A water-washing-resistant color-changing antibacterial fabric and a preparation method thereof

Abstract

The application discloses a water-washing-resistant color-changing antibacterial fabric and a preparation method thereof. In the application, dynamic intelligent protection is realized through the synergistic linkage of various functional components. When the thermochromism is triggered by the change of human body temperature, the temperature-sensitive antibacterial component synchronously enhances the antibacterial effect. When the illumination environment changes, the photocatalytic assistant can accelerate the photochromic reaction and synergistically improve the photocatalytic antibacterial efficiency. A stable coating network is constructed by a multiple crosslinking system, which greatly improves the water-washing resistance. When the fabric contacts with weak acidic sweat, the pH-responsive antibacterial agent releases active components, and a double antibacterial defense line is formed with the quaternary phosphonium salt component, so that the fabric always maintains sensitive color-changing effect and persistent antibacterial protection ability after daily wearing and repeated washing, and meets the use requirements of various close-fitting clothes and outdoor clothes.

Description

Technical Field

[0001] This invention belongs to the field of fabric preparation technology, specifically a washable, color-changing, antibacterial fabric and its preparation method. Background Technology

[0002] Antibacterial fabrics are a class of functional textile materials made through specific processes or directly from antibacterial fibers. They aim to inhibit the growth and reproduction of bacteria, fungi, and other microorganisms on the fabric surface, preventing cross-infection and solving odor problems. Their antibacterial mechanisms are mainly divided into leaching and non-leaching types. The former destroys the cell membrane of microorganisms through slow-release chemical agents, while the latter uses grafting technology or nanomaterials (such as nano-silver and zinc oxide) to change the electrical properties or structure of the fiber surface, achieving active killing or inhibition of bacteria. Based on processing methods, antibacterial fabrics can be divided into virgin antibacterial fiber fabrics and finished antibacterial fabrics. The former embeds antibacterial agents into the fibers during the spinning stage, featuring washability and long-lasting effectiveness, while the latter adheres to the fabric surface through processes such as padding and coating. These fabrics are widely used in medical and health protective clothing, hotel and home textiles, sports and outdoor clothing, and underwear, significantly improving hygiene standards and effectively extending the lifespan of textiles. With increasing public health awareness and advancements in textile technology, antibacterial fabrics are developing towards broad-spectrum, high-efficiency, green, and multifunctional composites.

[0003] However, existing color-changing antibacterial fabrics generally suffer from weak cross-linking systems. After washing, the coating is easily peeled off, and functional components are severely lost, leading to a rapid decline in color-changing sensitivity and antibacterial performance. In most products, the color-changing and antibacterial functions operate independently, lacking a linkage mechanism for environmental response, and cannot dynamically enhance the antibacterial effect based on body temperature, light, or sweat. In some products, the functional components are unevenly dispersed, and the coating and substrate have insufficient adhesion, which not only affects performance stability but also leads to a decrease in the fabric's breathability, stiffness, and other wearing properties, making it difficult to meet the needs of repeated washing and long-term use. Summary of the Invention

[0004] The purpose of this invention is to provide a washable, color-changing, antibacterial fabric and its preparation method in order to solve the problems mentioned above.

[0005] The technical solution adopted in this invention is as follows: a washable color-changing antibacterial fabric, comprising: 100 parts by weight of modified polyester fiber fabric, 8-12 parts by weight of photochromic microcapsules, 5-8 parts by weight of thermochromic microcapsules, 2-3 parts by weight of cross-linking color-changing stabilizer, 4-6 parts by weight of quaternary phosphonium salt modified montmorillonite, 2-4 parts by weight of nano zinc oxide, 30-40 parts by weight of waterborne polyurethane emulsion, 1.5-2.5 parts by weight of aziridine cross-linking agent, 0.5-1 parts by weight of organosilicon leveling agent, 0.3-0.8 parts by weight of triethanolamine, 3-5 parts by weight of thermosensitive antibacterial reinforcing agent: poly(N-isopropylacrylamide) grafted chitosan, 2-3 parts by weight of titanium dioxide-doped bismuth vanadate photocatalytic color-changing aid, 1-2 parts by weight of cross-linking adhesion promoter isocyanate-based silane coupling agent, and 2-4 parts by weight of pH-responsive antibacterial sustained-release agent silver-loaded mesoporous silica.

[0006] In a preferred embodiment, a method for preparing a washable, color-changing, antibacterial fabric includes the following steps: S1: The polyester fiber fabric is subjected to alkali reduction and silanization pretreatment to introduce active groups on the fabric surface, providing sufficient reaction sites for the cross-linking and bonding of subsequent coatings, and ensuring the adhesion between the functional coating and the substrate.

[0007] S2: Mix photochromic microcapsules, thermochromic microcapsules, quaternary phosphonium salt modified montmorillonite, nano zinc oxide, thermosensitive antibacterial enhancer, photocatalytic color-changing agent, and pH-responsive antibacterial slow-release agent in proportion, add deionized water and stir at high speed for pre-dispersion treatment to ensure that each functional component is evenly dispersed, avoid agglomeration when mixed with film-forming agent in the later stage, and ensure the uniformity of coating function.

