High-breathability flame-retardant antistatic waterproof fabric and preparation method thereof

Abstract

The invention relates to the technical field of functional textiles, and discloses a high-breathability flame-retardant antistatic waterproof fabric and a preparation method thereof.The high-breathability flame-retardant antistatic waterproof fabric is composed of composite functional fibers; the composite functional fiber has a skin-core structure; a core layer of the skin-core structure is formed by polymerizing a core layer composition; the core layer composition comprises the following components: a main body structure monomer, an intrinsic flame-retardant monomer, a permanent antistatic monomer and a hydrophobic and phase separation induction monomer; a skin layer of the skin-core structure is formed by polymerizing a skin layer composition, and the skin layer composition comprises the following components: a main body structure monomer, an intrinsic flame-retardant monomer, a permanent antistatic monomer and a hydrophobic and phase separation induction monomer. A skin-core structure with gradient chemical components is constructed in a single fiber, and hydrophilic and hydrophobic functional groups are subjected to regionalization design, so that the technical effect that high air permeability and high waterproofness coexist in a synergistic manner is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of functional textiles, in particular to a highly breathable, flame-retardant, antistatic and waterproof fabric and a preparation method thereof. Background Art

[0002] In many professional fields, such as outdoor exploration, industrial production, and emergency rescue, the environments workers face place extremely demanding demands on protective clothing. These garments must effectively protect against rain, mitigate the risks posed by static electricity buildup, and provide critical flame retardant protection against fire. Furthermore, high-intensity work activities generate significant amounts of perspiration, and clothing must be able to quickly dissipate this moisture to maintain dryness and comfort. Therefore, developing high-performance fabrics that systematically integrate multiple functionalities—waterproofing, breathability, antistatic properties, and flame retardancy—has significant practical significance and application value.

[0003] Existing technologies provide some mature solutions for achieving some of the above functions. To obtain waterproof properties, the industry often uses high-density weaving or applying polyurethane coating on the fabric surface. These methods can effectively form a physical barrier on the fabric surface and provide reliable resistance to liquid water penetration. In order to improve wearing comfort, there is also a method of laminating microporous films (such as polytetrafluoroethylene films) to add a functional layer to the fabric that allows water vapor molecules to pass through. In addition, for giving fabrics specific functions such as flame retardancy or antistatic, post-finishing technology is a widely used industrial method that can apply chemical additives with specific functions to the formed fabric.

[0004] However, existing technologies have inherent limitations in achieving multifunctional synergy. First, there is a fundamental conflict in the realization mechanism of its waterproof and breathable functions. The pursuit of a dense structure with ultimate waterproofness will inevitably sacrifice breathability, and vice versa. The two properties will increase and decrease at the same time, making it difficult to take both into account. Second, the functionality imparted by post-finishing technology is based on the physical adhesion of functional additives to the fiber surface. This adhesion will gradually weaken under the friction of repeated washing and daily wear, resulting in insufficient durability of the function and an inability to meet the needs of long-term protection. Finally, if an attempt is made to fundamentally solve the above problems through chemical synthesis, huge process challenges will be faced. The complex reaction kinetics and melt rheological behavior of integrating multiple functional monomers with different chemical properties into a single polymer spinning process are difficult to effectively control through traditional step-by-step processes, which hinders the stable production and technical realization of high-performance composite functional fibers. Summary of the Invention

[0005] In response to the shortcomings of the existing technology, the present invention provides a highly breathable, flame-retardant, anti-static and waterproof fabric and a preparation method thereof, which solves the technical problems in the existing technology of difficulty in coordinating waterproof and breathable properties, insufficient functional durability, and difficulty in integrated preparation of complex functional fibers.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: A first aspect of the present invention provides a highly breathable, flame-retardant, antistatic and waterproof fabric.

[0007] The fabric is composed of a composite functional fiber, the notable structural feature of which is its sheath-core structure. This sheath-core structure is not formed by physically combining two different polymers, but rather by integrating two compositions with gradient differences in chemical composition through in-situ polymerization, thus forming a functionally synergistic gradient structure within a single fiber.

[0008] Specifically, the core layer and the skin layer of the skin-core structure are respectively formed by polymerizing a core layer composition and a skin layer composition.

[0009] The core layer composition comprises the following components by weight: 100 parts of a main structural monomer, 25-45 parts of an intrinsically flame-retardant monomer, 30-55 parts of a permanent antistatic monomer, and 5-15 parts of a hydrophobic and phase-separation-inducing monomer. Through polymerization, these monomers covalently bond to form the core layer polymer. The higher proportion of the permanent antistatic monomer forms hydrophilic segments within the polymer, which build an internal network for electrostatic charge conduction. The lower proportion of the hydrophobic and phase-separation-inducing monomer forms incompatible microdomains with the hydrophilic segments.

