Flame-retardant functional fabric, and preparation method and application thereof

Abstract

The application belongs to the technical field of textiles and relates to a flame-retardant functional fabric as well as a preparation method and application thereof. The flame-retardant functional fabric is obtained by sequentially subjecting a base cloth to padding treatment in a flame-retardant finishing liquid, a cross-linking and curing finishing liquid and a hydrophilic soft finishing liquid. The flame-retardant finishing liquid comprises modified epoxy triazine resin flame retardant and water. The cross-linking and curing finishing liquid comprises modified polycarboxylic acid cross-linking agent, reducing agent and water. The hydrophilic soft finishing liquid comprises modified polyether silicone oil hydrophilic softener and water. By limiting the composition of the flame-retardant finishing liquid, the cross-linking and curing finishing liquid and the hydrophilic soft finishing liquid, the flame-retardant functional fabric obtained finally has the advantages of long-lasting flame-retardant performance, excellent moisture absorption and air permeability, excellent washing resistance and soft hand feeling, and meets the use requirements of welding protective clothing fabric.

Description

Technical Field

[0001] This invention belongs to the field of textile technology and relates to a flame-retardant functional fabric, its preparation method, and its application. Background Technology

[0002] With the rapid development of fire protection, metallurgy, welding, and special industrial protection fields, the demand for high-performance flame-retardant protective fabrics is becoming increasingly urgent. An ideal flame-retardant fabric not only needs to have excellent and durable flame-retardant properties, but also needs to take into account good wearing comfort, including a soft hand feel and excellent hydrophilicity and breathability, to meet the personnel protection needs in high-temperature and high-risk working environments.

[0003] Currently, most finishing techniques for flame-retardant fabrics employ a pad-drying process, where the selection and application of flame retardants, crosslinking agents, and softeners are crucial in determining fabric performance. However, existing technologies generally suffer from the following bottlenecks: First, the flame retardancy and durability are insufficient. Most of the flame retardants widely used in existing technologies are additive or semi-durable types, which mainly rely on van der Waals forces or hydrogen bonds to physically adsorb onto the fiber surface, lacking stable chemical bonds with fiber macromolecules. This physical bonding force is weak, and during the washing process, the flame retardant is very easy to fall off the fiber, causing the flame retardant performance of the fabric to drop sharply with the number of washes, making it difficult to meet the long-term washability standards for protective clothing.

[0004] Secondly, there is the conflict between feel and comfort. To solve the problem of flame retardant fixation, cross-linking agents are usually introduced to enhance the adhesion between the coating and the fiber. However, traditional cross-linking agents (such as amino resins) have strong molecular rigidity and high hardness after cross-linking and film formation, resulting in a rough, stiff, and rigid feel in the finished fabric, which seriously affects the drape and wearing comfort of the fabric. In addition, in order to balance protection and thermal and moisture comfort, hydrophilic finishing agents are often used in the industry, but traditional amino silicone oil softeners have extremely poor hydrophilicity, resulting in poor breathability and moisture permeability of the finished fabric, making it stuffy to wear. Although commercially available hydrophilic modified silicone oils introduce hydrophilic groups, they generally have the problem of weak adhesion between the hydrophilic segments and the silicone oil main chain, resulting in poor wash resistance. After several washes, the hydrophilicity and soft feel are greatly reduced.

[0005] Secondly, there is the issue of compatibility with composite functional finishing. To address the aforementioned shortcomings, patent CN109137510A discloses a welding protective clothing fabric based on superabsorbent grafted materials and its preparation method. This method involves applying a water-repellent finishing agent to the reverse side of a flame-retardant fabric and spraying a solution containing a vinyl hydrophilic monomer, a crosslinking agent, and a polymerization inhibitor onto the front side. Superabsorbent polymers are then formed on the fiber surface through ionizing radiation grafting technology. While this technology improves the fabric's heat insulation and burn-proof properties and wearing comfort to some extent, it still has significant limitations: First, the flame retardant used in this solution is still a conventional additive flame retardant, failing to solve the fundamental problem of chemical bonding between the flame retardant and the fiber, resulting in questionable wash resistance. Second, the crosslinking agent used still suffers from strong molecular rigidity, and the problem of a rough and stiff fabric feel after the crosslinking reaction is not effectively improved. Third, this solution focuses on grafting modification and does not specifically optimize the softener system; the inherent problems of poor hydrophilicity or insufficient wash resistance of traditional softeners remain, failing to fundamentally improve the overall performance of the fabric.

[0006] Therefore, developing a flame-retardant functional fabric that achieves strong bonding between flame retardants and fibers, has a soft and hydrophilic feel, and possesses excellent washability is a technical challenge that urgently needs to be solved in this field. Summary of the Invention

[0007] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a flame-retardant functional fabric, its preparation method and application, wherein the flame-retardant functional fabric has long-lasting flame-retardant properties, excellent moisture absorption and breathability, excellent water resistance and soft hand feel.

[0008] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides a flame-retardant functional fabric, which is obtained by sequentially padding a base fabric in a flame-retardant finishing liquid, a cross-linking curing finishing liquid and a hydrophilic softening finishing liquid. The flame-retardant finishing liquid comprises a modified epoxy triazine resin flame retardant and water. The raw materials of the modified epoxy triazine resin flame retardant include hexafluorocyclotriazine nitrile, phenol, ammonium naphthalene sulfonate, polyethylene glycol monomethyl ether, and allyl alcohol. The crosslinking curing finishing liquid includes a modified polycarboxylic acid crosslinking agent, a reducing agent, and water. The raw materials for the modified polycarboxylic acid crosslinking agent include butene tetracarboxylic acid, polyethylene glycol, itaconic acid, and citric acid. The hydrophilic softening finishing liquid comprises a modified polyether silicone oil hydrophilic softener and water. The raw materials of the modified polyether silicone oil hydrophilic softener include nitrogen-containing silicone oil, alkylpropyl polyoxyethylene ether, 1-dodecylimidazolium and vinyltrimethoxysilane.

