Preparation method of polyester / cotton blended fabric with permanent flame retardant and smoke suppression functions

Abstract

The present invention relates to a preparation method of a durable flame-retardant and smoke-suppressing polyester / cotton blended fabric. The polyester / cotton blended fabric is immersed in a flame-retardant finishing solution, and a durable flame-retardant and smoke-suppressing polyester / cotton blended fabric is obtained through a padding and baking process. The flame-retardant finishing solution is obtained by adding dicyandiamide to a phosphorus / nitrogen / silicon flame retardant solution. The preparation method of the phosphorus / nitrogen / silicon flame retardant solution is as follows: First, diethylenetriamine pentamethylene phosphonic acid and polyvinyl alcohol are dissolved in water, and ammonia water is added to adjust the pH value of the solution to 6-8 to obtain a mixed solution. Then, an ethanol solution of tetraethyl orthosilicate is dropped into the mixed solution at a rate of 0.5-1 mL / min, and a phosphorus / nitrogen / silicon flame retardant solution is obtained through reaction. In the present invention, the phosphorus / nitrogen / silicon flame retardant is firmly grafted onto the polyester / cotton blended fabric through the adhesion ability of the polyvinyl alcohol film itself and the covalent bond reaction with cotton fibers, and the obtained product has excellent flame-retardant performance and smoke-suppressing performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of flame-retardant polyester / cotton blended fabrics, and relates to a preparation method of a polyester / cotton blended fabric with a persistent flame-retardant and smoke-suppressing function. Background Art

[0002] Polyester / cotton blended fabric is a kind of fabric spun from polyester and cotton fibers. It combines the advantages of polyester and cotton fibers, not only having good elasticity and abrasion resistance, but also having characteristics such as stable dimensions, small shrinkage rate, bright luster, smooth hand feeling and stiffness. Polyester / cotton blended fabrics are widely used in home textiles, bedding, work clothes in the fields of fire protection, petroleum, electric power, natural gas, etc. Therefore, strict requirements are imposed on the flame-retardant performance of polyester / cotton blended fabrics. However, there is a "scaffold effect" during the combustion process of polyester / cotton blended fabrics, resulting in higher flammability and combustibility, so there is a high demand for flame-retardant finishing.

[0003] In response to the flame-retardant finishing requirements of polyester / cotton blended fabrics, many methods have been proposed. Literature 1 (Application of new flame retardants in polyester / cotton blended fabrics [J]. Dyeing and Finishing Technology, 2021, 43(10): 25-28) uses a flame retardant / crosslinking agent system for polyester and cotton to carry out flame-retardant modification on polyester / cotton blended fabrics; among them, the cotton flame retardant in this technical solution crosslinks with cotton fibers, and the polyester flame retardant combines with polyester fabrics through the principle of similar solubility. Therefore, the modified polyester / cotton blended fabric can withstand 20 washes. However, the two flame retardants act independently, with low flame-retardant efficiency and limited grafting degree, and its wash resistance needs to be further improved.

[0004] Literature 2 (Research and development of flame-retardant polyester fabrics based on phosphates [J]. Modern Silk Science & Technology, 2020, 35(3): 4-6, 40.) uses phytic acid and polyvinyl alcohol to synthesize a linear phosphate flame retardant through an esterification reaction (that is, phytic acid is grafted on polyvinyl alcohol as a flame retardant), but the phosphate flame retardant is coated on the fabric surface, and the polyvinyl alcohol in it forms a film, which is physically adhered to the fabric, and the wash resistance is poor and still needs to be further improved.

[0005] In addition, Chinese invention patent CN117364487A discloses a preparation method of a persistent flame-retardant coated polyester / cotton blended fabric. After dissolving polyvinyl alcohol, N-(phosphonomethyl)iminodiacetic acid, diethyl hydroxymethylphosphonate, sodium hypophosphite and triethanolamine in distilled water to prepare a flame-retardant finishing solution, the polyester / cotton blended fabric is treated by the method of padding-baking to obtain a persistent flame-retardant coated polyester / cotton blended fabric; however, the flame-retardant efficiency of the flame-retardant system is poor, and a higher amount of flame retardant is required.

