following steps:

[0057] S21, melamine and N,N-dimethylformamide are mixed at a mass ratio of 1:20 and dissolved at a temperature of 155 DEG C. A solution of spirophosphoryl chloride in N,N-dimethylformamide is added dropwise, the dropwise addition is completed in 10 minutes, triethylamine is added, and the mixture is stirred and reacted at a temperature of 155 DEG C for 4 hours. After the reaction is completed, the mixture is filtered, washed with carbon tetrachloride, and dried at a temperature of 50 DEG C for 24 hours to obtain a flame retardant.

[0058] The molar ratio of melamine, spirophosphoryl chloride and triethylamine is 1:1:1. The solution of spirophosphoryl chloride in N,N-dimethylformamide is prepared by mixing spirophosphoryl chloride and N,N-dimethylformamide at a mass ratio of 1:10.

[0059] S22, the sepiolite is placed in a 2 mol / L aqueous HCl solution, the solid-liquid ratio is 1:7, and the sepiolite is acidized at room temperature for 12 h. After acidization, filtration is performed, the filter cake is taken out, water is added for washing, and drying is performed at 50 DEG C for 24 h to obtain acidized sepiolite;

[0060] The acidized sepiolite, the flame retardant, and toluene are mixed at a mass ratio of 1:0.6:80, ultrasonic dispersion is performed for 20 min, reaction is performed at 80 DEG C in a nitrogen atmosphere for 10 h. After reaction, suction filtration is performed, the filter cake is taken out, washed with ethanol, and dried at 50 DEG C for 24 h to obtain flame-retardant modified sepiolite;

[0061] S23, the flame-retardant modified sepiolite is mixed with water at a mass ratio of 0.8:40 to obtain a flame-retardant modified sepiolite mixture;

[0062] Step (3), the outer layer fabric and the inner layer fabric are attached, and are stacked and aligned. The outer layer fabric and the inner layer fabric are sewn together by using aramid sewing thread through a multi-layer fabric quilting machine to obtain the flame-retardant multi-layer composite fabric.

[0063] Example 2

[0064] The embodiment discloses a preparation method of a flame-retardant multi-layer composite fabric, and the preparation method comprises the following steps:

[0065] Step (1), acrylic fibers and polyamide fibers are blended at a mass ratio of 50:50 to obtain blended yarn with a yarn count of 40S in English system. The blended yarn is used as warp and weft to weave a single-layer fabric with a grammage of 150 g / m 2 ;

[0066] The single-layer fabric is placed in a 20wt% aqueous ethanol solution, the bath ratio is 1:20, and pretreatment is performed at 50 DEG C for 2 h. After treatment, the single-layer fabric is taken out, washed with water, and dried at 50 DEG C for 24 h to obtain a pretreated single-layer fabric;

[0067] The pretreated single-layer fabric is immersed in a flame-retardant finishing liquid, the bath ratio is 1:20, and immersion is performed at 50 DEG C for 2 h. After immersion, the single-layer fabric is taken out, and photochemical reaction is performed under the condition of ultraviolet light with a wavelength of 365 nm and a light irradiation distance of 15 cm for 20 min. After reaction, the single-layer fabric is placed in a Soxhlet extractor containing acetone for extraction for 12 h. After extraction, the single-layer fabric is washed with water and dried at 50 DEG C for 24 h to obtain a flame-retardant modified single-layer fabric;

[0068] The flame-retardant finishing liquid is prepared by the following steps:

[0069] S11, hydroxyethyl methacrylate, tetrahydrofuran are mixed and dissolved in a mass ratio of 1:10, triethylamine is added and stirred uniformly, a tetrahydrofuran solution of hexachlorocyclotriphosphazene is added dropwise at a temperature of 63℃, and the reaction is carried out for 23h; after the reaction is completed, filtration is performed, the filtrate is taken, and the solvent tetrahydrofuran is removed by rotary evaporation to obtain a crude product of the reaction; extraction is performed with ethyl acetate and water, the organic phase is taken, and the solvent ethyl acetate is removed by rotary evaporation; the mixture is dried at a temperature of 50-60℃ for 24h to obtain modified cyclotriphosphazene;

[0070] The molar ratio of hydroxyethyl methacrylate, triethylamine and hexachlorocyclotriphosphazene is 8.3:8.3:1; the tetrahydrofuran solution of hexachlorocyclotriphosphazene is prepared by mixing hexachlorocyclotriphosphazene and tetrahydrofuran in a mass ratio of 1:10;

[0071] S12, the modified cyclotriphosphazene, glycidyl methacrylate, acetone and photoinitiator BP are mixed in a mass ratio of 9:11:80:2.3 to obtain a flame-retardant finishing liquid;

