Flame-retardant multi-layer composite fabric for aircraft cabin and preparation method of flame-retardant multi-layer composite fabric

Abstract

The invention relates to the technical field of layered composite fabrics, and discloses a flame-retardant multi-layer composite fabric for an aircraft cabin and a preparation method of the flame-retardant multi-layer composite fabric. The preparation method comprises the steps that acrylic fibers and polyamide fibers are blended and woven to form a blended single-layer fabric, then the blended single-layer fabric is pretreated, soaked in flame-retardant finishing liquid and soaked in flame-retardant modified sepiolite mixed liquid, the outer-layer fabric and the inner-layer fabric are obtained respectively, and the flame-retardant multi-layer composite fabric for the aviation cabin is obtained after compounding. The fabric has excellent flame retardant property and can be applied to interior materials of aviation cabins.

Description

Technical Field

[0001] This invention relates to the field of layered composite fabric technology, specifically to a flame-retardant multilayer composite fabric for aircraft cabins and its preparation method. Background Technology

[0002] With the continued growth of the air transport industry, the usage of aircraft interior materials has also increased accordingly. Among these, passenger seat covers, as a typical interior material, can easily lead to serious casualties and significant economic losses if they ignite in the confined space of a passenger cabin. Therefore, effective flame-retardant treatment of civil aircraft passenger seat covers is crucial. Based on this, developing efficient new flame-retardant fabric technologies has become the most promising approach to solving these problems.

[0003] Existing technologies, such as Chinese patent application CN101349006A, disclose a method for preparing nano-negative ion automotive interior fabric. The method involves mixing deionized water, nano-negative ion powder, dispersant, and coupling agent, followed by ultrasonic dispersion treatment to obtain a nano-negative ion finishing agent. After diluting the nano-negative ion finishing agent, an impregnation-pad-drying process is used to obtain a finished nano-negative ion automotive interior fabric. This fabric has vibration resistance, abrasion resistance, and can release negative air ions, but its flame retardant properties need to be improved. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a flame-retardant multilayer composite fabric for aircraft cabins and its preparation method. This multilayer composite fabric has excellent flame-retardant properties and can be applied to the interior materials of aircraft cabins.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for preparing a flame-retardant multilayer composite fabric for aircraft cabins, the method comprising the following steps: Step (1): Blend acrylic fiber and nylon fiber to obtain blended yarn. Use the blended yarn as warp and weft yarns and weave it to obtain a single-layer fabric. The single-layer fabric is pre-treated to obtain the pre-treated single-layer fabric. The pretreated single-layer fabric is immersed in a flame-retardant finishing solution. After immersion, it is taken out and subjected to light reaction. After the reaction is completed, it is extracted, washed, and dried to obtain a flame-retardant modified single-layer fabric. Step (2): Immerse the flame-retardant modified single-layer fabric in a flame-retardant modified sepiolite mixture and react. After the reaction is complete, take it out, wash it, and dry it to obtain the outer fabric and the inner fabric respectively. Step (3): Adhere the outer fabric to the inner fabric, align the layers, and sew the outer fabric to the inner fabric using aramid sewing thread through a multi-layer fabric quilting machine to obtain a flame-retardant multi-layer composite fabric for aircraft cabins.

[0006] Preferably, in step (1): the mass ratio of acrylic fiber to nylon fiber is 50-60:40-50; the yarn count of the blended yarn is 40-60S (English count); and the weight of the single-layer fabric is 140-160 g / m². 2 .

[0007] Preferably, in 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, pretreating it at 50-60℃ for 2-2.5h, taking it out after treatment, washing it with water, and drying it at 50-60℃ for 24h to obtain the pretreated single-layer fabric.

[0008] Preferably, in step (1): the ratio of the pretreated single-layer fabric to the flame-retardant finishing liquid is 1:15-20; the immersion conditions are: immersion at 40-50℃ for 2-3 hours; the light reaction conditions are: light reaction at 365nm ultraviolet light and a light distance of 15cm for 20-25 minutes.

[0009] Preferably, in step (1), 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 evenly, and a tetrahydrofuran solution of hexachlorocyclotriphosphazene is added dropwise. After the reaction is completed, the mixture is purified and dried to obtain modified cyclotriphosphazene. S12. Modified triphosphazene, glycidyl methacrylate, acetone, and photoinitiator are mixed to obtain a flame-retardant finishing liquid.

