Mildew-proof and antibacterial fabric and preparation process thereof

Abstract

The invention relates to a mildew-proof antibacterial fabric and a preparation process thereof, and belongs to the technical field of textile functional finishing, the mildew-proof antibacterial fabric comprises a cellulose base cloth and a modified finishing layer attached to the surface of the cellulose base cloth; the modified finishing layer is prepared from the following raw materials in parts by weight: 30 parts of a silane coupling agent containing an epoxy group, 50 parts of salicylaldehyde and 20 parts of zinc salt based on 100 parts by weight of hyperbranched polyethyleneimine; the modified finishing layer is formed in the mode that the raw materials react under the condition that 800-1200 parts of absolute ethyl alcohol serves as a reaction solvent to prepare finishing liquid, the finishing liquid is applied to the surface of the cellulose base cloth and cured, permanent fixation of the protective layer is achieved, and the technical problem that an antibacterial agent is prone to falling off is solved; by adjusting the molecular weight of the hyperbranched polyethyleneimine and the proportion of the zinc salt, the hyperbranched polyethyleneimine zinc salt can adapt to different application scenes.

Description

Technical Field

[0001] This invention relates to the field of functional finishing of textiles, specifically to an anti-mildew and antibacterial fabric and its preparation process. Background Technology

[0002] With the increasing awareness of health, the demand for textiles with biological protection functions is growing in the fields of clothing, home furnishing and outdoor industries; especially for cellulosic fiber fabrics, due to their porous structure and hydrophilic properties, they are very easy to breed bacteria and fungi in humid environments; current antibacterial finishing technology mainly relies on physical adsorption or electrostatic bonding to load antibacterial active ingredients onto the fiber surface. However, existing technologies still face significant limitations in practical applications. First, the washability of fabrics is generally poor. Since the binding force between antibacterial agents and fibers mainly relies on van der Waals forces or hydrogen bonds, the active ingredients are easily lost after repeated washing and mechanical friction, resulting in a sharp drop in protective effect. Second, the protective spectrum is relatively limited. Although many commonly used finishing agents have a certain inhibitory effect on bacteria such as Staphylococcus aureus, their defense against fungi such as mold is significantly insufficient, and the fabric will still develop mold spots and odors during long-term storage or outdoor use. In addition, some high-concentration finishing agents often significantly change the feel of the fabric, making it stiff and reducing wearing comfort, and there is a risk of skin irritation from the uncontrolled release of active ions. Therefore, developing a finishing solution that can balance high-efficiency antibacterial and anti-mildew properties, excellent wash durability, and good wearability is a pressing problem to be solved in the field of textile chemistry.

[0003] The information disclosed in the background section is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0004] The purpose of this invention is to provide an anti-mildew and antibacterial fabric and its preparation process, so as to solve the problems mentioned in the background art. Specifically, the technical solution of this invention is as follows: An anti-mildew and antibacterial fabric includes a cellulose base fabric and a modified finishing layer attached to the surface of the cellulose base fabric; The modified finishing layer is prepared from the following raw materials in parts by weight: 100 parts by weight of hyperbranched polyethyleneimine, 30 parts of silane coupling agent containing epoxy groups, 50 parts of salicylaldehyde, and 20 parts of zinc salt; the modified finishing layer is formed by reacting the above raw materials with 800-1200 parts of anhydrous ethanol as the reaction solvent to obtain a finishing liquid, which is then applied to the surface of cellulose base fabric and cured.

[0005] Preferably, the hyperbranched polyethyleneimine has a molecular weight of 5000-20000; the epoxy group-containing silane coupling agent is selected from γ-(2,3-epoxypropoxy)propyltrimethoxysilane; and the zinc salt is selected from at least one of zinc acetate dihydrate and zinc chloride.