[0006] Therefore, it is of great significance to study a preparation method of a polyester / cotton blended fabric with a persistent flame-retardant and smoke-suppressing function to solve the problems existing in the prior art. Summary of the Invention

[0007] The object of the present invention is to solve the problems existing in the prior art and provide a preparation method of a polyester / cotton blended fabric with a persistent flame retardant and smoke suppression function.

[0008] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0009] A preparation method of a polyester / cotton blended fabric with a persistent flame retardant and smoke suppression function, wherein the polyester / cotton blended fabric is immersed in a flame retardant finishing solution, and a polyester / cotton blended fabric with a persistent flame retardant and smoke suppression function is obtained through a pad-dry-cure process. The flame retardant finishing solution is obtained by adding dicyandiamide to a phosphorus / nitrogen / silicon flame retardant solution.

[0010] The preparation method of the phosphorus / nitrogen / silicon flame retardant solution is as follows: First, diethylenetriamine pentamethylene phosphonic acid and polyvinyl alcohol are dissolved in water, and ammonia water is added to adjust the pH value of the solution to 6-8 to obtain a mixed solution, so that part of the phosphate groups of diethylenetriamine pentamethylene phosphonic acid are converted into ammonium phosphate groups, which helps the subsequent formation of silica sol from tetraethyl orthosilicate and also helps the subsequent covalent grafting reaction. Then, an ethanol solution of tetraethyl orthosilicate is added dropwise to the mixed solution at a rate of 0.5-1 mL / min. The dropwise addition helps to promote the hydrolysis and condensation reaction of tetraethyl orthosilicate after contacting with water to form silica sol, and the reaction obtains the phosphorus / nitrogen / silicon flame retardant solution.

[0011] As a preferred technical solution:

[0012] For the preparation method of a polyester / cotton blended fabric with a persistent flame retardant and smoke suppression function as described above, the pad-dry-cure process is specifically as follows: The two-dip two-roll method is adopted, and the liquor pickup rate is 90-110%; the pre-drying temperature is 70-90 °C, and the time is 2-3 min. The curing temperature is 160-170 °C, and the time is 3-4 min. A higher curing temperature helps to promote the covalent grafting reaction between the ammonium phosphate groups of diethylenetriamine pentamethylene phosphonic acid and the hydroxyl groups of cotton fibers and polyvinyl alcohol, but too high a temperature causes greater damage to the physical properties of the fabric.

[0013] For the preparation method of a polyester / cotton blended fabric with a persistent flame retardant and smoke suppression function as described above, the content of polyester in the polyester / cotton blended fabric is 20-80%.

[0014] For the preparation method of a polyester / cotton blended fabric with a persistent flame retardant and smoke suppression function as described above, the content of dicyandiamide in the flame retardant finishing solution is 30-50 g / L. Dicyandiamide can be used as a catalyst to promote the covalent grafting reaction between the phosphate groups of diethylenetriamine pentamethylene phosphonic acid in the mixed solution and the hydroxyl groups of cotton fibers and polyvinyl alcohol.

[0015] As described above, in the preparation method of a polyester / cotton blended fabric with durable flame retardancy and smoke suppression function, the content of diethylenetriaminepenta(methylenephosphonic acid) in the mixed solution is 75-100 g / L, and diethylenetriaminepenta(methylenephosphonic acid) is the main flame retardant component. The higher the amount used, the better the flame retardant performance, but too high a content is wasteful; the content of polyvinyl alcohol is 30-60 g / L.

[0016] In the method for preparing a polyester / cotton blended fabric with durable flame retardancy and smoke suppression function as described above, the content of tetraethyl orthosilicate in the phosphorus / nitrogen / silicon flame retardant solution is 20-40 g / L.

[0017] In the method for preparing a polyester / cotton blended fabric with durable flame retardancy and smoke suppression function as described above, in the ethanol solution of tetraethyl orthosilicate, the mass ratio of tetraethyl orthosilicate to ethanol is 1-2:1.