[0009] The flame-retardant functional fabric provided by this invention is obtained by sequentially padding a base fabric in a flame-retardant finishing liquid, a cross-linking curing finishing liquid, and a hydrophilic softening finishing liquid. First, the flame-retardant finishing liquid comprises a modified epoxy triazine resin flame retardant and water. The modified epoxy triazine resin flame retardant uses hexafluorocyclotriazine nitrile as its backbone, and introduces phenoxy and ammonium sulfonate groups through phenol and ammonium naphthalene sulfonate substitution, respectively. The phenoxy groups impart a synergistic flame-retardant effect of phosphorus and nitrogen, improving its char formation rate and thermal stability. The ammonium naphthalene sulfonate enhances its interfacial bonding force with fibers, solving the problems of insufficient affinity between traditional phosphorus and nitrogen-based flame retardants and the attenuation of flame-retardant effect with washing. Polyethylene glycol monomethyl ether grafting introduces hydrophilic polyether segments, improving the flame-retardant effect... The dispersion stability of the flame retardant in the aqueous phase avoids the defects of conventional flame retardants, such as easy agglomeration and poor finishing uniformity. Allyl alcohol end-capping introduces active unsaturated double bonds, enabling the flame retardant to chemically bond with the crosslinking agent and fibers under high-temperature conditions, achieving durable flame retardancy, unlike existing additive flame retardants that rely solely on physical adsorption. Secondly, the crosslinking curing finishing liquid includes a modified polycarboxylic acid crosslinking agent, a reducing agent, and water. The modified polycarboxylic acid crosslinking agent is based on butene tetracarboxylic acid, and flexible polyether segments are embedded in its rigid molecular chain through polyethylene glycol internal plasticization and esterification, effectively alleviating the rough and stiff feel and poor drape of fabrics after conventional butene tetracarboxylic acid crosslinking, while retaining high crosslinking activity. Itaconic acid copolymerization... The addition of extra carboxyl groups and double bonds increases the crosslinking density and active reaction sites, significantly improving the bonding strength between the flame retardant and the fiber, overcoming the limited crosslinking efficiency of existing single-component crosslinking agents. Citric acid, through its multi-carboxyl structure, forms hydrogen and ester bonds with butenetetracarboxylic acid, ensuring crosslinking effectiveness while reducing dependence on expensive butenetetracarboxylic acid, thus lowering raw material costs. Furthermore, the weak acid buffering effect of citric acid prevents excessive damage to fiber strength caused by the strong acidity of a single butenetetracarboxylic acid system. Finally, the hydrophilic softening finishing liquid comprises a modified polyether silicone oil hydrophilic softener and water. The modified polyether silicone oil hydrophilic softener has a nitrogen-containing silicone oil as its main chain, which is hydrosilylated via alkylpropyl polyoxyethylene ether. The introduction of hydrophilic polyether segments into the branch imparts permanent hydrophilicity to the silicone oil, solving the problem of hydrophobicity and stuffiness associated with traditional amino silicone oils. This results in fabrics that are both soft to the touch and have excellent moisture absorption and breathability. The 1-dodecyl imidazole modification precisely controls the hydrophilic and lipophilic balance through the introduction of long-chain alkyl groups, avoiding the decrease in wash resistance caused by excessive hydrophilicity. At the same time, the imidazole group imparts certain antibacterial functions, which is different from the common problem of weak hydrophilic segment bonding and drastic performance drop after multiple washes in commercially available hydrophilic silicone oils. The introduction of active silane groups by vinyltrimethoxysilane end-capping enables the softener to form covalent bonds with the fiber and crosslinking agent system during the baking process, achieving durable fixation of the softening function rather than simple physical coating.

[0010] In summary, by sequentially impregnating the base fabric with flame-retardant finishing liquid, cross-linking curing finishing liquid, and hydrophilic softening finishing liquid, the final fabric possesses durable flame-retardant properties, excellent moisture absorption and breathability, superior washability, and a soft hand feel, thus meeting the usage requirements of welding protective clothing fabrics.

[0011] Preferably, the modified epoxy triazine resin flame retardant in the flame retardant finishing liquid has a mass percentage of 4-10%, such as 4%, 5%, 6%, 7%, 8%, 9%, or 10%.

[0012] Preferably, the modified epoxy triazine resin flame retardant is prepared by the following method, which includes the following steps: (A1) Dissolve hexafluorocyclotriazine nitrile in acetone, add phenol and ammonium naphthalenesulfonate to react and obtain phenoxy-substituted epoxytriazine intermediate; (A2) The phenoxy-substituted triazine oxide intermediate obtained in step (A1) is reacted with polyethylene glycol monomethyl ether to obtain a hydrophilic grafted modified product. (A3) React the hydrophilic grafted modified product obtained in step (A2) with allyl alcohol, remove the solvent, and obtain the modified epoxy triazine resin flame retardant.

[0013] Preferably, the molar ratio of hexafluorocyclotriazine nitrile and phenol in step (A1) is 1:(3~4), such as 1:3, 1:3.2, 1:3.4, 1:3.6, 1:3.8 or 1:4, etc.

[0014] Preferably, the mass of ammonium naphthalenesulfonate in step (A1) is 3 to 5% of the mass of phenol, such as 3.1%, 3.3%, 3.5%, 3.7%, 3.9% or 4%.

[0015] Preferably, the reaction temperature in step (A1) is 40~60℃, for example 40℃, 42℃, 44℃, 46℃, 48℃, 50℃, 52℃, 54℃, 56℃, 58℃ or 60℃.

[0016] Preferably, the reaction time in step (A1) is 4 to 6 hours, for example, 4.1 hours, 4.3 hours, 4.5 hours, 5 hours, 5.5 hours or 6 hours.

[0017] Preferably, the molar ratio of polyethylene glycol monomethyl ether and hexafluorocyclotriazine nitrile in step (A2) is 1:(1~1.5), such as 1:1, 1:1.1, 1:1.2, 1:1.3 or 1:1.5.

[0018] Preferably, the number average molecular weight of the polyethylene glycol monomethyl ether in step (A2) is 200 to 400, such as 200, 220, 240, 260, 280, 300, 320, 340, 360, 380 or 400.