[0006] Preferably, the modified finishing layer is formed by impregnating and baking the cellulose base fabric with an anti-mildew and antibacterial finishing liquid prepared from the raw materials; The preparation process of the anti-mildew and antibacterial finishing solution includes the following steps: Step S1: Add hyperbranched polyethyleneimine to a reactor equipped with a reflux condenser, add anhydrous ethanol, turn on mechanical stirring, set the speed to 200-400 r / min, stir until completely dissolved, slowly add silane coupling agent containing epoxy groups dropwise while stirring, after the addition is complete, raise the temperature to 50-70℃, keep the reaction at this temperature for 3-6 h, and obtain a silanized intermediate solution; Step S2: Add salicylaldehyde to the silanization intermediate solution obtained in step S1, heat to 75-80℃, and reflux for 2-4 hours to obtain the Schiff base precursor solution. Step S3: Dissolve zinc salt in 100-200 parts of anhydrous ethanol and add it dropwise to the Schiff base precursor solution obtained in step S2. Adjust the system temperature to 60-70℃ and continue the reaction for 1-3 hours. After the reaction is completed, cool naturally to room temperature to obtain the anti-mildew and antibacterial finishing solution stock solution.

[0007] Preferably, in step S1, the dropping rate is controlled at 1-2 mL / min; in step S2, the disappearance of the aldehyde group or the absorbance at 400 nm is detected by thin-layer chromatography as the end of the reaction.

[0008] Preferably, in step S3, the molar ratio of zinc salt to salicylaldehyde is controlled at 1:1.8 to 1:2.2, and the mechanical stirring speed is maintained at 300 to 500 r / min during the reaction.

[0009] A process for preparing an anti-mildew and antibacterial fabric includes the following steps: Step A: Take the stock solution of anti-mildew and antibacterial finishing solution, dilute it with deionized water, turn on the ultrasonic disperser, set the frequency to 20-40kHz and the power to 300-600W, disperse for 10-20 minutes, and adjust the pH value to 6.0-6.5 to prepare a finishing working solution with a mass concentration of 10-50g / L. Step B: Immerse the cellulose base fabric in the finishing solution prepared in Step A, and perform a two-dip and two-nip treatment, controlling the nip rate to be 70-85%, so that the finishing solution can penetrate evenly into the fiber. Step C: The cellulose base fabric treated in step B is sent into an oven for gradient heating treatment. First, it is pre-dried at 80-100℃ for 2-5 minutes, and then the temperature is raised to 150-170℃ for baking treatment for 90-180 seconds. After baking, it is washed with water and dried to obtain the finished product.

[0010] Preferably, in step A, a dilute acetic acid solution or a buffer solution is used to adjust the pH value; in step B, the process speed of the two-dip and two-roll process is controlled at 20-40 m / min.

[0011] Preferably, during the baking process in step C, high temperature is used to induce a dehydration condensation reaction between the silanol groups in the finishing working solution and the hydroxyl groups on the surface of the cellulose fibers, forming covalent bonds.