[0072] Step (2), the flame-retardant modified single-layer fabric is immersed in the flame-retardant modified sepiolite mixed solution with a bath ratio of 1:20, and the reaction is carried out at a temperature of 83℃ for 2.3h; after the reaction is completed, the fabric is taken out, washed with ethanol and water, and dried at a temperature of 50℃ for 24h to obtain the outer fabric and the inner fabric, respectively;

[0073] The flame-retardant modified sepiolite mixed solution is prepared by the following steps:

[0074] S21, melamine and N,N-dimethylformamide are mixed in a mass ratio of 1:20 and dissolved at a temperature of 155℃; a spirophosphoryl chloride solution in N,N-dimethylformamide is added dropwise, the dropping time is 10min; after the addition is completed, triethylamine is added, and the reaction is carried out at a temperature of 158℃ for 3.5h; after the reaction is completed, filtration is performed, the filter cake is washed with carbon tetrachloride, and the mixture is dried at a temperature of 50℃ for 24h to obtain a flame retardant;

[0075] The molar ratio of melamine, spirophosphoryl chloride and triethylamine is 1.05:1:1; the spirophosphoryl chloride solution in N,N-dimethylformamide is prepared by mixing spirophosphoryl chloride and N,N-dimethylformamide in a mass ratio of 1:10;

[0076] S22, the sepiolite is placed in a 2mol / L aqueous HCl solution, the solid-liquid ratio is 1:7, and the acidification is carried out at room temperature for 13h; after the acidification is completed, filtration is performed, the filter cake is taken, washed with water, and dried at a temperature of 50℃ for 24h to obtain acidified sepiolite;

[0077] The acidified sepiolite, the flame retardant, and toluene are mixed in a mass ratio of 1:0.65:90, ultrasonic dispersion is performed for 25 min, reaction is performed at 80 DEG C under a nitrogen atmosphere for 11 h, after the reaction is completed, filtration is performed, the filter cake is washed with ethanol, and drying is performed at 50 DEG C for 24 h to obtain the flame-retardant modified sepiolite;

[0078] S23, the flame-retardant modified sepiolite is mixed with water in a mass ratio of 0.85:40 to obtain a flame-retardant modified sepiolite mixture solution;

[0079] Step (3), the outer layer fabric and the inner layer fabric are laminated and aligned, the outer layer fabric and the inner layer fabric are sewn by using aramid sewing thread through a multi-layer fabric quilting machine to obtain the flame-retardant multi-layer composite fabric.

[0080] Example 3

[0081] The embodiment discloses a preparation method of a flame-retardant multi-layer composite fabric, and the preparation method comprises the following steps:

[0082] Step (1), acrylic fibers and polyamide fibers are blended in a mass ratio of 50:50 to obtain blended yarn with a yarn count of 40S in English system, the blended yarn is used as warp and weft, and weaving is performed to obtain a single-layer fabric with a grammage of 150 g / m 2 ;

[0083] The single-layer fabric is placed in a 20wt% ethanol aqueous solution, a bath ratio is 1:20, and pretreatment is performed at 50 DEG C for 2 h, after the treatment is completed, the single-layer fabric is taken out, washed with water, and dried at 50 DEG C for 24 h to obtain a pretreated single-layer fabric;

[0084] The pretreated single-layer fabric is immersed in a flame-retardant finishing liquid, a bath ratio is 1:20, and immersion is performed at 50 DEG C for 2 h, after the immersion is completed, the single-layer fabric is taken out, and light irradiation is performed in an ultraviolet light with a wavelength of 365 nm at a light irradiation distance of 15 cm for 20 min, after the reaction is completed, the single-layer fabric is placed in a Soxhlet extractor containing acetone for extraction for 12 h, after the extraction is completed, the single-layer fabric is washed with water and dried at 50 DEG C for 24 h to obtain a flame-retardant modified single-layer fabric;

[0085] The flame-retardant finishing liquid is prepared by the following steps:

[0086] S11, hydroxyethyl methacrylate and tetrahydrofuran are mixed and dissolved in a mass ratio of 1:10, triethylamine is added and stirred uniformly, a tetrahydrofuran solution of hexachlorocyclotriphosphazene is added dropwise at 63 DEG C, reaction is performed for 23 h, after the reaction is completed, filtration is performed, the filtrate is taken, and the solvent tetrahydrofuran is removed by rotary evaporation to obtain a reaction crude product, extraction is performed by using ethyl acetate and water, the organic phase is taken, the solvent ethyl acetate is removed by rotary evaporation, and drying is performed at 50-60 DEG C for 24 h to obtain a modified cyclotriphosphazene;

