Flame-retardant antistatic composite fabric and preparation method thereof

Abstract

The application relates to the technical field of protective fabrics, and particularly discloses a preparation method of a flame-retardant and anti-static composite fabric, which comprises the following steps: step (1), 2-(4-aminophenyl)-5-aminobenzimidazole, 1,4-bis(3-aminopropyl)piperazine and 1,2,3,4-cyclobutanetetracarboxylic dianhydride are added into an organic solvent, and polyamide acid solution is obtained through polycondensation reaction at 20-60 DEG C for 2-8 h; step (2), polyether amine, boron lanthanide, a flame retardant, an anti-static agent and a dehydrating agent are added into the polyamide acid solution, and the mixture is stirred and reacted at 35-70 DEG C for 8-16 h to obtain a polyimide solution; and step (3), the polyimide solution is prepared into fibers through a spinning method, and the fibers are subjected to spinning and weaving processes to obtain the flame-retardant and anti-static composite fabric; the preparation method is simple in steps, low in cost and suitable for industrialized production; and the obtained fabric has excellent flame-retardant, anti-static and mechanical properties and has a wide market prospect.

Description

Technical Field

[0001] This invention relates to the field of protective fabric technology, and more specifically, to a flame-retardant and antistatic composite fabric and its preparation method. Background Technology

[0002] In high-risk work environments such as petrochemicals, coal mining, fire rescue, and aerospace, specialized protective fabrics are core equipment for ensuring personnel safety. Their flame retardancy and antistatic properties directly determine their ability to resist risks such as fires and electrostatic explosions. In environments like petrochemical storage tank areas and underground coal mines, flammable and explosive gases or dust are often present. If workers' clothing lacks reliable flame retardancy, it can easily continue to burn and produce molten drips upon contact with high-temperature heat sources or open flames. This not only fails to prevent heat burns but may also ignite surrounding combustibles, causing secondary fires. Simultaneously, friction between the fabric and the body / equipment during personnel activities generates static electricity. If the fabric's antistatic properties are insufficient, the accumulated charge can generate static sparks when it reaches a critical value, easily igniting flammable and explosive media in the environment. Accidents such as gas explosions caused by static electricity in coal mines and solvent vapor ignition by static electricity in chemical workshops pose a fatal threat to operational safety. Therefore, the flame retardant and antistatic properties of specialized protective fabrics are essential safety guarantees in flammable and explosive environments.

[0003] Currently, CN118752871A discloses a high flame-retardant protective composite fabric and its preparation method, using modified polyimide / polyether composite aerogel as the heat insulation layer and aramid fiber felt as the substrate; through 4,4' Diaminodiphenyl ether, modified polyetheramine D 2000 and 3,4,3',4' Modified polyimide / polyether composite aerogel is generated through polymerization of diphenyl ether tetracarboxylic dianhydride as a raw material. Since aerogel is a porous and ultralight material, it has the characteristics of low density and high-efficiency heat insulation. At the same time, due to the introduction of phosphorous acid groups during the modification process, it can decompose at high temperature to produce flame-retardant gas. Therefore, the fabric prepared has good flame-retardant properties. However, this fabric cannot have both good flame-retardant and antistatic properties, and cannot meet the high-performance requirements of protective fabrics.

[0004] Based on the above statements, this invention proposes a flame-retardant and antistatic composite fabric and its preparation method. Summary of the Invention

[0005] To address the problem that existing protective fabrics cannot simultaneously possess good flame-retardant and antistatic properties, this invention provides a flame-retardant and antistatic composite fabric and its preparation method.

