A method for preparing polyester fabric with layer-by-layer self-assembly and durable flame-retardant coating

Abstract

The invention belongs to the technical field of flame-retardant fabrics, and relates to a method for preparing a polyester fabric with a self-assembled layer-by-layer durable flame-retardant coating, specifically: the polyester fabric is finished by alternating finishing liquid 1 and finishing liquid 2 to form a circulation mode of "finishing liquid 1-finishing liquid 2"; the finishing liquid 1 contains acryloyloxyethyl trimethyl ammonium chloride, epoxy-modified PAMAM, sodium hydroxide and water; the finishing liquid 2 contains phytic acid and water; the finishing process corresponding to the finishing liquid 1 in the first cycle is: impregnation→drying→washing; the finishing process corresponding to the finishing liquid 1 in other cycles is: padding→drying→washing; the finishing process corresponding to the finishing liquid 2 in each cycle is: padding→drying→washing; the impregnation temperature is 70-80°C, and the temperature range of all drying is 70-80°C. The flame-retardant polyester fabric prepared by the method of the invention has good flame retardant properties and excellent flame retardant and water-resistant properties.

Description

Technical Field

[0001] The invention belongs to the technical field of flame-retardant fabrics, and in particular relates to a method for preparing a polyester fabric with a layer-by-layer self-assembled durable flame-retardant coating. Background Art

[0002] Polyester fabrics have excellent mechanical strength, chemical resistance and fatigue resistance, and are widely used in interior decoration, bedding and other fields. However, polyester fabrics are very flammable and have serious melting dripping phenomenon. They are flammable textiles, so it is extremely important to improve the fire safety performance of polyester fabrics.

[0003] The layer-by-layer self-assembly technology mainly deposits flame retardants on the surface of the fabric layer by layer through anionic and cationic electrolytes, thereby improving the flame retardant properties of the fabric. It has the characteristics of high utilization rate and low selectivity to the matrix.

[0004] The literature (Preparation and properties of layer-by-layer self-assembled flame-retardant modified polyester fabrics [J]. Journal of Textile Research, 2019, 40(11): 106-112.) used ultraviolet light irradiation grafting copolymerization technology to graft anionic acrylic acid onto the surface of flame-retardant polyester fabrics, and then used layer-by-layer self-assembly technology to deposit 12 layers of γ-aminopropyltriethoxysilane and sulfobutyl-β-cyclodextrin on the surface of polyester fabric to inhibit the droplet phenomenon of polyester fabric. However, the ionic bonding between the self-assembled coatings is not resistant to water washing.

[0005] Invention patent CN111188192A discloses a flame retardant composition and its application in polyester fabrics. Cationic phosphorus-nitrogen compounds and anionic graphene and polysaccharides are deposited on the surface of polyester fabrics through layer-by-layer self-assembly technology, thereby improving the flame retardant and anti-drip properties of polyester fabrics. However, the ionic bonds between the self-assembled coatings are not resistant to water washing.

[0006] Invention patent CN114908565A discloses a method for preparing a durable flame-retardant polyester fabric. First, the polyester fabric is pretreated with a phenyl-containing long-chain aldehyde to introduce aldehyde groups into the surface of the polyester fabric. Then, cationic polyethyleneimine and anionic sodium polyhexametaphosphate are deposited on the surface of the polyester fabric through layer-by-layer self-assembly, thereby improving the flame retardant properties and washability of the polyester fabric. However, the ionic bond between polyethyleneimine and sodium polyhexametaphosphate is not resistant to washing, and the washability of the coated polyester fabric still needs to be further improved.

[0007] It can be seen that although the layer-by-layer self-assembly technology can improve the flame retardant properties of polyester fabrics, since the coatings are mainly bonded by ionic bonds and cannot be firmly bonded to the polyester fabric, the flame retardant and water-washable properties of the polyester fabrics obtained by the layer-by-layer self-assembly technology are still unsatisfactory. Therefore, it is necessary to further improve the flame retardant and water-washable properties of the polyester fabrics obtained by the layer-by-layer self-assembly technology. Summary of the invention

[0008] The purpose of the invention is to solve the problems existing in the prior art and provide a method for preparing polyester fabric with layer-by-layer self-assembled durable flame-retardant coating.