[0087] The molar ratio of hydroxyethyl methacrylate, triethylamine and hexachlorocyclotriphosphazene is 8.5:8.5:1; the tetrahydrofuran solution of hexachlorocyclotriphosphazene is prepared by mixing hexachlorocyclotriphosphazene and tetrahydrofuran at a mass ratio of 1:10;

[0088] S12, the modified cyclotriphosphazene, glycidyl methacrylate, acetone and photoinitiator BP are mixed at a mass ratio of 10:10:80:2.3 to obtain a flame-retardant finishing liquid;

[0089] Step (2), the flame-retardant modified single-layer fabric is immersed in the flame-retardant modified sepiolite mixed solution at a bath ratio of 1:20, and reacted at a temperature of 83°C for 2.3h. After the reaction is completed, the flame-retardant modified single-layer fabric is taken out, washed with ethanol and water, and dried at a temperature of 50°C for 24h to obtain the outer layer fabric and the inner layer fabric, respectively.

[0090] The flame-retardant modified sepiolite mixed solution is prepared by the following steps:

[0091] S21, melamine and N,N-dimethylformamide are mixed at a mass ratio of 1:20, dissolved at a temperature of 155°C, and the N,N-dimethylformamide solution of spirophosphoryl chloride is added dropwise. The dropwise addition is completed in 10min, and then triethylamine is added. The reaction is stirred at a temperature of 158°C for 3.5h. After the reaction is completed, the product is filtered, washed with carbon tetrachloride, and dried at a temperature of 50°C for 24h to obtain a flame retardant.

[0092] The molar ratio of melamine, spirophosphoryl chloride and triethylamine is 1.05:1:1; the N,N-dimethylformamide solution of spirophosphoryl chloride is prepared by mixing spirophosphoryl chloride and N,N-dimethylformamide at a mass ratio of 1:10;

[0093] S22, the sepiolite is placed in a 2mol / L aqueous HCl solution at a solid-liquid ratio of 1:7, and acidified at room temperature for 13h. After the acidification is completed, the product is filtered, washed with water, and dried at a temperature of 50°C for 24h to obtain acidified sepiolite.

[0094] The acidified sepiolite, the flame retardant and toluene are mixed at a mass ratio of 1:0.7:90, ultrasonically dispersed for 25min, and reacted at a temperature of 80°C for 11h in a nitrogen atmosphere. After the reaction is completed, the product is filtered, washed with ethanol, and dried at a temperature of 50°C for 24h to obtain flame-retardant modified sepiolite.

[0095] S23, the flame-retardant modified sepiolite is mixed with water at a mass ratio of 0.9:40 to obtain a flame-retardant modified sepiolite mixed solution.

[0096] Step (3), the outer layer fabric and the inner layer fabric are laminated and aligned, and the outer layer fabric and the inner layer fabric are sewn together by using aramid sewing thread through a multi-layer fabric quilting machine to obtain a flame-retardant multi-layer composite fabric.

[0097] Embodiment 4

[0098] The embodiment discloses a preparation method of a flame-retardant multilayer composite fabric, and the preparation method comprises the following steps:

[0099] Step (1), acrylic fibers and polyamide fibers are blended at a mass ratio of 50:50 to obtain blended yarn with a yarn count of 40S in English system, the blended yarn is used as warp and weft to weave a single-layer fabric with a grammage of 150 g / m 2 ;

[0100] The single-layer fabric is pretreated in a 20wt% ethanol aqueous solution at a bath ratio of 1:20 at a temperature of 50 DEG C for 2h, and then taken out, washed with water and dried at a temperature of 50 DEG C for 24h to obtain a pretreated single-layer fabric;

[0101] The pretreated single-layer fabric is immersed in a flame-retardant finishing liquid at a bath ratio of 1:20 at a temperature of 50 DEG C for 2h, and then taken out, subjected to photochemical reaction under ultraviolet light with a wavelength of 365nm at a light distance of 15cm for 20min, and then extracted in a Soxhlet extractor containing acetone for 12h, washed with water and dried at a temperature of 50 DEG C for 24h to obtain a flame-retardant modified single-layer fabric;

[0102] The flame-retardant finishing liquid is prepared by the following steps:

[0103] S11, hydroxyethyl methacrylate and tetrahydrofuran are mixed and dissolved at a mass ratio of 1:10, triethylamine is added and stirred uniformly, a tetrahydrofuran solution of hexachlorocyclotriphosphazene is added dropwise at a temperature of 63 DEG C, reaction is carried out for 23h, then filtration is carried out, the filtrate is taken, the solvent tetrahydrofuran is removed by rotary evaporation, reaction crude product is obtained, extraction is carried out with ethyl acetate and water, the organic phase is taken, the solvent ethyl acetate is removed by rotary evaporation, and drying is carried out at a temperature of 50-60 DEG C for 24h to obtain modified cyclotriphosphazene;