[0006] In a first aspect, the present invention provides a method for preparing a flame-retardant and antistatic composite fabric, employing the following technical solution: A method for preparing a flame-retardant and antistatic composite fabric includes the following steps: Step (1): 2-(4-aminophenyl)-5-aminobenzimidazole, 1,4-bis(3-aminopropyl)piperazine, and 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride are added to an organic solvent and polycondensed at 20-60℃ for 2-8 hours to obtain a polyamic acid solution. Step (2): Add polyetheramine, lanthanum boride, flame retardant, antistatic agent and dehydrating agent to the polyamic acid solution, and stir the reaction at 35-70℃ for 8-16 hours to obtain polyimide solution; Step (3): Polyimide solution is used to prepare fibers by spinning. The fibers are then spun and woven to obtain flame-retardant and antistatic composite fabric.

[0007] Preferably, in step (1), the mass ratio of 2-(4-aminophenyl)-5-aminobenzimidazole, 1,4-bis(3-aminopropyl)piperazine, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, and organic solvent is 5-16:4-12:20:40-60.

[0008] Preferably, in step (2), the mass ratio of polyamic acid solution, polyetheramine, lanthanum boride, flame retardant, antistatic agent and dehydrating agent is 100:10-20:1-5:3-7:0.1-2:1-5.

[0009] Preferably, the flame retardant is prepared by the following method: S1. Add sepiolite, KH560, and water to ethanol, mix well, adjust the pH to 3-5, and stir at a constant temperature of 30-50℃ for 4-6 hours. Filter, wash with alcohol, and dry the product to obtain modified sepiolite. S2. Add phytic acid and diaminomaleonitrile to water, heat to 60-80℃ and stir for 1-2 hours. Add modified sepiolite and N,N-dimethylformamide, adjust pH to 3-5, and continue stirring at 60-80℃ for 3-5 hours. Filter, wash and dry to obtain flame retardant.

[0010] Preferably, the mass ratio of sepiolite, KH560, water, and ethanol in S1 is 10:1-5:10-20:100; and the mass ratio of phytic acid, diaminomaleonitrile, water, modified sepiolite, and N,N-dimethylformamide in S2 is 6.6:6.5-7.5:100:10:20-40.

[0011] Preferably, the polyetheramine is at least one of polyetheramine D400, polyetheramine D600, polyetheramine D800, and polyetheramine D2000.

[0012] Preferably, the antistatic agent is octadecyltrimethylammonium bromide and / or octadecyltrimethylammonium chloride.

[0013] Preferably, the organic solvent is at least one selected from N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, N-methyl-2-pyrrolidone, γ-butyrolactone, methyl ethyl ketone, cyclohexanone, cyclopentanone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol methyl ethyl ether, ethylene glycol dimethyl ether, and dimethyl sulfoxide.

[0014] Preferably, the dehydrating agent is at least one selected from acetic anhydride, propionic anhydride, trifluoroacetic anhydride, pyridine, trimethylpyridine, dimethylpyridine, and triethylamine.

[0015] Secondly, the present invention provides a flame-retardant and antistatic composite fabric, which adopts the following technical solution: A flame-retardant and antistatic composite fabric is prepared by the above-described preparation method.

[0016] In summary, the present invention has the following beneficial effects: 1. The fabric of this invention uses polyimide (PI) as the main material. The polyimide skeleton is formed by the dehydration polymerization of 2-(4-aminophenyl)-5-aminobenzimidazole, 1,4-bis(3-aminopropyl)piperazine, and 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride. 2-(4-aminophenyl)-5-aminobenzimidazole introduces benzimidazole rings, and 1,4-bis(3-aminopropyl)piperazine introduces piperazine rings. The two work synergistically to improve the flame retardant and antistatic properties of the fabric.

[0017] 2. This invention obtains a flame retardant by loading silane containing epoxy groups onto the surface of sepiolite, followed by the formation of ammonium phosphate from phytic acid / diaminomaleonitrile. The active groups of the ammonium phosphate attack the epoxy groups, resulting in a covalent grafting reaction. The flame retardant can improve the flame retardant performance of the fabric from multiple aspects, including physical barrier, chemical flame inhibition, silicon-phosphorus-nitrogen synergy, and chemical stabilization. At the same time, the flame retardant and the high char-forming properties of polyimide itself have a synergistic effect, resulting in a higher quality char layer and a more prominent flame retardant effect on the fabric.