[0010] Preferably, in step (1), when preparing the flame-retardant finishing liquid, the molar ratio of hydroxyethyl methacrylate, triethylamine, and hexachlorocyclotriphosphazene in S11 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 conditions are: reacting at 60-65℃ for 22-24h.

[0011] Preferably, in step (1), when preparing the flame retardant finishing liquid, the purification operation in S11 includes: filtration, taking the filtrate, removing the solvent tetrahydrofuran by rotary evaporation to obtain the crude reaction product, extracting with ethyl acetate and water, taking the organic phase, and removing the solvent ethyl acetate by rotary evaporation.

[0012] Preferably, in step (1), when preparing the flame-retardant finishing liquid, the mass ratio of modified triphosphazene, glycidyl methacrylate, acetone, and photoinitiator in S12 is 8-12:8-12:80:2-2.5.

[0013] Preferably, in step (2), the bath ratio of the flame-retardant modified single-layer fabric to the flame-retardant modified sepiolite mixture is 1:15-20; the reaction conditions are: reaction at 80-85℃ for 2-2.5h.

[0014] Preferably, in step (2), the flame-retardant modified sepiolite mixture is prepared by the following steps: S21. Melamine and N,N-dimethylformamide are mixed and dissolved, and a solution of spirocyclophosphamide in N,N-dimethylformamide is added dropwise. After the addition is complete, triethylamine is added and the reaction is carried out. After the reaction is completed, the mixture is filtered, washed, and dried to obtain the flame retardant. S22. Mix acidified sepiolite, flame retardant, and toluene, disperse by ultrasonication, react, filter, wash, and dry to obtain flame-retardant modified sepiolite; S23. Mix flame-retardant modified sepiolite with water to obtain a flame-retardant modified sepiolite mixture.

[0015] Preferably, in step (2), when preparing the flame-retardant modified sepiolite mixture, 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 10-15 min; the reaction conditions are: stirring and reacting at 155-160℃ for 3-4 h.

[0016] Preferably, in step (2), when preparing the flame-retardant modified sepiolite mixture, the acidified sepiolite in S22 is prepared by the following steps: placing sepiolite in a 2 mol / L HCl aqueous solution with a solid-liquid ratio of 1:7, acidifying at room temperature for 12-15 h, filtering after acidification, taking the filter cake, washing with water, and drying at 50-60℃ for 24 h to obtain acidified sepiolite.

[0017] Preferably, in step (2), when preparing the flame-retardant modified sepiolite mixture, the mass ratio of acidified sepiolite, flame retardant, and toluene in S22 is 1:0.6-0.8:80-100; the reaction conditions are: reaction in a nitrogen atmosphere at 80°C for 10-12 hours.

[0018] Preferably, in step (2), when preparing the flame-retardant modified sepiolite mixture, the mass ratio of flame-retardant modified sepiolite to water in S23 is 0.8-1:40.

[0019] Preferably, a flame-retardant multilayer composite fabric is prepared using the preparation method of the flame-retardant multilayer composite fabric for aircraft cabins as described above.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention involves blending acrylic and nylon to form yarn, which is then woven into fabric. Because acrylic offers excellent comfort and nylon has good abrasion resistance, blending the two can produce a blended fabric with excellent performance in both use and wear.

[0021] 2. In order to improve the flame retardant properties of blended single-layer fabrics, this invention prepares etherified modified cyclotriphosphazene with methacrylate functional groups by nucleophilic substitution reaction between hydroxyethyl methacrylate and hexachlorocyclotriphosphazene. The modified cyclotriphosphazene is then mixed with glycidyl methacrylate, acetone, and a photoinitiator to prepare a flame retardant finishing liquid. This liquid can be photo-initiated to initiate free radical polymerization, allowing substances with carbon-carbon double bonds to be grafted onto the fabric surface. Among them, modified triphosphazene, as a flame retardant, has both phosphorus and nitrogen elements, exhibiting excellent flame retardant properties. Furthermore, the functional groups of triphosphazene have good heat resistance. Grafting them onto the surface of acrylic and nylon fibers in single-layer fabrics can impart long-lasting flame retardant properties to the fabric. Glycidyl methacrylate has epoxy functional groups, and introducing them into the fabric surface can provide active sites for subsequent reactions.