[0010] The skin layer composition comprises the following components by weight: 100 parts of a main structural monomer, 25-45 parts of an intrinsically flame-retardant monomer, 5-20 parts of a permanent antistatic monomer, and 20-40 parts of a hydrophobic and phase-separation-inducing monomer. Through polymerization, these monomers covalently bond to form the skin layer polymer. The higher proportion of the hydrophobic and phase-separation-inducing monomer forms hydrophobic segments in the polymer. These segments tend to accumulate on the fiber surface, forming a low-surface-energy physical barrier that prevents liquid water penetration. The lower proportion of the permanent antistatic monomer also forms incompatible microdomains with the hydrophobic segments.

[0011] In some specific embodiments: The main structural monomer may be a monomer capable of forming polyester or polyamide, such as a combination of terephthalic acid and 1,4-butanediol, or caprolactam.

[0012] The intrinsic flame retardant monomer may be a phosphorus- or nitrogen-containing difunctional compound, such as 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO-HQ), which is introduced into the polymer backbone through copolymerization to achieve a permanent flame retardant effect.

[0013] The permanent antistatic monomer may be a polyether bifunctional compound, such as polyethylene glycol with a number average molecular weight of 1000-4000.

[0014] The hydrophobic and phase separation inducing monomer may be an organosilicon or fluorine-containing difunctional compound, such as hydroxyl-terminated polydimethylsiloxane or fluorine-containing polyether diol.

[0015] In some preferred embodiments, the core layer composition and the skin layer composition each further comprise 3-8 parts by weight of a dynamically reversible bond monomer. Such monomers, for example, are used to form a Diels-Alder reversible reaction system, and specifically may comprise a combination of a difunctional monomer containing a furan group and a difunctional monomer containing a maleimide group, wherein the difunctional monomer containing a furan group is 2,5-furan dimethanol and the difunctional monomer containing a maleimide group is 4-maleimidobenzoic acid. During polymerization, these monomers form covalent bonds between polymer chains or segments that can dissociate and recombine at specific temperatures.

[0016] A second aspect of the present invention provides a method for preparing the above-mentioned highly breathable, flame-retardant, antistatic and waterproof fabric.

[0017] The preparation method comprises the following steps: Step 1: Preparation and pretreatment of composition raw materials.

[0018] Weigh the solid monomers required for the core layer composition and the skin layer composition according to the stated weight ratios. Place the two sets of monomers in a vacuum drying oven at 80-110°C and a vacuum of 0.08-0.095 MPa for 12-24 hours to remove moisture and other volatile substances that may affect the polymerization reaction.

[0019] Step 2: Integrated reaction co-extrusion and forming of sheath-core primary fibers.

[0020] This step is the core link of the present invention. The pre-treated core layer composition and the skin layer composition are fed into a twin-screw extruder through two independent feeding systems.

[0021] Inside the extruder, a gradient temperature distribution is set along the axial direction of the screw to achieve orderly melting, polymerization reaction and homogenization of the monomers. Specifically, the gradient temperature distribution can be set as follows: the temperature in the extruder feed zone is 210-230°C to ensure smooth transportation and initial melting of the material; then in the melting and reaction zone, the temperature is gradually increased to 250-270°C to provide sufficient energy to drive the copolymerization reaction efficiently; finally, in the homogenization zone at the end of the extruder, the temperature is maintained at 240-260°C to ensure uniform melt composition and establish a stable extrusion pressure. The composition contains a dynamically reversible bond monomer. In the high-temperature reaction zone of 250-270°C, the dynamic balance of the reversible bond helps to regulate the melt viscosity and ensure the smooth progress of the polymerization reaction.

[0022] The core layer melt and the skin layer melt generated by the reaction are respectively conveyed to a skin-core composite spinning assembly, and co-extruded at a skin-core volume ratio of 1:3 to 1:5 to form a melt stream with a skin-core structure.

[0023] Subsequently, a cooling airflow at 15-28°C is used to rapidly cool and solidify the extruded melt stream. During this process, the chemically incompatible hydrophilic and hydrophobic segments in the polymer chains undergo thermally induced phase separation, forming a nanoscale, discontinuous microscopic phase structure within the fiber. This is then "frozen" by the rapid cooling process, ultimately forming nascent fibers.

[0024] Step 3: Multi-stage thermal stretching and construction of nanopore structure.

[0025] The spun fibers are subjected to a multi-stage heat stretching process. The mechanism of this step is that the relatively soft microscopic phase-separated regions formed in step 2 undergo irreversible deformation and stretching by applying mechanical stress, thereby forming interconnected micropores or channels in the fiber matrix.

[0026] Specifically, the first stage stretching is performed at a temperature of 75-95°C with a stretching ratio of 1.8-2.6, followed by a second stage stretching at a temperature of 125-155°C with a stretching ratio of 1.3-1.9. The total stretching ratio of the fiber is controlled between 3.0-4.5 to form an effective nanopore network.

[0027] Step 4: Relaxation, heat setting and winding.

[0028] The fibers, which have undergone multiple stages of heat stretching, are then heat-set at 135-160°C with a relaxation rate of 3-8%. This step aims to eliminate the internal stress generated by the stretching and stabilize the nanopore structure formed in step 3 and the overall fiber size.