[0104] The molar ratio of hydroxyethyl methacrylate, triethylamine and hexachlorocyclotriphosphazene is 8.8:8.8:1, and the tetrahydrofuran solution of hexachlorocyclotriphosphazene is prepared by mixing hexachlorocyclotriphosphazene and tetrahydrofuran at a mass ratio of 1:10;

[0105] S12, the modified cyclotriphosphazene, glycidyl methacrylate, acetone and photoinitiator BP are mixed at a mass ratio of 11:9:80:2.3 to obtain a flame-retardant finishing liquid;

[0106] Step (2), the flame-retardant modified single-layer fabric is immersed in the flame-retardant modified sepiolite mixed solution with a bath ratio of 1:20, and is reacted at a temperature of 83 DEG C for 2.3 hours; after the reaction is completed, the flame-retardant modified single-layer fabric is taken out, washed with ethanol and water, and dried at a temperature of 50 DEG C for 24 hours to obtain the outer-layer fabric and the inner-layer fabric, respectively;

[0107] The flame-retardant modified sepiolite mixed solution is prepared by the following steps:

[0108] S21, melamine and N,N-dimethylformamide are mixed in a mass ratio of 1:20, and are dissolved at a temperature of 155 DEG C; an N,N-dimethylformamide solution of spirophosphoryl chloride is added dropwise, the dropwise adding time is 10 minutes; after the dropwise adding is completed, triethylamine is added, and stirring is carried out at a temperature of 158 DEG C for 3.5 hours; after the reaction is completed, the flame retardant is obtained by filtration, washing with carbon tetrachloride, and drying at a temperature of 50 DEG C for 24 hours;

[0109] The molar ratio of melamine, spirophosphoryl chloride and triethylamine is 1.05:1:1; the N,N-dimethylformamide solution of spirophosphoryl chloride is prepared by mixing spirophosphoryl chloride and N,N-dimethylformamide in a mass ratio of 1:10;

[0110] S22, the sepiolite is placed in a 2 mol / L aqueous HCl solution, the solid-liquid ratio is 1:7, and the sepiolite is acidified at room temperature for 13 hours; after the acidification is completed, the sepiolite is filtered, the filter cake is taken out, and the filter cake is washed with water and dried at a temperature of 50 DEG C for 24 hours to obtain the acidified sepiolite;

[0111] The acidified sepiolite, the flame retardant, and toluene are mixed in a mass ratio of 1:0.75:90, ultrasonic dispersion is carried out for 25 minutes, and reaction is carried out at a temperature of 80 DEG C in a nitrogen atmosphere for 11 hours; after the reaction is completed, the flame-retardant modified sepiolite is obtained by filtration, washing with ethanol, and drying at a temperature of 50 DEG C for 24 hours;

[0112] S23, the flame-retardant modified sepiolite is mixed with water in a mass ratio of 0.95:40 to obtain the flame-retardant modified sepiolite mixed solution;

[0113] Step (3), the outer-layer fabric and the inner-layer fabric are laminated and aligned, the outer-layer fabric and the inner-layer fabric are sewn by using aramid sewing thread through a multi-layer fabric quilting machine to obtain the flame-retardant multi-layer composite fabric.

[0114] Example 5

[0115] The embodiment discloses a preparation method of a flame-retardant multi-layer composite fabric, and the preparation method comprises the following steps:

[0116] Step (1): Blend acrylic fiber and nylon fiber at a mass ratio of 50:50 to obtain a blended yarn with a count of 40S (English system). Use the blended yarn as warp and weft yarns and weave it to obtain a weight of 150g / m². 2 Single-layer fabric;

[0117] The single-layer fabric was placed in a 20wt% ethanol aqueous solution with a liquor ratio of 1:20 and pretreated at 50℃ for 2 hours. After treatment, it was taken out, washed with water, and dried at 50℃ for 24 hours to obtain the pretreated single-layer fabric.

[0118] The pretreated single-layer fabric was immersed in a flame-retardant finishing solution with a liquor ratio of 1:20 at 50°C for 2 hours. After immersion, it was removed and irradiated with ultraviolet light at a wavelength of 365nm and a light distance of 15cm for 25 minutes. After the reaction, it was placed in a Soxhlet extractor containing acetone for 12 hours. After extraction, it was washed with water and dried at 50°C for 24 hours to obtain the flame-retardant modified single-layer fabric.