[0018] In the method for preparing a polyester / cotton blended fabric with durable flame retardancy and smoke suppression function as described above, the ethanol solution of tetraethyl orthosilicate is added at a rate of 0.5-1 mL / min, and the reaction is continued for 2-3 hours after the addition is completed.

[0019] The method for preparing a polyester / cotton blended fabric with a durable flame retardant and smoke suppression function as described above, wherein the limiting oxygen index of the polyester / cotton blended fabric with a durable flame retardant and smoke suppression function is not less than 31.5%, the damaged length is not higher than 8.9 cm, and the total amount of smoke released is not higher than 0.48 m 2 After 40 washes, the damaged length is still no more than 14.5cm, meeting the B1 standard (the limiting oxygen index of unmodified polyester / cotton blended fabric is 19.2%, the damaged length is 30cm, and the total smoke release is 0.74m 2 ).

[0020] The principle of the present invention is:

[0021] The phosphate group of diethylenetriamine penta(methylenephosphonic acid) can undergo an esterification cross-linking reaction with the hydroxyl group of cotton fiber under the catalysis of dicyandiamide, thereby grafting the phosphorus-containing flame retardant group onto the cotton fiber. However, the cotton fiber component content in polyester / cotton blended fabrics is limited, and it is difficult to graft a sufficient amount of phosphorus-containing flame retardant onto the polyester / cotton blended fabric, and it is impossible to provide lasting flame retardant properties. In addition, the phosphorus-containing flame retardant alone causes the smoke release of polyester / cotton blended fabrics to increase, thereby increasing the fire hazard.

[0022] In the present invention, the silanol groups formed by hydrolysis of the siloxane structure of tetraethyl orthosilicate undergo hydrolysis and condensation in an aqueous solution to generate a network-like silica sol, and the silanol groups can react with the phosphate groups of diethylenetriaminepenta(methylenephosphonic acid) and the hydroxyl groups of polyvinyl alcohol after hydrolysis, so that a new network-like phosphorus / nitrogen / silicon flame retardant is formed between the silicon-containing network, diethylenetriaminepenta(methylenephosphonic acid) (including a part of ammonium diethylenetriaminepenta(methylenephosphonic acid) converted from diethylenetriaminepenta(methylenephosphonic acid), and polyvinyl alcohol;

[0023] As Figure 1 shown, under the catalysis of dicyandiamide, the phosphate groups in the network - shaped phosphorus / nitrogen / silicon flame retardant can undergo an esterification cross - linking reaction with the hydroxyl groups of cotton fibers in the polyester / cotton blended fabric and the hydroxyl groups of polyvinyl alcohol (polyvinyl alcohol includes both the polyvinyl alcohol molecular chains in the network - shaped phosphorus / nitrogen / silicon flame retardant itself and the polyvinyl alcohol that may not have reacted before). Moreover, polyvinyl alcohol can form a film on the surface of the polyester / cotton blended fabric. Under baking conditions, the hydroxyl groups within its molecules dehydrate to form ether - bond structures, enhancing the adhesion to the polyester / cotton blended fabric. Therefore, the network - shaped phosphorus / nitrogen / silicon flame retardant is firmly grafted onto the polyester / cotton blended fabric through the adhesion ability of the polyvinyl alcohol film itself and the covalent - bond reaction with cotton fibers, thereby providing durable flame - retardant properties;

[0024] In addition, the phosphate groups in the network - shaped phosphorus / nitrogen / silicon flame retardant act as acid sources, the ammonium groups act as gas sources, and the polyvinyl alcohol acts as a carbon source, organically combining to construct an intumescent flame - retardant system. It has a high flame - retardant efficiency, and the silicon - containing flame - retardant groups help to further improve the flame - retardant properties and have the ability to inhibit smoke release. Therefore, the polyester / cotton blended fabric modified by the coating has excellent flame - retardant and smoke - suppression properties.