[0029] The shaped fibers are oiled and wound at a speed of 1500-3500 m / min to obtain a finished composite functional fiber.

[0030] Step 5: Weaving and finishing.

[0031] The composite functional fiber is woven or knitted into a grey fabric, and then subjected to a final heat setting treatment at a temperature of 140-165°C for 30-60 seconds to obtain a finished fabric.

[0032] In summary, this application includes at least one of the following beneficial technical effects: 1. The present invention achieves the technical effect of synergistic coexistence of high air permeability and high waterproofness by constructing a skin-core structure with a chemical composition gradient inside a single fiber and regionalizing the design of hydrophilic and hydrophobic functional groups. The fiber cortex is enriched with hydrophobic groups to resist liquid water, while the core layer uses hydrophilic groups and stretching pore-forming effects to form water vapor channels. Compared with the existing solutions of post-finishing coating or multi-component physical blending, the present invention solves the fundamental shortcomings of sacrificing air permeability due to clogging of fabric pores, or failing to simultaneously optimize the two opposing properties due to functional compromise.

[0033] 2. The preparation method of the present invention polymerizes all functional monomers into the polymer main chain in the form of covalent bonds, giving the fabric absolutely permanent flame retardant and antistatic properties. The functionality comes from the intrinsic properties of the material, so it will not decay or migrate with washing or friction. It is essentially different from the traditional post-finishing technology of attaching additives to the fiber surface, completely avoiding the latter's poor functional durability, short service life, and environmental and safety risks caused by the shedding of chemical additives.

[0034] 3. The present invention adopts an integrated reaction co-extrusion process and introduces a dynamic reversible bond system to achieve a one-step continuous manufacturing process from chemical monomers to complex structural functional fibers. The highly integrated preparation method utilizes the reversible characteristics of dynamic bonds in the high-temperature polymerization zone to effectively regulate the melt fluidity of the multi-component reaction system, and can accurately construct and solidify the microscopic phase separation structure inside the fiber. Compared with the existing process in which synthesis and spinning are carried out step by step and the microscopic morphology is difficult to control, the present invention provides an efficient and highly structurally controllable manufacturing path, which solves the problem of complex copolymers being difficult to continuously process. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 Schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0036] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the present specification. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0037] The sources and specifications of the main raw materials and reagents used in the following examples and comparative examples are as follows. Reagents not specifically specified are all commercially available products of analytical grade or higher.

[0038] 1. Main structure monomer: Caprolactam, CAS number: 105-60-2; Terephthalic acid, CAS number: 100-21-0; 1,4-Butanediol, CAS number: 110-63-4.

[0039] 2. Intrinsic flame retardant monomer: 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, CAS No.: 99208-50-1.

[0040] 3. Permanent antistatic monomer: Polyethylene glycol, CAS number: 25322-68-3.

[0041] 4. Hydrophobic and phase separation inducing monomers: Hydroxyl-terminated polydimethylsiloxane, CAS number: 70131-67-8; In the present invention, the fluorinated polyether diol may be α,ω-dihydroxy perfluoropolyether with a number average molecular weight in the range of 1500-2500.

[0042] 5. Dynamic reversible bond monomer: Difunctional monomer containing furan group: 2,5-furan dimethanol, CAS number: 1883-75-6; Monomer containing maleimide group: 4-maleimidobenzoic acid, CAS number: 1693-55-6.

[0043] Please see the attached Figure 1 : Example 1: Component ratio: Core layer composition: Main structural monomer (caprolactam): 100 parts by weight; Intrinsically flame-retardant monomer (10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide): 35 parts by weight; Permanent antistatic monomer (polyethylene glycol with a number average molecular weight of 2000): 42 parts by weight; Hydrophobic and phase separation inducing monomer (hydroxyl-terminated polydimethylsiloxane): 10 parts by weight; Dynamic reversible bond monomer (a bifunctional monomer combination containing a furan group and a maleimide group): 5 parts by weight; Cortical composition: Main structural monomer (caprolactam): 100 parts by weight; Intrinsically flame-retardant monomer (10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide): 35 parts by weight; Permanent antistatic monomer (polyethylene glycol with a number average molecular weight of 2000): 12 parts by weight; Hydrophobic and phase separation inducing monomer (hydroxyl-terminated polydimethylsiloxane): 30 parts by weight; Dynamic reversible bond monomer (a bifunctional monomer combination containing a furan group and a maleimide group): 5 parts by weight.

[0044] Preparation steps: 1. Pretreatment: Dry the solid monomers required for the core layer and skin layer compositions separately in a vacuum drying oven. The drying temperature is set at 95°C, the vacuum degree is 0.09 MPa, and the drying time is 18 hours.