[0012] Compared with the prior art, the present invention has the following improvements and advantages: 1. This invention achieves permanent adhesion of the protective layer, solving the technical problem of easy detachment of antibacterial agents; By adjusting the molecular weight of hyperbranched polyethyleneimine and the zinc salt ratio, it can be adapted to different application scenarios. 2. This solution effectively avoids common problems in traditional finishing processes, such as silicone spots, color stains, and fiber strength damage, through precise control of the finishing solution's pH value and baking gradient. It maintains an excellent monodisperse state, ensuring a balance between fabric colorfastness and antibacterial properties. Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0014] Example 1: This invention provides an anti-mildew and antibacterial fabric, comprising a cellulose base fabric and a modified finishing layer attached to the surface of the cellulose base fabric; the modified finishing layer is prepared from raw materials comprising the following parts by weight: 100 parts hyperbranched polyethyleneimine, 30 parts silane coupling agent containing epoxy groups, 50 parts salicylaldehyde, and 20 parts zinc salt; the solvent used is 1000 parts anhydrous ethanol, and another 1000 parts deionized water is used for dilution in subsequent step A; This embodiment, as the most preferred implementation of the present invention, specifically uses 100 parts of hyperbranched polyethyleneimine, 30 parts of silane coupling agent containing epoxy groups, 50 parts of salicylaldehyde, 20 parts of zinc salt, 1000 parts of anhydrous ethanol, and 1000 parts of anhydrous ethanol for preparation. This ratio is based on precise calculation of stoichiometry and aims to construct a high-density core-shell hybrid network. The hyperbranched polyethyleneimine, as an amino-rich spherical core, provides sufficient reaction sites for the subsequent grafting reaction, while an appropriate amount of ethanol, as a co-solvent, effectively reduces the surface tension of the system and promotes the Brownian motion and collision probability of the reactant molecules. The molecular weight of hyperbranched polyethyleneimine is 5000-20000; the silane coupling agent containing epoxy groups is γ-(2,3-epoxypropoxy)propyltrimethoxysilane; the zinc salt is at least one of zinc acetate dihydrate and zinc chloride. In this embodiment, hyperbranched polyethyleneimine with a molecular weight of 10,000 was specifically selected. This molecular weight polymer has a suitable hydrodynamic radius, which ensures that the nanocage has sufficient cavities to accommodate zinc ions, while also preventing it from being too large to penetrate the microporous structure of the cotton fiber. The silane coupling agent selected is γ-(2,3-epoxypropoxy)propyltrimethoxysilane, which utilizes its highly active epoxy groups to achieve ring-opening addition with the polymer amino group. The zinc salt specifically selected is zinc acetate dihydrate, which utilizes the relatively weak coordination ability of the acetate group to facilitate replacement by the salicylaldehyde Schiff base group in subsequent reactions, forming a more stable chelate. The modified finishing layer is formed by impregnating and baking a cellulose base fabric with an anti-mildew and antibacterial finishing liquid prepared from raw materials. The preparation process of the anti-mildew and antibacterial finishing liquid includes the following steps: Step S1: Hyperbranched polyethyleneimine is added to a reaction vessel equipped with a reflux condenser, anhydrous ethanol is added, mechanical stirring is turned on, the speed is set to 200-400 r / min, and stirring is carried out until completely dissolved. Under stirring, a silane coupling agent containing epoxy groups is slowly added dropwise. After the addition is completed, the temperature is raised to 50-70℃ and the reaction is kept at the temperature for 3-6 h to obtain a silanized intermediate solution. The core of step S1 lies in the in-situ construction of a polymer skeleton with anchoring claws. Specifically, the rotation speed is set to 300 r / min, the dropping rate is strictly controlled at 1.5 mL / min, and after dropping, the temperature is raised to 60℃ and maintained for 4 hours. Under these conditions, the epoxy groups mainly undergo nucleophilic ring-opening reactions with the primary amines at the ends of the hyperbranched polyethyleneimine to generate secondary amines and hydroxyl groups, thus avoiding excessive reaction with secondary amines that would lead to increased steric hindrance. This process introduces siloxane groups that can react with fibers while retaining the internal cavity structure for subsequent metal loading. To clarify the technical solution, infrared spectroscopy characterization revealed the disappearance of the epoxy group characteristic peak near 910 cm⁻¹ and the appearance of a broad hydroxyl absorption peak near 3400 cm⁻¹, proving that the epoxy groups have been completely ring-opened. The ring-opening addition reaction equation for this step is as follows: ; in, Represents the terminal primary amine of hyperbranched polyethyleneimine; Step S2: Salicylic aldehyde is added to the silanized intermediate solution obtained in Step S1, and the temperature is raised to 75-80℃ for reflux reaction for 2-4 hours to obtain a Schiff base precursor solution. Step S2 aims to introduce photothermal stabilizing groups through a condensation reaction. Specifically, the temperature is raised to 78℃ and refluxed for 3 hours to promote the dehydration condensation of the aldehyde group with the remaining primary amine on the polymer, forming a C=N double bond. The formation of this conjugated structure not only endows the molecule with excellent ultraviolet absorption capacity but also provides a rigid planar structural basis for the subsequent coordination of zinc ions. The condensation reaction equation in this step