[0119] The flame-retardant finishing liquid is prepared by the following steps:

[0120] S11, such as Figure 2 As shown, hydroxyethyl methacrylate and tetrahydrofuran were mixed and dissolved in a mass ratio of 1:10. Triethylamine was added and stirred until homogeneous. A tetrahydrofuran solution of hexachlorocyclotriphosphazene was added dropwise at 65°C and the reaction was carried out for 22 hours. After the reaction was completed, the mixture was filtered, and the filtrate was collected. The solvent tetrahydrofuran was removed by rotary evaporation to obtain the crude product. The crude product was extracted with ethyl acetate and water. The organic phase was collected, and the solvent ethyl acetate was removed by rotary evaporation. The product was dried at 50-60°C for 24 hours to obtain the modified cyclotriphosphazene.

[0121] The molar ratio of hydroxyethyl methacrylate, triethylamine, and hexachlorocyclotriphosphazene is 9:9:1; the tetrahydrofuran solution of hexachlorocyclotriphosphazene is prepared by mixing hexachlorocyclotriphosphazene and tetrahydrofuran at a mass ratio of 1:10.

[0122] S12. Modified triphosphazene, glycidyl methacrylate, acetone, and photoinitiator BP are mixed in a mass ratio of 12:8:80:2.5 to obtain a flame-retardant finishing liquid.

[0123] Step (2): The flame-retardant modified single-layer fabric is immersed in a flame-retardant modified sepiolite mixture with a bath ratio of 1:20 and reacted at 85°C for 2 hours. After the reaction is completed, it is taken out, washed with ethanol and water, and dried at 50°C for 24 hours to obtain the outer and inner fabrics respectively.

[0124] The flame-retardant modified sepiolite mixture is prepared by the following steps:

[0125] S21, such asFigure 3 As shown, melamine and N,N-dimethylformamide were mixed at a mass ratio of 1:20 and dissolved at 155°C. A solution of spirocyclophosphamide in N,N-dimethylformamide was added dropwise over 15 minutes. After the addition was complete, triethylamine was added, and the mixture was stirred at 160°C for 3 hours. After the reaction was completed, the mixture was filtered, washed with carbon tetrachloride, and dried at 50°C for 24 hours to obtain the flame retardant.

[0126] The molar ratio of melamine, spirophosphoryl chloride, and triethylamine is 1.1:1:1; the N,N-dimethylformamide solution of spirophosphoryl chloride is prepared by mixing spirophosphoryl chloride and N,N-dimethylformamide at a mass ratio of 1:10.

[0127] S22. Place sepiolite in a 2 mol / L HCl aqueous solution with a solid-liquid ratio of 1:7 and acidify at room temperature for 15 h. After acidification, filter, take the filter cake, wash with water, and dry at 50℃ for 24 h to obtain acidified sepiolite.

[0128] Acidified sepiolite, flame retardant, and toluene were mixed at a mass ratio of 1:0.8:100, ultrasonically dispersed for 30 min, and reacted at 80°C for 12 h in a nitrogen atmosphere. After the reaction was completed, the mixture was filtered, the filter cake was washed with ethanol, and dried at 50°C for 24 h to obtain flame-retardant modified sepiolite.

[0129] S23. Mix flame-retardant modified sepiolite with water at a mass ratio of 1:40 to obtain a flame-retardant modified sepiolite mixture.

[0130] Step (3), as Figure 1 As shown, the outer and inner fabrics are bonded together and aligned. Then, aramid sewing thread is used to sew the outer and inner fabrics together using a multi-layer fabric quilting machine to obtain a flame-retardant multi-layer composite fabric.

[0131] Comparative Example 1

[0132] This comparative example discloses a method for preparing a multilayer composite fabric, the method comprising the following steps:

[0133] Step (1): Blend acrylic fiber and nylon fiber at a mass ratio of 50:50 to obtain a blended yarn with a count of 40S (English system). Use the blended yarn as warp and weft yarns and weave it to obtain a weight of 150g / m². 2 Single-layer fabric;

[0134] The single-layer fabric was placed in a 20wt% ethanol aqueous solution with a liquor ratio of 1:20 and pretreated at 50℃ for 2 hours. After treatment, it was taken out, washed with water, and dried at 50℃ for 24 hours to obtain the pretreated single-layer fabric.

[0135] The pretreated single-layer fabric is immersed in the flame-retardant finishing liquid with a bath ratio of 1:20, immersed at a temperature of 50 DEG C for 2 hours, taken out after the immersion is completed, and subjected to light irradiation in an ultraviolet light with a wavelength of 365 nm at a light irradiation distance of 15 cm for 20 minutes. After the reaction is completed, the flame-retardant modified single-layer fabric is obtained by extracting the fabric in a Soxhlet extractor containing acetone for 12 hours, washing with water, and drying at a temperature of 50 DEG C for 24 hours.