[0019] Preferably, the reaction temperature in step (A2) is 60~80℃, such as 61℃, 63℃, 65℃, 70℃, 72℃, 74℃, 76℃, 78℃ or 80℃.

[0020] Preferably, the reaction time in step (A2) is 3 to 5 hours, for example, 3.1 hours, 3.3 hours, 3.5 hours, 4 hours, 4.2 hours, 4.4 hours, 4.6 hours, 4.8 hours, or 5 hours.

[0021] Preferably, the molar ratio of allyl alcohol and hexafluorocyclotriazine nitrile in step (A3) is (0.6~1):1, for example, 0.6:1, 0.7:1, 0.8:1 or 0.9:1, etc.

[0022] Preferably, the reaction temperature in step (A3) is 50~70°C, for example 51°C, 53°C, 55°C, 60°C, 62°C, 64°C, 66°C, 68°C or 70°C, etc.

[0023] Preferably, the reaction time in step (A3) is 2 to 4 hours, such as 2.1 hours, 2.3 hours, 2.5 hours, 2.7 hours, 3 hours, 3.2 hours, 3.4 hours, 3.6 hours, 3.8 hours, or 4 hours, etc.

[0024] Preferably, the modified polycarboxylic acid crosslinking agent in the crosslinking curing finishing liquid has a mass percentage content of 5-12%, such as 5%, 6%, 7%, 8%, 9%, 10%, or 12%.

[0025] Preferably, the modified polycarboxylic acid crosslinking agent is prepared by the following method, which includes the following steps: (B1) Butene tetracarboxylic acid is dissolved in water and polyethylene glycol is added to react, resulting in an internally plasticized esterified product; (B2) React the internally plasticized esterified product obtained in step (B1) with itaconic acid to obtain an intermediate product; (B3) The intermediate product obtained in step (B2) is reacted with citric acid to obtain the modified polycarboxylic acid crosslinking agent.

[0026] Preferably, the molar ratio of polyethylene glycol and polyenetetracarboxylic acid in step (B1) is 1:(5~8), such as 1:5, 1:5.2, 1:5.5, 1:5.8, 1:6, 1:6.2, 1:6.5, 1:7, 1:7.4, 1:7.6 or 1:8, etc.

[0027] Preferably, the reaction temperature in step (B1) is 80~95℃, such as 81℃, 83℃, 85℃, 90℃, 92℃, 94℃ or 95℃.

[0028] Preferably, the reaction time in step (B1) is 1 to 2 hours, such as 1.1 hours, 1.3 hours, 1.5 hours, 1.7 hours, 1.9 hours, or 2 hours.

[0029] Preferably, the molar ratio of itaconic acid and butenetetracarboxylic acid in step (B2) is 1:(3~5), such as 1:3, 1:3.2, 1:3.5, 1:3.8, 1:4, 1:4.2, 1:4.4, 1:4.6, 1:4.8 or 1:5, etc.

[0030] Preferably, the reaction temperature in step (B2) is 75~85°C, for example 76°C, 78°C, 80°C, 82°C, 84°C or 85°C.

[0031] Preferably, the reaction time in step (B2) is 40 to 60 minutes, such as 40 minutes, 42 minutes, 45 minutes, 48 ​​minutes, 50 minutes, 52 minutes, 54 minutes, 56 minutes, 58 minutes, or 60 minutes.

[0032] Preferably, the molar ratio of citric acid and butenetetracarboxylic acid in step (B3) is 1:(6~10), such as 1:6, 1:6.5, 1:7, 1:7.5, 1:8, 1:8.5, 1:9, 1:9.5 or 1:10.

[0033] Preferably, the reaction temperature in step (B3) is 60~70°C, for example 61°C, 63°C, 65°C, 67°C, 69°C or 70°C.

[0034] Preferably, the reaction time in step (B3) is 30 to 50 minutes, such as 30 minutes, 32 minutes, 34 minutes, 36 minutes, 38 minutes, 40 minutes, 42 minutes, 44 minutes, 46 minutes, 48 ​​minutes, or 50 minutes.

[0035] Preferably, the mass percentage of the reducing agent in the crosslinking curing finishing liquid is 0.2-0.6%, such as 0.2%, 0.3%, 0.4%, 0.5% or 0.6%.

[0036] Preferably, the reducing agent includes any one or a combination of at least two of sodium hypophosphite, sodium phosphite, and sodium dihydrogen phosphate.

[0037] Preferably, the modified polyether silicone oil hydrophilic softener in the hydrophilic softening finishing liquid has a mass percentage content of 2-6%, such as 1%, 1.2%, 1.4%, 1.6%, 1.8%, 2%, 2.2%, 2.4%, 2.6%, 2.8%, or 3%.

[0038] Preferably, the modified polyether silicone oil hydrophilic softener is prepared by the following method, which includes the following steps: (C1) Nitrogen-containing silicone oil is dissolved in isopropanol, and alkylpropyl polyoxyethylene ether and catalyst are added to react and obtain polyether-grafted silicone oil. (C2) The polyether-grafted silicone oil obtained in step (C1) is reacted with 1-dodecylimidazolium to obtain an imidazolium-modified product; (C3) The imidazole-modified product obtained in step (C2) is reacted with vinyltrimethoxysilane to obtain the modified polyether silicone oil hydrophilic softener.

[0039] Preferably, the nitrogen content in the nitrogen-containing silicone oil in step (C1) is 0.1-0.3% by mass, such as 0.1%, 0.15%, 0.2%, 0.25% or 0.3%.

[0040] Preferably, the molar ratio of Si-H in the alkylpropyl polyoxyethylene ether and nitrogen-containing silicone oil in step (C1) is (0.6~0.8):1, for example, 0.6:1, 0.65:1, 0.7:1, 0.75:1 or 0.8:1, etc.

[0041] Preferably, the catalyst in step (C1) comprises chloroplatinic acid.

[0042] Preferably, the mass ratio of the catalyst in step (C1) is 0.003 to 0.005% of the mass of the nitrogen-containing silicone oil, such as 0.003%, 0.0035%, 0.004%, 0.0045%, or 0.005%.