[0022] 3. Sepiolite is a porous, layered chain-like silicate mineral with advantages such as high-temperature non-combustibility, acid and alkali resistance, and good durability. Its combination with an intumescent flame-retardant system can effectively improve the system's flame retardancy and smoke suppression properties. This invention prepares a flame retardant with a chlorine-substituted group at one end and a melamine group at the other through a nucleophilic substitution reaction of spirocyclic phosphoryl chloride and melamine. The interaction between the chlorine-substituted group and the acidified sepiolite surface allows the flame retardant to be grafted onto the sepiolite surface, forming a flame-retardant modified sepiolite with active amino functional groups. Then, utilizing the ring-opening reaction between amino and epoxy groups, the flame-retardant modified sepiolite is chemically bonded to the surface of a flame-retardant modified single-layer fabric. By introducing the inorganic flame-retardant material sepiolite, the flame-retardant and smoke-suppressing properties of the fabric are further improved. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the flame-retardant multilayer composite fabric for aircraft cabins prepared in this invention. Figure 2 This is a schematic diagram of the reaction for synthesizing modified cyclotriphosphazenes in this invention; Figure 3 This is a schematic diagram of the reaction for synthesizing the flame retardant in this invention; Figure 4 This is a bar chart showing the limiting oxygen index of Examples 1-5 and Comparative Examples 1-2 in the performance test of this invention; Figure 5 These are bar charts showing the carbonization lengths of Examples 1-5 and Comparative Examples 1-2 in the performance tests of this invention. Figure 6This is a SEM image of the outer fabric prepared in Example 5 of this invention; Figure 7 This is a photograph of the outer fabric prepared in Example 5 of this invention; In the picture: 1. Outer fabric; 2. Inner fabric. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0025] Example 1

[0026] This embodiment discloses a method for preparing a flame-retardant multilayer composite fabric, the method comprising the following steps: 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; 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. 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 20 minutes. After the reaction, it was placed in a Soxhlet extractor containing acetone for 12 hours for extraction. After extraction, it was washed with water and dried at 50°C for 24 hours to obtain the flame-retardant modified single-layer fabric. The flame-retardant finishing liquid is prepared by the following steps: S11. 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 60°C. The reaction was carried out for 24 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. 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. S12. Modified triphosphazene, glycidyl methacrylate, acetone, and photoinitiator BP are mixed in a mass ratio of 8:12:80:2 to obtain a flame-retardant finishing liquid. 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 80°C for 2.5 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 fabric and the inner fabric respectively. The flame-retardant modified sepiolite mixture is prepared by the following steps: S21. Melamine and N,N-dimethylformamide are mixed at a mass ratio of 1:20 and dissolved at 155°C. A solution of spirocyclophosphamide in N,N-dimethylformamide is added dropwise over 10 minutes. After the addition is complete, triethylamine is added and the mixture is stirred at 155°C for 4 hours. After the reaction is complete, the mixture is filtered, washed with carbon tetrachloride, and dried at 50°C for 24 hours to obtain the flame retardant. The molar ratio of melamine, spirophosphoryl chloride, and triethylamine is 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. 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 12 h. After acidification, filter, take the filter cake, wash with water, and dry at 50℃ for 24 h to obtain acidified sepiolite. Acidified sepiolite, flame retardant, and toluene were mixed at a mass ratio of 1:0.6:80, ultrasonically dispersed for 20 min, and reacted at 80°C for 10 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. S23. Mix flame-retardant modified sepiolite with water at a mass ratio of 0.8:40 to obtain a flame-retardant modified sepiolite mixture. Step (3): Adhere the outer fabric to the inner fabric, align the layers, and sew the outer fabric to the inner fabric using aramid sewing thread through a multi-layer fabric quilting machine to obtain a flame-retardant multi-layer composite fabric.

[0027] Example 2 This embodiment discloses a method for preparing a flame-retardant multilayer composite fabric, the method comprising the following steps: 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; 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. 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 20 minutes. After the reaction, it was placed in a Soxhlet extractor containing acetone for 12 hours for extraction. After extraction, it was washed with water and dried at 50°C for 24 hours to obtain the flame-retardant modified single-layer fabric. The flame-retardant finishing liquid is prepared by the following steps: S11. 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 63°C. The reaction was carried out for 23 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. 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 at a mass ratio of 1:10. S12. Modified triphosphazene, 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. 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 83°C for 2.3 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. The flame-retardant modified sepiolite mixture is prepared by the following steps: S21. Melamine and N,N-dimethylformamide are mixed at a mass ratio of 1:20 and dissolved at 155°C. A solution of spirocyclophosphamide in N,N-dimethylformamide is added dropwise over 10 minutes. After the addition is complete, triethylamine is added and the mixture is stirred at 158°C for 3.5 hours. After the reaction is complete, the mixture is filtered, washed with carbon tetrachloride, and dried at 50°C for 24 hours to obtain the flame retardant. 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. 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 13 hours. After acidification, filter, take the filter cake, wash with water, and dry at 50°C for 24 hours to obtain acidified sepiolite. Acidified sepiolite, flame retardant, and toluene were mixed at a mass ratio of 1:0.65:90, ultrasonically dispersed for 25 min, and reacted at 80°C for 11 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. S23. Mix flame-retardant modified sepiolite with water at a mass ratio of 0.85:40 to obtain a flame-retardant modified sepiolite mixture. Step (3): Adhere the outer fabric to the inner fabric, align the layers, and sew the outer fabric to the inner fabric using aramid sewing thread through a multi-layer fabric quilting machine to obtain a flame-retardant multi-layer composite fabric.