[0018] 3. This invention introduces polyetheramine into a polyamic acid solution. As a flexible chain, it can copolymerize with the rigid structure of PI to form a rigid-flexible block copolymer. Under specific conditions, the rigid-flexible block copolymer can aggregate in an orderly manner to form multi-level ordered building blocks, further improving the heat resistance and flame retardant properties of PI. In addition, the introduction of polyetheramine improves the hydrophilicity of PI, making it easier to form a water film on the fiber surface. In conjunction with the antistatic agent, it can ensure that the static charge on the fiber surface can be quickly leaked without accumulation, effectively improving the antistatic performance of the fabric.

[0019] 4. In this invention, lanthanum boride is introduced into the polyamic acid solution. At high temperature, it can react with the small organic molecules produced by the decomposition of PI to form a glassy borate protective layer, which isolates oxygen and heat transfer, and promotes polymer char formation, further enhancing the flame retardant properties of the fiber. Lanthanum ions can also form a coordination bond network with nitrogen and oxygen atoms in PI molecules, reducing the tendency of charge accumulation and enhancing the antistatic effect of the fiber.

[0020] 5. The preparation method of the fabric of the present invention is simple, low in cost, and suitable for industrial production. The resulting fabric has both excellent flame retardant and antistatic properties, as well as significant mechanical properties, and can be widely used in the field of protection. Detailed Implementation

[0021] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0022] Examples 1-3 provide a method for preparing a flame-retardant and antistatic composite fabric, as follows: Example 1 A method for preparing a flame-retardant and antistatic composite fabric includes the following steps: Step (1): 2-(4-aminophenyl)-5-aminobenzimidazole, 1,4-bis(3-aminopropyl)piperazine, and 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride were added to an organic solvent and subjected to a polycondensation reaction at 20°C for 8 hours to obtain a polyamic acid solution; wherein, the mass ratio of 2-(4-aminophenyl)-5-aminobenzimidazole, 1,4-bis(3-aminopropyl)piperazine, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, and organic solvent was 5:4:20:40; the organic solvent was N,N-dimethylformamide; Step (2): Add polyetheramine, lanthanum boride, flame retardant, antistatic agent and dehydrating agent to the polyamic acid solution, and stir and react at 35°C for 16 hours to obtain a polyimide solution; wherein, the mass ratio of polyamic acid solution, polyetheramine, lanthanum boride, flame retardant, antistatic agent and dehydrating agent is 100:10:1:3:0.1:1; the polyetheramine is polyetheramine D600; the antistatic agent is octadecyltrimethylammonium bromide; the dehydrating agent is acetic anhydride; The preparation method of flame retardant is as follows: S1. Add 10g sepiolite, 1g KH560 and 10g water to 100g ethanol, mix well, adjust pH to 3, stir at 30℃ for 6h, filter, wash with alcohol and dry to obtain modified sepiolite. S2. Add 6.6g phytic acid and 6.5g diaminomalenitrile to 100g water, heat to 60℃ and stir for 2h, add 10g modified sepiolite and 20g N,N-dimethylformamide, adjust pH to 3, continue stirring at 60℃ for 5h, filter, wash and dry to obtain flame retardant. Step (3): Polyimide solution is used to prepare fibers by melt spinning. The fibers are then spun and woven to obtain a plain weave fabric with a warp and weft density of 360 threads / 10cm, which is the flame-retardant and antistatic composite fabric.