[0045] 2. Integrated Reaction Coextrusion: The two dried materials were fed separately into a twin-screw extruder. The extruder temperatures were set at 220°C in the feed zone, 260°C in the reaction zone, and 250°C in the homogenization zone. The screw speed was 250 rpm. The two melts generated by the reaction were conveyed to a sheath-core composite spinning assembly with a sheath-core volume ratio of 1:4. Coextrusion was performed at 265°C. The extruded filaments were cooled and solidified using a cooling airflow at 22°C.

[0046] 3. Multi-stage heat stretching: The cured spun fibers are subjected to two-stage heat stretching. The first stage stretching temperature is 85°C and the stretching ratio is 2.2; the second stage stretching temperature is 140°C and the stretching ratio is 1.6.

[0047] 4. Relaxation, heat setting and winding: The stretched fiber is heat set at 150°C with a relaxation rate of 5%. The set fiber is oiled and wound at a speed of 2500m / min.

[0048] 5. Weaving and finishing: Plain weave is used for weaving to produce grey fabric. The grey fabric is subjected to a final heat setting treatment at 155°C for 45 seconds to obtain the finished fabric.

[0049] Example 2: Component ratio: Core layer composition: Main structural monomers (terephthalic acid and 1,4-butanediol): 100 parts by weight; Intrinsically flame retardant monomer (DOPO-HQ): 25 parts by weight; Permanent antistatic monomer (polyethylene glycol with a number average molecular weight of 1000): 30 parts by weight; Hydrophobic and phase separation inducing monomer (fluorinated polyether diol): 5 parts by weight; Dynamic reversible bond monomer (a bifunctional monomer combination containing a furan group and a maleimide group): 3 parts by weight; Cortical composition: Main structural monomers (terephthalic acid and 1,4-butanediol): 100 parts by weight; Intrinsically flame retardant monomer (DOPO-HQ): 25 parts by weight; Permanent antistatic monomer (polyethylene glycol with a number average molecular weight of 1000): 5 parts by weight; Hydrophobic and phase separation inducing monomer (fluorinated polyether diol): 20 parts by weight; Dynamic reversible bond monomer (a bifunctional monomer combination containing a furan group and a maleimide group): 3 parts by weight.

[0050] Preparation steps: 1. Pretreatment: Dry the solid monomers required for the core layer and skin layer compositions separately in a vacuum drying oven. The drying temperature is set at 80°C, the vacuum degree is 0.08 MPa, and the drying time is 12 hours.

[0051] 2. Integrated Reaction Coextrusion: The two dried materials were fed separately into a twin-screw extruder. The extruder temperatures were set at 210°C in the feed zone, 250°C in the reaction zone, and 240°C in the homogenization zone. The screw speed was 120 rpm. The two melts generated by the reaction were conveyed to a sheath-core composite spinning assembly with a sheath-core volume ratio of 1:5. Coextrusion was performed at 255°C. The extruded filaments were cooled and solidified using a 28°C cooling airflow.

[0052] 3. Multi-stage heat stretching: The cured spun fibers are subjected to two-stage heat stretching. The first stage stretching temperature is 75°C and the stretching ratio is 1.8; the second stage stretching temperature is 125°C and the stretching ratio is 1.3.

[0053] 4. Relaxation, heat setting and winding: The stretched fiber is heat set at 135°C with a relaxation rate of 8%. The set fiber is oiled and wound at a speed of 1500m / min.

[0054] 5. Weaving and finishing: The grey fabric is made by weft knitting process. The grey fabric is finally heat-set at 140℃ for 60 seconds to obtain the finished fabric.

[0055] Example 3: Component ratio: Core layer composition: Main structural monomer (caprolactam): 100 parts by weight; Intrinsically flame retardant monomer (DOPO-HQ): 45 parts by weight; Permanent antistatic monomer (polyethylene glycol with a number average molecular weight of 4000): 55 parts by weight; Hydrophobic and phase separation inducing monomer (hydroxyl-terminated polydimethylsiloxane): 15 parts by weight; Dynamic reversible bond monomer (a bifunctional monomer combination containing a furan group and a maleimide group): 8 parts by weight; Cortical composition: Main structural monomer (caprolactam): 100 parts by weight; Intrinsically flame retardant monomer (DOPO-HQ): 45 parts by weight; Permanent antistatic monomer (polyethylene glycol with a number average molecular weight of 4000): 20 parts by weight; Hydrophobic and phase separation inducing monomer (hydroxyl-terminated polydimethylsiloxane): 40 parts by weight; Dynamic reversible bond monomer (a bifunctional monomer combination containing a furan group and a maleimide group): 8 parts by weight.

[0056] Preparation steps: 1. Pretreatment: Dry the solid monomers required for the core layer and skin layer compositions separately in a vacuum drying oven. The drying temperature is set at 110°C, the vacuum degree is 0.095 MPa, and the drying time is 24 hours.

[0057] 2. Integrated Reaction Coextrusion: The two dried materials were fed separately into a twin-screw extruder. The extruder temperature was set at 230°C in the feed zone, 270°C in the reaction zone, and 260°C in the homogenization zone. The screw speed was 350 rpm. The two melts generated by the reaction were conveyed to a sheath-core composite spinning assembly with a sheath-core volume ratio of 1:3. Coextrusion was performed at 275°C. The extruded filaments were cooled and solidified using a 15°C cooling airflow.

