Preparation method of polyamide 6 fabric based on amino modified cyclotriphosphazene flame retardance

Abstract

The invention belongs to the technical field of fabric flame-retardant modification, and discloses a preparation method of a chinlon 6 fabric based on amino modified cyclotriphosphazene flame retardance, which comprises the following steps: dissolving an amino modified cyclotriphosphazene flame retardant and cyanuric chloride in an organic solvent to obtain a flame-retardant solution, immersing the chinlon 6 fabric in the flame-retardant solution for immersion treatment, and drying to obtain the chinlon 6 fabric based on amino modified cyclotriphosphazene flame retardance. The polyamide 6 fabric based on amino modified cyclotriphosphazene flame retardance is prepared. The flame-retardant film can be grafted and fixed on the surface of the chinlon 6 fabric only through combination of a small amount of covalent bonds, so that an efficient and durable flame-retardant function is provided.

Description

Technical Field

[0001] The invention belongs to the technical field of flame retardant modification of fabrics and relates to a method for preparing a flame retardant nylon 6 fabric based on amino-modified cyclotriphosphazene. Background Art

[0002] Nylon 6 fiber has been widely used in many fields such as clothing, home textiles and industrial textiles due to its excellent mechanical strength, outstanding wear resistance, low density and good hygroscopicity. However, the limiting oxygen index of this fiber is only 21%, which belongs to the category of flammable fiber. In particular, since nylon 6 fiber products are often designed to be thin and light with a large specific surface area, once they burn, they burn quickly and are accompanied by severe dripping. This characteristic can easily cause or aggravate fires, thus posing a serious threat to people's lives and property safety. Therefore, it is particularly important and urgent to improve the flame retardancy and anti-drip properties of nylon 6 fabrics.

[0003] In the process of exploring flame retardant materials, hexachlorocyclotriphosphazene (HCCP) has attracted much attention due to its unique phosphorus and nitrogen alternating ring structure. Phosphorus and nitrogen elements show good flame retardant synergistic effect in this structure, which provides a possibility for improving the flame retardant properties of materials. However, hexachlorocyclotriphosphazene is highly active and shows instability during the application process, which limits its feasibility of direct use in the flame retardant modification of nylon 6 fabrics. Despite this, its research value in the field of flame retardancy cannot be ignored, and it also provides valuable ideas and directions for the development of new flame retardant materials.

[0004] For example, in the literature (Study on the flame retardancy of wool fabrics using hexa(4-aminophenoxy)cyclotriphosphazene [J]. Printing and Dyeing Auxiliary Agents, 2016(12):49-53.), hexa(4-aminophenoxy)cyclotriphosphazene, a derivative of hexachlorocyclotriphosphazene, was used for flame retardant finishing of wool fabrics by the dip-padding-drying method. Since wool fibers contain a large amount of amino groups, this property allows hexa(4-aminophenoxy)cyclotriphosphazene to bond with wool through ionic bonds. However, the content of active amino groups on nylon 6 fabrics is relatively low, making it difficult to graft a sufficient amount of flame retardant onto nylon 6 fabrics, and therefore it is impossible to effectively improve the flame retardancy and flame retardant and water washability of nylon 6 fabrics.

[0005] Therefore, it is of great significance to study a preparation method of nylon 6 fabric based on amino-modified cyclotriphosphazene flame retardant to solve the above problems. Summary of the invention

[0006] The purpose of the present invention is to solve the problems existing in the prior art and provide a method for preparing a flame-retardant nylon 6 fabric based on amino-modified cyclotriphosphazene.

[0007] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] A method for preparing a nylon 6 fabric based on amino-modified cyclotriphosphazene flame retardant, comprising dissolving an amino-modified cyclotriphosphazene flame retardant and cyanuric chloride in an organic solvent to obtain a flame retardant liquid, immersing the nylon 6 fabric in the flame retardant liquid for immersion treatment, and air-drying or baking at room temperature to obtain the nylon 6 fabric based on amino-modified cyclotriphosphazene flame retardant;

[0009] The chemical formula of amino-modified cyclotriphosphazene flame retardant is .