[0136] The flame-retardant finishing liquid is prepared by the following steps:

[0137] S11, hydroxyethyl methacrylate and tetrahydrofuran are mixed and dissolved at a mass ratio of 1:10, triethylamine is added and stirred uniformly, a tetrahydrofuran solution of hexachlorocyclotriphosphazene is added dropwise at a temperature of 60 DEG C, and the reaction is carried out for 24 hours. After the reaction is completed, the filtrate is taken, the solvent tetrahydrofuran is removed by rotary evaporation, the reaction crude product is obtained, extracted with ethyl acetate and water, the organic phase is taken, the solvent ethyl acetate is removed by rotary evaporation, and the modified cyclotriphosphazene is obtained by drying at a temperature of 50-60 DEG C for 24 hours.

[0138] The molar ratio of hydroxyethyl methacrylate, triethylamine and hexachlorocyclotriphosphazene is 8:8:1; the tetrahydrofuran solution of hexachlorocyclotriphosphazene is prepared by mixing hexachlorocyclotriphosphazene and tetrahydrofuran at a mass ratio of 1:10.

[0139] S12, the modified cyclotriphosphazene, glycidyl methacrylate, acetone and photoinitiator BP are mixed at a mass ratio of 8:12:80:2 to obtain the flame-retardant finishing liquid.

[0140] Step (2), the flame-retardant modified single-layer fabric is immersed in the sepiolite mixed solution with a bath ratio of 1:20, reacted at a temperature of 80 DEG C for 2.5 hours, taken out after the reaction is completed, washed with ethanol and water, and dried at a temperature of 50 DEG C for 24 hours to obtain the outer layer fabric and the inner layer fabric, respectively.

[0141] The sepiolite mixed solution is prepared by the following steps:

[0142] The sepiolite is placed in a 2 mol / L aqueous HCl solution at a solid-liquid ratio of 1:7, acidified at room temperature for 12 hours, filtered after the acidification is completed, the filter cake is taken, washed with water, and dried at a temperature of 50 DEG C for 24 hours to obtain the acidified sepiolite.

[0143] The acidified sepiolite and water are mixed at a mass ratio of 0.8:40 to obtain the sepiolite mixed solution.

[0144] Step (3), the outer layer fabric and the inner layer fabric are pasted and aligned, and the outer layer fabric and the inner layer fabric are sewn by using aramid sewing thread through a multi-layer fabric quilting machine to obtain the flame-retardant multi-layer composite fabric.

[0145] Comparative Example 2

[0146] The present comparative example discloses a preparation method of a multi-layer composite fabric, the preparation method comprising the following steps:

[0147] Step (1), acrylic fibers and polyamide fibers are blended at a mass ratio of 50:50 to obtain blended yarn with a yarn count of 40S in English, the blended yarn is used as warp and weft to weave to obtain a single-layer fabric with a grammage of 150 g / m 2 ;

[0148] The single-layer fabric is pretreated in a 20wt% ethanol aqueous solution at a bath ratio of 1:20 at a temperature of 50℃ for 2h, after the treatment, the single-layer fabric is taken out, washed with water and dried at a temperature of 50℃ for 24h to obtain a pretreated single-layer fabric;

[0149] The pretreated single-layer fabric is immersed in a flame-retardant finishing liquid at a bath ratio of 1:20 at a temperature of 50℃ for 2h, after the immersion, the single-layer fabric is taken out and subjected to photo-irradiation in ultraviolet light with a wavelength of 365nm at a light irradiation distance of 15cm for 20min, after the reaction, the single-layer fabric is extracted in a Soxhlet extractor containing acetone for 12h, after the extraction, the single-layer fabric is washed with water and dried at a temperature of 50℃ for 24h to obtain an outer-layer fabric and an inner-layer fabric, respectively;

[0150] The flame-retardant finishing liquid is prepared by the following steps:

[0151] S11, hydroxyethyl methacrylate and tetrahydrofuran are mixed and dissolved at a mass ratio of 1:10, triethylamine is added and stirred uniformly, a tetrahydrofuran solution of hexachlorocyclotriphosphazene is added dropwise at a temperature of 60℃, the reaction is carried out for 24h, after the reaction, the mixture is filtered, the filtrate is taken and the solvent tetrahydrofuran is removed by rotary evaporation to obtain a reaction crude product, the reaction crude product is extracted with ethyl acetate and water, the organic phase is taken, the solvent ethyl acetate is removed by rotary evaporation, and the mixture is dried at a temperature of 50-60℃ for 24h to obtain modified cyclotriphosphazene;

[0152] The molar ratio of hydroxyethyl methacrylate, triethylamine and hexachlorocyclotriphosphazene is 8:8:1, and the tetrahydrofuran solution of hexachlorocyclotriphosphazene is prepared by mixing hexachlorocyclotriphosphazene and tetrahydrofuran at a mass ratio of 1:10;

[0153] S12, modified cyclotriphosphazene, glycidyl methacrylate, acetone and photoinitiator BP are mixed at a mass ratio of 8:12:80:2 to obtain a flame-retardant finishing liquid;

[0154] Step (2), the outer-layer fabric and the inner-layer fabric are laminated and aligned, and the outer-layer fabric and the inner-layer fabric are sewn together by using aramid sewing thread through a multi-layer fabric quilting machine to obtain a flame-retardant multi-layer composite fabric.

