Preparation method of halogen-free flexible flame-retardant cotton fabric containing nitrogen, phosphorus and silicon

Abstract

The invention belongs to the technical field of flame retardance of cotton fabrics, and particularly discloses a preparation method of a halogen-free nitrogen-phosphorus-silicon-containing flexible flame-retardant cotton fabric, which comprises the following steps: dissolving a phosphorus-containing flame retardant in a solvent to obtain a phosphorus-containing solution; dropwise adding amino siloxane into the phosphorus-containing solution to adjust the pH value to obtain a flame-retardant solution; the washed and dried cotton fabric is soaked in the flame-retardant solution, then the soaked cotton fabric is rinsed with deionized water and then dried, and the halogen-free flexible flame-retardant cotton fabric containing nitrogen, phosphorus and silicon is obtained. The flame-retardant coating containing nitrogen-phosphorus-silicon multi-element synergistic flame retardance is constructed on the surface of the cotton fabric by using chemical bonds through a sol-gel technology, synergistic flame retardance is carried out on nitrogen-series flame retardants, phosphorus-series flame retardants and silicon-series flame retardants, and the cotton fabric is endowed with excellent flame retardance; the preparation method is green and environment-friendly, the process is simple and convenient, and the effect is remarkable.

Description

Technical Field

[0001] The invention belongs to the technical field of flame retardant cotton fabrics, and in particular relates to a method for preparing a halogen-free, nitrogen-phosphorus-silicon-containing flexible flame retardant cotton fabric. Background Art

[0002] With the development of economy and the improvement of people's living standards, the amount of cotton fabrics used in people's daily life has gradually increased, involving all aspects of production and life, such as curtains, bedding, clothing, carpets, etc. The limiting oxygen index of fabrics that have not been flame-retardant finished is 18%, while the oxygen content in the air is 21%. Therefore, once the fabrics exposed to the air are ignited, they will burn violently, causing serious damage to people's lives and property. The flammability of fabrics also greatly limits the further application of fabrics in production and life. Therefore, it is particularly important to modify the fabrics to be flame-retardant.

[0003] Flame retardant modification of fabrics can be divided into two forms: early flame retardant and late flame retardant. Early flame retardant is to directly produce flame retardant fibers or high temperature resistant fibers woven into fabrics, such as commercial products and Post-production flame retardancy is achieved by physically or chemically constructing a flame retardant coating on the surface of the fabric, such as the commercially available product Pyrovatex and The physical method mainly attaches the flame retardant to the fabric through van der Waals force and adsorption deposition, while the chemical method bonds the flame retardant to the fabric through chemical bonds. Compared with the physical method, the chemical method has better durability. Compared with the early flame retardant, the later flame retardant has become the main method for flame retardant of cotton fabrics because of its low cost, no need for process adjustment, and no great impact on the original properties of the fabric. At present, most flame retardants on the market are halogen-containing flame retardants, and the combustion of halogen-containing flame retardants will produce hydrogen halide gas, which causes serious harm to people and the environment. The green and environmentally friendly phosphorus-based and phosphorus-nitrogen-based flame retardant systems have been widely replaced by halogen flame retardants for flame retardant modification of cotton fabrics because they have the advantages of not releasing toxic gases during combustion, less smoke, and good compatibility with the substrate. However, the flame retardant efficiency of this type of flame retardant system is low, and the softness of the fabric is greatly affected, which limits its application progress. Therefore, it is very necessary to develop a new preparation method for halogen-free nitrogen-phosphorus-silicon flexible flame retardant cotton fabric. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a method for preparing a halogen-free nitrogen-phosphorus-silicon flexible flame-retardant cotton fabric. A flame-retardant coating containing nitrogen-phosphorus-silicon multi-element synergistic flame retardant is constructed on the surface of the cotton fabric by chemical bonds through sol-gel technology, and nitrogen-based, phosphorus-based, and silicon-based flame retardants are synergistically flame-retarded to give the cotton fabric excellent flame retardant properties.