[0043] Preferably, the reaction temperature in step (C1) is 80~100℃, such as 81℃, 83℃, 85℃, 87℃, 89℃, 91℃, 93℃, 95℃, 97℃ or 100℃.

[0044] Preferably, the reaction time in step (C1) is 4 to 6 hours, for example, 4 hours, 4.5 hours, 5 hours, 5.5 hours or 6 hours.

[0045] Preferably, the molar ratio of the remaining Si-H in the nitrogen-containing silicone oil after the hydrosilylation reaction of 1-dodecylimidazol in step (C2) is (0.1~0.3):1, for example 0.11:1, 0.13:1, 0.15:1, 0.17:1, 0.19:1, 0.21:1, 0.23:1, 0.25:1 or 0.29:1, etc.

[0046] Preferably, the reaction temperature in step (C2) is 90~110℃, such as 91℃, 93℃, 95℃, 100℃, 105℃ or 110℃.

[0047] Preferably, the reaction time in step (C2) is 2 to 3 hours, such as 2.1 hours, 2.3 hours, 2.5 hours, 2.7 hours, 2.9 hours, or 3 hours.

[0048] Preferably, the molar ratio of vinyltrimethoxysilane to the final remaining Si-H in the nitrogen-containing silicone oil in step (C3) is (0.6~1):1, for example, 0.6:1, 0.65:1, 0.7:1, 0.75:1, 0.8:1, 0.85:1 or 0.9:1, etc.

[0049] Preferably, the reaction temperature in step (C3) is 60~70°C, for example 61°C, 63°C, 65°C, 67°C, 69°C or 70°C.

[0050] Preferably, the reaction time in step (C3) is 1 to 2 hours, such as 1.1 hours, 1.3 hours, 1.5 hours, 1.7 hours, 1.9 hours, or 2 hours.

[0051] In a second aspect, the present invention provides a method for preparing a flame-retardant functional fabric as described in the first aspect, the method comprising the following steps: (1) Flame retardant finishing: The base fabric is dipped and rubbed twice in the flame retardant finishing solution and then dried to obtain the flame retardant finished fabric. (2) Cross-linking and fixing: The flame-retardant finished fabric is dipped and rubbed twice in the cross-linking curing solution and then dried to obtain the cross-linked and fixed fabric. (3) Hydrophilic softening finishing: The cross-linked and fixed fabric is dipped and rolled twice in a hydrophilic softening finishing solution, and then dried and shaped to obtain the flame-retardant functional fabric.

[0052] Preferably, the residual rate after two dips and two rolls in step (1) is 75-90%, such as 75%, 76%, 78%, 80%, 82%, 84%, 86%, 88%, or 90%.

[0053] Preferably, the drying temperature in step (1) is 80~100℃, such as 81℃, 83℃, 85℃, 87℃, 89℃, 91℃, 93℃, 95℃, 99℃ or 100℃.

[0054] Preferably, the drying time in step (1) is 1 to 3 min, for example 1.1 min, 1.3 min, 1.5 min, 1.7 min, 1.9 min, 2.1 min, 2.3 min, 2.5 min, 2.7 min or 2.9 min.

[0055] Preferably, the residual rate after two dips and two rolls in step (2) is 70-85%, such as 71%, 73%, 75%, 77%, 79%, 81%, 83% or 85%.

[0056] Preferably, the drying temperature in step (2) is 160~180℃, such as 161℃, 163℃, 165℃, 167℃, 169℃, 171℃, 175℃, 178℃ or 180℃.

[0057] Preferably, the drying time in step (2) is 3 to 5 minutes, such as 3 minutes, 3.5 minutes, 4 minutes, 4.2 minutes, 4.4 minutes, 4.6 minutes, 4.8 minutes or 5 minutes.

[0058] Preferably, the residual rate after two dips and two rolls in step (3) is 65-80%, such as 66%, 68%, 70%, 72%, 74%, 76%, 78% or 80%.

[0059] Preferably, the drying and shaping temperature in step (2) is 120~150℃, such as 120℃, 125℃, 130℃, 135℃, 140℃, 145℃ or 150℃.

[0060] Preferably, the drying and shaping time in step (2) is 4 to 6 minutes, for example, 4 minutes, 4.5 minutes, 5 minutes, 5.5 minutes, or 6 minutes.

[0061] Thirdly, the present invention provides a welding protective suit, the welding protective suit comprising the flame-retardant functional fabric as described in the first aspect.

[0062] Compared with the prior art, the present invention has the following beneficial effects: The flame-retardant functional fabric provided by this invention is obtained by sequentially padding a base fabric in a flame-retardant finishing liquid, a cross-linking curing finishing liquid, and a hydrophilic softening finishing liquid. By limiting the composition of the flame-retardant finishing liquid, the cross-linking curing finishing liquid, and the hydrophilic softening finishing liquid, the final flame-retardant functional fabric has both long-lasting flame-retardant properties, excellent moisture absorption and breathability, excellent washability, and a soft hand feel, thus meeting the usage requirements of welding protective clothing fabrics. Detailed Implementation

[0063] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0064] Preparation Example 1-1 A modified epoxy triazine resin flame retardant, the preparation method of which includes the following steps: (1) Dissolve hexafluorocyclotriazine nitrile in acetone to prepare a 20% mass fraction solution, add phenol and ammonium naphthalenesulfonate, and stir at 40°C for 4 h. The molar ratio of phenol to hexafluorocyclotriazine nitrile is 3:1, and the amount of ammonium naphthalenesulfonate added is 3% of the mass of phenol, to obtain a phenoxy-substituted epoxytriazine intermediate. (2) Polyethylene glycol monomethyl ether with a number average molecular weight of 200 was added to the phenoxy-substituted epoxy triazine intermediate obtained in step (1), and the reaction was carried out at 60°C for 3 h, wherein the molar ratio of polyethylene glycol monomethyl ether to hexafluorocyclotriazine nitrile was 1:1, and a hydrophilic grafted modified product was obtained. (3) Add allyl alcohol to the hydrophilic graft modified product obtained in step (2) and react at 50°C for 2 h, wherein the molar ratio of allyl alcohol to hexafluorocyclotriazine nitrile is 0.6:1. Remove the solvent and by-products by vacuum distillation to obtain the modified epoxy triazine resin flame retardant.