[0010] As the preferred technical solution:

[0011] According to the method for preparing a nylon 6 fabric based on amino-modified cyclotriphosphazene flame retardant, the unmodified nylon 6 fabric has a damaged length of 30 cm, a limiting oxygen index of 20.1%, and molten droplets exist and ignite the absorbent cotton; the nylon 6 fabric based on amino-modified cyclotriphosphazene flame retardant has a limiting oxygen index of not less than 29.8%, a damaged length of not more than 10.5 cm, no molten droplets are generated, and can still pass the vertical combustion test after 50 washes, and the damaged length is not more than 14.6 cm, and no molten droplets are generated, which indicates that the nylon 6 fabric based on amino-modified cyclotriphosphazene flame retardant prepared by the present invention has good flame retardant properties and water washability.

[0012] As described above, a method for preparing a nylon 6 fabric based on amino-modified cyclotriphosphazene flame retardant is provided, wherein the preparation method of the amino-modified cyclotriphosphazene flame retardant is as follows: hexachlorocyclotriphosphazene and ethylenediamine are dissolved in chloroform, triethylamine is used as an acid binding agent, the mixture is reacted at 20-30°C for 4-5h, and then the amino-modified cyclotriphosphazene flame retardant is obtained by vacuum distillation.

[0013] In the preparation method of the flame-retardant nylon 6 fabric based on amino-modified cyclotriphosphazene as described above, the molar ratio of hexachlorocyclotriphosphazene to ethylenediamine is 1:6~6.6. Theoretically, each mole of hexachlorocyclotriphosphazene undergoes a nucleophilic substitution reaction with six moles of ethylenediamine, and the molar ratio of hexachlorocyclotriphosphazene to triethylamine is 1:6~7.

[0014] In the method for preparing the flame-retardant nylon 6 fabric based on amino-modified cyclotriphosphazene as described above, the temperature of the reduced pressure distillation is 40-50° C. and the vacuum degree is 1.5-2.0 kPa.

[0015] In the method for preparing the flame-retardant nylon 6 fabric based on amino-modified cyclotriphosphazene as described above, the organic solvent is a mixture of acetone and distilled water, and the acetone accounts for 15-20% of the total volume of the organic solvent.

[0016] As described above, in the preparation method of nylon 6 fabric based on amino-modified cyclotriphosphazene flame retardant, the content of amino-modified cyclotriphosphazene flame retardant in the flame retardant liquid is 70-100 g / L, and the content of cyanuric chloride is 40-60 g / L. The higher the amount of flame retardant, the more helpful it is to improve the flame retardant properties of nylon 6 fabric, but too high will be wasteful.

[0017] In the preparation method of the amino-modified cyclotriphosphazene flame-retardant nylon 6 fabric as described above, the bath ratio of the impregnation is 1:30-40; after the impregnation, the fabric is shaken at 75-85° C. for 50-70 minutes.

[0018] The principle of the present invention is:

[0019] Hexachlorocyclotriphosphazene has high phosphorus and nitrogen contents. However, hexachlorocyclotriphosphazene is highly active and unstable during use, making it difficult to directly apply it to the flame retardant modification of nylon 6 fabric. In addition, the content of active groups on the surface of nylon 6 fabric is relatively low, making it difficult to graft a sufficient amount of flame retardant molecules onto the surface of nylon 6 fabric through covalent bond grafting reactions, and the flame retardant durability needs to be further improved.

[0020] The active chlorine of hexachlorocyclotriphosphazene can undergo nucleophilic substitution reaction with the amino group of ethylenediamine, thereby preparing amino-modified cyclotriphosphazene flame retardant. On the one hand, the surface of amino-modified cyclotriphosphazene flame retardant is rich in amino groups, which can undergo nucleophilic substitution reaction with the active chlorine of cyanuric chloride, thereby generating flame-retardant polymer in situ on the surface of nylon 6 fabric; on the other hand, the excess active chlorine of cyanuric chloride can undergo nucleophilic substitution reaction with the amino group on nylon 6 fabric, and the reaction conditions are mild and the reaction efficiency is high. Therefore, the flame-retardant polymer is grafted on the surface of nylon 6 fabric through covalent bonds. Even if the content of active amino groups on nylon 6 fabric is low, cyanuric chloride and amino-modified cyclotriphosphazene flame retardant have high reaction activity, and the generated polymer is very easy to form a film (flame-retardant film) on the surface of the fabric. Therefore, the flame-retardant film can be grafted and fixed on the surface of the fabric only through a small amount of covalent bonding, thereby providing efficient and durable flame-retardant function.