[0025] Beneficial effects:

[0026] (1) In the preparation method of a polyester / cotton blended fabric with a durable flame - retardant and smoke - suppression function of the present invention, the silicon hydroxyl groups formed by the hydrolysis of the siloxane structure of tetraethyl orthosilicate undergo hydrolysis condensation in an aqueous solution to form a network - shaped silica sol. Moreover, after hydrolysis, the silicon hydroxyl groups can react with the phosphate groups of diethylenetriamine pentamethylene phosphonic acid and the hydroxyl groups of polyvinyl alcohol to form a new network - shaped phosphorus / nitrogen / silicon flame retardant. The network - shaped phosphorus / nitrogen / silicon flame retardant is firmly grafted onto the polyester / cotton blended fabric through the adhesion ability of the polyvinyl alcohol film itself and the covalent - bond reaction with cotton fibers, thereby providing durable flame - retardant properties.

[0027] (2) In the preparation method of a polyester / cotton blended fabric with a durable flame - retardant and smoke - suppression function of the present invention, the phosphate groups in the network - shaped phosphorus / nitrogen / silicon flame retardant act as acid sources, the ammonium groups act as gas sources, and the polyvinyl alcohol acts as a carbon source, organically combining to construct an intumescent flame - retardant system. It has a high flame - retardant efficiency, and the silicon - containing flame - retardant groups help to further improve the flame - retardant properties and have the ability to inhibit smoke release. Therefore, the polyester / cotton blended fabric modified by the coating has excellent flame - retardant and smoke - suppression properties. Description of the drawings

[0028] Figure 1 It is a schematic diagram of the cross - linking mechanism between the network - shaped phosphorus / nitrogen / silicon flame retardant and the polyester / cotton blended fabric;

[0029] Figure 2Comparison chart of smoke release curves between a polyester / cotton blended fabric and a polyester / cotton blended fabric with a durable flame retardant and smoke suppression function in Example 3 (i.e., the coated polyester / cotton blended fabric in the figure). Detailed implementation manners

[0030] The present invention will be further described below in conjunction with specific implementation manners. It should be understood that these examples are only used to illustrate the present invention and not 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 also fall within the scope defined by the appended claims of this application.

[0031] The test methods for the performance indicators in the examples and comparative examples of the present invention are as follows:

[0032] Damaged length: It is measured with reference to the standard of GB / T 5455-2014 "Textiles - Burning performance - Determination of damaged length, smoldering and afterflaming time in vertical direction".

[0033] Total smoke release: The total smoke release of the sample is tested and characterized by using a VOUCH 6810 cone calorimeter with reference to the ISO 5660-1 standard.

[0034] Damaged length after 40 washes: First, the fabric is washed 40 times with reference to the standard of AATCC 61-2013 "Accelerated test for colorfastness to laundering - Home and commercial", and then the damaged length of the fabric is tested with reference to the standard of GB / T 5455-2014 "Textiles - Burning performance - Determination of damaged length, smoldering and afterflaming time in vertical direction".

[0035] Example 1

[0036] A preparation method of a polyester / cotton blended fabric with a durable flame retardant and smoke suppression function, the specific steps are as follows:

[0037] (1) First, diethylenetriamine pentamethylenephosphonic acid and polyvinyl alcohol of type 1788 are dissolved in water, and ammonia water is added to adjust the pH value of the solution to 6 to obtain a mixed solution. Then, an ethanol solution of tetraethyl orthosilicate is added dropwise to the mixed solution at a rate of 0.5 mL / min. After the addition is completed, the reaction is continued for 2 h to obtain a phosphorus / nitrogen / silicon flame retardant solution;

[0038] Among them, in the mixed solution, the content of diethylenetriamine pentamethylenephosphonic acid is 75 g / L, and the content of polyvinyl alcohol is 30 g / L; in the ethanol solution of tetraethyl orthosilicate, the mass ratio of tetraethyl orthosilicate to ethanol is 1:1; in the phosphorus / nitrogen / silicon flame retardant solution, the content of tetraethyl orthosilicate is 20 g / L;

