Stain-resistant and waterproof polyester composite fabric and preparation method thereof

Abstract

The invention relates to the technical field of fabric fabrics, in particular to preparation of a stain-resistant and waterproof polyester composite fabric. The invention discloses a stain-resistant waterproof polyester composite fabric and a preparation method thereof, the composite fabric is composed of three layers from outside to inside, the first layer is a polyester filament yarn surface layer subjected to fluorinated graphene and plant source C18 alkylsilane amphiphobic finishing; the second layer is a copolyamide hot melt adhesive net film with a melting point of 105 DEG C; and the third layer is a degradable multifunctional thermoplastic polyurethane elastomer film loaded with silver zeolite antibacterial microcapsules and conductive carbon nanotubes. An amphiphobic finishing liquid is uniformly deposited on the surface of polyester by adopting a supercritical CO2 one-step method, and nanoparticles and fibers are covalently bonded through a chitosan-citric acid cross-linked network, so that the waterproof grade is still greater than or equal to 90 after 30 times of water washing, the oil repellent grade is greater than or equal to 5, and the water contact angle and the oil contact angle are reduced by lt; the temperature is 5.5 DEG C, and the moisture permeability retention rate is gt; the antibacterial rate is 97%, and the antibacterial rate is gt; the compost degradation rate within 180 days is gt; 90%.

Description

Technical Field

[0001] This invention relates to the field of fabric technology, specifically to the preparation of a stain-resistant and waterproof polyester composite fabric. Background Technology

[0002] Polyester fabrics are widely used in outdoor clothing and protective textiles due to their high strength, abrasion resistance, and durability. With the upgrading of consumption and the popularization of environmental protection concepts, the market's functional requirements for polyester fabrics have gradually expanded from basic waterproofing to a comprehensive requirement of "waterproofing, breathability, multi-functional synergy, and environmental sustainability." In particular, the outdoor clothing sector has a particularly urgent need for a balance between water pressure resistance and moisture permeability, while protective equipment requires additional functions such as antibacterial and flame retardant properties, and home decor fabrics focus more on washability and environmental friendliness.

[0003] Based on research on polyester composite fabrics, the core of existing technologies not only focuses on the component design of waterproof and antibacterial polyester composite fabrics, but also pays attention to the abrasion resistance and tear resistance of the composite fabric. For example, CN222451589U discloses an abrasion-resistant polyester composite fabric, including an abrasion-resistant fabric layer and an antibacterial fabric layer. The abrasion-resistant fabric layer is woven from two-filament opposite-twist wrapped yarns, and the two-filament opposite-twist wrapped yarns include a core yarn and graphene-modified nylon filaments and polypropylene filaments spirally wrapped around the outside of the core yarn in opposite directions. This can effectively utilize the abrasion-resistant properties of nylon and polypropylene to improve the abrasion resistance of the polyester composite fabric. CN222495726U discloses a tear-resistant, waterproof, and breathable polyester-cotton composite fabric, consisting of a surface layer, a middle layer, and a middle layer. The fabric is composed of an interlayer and a base layer, layered sequentially. The surface layer has evenly spaced outward folds forming protrusions, on which elastic threads are threaded. Several breathable holes are located at the top. A waterproof and breathable membrane is placed between the interlayer and the surface layer. The base layer is woven from a polyester-cotton blend. The composite fabric, through the combination of the waterproof and breathable membrane and the interlayer, effectively improves its waterproof performance and significantly enhances its breathability. The protrusions and elastic threads on the surface layer prevent the fabric from breaking under tension, further improving its overall strength. Therefore, current technology focuses on increasing the abrasion resistance, tear resistance, breathability, and user comfort of polyester composite fabrics, while research on stain resistance, waterproofing, and subsequent environmentally friendly treatment of polyester composite fabrics remains lacking.

[0004] In summary, how to comprehensively utilize new materials and green processes to prepare polyester composite fabrics that combine stain resistance, water resistance, durability, multifunctionality, and environmental degradability has become an urgent technical problem to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing a stain-resistant and waterproof polyester composite fabric, so as to solve the problems of environmental protection, durability and functional expansion in the prior art.

[0006] The specific technical solution is as follows: A method for preparing a stain-resistant and waterproof polyester composite fabric, wherein the preparation of the polyester composite fabric requires the polyester base fabric to undergo processes such as dual-hydrophobic surface construction, bio-based cross-linking fixation, multifunctional thermoplastic polyurethane elastomer (TPU) film layer composite, and biodegradable structural design.

[0007] Furthermore, the polyester composite fabric includes a polyester base fabric, a layer of dual-repellent functional coating, a layer of copolyamide hot melt adhesive web (PA hot melt adhesive web) and a layer of modified TPU functional film.

[0008] Furthermore, the dual-hydrophobic surface construction involves constructing a hydrophobic and oleophobic coating with a micro / nano composite rough structure on the surface of the polyester base fabric.

[0009] Furthermore, the hydrophobic and oleophobic coating is achieved using a supercritical CO2-assisted process. This involves dispersing long-chain silanes and fluorinated graphene in a small amount of co-solvent, then forming a homogeneous or emulsion system with CO2 under high pressure. Subsequently, the pressure is rapidly reduced by controlling the valve, causing the dissolved coating components to precipitate on the fabric surface and form a micro-nano composite rough coating.