[0009] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0010] A method for preparing a polyester fabric with a self-assembled layer-by-layer durable flame-retardant coating, wherein the polyester fabric is finished by alternately using a finishing liquid 1 and a finishing liquid 2 to form a "finishing liquid 1-finishing liquid 2" circulation mode;

[0011] Finishing liquid 1 contains acryloyloxyethyl trimethyl ammonium chloride, epoxy-modified PAMAM, sodium hydroxide and water; the polyester fabric has very few active groups and cannot form a strong chemical bond with the self-assembled coating, resulting in poor durability; the addition of sodium hydroxide and acryloyloxyethyl trimethyl ammonium chloride both help to promote the hydrolysis of polyester macromolecular segments on the surface of the polyester fabric, thereby increasing the content of active hydroxyl and carboxyl groups on the surface of the polyester fabric; the addition of sodium hydroxide also helps to promote the dissolution of epoxy-modified PAMAM;

[0012] Epoxy-modified PAMAM is synthesized by the reaction of polyamide-amine dendrimer (PAMAM) and epichlorohydrin. The preparation method is based on the literature (Li Ying, Zhu Ping, Sui Shuying, et al. Epichlorohydrin-modified PAMAM anti-wrinkle finishing of pure cotton fabric [J]. Printing and Dyeing, 2015, 41(3): 6-9);

[0013] Finishing liquid 2 contains phytic acid and water;

[0014] The finishing process corresponding to finishing liquid 1 in the first cycle is: dipping → drying → washing. In this cycle, the higher temperature is conducive to the hydrolysis reaction on the surface of the polyester fabric and promotes the covalent bond grafting of epoxy-modified PAMAM to the polyester fabric; the finishing process corresponding to finishing liquid 1 in other cycles is: padding → drying → washing. In this stage, the epoxy-modified PAMAM in finishing liquid 1 mainly assembles with anionic phytic acid by ionic bonds and covalent bonds, and usually no longer reacts with the polyester fabric; the finishing process corresponding to finishing liquid 2 in each cycle is: padding → drying → washing; washing treatment helps to remove epoxy-modified PAMAM and phytic acid that have not participated in the reaction on the surface, which helps to improve the uniformity and durability of the coating;

[0015] The immersion temperature is 70-80°C, and the drying temperature range is 70-80°C. Such temperature control is conducive to the hydrolysis reaction on the surface of the polyester fabric, and is also conducive to the covalent cross-linking reaction between the epoxy groups of the epoxy-modified PAMAM and the active carboxyl and hydroxyl groups on the surface of the polyester fabric, and is also conducive to the covalent bond between the epoxy groups of the epoxy-modified PAMAM and the phosphate groups of the phytic acid, and is also conducive to the ionic bond between the amino groups of the epoxy-modified PAMAM and the phosphate groups of the phytic acid.

[0016] As the preferred technical solution:

[0017] In the method for preparing the layer-by-layer self-assembled durable flame-retardant coated polyester fabric as described above, the immersion time is 40-60 minutes and the bath ratio is 1:30-40.

[0018] In the method for preparing the layer-by-layer self-assembled durable flame-retardant coated polyester fabric as described above, the drying time ranges from 5 to 10 minutes.

[0019] In the method for preparing the layer-by-layer self-assembled durable flame-retardant coated polyester fabric as described above, all the dipping and rolling are two-dipping and two-rolling, and the rolling rate ranges from 90 to 100%.

[0020] In the method for preparing a layer-by-layer self-assembled durable flame-retardant coated polyester fabric as described above, the number of cycles is 3 to 4. The more the number of cycles, the more flame retardant is deposited on the surface of the polyester fabric, which is more helpful for flame retardancy.

[0021] As described above, in the preparation method of the layer-by-layer self-assembled durable flame-retardant coated polyester fabric, in the finishing liquid 1, the concentration of acryloyloxyethyltrimethylammonium chloride is 0.5~1.5g / L, the concentration of epoxy-modified PAMAM is 20~30g / L, the high concentration of epoxy-modified PAMAM is conducive to deposition on the surface of the polyester fabric, and the concentration of sodium hydroxide is 5~10g / L.