[0021] In addition, the phosphate group of the amino-modified cyclotriphosphazene flame retardant can act as an acid source, the amino group of the amino-modified cyclotriphosphazene flame retardant and ethylenediamine can act as a gas source, and cyanuric chloride not only acts as a cross-linking agent, but also acts as a triazine carbonizing agent, with high carbonizing efficiency, organically constructing an intumescent flame retardant system, and having a good flame retardant effect, which can effectively improve the flame retardant properties of nylon 6 fabric; and because the carbonization of nylon 6 fabric is promoted, the droplet phenomenon is reduced.

[0022] Beneficial effects:

[0023] (1) The amino-modified cyclotriphosphazene flame retardant prepared by the present invention is rich in amino groups on its surface and can undergo nucleophilic substitution reaction with the active chlorine of cyanuric chloride, thereby generating a flame retardant polymer in situ on the surface of nylon 6 fabric; and the excess active chlorine of cyanuric chloride can undergo nucleophilic substitution reaction with the amino groups on the nylon 6 fabric, and finally the flame retardant film can be grafted and fixed on the surface of the fabric only through a small amount of covalent bonds, thereby providing a highly efficient and durable flame retardant function.

[0024] (2) The phosphate group of the amino-modified cyclotriphosphazene flame retardant prepared by the present invention can serve as an acid source, and the amino groups of the amino-modified cyclotriphosphazene flame retardant and ethylenediamine can serve as a gas source. The cyanuric chloride used not only serves as a cross-linking agent, but also serves as a triazine carbon-forming agent, which can organically construct an intumescent flame retardant system with good flame retardant effect, and can effectively improve the flame retardant properties of nylon 6 fabric. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The carbon nuclear magnetic resonance spectrum of the amino-modified cyclotriphosphazene flame retardant prepared by the present invention. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0027] The testing methods of the relevant performance indicators in the following embodiments and comparative examples are as follows:

[0028] Limiting oxygen index: GB / T 5454-1997 "Oxygen index method for textile combustion performance test" was used to measure the limiting oxygen index of the amino-modified cyclotriphosphazene flame-retardant nylon 6 fabrics prepared in the following examples and the cyclotriphosphazene flame-retardant nylon 6 fabrics prepared in the comparative examples.

[0029] Damage length and droplet performance: GB / T 5455-2014 "Determination of damage length, smoldering and afterflaming time in the vertical direction of combustion performance of textiles" was used to measure the damage length and droplet performance of the amino-modified cyclotriphosphazene flame-retardant nylon 6 fabrics prepared in the following examples and the cyclotriphosphazene flame-retardant nylon 6 fabrics prepared in the comparative examples.

[0030] Damage length and droplet performance after 50 washings: The amino-modified cyclotriphosphazene flame-retardant nylon 6 fabrics prepared in the following embodiments and the cyclotriphosphazene flame-retardant nylon 6 fabrics prepared in the comparative examples were washed 50 times with reference to AATCC 61-2013 "Accelerated test for color fastness to washing for household and commercial use" standard, and then the damage length and droplet performance of the amino-modified cyclotriphosphazene flame-retardant nylon 6 fabrics and cyclotriphosphazene flame-retardant nylon 6 fabrics after washing were tested with reference to GB / T 5455-2014 "Determination of damage length in vertical direction of burning performance of textiles - smoldering and afterflaming time" standard.

[0031] Carbon residue: The carbon residue of the fabric is the mass retention rate at 800 °C under nitrogen conditions in the thermal analysis test, with a heating rate of 10 °C / min.

[0032] Example 1

[0033] A method for preparing a flame-retardant nylon 6 fabric based on amino-modified cyclotriphosphazene, comprising the following steps:

[0034] (1) Preparation of amino-modified cyclotriphosphazene flame retardant;

[0035] Hexachlorocyclotriphosphazene and ethylenediamine are dissolved in chloroform, triethylamine is used as an acid-binding agent, the mixture is reacted at 20°C for 5 hours, and then the amino-modified cyclotriphosphazene flame retardant is prepared by vacuum distillation and ethanol washing; wherein the molar ratio of hexachlorocyclotriphosphazene to ethylenediamine is 1:6, the molar ratio of hexachlorocyclotriphosphazene to triethylamine is 1:6, and the mass ratio of chloroform to hexachlorocyclotriphosphazene is 30:1; the temperature of the vacuum distillation is 40°C, and the vacuum degree is 2kPa;