[0058] 3. Multi-stage heat stretching: The cured spun fibers are subjected to two-stage heat stretching. The first stage stretching temperature is 95°C and the stretching ratio is 2.6; the second stage stretching temperature is 155°C and the stretching ratio is 1.9.

[0059] 4. Relaxation, heat setting and winding: The stretched fiber is heat set at 160°C with a relaxation rate of 3%. The set fiber is oiled and wound at a speed of 3500m / min.

[0060] 5. Weaving and finishing: The fabric is woven with twill weave to produce grey fabric. The grey fabric is subjected to a final heat setting treatment at 165°C for 30 seconds to obtain the finished fabric.

[0061] Comparative Example 1: Compared with Example 1, the difference is that the core-skin structure is not adopted, but the core layer composition in Example 1 is prepared into a homogeneous single-structure fiber through a conventional melt spinning process, and the rest are the same.

[0062] Comparative Example 2: Compared with Example 1, the difference is that no hydrophobic and phase separation inducing monomer (hydroxyl-terminated polydimethylsiloxane) is added to the core layer composition and the skin layer composition, and the rest are the same.

[0063] Comparative Example 3: Compared with Example 1, the difference is that the amount of the permanent antistatic monomer (polyethylene glycol with a number average molecular weight of 2000) in the core layer composition is adjusted from 42 parts by weight to 70 parts by weight, and the rest are the same.

[0064] Comparative Example 4: Compared with Example 1, the difference is that no dynamic reversible bond monomer is added to the core layer composition and the skin layer composition, and the rest are the same.

[0065] Comparative Example 5: Compared with Example 1, the difference is that step 3 "multi-stage heat stretching" is omitted in the preparation process, and the as-spun fiber is directly subjected to step 4 of relaxation, heat setting and winding after cooling and solidification, and the rest are the same.

[0066] Comparative Example 6: Compared with Example 1, the difference is that the integrated reaction co-extrusion preparation method is not adopted, but the core layer composition and the skin layer composition are first polymerized in the reactor separately to make two polymer slices; then the two polymer slices are melted separately and spun through the skin-core composite spinning assembly, and the rest are the same.

[0067] Experiment 1: Purpose of the experiment: This experiment aims to verify the key role and necessity of the gradient functional design of the "skin-core structure" and the "hydrophobic and phase separation inducing monomer" in constructing waterproof and breathable properties through comparative testing.

[0068] Experimental groups: Fabric sample prepared in Example 1; Fabric sample prepared in Comparative Example 1; Fabric samples prepared in Comparative Example 2.

[0069] Experimental steps: 1. Waterproof performance test (anti-hydrostatic pressure test): According to GB / T 4744-2013, 5 specimens with a size of 100 mm × 100 mm were cut from the fabric samples of each group.

[0070] Install the sample on the sample clamp of the hydrostatic pressure tester, ensuring that the fabric surface (i.e. the cortex side) faces the pressurized water surface.

[0071] Water pressure was applied to the sample at a constant rate of 6.0 kPa / min.

[0072] Carefully observe the non-pressure surface of the specimen. When the third water droplet appears, stop pressurizing immediately and record the hydrostatic pressure value (kPa) at this time.

[0073] The average value of 5 samples in each group was calculated as the final test result.

[0074] 2. Air permeability test (moisture permeability test): According to GB / T 12704.2-2009A method (positive cup method), three circular specimens with a diameter of 70 mm were cut from the fabric samples of each group.

[0075] About 33 g of anhydrous calcium chloride was placed in the moisture permeable cup as a desiccant.

[0076] Place the sample on the mouth of the moisture permeable cup with the inner side of the fabric (ie the core layer side) facing the desiccant and seal it with wax.

[0077] Place the prepared moisture permeable cup assembly in a constant temperature and humidity chamber with a temperature of 38±0.5°C and a relative humidity of 90±2%.

[0078] After standing for 1 hour, the initial mass (m1) of the assembly was taken out and accurately weighed, and then immediately returned to the constant temperature and humidity chamber.

[0079] After being placed in the constant temperature and humidity chamber for another 23 hours, the assembly was taken out again and the final mass (m2) of the assembly was accurately weighed.

[0080] The moisture permeability (g·m -2 24h -1 ), and the average value of the three samples was taken as the final test result (the experimental data are shown in Table 1).