[0008] S3: Pour the waterborne polyurethane emulsion into the reactor, add triethanolamine to adjust the pH of the system to a suitable range, and then slowly and uniformly add the pre-dispersed functional component slurry, stirring and mixing at low speed throughout the process to allow the film-forming agent and each functional component to fully impregnate and coat, laying the foundation for the stability of the subsequent coating.

[0009] S4: Add aziridine crosslinking agent, crosslinking adhesion promoter, and silicone leveling agent to the uniformly mixed system, and continue stirring for 30 minutes to allow the crosslinking agent to react initially with the functional groups of waterborne polyurethane, while allowing the adhesion promoter to adapt to the active groups on the surface of the pretreated fabric in advance, thereby enhancing the subsequent crosslinking effect.

[0010] S5: Fix the pretreated polyester fiber fabric onto the unwinding device of the doctor blade coating equipment, start the equipment to evenly coat the prepared functional coating paste onto the fabric surface, precisely control the coating thickness, and ensure that the coating paste and the active groups on the fabric surface are in full contact, creating conditions for the subsequent crosslinking reaction.

[0011] S6: Place the coated fabric into a pre-drying oven and pre-dry it at 100℃ for 3 minutes to allow the moisture in the coating to evaporate quickly, promote the initial cross-linking of the cross-linking agent with the active groups of the fabric and the film-forming agent, and avoid coating sagging or component migration during subsequent high-temperature curing.

[0012] S7: The pre-dried fabric is placed in a high-temperature curing oven and heated to 150°C for 2 minutes to allow the cross-linking system to fully react and build a three-dimensional cross-linking network of substrate, coating and functional components, which greatly improves the wash resistance and functional stability of the fabric.

[0013] S8: The cured fabric is placed in 100℃ hot water for washing to remove uncrosslinked free components on the fabric surface. Then it is taken out and air-dried naturally to complete the preparation of the wash-resistant color-changing antibacterial fabric. Subsequently, comprehensive testing and verification can be carried out on the fabric's color-changing sensitivity, antibacterial performance and wash fastness.

[0014] In a preferred embodiment, in step S1, the polyester fiber fabric is completely immersed in a 20 g / L sodium hydroxide solution and kept at 95°C for 45 minutes, with gentle stirring every 10 minutes to ensure complete hydrolysis of the polyester molecules on the fabric surface. After treatment, the fabric is removed and rinsed repeatedly with running water until neutral, then immersed in a 5 g / L γ-aminopropyltriethoxysilane solution and left to soak at 30°C for 2 hours to allow the silane reagent to fully react with the hydroxyl groups on the fabric surface and introduce amino active groups. Finally, the fabric is removed and placed in an 80°C hot air circulating oven to dry for 30 minutes to thoroughly remove residual moisture and unreacted silane reagent from the fabric surface, providing sufficient active sites for the cross-linking of the functional coating in subsequent steps and preventing the coating from peeling off or delaminating after curing.

[0015] In a preferred embodiment, in step S2, photochromic microcapsules, thermochromic microcapsules, quaternary phosphonium salt-modified montmorillonite, nano zinc oxide, thermosensitive antibacterial enhancer, photocatalytic color-changing aid, and pH-responsive antibacterial sustained-release agent are weighed sequentially according to the formula ratio. All components are added to a dispersion tank containing deionized water, with the amount of deionized water being three times the total mass of the functional components. The high-speed stirring device of the dispersion tank is started, and the speed is adjusted to 1200 rpm, and stirring is continued for 45 minutes. During the stirring process, the temperature inside the dispersion tank is controlled not to exceed 35°C to prevent the microcapsule structure from being damaged by high temperature. After stirring is completed, the dispersion is filtered through a 100-mesh filter to remove incompletely dispersed agglomerated particles, ensuring that the components are uniformly dispersed when mixed with waterborne polyurethane in the subsequent process, and avoiding spots with uneven function in the coating.

[0016] In a preferred embodiment, in step S3, the formulated amount of aqueous polyurethane emulsion is poured into a reactor equipped with a heating jacket. The low-speed stirring device of the reactor is started, and the speed is adjusted to 300 rpm. Simultaneously, constant temperature water at 30°C is circulated through the jacket to maintain a stable temperature inside the reactor. Triethanolamine is slowly added dropwise to the reactor to adjust the pH value of the system to between 8 and 9, ensuring that the aqueous polyurethane is in a stable dispersion state. Subsequently, the filtered functional component dispersion is added uniformly at a rate of 50 ml per minute, while maintaining low-speed stirring throughout the process for 60 minutes. This allows the aqueous polyurethane molecules to fully encapsulate each functional component particle, forming a stable coating slurry system and providing a uniform functional coating raw material for subsequent coating steps.

[0017] In a preferred embodiment, in step S4, the prescribed amount of crosslinking adhesion promoter is first added to the reactor, and stirring is continued for 10 minutes to allow the active groups of the adhesion promoter to initially react with the terminal hydroxyl groups of the waterborne polyurethane, while simultaneously adapting the amino active groups on the surface of the pretreated fabric. Next, the prescribed amount of aziridine crosslinking agent is added, and the stirring speed is adjusted to 400 rpm, stirring for 15 minutes to allow the crosslinking agent to fully contact the carboxyl and hydroxyl groups of the waterborne polyurethane, resulting in a preliminary crosslinking reaction. Finally, the prescribed amount of silicone leveling agent is added, and stirring is continued for 5 minutes to adjust the leveling properties of the coating slurry, preventing pinholes or sagging during subsequent coating. Throughout the process, the temperature inside the reactor is maintained at 30°C to ensure the stability of the reactions of each component.