[0005] In order to achieve the above purpose, one of the technical solutions of the present invention is: a method for preparing a halogen-free nitrogen-phosphorus-silicon-containing flexible flame-retardant cotton fabric, comprising the following steps:

[0006] (1) dissolving a phosphorus-containing flame retardant in a solvent to obtain a phosphorus-containing solution; adding aminosilicone to the phosphorus-containing solution to adjust the pH value to obtain a flame retardant solution;

[0007] (2) The washed and dried cotton fabric is immersed in a flame retardant solution, and then the immersed cotton fabric is rinsed with deionized water and dried to obtain a halogen-free nitrogen-phosphorus-silicon-containing flexible flame retardant cotton fabric.

[0008] In a preferred embodiment of the present invention, the phosphorus-containing flame retardant in step (1) is one or a combination of phenylphosphonic acid, diphenylphosphonic acid, 4-methoxyphenylphosphonic acid, p-methylphenylphosphonic acid, and biphenyl-4,4-diphosphonic acid.

[0009] In a preferred embodiment of the present invention, the content of phosphorus-containing flame retardant in the flame retardant solution in step (1) is 1-12 wt%.

[0010] In a preferred embodiment of the present invention, the solvent in step (1) is deionized water.

[0011] In a preferred embodiment of the present invention, the aminosilicone in step (1) is one or more of 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, 3-aminopropylmethyldiethoxysilane and 3-(2-aminoethylamino)propyltrimethoxysilane.

[0012] In a preferred embodiment of the present invention, the pH value in step (1) is 5-7.

[0013] In a preferred embodiment of the present invention, the drying temperature in step (2) is 100-140° C. and the drying time is 4-6 hours.

[0014] In order to achieve the above purpose, the second technical solution of the present invention is: a halogen-free nitrogen-phosphorus-silicon-containing flexible flame-retardant cotton fabric prepared by a preparation method of a halogen-free nitrogen-phosphorus-silicon-containing flexible flame-retardant cotton fabric.

[0015] In order to achieve the above objectives, the third technical solution of the present invention is: application of a method for preparing halogen-free nitrogen-phosphorus-silicon-containing flexible flame-retardant cotton fabric in flame-retardant modification of cotton fabric.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The present invention uses sol-gel technology to construct a flame-retardant coating containing nitrogen-phosphorus-silicon multi-element synergistic flame retardant on the surface of cotton fabric with chemical bonds, and synergistically flame retards nitrogen, phosphorus and silicon flame retardants to give cotton fabric excellent flame retardant properties;

[0018] 2. The preparation method of the present invention is green and environmentally friendly, has a simple process and significant effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a sample picture of the halogen-free nitrogen-phosphorus-silicon-containing flexible flame-retardant cotton fabric prepared in Example 1-4 after the UL-94 vertical burning test;

[0020] Figure 2 These are pictures demonstrating the softness of cotton fabrics before and after flame retardant treatment in Examples 1-4. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is described in more detail below with reference to the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited to these embodiments.

[0022] A method for preparing a halogen-free, nitrogen-phosphorus-silicon-containing flexible flame-retardant cotton fabric comprises the following steps:

[0023] (1) dissolving a phosphorus-containing flame retardant in a solvent to obtain a phosphorus-containing solution; adding aminosilicone to the phosphorus-containing solution to adjust the pH value to obtain a flame retardant solution;

[0024] (2) The washed and dried cotton fabric is immersed in a flame retardant solution, and then the immersed cotton fabric is rinsed with deionized water and dried to obtain a halogen-free nitrogen-phosphorus-silicon-containing flexible flame retardant cotton fabric.

[0025] The phosphorus-containing flame retardant in step (1) is one or a combination of phenylphosphonic acid, diphenylphosphonic acid, 4-methoxyphenylphosphonic acid, p-methylphenylphosphonic acid, and biphenyl-4,4-diphosphonic acid.

[0026] The content of phosphorus-containing flame retardant in the flame retardant solution in step (1) is 1-12 wt %.

[0027] The solvent in step (1) is deionized water.

[0028] The aminosiloxane in step (2) is 3-aminopropyltriethoxysilane.

[0029] The pH value in the step (2) is 5-7.

[0030] In the step (3), the drying temperature is 100-140° C. and the drying time is 4-6 hours.