[0081] Table 1: Comparison of test data in Experiment 1 sample Hydrostatic pressure resistance (kPa) <![CDATA[Water vapor permeability (g·m -2 ·24h -1 )]]> Example 1 18.3 8562 Comparative Example 1 2.1 7815 Comparative Example 2 3.7 2148 From Table 1, we can get: Comparing the test data of Example 1 and Comparative Example 1 reveals that Example 1's hydrostatic pressure resistance is significantly higher than that of Comparative Example 1. This is due to the sheath-core structure of the composite functional fiber in Example 1, where the sheath is polymerized from a composition rich in hydrophobic groups, forming a dense, low-surface-energy protective layer on the fiber surface, effectively preventing the penetration of liquid water molecules. Comparative Example 1 employs a homogeneous structure, and the fiber as a whole exhibits the hydrophilic properties of the core composition, lacking an effective hydrophobic barrier. Consequently, its water repellency performance is poor. This result confirms the necessity of a sheath-core structure for achieving high water repellency.

[0082] Compared to Comparative Example 2, Example 1 demonstrates significant advantages in both hydrostatic pressure resistance and moisture permeability. This is due to the dual key roles played by the hydrophobic and phase-separation-inducing monomer in the technical solution of Example 1. Firstly, it accumulates in the cortex during polymerization, becoming one of the core components contributing to water resistance. Secondly, and more importantly, as an incompatible component, it drives microscopic phase separation within the polymer during fiber cooling and forming. This phase-separated structure is the prerequisite for the subsequent formation of nanoscale breathable channels during stretching.

[0083] Comprehensive analysis shows that the lack of hydrophobic and phase-separation-inducing monomers in Comparative Example 2 not only weakens the hydrophobicity of the cortex, but also fails to form an effective microscopic phase-separation structure. This results in an inability to construct continuous breathable channels during the subsequent stretching step, resulting in extremely low moisture permeability. This fully demonstrates that the present invention, through the design of a skin-core structure, combined with the internal microscopic phase separation induced by specific functional monomers and the stretching pore-forming mechanism, ultimately achieves the synergistic unification of the two opposing properties of high waterproofness and high breathability, verifying the integrity and innovation of the present invention's technical solution.

[0084] Experiment 2: Purpose of the experiment: This experiment aims to verify the rationality and importance of the ratio range, and to confirm the decisive role of special functional components (dynamic reversible bond monomers) in giving fabrics the unique technical effect of self-repair.

[0085] Experimental groups: Fabric sample prepared in Example 1; Fabric samples prepared in Comparative Example 3; Fabric samples prepared in Comparative Example 4.

[0086] Experimental steps: 1. Permanent antistatic performance test: According to GB / T 1410-2006, three specimens were cut from each group of fabric samples.

[0087] First, all samples were washed and dried for 50 cycles according to the household washing procedure specified in GB / T 8629-2017.

[0088] The washed sample was subjected to humidity conditioning treatment for 24 hours under standard atmospheric conditions of a temperature of 23±2° C. and a relative humidity of 50±5%.

[0089] Use a high resistance meter to measure the specific resistance (Ω) of the sample surface after humidity conditioning, and calculate the average value of the three samples in each group.

[0090] 2. Self-repair performance verification test: Cut 5 strip specimens of 200mm×50mm in size from the fabric samples of each group along the warp direction.

[0091] First, the breaking strength of three original specimens was tested using a tensile testing machine, and the average value was calculated as the initial strength (F0).

[0092] For the other two specimens, use a sharp blade to make a through scratch of about 10 mm in length in the center of the specimen perpendicular to the tensile direction.

[0093] The scratched sample was placed flat in an oven and heat treated at 145° C. for 30 minutes.

[0094] After the sample is cooled naturally to room temperature, its breaking strength is tested again using a tensile testing machine, and the average value is calculated as the healing strength (F1).

[0095] According to the formula: strength recovery rate (%) = (F1 / F0) × 100%, the strength recovery rate of the fabric is calculated (the experimental data are shown in Table 2).

[0096] Table 2: Comparison of test data in Experiment 2 sample Surface resistivity after washing 50 times (Ω) Strength recovery rate (%) Example 1 <![CDATA[5.1×10 8 ]]> 87 Comparative Example 3 <![CDATA[2.3×10 7 ]]> 84 Comparative Example 4 <![CDATA[6.8×10 8 ]]> 4 From Table 2, we can get: Experimental data show that the samples of Example 1 and Comparative Example 3 both exhibited excellent and stable antistatic properties after 50 washes, and their surface resistivity was much lower than that of conventional polymer materials. However, although the excess permanent antistatic monomer (hydrophilic polyethylene glycol) in Comparative Example 3 brought about a lower surface resistivity, this excess hydrophilic component would destroy the continuity and density of the hydrophobic segments in the cortical polymer, thereby potentially sacrificing the waterproof performance of the material. The ratio of Example 1 maintains the balance of the functional components while ensuring the permanent antistatic effect, verifying the rationality and necessity of the component ratio range defined by the present invention for achieving multifunctional synergy.

[0097] The comparison results of Example 1 and Comparative Example 4 clearly reveal the core role of the dynamic reversible bond monomer. After being scratched and heat treated, the sample of Example 1 has a strength recovery rate of 87%, showing a significant self-repair effect. The mechanism is that the Diels-Alder dynamic covalent bonds in its polymer network undergo reversible dissociation when heated, allowing the molecular chains to reflow, diffuse and entangle with each other at the damaged interface. When the temperature is lowered, these covalent bonds will reform, thereby repairing the physical damage and restoring the mechanical properties of the material.