[0028] Example 3 This embodiment discloses a method for preparing a flame-retardant multilayer composite fabric, the method comprising the following steps: 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; 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. 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 20 minutes. After the reaction, it was placed in a Soxhlet extractor containing acetone for 12 hours for extraction. After extraction, it was washed with water and dried at 50°C for 24 hours to obtain the flame-retardant modified single-layer fabric. The flame-retardant finishing liquid is prepared by the following steps: S11. 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 63°C. The reaction was carried out for 23 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. 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. S12. Modified triphosphazene, glycidyl methacrylate, acetone, and photoinitiator BP are mixed in a mass ratio of 10:10:80:2.3 to obtain a flame-retardant finishing liquid. 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 83°C for 2.3 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. The flame-retardant modified sepiolite mixture is prepared by the following steps: S21. Melamine and N,N-dimethylformamide are mixed at a mass ratio of 1:20 and dissolved at 155°C. A solution of spirocyclophosphamide in N,N-dimethylformamide is added dropwise over 10 minutes. After the addition is complete, triethylamine is added and the mixture is stirred at 158°C for 3.5 hours. After the reaction is complete, the mixture is filtered, washed with carbon tetrachloride, and dried at 50°C for 24 hours to obtain the flame retardant. 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. 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 13 hours. After acidification, filter, take the filter cake, wash with water, and dry at 50°C for 24 hours to obtain acidified sepiolite. Acidified sepiolite, flame retardant, and toluene were mixed at a mass ratio of 1:0.7:90, ultrasonically dispersed for 25 min, and reacted at 80°C for 11 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. S23. Mix flame-retardant modified sepiolite with water at a mass ratio of 0.9:40 to obtain a flame-retardant modified sepiolite mixture. Step (3): Adhere the outer fabric to the inner fabric, align the layers, and sew the outer fabric to the inner fabric using aramid sewing thread through a multi-layer fabric quilting machine to obtain a flame-retardant multi-layer composite fabric.

[0029] Example 4 This embodiment discloses a method for preparing a flame-retardant multilayer composite fabric, the method comprising the following steps: 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; 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. 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 20 minutes. After the reaction, it was placed in a Soxhlet extractor containing acetone for 12 hours for extraction. After extraction, it was washed with water and dried at 50°C for 24 hours to obtain the flame-retardant modified single-layer fabric. The flame-retardant finishing liquid is prepared by the following steps: S11. 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 63°C. The reaction was carried out for 23 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. The molar ratio of hydroxyethyl methacrylate, triethylamine, and hexachlorocyclotriphosphazene is 8.8:8.8:1; the tetrahydrofuran solution of hexachlorocyclotriphosphazene is prepared by mixing hexachlorocyclotriphosphazene and tetrahydrofuran at a mass ratio of 1:10. S12. Modified triphosphazene, glycidyl methacrylate, acetone, and photoinitiator BP are mixed in a mass ratio of 11:9:80:2.3 to obtain a flame-retardant finishing liquid. 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 83°C for 2.3 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. The flame-retardant modified sepiolite mixture is prepared by the following steps: S21. Melamine and N,N-dimethylformamide are mixed at a mass ratio of 1:20 and dissolved at 155°C. A solution of spirocyclophosphamide in N,N-dimethylformamide is added dropwise over 10 minutes. After the addition is complete, triethylamine is added and the mixture is stirred at 158°C for 3.5 hours. After the reaction is complete, the mixture is filtered, washed with carbon tetrachloride, and dried at 50°C for 24 hours to obtain the flame retardant. 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. 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 13 hours. After acidification, filter, take the filter cake, wash with water, and dry at 50°C for 24 hours to obtain acidified sepiolite. Acidified sepiolite, flame retardant, and toluene were mixed at a mass ratio of 1:0.75:90, ultrasonically dispersed for 25 min, and reacted at 80°C for 11 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. S23. Mix flame-retardant modified sepiolite with water at a mass ratio of 0.95:40 to obtain a flame-retardant modified sepiolite mixture. Step (3): Adhere the outer fabric to the inner fabric, align the layers, and sew the outer fabric to the inner fabric using aramid sewing thread through a multi-layer fabric quilting machine to obtain a flame-retardant multi-layer composite fabric.