[0022] In the method for preparing the layer-by-layer self-assembled durable flame-retardant coated polyester fabric as described above, the concentration of phytic acid in the finishing liquid 2 is 20-30 g / L. The high concentration of phytic acid is conducive to deposition on the surface of the polyester fabric.

[0023] The method for preparing the polyester fabric with layer-by-layer self-assembled durable flame retardant coating as described above has a limiting oxygen index of not less than 29.5%, a damaged length of not more than 11.9 cm, no molten droplets are generated, and a damaged length of not more than 14.4 cm after 35 times of washing, and has excellent flame retardant properties and water wash resistance.

[0024] Principle of the invention:

[0025] The invention adopts epoxy-modified PAMAM as a cationic component and phytic acid as an anionic component, and prepares a durable flame-retardant coated polyester fabric through layer-by-layer self-assembly treatment.

[0026] During the preparation process, epoxy-modified PAMAM (cationic polymer) and phytic acid (anionic compound) can be deposited on the surface of polyester fabric through ionic bonding; epoxy-modified PAMAM is rich in epoxy groups, which can undergo covalent cross-linking reactions with active carboxyl and hydroxyl groups on the surface of polyester fabric, and can also undergo covalent cross-linking reactions with phosphate groups of phytic acid, thereby improving the durability of the flame retardant coating; therefore, polyester fabric, epoxy-modified PAMAM, and phytic acid can undergo complex cross-linking reactions through ionic and covalent bonding, thereby firmly depositing the self-assembled coating on the surface of polyester fabric, thereby providing a lasting flame retardant function.

[0027] In the final flame-retardant coating, phytic acid is rich in phosphate and epoxy-modified PAMAM is rich in amino. Both can improve the flame retardant properties of polyester fabrics through the synergistic flame retardant mechanism of phosphorus and nitrogen, and have high flame retardant efficiency.

[0028] Beneficial effects:

[0029] (1) In the finishing liquid of the present invention, the epoxy-modified PAMAM is a cationic polymer, which can not only be bonded to the anionic phytic acid through ionic bonds, but also its active epoxy group can be covalently bonded to the phosphate group, thereby improving the durable flame retardant properties of the coated polyester fabric;

[0030] (2) In the finishing liquid of the present invention, phytic acid and epoxy-modified PAMAM are rich in phosphorus and nitrogen groups, and the two improve the flame retardant properties of polyester fabrics through the phosphorus and nitrogen synergistic flame retardant mechanism, and the flame retardant efficiency is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a surface morphology of the coated (after finishing) polyester fabric of Example 1 of the present invention. DETAILED DESCRIPTION

[0032] 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.

[0033] Testing methods for relevant performance indicators:

[0034] Limiting oxygen index: measured by FTT0080 oxygen index meter according to GB / T 5454-1997 standard;

[0035] The damage length is: According to GB / T 5455-2014 standard, the test is carried out using the M233M vertical combustion test machine;

[0036] Damage length after 35 washes: First wash 35 times according to AATCC 61-2013 "Accelerated Test for Color Fastness to Washing for Household and Commercial Use", and then test with M233M vertical burning tester according to GB / T 5455-2014 standard.

[0037] Example 1

[0038] A method for preparing a layer-by-layer self-assembled durable flame-retardant coated polyester fabric, the specific steps are as follows:

[0039] (1) Prepare the raw materials:

[0040] Finishing liquid 1: The components are acryloyloxyethyl trimethyl ammonium chloride, epoxy-modified PAMAM, sodium hydroxide and water; the concentration of acryloyloxyethyl trimethyl ammonium chloride is 0.5 g / L, the concentration of epoxy-modified PAMAM is 20 g / L, and the concentration of sodium hydroxide is 5 g / L;

[0041] Finishing liquid 2: The components are phytic acid and water, and the concentration of phytic acid is 20g / L;

[0042] Polyester fabric: without flame retardant finishing, limiting oxygen index is 18.1%, damaged length is 30cm, and molten droplets are generated;

[0043] (2) Circular arrangement:

[0044] Finishing liquid 1 and finishing liquid 2 are used alternately to finish the polyester fabric, specifically:

[0045] (a) Finishing liquid 1 was used to finish polyester fabric, and the process was: immersion→drying→washing; wherein the immersion time was 60 min, the immersion temperature was 70° C., the bath ratio was 1:30, the drying temperature was 70° C., and the drying time was 10 min;