[0098] In stark contrast, the polymer network of Comparative Example 4, which does not contain a dynamically reversible bond monomer, is composed of irreversible, permanent covalent bonds. This lacks a molecular mechanism for repair after damage, resulting in an extremely low strength recovery rate and permanent damage. This comparative experiment irrefutably demonstrates that dynamically reversible bond monomers are the material basis for the self-healing function of the present invention, a major innovation that distinguishes the present invention from existing technologies and greatly improves the durability and service life of the material.

[0099] Experiment 3: Purpose of the experiment: The purpose of this experiment is to verify through comparative tests that the two core process steps of "multi-stage thermal stretching" and "integrated reactive co-extrusion" in the preparation method of the present invention are indispensable for constructing the final function of the fabric (high breathability) and ensuring its basic performance (mechanical properties).

[0100] Experimental groups: Fabric sample prepared in Example 1; Fabric sample prepared in Comparative Example 5; Fabric samples prepared in Comparative Example 6.

[0101] Experimental steps: 1. Air permeability test (moisture permeability test): According to GB / T 12704.2-2009A method (positive cup method), three circular specimens with a diameter of 70 mm were cut from the fabric samples of each group.

[0102] About 33 g of anhydrous calcium chloride was placed in the moisture permeable cup as a desiccant.

[0103] Place the sample on the mouth of the moisture permeable cup with the inner side of the fabric (ie the core layer side) facing the desiccant and seal it with wax.

[0104] Place the prepared moisture permeable cup assembly in a constant temperature and humidity chamber with a temperature of 38±0.5°C and a relative humidity of 90±2%.

[0105] After standing for 1 hour, the initial mass (m1) of the assembly was taken out and accurately weighed, and then immediately returned to the constant temperature and humidity chamber.

[0106] After being placed in the constant temperature and humidity chamber for another 23 hours, the assembly was taken out again and the final mass (m2) of the assembly was accurately weighed.

[0107] The moisture permeability (g·m -2 24h -1 ), and take the average value of 3 samples as the final test result.

[0108] 2. Mechanical properties test (breaking strength test): According to GB / T 3923.1-2013, five strip specimens with a size of 300 mm × 50 mm were cut from the fabric samples in each group along the warp direction.

[0109] The sample was clamped between the upper and lower clamps of the tensile testing machine, and the initial gauge distance was set to 200 mm.

[0110] The specimen was stretched at a constant speed of 100 mm / min until it broke.

[0111] Record the maximum force the specimen withstands when it breaks, i.e. the breaking strength (N).

[0112] The average value of the five samples in each group was calculated as the final test result (the experimental data are shown in Table 3).

[0113] Table 3: Comparison of test data in Experiment 3 sample <![CDATA[Water vapor transmission rate (g·m -2 ·24h -1 )]]> Breaking strength (N) Example 1 8562 461 Comparative Example 5 1245 218 Comparative Example 6 4317 325 From Table 3 we can get: Comparing the results of Example 1 and Comparative Example 5 clearly reveals the crucial role of the multi-stage thermal stretching step. Comparative Example 5, which omitted thermal stretching, exhibited extremely low moisture permeability. This indicates that, although microscopic phase-separated regions due to chemical incompatibility have formed within the fiber after reactive coextrusion and cooling and solidification, these regions are isolated and disconnected. They represent merely the "potential" for pore formation, not actual channels. Only through the multi-stage thermal stretching process described in Example 1, by applying precisely controlled mechanical stress, can these microscopic regions be stretched and torn, forming a continuous nanoscale pore network, thereby transforming this "potential" into actual high breathability.

[0114] Comparing the data of Example 1 and Comparative Example 6, the superiority of the integrated reaction co-extrusion process can be confirmed. Comparative Example 6 adopts a step-by-step method of polymerization and then spinning. The material has undergone a longer thermal history, which may lead to uneven polymerization and coarsening and uneven distribution of microphase regions during the remelting process. Therefore, the initial structure of the fiber formed is inferior to that of Example 1. Even after the same stretching treatment, the efficiency and uniformity of the pore network finally formed are poor, resulting in a moisture permeability that is significantly lower than that of Example 1. At the same time, the more uniform internal structure also gives the fiber of Example 1 better mechanical properties, manifested as higher breaking strength.

[0115] In summary, the core technological innovation of this invention lies in the synergistic effect of integrated reactive co-extrusion and multi-stage thermal stretching. Integrated reactive co-extrusion is the foundation for constructing a uniform and fine microscopic phase-separated "precursor structure," while multi-stage thermal stretching is the key to transforming this "precursor structure" into a functional nanopore network. Both are essential, ensuring that the final fabric possesses both excellent breathability and good mechanical properties.

[0116] The examples of this specific embodiment are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are represented by the same reference numerals. Therefore, any equivalent changes made based on the structure, shape, and principle of this application should be included in the scope of protection of this application.