[0030] Example 5 This embodiment discloses a method for preparing a flame-retardant multilayer composite fabric, the method comprising the following steps: 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; 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. 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. The flame-retardant finishing liquid is prepared by the following steps: 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. 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. 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. 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. The flame-retardant modified sepiolite mixture is prepared by the following steps: S21, such as Figure 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. 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. 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. 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. S23. Mix flame-retardant modified sepiolite with water at a mass ratio of 1:40 to obtain a flame-retardant modified sepiolite mixture. Step (3), as Figure 1 As shown, the outer and inner fabrics are bonded together, aligned, and then sewn together using aramid sewing thread through a multi-layer fabric quilting machine to obtain a flame-retardant multi-layer composite fabric.

[0031] Comparative Example 1 This comparative example discloses a method for preparing a multilayer composite fabric, the method comprising the following steps: 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; 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. 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 20 minutes. After the reaction, it was placed in a Soxhlet extractor containing acetone for 12 hours for extraction. After extraction, it was washed with water and dried at 50°C for 24 hours to obtain the flame-retardant modified single-layer fabric. The flame-retardant finishing liquid is prepared by the following steps: S11. 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 60°C. The reaction was carried out for 24 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. 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. S12. Modified triphosphazene, glycidyl methacrylate, acetone, and photoinitiator BP are mixed in a mass ratio of 8:12:80:2 to obtain a flame-retardant finishing liquid. Step (2): The flame-retardant modified single-layer fabric is immersed in sepiolite mixture with a bath ratio of 1:20 and reacted at 80°C for 2.5 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 layer fabric and the inner layer fabric respectively. The sepiolite mixture is prepared by the following steps: Sepiolite was placed in a 2 mol / L HCl aqueous solution with a solid-liquid ratio of 1:7 and acidified at room temperature for 12 h. After acidification, the solution was filtered, the filter cake was washed with water, and dried at 50 °C for 24 h to obtain acidified sepiolite. Acidified sepiolite and water were mixed at a mass ratio of 0.8:40 to obtain a sepiolite mixture. Step (3): Adhere the outer fabric to the inner fabric, align the layers, and sew the outer fabric to the inner fabric using aramid sewing thread through a multi-layer fabric quilting machine to obtain a flame-retardant multi-layer composite fabric.

[0032] Comparative Example 2 This comparative example discloses a method for preparing a multilayer composite fabric, the method comprising the following steps: 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; 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. The pretreated single-layer fabric was immersed in flame-retardant finishing solution at a liquor ratio of 1:20 for 2 hours at 50°C. After immersion, it was removed and irradiated for 20 minutes under ultraviolet light at a wavelength of 365nm and a light distance of 15cm. After the reaction, it was extracted 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 outer and inner layers of fabric. The flame-retardant finishing liquid is prepared by the following steps: S11. 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 60°C. The reaction was carried out for 24 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. 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. S12. Modified triphosphazene, glycidyl methacrylate, acetone, and photoinitiator BP are mixed in a mass ratio of 8:12:80:2 to obtain a flame-retardant finishing liquid. Step (2): Adhere the outer fabric to the inner fabric, align the layers, and sew the outer fabric to the inner fabric using aramid sewing thread through a multi-layer fabric quilting machine to obtain a flame-retardant multi-layer composite fabric.

[0033] In the above embodiments and comparative examples: 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.

[0034] Test case 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. Table 1

[0035] 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.