[0046] (b) using finishing liquid 2 to finish the polyester fabric, the process is: padding → drying → washing; wherein the padding is two-dipping and two-padding, the padding rate is 90%, the drying temperature is 70°C, and the drying time is 10 min;

[0047] (c) using finishing liquid 1 to finish the polyester fabric, the process is: padding → drying → washing; wherein the padding is two-dipping and two-padding, the padding rate is 90%, the drying temperature is 70°C, and the drying time is 10 min;

[0048] (d) using finishing liquid 2 to finish the polyester fabric, the process is: padding → drying → washing; wherein the padding is two-dipping and two-padding, the padding rate is 90%, the drying temperature is 70°C, and the drying time is 10 min;

[0049] (e) Finishing the polyester fabric with finishing liquid 1, the process is: padding→drying→washing; wherein the padding is two-dipping and two-padding, the padding rate is 90%, the drying temperature is 70°C, and the drying time is 10 min;

[0050] (f) Finishing the polyester fabric with finishing liquid 2, the process is: padding → drying → washing; wherein the padding is two-dipping and two-padding, the padding rate is 90%, the drying temperature is 70°C, and the drying time is 10 min;

[0051] After the above finishing steps are completed, the layer-by-layer self-assembled durable flame retardant coated polyester fabric (surface morphology such as Figure 1 as shown).

[0052] The final layer-by-layer self-assembled durable flame-retardant coated polyester fabric had a limiting oxygen index of 29.5%, a damaged length of 11.9 cm, no molten droplets were generated, and the damaged length after 35 washes was 14.4 cm.

[0053] Comparative Example 1

[0054] A method for preparing a flame retardant coated polyester fabric is basically the same as that in Example 1, except that there is no epoxy-modified PAMAM in this comparative example, and other conditions remain unchanged.

[0055] The final flame-retardant coated polyester fabric had a limiting oxygen index of 27.3%, a damaged length of 12.5 cm, no molten droplets were generated, and a damaged length of 30 cm after 35 washes.

[0056] Compared with Example 1, the flame retardant and water washability of the flame retardant coated polyester fabric prepared in Comparative Example 1 is significantly reduced. This is because Comparative Example 1 does not have epoxy-modified PAMAM, and only uses phytic acid to modify the polyester fabric. However, phytic acid and polyester fabric cannot form a strong bond, resulting in poor flame retardant and water washability.

[0057] Comparative Example 2

[0058] A method for preparing a flame-retardant coated polyester fabric is basically the same as that in Example 1, except that PAMAM (Chinese medicine code XW0115577372102, Sinopharm Chemical Reagent Co., Ltd.) is used in this comparative example to replace the epoxy-modified PAMAM in the original Example 1, and other conditions remain unchanged.

[0059] The final flame-retardant coated polyester fabric had a limiting oxygen index of 29.0%, a damaged length of 12.2 cm, no molten droplets were generated, and a damaged length of 30 cm after 35 times of washing.

[0060] Compared with Example 1, the flame retardant and water-washing resistance of the flame-retardant coated polyester fabric prepared in Comparative Example 2 is significantly reduced. This is because when the PAMAM and phytic acid used in Comparative Example 2 are assembled layer by layer to modify the polyester fabric, the two components are only bonded by ionic bonds and cannot form a strong bond with the polyester fabric, resulting in reduced flame retardant and water-washing resistance.

[0061] Comparative Example 3

[0062] A method for preparing a flame retardant coated polyester fabric is basically the same as that in Example 1, except that 1,2,3,4-butanetetracarboxylic acid is used in this comparative example to replace the epoxy-modified PAMAM in the original Example 1, and other conditions remain unchanged.

[0063] The final flame-retardant coated polyester fabric had a limiting oxygen index of 27.8%, a damaged length of 12.4 cm, no molten droplets were generated, and a damaged length of 30 cm after 35 washes.

[0064] Compared with Example 1, the flame retardant and water washability of the flame retardant coated polyester fabric prepared in Comparative Example 3 is significantly reduced. This is because the cross-linking agent 1,2,3,4-butanetetracarboxylic acid used in Comparative Example 3 cannot be cross-linked with the polyester fiber and cannot be combined with phytic acid.