[0023] Example 2 A method for preparing a flame-retardant and antistatic composite fabric includes the following steps: Step (1): 2-(4-aminophenyl)-5-aminobenzimidazole, 1,4-bis(3-aminopropyl)piperazine, and 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride were added to an organic solvent and subjected to a polycondensation reaction at 40°C for 5 hours to obtain a polyamic acid solution; wherein, the mass ratio of 2-(4-aminophenyl)-5-aminobenzimidazole, 1,4-bis(3-aminopropyl)piperazine, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, and organic solvent was 10:8:20:55; the organic solvent was cyclohexanone; Step (2): Add polyetheramine, lanthanum boride, flame retardant, antistatic agent and dehydrating agent to the polyamic acid solution, and stir at 50°C for 12 hours to obtain a polyimide solution; wherein, the mass ratio of polyamic acid solution, polyetheramine, lanthanum boride, flame retardant, antistatic agent and dehydrating agent is 100:15:3:6:1:3; the polyetheramine is polyetheramine D800; the antistatic agent is octadecyltrimethylammonium chloride; the dehydrating agent is pyridine; The preparation method of flame retardant is as follows: S1. Add 10g sepiolite, 3g KH560 and 15g water to 100g ethanol, mix well, adjust pH to 4, stir at 40℃ for 5h, filter, wash with alcohol and dry to obtain modified sepiolite. S2. Add 6.6g phytic acid and 7g diaminomalenitrile to 100g water, heat to 70℃ and stir for 1.5h, add 10g modified sepiolite and 30g N,N-dimethylformamide, adjust pH to 4.5, continue stirring at 70℃ for 3.5h, filter, wash and dry to obtain flame retardant. Step (3): Polyimide solution is used to prepare fibers by melt spinning. The fibers are then spun and woven to obtain a plain weave fabric with a warp and weft density of 360 threads / 10cm, which is the flame-retardant and antistatic composite fabric.

[0024] Example 3 A method for preparing a flame-retardant and antistatic composite fabric includes the following steps: Step (1): 2-(4-aminophenyl)-5-aminobenzimidazole, 1,4-bis(3-aminopropyl)piperazine, and 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride are added to an organic solvent and subjected to a polycondensation reaction at 60°C for 2 hours to obtain a polyamic acid solution; wherein, the mass ratio of 2-(4-aminophenyl)-5-aminobenzimidazole, 1,4-bis(3-aminopropyl)piperazine, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, and organic solvent is 16:12:20:60; the organic solvent is ethylene glycol monomethyl ether; Step (2): Add polyetheramine, lanthanum boride, flame retardant, antistatic agent and dehydrating agent to the polyamic acid solution, and stir at 70°C for 8 hours to obtain a polyimide solution; wherein, the mass ratio of polyamic acid solution, polyetheramine, lanthanum boride, flame retardant, antistatic agent and dehydrating agent is 100:20:5:7:2:5; the polyetheramine is polyetheramine D800; the antistatic agent is obtained by mixing octadecyltrimethylammonium bromide and octadecyltrimethylammonium chloride in a mass ratio of 1:1; the dehydrating agent is triethylamine; The preparation method of flame retardant is as follows: S1. Add 10g sepiolite, 5g KH560 and 20g water to 100g ethanol, mix well, adjust pH to 5, stir at 50℃ for 4h, filter, wash with alcohol and dry to obtain modified sepiolite. S2. Add 6.6g phytic acid and 7.5g diaminomalenitrile to 100g water, heat to 80℃ and stir for 1h, add 10g modified sepiolite and 40g N,N-dimethylformamide, adjust pH to 5, continue stirring at 80℃ for 3h, filter, wash and dry to obtain flame retardant. Step (3): Polyimide solution is used to prepare fibers by melt spinning. The fibers are then spun and woven to obtain a plain weave fabric with a warp and weft density of 360 threads / 10cm, which is the flame-retardant and antistatic composite fabric.