[0036] The chemical formula of the prepared amino-modified cyclotriphosphazene flame retardant is Its carbon NMR spectrum is as follows Figure 1 As shown in the figure, it can be seen that the chemical shifts at 42.0ppm and 40.1ppm are caused by the carbon elements connected to the unreacted amino group and the reactive amino group, which also shows that the amino-modified cyclotriphosphazene flame retardant is successfully synthesized in this embodiment;

[0037] (2) The amino-modified cyclotriphosphazene flame retardant and cyanuric chloride prepared in step (1) were dissolved in a mixture of acetone and distilled water to obtain a flame retardant liquid, and then nylon 6 fabric (manufacturer: Wujiang Fuhua Weaving Co., Ltd., weight: 112.8 g / m 2 ) was immersed in a flame retardant liquid, then oscillated at 75°C for 70 minutes, and finally dried at room temperature to obtain nylon 6 fabric based on amino-modified cyclotriphosphazene flame retardant; wherein acetone accounted for 15% of the total volume of the mixed liquid of acetone and distilled water, the content of amino-modified cyclotriphosphazene flame retardant in the flame retardant liquid was 70g / L, and the content of cyanuric chloride was 40g / L.

[0038] The final nylon 6 fabric based on amino-modified cyclotriphosphazene flame retardant had a limiting oxygen index of 29.8%, a damaged length of 10.5 cm, no molten droplets were produced, and it could still pass the vertical burning test after 50 washes, with a damaged length of 14.6 cm, and no molten droplets were produced; using an 800°C muffle furnace calcination test, the residual carbon content of the nylon 6 fabric based on amino-modified cyclotriphosphazene flame retardant was 5.9%.

[0039] Comparative Example 1

[0040] A method for preparing a cyclotriphosphazene flame-retardant nylon 6 fabric is basically the same as that in Example 1, except that step (1) is not performed, and the amino-modified cyclotriphosphazene flame retardant in step (2) is replaced by a novel polyphosphazene flame retardant prepared in a document of equal quality (Preparation and flame retardant properties of modified hexachlorocyclotriphosphazene [J]. Shandong Chemical Industry, 2021, 50(1): 17-19). The preparation process of the novel polyphosphazene flame retardant is as follows: 1 g of hexachlorocyclotriphosphazene and 20 mL of toluene are added to a 250 mL three-necked flask and fully dissolved, 3.4 g of rhodamine B-amide prepared in the document is added thereto and stirred evenly, then N2 is introduced for protection and the temperature is raised to 70°C, 20 mL of triethylamine is added, and after reacting for 6 h, water is poured into the mixture to precipitate a large amount of solid, and the novel polyphosphazene flame retardant is obtained after filtration.

[0041] The cyclotriphosphazene flame-retardant nylon 6 fabric finally obtained had a limiting oxygen index of 28.2%, a damaged length of 12.1 cm, no droplets were generated, and after 5 washes, the flame retardant effect was lost and droplets were generated.

[0042] By comparing Comparative Example 1 with Example 1, it can be seen that the flame retardant performance and water washing resistance of the flame retardant nylon 6 fabric prepared in Comparative Example 1 are significantly reduced. This is because the new polyphosphazene flame retardant in Comparative Example 1 is not reactive and cannot react with cyanuric chloride. It can only be deposited on the surface of nylon 6 fabric by physical action, resulting in poor flame retardant performance of the cyclotriphosphazene flame retardant nylon 6 fabric prepared, and the flame retardant durability is greatly reduced.

[0043] Example 2

[0044] A method for preparing a flame-retardant nylon 6 fabric based on amino-modified cyclotriphosphazene, comprising the following steps:

[0045] (1) Preparation of amino-modified cyclotriphosphazene flame retardant;

[0046] Hexachlorocyclotriphosphazene and ethylenediamine were dissolved in chloroform, triethylamine was used as an acid-binding agent, the mixture was reacted at 25°C for 4.7 hours, and then the amino-modified cyclotriphosphazene flame retardant was prepared by vacuum distillation and ethanol washing; wherein the molar ratio of hexachlorocyclotriphosphazene to ethylenediamine was 1:6.2, the molar ratio of hexachlorocyclotriphosphazene to triethylamine was 1:6.3, and the mass ratio of chloroform to hexachlorocyclotriphosphazene was 33:1; the temperature of the vacuum distillation was 43°C, and the vacuum degree was 1.8 kPa;