[0065] Comparative Example 4

[0066] A method for preparing a flame-retardant coated polyester fabric is basically the same as that of Example 1, except that acryloyloxyethyl trimethyl ammonium chloride is not added to the finishing liquid 1.

[0067] The final flame-retardant coated polyester fabric had a limiting oxygen index of 28.4%, a damaged length of 12.3 cm, no molten droplets were generated, and the damaged length was 30 cm after 35 washes.

[0068] Compared with Example 1, the flame retardant and water-washing resistance of the flame-retardant coated polyester fabric prepared in Comparative Example 4 is significantly reduced. This is because Comparative Example 4 does not use the accelerator acryloyloxyethyltrimethylammonium chloride, and the degree of hydrolysis of the polyester macromolecular segments on the surface of the polyester fabric is relatively small, resulting in a lower content of active hydroxyl and carboxyl groups on the surface of the polyester fabric, making it difficult for the flame retardant coating to form a good bond with the polyester fabric.

[0069] Example 2

[0070] A method for preparing a layer-by-layer self-assembled durable flame-retardant coated polyester fabric, the specific steps are as follows:

[0071] (1) Prepare the raw materials:

[0072] Finishing liquid 1: The components are acryloyloxyethyl trimethyl ammonium chloride, epoxy-modified PAMAM, sodium hydroxide and water; the concentration of acryloyloxyethyl trimethyl ammonium chloride is 1 g / L, the concentration of epoxy-modified PAMAM is 23 g / L, and the concentration of sodium hydroxide is 7 g / L;

[0073] Finishing liquid 2: The components are phytic acid and water, and the concentration of phytic acid is 23g / L;

[0074] Polyester fabric: without flame retardant finishing, limiting oxygen index is 18.1%, damaged length is 30cm, and molten droplets are generated;

[0075] (2) Circular arrangement:

[0076] Finishing liquid 1 and finishing liquid 2 are used alternately to finish the polyester fabric, specifically:

[0077] (a) Finishing liquid 1 was used to finish polyester fabric, and the process was: immersion→drying→washing; wherein the immersion time was 65 min, the immersion temperature was 74° C., the bath ratio was 1:35, the drying temperature was 75° C., and the drying time was 7 min;

[0078] (b) Finishing the polyester fabric with finishing liquid 2, the process is: padding → drying → washing; wherein the padding is two-dipping and two-padding, the padding rate is 95%, the drying temperature is 73°C, and the drying time is 8 min;

[0079] (c) using finishing liquid 1 to finish the polyester fabric, the process is: padding → drying → washing; wherein the padding is two-dipping and two-padding, the padding rate is 95%, the drying temperature is 73°C, and the drying time is 8 min;

[0080] (d) Finishing the polyester fabric with finishing liquid 2, the process is: padding → drying → washing; wherein the padding is two-dipping and two-padding, the padding rate is 95%, the drying temperature is 73°C, and the drying time is 8 min;

[0081] (e) Finishing the polyester fabric with finishing liquid 1, the process is: padding→drying→washing; wherein the padding is two-dipping and two-padding, the padding rate is 95%, the drying temperature is 73°C, and the drying time is 8 min;

[0082] (f) Finishing the polyester fabric with finishing liquid 2, the process is: padding → drying → washing; wherein the padding is two-dipping and two-padding, the padding rate is 95%, the drying temperature is 73°C, and the drying time is 8 min;

[0083] After the above finishing steps are completed, the layer-by-layer self-assembled durable flame retardant coated polyester fabric is obtained.

[0084] The final layer-by-layer self-assembled durable flame-retardant coated polyester fabric had a limiting oxygen index of 30.7%, a damaged length of 10.8 cm, no melt droplets were generated, and the damaged length after 35 washes was 13.9 cm.