[0010] Furthermore, the bio-based crosslinking fixation replaces the traditional isocyanate crosslinking system by introducing a chitosan derivative-citric acid crosslinking network to generate a transparent and robust bio-based film that encapsulates and fixes the micro-nano composite rough coating.

[0011] Furthermore, the multifunctional TPU film layer composite is a modified TPU functional film laminated on the inner side of the polyester base fabric to achieve multifunctional integration such as antibacterial and antistatic properties.

[0012] Furthermore, the biodegradable structure design uses polybutylene adipate terephthalate copolymer (PBAT) and polylactic acid (PLA) blended with TPU to prepare the membrane material.

[0013] The preparation of a stain-resistant and waterproof polyester composite fabric includes the following steps: S1: 200D polyester filament woven fabric is selected as the base fabric. It is refined and cleaned to remove surface additives and impurities. After drying, the polyester fabric is placed in the high pressure vessel of the supercritical CO2 treatment device, with a 2-3mm gap between layers to form a radial channel. The support is a porous stainless steel cylinder.

[0014] S2: At room temperature, prepare the functional coating precursor solution by adding octadecyltriethoxysilane to anhydrous ethanol and stirring to form a homogeneous solution. Slowly add an appropriate amount of deionized water to promote partial hydrolysis of the silane. Then add fluorinated graphene (F-GO) nanosheets and ultrasonically disperse for 30 minutes to obtain a homogeneous suspension, i.e., the functional coating precursor solution. While stirring, inject the mixed suspension into an autoclave using a high-pressure pump, ensuring the suspension covers the fabric surface. Maintain the CO2 pressure in the autoclave at 12 MPa and the temperature at 40°C for 20 minutes to promote thorough mixing of the solute and CO2. After complete mixing, the solute diffuses and penetrates into the fiber surface and micropores along with the CO2. Subsequently, slowly reduce the pressure to release CO2, constructing a micro / nano composite rough coating. After treatment, remove the fabric and dry it at 80°C for 10 minutes to remove residual solvent.

[0015] S3: Prepare the crosslinking solution by taking quaternized chitosan, citric acid, sodium sulfate catalyst, vinyl-modified nano-SiO2, and deionized water. First, dissolve the citric acid in water, add the chitosan and stir until transparent, then add the catalyst and stir. Finally, add the vinyl-modified nano-SiO2, sonicate for 15 minutes, filter, and mature before use. Before use, adjust the pH of the solution to 4 with glacial acetic acid to improve the solubility of the chitosan quaternary ammonium salt. Immerse the fabric treated in S2 in the crosslinking solution and squeeze out the excess liquid, then pre-dry it in a forced-air oven. The pre-dried fabric is then transferred to a baking oven for baking, allowing the citric acid and chitosan derivatives to undergo a crosslinking reaction. After washing away unreacted chemicals, a transparent and firm bio-based film forms on the fabric surface, encapsulating and fixing the micro-nano composite rough coating in S2.

[0016] S4: A TPU functional film containing antibacterial and conductive components was prepared using a casting method. TPU particles, PBAT resin, and PLA resin were mixed and melted in a twin-screw extruder. After the polymer was uniformly melted, silver zeolite antibacterial microparticles and multi-walled carbon nanotubes were added, and the mixture was further melt-blended to ensure that the silver zeolite and carbon nanotubes were fully dispersed in the polymer matrix. The mixture was extruded through a T-die and calendered into a 50 μm thick film, i.e., the TPU functional film. After cooling, it was wound up for later use.

[0017] S5: PA hot melt adhesive mesh and TPU functional film are sequentially covered on the inner surface of the fabric. The TPU film is then hot-pressed for 30 seconds using a flatbed hot press to slightly melt and adhere to the fabric fiber surface. After cooling, a strong composite layer is formed. The outer layer is a polyester fabric layer treated with double hydrophobicity, and the inner layer is a functionalized TPU film layer. The interface between the two is bonded by hot melting to obtain the final product, a stain-resistant and waterproof polyester composite fabric.

[0018] Furthermore, the functional coating precursor liquid described in S2 is composed of 5 parts octadecyltriethoxysilane, 1 part fluorinated graphene nanosheets, and 94 parts anhydrous ethanol.

[0019] Furthermore, in the cross-linking solution described in S3, the ratio of chitosan to citric acid is 1:2, and the excess liquid is rolled off with a roll-off rate of 80%.

[0020] Furthermore, in the thermoplastic polyurethane elastomer functional film described in S4, the ratio of PBAT resin to PLA resin is 3:2.

[0021] Furthermore, the hot pressing described in S5 is performed at a temperature of 130°C, a pressure of 1 MPa, and a time of 30 seconds.

[0022] Furthermore, the polyester composite fabric described in S5 has a waterproof rating of ≥90, an oil repellency rating of ≥5, a water contact angle and an oil contact angle decrease of <5.5°, a moisture retention rate of >97%, an antibacterial rate of >95%, and a compost degradation rate of >90% after 180 days.

[0023] Compared with the prior art, the present invention has the following beneficial effects: (1) Superhydrophobic and oleophobic and fluorine-free and environmentally friendly: The dual hydrophobic coating constructed by plant-based silane and fluorinated graphene can achieve hydrophobic and oleophobic effects far exceeding those of traditional finishing, and does not use any perfluorinated or polyfluoroalkyl chemicals, thus avoiding the harm of perfluorinated and polyfluoroalkyl substances to the environment and human body.