[0031] The invention discloses a method for preparing a halogen-free, nitrogen-phosphorus-silicon-containing flexible flame-retardant cotton fabric, and obtains a halogen-free, nitrogen-phosphorus-silicon-containing flexible flame-retardant cotton fabric.

[0032] A method for preparing halogen-free nitrogen-phosphorus-silicon-containing flexible flame-retardant cotton fabric is used in flame-retardant modification of cotton fabric.

[0033] Example 1

[0034] A halogen-free, nitrogen-phosphorus-silicon-containing flexible flame-retardant cotton fabric, the preparation method of which is as follows:

[0035] (1) dissolving an appropriate amount of phenylphosphonic acid in deionized water to prepare a phenylphosphonic acid solution with a mass fraction of 3 wt %;

[0036] (2) adding 3-aminopropyltriethoxysilane to the above phenylphosphonic acid solution to adjust the pH of the system to 6, thereby obtaining a flame retardant solution; (3) immersing the washed and dried cotton fabric in the flame retardant solution prepared above, and after 10 minutes, rinsing the immersed cotton fabric with deionized water once, and then placing it in an oven at 140° C. for 4 hours to obtain a halogen-free nitrogen-phosphorus-silicon-containing flexible flame retardant cotton fabric.

[0037] Example 2

[0038] A halogen-free, nitrogen-phosphorus-silicon-containing flexible flame-retardant cotton fabric, the preparation method of which is as follows:

[0039] (1) dissolving an appropriate amount of phenylphosphonic acid in deionized water to prepare a phenylphosphonic acid solution with a mass concentration of 6 wt %;

[0040] (2) adding 3-aminopropyltriethoxysilane to the above phenylphosphonic acid solution to adjust the pH of the system to 6, thereby obtaining a flame retardant solution; (3) immersing the washed and dried cotton fabric in the flame retardant solution prepared above, and after 10 minutes, rinsing the immersed cotton fabric with deionized water once, and then placing it in an oven at 140° C. for 4 hours to obtain a halogen-free nitrogen-phosphorus-silicon-containing flexible flame retardant cotton fabric.

[0041] Example 3

[0042] A halogen-free, nitrogen-phosphorus-silicon-containing flexible flame-retardant cotton fabric, the preparation method of which is as follows:

[0043] (1) dissolving an appropriate amount of phenylphosphonic acid in deionized water to prepare a phenylphosphonic acid solution with a mass concentration of 9 wt %;

[0044] (2) adding 3-aminopropyltriethoxysilane to the above phenylphosphonic acid solution to adjust the pH of the system to 6, thereby obtaining a flame retardant solution; (3) immersing the washed and dried cotton fabric in the flame retardant solution prepared above, and after 10 minutes, rinsing the immersed cotton fabric with deionized water once, and then placing it in an oven at 140° C. for 4 hours to obtain a halogen-free nitrogen-phosphorus-silicon-containing flexible flame retardant cotton fabric coating.

[0045] Example 4

[0046] A halogen-free, nitrogen-phosphorus-silicon-containing flexible flame-retardant cotton fabric, the preparation method of which is as follows:

[0047] (1) dissolving an appropriate amount of phenylphosphonic acid in deionized water to prepare a phenylphosphonic acid solution with a mass concentration of 11 wt %;

[0048] (2) adding 3-aminopropyltriethoxysilane to the above phenylphosphonic acid solution to adjust the pH of the system to 6, thereby obtaining a flame retardant solution; (3) immersing the washed and dried cotton fabric in the flame retardant solution prepared above, and after 10 minutes, rinsing the immersed cotton fabric with deionized water once, and then placing it in an oven at 140° C. for 4 hours to obtain a halogen-free nitrogen-phosphorus-silicon-containing flexible flame retardant cotton fabric.