[0155] In the above examples and comparative examples:

[0156] The fineness of sepiolite is 1800 mesh; the chemical name of spirocyclic phosphoryl chloride is 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide, CAS number: 714-87-4.

[0157] Test case

[0158] like Figure 4 and Figure 5 As shown, the flame retardant properties of the multilayer composite fabrics prepared in Examples 1-5 and Comparative Examples 1-2 were tested. Specific test results are shown in Table 1.

[0159] Table 1

[0160]

[0161] The tests for each indicator in Table 1 were conducted according to the following standards: The limiting oxygen index (LOI) test was performed according to GB / T 5454 "Determination of Burning Performance of Textiles - Determination of Oxygen Index", using an oxygen index meter to test the LIO of Examples 1-5 and Comparative Examples 1-2 before and after 50 washes; the vertical burning test was performed according to GB / T 5455 "Vertical Method for Testing Burning Performance of Textiles", measuring the afterflame time, smoldering time, and char length of Examples 1-5 and Comparative Examples 1-2 before and after 50 washes.

[0162] As can be seen from the test results in Table 1, the multilayer composite fabric prepared by this invention has excellent flame retardant properties.

[0163] This invention aims to improve the flame retardant properties of blended single-layer fabrics. It involves preparing a flame-retardant finishing liquid containing modified triphosphazene, glycidyl methacrylate, and a photoinitiator. Photo-initiated free radical polymerization grafts substances with carbon-carbon double bonds onto the fabric surface. Then, utilizing the ring-opening reaction between amino and epoxy groups, flame-retardant modified sepiolite containing active amino functional groups is chemically bonded to the surface of the flame-retardant modified single-layer fabric, further enhancing the fabric's flame-retardant and smoke-suppressing properties. Figure 6 It can be seen that the flame-retardant modified sepiolite adheres to the surface of the fibers in the modified single-layer fabric and is evenly distributed.

[0164] In Comparative Example 1, the sepiolite was not surface modified, lacking the flame retardant effect to improve the flame retardant effect of the fabric. Furthermore, the sepiolite surface could not form chemical bonds with the fabric surface and was easily detached after washing, thus affecting the flame retardant performance of the fabric. Therefore, the flame retardant performance of Comparative Example 1 was not as good as that of the Example, and the flame retardant effect decreased faster after washing compared to the Example.

[0165] The fabric in Comparative Example 2 was not impregnated with flame-retardant modified sepiolite mixture, and lacked the flame-retardant effect of sepiolite and flame retardants on the fabric. Therefore, the flame-retardant performance of Comparative Example 2 was not as good as that of the Example.

[0166] While embodiments of the application have been shown and described, it is to be understood that the application is not limited to the details of the embodiments described, since numerous changes, modifications, substitutions and variations can be made thereto without departing from the spirit and scope of the application as defined by the appended claims and their equivalents.

Claims

1. A method for preparing a flame-retardant multilayer composite fabric for an aircraft cabin, characterized by, The method comprises the following steps: Step (1), acrylonitrile fiber and polyamide fiber are blended to obtain blended yarn, the blended yarn is used as warp and weft to weave to obtain a single-layer fabric; The single-layer fabric is pretreated to obtain a pretreated single-layer fabric; The pretreated single-layer fabric is immersed in a flame-retardant finishing liquid, after immersion, it is taken out, light reaction is carried out, after reaction, extraction, washing and drying are carried out to obtain a flame-retardant modified single-layer fabric; The flame-retardant finishing liquid is prepared by the following steps: S11, hydroxyethyl methacrylate and tetrahydrofuran are mixed and dissolved, triethylamine is added and stirred uniformly, a tetrahydrofuran solution of hexachlorocyclotriphosphazene is added dropwise, reaction is carried out, after reaction, purification and drying are carried out to obtain modified cyclotriphosphazene; S12, the modified cyclotriphosphazene, glycidyl methacrylate, acetone and a photoinitiator are mixed to obtain the flame-retardant finishing liquid; Step (2), the flame-retardant modified single-layer fabric is immersed in a flame-retardant modified sepiolite mixed liquid, reaction is carried out, after reaction, it is taken out, washed and dried to obtain an outer-layer fabric and an inner-layer fabric respectively; The flame-retardant modified sepiolite mixed liquid is prepared by the following steps: S21, melamine and N,N-dimethylformamide are mixed and dissolved, a N,N-dimethylformamide solution of spirophosphoryl chloride is added dropwise, after dropwise addition, triethylamine is added, reaction is carried out, after reaction, suction filtration, washing and drying are carried out to obtain a flame retardant; S22, sepiolite is placed in a 2mol / L HCl aqueous solution, the solid-liquid ratio is 1:7, acidification is carried out at room temperature for 12-15h, after acidification, filtration is carried out, the filter cake is taken out, washed with water and dried at a temperature of 50-60℃ for 24h to obtain acidified sepiolite; the acidified sepiolite, the flame retardant and toluene are mixed and ultrasonically dispersed, reaction is carried out, after reaction, suction filtration, washing and drying are carried out to obtain flame-retardant modified sepiolite; S23, the flame-retardant modified sepiolite is mixed with water to obtain a flame-retardant modified sepiolite mixed liquid; Step (3), the outer-layer fabric and the inner-layer fabric are compounded to obtain a flame-retardant multi-layer composite fabric for aviation cabin.