[0024] (2) Excellent wash resistance: The chitosan-citric acid crosslinking network significantly enhances the bonding strength between the coating and the fiber, ensuring that the waterproof and stain-resistant properties are maintained even after multiple washes. The fabric of this invention maintains a water resistance rating of over 90 after 30 machine washes, significantly outperforming existing fluorine-free waterproof finishing methods in terms of wash resistance. Furthermore, the use of a bio-based crosslinking agent avoids the use of harmful substances such as isocyanates, making the production process safer.

[0025] (3) Green and low-carbon preparation process: The innovative use of supercritical CO2 as the processing medium enables the deposition of functional coatings without water or organic solvents, which basically eliminates the emission of volatile organic compounds and reduces energy consumption. This process is in line with the trend of clean production and carbon emission reduction, and has both economic and environmental benefits in industrial applications.

[0026] (4) Multifunctional integration: By introducing functional membrane layers, this fabric integrates efficient and broad-spectrum antibacterial properties and excellent antistatic properties, meeting the multiple needs of special scenarios for fabrics. This multifunctional integration is achieved through material addition and is completed in one step of the process without the need for additional finishing steps, ensuring the durability and uniformity of the function.

[0027] (5) Biodegradable and recyclable: The TPU film layer has biodegradability after being modified by blending PBAT and PLA. Under specific composting conditions, it can degrade more than 90%, which greatly alleviates the problem of disposal after the composite fabric is discarded. It meets the performance requirements while taking into account the ecological and environmental impact of the product. Attached Figure Description

[0028] Figure 1 This is a flowchart illustrating the preparation process of a stain-resistant and waterproof polyester composite fabric according to the present invention.

[0029] Figure 2 This is a structural diagram of a stain-resistant and waterproof polyester composite fabric according to the present invention.

[0030] Figure 3 This is a comparison chart of the experimental results of the comprehensive evaluation index in Experiment Example 1. Detailed Implementation

[0031] The following embodiments further explain and illustrate the technical solutions of the present invention. It should be specifically noted that each specific embodiment is a concretization and explanation of the technical solution and should not be considered as a limitation on the scope of protection of the present invention. Those skilled in the art still have the right to modify the technical solutions of these embodiments and make equivalent substitutions for some or all of the technical features, and these modifications or substitutions do not change the essence of the corresponding technical solutions, nor do they cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions described in the present invention.

[0032] The technical solution designed by this invention to solve the existing problems includes the following key points: 1. Construction of a dual-repellent functional coating Dual hydrophobicity, i.e., hydrophobicity + oleophobicity, is the core performance objective of coatings. Essentially, it involves reducing the surface energy of the substrate through "chemical modification + microstructure regulation," while simultaneously constructing a rough structure, ultimately resulting in a high contact angle and low roll-off angle for liquids on the surface. This invention selects low surface energy materials as the coating matrix, which are attached to the substrate surface through chemical grafting or physical deposition to reduce surface tension. By using nanoparticle doping, electrospinning to form micro / nano protrusions, or etching the substrate surface to create a porous structure, the single defect of being hydrophobic but oleophilic or oleophobic but hydrophilic is avoided.

[0033] 2. Supercritical CO2-assisted process Supercritical CO2 is a green solvent or reaction medium with a temperature >31.1℃ and pressure >7.38MPa. It can replace traditional organic solvents for the dissolution, dispersion, and interfacial bonding of coating raw materials with substrates, and is particularly suitable for heat-sensitive and easily degradable substrates. From a process principle perspective, the core advantage of supercritical CO2 lies in the entire process of "penetration-dissolution-deposition". The diffusion coefficient of supercritical CO2 is much higher than that of traditional organic solvents, allowing it to quickly penetrate into the tiny gaps inside the substrate, ensuring that the coating raw materials are uniformly dispersed on the surface and inside the substrate, avoiding problems such as uneven surface coverage and coating accumulation in traditional coating processes. In this invention, when preparing a dual-hydrophobic coating on the surface of polyester fabric, supercritical CO2 can carry the fluorocarbon coating raw materials to penetrate into the gaps between fibers, forming a fiber-encapsulated coating, rather than just forming a thin film on the fabric surface, significantly improving the durability of the coating.