[0025] To verify the fabric obtained by the preparation method of the flame-retardant and antistatic composite fabric provided by this invention, the applicant has set up comparative examples 1-5, wherein: Comparative Example 1 Comparative Example 1 is the same as Example 1, except that 1,4-bis(3-aminopropyl)piperazine is replaced with an equal mass of 2-(4-aminophenyl)-5-aminobenzimidazole, as detailed below: A method for preparing a flame-retardant and antistatic composite fabric includes the following steps: Step (1): 2-(4-aminophenyl)-5-aminobenzimidazole and 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride are added to an organic solvent and subjected to polycondensation reaction at 20°C for 8 hours to obtain a polyamic acid solution; wherein, the mass ratio of 2-(4-aminophenyl)-5-aminobenzimidazole, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride and organic solvent is 9:20:40; the organic solvent is N,N-dimethylformamide; Step (2): Add polyetheramine, lanthanum boride, flame retardant, antistatic agent and dehydrating agent to the polyamic acid solution, and stir and react at 35°C for 16 hours to obtain a polyimide solution; wherein, the mass ratio of polyamic acid solution, polyetheramine, lanthanum boride, flame retardant, antistatic agent and dehydrating agent is 100:10:1:3:0.1:1; the polyetheramine is polyetheramine D600; the antistatic agent is octadecyltrimethylammonium bromide; the dehydrating agent is acetic anhydride; The preparation method of flame retardant is as follows: S1. Add 10g sepiolite, 1g KH560 and 10g water to 100g ethanol, mix well, adjust pH to 3, stir at 30℃ for 6h, filter, wash with alcohol and dry to obtain modified sepiolite. S2. Add 6.6g phytic acid and 6.5g diaminomalenitrile to 100g water, heat to 60℃ and stir for 2h, add 10g modified sepiolite and 20g N,N-dimethylformamide, adjust pH to 3, continue stirring at 60℃ for 5h, filter, wash and dry to obtain flame retardant. Step (3): Polyimide solution is used to prepare fibers by melt spinning. The fibers are then spun and woven to obtain a plain weave fabric with a warp and weft density of 360 threads / 10cm, which is the flame-retardant and antistatic composite fabric.

[0026] Comparative Example 2 Comparative Example 2 is the same as Example 1, except that an equal mass of 1,4-bis(3-aminopropyl)piperazine is used instead of 2-(4-aminophenyl)-5-aminobenzimidazole, as detailed below: A method for preparing a flame-retardant and antistatic composite fabric includes the following steps: Step (1): 1,4-bis(3-aminopropyl)piperazine and 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride are added to an organic solvent and subjected to a polycondensation reaction at 20°C for 8 hours to obtain a polyamic acid solution; wherein, the mass ratio of 1,4-bis(3-aminopropyl)piperazine, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride and organic solvent is 9:20:40; the organic solvent is N,N-dimethylformamide; Step (2): Add polyetheramine, lanthanum boride, flame retardant, antistatic agent and dehydrating agent to the polyamic acid solution, and stir and react at 35°C for 16 hours to obtain a polyimide solution; wherein, the mass ratio of polyamic acid solution, polyetheramine, lanthanum boride, flame retardant, antistatic agent and dehydrating agent is 100:10:1:3:0.1:1; the polyetheramine is polyetheramine D600; the antistatic agent is octadecyltrimethylammonium bromide; the dehydrating agent is acetic anhydride; The preparation method of flame retardant is as follows: S1. Add 10g sepiolite, 1g KH560 and 10g water to 100g ethanol, mix well, adjust pH to 3, stir at 30℃ for 6h, filter, wash with alcohol and dry to obtain modified sepiolite. S2. Add 6.6g phytic acid and 6.5g diaminomalenitrile to 100g water, heat to 60℃ and stir for 2h, add 10g modified sepiolite and 20g N,N-dimethylformamide, adjust pH to 3, continue stirring at 60℃ for 5h, filter, wash and dry to obtain flame retardant. Step (3): Polyimide solution is used to prepare fibers by melt spinning. The fibers are then spun and woven to obtain a plain weave fabric with a warp and weft density of 360 threads / 10cm, which is the flame-retardant and antistatic composite fabric.