2. The method for preparing a flame-retardant multilayer composite fabric for aircraft cabins according to claim 1, characterized in that, In the step (1), the mass ratio of the acrylic fiber to the polyamide fiber is 50-60:40-50; the yarn count of the blended yarn is 40-60 S in English count; and the gram weight of the single-layer fabric is 140-160 g / m 2 .

3. The method for preparing a flame-retardant multilayer composite fabric for aircraft cabins according to claim 1, characterized in that, In step (1), the pretreatment operation comprises: placing the single-layer fabric in a 20wt% ethanol aqueous solution, the bath ratio is 1:20-30, pretreatment is carried out at a temperature of 50-60℃ for 2-2.5h, after treatment, it is taken out, washed with water and dried at a temperature of 50-60℃ for 24h to obtain the pretreated single-layer fabric.

4. The method for preparing a flame-retardant multilayer composite fabric for aircraft cabins according to claim 1, characterized in that, In step (1), the bath ratio of the pretreated single-layer fabric to the flame-retardant finishing liquid is 1:15-20; the immersion condition is: immersion at a temperature of 40-50℃ for 2-3h; the light reaction condition is: light reaction in a wavelength of 365nm ultraviolet light, the light distance is 15cm, and the light reaction time is 20-25min.

5. The method for preparing a flame-retardant multilayer composite fabric for aircraft cabins according to claim 1, characterized in that, In step (1), when the flame-retardant finishing liquid is prepared: In S11, the molar ratio of hydroxyethyl methacrylate, triethylamine and hexachlorocyclotriphosphazene is 8-9:8-9:1; the tetrahydrofuran solution of hexachlorocyclotriphosphazene is prepared by mixing hexachlorocyclotriphosphazene and tetrahydrofuran at a mass ratio of 1:10; the reaction condition is: reaction at a temperature of 60-65℃ for 22-24h; In S12, the mass ratio of modified cyclotriphosphazene, glycidyl methacrylate, acetone and photoinitiator is 8-12:8-12:80:2-2.

5.

6. The method for preparing a flame-retardant multilayer composite fabric for aircraft cabins according to claim 1, characterized in that, In the step (2), the bath ratio of the flame-retardant modified single-layer fabric and the flame-retardant modified sepiolite mixed solution is 1:15-20, and the reaction condition is that the reaction is carried out at 80-85℃ for 2-2.5h.

7. The method for preparing a flame-retardant multilayer composite fabric for aircraft cabins according to claim 1, characterized in that, In the step (2), when the flame-retardant modified sepiolite mixed solution is prepared: In S21, the molar ratio of melamine, spirocyclic phosphorus oxychloride and triethylamine is 1-1.1:1:1, the N,N-dimethylformamide solution of spirocyclic phosphorus oxychloride is prepared by mixing spirocyclic phosphorus oxychloride and N,N-dimethylformamide at a mass ratio of 1:10, the dropping time of the N,N-dimethylformamide solution of spirocyclic phosphorus oxychloride is 10-15min, and the reaction condition is that the reaction is carried out at 155-160℃ for 3-4h under stirring; In S22, the mass ratio of acidified sepiolite, flame retardant and toluene is 1:0.6-0.8:80-100, and the reaction condition is that the reaction is carried out at 80℃ for 10-12h in a nitrogen atmosphere; In S23, the mass ratio of the flame-retardant modified sepiolite and water is 0.8-1:

40.

8. An aviation cabin flame-retardant multilayer composite fabric prepared by the preparation method of the aviation cabin flame-retardant multilayer composite fabric according to any one of claims 1-7.

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