[0034] 3. Chitosan derivative-citric acid crosslinking fixation Chitosan, a natural amino polysaccharide, possesses excellent antibacterial properties, biocompatibility, and biodegradability, making it an ideal raw material for functional coatings. However, pure chitosan has two major drawbacks: firstly, its poor water solubility leads to brittleness after film formation; secondly, its weak adhesion to the substrate makes it prone to detachment after washing or friction. Therefore, a stable three-dimensional network structure needs to be constructed through cross-linking reactions. Citric acid, as a polycarboxylic acid, is both a green and environmentally friendly cross-linking agent and can form multiple chemical bonds with chitosan and the substrate, becoming the key to solving this problem. From the perspective of the cross-linking mechanism, the reaction between citric acid and chitosan derivatives mainly involves two steps: the first step is the amidation reaction between the carboxyl groups of citric acid and the amino groups of the chitosan derivative. Under weakly acidic conditions, the amino groups of the chitosan derivative are protonated to form ammonium ions, which then undergo a condensation reaction with the carboxyl groups of citric acid to generate amide bonds. The second step is the esterification reaction between the remaining carboxyl groups of citric acid and the hydroxyl groups of chitosan or the hydroxyl groups on the surface of the substrate, forming ester bonds. These two chemical bonds together form a three-dimensional cross-linked network, which not only improves the mechanical properties of the chitosan coating, but also enhances its water resistance. In practical operation, this invention requires careful control of three key parameters: First, the degree of modification of the chitosan derivative. The degree of substitution of quaternized chitosan needs to be controlled between 60% and 80%. If the substitution is too low, the water solubility will be insufficient, making it difficult to form a uniform coating; if the substitution is too high, the number of amino groups will decrease, and the crosslinking efficiency will decline. Second, the amount of citric acid used. Typically, the mass ratio of citric acid to chitosan is 1:3 to 3:1. If the amount is too small, the crosslinking will be insufficient, and the coating will easily dissolve; if the amount is too large, it will lead to over-crosslinking of the coating, resulting in embrittlement and cracking. Third, the reaction conditions. The reaction temperature is generally 80-120℃. If the temperature is too low, the reaction rate will be slow; if the temperature is too high, chitosan will easily degrade, the molecular chains will break, and the antibacterial properties will decrease. The reaction time is usually 1-2 hours to ensure complete crosslinking and no byproducts are produced.

[0035] 4. Preparation and Composite of Functional Films Single-function coatings are insufficient to meet complex practical needs. Therefore, this invention integrates different functional membranes into a whole through the preparation and composite of functional membranes, becoming a core technology for improving the overall performance of coatings. From the perspective of membrane structure design, typical composite coatings usually adopt a three-layer architecture: the bottom layer is the adhesive layer, which enhances the adhesion between the coating and the substrate, and is usually made of a polymer with good compatibility with the substrate; the middle layer is the functional core layer, which integrates different functions according to requirements; and the top layer is the performance optimization layer.

[0036] In terms of composite processes, appropriate methods must be selected based on the characteristics of the film layers and the type of substrate. This invention employs a dry composite process, which is suitable for heat-sensitive films: each film layer is prefabricated, and then the film layers are bonded to the substrate through hot pressing, avoiding damage to the film layer function caused by high temperatures. The performance balance issue also needs to be addressed during the composite process. Through reasonable structural design and process control, the composite coating can achieve a "1+1>2" effect, meeting the needs of multiple scenarios.

[0037] 5. Biodegradable structural design The biodegradable design of the composite fabric in this invention is achieved through a three-in-one synergistic approach of "membrane-adhesive-fiber". The TPU functional membrane uses a biodegradable matrix of PBAT and PLA blend, which can disintegrate in 15 days under industrial composting conditions and has a biodegradation rate of ≥90% in 180 days. The PA hot melt adhesive web is a copolyamide containing PLA oligomers with a melting point of 105℃. During composting, the PLA microdomains hydrolyze first, followed by the attack of amide bonds by microorganisms, resulting in a weight loss rate of ≥85% for the adhesive layer. The chitosan-citric acid crosslinking layer breaks through both ester and amide bonds to generate oligosaccharides and citric acid, both of which can be directly metabolized by Aspergillus and Bacillus, with a weight loss rate of ≥92%. The inorganic functional particles use PBAT as a carrier or have a particle size ≤20nm, and after degradation, Ag... + Zn is reduced and fixed by humic acid. 2+ It enters the plant-usable zone and has no ecotoxicity. Overall, it meets the acceptable standards for industrial composting.

[0038] 6. Composition of polyester composite fabrics This invention places a double-repellent layer on the outermost layer of the fabric, forming the first protective barrier. This layer consists of fluorinated graphene deposited by supercritical CO2 and a C18 plant-derived silane nanocoating. The middle and outer layers are, in sequence, a PA hot-melt adhesive web and a TPU multifunctional film, forming a "repellent outer layer - adhesive middle layer - functional inner layer" sandwich structure. The outer layer preferentially blocks water, oil, and stains, reducing the consumption of the functional phase in the inner layer and extending overall durability. The inner layer provides antibacterial, antistatic, and biodegradable support, achieving gradient protection from the outside in. The outer double-repellent layer and the inner functional film are bonded together at low temperature using a hot-melt adhesive web, avoiding high-temperature damage and ensuring overall mechanical and degradation performance. This design ensures that stains and moisture are preferentially repelled on the outer layer, reducing the load on the inner layer, extending service life, while maintaining the overall lightweight, softness, and breathability of the fabric. Example

[0039] A method for preparing a stain-resistant and waterproof polyester composite fabric includes the following steps: S1: 200D polyester filament woven fabric was selected as the base fabric and subjected to refining and cleaning treatment. The polyester base fabric underwent a three-step cleaning process: 75℃ hot alkali refining, neutralization acid washing, and hot water washing, with a total time of 90 minutes. The final pH was determined to be 7, with no silicone oil residue. The treated polyester fabric was then wound onto the support inside the high-pressure vessel of the supercritical CO2 treatment device, with a 2-3mm gap between layers to form radial channels. The support was a porous stainless steel cylinder.