[0036] As can be seen from the test results in Table 1, the multilayer composite fabric prepared by this invention has excellent flame retardant properties.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a flame-retardant multilayer composite fabric for aircraft cabins, characterized in that, Includes the following steps: Step (1): Blend acrylic fiber and nylon fiber to obtain blended yarn. Use the blended yarn as warp and weft yarns and weave it to obtain a single-layer fabric. The single-layer fabric is pre-treated to obtain the pre-treated single-layer fabric. The pretreated single-layer fabric is immersed in a flame-retardant finishing solution. After immersion, it is taken out and subjected to light reaction. After the reaction is completed, it is extracted, washed, and dried to obtain a flame-retardant modified single-layer fabric. Step (2): Immerse the flame-retardant modified single-layer fabric in a flame-retardant modified sepiolite mixture and react. After the reaction is complete, take it out, wash it, and dry it to obtain the outer fabric and the inner fabric respectively. Step (3): Combine the outer fabric with the inner fabric to obtain a flame-retardant multi-layer composite fabric for aircraft cabins.

2. The method for preparing a flame-retardant multilayer composite fabric for aircraft cabins according to claim 1, characterized in that, In step (1): the mass ratio of acrylic fiber to nylon fiber is 50-60:40-50; the yarn count of the blended yarn is 40-60S (English count); and the weight of the single-layer fabric is 140-160 g / m². 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 includes: placing the single-layer fabric in a 20wt% ethanol aqueous solution with a bath ratio of 1:20-30, pretreating it at 50-60℃ for 2-2.5h, taking it out after treatment, washing it with water, and drying it at 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 ratio of the pretreated single-layer fabric to the flame-retardant finishing liquid is 1:15-20; the immersion conditions are: immersion at 40-50℃ for 2-3 hours; the light reaction conditions are: light reaction at 365nm ultraviolet light and a light distance of 15cm for 20-25 minutes.

5. The method for preparing a flame-retardant multilayer composite fabric for aircraft cabins according to claim 1, characterized in that, In step (1), 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 evenly, and a tetrahydrofuran solution of hexachlorocyclotriphosphazene is added dropwise. After the reaction is completed, the mixture is purified and dried to obtain modified cyclotriphosphazene. S12. Modified triphosphazene, glycidyl methacrylate, acetone, and photoinitiator are mixed to obtain a flame-retardant finishing liquid.

6. The method for preparing a flame-retardant multilayer composite fabric for aircraft cabins according to claim 1, characterized in that, When preparing the flame-retardant finishing liquid in step (1): 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 conditions are: reacting at 60-65℃ for 22-24h; In S12, the mass ratio of modified triphosphazene, glycidyl methacrylate, acetone, and photoinitiator is 8-12:8-12:80:2-2.

5.

7. The method for preparing a flame-retardant multilayer composite fabric for aircraft cabins according to claim 1, characterized in that, In step (2), the bath ratio of the flame-retardant modified single-layer fabric to the flame-retardant modified sepiolite mixture is 1:15-20; the reaction conditions are: reaction at 80-85℃ for 2-2.5h.

8. The method for preparing a flame-retardant multilayer composite fabric for aircraft cabins according to claim 1, characterized in that, In step (2), the flame-retardant modified sepiolite mixture is prepared by the following steps: S21. Melamine and N,N-dimethylformamide are mixed and dissolved, and a solution of spirocyclophosphamide in N,N-dimethylformamide is added dropwise. After the addition is complete, triethylamine is added and the reaction is carried out. After the reaction is completed, the mixture is filtered, washed, and dried to obtain the flame retardant. S22. Mix acidified sepiolite, flame retardant, and toluene, disperse by ultrasonication, react, filter, wash, and dry to obtain flame-retardant modified sepiolite; S23. Mix flame-retardant modified sepiolite with water to obtain a flame-retardant modified sepiolite mixture.

9. The method for preparing a flame-retardant multilayer composite fabric for aircraft cabins according to claim 1, characterized in that, In step (2), when preparing the flame-retardant modified sepiolite mixture: 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 10-15 min; the reaction conditions are: stirring at 155-160℃ for 3-4 h. In S22: the mass ratio of acidified sepiolite, flame retardant, and toluene is 1:0.6-0.8:80-100; the reaction conditions are: reaction at 80℃ for 10-12 hours in a nitrogen atmosphere; wherein, the acidified sepiolite is prepared by the following steps: placing sepiolite in a 2 mol / L HCl aqueous solution with a solid-liquid ratio of 1:7, acidifying at room temperature for 12-15 hours, after acidification, filtering, taking the filter cake, washing with water, and drying at 50-60℃ for 24 hours to obtain acidified sepiolite; In S23, the mass ratio of flame-retardant modified sepiolite to water is 0.8-1:

40.

10. A flame-retardant multilayer composite fabric prepared by the method for preparing flame-retardant multilayer composite fabric as described in any one of claims 1-9.

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