[0085] Example 3

[0086] A method for preparing a layer-by-layer self-assembled durable flame-retardant coated polyester fabric, the specific steps are as follows:

[0087] (1) Prepare the raw materials:

[0088] Finishing liquid 1: The components are acryloyloxyethyl trimethyl ammonium chloride, epoxy-modified PAMAM, sodium hydroxide and water; the concentration of acryloyloxyethyl trimethyl ammonium chloride is 1.3 g / L, the concentration of epoxy-modified PAMAM is 26 g / L, and the concentration of sodium hydroxide is 9 g / L;

[0089] Finishing liquid 2: The components are phytic acid and water, and the concentration of phytic acid is 26g / L;

[0090] Polyester fabric: without flame retardant finishing, limiting oxygen index is 18.1%, damaged length is 30cm, and molten droplets are generated;

[0091] (2) Circular arrangement:

[0092] Finishing liquid 1 and finishing liquid 2 are used alternately to finish the polyester fabric, specifically:

[0093] (a) Finishing liquid 1 was used to finish polyester fabric, and the process was: immersion→drying→washing; wherein the immersion time was 50 min, the immersion temperature was 77° C., the bath ratio was 1:40, the drying temperature was 80° C., and the drying time was 5 min;

[0094] (b) using finishing liquid 2 to finish the polyester fabric, the process is: padding → drying → washing; wherein the padding is two-dipping and two-padding, the padding rate is 100%, the drying temperature is 76°C, and the drying time is 6 min;

[0095] (c) using finishing liquid 1 to finish the polyester fabric, the process is: padding → drying → washing; wherein the padding is two-dipping and two-padding, the padding rate is 100%, the drying temperature is 76°C, and the drying time is 6 min;

[0096] (d) Finishing the polyester fabric with finishing liquid 2, the process is: padding → drying → washing; wherein the padding is two-dipping and two-padding, the padding rate is 100%, the drying temperature is 76°C, and the drying time is 6 min;

[0097] (e) Finishing the polyester fabric with finishing liquid 1, the process is: padding→drying→washing; wherein the padding is two-dipping and two-padding, the padding rate is 100%, the drying temperature is 76°C, and the drying time is 6 min;

[0098] (f) Finishing the polyester fabric with finishing liquid 2, the process is: padding → drying → washing; wherein the padding is two-dipping and two-padding, the padding rate is 100%, the drying temperature is 76°C, and the drying time is 6 min;

[0099] (g) using finishing liquid 1 to finish the polyester fabric, the process is: padding → drying → washing; wherein the padding is two-dipping and two-padding, the padding rate is 100%, the drying temperature is 76°C, and the drying time is 6 min;

[0100] (h) using finishing liquid 2 to finish the polyester fabric, the process is: padding → drying → washing; wherein the padding is two-dipping and two-padding, the padding rate is 100%, the drying temperature is 76°C, and the drying time is 6 min;

[0101] After the above finishing steps are completed, the layer-by-layer self-assembled durable flame retardant coated polyester fabric is obtained.

[0102] The final layer-by-layer self-assembled durable flame-retardant coated polyester fabric had a limiting oxygen index of 31.4%, a damaged length of 10 cm, no molten droplets were generated, and the damaged length after 35 washes was 13.5 cm.

[0103] Example 4

[0104] A method for preparing a layer-by-layer self-assembled durable flame-retardant coated polyester fabric, the specific steps are as follows:

[0105] (1) Prepare the raw materials:

[0106] Finishing liquid 1: The components are acryloyloxyethyl trimethyl ammonium chloride, epoxy-modified PAMAM, sodium hydroxide and water; the concentration of acryloyloxyethyl trimethyl ammonium chloride is 1.5 g / L, the concentration of epoxy-modified PAMAM is 30 g / L, and the concentration of sodium hydroxide is 10 g / L;

[0107] Finishing liquid 2: The components are phytic acid and water, and the concentration of phytic acid is 30g / L;

[0108] Polyester fabric: without flame retardant finishing, limiting oxygen index is 18.1%, damaged length is 30cm, and molten droplets are generated;

[0109] (2) Circular arrangement:

[0110] Finishing liquid 1 and finishing liquid 2 are used alternately to finish the polyester fabric, specifically:

[0111] (a) Finishing liquid 1 was used to finish polyester fabric, and the process was: immersion→drying→washing; wherein the immersion time was 40 min, the immersion temperature was 80° C., the bath ratio was 1:35, the drying temperature was 75° C., and the drying time was 8 min;

[0112] (b) using finishing liquid 2 to finish the polyester fabric, the process is: padding → drying → washing; wherein the padding is two-dipping and two-padding, the padding rate is 95%, the drying temperature is 80°C, and the drying time is 5 min;