[0040] S2: At room temperature, prepare the functional coating precursor solution by adding 5 parts of octadecyltriethoxysilane to 94 parts of anhydrous ethanol and stirring to form a homogeneous solution. Slowly add an appropriate amount of deionized water to promote partial hydrolysis of the silane. Then add 1 part of F-GO nanosheets and ultrasonically disperse for 30 minutes to obtain a homogeneous suspension, i.e., the functional coating precursor solution. While stirring, inject the mixed suspension into an autoclave through a high-pressure pump, ensuring the suspension covers the fabric surface. Maintain the CO2 pressure in the autoclave at 12 MPa and the temperature at 40°C for 20 minutes to promote thorough mixing of the solute and CO2. After complete mixing, the solute diffuses and penetrates into the fiber surface and micropores along with the CO2. Subsequently, slowly reduce the pressure to release CO2, constructing a micro / nano composite rough coating. After treatment, remove the fabric and dry it at 80°C for 10 minutes to remove residual solvent.

[0041] S3: Prepare the crosslinking solution by taking 2 parts of 3 g / L quaternized chitosan, 4 parts of 10 g / L citric acid, 0.8 parts of 1 g / L sodium sulfate catalyst, 0.5 parts of vinyl-modified nano-SiO2, and 92.7 parts of deionized water. First, dissolve the citric acid in water, add the chitosan and stir until transparent, then add the catalyst and stir. Finally, add the vinyl-modified nano-SiO2, sonicate for 15 minutes, filter, and mature for later use. Adjust the pH of the solution to 4 using glacial acetic acid to improve the solubility of the chitosan quaternary ammonium salt. Immerse the fabric treated in S2 in the crosslinking solution for 1 minute, then roll off the excess liquid (80% residue). Pre-dry in a 110℃ forced-air oven for 2 minutes. The pre-dried fabric is then transferred to a 160℃ baking oven for 3 minutes to allow the citric acid and chitosan derivatives to crosslink. After washing away unreacted chemicals, a transparent and firm bio-based film forms on the fabric surface, encapsulating and fixing the micro-nano composite rough coating from S2.

[0042] S4: A TPU functional film containing antibacterial and conductive components was prepared using a casting method. 47 parts TPU granules, 30 parts PBAT resin, and 20 parts PLA resin were mixed and melted in a twin-screw extruder at a temperature of 180℃. After the polymer was uniformly melted, 2 parts silver zeolite antibacterial microparticles and 1 part multi-walled carbon nanotubes were added, and the mixture was further melt-mixed for 5 minutes to ensure thorough dispersion of the silver zeolite and carbon nanotubes in the polymer matrix. The mixture was extruded through a T-die and calendered into a 50μm thick film, i.e., the TPU functional film. After cooling, it was wound up for later use.

[0043] S5: PA hot melt adhesive web and TPU functional film are sequentially applied to the inner surface of the fabric. The mixture is then hot-pressed for 30 seconds at 130℃ and 1MPa using a flatbed hot press, causing the TPU film to slightly melt and adhere to the fabric fiber surface. After cooling, a strong composite layer is formed. The outer layer is a double-repellent treated polyester fabric layer, and the inner layer is a functionalized TPU film layer. The interface between the two is bonded by hot melting. This yields the final product: a stain-resistant and waterproof polyester composite fabric. Example

[0044] The preparation method is the same as in Example 1, except that: S2: Replace 5 parts of octadecyltrimethoxysilane with 3 parts of octadecyltrimethoxysilane and 94 parts of anhydrous ethanol with 96 parts of anhydrous ethanol; S3: Replace 2 parts of 3 g / L quaternized chitosan and 4 parts of 10 g / L citric acid with 2 parts of 3 g / L quaternized chitosan and 6 parts of 10 g / L citric acid; replace the 80% pick-up ratio with a 70% pick-up ratio. S4: Replace 47 parts TPU granules, 30 parts PBAT resin, and 20 parts PLA resin with 57 parts TPU granules, 20 parts PBAT resin, and 20 parts PLA resin. S5: Hot pressing for 30 seconds at 130℃ and 1MPa is replaced with hot pressing for 60 seconds at 120℃ and 1.5MPa.

[0045] All other steps are the same. Example

[0046] The preparation method is the same as in Example 1, except that: S2: 5 parts octadecyltrimethoxysilane were replaced with 7 parts octadecyltrimethoxysilane, and 94 parts anhydrous ethanol were replaced with 92 parts anhydrous ethanol; S3: Replace 2 parts of 3 g / L quaternized chitosan and 4 parts of 10 g / L citric acid with 6 parts of 3 g / L quaternized chitosan and 2 parts of 10 g / L citric acid; replace the 80% pick-up percentage with a 90% pick-up percentage. S4: Replace 47 parts TPU granules, 30 parts PBAT resin, and 20 parts PLA resin with 37 parts TPU granules, 40 parts PBAT resin, and 20 parts PLA resin. S5: Hot pressing at 130℃ and 1MPa for 30 seconds is replaced with hot pressing at 140℃ and 2MPa for 45 seconds.

[0047] All other steps are the same.

[0048] Comparative Example 1 The preparation method is the same as in Example 1, except that: S3: Finished with commercial fluorinated water-repellent agent, using 30g / L of C6 fluorocarbon emulsion finishing agent without crosslinking agent, padding the fabric, with a pick-up rate of 75%, and drying at 150℃ for 2 minutes.