[0065] Preparation Examples 1-2 A modified epoxy triazine resin flame retardant, the preparation method of which includes the following steps: (1) Dissolve hexafluorocyclotriazine nitrile in acetone to prepare a 10% mass fraction solution, add phenol and ammonium naphthalenesulfonate, and stir at 50°C for 5 h. The molar ratio of phenol to hexafluorocyclotriazine nitrile is 3.5:1, and the amount of ammonium naphthalenesulfonate added is 4% of the mass of phenol, to obtain a phenoxy-substituted epoxytriazine intermediate. (2) Polyethylene glycol monomethyl ether with a number average molecular weight of 300 was added to the phenoxy-substituted epoxy triazine intermediate obtained in step (1), and the reaction was carried out at 70°C for 4 h. The molar ratio of polyethylene glycol monomethyl ether to hexafluorocyclotriazine nitrile was 1.2:1, and a hydrophilic grafted modified product was obtained. (3) Add allyl alcohol to the hydrophilic graft modified product obtained in step (2) and react at 60°C for 3 h, wherein the molar ratio of allyl alcohol to hexafluorocyclotriazine nitrile is 0.8:1. Remove the solvent and by-products by vacuum distillation to obtain the modified epoxy triazine resin flame retardant.

[0066] Preparation Examples 1-3 A modified epoxy triazine resin flame retardant, the preparation method of which includes the following steps: (1) Dissolve hexafluorocyclotriazine nitrile in acetone to prepare a 30% mass fraction solution, add phenol and ammonium naphthalenesulfonate, and stir at 60°C for 6 h. The molar ratio of phenol to hexafluorocyclotriazine nitrile is 4:1, and the amount of ammonium naphthalenesulfonate added is 5% of the mass of phenol, to obtain a phenoxy-substituted epoxytriazine intermediate. (2) Polyethylene glycol monomethyl ether with a number average molecular weight of 400 was added to the phenoxy-substituted epoxy triazine intermediate obtained in step (1), and the reaction was carried out at 80°C for 5 h. The molar ratio of polyethylene glycol monomethyl ether to hexafluorocyclotriazine nitrile was 1.5:1, and a hydrophilic grafted modified product was obtained. (3) Add allyl alcohol to the hydrophilic graft modified product obtained in step (2) and react at 70°C for 4 h, wherein the molar ratio of allyl alcohol to hexafluorocyclotriazine nitrile is 1:1. Remove the solvent and by-products by vacuum distillation to obtain the modified epoxy triazine resin flame retardant.

[0067] Preparation Example 2-1 A modified polycarboxylic acid crosslinking agent, the preparation method of which includes the following steps: (1) Dissolve butene tetracarboxylic acid in deionized water to prepare a solution with a mass fraction of 20%, add polyethylene glycol 400, and stir at 80°C for 1 h for esterification reaction, wherein the molar ratio of polyethylene glycol 400 to butene tetracarboxylic acid is 1:5, to obtain an internally plasticized esterification product. (2) Add itaconic acid to the internally plasticized esterified product obtained in step (1) and react at 75°C for 40 min to introduce a copolymer crosslinking structure, wherein the molar ratio of itaconic acid to butene tetracarboxylic acid is 1:3 to obtain an intermediate product. (3) The intermediate product obtained in step (2) and citric acid are stirred and complexed at 60°C for 30 min, wherein the molar ratio of citric acid to butene tetracarboxylic acid is 1:6. The mixture is then naturally cooled to room temperature to obtain the modified polycarboxylic acid crosslinking agent.

[0068] Preparation Example 2-2 A modified polycarboxylic acid crosslinking agent, the preparation method of which includes the following steps: (1) Dissolve butene tetracarboxylic acid in deionized water to prepare a solution with a mass fraction of 25%, add polyethylene glycol 400, and stir at 87°C for 1.5 h for esterification reaction. The molar ratio of polyethylene glycol 400 to butene tetracarboxylic acid is 1:6.5 to obtain an internally plasticized esterification product. (2) Add itaconic acid to the internally plasticized esterified product obtained in step (1) and react at 80°C for 50 min to introduce a copolymer crosslinking structure, wherein the molar ratio of itaconic acid to butene tetracarboxylic acid is 1:4 to obtain an intermediate product. (3) Add citric acid to the intermediate product obtained in step (2) and stir the complexation reaction at 65°C for 40 min, wherein the molar ratio of citric acid to butene tetracarboxylic acid is 1:8. Cool naturally to room temperature to obtain the modified polycarboxylic acid crosslinking agent.

[0069] Preparation Examples 2-3 A modified polycarboxylic acid crosslinking agent, the preparation method of which includes the following steps: (1) Dissolve butene tetracarboxylic acid in deionized water to prepare a solution with a mass fraction of 30%, add polyethylene glycol 400, and stir at 95°C for 2 h for esterification reaction, wherein the molar ratio of polyethylene glycol 400 to butene tetracarboxylic acid is 1:8, to obtain an internally plasticized esterification product. (2) Add itaconic acid to the internally plasticized esterified product obtained in step (1) and react at 85°C for 60 min to introduce a copolymer crosslinking structure, wherein the molar ratio of itaconic acid to butene tetracarboxylic acid is 1:5 to obtain an intermediate product. (3) Add citric acid to the intermediate product obtained in step (2), and stir the mixture at 70°C for 50 min to form a complex. The molar ratio of citric acid to butene tetracarboxylic acid is 1:10. Allow the mixture to cool naturally to room temperature to obtain the modified polycarboxylic acid crosslinked product. Preparation Example 3-1 A modified polyether silicone oil hydrophilic softener, the preparation of which includes the following steps: (1) Dissolve low nitrogen-containing silicone oil with a nitrogen content of 0.1% in isopropanol to prepare a solution with a mass fraction of 30%. Add alkylpropyl polyoxyethylene ether and chloroplatinic acid and carry out hydrosilylation reaction at 80°C for 4 h. The molar ratio of alkylpropyl polyoxyethylene ether to Si-H in the low nitrogen-containing silicone oil is 0.6:1, and the amount of chloroplatinic acid added is 0.003% of the mass of the low nitrogen-containing silicone oil to obtain polyether-grafted silicone oil. (2) Add 1-dodecylimidazole to the polyether-grafted silicone oil obtained in step (1) and continue the reaction at 90°C for 2 h. The molar ratio of 1-dodecylimidazole to the remaining Si-H in the low nitrogen-containing silicone oil after hydrosilylation reaction is 0.1:1, to obtain the imidazole-modified product. (3) Cool the imidazole-modified product obtained in step (2) to 60°C, add vinyltrimethoxysilane and react for 1 h to introduce active end-capping groups, wherein the molar ratio of vinyltrimethoxysilane to the final remaining Si-H in the low nitrogen content silicone oil is 0.6:1, remove the solvent by vacuum distillation to obtain the modified polyether silicone oil hydrophilic softener.