[0049] The halogen-free nitrogen-phosphorus-silicon-containing flexible flame-retardant cotton fabrics prepared in Examples 1-4 were subjected to oxygen index and UL-94 vertical burning tests, and their weight loss rate was tested by TGA thermogravimeter in a nitrogen environment at 10°C / min and heated to 800°C. The softness of the fabric after flame retardant treatment was characterized by a self-weight bending test. The specific values ​​are shown in Table 1 below:

[0050] Table 1 Performance test results of halogen-free nitrogen-phosphorus-silicon-containing flexible flame-retardant cotton fabrics prepared in Examples 1-4

[0051]

[0052] It can be seen from the performance test results of Table 1 above that the cotton fabric (original fabric) without flame retardant treatment has almost no residual carbon after burning, and in the combustion experiment, it burns violently once ignited, the flame spreads very quickly, and it burns completely in a short time. The flame-retardant cotton fabrics of Examples 1-4 can delay the combustion process even at a low weight gain rate, reduce the flame spread rate, and form a complete carbon layer after burning. When the addition amount of phosphorus-containing flame retardant phenylphosphonic acid is 9wt%, it passes the V0 level, achieves self-extinguishing from the fire, and significantly reduces the damage length, which shows that the generated carbon layer has a certain stability and basically does not continue to decompose at high temperature. When the addition amount of phosphorus-containing flame retardant phenylphosphonic acid is 11wt%, its flame retardant performance is further improved. It shows that the phosphorus-containing flame retardant is the main flame retardant, aminosiloxane is a coupling agent and a secondary flame retardant, and a flame retardant coating containing nitrogen-phosphorus-silicon multi-element synergistic flame retardant is constructed on the surface of the cotton fabric by chemical bonds through a simple sol-gel technology, giving the cotton fabric excellent flame retardant performance.

[0053] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a halogen-free, nitrogen-phosphorus-silicon-containing flexible flame-retardant cotton fabric, characterized in that: The steps include: (1) dissolving a phosphorus-containing flame retardant in a solvent to obtain a phosphorus-containing solution; adding aminosilicone to the phosphorus-containing solution to adjust the pH value to obtain a flame retardant solution; (2) The washed and dried cotton fabric is immersed in a flame retardant solution, and then the immersed cotton fabric is rinsed with deionized water and dried to obtain a halogen-free nitrogen-phosphorus-silicon-containing flexible flame retardant cotton fabric.

2. The method for preparing the halogen-free nitrogen-phosphorus-silicon-containing flexible flame-retardant cotton fabric according to claim 1, characterized in that: The phosphorus-containing flame retardant in step (1) is one or a combination of phenylphosphonic acid, diphenylphosphonic acid, 4-methoxyphenylphosphonic acid, p-methylphenylphosphonic acid, and biphenyl-4,4-diphosphonic acid.

3. The method for preparing the halogen-free nitrogen-phosphorus-silicon-containing flexible flame-retardant cotton fabric according to claim 1, characterized in that: In the step (1), the content of phosphorus-containing flame retardant in the flame retardant solution is 1-12 wt%.

4. The method for preparing the halogen-free nitrogen-phosphorus-silicon-containing flexible flame-retardant cotton fabric according to claim 1, characterized in that: The solvent in step (1) is deionized water.

5. The method for preparing the halogen-free nitrogen-phosphorus-silicon-containing flexible flame-retardant cotton fabric according to claim 1, characterized in that: The aminosiloxane in step (1) is one or more of 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, 3-aminopropylmethyldiethoxysilane and 3-(2-aminoethylamino)propyltrimethoxysilane.

6. The method for preparing the halogen-free nitrogen-phosphorus-silicon-containing flexible flame-retardant cotton fabric according to claim 1, characterized in that: The pH value in the step (1) is 5-7.

7. The method for preparing the halogen-free nitrogen-phosphorus-silicon-containing flexible flame-retardant cotton fabric according to claim 1, characterized in that: In the step (2), the drying temperature is 100-140° C. and the drying time is 4-6 hours.

8. A halogen-free, nitrogen-containing, phosphorus-silicon-containing flexible flame-retardant cotton fabric obtained by the method for preparing a halogen-free, nitrogen-containing, phosphorus-silicon-containing flexible flame-retardant cotton fabric as claimed in any one of claims 1 to 7.

9. Use of the method for preparing halogen-free nitrogen-phosphorus-silicon-containing flexible flame-retardant cotton fabric according to any one of claims 1 to 7 in flame-retardant modification of cotton fabric.

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