[0027] Comparative Example 3 Comparative Example 3 is the same as Example 1, except that the flame retardant is phytic acid, as detailed below: A method for preparing a flame-retardant and antistatic composite fabric includes the following steps: Step (1): 2-(4-aminophenyl)-5-aminobenzimidazole, 1,4-bis(3-aminopropyl)piperazine, and 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride were added to an organic solvent and subjected to a polycondensation reaction at 20°C for 8 hours to obtain a polyamic acid solution; wherein, the mass ratio of 2-(4-aminophenyl)-5-aminobenzimidazole, 1,4-bis(3-aminopropyl)piperazine, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, and organic solvent was 5:4:20:40; the organic solvent was N,N-dimethylformamide; Step (2): Add polyetheramine, lanthanum boride, flame retardant, antistatic agent and dehydrating agent to the polyamic acid solution, and stir and react at 35°C for 16 hours to obtain a polyimide solution; wherein, the mass ratio of polyamic acid solution, polyetheramine, lanthanum boride, flame retardant, antistatic agent and dehydrating agent is 100:10:1:3:0.1:1; the polyetheramine is polyetheramine D600; the flame retardant is phytic acid; the antistatic agent is octadecyltrimethylammonium bromide; the dehydrating agent is acetic anhydride; Step (3): Polyimide solution is used to prepare fibers by melt spinning. The fibers are then spun and woven to obtain a plain weave fabric with a warp and weft density of 360 threads / 10cm, which is the flame-retardant and antistatic composite fabric.

[0028] Comparative Example 4 Comparative Example 4 is the same as Example 1, except that polyetheramine is not added, as detailed below: A method for preparing a flame-retardant and antistatic composite fabric includes the following steps: Step (1): 2-(4-aminophenyl)-5-aminobenzimidazole, 1,4-bis(3-aminopropyl)piperazine, and 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride were added to an organic solvent and subjected to a polycondensation reaction at 20°C for 8 hours to obtain a polyamic acid solution; wherein, the mass ratio of 2-(4-aminophenyl)-5-aminobenzimidazole, 1,4-bis(3-aminopropyl)piperazine, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, and organic solvent was 5:4:20:40; the organic solvent was N,N-dimethylformamide; Step (2): Add lanthanum boride, flame retardant, antistatic agent and dehydrating agent to the polyamic acid solution, and stir the reaction at 35°C for 16 hours to obtain a polyimide solution; wherein, the mass ratio of polyamic acid solution, lanthanum boride, flame retardant, antistatic agent and dehydrating agent is 100:1:3:0.1:1; the antistatic agent is octadecyltrimethylammonium bromide; the dehydrating agent is acetic anhydride; The preparation method of flame retardant is as follows: S1. Add 10g sepiolite, 1g KH560 and 10g water to 100g ethanol, mix well, adjust pH to 3, stir at 30℃ for 6h, filter, wash with alcohol and dry to obtain modified sepiolite. S2. Add 6.6g phytic acid and 6.5g diaminomalenitrile to 100g water, heat to 60℃ and stir for 2h, add 10g modified sepiolite and 20g N,N-dimethylformamide, adjust pH to 3, continue stirring at 60℃ for 5h, filter, wash and dry to obtain flame retardant. Step (3): Polyimide solution is used to prepare fibers by melt spinning. The fibers are then spun and woven to obtain a plain weave fabric with a warp and weft density of 360 threads / 10cm, which is the flame-retardant and antistatic composite fabric.