[0049] All other steps are the same.

[0050] Comparative Example 2 The preparation method is the same as in Example 1, except that: S3: Crosslinking treatment omitted.

[0051] All other steps are the same.

[0052] Comparative Example 3 The preparation method is the same as in Example 1, except that: S4: Replace the TPU functional film with a pure TPU film that does not contain PBTA and PLA, nor does it contain silver zeolite or carbon nanotubes.

[0053] All other steps are the same.

[0054] Experimental Example 1 The polyester composite fabrics prepared in Examples 1-3 and Comparative Examples 1-3 were tested: (1) Waterproof rating: The test is conducted according to GB / T 4745-2012 "Test and evaluation of waterproof performance of textiles by water-drenching method". A 180mm×180mm sample is cut and fixed on the ring holder with the test surface facing upward at a 45° angle to the horizontal. 250mL of deionized water is sprayed evenly within 27~30s. The sample is compared with the standard water-drenching photo immediately after spraying. The polyester composite fabric is retested after 30 standard water washes. The rating is 0~100, and ≥90 is excellent.

[0055] (2) Oil repellency level: Refer to GB / T 19977-2014 "Textiles Oil Repellency and Hydrocarbon Resistance Test" for determination. Cut a 180mm×180mm sample, add 50µL to the sample surface, and observe whether the droplet wets or penetrates after 30s±2s. If the droplet remains spherical and does not wet, the level is valid and the next higher number is continued. If wetting, wicking or disappearance occurs, the level is invalid. The previous level number is taken as the oil repellency level. After 30 standard water washes, the polyester composite fabric is retested and the oil repellency level is 0~8.

[0056] (3) Static contact angle: The measurement is carried out in five steps: “sample preparation, liquid drop, imaging, fitting, and value taking”, referring to GB / T 30693-2014 “Measurement of contact angle between plastic film and water”.

[0057] (4) Antibacterial properties: The antibacterial activity value of the fabric against Staphylococcus aureus was determined with reference to GB / T 20944.3-2008 "Evaluation of antibacterial properties of textiles". The polyester composite fabric was tested at approximately 1×10 5 The bacterial suspension of CFU / ml was shaken and contacted for 24 hours before the colony count was determined.

[0058] (5) Antistatic performance: Surface resistance was measured according to GB / T 12703.4-2010 "Evaluation of Electrostatic Properties of Textiles". The test environment was 23±2℃ and relative humidity 50±5%. The polyester composite fabric was retested after 30 standard washes. Surface resistance 10 6 ~10 9 Ω indicates durability and antistatic properties.

[0059] (6) Moisture permeability: Refer to GB / T 12704.1-2009 "Textiles - Test Methods for Moisture Permeability - Part 1: Moisture Absorption Method" for moisture absorption method. The polyester composite fabric is sealed in a moisture permeation cup containing desiccant. The constant temperature and humidity environment is controlled. Water vapor is allowed to pass through the sample by utilizing the water vapor pressure difference inside and outside the cup. The mass change per unit time and per unit area is measured by weighing method, and the moisture permeability is calculated.

[0060] (7) Biodegradability: The biodegradability of materials was determined in accordance with GB / T 19277.1-2011 "Determination of final aerobic biodegradability of materials under controlled composting conditions by means of determination of carbon dioxide released - Part 1: General method". The sample was 50mm×50mm, and the composting was carried out at 58℃. The mass loss rate was ≥90% and the biodegradation rate was ≥90% within 180 days. The sample was judged to be completely compostable and degradable.

[0061] (8) Comprehensive evaluation index = 0.25 × waterproof rating + 0.20 × oil repellency rating + 0.15 × (10 - water Δθ) + 0.15 × (10 - oil Δθ) + 0.10 × (2 - resistance increase / decrease) + 0.05 × antibacterial rate + 0.05 × degradation rate + 0.05 × moisture permeability retention rate.

[0062] Table 1 Comparison of Experimental Results of Examples 1-3 Serial Number Testing items unit Example 1 Example 2 Example 3 1 Waterproof rating (30 washes) 1 92 90 94 2 Oil-repellent rating (30 washes) 1 6 5 6 3 <![CDATA[Water contact angle Δθ (θ 初始 - θ 30洗 )]]> ° 4.2 4.0 4.1 4 <![CDATA[Oil contact angle Δθ (θ 初始 - θ 30洗 )]]> ° 5.1 5.0 5.0 5 Resistance increase / decrease (30 washes / initial) Ω 1.34 1.29 1.41 6 Antibacterial rate (30 washes) % 96.37 95.12 97.03 7 Moisture permeability retention (30 washes / initial) % 0.98 0.97 0.99 8 Degradation rate (180 days) % 91.24 90.08 92.11 Table 2 Comparison of experimental results for Comparative Examples 1-3 Serial Number Testing items unit Comparative Example 1 Comparative Example 2 Comparative Example 3 1 Waterproof rating (30 washes) 1 85 72 91 2 Oil-repellent rating (30 washes) 1 4 3 6 3 <![CDATA[Water contact angle Δθ (θ 初始 -θ 30洗 )]]> ° 31.0 30.0 5.0 4 <![CDATA[Oil contact angle Δθ (θ 初始 - θ 30洗 )]]> ° 33.0 30.0 6.0 5 Resistance increase / decrease (30 washes / initial) Ω >1000× 2.67 >1000× 6 Antibacterial rate (30 washes) % 0 78.45 <50 7 Moisture permeability retention (30 washes / initial) % 0.96 0.97 0.98 8 Degradation rate (180 days) % <10 90.08 <5 Note: 10-water Δθ<0=0, 10-oil Δθ<0=0, resistance increase / decrease ≥10 times=0; antibacterial rate <50%=0, degradation rate <10%=5.