[0039] (2) Add dicyandiamide to the phosphorus / nitrogen / silicon flame retardant solution to obtain a flame retardant finishing solution; the content of dicyandiamide in the flame retardant finishing solution is 30 g / L;

[0040] (3) Immerse a polyester / cotton blended fabric with a polyester content of 20 wt% into the flame retardant finishing solution, and perform two-bath two-roll and baking treatments in sequence to obtain a polyester / cotton blended fabric with durable flame retardant and smoke suppression functions;

[0041] Among them, the expression rate is 90%; the process parameters of baking are as follows: the pre-baking temperature is 70 °C, the time is 3 min, the curing temperature is 170 °C, and the time is 3 min.

[0042] The limiting oxygen index of the finally obtained polyester / cotton blended fabric with durable flame retardant and smoke suppression functions is 31.5%, the damage length is 8.9 cm, and the total smoke release amount is 0.48 m 2 , and the damage length is 14.5 cm after 40 washes.

[0043] Comparative Example 1

[0044] A method for preparing a modified polyester / cotton blended fabric is basically the same as that in Example 1, except that polyvinyl alcohol is not added in step (1).

[0045] The limiting oxygen index of the finally obtained modified polyester / cotton blended fabric is 29.9%, the damage length is 9.5 cm, and the total smoke release amount is 0.55 m 2 , and the damage length is 30 cm after 20 washes.

[0046] Comparing Comparative Example 1 with Example 1, it can be found that when polyvinyl alcohol is not added, the flame retardant performance and wash resistance of the modified polyester / cotton blended fabric are reduced. This is because the content of the cotton fiber component in the polyester / cotton blended fabric is limited, and it is difficult to graft a sufficient amount of phosphorus-containing flame retardant onto the polyester / cotton blended fabric, so a durable flame retardant performance cannot be provided.

[0047] Comparative Example 2

[0048] A method for preparing a modified polyester / cotton blended fabric is basically the same as that in Example 1, except that the ethanol solution of tetraethyl orthosilicate is not added in step (1).

[0049] The limiting oxygen index of the finally obtained modified polyester / cotton blended fabric is 30.8%, the damage length is 9.1 cm, and the total smoke release amount is 0.81 m 2 , and the damage length is 30 cm after 30 washes.

[0050] Comparing Comparative Example 2 with Example 1, it can be found that when the ethanol solution of tetraethyl orthosilicate is not added, the flame retardancy of the modified polyester / cotton blended fabric decreases, the wash resistance decreases, and the smoke release amount increases significantly. This is because the silicon-containing network not only helps to form a phosphorus / nitrogen / silicon synergistic flame retardancy effect to further improve the flame retardancy efficiency, but also can form inorganic oxides to inhibit smoke release.

[0051] Example 2

[0052] A preparation method of a durable flame-retardant and smoke-suppressing functional polyester / cotton blended fabric is as follows:

[0053] (1) First, diethylenetriamine pentamethylenephosphonic acid and polyvinyl alcohol of type 1788 are dissolved in water, and ammonia water is added to adjust the pH value of the solution to 6.5 to obtain a mixed solution. Then, the ethanol solution of tetraethyl orthosilicate is added dropwise to the mixed solution at a rate of 0.7 mL / min. After the addition is completed, the reaction is continued for 2.5 h to obtain a phosphorus / nitrogen / silicon flame retardant solution;

[0054] Among them, in the mixed solution, the content of diethylenetriamine pentamethylenephosphonic acid is 80 g / L, and the content of polyvinyl alcohol is 40 g / L; in the ethanol solution of tetraethyl orthosilicate, the mass ratio of tetraethyl orthosilicate to ethanol is 1.3:1; in the phosphorus / nitrogen / silicon flame retardant solution, the content of tetraethyl orthosilicate is 25 g / L;

[0055] (2) Add dicyandiamide to the phosphorus / nitrogen / silicon flame retardant solution to obtain a flame retardant finishing solution; the content of dicyandiamide in the flame retardant finishing solution is 35 g / L;

[0056] (3) Immerse the polyester / cotton blended fabric with a polyester content of 35 wt% into the flame retardant finishing solution, and perform two-bath two-roll and baking treatments in sequence to obtain a durable flame-retardant and smoke-suppressing functional polyester / cotton blended fabric;

[0057] Among them, the pick-up rate is 95%; the process parameters of baking are as follows: the pre-baking temperature is 75 °C, the time is 2.8 min, the curing temperature is 160 °C, and the time is 4 min.