[0029] Comparative Example 5 Comparative Example 5 is the same as Example 1, except that lanthanum boride is not added, as detailed below: A method for preparing a flame-retardant and antistatic composite fabric includes the following steps: Step (1): 2-(4-aminophenyl)-5-aminobenzimidazole, 1,4-bis(3-aminopropyl)piperazine, and 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride were added to an organic solvent and subjected to a polycondensation reaction at 20°C for 8 hours to obtain a polyamic acid solution; wherein, the mass ratio of 2-(4-aminophenyl)-5-aminobenzimidazole, 1,4-bis(3-aminopropyl)piperazine, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, and organic solvent was 5:4:20:40; the organic solvent was N,N-dimethylformamide; Step (2): Add polyetheramine, flame retardant, antistatic agent and dehydrating agent to the polyamic acid solution, and stir the reaction at 35°C for 16 hours to obtain a polyimide solution; wherein, the mass ratio of polyamic acid solution, polyetheramine, lanthanum boride, flame retardant, antistatic agent and dehydrating agent is 100:10:3:0.1:1; the polyetheramine is polyetheramine D600; the antistatic agent is octadecyltrimethylammonium bromide; the dehydrating agent is acetic anhydride; The preparation method of flame retardant is as follows: S1. Add 10g sepiolite, 1g KH560 and 10g water to 100g ethanol, mix well, adjust pH to 3, stir at 30℃ for 6h, filter, wash with alcohol and dry to obtain modified sepiolite. S2. Add 6.6g phytic acid and 6.5g diaminomalenitrile to 100g water, heat to 60℃ and stir for 2h, add 10g modified sepiolite and 20g N,N-dimethylformamide, adjust pH to 3, continue stirring at 60℃ for 5h, filter, wash and dry to obtain flame retardant. Step (3): Polyimide solution is used to prepare fibers by melt spinning. The fibers are then spun and woven to obtain a plain weave fabric with a warp and weft density of 360 threads / 10cm, which is the flame-retardant and antistatic composite fabric.

[0030] Performance testing The performance of the flame-retardant and antistatic composite fabrics in Examples 1-3 and Comparative Examples 1-5 of the present invention was tested respectively, and the following results are shown in Table 1: The tensile breaking properties of flame-retardant and antistatic composite fabrics were tested according to GB / T 3923-1997 "Determination of tensile properties, breaking strength and elongation at break of fabrics - strip method". The flame retardant properties of flame-retardant and antistatic composite fabrics were tested in accordance with GB / T 5454-1997 "Test for Burning Performance of Textiles - Oxygen Index Method" and GB / T 5455-1997 "Test for Burning Performance of Textiles - Vertical Method". The antistatic performance of flame-retardant and antistatic composite fabrics was tested in accordance with GB / T 12703.2-2009 "Textiles - Electrostatic Test Methods - Part 2: Surface Charge Density".

[0031] Table 1: As shown in Table 1 above, the overall performance of the flame-retardant and antistatic composite fabrics in Examples 1-3 of the present invention is far superior to that in Comparative Examples 1-5. They have a higher limiting oxygen index, a vertical flammability rating of V-0, greater tensile breaking strength, and lower surface charge density. The flame-retardant and antistatic composite fabrics in Examples 1-3 have significant flame-retardant properties and excellent antistatic properties, and have broad application prospects in the field of protection.

[0032] Comparing Example 1 with Comparative Examples 1 and 2, it can be seen that the combination of 2-(4-aminophenyl)-5-aminobenzimidazole and 1,4-bis(3-aminopropyl)piperazine can achieve a 1+1 greater than 2 effect, which greatly improves the flame retardant properties, antistatic properties and tensile properties of the fabric.

[0033] Comparing Example 1 and Comparative Example 3, it can be seen that the flame retardant of the present invention is obtained by chemical bonding of sepiolite, phytic acid and diaminomaleic acid, which helps to improve the flame retardant performance of the fabric.

[0034] Comparing Example 1 with Comparative Examples 4 and 5, it can be seen that the present invention introduces polyetheramine and lanthanum boride into the polyamic acid solution, which not only enhances the flame retardant properties of the fabric, but also improves the antistatic properties of the fabric, effectively addressing the problem that existing protective fabrics cannot simultaneously possess good flame retardant and antistatic properties.