is: ; in, Representing salicylaldehyde, the resulting Schiff base structure provides the necessary site for metal coordination; Step S3: Dissolve zinc salt in 100-200 parts of anhydrous ethanol and add it dropwise to the Schiff base precursor solution obtained in step S2. Adjust the system temperature to 60-70℃ and continue the reaction for 1-3 hours. After the reaction is completed, cool naturally to room temperature to obtain the anti-mildew and antibacterial finishing solution stock solution. Step S3 is a crucial stage in supramolecular assembly; specifically, 20 parts of zinc acetate dihydrate are dissolved and added dropwise, and the temperature is adjusted to 65℃ for 2 hours. During this process, zinc ions are captured and enter the internal cavity of the hyperbranched polymer, forming a stable four-coordinate chelate structure with the nitrogen atom and phenolic hydroxyl oxygen atom in the Schiff base group. This cage-like coating structure effectively shields the active metal center from external interference and reduces the uncontrolled release rate of zinc ions. The coordination reaction equation can be expressed as: ; In step S1, the dropping rate is controlled at 1-2 mL / min based on the volume of the reaction system in this embodiment; in step S2, the disappearance of the aldehyde group or the stabilization of the absorbance at 400 nm is detected by thin-layer chromatography as the end of the reaction. The change in solution color from colorless to bright yellow is a macroscopic characterization of the establishment of the conjugated system, indicating that a large number of Schiff base structures have been generated and the electron cloud density has been delocalized; the precise control of the dropping rate is to prevent silane self-polymerization caused by excessive local concentration; in step S3, the molar ratio of zinc salt to salicylaldehyde is controlled at 1:1.8 to 1:2.2, and the mechanical stirring speed is maintained at 300 to 500 r / min during the reaction. In this embodiment, the molar ratio of zinc salt to salicylaldehyde is precisely controlled at 1:2, and the rotation speed is maintained at 400 r / min. This stoichiometric ratio ensures that each zinc ion can be saturated with two salicylaldehyde ligands to form an electrically neutral or weakly cationic complex, thus avoiding the problem of metal ions easily falling off during the washing process due to unsaturated coordination. A process for preparing an anti-mildew and antibacterial fabric includes the following steps: Step A: Take the original anti-mildew and antibacterial finishing liquid, add deionized water for dilution, turn on the ultrasonic disperser, set the frequency to 20-40kHz, disperse for 10-20 minutes, and adjust the pH value to 4.5-6.5 to prepare a finishing working solution with a mass concentration of 10-50g / L. The ultrasonic dispersion treatment in step A, at 30 kHz for 15 min, utilized the cavitation effect to break up any possible soft aggregates, resulting in a monodisperse distribution of the nanocage particles. Adjusting the pH to 5.5 using a 1.0 mol / L acetic acid solution was based on the aforementioned mechanistic model. This weakly acidic environment both inhibited the condensation of silanols and promoted the protonation of hydroxyl groups on the surface of cellulose fibers, which was beneficial for subsequent adsorption. Step B: Immerse the cellulose base fabric in the finishing solution prepared in Step A, and perform a two-dip and two-nip treatment, controlling the nip rate to be 70-85%, so that the finishing solution can penetrate evenly into the fiber. Step B employs a two-dip and two-roll process with a machine speed of 30m / min and a roll-off rate of 80%. By utilizing the hydraulic difference generated by mechanical extrusion, the finishing liquid is forced to break through the boundary layer on the fiber surface and penetrate deep into the space between the fiber's cortex and core, achieving all-round protection from the inside out. Step C: The cellulose base fabric treated in step B is sent into an oven for gradient heating treatment. First, it is pre-dried at 80-100℃ for 2-5 minutes, and then the temperature is raised to 150-170℃ for baking treatment for 90-180 seconds. After baking, it is washed with water and dried to obtain the finished product. The gradient heating strategy in step C is crucial; pre-baking at 90℃ for 3 minutes aims to remove most of the free water, allowing the finishing agent molecules to complete pre-orientation on the fiber surface; the subsequent baking at 160℃ for 120 seconds provides the activation energy required to overcome the reaction energy barrier, prompting the silanol groups in the finishing agent to undergo a dehydration condensation reaction with the C6 primary hydroxyl group on the cellulose glucose ring, forming a Si-OC covalent bond with a bond energy as high as 452 kJ / mol, thereby achieving permanent fixation of the antibacterial and antifungal layer. The condensation reaction equation is as follows: ; In step A, acetic acid solution is used to adjust the pH value; the mass percentage concentration of acetic acid solution is 5% to 10%; in step B, the process speed of the two dips and two nips is controlled at 20 to 40 m / min; the pH value is adjusted by using 1.0 mol / L acetic acid solution to introduce the common ion effect and stabilize the acetate ligands in the system; the appropriate speed ensures the residence time of the fabric in the nips and ensures the establishment of wetting balance; During the baking process in step C, high temperature is used to induce the silanol groups in the finishing working solution to undergo a dehydration condensation reaction with the hydroxyl groups on the surface of cellulose fibers, forming covalent bonds. This covalent bond mechanism is the core of this invention that distinguishes it from traditional physical adhesion finishing, and solves the technical pain point of poor wash resistance of antibacterial agents.