[0058] The limiting oxygen index of the finally obtained durable flame-retardant and smoke-suppressing functional polyester / cotton blended fabric is 32.8%, the damage length is 8.5 cm, and the total smoke release amount is 0.41 m 2 , and the damage length is 13.6 cm after 40 washes.

[0059] Example 3

[0060] A preparation method of a durable flame-retardant and smoke-suppressing functional polyester / cotton blended fabric is as follows:

[0061] (1) First, dissolve diethylenetriamine pentamethylenephosphonic acid and polyvinyl alcohol of type 1788 in water, add ammonia water to adjust the pH value of the solution to 7 to obtain a mixed solution, and then dropwise add an ethanol solution of tetraethyl orthosilicate to the mixed solution at a rate of 0.85 mL / min. After the dropping is completed, continue the reaction for 2.75 h to obtain a phosphorus / nitrogen / silicon flame retardant solution;

[0062] Among them, in the mixed solution, the content of diethylenetriamine pentamethylenephosphonic acid is 90 g / L, and the content of polyvinyl alcohol is 50 g / L; in the ethanol solution of tetraethyl orthosilicate, the mass ratio of tetraethyl orthosilicate to ethanol is 1.7:1; in the phosphorus / nitrogen / silicon flame retardant solution, the content of tetraethyl orthosilicate is 30 g / L;

[0063] (2) Add dicyandiamide to the phosphorus / nitrogen / silicon flame retardant solution to obtain a flame retardant finishing solution; the content of dicyandiamide in the flame retardant finishing solution is 40 g / L;

[0064] (3) Immerse a polyester / cotton blended fabric with a polyester content of 50 wt% into the flame retardant finishing solution, and carry out two-dip two-roll and baking treatments in sequence to obtain a polyester / cotton blended fabric with a permanent flame retardant and smoke suppression function;

[0065] Among them, the expression rate is 100%; the process parameters of baking are as follows: the pre-baking temperature is 80 °C, the time is 2.5 min, the curing temperature is 165 °C, and the time is 3.5 min.

[0066] The limiting oxygen index of the finally obtained polyester / cotton blended fabric with a permanent flame retardant and smoke suppression function is 33.6%, the damage length is 8.2 cm, and the damage length after 40 washes is 13.1 cm. As Figure 2 shown, the total smoke release amount of the polyester / cotton blended fabric is 0.74 m 2 , and the total smoke release amount of the polyester / cotton blended fabric with a permanent flame retardant and smoke suppression function is 0.40 m 2 .

[0067] Example 4

[0068] A preparation method of a polyester / cotton blended fabric with a permanent flame retardant and smoke suppression function, the specific steps are as follows:

[0069] (1) First, dissolve diethylenetriamine pentamethylenephosphonic acid and polyvinyl alcohol of type 1788 in water, add ammonia water to adjust the pH value of the solution to 8 to obtain a mixed solution, and then dropwise add an ethanol solution of tetraethyl orthosilicate to the mixed solution at a rate of 1 mL / min. After the dropping is completed, continue the reaction for 3 h to obtain a phosphorus / nitrogen / silicon flame retardant solution;

[0070] Among them, in the mixed solution, the content of diethylenetriamine pentamethylenephosphonic acid is 100 g / L, and the content of polyvinyl alcohol is 60 g / L; in the ethanol solution of tetraethyl orthosilicate, the mass ratio of tetraethyl orthosilicate to ethanol is 2:1; in the phosphorus / nitrogen / silicon flame retardant solution, the content of tetraethyl orthosilicate is 40 g / L;