[0035] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention. Furthermore, various different embodiments of the present invention can be arbitrarily combined, as long as they do not violate the spirit of the present invention, they should also be considered as the content disclosed by the present invention.

Claims

1. A method for preparing a flame-retardant and antistatic composite fabric, characterized in that, Includes the following steps: Step (1): 2-(4-aminophenyl)-5-aminobenzimidazole, 1,4-bis(3-aminopropyl)piperazine, and 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride are added to an organic solvent and polycondensed at 20-60℃ for 2-8 hours to obtain a polyamic acid solution. Step (2): Add polyetheramine, lanthanum boride, flame retardant, antistatic agent and dehydrating agent to the polyamic acid solution, and stir the reaction at 35-70℃ for 8-16 hours to obtain polyimide solution; Step (3): Polyimide solution is used to prepare fibers by spinning. The fibers are then spun and woven to obtain flame-retardant and antistatic composite fabric.

2. The method for preparing the flame-retardant and antistatic composite fabric according to claim 1, characterized in that, In step (1), the mass ratio of 2-(4-aminophenyl)-5-aminobenzimidazole, 1,4-bis(3-aminopropyl)piperazine, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, and organic solvent is 5-16:4-12:20:40-60.

3. The method for preparing the flame-retardant and antistatic composite fabric according to claim 1, characterized in that, In step (2), the mass ratio of polyamic acid solution, polyetheramine, lanthanum boride, flame retardant, antistatic agent and dehydrating agent is 100:10-20:1-5:3-7:0.1-2:1-5.

4. The method for preparing the flame-retardant and antistatic composite fabric according to claim 1, characterized in that, The preparation method of the flame retardant is as follows: S1. Add sepiolite, KH560, and water to ethanol, mix well, adjust the pH to 3-5, and stir at a constant temperature of 30-50℃ for 4-6 hours. Filter, wash with alcohol, and dry the product to obtain modified sepiolite. S2. Add phytic acid and diaminomaleonitrile to water, heat to 60-80℃ and stir for 1-2 hours. Add modified sepiolite and N,N-dimethylformamide, adjust pH to 3-5, and continue stirring at 60-80℃ for 3-5 hours. Filter, wash and dry to obtain flame retardant.

5. The method for preparing the flame-retardant and antistatic composite fabric according to claim 4, characterized in that, The mass ratio of sepiolite, KH560, water, and ethanol in S1 is 10:1-5:10-20:100; the mass ratio of phytic acid, diaminomaleonitrile, water, modified sepiolite, and N,N-dimethylformamide in S2 is 6.6:6.5-7.5:100:10:20-40.

6. The method for preparing the flame-retardant and antistatic composite fabric according to claim 1, characterized in that, The polyetheramine is at least one of polyetheramine D400, polyetheramine D600, polyetheramine D800, and polyetheramine D2000.

7. The method for preparing the flame-retardant and antistatic composite fabric according to claim 1, characterized in that, The antistatic agent is octadecyltrimethylammonium bromide and / or octadecyltrimethylammonium chloride.

8. The method for preparing the flame-retardant and antistatic composite fabric according to claim 1, characterized in that, The organic solvent is at least one of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, N-methyl-2-pyrrolidone, γ-butyrolactone, methyl ethyl ketone, cyclohexanone, cyclopentanone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol methyl ethyl ether, ethylene glycol dimethyl ether, and dimethyl sulfoxide.

9. The method for preparing the flame-retardant and antistatic composite fabric according to claim 1, characterized in that, The dehydrating agent is at least one of acetic anhydride, propionic anhydride, trifluoroacetic anhydride, pyridine, trimethylpyridine, dimethylpyridine, and triethylamine.

10. A flame-retardant and antistatic composite fabric is prepared by the preparation method described in any one of claims 1-9.

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