[0015] Example 2: An anti-mildew and antibacterial fabric, wherein the modified finishing layer raw materials include: 80 parts hyperbranched polyethyleneimine, 20 parts silane coupling agent containing epoxy groups, 40 parts salicylaldehyde, 15 parts zinc salt, 800 parts anhydrous ethanol and 10,000 parts deionized water; the molecular weight of the hyperbranched polyethyleneimine is 5,000; the zinc salt is zinc chloride. This embodiment aims to develop a lightweight antibacterial fabric suitable for close-fitting clothing. To this end, hyperbranched polyethyleneimine with a low molecular weight of 5000 was selected. Its small radius of gyration allows it to penetrate more easily into the amorphous region of the fiber, reducing the stiffness caused by surface film formation. At the same time, zinc chloride was selected as the zinc source, and the small ionic radius of chloride ions improved the penetration rate of the finishing solution.

[0016] The preparation process includes step A, adjusting the pH value to 4.5 to prepare a finishing working solution with a mass concentration of 10 g / L; step B, the pick-up rate is 70%; step C, pre-drying at 80℃ for 5 min, followed by baking at 150℃ for 180 s; in terms of process adjustment, a 1.0 mol / L acetic acid solution is used to adjust the pH value, while the concentration of the finishing solution is reduced to 10 g / L and the baking time is extended to 180 s; this low concentration and long baking strategy helps to form an extremely thin but dense monolayer protective film, maximizing the preservation of the original soft hand feel and breathability of the fabric; although the total amount of active substances is reduced, due to the small molecular weight and uniform distribution, it still maintains excellent antibacterial efficiency, which is particularly suitable for the summer underwear industry.

[0017] Example 3: A mildew-proof and antibacterial fabric, wherein the modified finishing layer raw materials include: 120 parts hyperbranched polyethyleneimine, 40 parts silane coupling agent containing epoxy groups, 60 parts salicylaldehyde, 25 parts zinc salt, 1200 parts anhydrous ethanol and 50000 parts deionized water, wherein the molecular weight of the hyperbranched polyethyleneimine is 20000. This embodiment focuses on protective performance under extreme environments; high molecular weight, 20,000 hyperbranched polyethyleneimine and a high proportion of silane coupling agent, 40 parts, were selected; this macromolecular backbone provides more terminal functional groups, constructing a large-volume nanocage structure that can load a higher density of antibacterial active centers; the high content of silane coupling agent enhances the crosslinking density of the film layer, forming a hydrophobic barrier similar to armor. The preparation process includes step A, preparing a finishing working solution with a mass concentration of 50 g / L; step C, pre-drying at 100℃ for 2 min, followed by baking at 170℃ for 90 s; the process employs a high concentration of 50 g / L and high temperature, 170℃ impact baking; the high temperature causes the high concentration of silane coupling agent to not only react with the fiber surface, but also undergo a high degree of self-condensation between the finishing agent molecules, forming a thick hybrid network protective layer on the fiber surface; this layer structure gives the fabric extremely strong abrasion resistance and washability, and can effectively resist the erosion of strong molds such as Chaetomium globosum even in damp and muddy outdoor environments. Although the hand feel is slightly stiff, it fully meets the needs of industrial textiles such as tents and canvas.