[0113] (c) using finishing liquid 1 to finish the polyester fabric, the process is: padding → drying → washing; wherein the padding is two-dipping and two-padding, the padding rate is 95%, the drying temperature is 80°C, and the drying time is 5 min;

[0114] (d) using finishing liquid 2 to finish the polyester fabric, the process is: padding → drying → washing; wherein the padding is two-dipping and two-padding, the padding rate is 95%, the drying temperature is 80°C, and the drying time is 5 min;

[0115] (e) Finishing the polyester fabric with finishing liquid 1, the process is: padding→drying→washing; wherein the padding is two-dipping and two-padding, the padding rate is 95%, the drying temperature is 80°C, and the drying time is 5 min;

[0116] (f) Finishing the polyester fabric with finishing liquid 2, the process is: padding → drying → washing; wherein the padding is two-dipping and two-padding, the padding rate is 95%, the drying temperature is 80°C, and the drying time is 5 min;

[0117] (g) using finishing liquid 1 to finish the polyester fabric, the process is: padding → drying → washing; wherein the padding is two-dipping and two-padding, the padding rate is 95%, the drying temperature is 80°C, and the drying time is 5 min;

[0118] (h) using finishing liquid 2 to finish the polyester fabric, the process is: padding → drying → washing; wherein the padding is two-dipping and two-padding, the padding rate is 95%, the drying temperature is 80°C, and the drying time is 5 min;

[0119] After the above finishing steps are completed, the layer-by-layer self-assembled durable flame retardant coated polyester fabric is obtained.

[0120] The final layer-by-layer self-assembled durable flame-retardant coated polyester fabric had a limiting oxygen index of 32%, a damaged length of 9.2 cm, no melt droplets were generated, and the damaged length after 35 washes was 13.1 cm.

Claims

1. A method for preparing a layer-by-layer self-assembled durable flame-retardant coated polyester fabric, characterized in that: The polyester fabric is finished by using the finishing liquid 1 and the finishing liquid 2 alternately, forming a "finishing liquid 1-finishing liquid 2" circulation mode; The finishing liquid 1 contains acryloyloxyethyl trimethyl ammonium chloride, epoxy-modified PAMAM, sodium hydroxide and water; in the finishing liquid 1, the concentration of acryloyloxyethyl trimethyl ammonium chloride is 0.5-1.5 g / L, the concentration of epoxy-modified PAMAM is 20-30 g / L, and the concentration of sodium hydroxide is 5-10 g / L; Finishing liquid 2 contains phytic acid and water; The finishing process corresponding to finishing liquid 1 in the first cycle is: dipping → drying → washing; the finishing process corresponding to finishing liquid 1 in other cycles is: padding → drying → washing; the finishing process corresponding to finishing liquid 2 in each cycle is: padding → drying → washing; The dipping temperature is 70-80°C, and all drying temperatures are in the range of 70-80°C.

2. The method for preparing a polyester fabric with a layer-by-layer self-assembled durable flame-retardant coating according to claim 1, characterized in that: The immersion time is 40 to 60 minutes, and the bath ratio is 1:30 to 40.

3. The method for preparing a polyester fabric with layer-by-layer self-assembled durable flame-retardant coating according to claim 1, characterized in that: All drying times range from 5 to 10 minutes.

4. The method for preparing a polyester fabric with a layer-by-layer self-assembled durable flame-retardant coating according to claim 1, characterized in that: All the dipping and rolling processes are double dipping and double rolling, and the rolling ratio ranges from 90 to 100%.

5. The method for preparing a polyester fabric with a layer-by-layer self-assembled durable flame-retardant coating according to claim 1, characterized in that: The number of cycles is 3 to 4.

6. The method for preparing a polyester fabric with a layer-by-layer self-assembled durable flame-retardant coating according to claim 1, characterized in that: In the finishing solution 2, the concentration of phytic acid is 20 to 30 g / L.

7. The method for preparing a polyester fabric with a layer-by-layer self-assembled durable flame-retardant coating according to any one of claims 1 to 6, characterized in that: The limiting oxygen index of the layer-by-layer self-assembled durable flame-retardant coated polyester fabric is not less than 29.5%, the damaged length is not higher than 11.9 cm, no molten droplets are generated, and the damaged length after 35 times of washing is not higher than 14.4 cm.

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