[0070] Preparation Example 3-2 (1) Dissolve low nitrogen-containing silicone oil with a nitrogen content of 0.2% in isopropanol to prepare a solution with a mass fraction of 20%, add alkylpropyl polyoxyethylene ether and chloroplatinic acid, and carry out a hydrosilylation reaction at 90°C for 5 h. The molar ratio of alkylpropyl polyoxyethylene ether to Si-H in the low nitrogen-containing silicone oil is 0.7:1, and the amount of chloroplatinic acid added is 0.004% of the mass of the low nitrogen-containing silicone oil to obtain polyether-grafted silicone oil. (2) Add 1-dodecylimidazole to the polyether-grafted silicone oil obtained in step (1) and continue the reaction at 100°C for 2.5 h. The molar ratio of 1-dodecylimidazole to the remaining Si-H in the low nitrogen-containing silicone oil after hydrosilylation reaction is 0.2:1, and the imidazole-modified product is obtained. (3) Cool the imidazole-modified product obtained in step (2) to 65°C, add vinyltrimethoxysilane and react for 1.5 h to introduce active end-capping groups, wherein the molar ratio of vinyltrimethoxysilane to the final remaining Si-H in the low nitrogen content silicone oil is 0.8:1, remove the solvent by vacuum distillation to obtain the modified polyether silicone oil hydrophilic softener.

[0071] Preparation Example 3-3 (1) Dissolve low nitrogen-containing silicone oil with a nitrogen content of 0.3% in isopropanol to prepare a solution with a mass fraction of 40%. Add alkylpropyl polyoxyethylene ether and chloroplatinic acid and carry out hydrosilylation reaction at 100°C for 6 h. The molar ratio of alkylpropyl polyoxyethylene ether to Si-H in the low nitrogen-containing silicone oil is 0.8:1, and the amount of chloroplatinic acid added is 0.005% of the mass of the low nitrogen-containing silicone oil to obtain polyether-grafted silicone oil. (2) Add 1-dodecylimidazolium to the polyether-grafted silicone oil obtained in step (1) and continue to react at 110°C for 3 hours. The molar ratio of 1-dodecylimidazolium to the remaining Si-H in the low nitrogen-containing silicone oil after hydrosilylation reaction is 0.3:1, and the imidazole-modified product is obtained. (3) Cool the imidazole-modified product obtained in step (2) to 70°C, add vinyltrimethoxysilane and react for 2 h to introduce active end-capping groups, wherein the molar ratio of vinyltrimethoxysilane to the final remaining Si-H in the low nitrogen content silicone oil is 1:1, remove the solvent by vacuum distillation, and obtain the modified polyether silicone oil hydrophilic softener.

[0072] Example 1 A flame-retardant functional fabric, the preparation method of which includes the following steps: (1) Flame retardant finishing: The modified epoxy triazine resin flame retardant obtained in Preparation Example 1-1 was mixed with deionized water at a mass ratio of 5:85 to obtain a flame retardant finishing liquid; the whole cotton plain cloth was immersed in the obtained flame retardant finishing liquid, dipped and rubbed twice, with a rub-off rate of 75%, and then pre-dried at 80°C for 1 min to obtain the fabric after flame retardant finishing. (2) Crosslinking and fixing: The modified polycarboxylic acid crosslinking agent, sodium hypophosphite and deionized water obtained in Preparation Example 2-1 are mixed, wherein the mass ratio of the modified polycarboxylic acid crosslinking agent to deionized water is 6:88 and the mass ratio of sodium hypophosphite to deionized water is 0.2:99.4 to obtain a crosslinking curing finishing liquid; the flame-retardant finished fabric obtained in step (1) is immersed in the obtained crosslinking curing finishing liquid, dipped and rolled twice, with a roll-off rate of 70%, and then baked at 160℃ for 3 min to obtain the crosslinked and fixed fabric; (3) Hydrophilic softening finishing: The modified polyether silicone oil hydrophilic softener obtained in Preparation Example 3-1 and deionized water are mixed at a mass ratio of 2:94 to obtain a hydrophilic softening finishing solution. The cross-linked and fixed fabric obtained in step (2) is immersed in the obtained hydrophilic softening finishing solution, and then dipped and rolled twice. The roll-off rate is 65%, and the fabric after hydrophilic softening finishing is obtained. (4) Shaping and drying: The hydrophilic and soft fabric obtained in step (3) is dried and shaped at 120°C for 4 min to obtain the flame-retardant functional fabric.