[0018] In a preferred embodiment, in step S5, the pretreated polyester fiber fabric is fixed on the unwinding device of the doctor blade coating equipment, and the unwinding tension is adjusted to 15N to ensure the fabric is flat and wrinkle-free. The doctor blade gap is adjusted to 150 micrometers, the fabric feeding speed is set to 5 meters per minute, and the coating equipment is started to uniformly coat the prepared functional coating paste in the reactor onto the fabric surface, controlling the dry weight of the coating to be 30 grams per square meter. During the coating process, the coating thickness is monitored in real time to ensure that the coating is uniform on both sides of the fabric, allowing the coating paste to fully penetrate the fiber gaps on the fabric surface and make close contact with the active groups introduced in the pretreatment, creating favorable conditions for the crosslinking reaction in the subsequent curing step.

[0019] In a preferred embodiment, in step S6, the coated fabric is placed in a pre-drying oven, with the oven temperature set to 100°C and the hot air velocity at 1.5 meters per second. The fabric's running speed within the oven is consistent with the coating speed, and the pre-drying time is maintained for 3 minutes. During the pre-drying process, the moisture in the coating slurry evaporates rapidly, and the aziridine crosslinking agent undergoes a preliminary crosslinking reaction with the amino active groups and functional groups of the waterborne polyurethane on the fabric surface. This temporarily fixes the functional coating on the fabric surface, preventing coating sagging or functional component migration during subsequent high-temperature curing, while ensuring a smooth, bubble-free coating surface.

[0020] In a preferred embodiment, in step S7, the pre-dried fabric is placed in a high-temperature curing oven. The oven is set to a heating rate of 10°C per minute, gradually increasing to 150°C and maintaining the temperature for 2 minutes. The oven uses a symmetrical hot air circulation method to ensure uniform temperature across all parts of the fabric. Under high-temperature conditions, the aziridine crosslinking agent fully exerts its effect, undergoing a comprehensive crosslinking reaction with waterborne polyurethane, adhesion promoter, and active groups on the fabric surface. This constructs a three-dimensional crosslinked network structure of substrate-coating-functional components, significantly improving the fabric's wash resistance and functional stability. The fabric can withstand more than 50 washes, and the retention rate of color change and antibacterial functions exceeds 85%.

[0021] In a preferred embodiment, in step S8, the cured fabric is placed in a washing tank containing hot water at 100°C, with a liquor ratio controlled at 1:20. The fabric is gently stirred and washed for 10 minutes to remove uncrosslinked free components and residual small molecules from the fabric surface. After washing, the fabric is removed and rinsed with running cold water to room temperature. It is then hung in a well-ventilated environment at 25°C and 60% relative humidity to air dry naturally for 24 hours, ensuring the fabric is completely dry and free of moisture residue.

[0022] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: In this invention, dynamic intelligent protection is achieved through the synergistic interaction of multiple functional components. When changes in body temperature trigger thermochromic reactions, the thermosensitive antibacterial component simultaneously enhances the antibacterial effect. When the light environment changes, the photocatalytic additive can both accelerate the photochromic reaction and synergistically improve the photocatalytic antibacterial efficiency. The multi-crosslinking system constructs a stable coating network, significantly improving the washability. At the same time, when in contact with weakly acidic sweat, the pH-responsive antibacterial agent releases active ingredients, forming a dual antibacterial defense with the quaternary phosphonium salt component. This allows the fabric to maintain a sensitive color-changing effect and long-lasting antibacterial protection capability after daily wear and repeated washing, meeting the usage needs of various underwear and outdoor clothing. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram comparing the water resistance performance over multiple cycles in this invention; Figure 3 This is a schematic diagram showing a comprehensive comparison of the color-changing performance in this invention. Figure 4 This is a schematic diagram comparing the static and dynamic antibacterial properties of the present invention; Figure 5 This is a schematic diagram comparing the mechanical properties and wearability of the invention. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0025] Reference Figure 1-5 A washable, color-changing antibacterial fabric comprises: 100 parts by weight of modified polyester fiber fabric, 8-12 parts by weight of photochromic microcapsules, 5-8 parts by weight of thermochromic microcapsules, 2-3 parts by weight of cross-linking color-changing stabilizer, 4-6 parts by weight of quaternary phosphonium salt modified montmorillonite, 2-4 parts by weight of nano zinc oxide, 30-40 parts by weight of waterborne polyurethane emulsion, 1.5-2.5 parts by weight of aziridine cross-linking agent, 0.5-1 parts by weight of organosilicon leveling agent, 0.3-0.8 parts by weight of triethanolamine, 3-5 parts by weight of thermosensitive antibacterial reinforcing agent: poly(N-isopropylacrylamide) grafted chitosan, 2-3 parts by weight of titanium dioxide-doped bismuth vanadate photocatalytic color-changing aid, 1-2 parts by weight of cross-linking adhesion promoter isocyanate-based silane coupling agent, and 2-4 parts by weight of pH-responsive antibacterial sustained-release agent silver-loaded mesoporous silica.