[0071] (2) Add dicyandiamide to the phosphorus / nitrogen / silicon flame retardant solution to obtain a flame retardant finishing solution; the content of dicyandiamide in the flame retardant finishing solution is 50 g / L;

[0072] (3) Immerse the polyester / cotton blended fabric with 80% polyester content into the flame retardant finishing solution, and carry out two-dip two-roll and baking treatments in sequence to obtain a polyester / cotton blended fabric with permanent flame retardant and smoke suppression functions;

[0073] Among them, the liquor pickup rate is 105%; the process parameters of baking are as follows: the pre-baking temperature is 90 °C, the time is 2 min, the curing temperature is 170 °C, and the time is 3.2 min.

[0074] The limiting oxygen index of the finally obtained polyester / cotton blended fabric with permanent flame retardant and smoke suppression functions is 34.1%, the damage length is 7.9 cm, and the total smoke release is 0.33 m 2 After 40 washes, the damage length is 12.8 cm.

Claims

1. A method for preparing a polyester / cotton blended fabric with a durable flame retardant and smoke suppression function, comprising immersing the polyester / cotton blended fabric in a flame retardant finishing liquid, and performing a rolling and baking process to obtain a polyester / cotton blended fabric with a durable flame retardant and smoke suppression function, wherein: The flame retardant finishing liquid is obtained by adding dicyandiamide to a phosphorus / nitrogen / silicon flame retardant solution; The preparation method of the phosphorus / nitrogen / silicon flame retardant solution is as follows: firstly, diethylenetriamine penta (methylene phosphonic acid) and polyvinyl alcohol are dissolved in water, and ammonia water is added to adjust the pH value of the solution to 6-8 to obtain a mixed solution, and then an ethanol solution of tetraethyl orthosilicate is added dropwise at a rate of 0.5-1 mL / min to the mixed solution to react and obtain a phosphorus / nitrogen / silicon flame retardant solution, wherein the rate of adding the ethanol solution of tetraethyl orthosilicate is 0.5-1 mL / min, and the reaction is continued for 2-3 hours after the addition is completed.

2. The method for preparing a polyester / cotton blended fabric with durable flame retardancy and smoke suppression function according to claim 1, characterized in that: The specific rolling and baking process is: adopting a two-immersion and two-rolling method, with a rolling rate of 90-110%; the pre-baking temperature is 70-90°C, the time is 2-3 minutes, and the baking temperature is 160-170°C, and the time is 3-4 minutes.

3. The method for preparing a polyester / cotton blended fabric with durable flame retardancy and smoke suppression function according to claim 1, characterized in that: The polyester content in polyester / cotton blended fabrics is 20-80%.

4. The method for preparing a polyester / cotton blended fabric with durable flame retardancy and smoke suppression function according to claim 1, characterized in that: The content of dicyandiamide in the flame retardant finishing liquid is 30-50 g / L.

5. The method for preparing a polyester / cotton blended fabric with durable flame retardancy and smoke suppression function according to claim 4, characterized in that: In the mixed solution, the content of diethylenetriaminepenta(methylenephosphonic acid) is 75-100 g / L, and the content of polyvinyl alcohol is 30-60 g / L.

6. The method for preparing a polyester / cotton blended fabric with durable flame retardancy and smoke suppression function according to claim 5, characterized in that: In the phosphorus / nitrogen / silicon flame retardant solution, the content of tetraethyl orthosilicate is 20-40 g / L.

7. The method for preparing a polyester / cotton blended fabric with durable flame retardancy and smoke suppression function according to claim 6, characterized in that: In the ethanol solution of tetraethyl orthosilicate, the mass ratio of tetraethyl orthosilicate to ethanol is 1-2:

1.

8. The method for preparing a polyester / cotton blended fabric with durable flame retardancy and smoke suppression function according to claim 1, characterized in that: The limiting oxygen index of polyester / cotton blended fabric with long-lasting flame retardancy and smoke suppression is not less than 31.5%, the damaged length is not higher than 8.9cm, and the total amount of smoke released is not higher than 0.48m 2 After 40 washes, the damaged length is still no more than 14.5cm.

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