Claims

1. A highly breathable, flame-retardant, antistatic and waterproof fabric, characterized in that: The fabric is composed of composite functional fibers; The composite functional fiber has a skin-core structure; The core layer of the skin-core structure is formed by polymerizing a core layer composition, and the core layer composition includes the following components in parts by weight: 100 parts of main structure monomer, 25-45 parts of intrinsic flame retardant monomer, 30-55 parts of permanent antistatic monomer, 5-15 parts of hydrophobic and phase separation inducing monomer; The skin layer of the skin-core structure is formed by polymerizing a skin layer composition, and the skin layer composition includes the following components in parts by weight: 100 parts of main structure monomer, 25-45 parts of intrinsic flame retardant monomer, 5-20 parts of permanent antistatic monomer, 20-40 parts of hydrophobic and phase separation inducing monomer.

2. The highly breathable, flame-retardant, antistatic and waterproof fabric according to claim 1, characterized in that: The main structural monomer is: a combination of terephthalic acid and 1,4-butanediol, or caprolactam; The intrinsic flame retardant monomer is: 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide.

3. The highly breathable, flame-retardant, antistatic and waterproof fabric according to claim 1, characterized in that: The permanent antistatic monomer is polyethylene glycol with a number average molecular weight of 1000-4000; The hydrophobic and phase separation inducing monomer is: terminal hydroxyl polydimethylsiloxane or fluorine-containing polyether diol.

4. The highly breathable, flame-retardant, antistatic and waterproof fabric according to claim 1, characterized in that: The core layer composition and the skin layer composition also each include 3-8 parts by weight of a dynamic reversible bond monomer; The dynamic reversible bond monomer is a monomer used to form a Diels-Alder reversible reaction system, and the monomer contains both a difunctional monomer with a furan group and a difunctional monomer with a maleimide group, wherein the difunctional monomer with a furan group is 2,5-furan dimethanol, and the difunctional monomer with a maleimide group is 4-maleimidobenzoic acid.

5. A method for preparing the highly breathable, flame-retardant, antistatic and waterproof fabric according to any one of claims 1 to 4, characterized in that: The following steps are involved: Prepare a core layer composition and a skin layer composition according to parts by weight respectively; The core layer composition and the skin layer composition are subjected to an integrated reaction co-extrusion to form a primary fiber having a skin-core structure; performing multi-stage thermal stretching on the as-spun fibers; The fibers that have undergone multi-stage heat stretching are relaxed and heat-set to form composite functional fibers; The composite functional fibers are woven and finished to form highly breathable, flame-retardant, antistatic and waterproof fabrics.

6. The method for preparing a highly breathable, flame-retardant, antistatic and waterproof fabric according to claim 5, characterized in that: The preparation of the core layer composition and the skin layer composition respectively in parts by weight comprises: Pre-treating the solid monomers in the core layer composition and the skin layer composition in a vacuum drying oven respectively; The pretreatment conditions are: temperature 80-110° C., vacuum degree 0.08-0.095 MPa, and time 12-24 hours.

7. The method for preparing a highly breathable, flame-retardant, antistatic and waterproof fabric according to claim 5, characterized in that: The integrated reaction co-extrusion of the core layer composition and the skin layer composition comprises: Feeding the core layer composition and the skin layer composition into a twin-screw extruder respectively, and subjecting the components to melt polymerization reaction in a gradient temperature range of 210-270° C. to form a core layer melt and a skin layer melt; The core layer melt and the skin layer melt are conveyed to a core-skin composite spinning assembly and co-extruded at a skin-core volume ratio of 1:3 to 1:5; The extruded fiber strands are cooled and solidified by using a cooling air flow at 15-28° C. to form the nascent fibers.

8. The method for preparing a highly breathable, flame-retardant, antistatic and waterproof fabric according to claim 5, characterized in that: The multi-stage heat stretching of the as-spun fiber comprises: Performing a first-stage stretching on the as-spun fiber at a temperature of 75-95° C., with the first-stage stretching ratio being 1.8-2.6; The fiber is subjected to a second-stage stretching at a temperature of 125-155° C., the second-stage stretching ratio is 1.3-1.9, and the total stretching ratio of the fiber is 3.0-4.

5.

9. The method for preparing a highly breathable, flame-retardant, antistatic and waterproof fabric according to claim 5, characterized in that: The step of performing relaxation heat setting on the fiber after multi-stage heat stretching comprises: heat-treating the fiber after multi-stage heat drawing at a temperature of 135-160° C.; The shaped fibers are oiled and wound at a speed of 1500-3500 m / min.

10. The method for preparing a highly breathable, flame-retardant, antistatic and waterproof fabric according to claim 5, characterized in that: The weaving and finishing of the composite functional fiber comprises: Using a weaving or knitting process to make the composite functional fiber into a grey fabric; The grey fabric is subjected to a final heat setting treatment at a temperature of 140-165° C. for 30-60 seconds.

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