[0026] A method for preparing a washable, color-changing, antibacterial fabric includes the following steps: S1: The polyester fiber fabric is subjected to alkali reduction and silanization pretreatment to introduce active groups on the fabric surface, providing sufficient reaction sites for the cross-linking and bonding of the subsequent coating, and ensuring the adhesion between the functional coating and the substrate.

[0027] S2: Mix photochromic microcapsules, thermochromic microcapsules, quaternary phosphonium salt modified montmorillonite, nano zinc oxide, thermosensitive antibacterial enhancer, photocatalytic color-changing agent, and pH-responsive antibacterial slow-release agent in proportion, add deionized water and stir at high speed for pre-dispersion treatment to ensure uniform dispersion of each functional component, avoid agglomeration when mixed with film-forming agent in the later stage, and ensure uniformity of coating function.

[0028] S3: Pour the waterborne polyurethane emulsion into the reactor, add triethanolamine to adjust the pH of the system to a suitable range, and then slowly and uniformly add the pre-dispersed functional component slurry, stirring and mixing at low speed throughout the process to allow the film-forming agent and each functional component to fully impregnate and coat, laying the foundation for the stability of the subsequent coating.

[0029] S4: Add aziridine crosslinking agent, crosslinking adhesion promoter, and silicone leveling agent to the uniformly mixed system, and continue stirring for 30 minutes to allow the crosslinking agent to react initially with the functional groups of waterborne polyurethane, while allowing the adhesion promoter to adapt to the active groups on the surface of the pretreated fabric in advance, thereby enhancing the subsequent crosslinking effect.

[0030] S5: Fix the pretreated polyester fiber fabric onto the unwinding device of the doctor blade coating equipment, start the equipment to evenly coat the prepared functional coating paste onto the fabric surface, precisely control the coating thickness, and ensure that the coating paste and the active groups on the fabric surface are in full contact, creating conditions for the subsequent crosslinking reaction.

[0031] S6: Place the coated fabric into a pre-drying oven and pre-dry it at 100℃ for 3 minutes to allow the moisture in the coating to evaporate quickly, promote the initial cross-linking of the cross-linking agent with the active groups of the fabric and the film-forming agent, and avoid coating sagging or component migration during subsequent high-temperature curing.

[0032] S7: The pre-dried fabric is placed in a high-temperature curing oven and heated to 150°C for 2 minutes to allow the cross-linking system to fully react and build a three-dimensional cross-linking network of substrate, coating and functional components, which greatly improves the wash resistance and functional stability of the fabric.

[0033] S8: The cured fabric is placed in 100℃ hot water for washing to remove uncrosslinked free components on the fabric surface. Then it is taken out and air-dried naturally to complete the preparation of the wash-resistant color-changing antibacterial fabric. Subsequently, comprehensive testing and verification can be carried out on the fabric's color-changing sensitivity, antibacterial performance and wash fastness.

[0034] In step S1, the polyester fiber fabric is completely immersed in a 20 g / L sodium hydroxide solution and kept at 95°C for 45 minutes, with gentle stirring every 10 minutes to ensure complete hydrolysis of the polyester molecules on the fabric surface. After treatment, the fabric is removed and rinsed repeatedly with running water until neutral. It is then immersed in a 5 g / L γ-aminopropyltriethoxysilane solution and left to soak at 30°C for 2 hours, allowing the silane reagent to fully react with the hydroxyl groups on the fabric surface and introduce amino active groups. Finally, the fabric is removed and placed in an 80°C hot air circulating oven to dry for 30 minutes, thoroughly removing residual moisture and unreacted silane reagent from the fabric surface. This provides sufficient active sites for the cross-linking of the functional coating in subsequent steps and prevents the coating from peeling or delaminating after curing.

[0035] In step S2, the photochromic microcapsules, thermochromic microcapsules, quaternary phosphonium salt-modified montmorillonite, nano zinc oxide, thermosensitive antibacterial enhancer, photocatalytic color-changing aid, and pH-responsive antibacterial sustained-release agent are weighed sequentially according to the formula ratio. All components are added to a dispersion tank containing deionized water, with the amount of deionized water being three times the total mass of the functional components. The high-speed stirring device of the dispersion tank is started, and the speed is adjusted to 1200 rpm. Stirring is continued for 45 minutes, and the temperature inside the dispersion tank is controlled not to exceed 35°C during stirring to prevent the microcapsule structure from being damaged by high temperature. After stirring is completed, the dispersion is filtered through a 100-mesh filter to remove incompletely dispersed agglomerated particles, ensuring that the components are evenly dispersed when mixed with waterborne polyurethane in the subsequent process, and avoiding spots with uneven function in the coating.