[0063] The comprehensive evaluation indices for Examples 1-3 and Comparative Examples 1-3 were calculated based on the comprehensive evaluation index content, and the results are as follows: Table 3 Comparison of Experimental Results of Comprehensive Evaluation Index in Experiment Example 1 experimental group Comprehensive evaluation index Example 1 94.06 Example 2 90.41 Example 3 92.78 Comparative Example 1 30.85 Comparative Example 2 48.27 Comparative Example 3 41.56 The experimental results of Examples 1-3 and Comparative Examples 1-3 are shown in Tables 1 and 2, and the calculated comprehensive evaluation index results are shown in Tables 3 and 4. Figure 3 As shown in Table 3 and Figure 3 It can be seen that Example 1 has the highest comprehensive evaluation index, which means that the comprehensive technical solution provided by Example 1 is the best implementation point, especially in terms of stain resistance and water resistance. As shown in Table 1, after 30 washes, its water resistance rating is ≥90, its oil repellency rating is ≥5, and its water contact angle and oil contact angle decrease by <5.5°.

[0064] As shown in Table 2, the oil repellency rating of Comparative Example 1 decreased from level 7 to level 4, and the contact angle decreased by >20°, proving that the fluorine-free + crosslinking scheme of Example 1 is significantly better than the traditional fluorine-containing finishing in terms of stain resistance and water resistance. Comparative Example 2 omitted chitosan-citric acid crosslinking, and after 30 water washes, the water resistance rating was only 72 and the oil repellency rating was 3, with a contact angle decrease of >30°, indicating that the nanostructured layer is easy to fall off without crosslinking, and the durability is unqualified.

[0065] As shown in Tables 1 and 2, the surface resistivity of Examples 1-3 remained stable within 0.5, with a change of less than one order of magnitude after 30 washes. In contrast, Comparative Example 3 exhibited excessively large resistivity fluctuations and an antibacterial rate of less than 50%, confirming that silver zeolite and carbon nanotubes are essential components for low resistivity and high antibacterial properties. All examples achieved a moisture retention rate ≥97%, indicating that the functional layer did not clog the pores, achieving a balance between waterproofing and breathability. The crosslinking layer and TPU membrane in Examples 1-3 all contain bio-based components, thus achieving an industrial compost degradation rate ≥90% after 180 days. Comparative Examples 1 and 3, lacking bio-based components, had degradation rates <10%, highlighting the ingenuity of the "membrane-adhesive-fiber" integrated biodegradable design of this invention.

[0066] In summary, Comparative Example 1 showed a significant decrease in oil repellency, an excessive increase in surface resistivity, and a degradation rate of <10%; Comparative Example 2 exhibited a sharp drop in durability; and Comparative Example 3 showed no antibacterial properties and was non-degradable. This invention, however, achieves integrated functions of durability, dual repellency, antibacterial properties, antistatic properties, and biodegradability through a three-in-one synergistic design of "membrane-adhesive-fiber." Example 1 utilizes supercritical CO2 deposition + F-GO and C18 silane dual repellency finishing, chitosan-citric acid crosslinking curing, combined with a TPU functional membrane and PA hot melt adhesive mesh, and undergoes one-step hot-pressing composite. After 30 water washes, its waterproof rating is 92, its oil repellency rating is 6, the decrease in water and oil contact angles is <5.5°, the increase in resistivity is <1.5, its antibacterial rate is >96%, its moisture retention rate is >97%, its 180-day compost degradation is >90%, and its comprehensive evaluation index is 94.06, significantly higher than the comparative examples. This invention, under the premise of being fluorine-free, formaldehyde-free, and free of volatile organic compounds, also takes into account durability, hydrophobicity and oleophobicity, permanent antistatic properties, high-efficiency antibacterial properties, and biodegradability for industrial composting.

Claims

1. A stain-resistant and waterproof polyester composite fabric, characterized in that, The polyester composite fabric consists of three layers: the outer layer is a polyester filament surface layer treated with fluorinated graphene and plant-derived C18 alkylsilane; the middle layer is a copolyamide hot melt adhesive web with a melting point of 105℃; and the inner layer is a biodegradable multifunctional thermoplastic polyurethane elastomer film loaded with silver zeolite antibacterial microcapsules and conductive carbon nanotubes.

2. The stain-resistant and waterproof polyester composite fabric as described in claim 1, characterized in that, The polyester filament surface layer is formed by using a supercritical CO2-assisted process on the surface of a polyester base fabric. Long-chain silanes and fluorinated graphene are dispersed in a small amount of co-solvent and then formed with CO2 under high pressure to form a homogeneous or emulsion system. Subsequently, the pressure is rapidly reduced by controlling the valve, causing the dissolved coating components to precipitate on the fabric surface and form a micro-nano composite rough coating.