[0047] The chemical formula of the prepared amino-modified cyclotriphosphazene flame retardant is ;

[0048] (2) The amino-modified cyclotriphosphazene flame retardant and cyanuric chloride prepared in step (1) were dissolved in a mixture of acetone and distilled water to obtain a flame retardant liquid, and then nylon 6 fabric (manufacturer: Wujiang Fuhua Weaving Co., Ltd., weight: 112.8 g / m 2 ) was immersed in a flame retardant liquid, then oscillated at 80°C for 60 minutes, and finally dried at room temperature to obtain nylon 6 fabric based on amino-modified cyclotriphosphazene flame retardant; wherein acetone accounted for 18% of the total volume of the mixed liquid of acetone and distilled water, the content of amino-modified cyclotriphosphazene flame retardant in the flame retardant liquid was 80g / L, and the content of cyanuric chloride was 45g / L.

[0049] The final nylon 6 fabric based on amino-modified cyclotriphosphazene flame retardant had a limiting oxygen index of 30.9%, a damaged length of 9.6 cm, no molten droplets were produced, and it could still pass the vertical burning test after 50 washes, with a damaged length of 14 cm and no molten droplets produced; using an 800°C muffle furnace calcination test, the residual carbon content of the nylon 6 fabric based on amino-modified cyclotriphosphazene flame retardant was 7.3%.

[0050] Example 3

[0051] A method for preparing a flame-retardant nylon 6 fabric based on amino-modified cyclotriphosphazene, comprising the following steps:

[0052] (1) Preparation of amino-modified cyclotriphosphazene flame retardant;

[0053] Dissolve hexachlorocyclotriphosphazene and ethylenediamine in chloroform, use triethylamine as an acid-binding agent, react at 28°C for 4.4 hours, and then obtain an amino-modified cyclotriphosphazene flame retardant by vacuum distillation; wherein the molar ratio of hexachlorocyclotriphosphazene to ethylenediamine is 1:6.4, the molar ratio of hexachlorocyclotriphosphazene to triethylamine is 1:6.6, and the mass ratio of chloroform to hexachlorocyclotriphosphazene is 35:1; the temperature of the vacuum distillation is 48°C, and the vacuum degree is 1.6 kPa;

[0054] The chemical formula of the prepared amino-modified cyclotriphosphazene flame retardant is ;

[0055] (2) The amino-modified cyclotriphosphazene flame retardant and cyanuric chloride prepared in step (1) were dissolved in a mixture of acetone and distilled water to obtain a flame retardant liquid, and then nylon 6 fabric (manufacturer: Wujiang Fuhua Weaving Co., Ltd., weight: 112.8 g / m 2 ) was immersed in a flame retardant liquid, then oscillated at 85°C for 50 minutes, and finally dried at room temperature to obtain nylon 6 fabric based on amino-modified cyclotriphosphazene flame retardant; wherein acetone accounted for 20% of the total volume of the mixed liquid of acetone and distilled water, the content of amino-modified cyclotriphosphazene flame retardant in the flame retardant liquid was 90g / L, and the content of cyanuric chloride was 50g / L.

[0056] The final nylon 6 fabric based on amino-modified cyclotriphosphazene flame retardant had a limiting oxygen index of 31.6%, a damaged length of 9.1 cm, no molten droplets were produced, and it could still pass the vertical burning test after 50 washes, with a damaged length of 13.4 cm and no molten droplets produced; using an 800°C muffle furnace calcination test, the residual carbon content of the nylon 6 fabric based on amino-modified cyclotriphosphazene flame retardant was 8.6%.

[0057] Example 4

[0058] A method for preparing a flame-retardant nylon 6 fabric based on amino-modified cyclotriphosphazene, comprising the following steps:

[0059] (1) Preparation of amino-modified cyclotriphosphazene flame retardant;

[0060] Hexachlorocyclotriphosphazene and ethylenediamine were dissolved in chloroform, triethylamine was used as an acid binding agent, the mixture was reacted at 30°C for 4 hours, and then the amino-modified cyclotriphosphazene flame retardant was prepared by vacuum distillation and ethanol washing; wherein the molar ratio of hexachlorocyclotriphosphazene to ethylenediamine was 1:6.6, the molar ratio of hexachlorocyclotriphosphazene to triethylamine was 1:7, and the mass ratio of chloroform to hexachlorocyclotriphosphazene was 40:1; the temperature of the vacuum distillation was 50°C, and the vacuum degree was 1.5 kPa;