[0036] In step S3, the formulated amount of aqueous polyurethane emulsion is poured into a reactor equipped with a heating jacket. The low-speed stirring device of the reactor is started, and the speed is adjusted to 300 rpm. At the same time, constant temperature water at 30°C is circulated through the jacket to maintain a stable temperature inside the reactor. Triethanolamine is slowly added dropwise to the reactor to adjust the pH value of the system to between 8 and 9, ensuring that the aqueous polyurethane is in a stable dispersion state. Subsequently, the filtered functional component dispersion is added at a uniform rate of 50 ml per minute, while maintaining low-speed stirring throughout the process for 60 minutes. This allows the aqueous polyurethane molecules to fully encapsulate each functional component particle, forming a stable coating slurry system and providing a uniform functional coating raw material for subsequent coating steps.

[0037] In step S4, the prescribed amount of crosslinking adhesion promoter is first added to the reactor, and stirring is continued for 10 minutes to allow the active groups of the adhesion promoter to react initially with the terminal hydroxyl groups of the waterborne polyurethane, while simultaneously adapting the amino active groups on the surface of the pretreated fabric. Next, the prescribed amount of aziridine crosslinking agent is added, and the stirring speed is adjusted to 400 rpm, stirring for 15 minutes to allow the crosslinking agent to fully contact the carboxyl and hydroxyl groups of the waterborne polyurethane, resulting in a preliminary crosslinking reaction. Finally, the prescribed amount of silicone leveling agent is added, and stirring is continued for 5 minutes to adjust the leveling properties of the coating slurry, preventing pinholes or sagging during subsequent coating. Throughout the process, the temperature inside the reactor is maintained at 30°C to ensure the stability of the reactions of each component.

[0038] In step S5, the pretreated polyester fiber fabric is fixed on the unwinding device of the doctor blade coating equipment, and the unwinding tension is adjusted to 15N to ensure the fabric is flat and wrinkle-free. The doctor blade gap is adjusted to 150 micrometers, the fabric feeding speed is set to 5 meters per minute, and the coating equipment is started. The prepared functional coating paste in the reactor is evenly applied to the fabric surface, and the dry weight of the coating is controlled to be 30 grams per square meter. The coating thickness is monitored in real time during the coating process to ensure that the coating is uniform on both sides of the fabric, allowing the coating paste to fully penetrate the fiber gaps on the fabric surface and make close contact with the active groups introduced in the pretreatment, creating favorable conditions for the crosslinking reaction in the subsequent curing step.

[0039] In step S6, the coated fabric is placed in a pre-drying oven. The oven temperature is set to 100°C, and the hot air velocity is 1.5 meters per second. The fabric's running speed within the oven is consistent with the coating speed, and the pre-drying time is maintained for 3 minutes. During the pre-drying process, the moisture in the coating slurry evaporates rapidly, and the aziridine crosslinking agent undergoes a preliminary crosslinking reaction with the amino active groups and functional groups of the waterborne polyurethane on the fabric surface. This temporarily fixes the functional coating on the fabric surface, preventing coating sagging or functional component migration during subsequent high-temperature curing, while also ensuring a smooth, bubble-free coating surface.

[0040] In step S7, the pre-dried fabric is placed in a high-temperature curing oven. The oven is set to a heating rate of 10°C per minute, gradually increasing to 150°C and maintaining the temperature for 2 minutes. The oven uses a symmetrical hot air circulation method to ensure uniform temperature across all parts of the fabric. Under high-temperature conditions, the aziridine crosslinking agent fully exerts its effect, undergoing a comprehensive crosslinking reaction with waterborne polyurethane, adhesion promoter, and active groups on the fabric surface. This constructs a three-dimensional crosslinked network structure of substrate-coating-functional components, significantly improving the fabric's wash resistance and functional stability. The fabric can withstand more than 50 washes, and the retention rate of color change and antibacterial functions exceeds 85%.

[0041] In step S8, the cured fabric is placed in a washing tank containing 100°C hot water at a liquor ratio of 1:20. The fabric is gently stirred and washed for 10 minutes to remove uncrosslinked free components and residual small molecules from the fabric surface. After washing, the fabric is removed and rinsed with running cold water until it reaches room temperature. It is then hung in a well-ventilated environment at 25°C and 60% relative humidity to air dry naturally for 24 hours, ensuring the fabric is completely dry and free of moisture.

[0042] Comparative Example 1: Preparation of color-changing antibacterial fabric without aziridine crosslinking agent: The method includes the following detailed steps: S1: Completely immerse the polyester fiber fabric in a 20 g / L sodium hydroxide solution and maintain the temperature at 95°C for 45 minutes, stirring every 10 minutes. After removal, rinse with running water until neutral. Subsequently, immerse the fabric in a 5 g / L γ-aminopropyltriethoxysilane solution and let it stand at 30°C for 2 hours. After removal, place it in an 80°C hot air circulating oven and dry for 30 minutes to complete the pretreatment.

[0043] S2: Weigh out the photochromic microcapsules, thermochromic microcapsules, quaternary phosphonium salt modified montmorillonite, nano zinc oxide, thermosensitive antibacterial enhancer, photocatalytic color-changing aid, and pH-responsive antibacterial sustained-release agent. Add three times the total mass of deionized water, start the high-speed stirring device and adjust the speed to 1200 rpm, and stir continuously for 45 minutes, controlling the temperature not to exceed 35℃. After stirring, filter through a 100-mesh filter.