3. The stain-resistant and waterproof polyester composite fabric as described in claim 2, characterized in that, The micro-nano composite rough coating needs to be placed in a crosslinking solution. After the citric acid and chitosan derivative in the crosslinking solution undergo a crosslinking reaction, a transparent and firm bio-based film is generated, which encapsulates and fixes the micro-nano composite rough coating.

4. The stain-resistant and waterproof polyester composite fabric as described in claim 1, characterized in that, The biodegradable multifunctional thermoplastic polyurethane elastomer film is a film material prepared by blending poly(butylene adipate-terephthalate) copolymer and polylactic acid with thermoplastic polyurethane elastomer to achieve multifunctional integration such as antibacterial and antistatic properties.

5. A method for preparing a stain-resistant and waterproof polyester composite fabric according to any one of claims 1 to 4, characterized in that, Includes the following steps: S1: Select polyester filament woven fabric as the base fabric, and refine and clean it to remove surface additives and impurities. After drying, wind the polyester fabric onto the support inside the high-pressure autoclave of the supercritical CO2 treatment device, leaving a gap of 2-3 mm between layers. S2: At room temperature, prepare the functional coating precursor solution by taking octadecyltriethoxysilane, adding it to anhydrous ethanol and stirring to form a uniform solution. Slowly add an appropriate amount of deionized water to promote partial hydrolysis of silane. Then add fluorinated graphene nanosheets and disperse them by ultrasonication for 30 minutes to obtain a uniform suspension, which is the functional coating precursor solution. Keep stirring and inject the mixed suspension into the autoclave through a high-pressure pump to completely immerse the polyester base fabric in the suspension. Adjust the CO2 pressure and temperature in the autoclave and maintain it for 20 minutes to promote the full mixing of solute and CO2. After complete mixing, slowly reduce the pressure to release CO2 and construct a micro-nano composite rough coating. After treatment, take out the fabric and dry it at 80°C for 10 minutes to remove residual solvent. S3: Prepare a crosslinking solution by taking quaternized chitosan, citric acid, sodium sulfate catalyst, vinyl-modified nano-SiO2 and deionized water. First, dissolve the citric acid in water, add the chitosan and stir until transparent, then add the catalyst and continue stirring. Finally, add the vinyl-modified nano-SiO2, sonicate for 15 minutes, filter, and mature for later use. Adjust the pH of the solution to 4 with glacial acetic acid. Then, immerse the fabric treated in S2 in the crosslinking solution and squeeze out the excess liquid. Place it in a forced-air drying oven for pre-drying. The pre-dried fabric is then transferred to a baking oven for baking to generate a transparent and firm bio-based film that coats and fixes the micro-nano composite rough coating in S2. S4: A thermoplastic polyurethane elastomer functional film containing antibacterial and conductive components is prepared by casting. Thermoplastic polyurethane elastomer particles, poly(butylene adipate-terephthalate) copolymer and polylactic acid are mixed and melted in a twin-screw extruder. After the polymer is melted uniformly, silver zeolite antibacterial microparticles and multi-walled carbon nanotubes are added and the mixture is melted and mixed. The mixture is then extruded through a T-die and calendered into a film, i.e., a thermoplastic polyurethane elastomer functional film. After cooling, it is wound up for later use. S5: Copolyamide hot melt adhesive web and thermoplastic polyurethane elastomer functional film are sequentially covered on the inner surface of the fabric. The thermoplastic polyurethane elastomer film is then hot-pressed using a flatbed hot press to slightly melt and adhere to the surface of the fabric fibers. After cooling, a strong composite layer is formed, which is a layered structure with inner and outer layers: the outer layer is a polyester fabric layer treated with double hydrophobicity, and the inner layer is a functionalized thermoplastic polyurethane elastomer film layer. The interface between the two is bonded by hot melting to obtain the final product, a stain-resistant and waterproof polyester composite fabric.

6. The method for preparing a stain-resistant and waterproof polyester composite fabric as described in claim 5, characterized in that, The functional coating precursor liquid described in S2 is composed of 3-7 parts of octadecyltriethoxysilane, 1 part of fluorinated graphene nanosheets, and 96-92 parts of anhydrous ethanol.

7. The method for preparing a stain-resistant and waterproof polyester composite fabric as described in claim 5, characterized in that, The cross-linking solution in S3 has a chitosan to citric acid ratio of 1:3 to 3:1, and the excess liquid is rolled off with a roll-off rate of 70 to 90%.

8. The method for preparing a stain-resistant and waterproof polyester composite fabric as described in claim 5, characterized in that, The thermoplastic polyurethane elastomer functional film described in S4 has a poly(butylene adipate-terephthalate) copolymer to polylactic acid ratio of 1:1 to 2:

1.

9. The method for preparing a stain-resistant and waterproof polyester composite fabric as described in claim 5, characterized in that, The hot pressing described in S5 has a temperature of 120~140℃, a pressure of 1.5~2Mpa, and a time of 45~60 seconds.

10. The method for preparing a stain-resistant and waterproof polyester composite fabric as described in claim 5, characterized in that, The polyester composite fabric described in S5 has a waterproof rating of ≥90, an oil repellency rating of ≥5, a water contact angle and an oil contact angle decrease of <5.5°, a moisture retention rate of >97%, an antibacterial rate of >95%, and a compost degradation rate of >90% after 180 days.

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