[0061] The chemical formula of the prepared amino-modified cyclotriphosphazene flame retardant is ;

[0062] (2) The amino-modified cyclotriphosphazene flame retardant and cyanuric chloride prepared in step (1) were dissolved in a mixture of acetone and distilled water to obtain a flame retardant liquid, and then nylon 6 fabric (manufacturer: Wujiang Fuhua Weaving Co., Ltd., weight: 112.8 g / m 2 ) was immersed in a flame retardant liquid, then oscillated at 85°C for 55 minutes, and finally dried at room temperature to obtain nylon 6 fabric based on amino-modified cyclotriphosphazene flame retardant; wherein acetone accounted for 20% of the total volume of the mixed solution of acetone and distilled water, the content of amino-modified cyclotriphosphazene flame retardant in the flame retardant liquid was 100 g / L, and the content of cyanuric chloride was 60 g / L.

[0063] The final nylon 6 fabric based on amino-modified cyclotriphosphazene flame retardant had a limiting oxygen index of 32.3%, a damaged length of 8.7 cm, no molten droplets were produced, and it could still pass the vertical burning test after 50 washes, with a damaged length of 13.1 cm and no molten droplets produced; using an 800°C muffle furnace calcination test, the residual carbon content of the nylon 6 fabric based on amino-modified cyclotriphosphazene flame retardant was 10.2%.

Claims

1. A method for preparing a flame-retardant nylon 6 fabric based on amino-modified cyclotriphosphazene, characterized in that: The amino-modified cyclotriphosphazene flame retardant and cyanuric chloride are dissolved in an organic solvent to obtain a flame retardant liquid, and the nylon 6 fabric is immersed in the flame retardant liquid for immersion treatment to obtain the nylon 6 fabric based on the amino-modified cyclotriphosphazene flame retardant; The chemical formula of amino-modified cyclotriphosphazene flame retardant is .

2. The method for preparing a flame-retardant nylon 6 fabric based on amino-modified cyclotriphosphazene according to claim 1, characterized in that: The limiting oxygen index of nylon 6 fabric based on amino-modified cyclotriphosphazene flame retardant is not less than 29.8%, the damaged length is not higher than 10.5 cm, no molten droplets are generated, and it can still pass the vertical burning test after 50 washes, and the damaged length is not higher than 14.6 cm, and no molten droplets are generated.

3. The method for preparing a flame-retardant nylon 6 fabric based on amino-modified cyclotriphosphazene according to claim 1, characterized in that: The preparation method of the amino-modified cyclotriphosphazene flame retardant is as follows: hexachlorocyclotriphosphazene and ethylenediamine are dissolved in chloroform, triethylamine is used as an acid-binding agent, the mixture is reacted at 20-30°C for 4-5 hours, and then the amino-modified cyclotriphosphazene flame retardant is obtained by vacuum distillation and ethanol washing.

4. The method for preparing a flame-retardant nylon 6 fabric based on amino-modified cyclotriphosphazene according to claim 3, characterized in that: The molar ratio of hexachlorocyclotriphosphazene to ethylenediamine is 1:6-6.6, and the molar ratio of hexachlorocyclotriphosphazene to triethylamine is 1:6-7.

5. The method for preparing a flame-retardant nylon 6 fabric based on amino-modified cyclotriphosphazene according to claim 3, characterized in that: The temperature of reduced pressure distillation is 40~50℃, and the vacuum degree is 1.5~2.0kPa.

6. The method for preparing a flame-retardant nylon 6 fabric based on amino-modified cyclotriphosphazene according to claim 1, characterized in that: The organic solvent is a mixture of acetone and distilled water, and acetone accounts for 15-20% of the total volume of the organic solvent.

7. The method for preparing a flame-retardant nylon 6 fabric based on amino-modified cyclotriphosphazene according to claim 1, characterized in that: The content of amino-modified cyclotriphosphazene flame retardant in the flame retardant liquid is 70-100 g / L, and the content of cyanuric chloride is 40-60 g / L.

8. The method for preparing a flame-retardant nylon 6 fabric based on amino-modified cyclotriphosphazene according to claim 1, characterized in that: The bath ratio for immersion is 1:30~40; after immersion, oscillate at 75~85℃ for 50~70min.

Images