[0044] S3: Pour the aqueous polyurethane emulsion into a reactor with a heating jacket, start a low-speed stirrer at 300 rpm, circulate 30°C constant temperature water to maintain the temperature, add triethanolamine dropwise to adjust the pH value to 8-9, then add the filtered functional dispersion at a rate of 50 ml per minute, and continue stirring for 60 minutes.

[0045] S4: Add cross-linking adhesion promoter and silicone leveling agent to the reactor, adjust the speed to 400 rpm, stir for 30 minutes to ensure that all components are mixed evenly.

[0046] S5: Fix the pretreated fabric to the doctor blade coating equipment, adjust the unwinding tension to 15N, the doctor blade gap to 150 micrometers, and the fabric feeding speed to 5 meters per minute. Start the equipment to evenly coat the coating paste onto the fabric surface, and control the dry weight of the coating to 30 grams per square meter.

[0047] S6: Place the coated fabric into a pre-drying oven, set to 100℃ hot air speed of 1.5 m / s, and pre-dry for 3 minutes to allow the coating moisture to evaporate and be initially fixed.

[0048] S7: Send the pre-dried fabric into a high-temperature curing oven, heat it to 150°C at a rate of 10°C per minute, maintain the curing time for 2 minutes, and use symmetrical hot air circulation to ensure uniform temperature.

[0049] S8: Place the cured fabric in a 100℃ hot water bath with a bath ratio of 1:20 and stir for 10 minutes. Remove and rinse with cold water to room temperature. Let it air dry naturally for 24 hours at 25℃ and 60% relative humidity.

[0050] Comparative Example 2: Preparation of color-changing antibacterial fabric without temperature-sensitive and pH-responsive antibacterial linkage components: The method includes the following detailed steps: S1: The operation is completely consistent with the original S1 example, and the polyester fiber fabric is subjected to alkali reduction and silanization pretreatment to introduce amino active groups.

[0051] S2: Weigh out the photochromic microcapsules, thermochromic microcapsules, quaternary phosphonium salt modified montmorillonite, nano zinc oxide, and photocatalytic color-changing additive, add 3 times the total mass of deionized water, start the high-speed stirring device and adjust the speed to 1200 rpm, stir continuously for 45 minutes, and control the temperature not to exceed 35℃. After stirring, filter with a 100-mesh filter.

[0052] S3: Pour the aqueous polyurethane emulsion into a reactor with a heating jacket, start a low-speed stirrer at 300 rpm, circulate 30°C constant temperature water to maintain the temperature, add triethanolamine dropwise to adjust the pH value to 8-9, then add the filtered functional dispersion at a rate of 50 ml per minute, and continue stirring for 60 minutes.

[0053] S4: Add aziridine crosslinking agent, crosslinking adhesion promoter, and organosilicon leveling agent to the reactor, adjust the speed to 400 rpm, and stir for 30 minutes to allow the crosslinking agent to fully react with the waterborne polyurethane functional groups.

[0054] S5: Fix the pretreated fabric to the doctor blade coating equipment, adjust the unwinding tension to 15N, the doctor blade gap to 150 micrometers, and the fabric feeding speed to 5 meters per minute. Start the equipment to evenly coat the coating paste onto the fabric surface, and control the dry weight of the coating to 30 grams per square meter.

[0055] S6: Place the coated fabric into a pre-drying oven, heat it with hot air at 100℃ and a wind speed of 1.5 meters per second for 3 minutes to promote the initial combination of the crosslinking agent and the active groups of the fabric.

[0056] S7: Place the pre-dried fabric into a high-temperature curing oven, heat it to 150°C at a rate of 10°C per minute, and maintain the curing time for 2 minutes to build a stable cross-linked network structure.

[0057] S8: Place the cured fabric in a 100℃ hot water bath with a bath ratio of 1:20 and stir for 10 minutes. Remove and rinse with cold water to room temperature. Let it air dry naturally for 24 hours at 25℃ and 60% relative humidity.

[0058] Comparative data analysis: Water wash resistance: The original embodiment, with its three-dimensional cross-linked network constructed by the aziridine cross-linking agent, exhibited coating adhesion and stability far exceeding those of Comparative Example 1, which lacked a cross-linking agent. Even after 50 washes, the coating retention rate, discoloration, and antibacterial properties remained at a high level. Comparative Example 2, lacking functionally linked antibacterial components, showed a significantly lower antibacterial performance retention rate after washing compared to the original embodiment.

[0059] Color-changing performance: The original embodiment has a faster color-changing response speed, shorter fading and recovery time, higher color retention rate after repeated use, and better rubbing fastness; Comparative Example 1 has a serious decline in color-changing performance due to easy coating peeling, and Comparative Example 2 has slightly inferior color-changing cycle stability compared to the original embodiment due to the lack of photocatalytic color-changing additives.

[0060] Antibacterial properties: The initial static antibacterial rates of the three were not significantly different, but the original embodiment had a dynamic response mechanism. When exposed to body temperature, light, or sweat, the antibacterial rate would actively increase. Moreover, after 50 washes, the antibacterial performance retention rate was much higher than that of the two comparative embodiments, demonstrating the synergistic effect of functional linkage components and cross-linking system.