[0073] Example 2 A flame-retardant functional fabric, the preparation method of which includes the following steps: (1) Flame retardant finishing: The modified epoxy triazine resin flame retardant obtained in Preparation Example 1-2 was mixed with deionized water at a mass ratio of 10:90 to obtain a flame retardant finishing solution. The cotton plain fabric was immersed in the obtained flame retardant finishing solution, dipped and rubbed twice, with a rubbed residue rate of 82%. Then it was pre-dried at 90°C for 2 min to obtain the fabric after flame retardant finishing. (2) Crosslinking and fixing: The modified polycarboxylic acid crosslinking agent, sodium hypophosphite and deionized water obtained in Preparation Example 2-2 are mixed, wherein the mass ratio of the modified polycarboxylic acid crosslinking agent to deionized water is 9:91 and the mass ratio of sodium hypophosphite to deionized water is 0.4:99.6 to obtain a crosslinking curing finishing liquid; the flame-retardant finished fabric obtained in step (1) is immersed in the obtained crosslinking curing finishing liquid, dipped and rolled twice, with a roll residue of 77%, and then baked at 170℃ for 4 min to obtain the crosslinked and fixed fabric; (3) Hydrophilic softening finishing: The modified polyether silicone oil hydrophilic softener obtained in Preparation Example 3-2 and deionized water are mixed at a mass ratio of 4:96 to obtain a hydrophilic softening finishing solution. The cross-linked and fixed fabric obtained in step (2) is immersed in the obtained hydrophilic softening finishing solution, and then dipped and rolled twice. The roll-off rate is 72% to obtain the hydrophilic softened fabric. (4) Shaping and drying: The hydrophilic and soft fabric obtained in step (3) is dried and shaped at 135°C for 5 min to obtain the flame-retardant functional fabric.

[0074] Example 3 A flame-retardant functional fabric, the preparation method of which includes the following steps: (1) Flame retardant finishing: The modified epoxy triazine resin flame retardant obtained in Preparation Examples 1-3 is mixed with deionized water at a mass ratio of 5:95 to obtain a flame retardant finishing liquid. The cotton plain fabric is immersed in the obtained flame retardant finishing liquid, dipped and rubbed twice, with a rubbed residue rate of 90%. Then it is pre-dried at 100℃ for 3 min to obtain the fabric after flame retardant finishing. (2) Crosslinking and fixing: The modified polycarboxylic acid crosslinking agent, sodium hypophosphite and deionized water obtained in Preparation Example 2-3 are mixed, wherein the mass ratio of modified polycarboxylic acid crosslinking agent to deionized water is 12:94 and the mass ratio of sodium hypophosphite to deionized water is 0.6:99.8 to obtain a crosslinking curing finishing liquid; the flame-retardant finished fabric obtained in step (1) is immersed in the obtained crosslinking curing finishing liquid, dipped and rolled twice, with a roll-off rate of 85%, and then baked at 180°C for 5 min to obtain the crosslinked and fixed fabric; (3) Hydrophilic softening finishing: The modified polyether silicone oil hydrophilic softener obtained in Preparation Example 3-3 and deionized water are mixed at a mass ratio of 6:98 to obtain a hydrophilic softening finishing solution. The cross-linked and fixed fabric obtained in step (2) is immersed in the obtained hydrophilic softening finishing solution, and then dipped and rolled twice. The roll-off rate is 80% to obtain the hydrophilic softened fabric. (4) Shaping and drying: The hydrophilic and soft fabric obtained in step (3) is dried and shaped at 150°C for 6 min to obtain the flame-retardant functional fabric.

[0075] Example 4 A flame-retardant functional fabric, which differs from Example 1 in that the base fabric is immersed in the obtained flame-retardant finishing liquid for one dip and one roll, with a roll-off rate of 75%, while other materials and steps are the same as in Example 1.

[0076] Example 5 A flame-retardant functional fabric, which differs from Example 1 in that the base fabric is immersed in the obtained cross-linking curing finishing liquid for one dip and one roll, with a roll-off rate of 70%, and other materials and steps are the same as in Example 1.

[0077] Example 6 A flame-retardant functional fabric, which differs from Example 1 in that the base fabric is immersed in the obtained hydrophilic softening finishing liquid for one dip and one roll, with a roll-off rate of 65%, and other materials and steps are the same as in Example 1.

[0078] Comparative Example 1 A flame-retardant functional fabric, which differs from Example 1 in that untreated hexafluorocyclotriazine nitrile is used to replace the modified epoxy triazine resin flame retardant obtained in Preparation Example 1-1, while other materials and steps are the same as in Example 1.

[0079] Comparative Example 2 A flame-retardant functional fabric, which differs from Example 1 in that untreated butene tetracarboxylic acid is used to replace the modified polycarboxylic acid crosslinking agent obtained in Preparation Example 2-1, while other materials and steps are the same as in Example 1.

[0080] Comparative Example 3 A flame-retardant functional fabric, which differs from Example 1 in that it uses untreated low-nitrogen silicone oil with a nitrogen content of 0.1% to replace the modified polyether silicone oil hydrophilic softener obtained in Preparation Example 3-1, while other materials and steps are the same as in Example 1.

[0081] Performance testing: (1) Flame retardant performance: Tested according to the method provided in GB / T5455-2014.

[0082] (2) Water wash resistance: Tested according to the method provided in GB / T5455-2014.

[0083] (3) Feel: Tested according to the method provided in GB / T23329-2009.

[0084] The fabrics provided in Examples 1-6 and Comparative Examples 1-3 were tested according to the above test methods, and the test results are shown in Table 1: Table 1 According to the data in Table 1: After 50 washes, the fabrics provided in Examples 1-6 exhibit an afterflame time of no more than 2 seconds, a smoldering time of no more than 2.3 seconds, and a damaged length of no more than 68 mm. A short afterflame time indicates rapid self-extinguishing after the fire source is removed, minimizing the risk of fire spread. A short smoldering time indicates a low risk of prolonged smoldering, low risk of flameless combustion, and high safety. A low damaged length indicates a small flame spread range, excellent thermal protection, and good structural integrity. Furthermore, the increase in damaged length after 50 washes is no more than 22.3%, indicating minimal degradation of flame retardant properties. The flame retardant and crosslinking agent are firmly bonded to the fibers through chemical bonding, resulting in long-lasting flame retardant functionality. Additionally, the drape coefficient of the fabrics provided in Examples 1-6 is no more than 48%, indicating softness, good drape, and high wearing comfort.

[0085] Compared with Example 1, the fabrics provided in Comparative Examples 1 to 3 cannot simultaneously possess excellent flame retardant properties, washability, and hand feel.