[0061] Wearability: The original embodiment retains the mechanical properties and breathability of the original polyester fabric to the greatest extent while maintaining the coating function, and has moderate stiffness, making it suitable for making various garments; Comparative Example 1 has significantly reduced mechanical properties and wearability due to coating peeling off, while the performance of Comparative Example 2 is between that of the original embodiment and Comparative Example 1.

[0062] From the above, we can conclude that: This invention achieves a deep synergy between color response and antibacterial protection. During daily wear, the fabric exhibits corresponding color changes when the wearer's body temperature changes or when exposed to different lighting environments, simultaneously triggering the antibacterial protection mechanism. Whether it's thermochromic changes caused by increased body temperature or photochromic changes caused by changes in light, the corresponding antibacterial components work in tandem, allowing the fabric to not only have a visually appealing color change effect but also automatically enhance its antibacterial protection capabilities in different scenarios. The construction of a multi-crosslinking system ensures that the functional components are firmly attached to the fabric surface, maintaining stable color-changing sensitivity and antibacterial properties even after daily washing, without concern for functional loss. It is suitable for making various types of underwear, outdoor clothing, and children's products, providing wearers with continuous dynamic protection.

[0063] In this invention, every step from substrate pretreatment to the final product is closely interconnected. Pretreatment lays the foundation for coating adhesion, pre-dispersion ensures uniform distribution of functional components, step-by-step mixing allows the film-forming agent and functional components to fully integrate, and segmented pre-baking and high-temperature curing processes prevent coating sagging and ensure sufficient cross-linking reaction. Finally, water washing removes free components, further enhancing the fabric's safety. The entire preparation process uses a water-based system, which is environmentally friendly and production-friendly. The parameter settings of each step are coordinated to ensure the functional stability of the fabric and suitability for large-scale industrial production. It can be widely used in fields with high requirements for functionality and durability, such as medical and nursing clothing and sportswear, providing a reliable solution for fabric applications in different scenarios.

[0064] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the term "comprising" or any other variations thereof is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0065] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A washable, color-changing, antibacterial fabric, characterized in that: include: 100 parts by weight of modified polyester fiber fabric, 8-12 parts by weight of photochromic microcapsules, 5-8 parts by weight of thermochromic microcapsules, 2-3 parts by weight of cross-linking color-changing stabilizer, 4-6 parts by weight of quaternary phosphonium salt modified montmorillonite, 2-4 parts by weight of nano zinc oxide, 30-40 parts by weight of waterborne polyurethane emulsion, 1.5-2.5 parts by weight of aziridine cross-linking agent, 0.5-1 parts by weight of organosilicon leveling agent, 0.3-0.8 parts by weight of triethanolamine, 3-5 parts by weight of thermosensitive antibacterial reinforcing agent: poly(N-isopropylacrylamide) grafted chitosan, 2-3 parts by weight of titanium dioxide doped bismuth vanadate photocatalytic color-changing aid, 1-2 parts by weight of cross-linking adhesion promoter isocyanate-based silane coupling agent, and 2-4 parts by weight of pH-responsive antibacterial sustained-release agent silver-supported mesoporous silica.

2. The method for preparing a washable, color-changing, antibacterial fabric as described in claim 1, characterized in that: The method includes the following steps: S1: The polyester fiber fabric is subjected to alkali reduction and silanization pretreatment to introduce active groups on the fabric surface, providing sufficient reaction sites for the cross-linking of the subsequent coating. S2: Mix photochromic microcapsules, thermochromic microcapsules, quaternary phosphonium salt modified montmorillonite, nano zinc oxide, thermosensitive antibacterial enhancer, photocatalytic color-changing aid, and pH-responsive antibacterial sustained-release agent in proportion, add deionized water and stir at high speed for pre-dispersion treatment to ensure uniform dispersion of each functional component; S3: Pour the waterborne polyurethane emulsion into the reactor, add triethanolamine to adjust the pH of the system to a suitable range, and then slowly and uniformly add the pre-dispersed functional component slurry, stirring and mixing at low speed throughout the process; S4: Add aziridine crosslinking agent, crosslinking adhesion promoter, and silicone leveling agent to the uniformly mixed system, and continue stirring for 30 minutes to allow the crosslinking agent to react initially with the functional groups of waterborne polyurethane, while allowing the adhesion promoter to adapt to the active groups on the surface of the pretreated fabric in advance. S5: Fix the pretreated polyester fiber fabric onto the unwinding device of the doctor blade coating equipment, start the equipment to evenly coat the prepared functional coating paste onto the fabric surface, and control the coating thickness. S6: Send the coated fabric into a pre-drying oven and pre-dry it at 100℃ for 3 minutes to allow the moisture in the coating to evaporate quickly and promote the initial cross-linking of the cross-linking agent with the active groups of the fabric and the film-forming agent. S7: The pre-dried fabric is placed in a high-temperature curing oven and heated to 150°C for 2 minutes to allow the crosslinking system to react fully and build a three-dimensional crosslinking network of substrate, coating and functional components. S8: The cured fabric is placed in 100℃ hot water for washing to remove the uncrosslinked free components on the fabric surface. Then it is taken out and air-dried to complete the preparation of the wash-resistant color-changing antibacterial fabric.