[0086] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A flame-retardant functional fabric, characterized in that, The flame-retardant functional fabric is obtained by sequentially impregnating and padding the base fabric with a flame-retardant finishing liquid, a cross-linking curing finishing liquid, and a hydrophilic softening finishing liquid. The flame-retardant finishing liquid comprises a modified epoxy triazine resin flame retardant and water. The raw materials of the modified epoxy triazine resin flame retardant include hexafluorocyclotriazine nitrile, phenol, ammonium naphthalene sulfonate, polyethylene glycol monomethyl ether, and allyl alcohol. The crosslinking curing finishing liquid includes a modified polycarboxylic acid crosslinking agent, a reducing agent, and water. The raw materials for the modified polycarboxylic acid crosslinking agent include butene tetracarboxylic acid, polyethylene glycol, itaconic acid, and citric acid. The hydrophilic softening finishing liquid comprises a modified polyether silicone oil hydrophilic softener and water. The raw materials of the modified polyether silicone oil hydrophilic softener include nitrogen-containing silicone oil, alkylpropyl polyoxyethylene ether, 1-dodecylimidazolium and vinyltrimethoxysilane.

2. The flame-retardant functional fabric according to claim 1, characterized in that, The modified epoxy triazine resin flame retardant in the flame retardant finishing liquid has a mass percentage content of 4-10%. Preferably, the modified epoxy triazine resin flame retardant is prepared by the following method, which includes the following steps: (A1) Dissolve hexafluorocyclotriazine nitrile in acetone, add phenol and ammonium naphthalenesulfonate to react and obtain phenoxy-substituted epoxytriazine intermediate; (A2) The phenoxy-substituted triazine oxide intermediate obtained in step (A1) is reacted with polyethylene glycol monomethyl ether to obtain a hydrophilic grafted modified product. (A3) React the hydrophilic grafted modified product obtained in step (A2) with allyl alcohol, remove the solvent, and obtain the modified epoxy triazine resin flame retardant. Preferably, the reaction in step (A1) is carried out at a temperature of 40-60°C for 4-6 hours. Preferably, the reaction in step (A2) is carried out at a temperature of 60-80°C for 3-5 hours. Preferably, the reaction in step (A3) is carried out at a temperature of 50-70°C for 2-4 hours.

3. The flame-retardant functional fabric according to claim 1 or 2, characterized in that, The modified polycarboxylic acid crosslinking agent in the crosslinking curing finishing liquid has a mass percentage content of 5-12%. Preferably, the modified polycarboxylic acid crosslinking agent is prepared by the following method, which includes the following steps: (B1) Butene tetracarboxylic acid is dissolved in water and polyethylene glycol is added to react, resulting in an internally plasticized esterified product; (B2) React the internally plasticized esterified product obtained in step (B1) with itaconic acid to obtain an intermediate product; (B3) The intermediate product obtained in step (B2) is reacted with citric acid to obtain the modified polycarboxylic acid crosslinking agent; Preferably, the reaction in step (B1) is carried out at a temperature of 80-95°C for 1-2 hours. Preferably, the reaction in step (B2) is carried out at a temperature of 75-85°C for 40-60 minutes. Preferably, the reaction in step (B3) is carried out at a temperature of 60-70°C for 30-50 minutes.

4. The flame-retardant functional fabric according to any one of claims 1 to 3, characterized in that, The mass percentage of reducing agent in the crosslinking curing finishing liquid is 0.2~0.6%; Preferably, the reducing agent includes any one or a combination of at least two of sodium hypophosphite, sodium phosphite, or sodium dihydrogen phosphate.

5. The flame-retardant functional fabric according to any one of claims 1 to 4, characterized in that, The modified polyether silicone oil hydrophilic softener in the hydrophilic softening liquid has a mass percentage content of 2-6%. Preferably, the modified polyether silicone oil hydrophilic softener is prepared by the following method, which includes the following steps: (C1) Nitrogen-containing silicone oil is dissolved in isopropanol, and alkylpropyl polyoxyethylene ether and catalyst are added to react and obtain polyether-grafted silicone oil. (C2) The polyether-grafted silicone oil obtained in step (C1) is reacted with 1-dodecylimidazolium to obtain an imidazolium-modified product; (C3) The imidazolized modified product obtained in step (C2) is reacted with vinyltrimethoxysilane to obtain the modified polyether silicone oil hydrophilic softener; Preferably, the reaction in step (C1) is carried out at a temperature of 80-100°C for 4-6 hours. Preferably, the reaction in step (C2) is carried out at a temperature of 90-110°C for 2-3 hours. Preferably, the reaction in step (C3) is carried out at a temperature of 60-70°C for 1-2 hours.

6. A method for preparing a flame-retardant functional fabric as described in any one of claims 1 to 5, characterized in that, The preparation method includes the following steps: (1) Flame retardant finishing: The base fabric is dipped and rubbed twice in the flame retardant finishing solution and then dried to obtain the flame retardant finished fabric. (2) Cross-linking and fixing: The flame-retardant finished fabric is dipped and rubbed twice in the cross-linking curing solution and then dried to obtain the cross-linked and fixed fabric. (3) Hydrophilic softening finishing: The cross-linked and fixed fabric is dipped and rolled twice in a hydrophilic softening finishing solution, and then dried and shaped to obtain the flame-retardant functional fabric.

7. The preparation method according to claim 6, characterized in that, The roll residue after the two dips and two rolls in step (1) is 75-90%; Preferably, the drying temperature in step (1) is 80~100℃ and the time is 1~3 min.

8. The preparation method according to claim 6 or 7, characterized in that, The roll residue after the two dips and two rolls in step (2) is 70-85%; Preferably, the drying temperature in step (2) is 160~180℃ and the time is 3~5 min.

9. The preparation method according to any one of claims 6 to 8, characterized in that, The roll residue after the two dips and two rolls in step (3) is 65-80%; Preferably, the drying and shaping temperature in step (2) is 120~150℃ and the time is 4~6 min.

10. A welding protective suit, characterized in that, The welding protective clothing includes the flame-retardant functional fabric as described in any one of claims 1 to 5.

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