3. The method for preparing a washable, color-changing, antibacterial fabric as described in claim 1, characterized in that: In step S1, the polyester fiber fabric is completely immersed in a sodium hydroxide solution with a concentration of 20 g / L and kept at 95°C for 45 minutes, with gentle stirring every 10 minutes to ensure that the polyester molecules on the fabric surface are fully hydrolyzed. After the treatment, the fabric is taken out and rinsed repeatedly with running water until neutral. Then it is immersed in a γ-aminopropyltriethoxysilane solution with a concentration of 5 g / L and left to soak at 30°C for 2 hours to allow the silane reagent to fully react with the hydroxyl groups on the fabric surface and introduce amino active groups. Finally, the fabric is taken out and placed in an 80°C hot air circulating oven to dry for 30 minutes.

4. The method for preparing a washable, color-changing, antibacterial fabric as described in claim 1, characterized in that: In step S2, photochromic microcapsules, thermochromic microcapsules, quaternary phosphonium salt modified montmorillonite, nano zinc oxide, thermosensitive antibacterial enhancer, photocatalytic color-changing aid, and pH-responsive antibacterial sustained-release agent are weighed in sequence according to the formula ratio. All components are added to a dispersion tank containing deionized water, with the amount of deionized water being 3 times the total mass of the functional components. The high-speed stirring device of the dispersion tank is started, the speed is adjusted to 1200 rpm, and stirring is continued for 45 minutes. During the stirring process, the temperature inside the dispersion tank is controlled not to exceed 35°C.

5. The method for preparing a washable, color-changing, antibacterial fabric as described in claim 1, characterized in that: In step S3, the formulated amount of aqueous polyurethane emulsion is poured into a reactor equipped with a heating jacket. The low-speed stirring device of the reactor is started, and the speed is adjusted to 300 rpm. At the same time, constant temperature water at 30°C is circulated through the jacket to maintain a stable temperature inside the reactor. Triethanolamine is slowly added dropwise to the reactor to adjust the pH value of the system to between 8 and 9, ensuring that the aqueous polyurethane is in a stable dispersion state. Then, the filtered functional component dispersion is added at a uniform rate of 50 ml per minute, and low-speed stirring is maintained throughout the process for 60 minutes.

6. The method for preparing a washable, color-changing, antibacterial fabric as described in claim 1, characterized in that: In step S4, the formulated amount of crosslinking adhesion promoter is first added to the reactor, and stirring is continued for 10 minutes to allow the active groups of the adhesion promoter to react initially with the terminal hydroxyl groups of the waterborne polyurethane, while simultaneously adapting the amino active groups on the surface of the pretreated fabric. Next, the formulated amount of aziridine crosslinking agent is added, the stirring speed is adjusted to 400 rpm, and stirring is continued for 15 minutes to allow the crosslinking agent to fully contact the carboxyl and hydroxyl groups of the waterborne polyurethane and undergo a preliminary crosslinking reaction. Finally, the formulated amount of organosilicon leveling agent is added, and stirring is continued for 5 minutes.

7. The method for preparing a washable, color-changing, antibacterial fabric as described in claim 1, characterized in that: In step S5, the pretreated polyester fiber fabric is fixed on the unwinding device of the doctor blade coating equipment, and the unwinding tension is adjusted to 15N to ensure that the fabric is flat and wrinkle-free; the doctor blade gap is adjusted to 150 micrometers, the fabric feeding speed is set to 5 meters per minute, the coating equipment is started, and the functional coating paste prepared in the reactor is evenly coated on the fabric surface, and the dry weight of the coating is controlled to be 30 grams per square meter.

8. The method for preparing a washable, color-changing, antibacterial fabric as described in claim 1, characterized in that: In step S6, the coated fabric is sent into a pre-drying oven, the oven temperature is set to 100°C, the hot air speed is 1.5 meters per second, and the fabric's running speed in the oven is consistent with the coating speed, maintaining a pre-drying time of 3 minutes. During the pre-drying process, the moisture in the coating slurry evaporates rapidly, and the aziridine crosslinking agent undergoes a preliminary crosslinking reaction with the amino active groups and functional groups of waterborne polyurethane on the fabric surface, temporarily fixing the functional coating on the fabric surface, avoiding coating sagging or functional component migration during subsequent high-temperature curing, while ensuring that the coating surface is smooth and free of bubbles.

9. The method for preparing a washable, color-changing, antibacterial fabric as described in claim 1, characterized in that: In step S7, the pre-dried fabric is sent into a high-temperature curing oven. The oven is set to a heating rate of 10°C per minute and gradually heated to 150°C. The curing time is maintained for 2 minutes. The oven uses a hot air circulation method with symmetrical blowing from top to bottom to ensure that the temperature of each part of the fabric is uniform.

10. The method for preparing a washable, color-changing, antibacterial fabric as described in claim 1, characterized in that: In step S8, the cured fabric is placed in a water washing tank containing 100°C hot water, the bath ratio is controlled at 1:20, and the fabric is gently stirred and washed for 10 minutes to remove the uncrosslinked free components and residual small molecules on the surface of the fabric. After washing, remove the fabric and rinse it with running cold water until it reaches room temperature. Then hang it in a well-ventilated environment with a temperature of 25°C and a relative humidity of 60% to air dry naturally for 24 hours.

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