[0018] Example 4: A mildew-proof and antibacterial fabric, wherein the zinc salt in the raw material is a mixture of zinc acetate dihydrate and zinc chloride in a 1:1 mass ratio; This embodiment explores the synergistic effect of mixed zinc sources; by using zinc acetate dihydrate and zinc chloride in combination, the buffering effect of acetate ions is used to stabilize the reaction pH value, while the strong permeability of chloride ions is used to promote the diffusion of finishing agents into the fiber interior; this mixing strategy makes the formed nanocage structure exhibit a richer potential distribution gradient at the microscopic level, which helps to more effectively disrupt the cell membrane potential of bacteria and interfere with their metabolic processes. In the preparation process, the reaction temperature in step S1 is 60℃; in step S3, the molar ratio of zinc salt to salicylaldehyde is 1:2.1. In terms of preparation details, the molar ratio of zinc salt to salicylaldehyde is finely adjusted to 1:2.1. The slightly excess salicylaldehyde ensures complete coordination of zinc ions and eliminates the risk of skin irritation that may be caused by free zinc ions. This method achieves a good balance between cost control, the low cost of zinc chloride, and performance, and is suitable for cost-sensitive fields such as hotel bedding that require frequent industrial washing.

[0019] Example 5: In a mildew-proof and antibacterial fabric, in step S3, the molar ratio of zinc salt to salicylaldehyde is controlled at 1:1.9, and the reaction is carried out at 68°C for 2.5 hours; in step A, the pH is adjusted to 6.0. This embodiment focuses on the impact of fine control of process parameters on the final product appearance quality. Using a 1.0 mol / L acetic acid solution to precisely adjust the pH value to 6.0, which is within the optimal window period for silanol group stability, effectively prevents premature gelation of the finishing solution in the padding tank, thereby eliminating the generation of silicone spots or color stains on the fabric surface; at the same time, the 1:1.9 molar ratio deliberately retains a very small amount of uncoordinated Schiff base groups, which can further participate in cross-linking during high-temperature baking, improving the density of the film layer; The preparation process includes pre-drying at 95℃ for 3 minutes and baking at 165℃ for 140 seconds in step C. The baking process uses intermediate parameters of 165℃ and 140 seconds, which ensures efficient covalent bond formation and avoids yellowing or strong damage to cotton fibers caused by prolonged high-temperature treatment. The results show that the fabric prepared by this process has excellent color fastness and minimal degradation of antibacterial and antifungal properties after multiple washes, verifying the effectiveness of process optimization.

[0020] Comparative Example 1: This comparative example provides a method for preparing an anti-mildew and antibacterial fabric. The raw material composition is basically the same as that in Example 1, except that: in the preparation of the finishing solution in step A, hydrochloric acid is used to adjust the pH value to 3.0, which exceeds the preferred pH range of 4.5 to 6.5 described in this application. Under this strongly acidic environment, according to the pre-established mechanism model, the Schiff base structure undergoes significant reversible proton dissociation, resulting in a decrease in the coating stability of zinc ions. At the same time, the acidic hydrolysis rate of the silane coupling agent is too fast, which easily forms unstable oligomers in the system. This comparative example aims to verify the influence of pH parameter boundaries, especially the strongly acidic boundary, on the structural integrity of the finishing solution and the final anti-mildew performance.

[0021] Comparative Example 2: This comparative example provides a method for preparing an anti-mildew and antibacterial fabric. The raw material composition is basically the same as that in Example 1, except that in step S3, the molar ratio of zinc salt to salicylaldehyde is controlled to be 1:1, which exceeds the range of 1:1.8 to 1:2.2 recorded. Under this ratio, zinc ions cannot achieve complete six-coordinate or four-coordinate saturation, resulting in coordination vacancies in the structure of the formed complex, and some zinc ions exist in the form of weakly binding ionic bonds. This comparative example aims to verify the effect of the boundary value of the coordination stoichiometry on the structural stability and wash resistance of the antibacterial agent.

[0022] Comparative Example 3: This comparative example uses a commercially available quaternary ammonium salt antibacterial finishing agent, the main component of which is 3-trimethoxysilylpropyldimethyloctadecylammonium chloride. The same cotton fabric was treated according to its recommended process, with a finishing solution concentration of 30 g / L. The same padding and baking processes were used, and the fabric was baked at 160°C. This comparative example represents the mainstream antibacterial finishing scheme in the prior art and is used to compare the advantages of the novel hybrid nanocage structure of this invention in terms of broad spectrum, especially in terms of mildew resistance and durability.

[0023] Comparative Example 4: This comparative example uses the same raw material formulation and pretreatment process as Example 1; however, in the post-treatment stage of step C, the baking temperature is set to 140°C, which is lower than the range of 150-170°C described above, and the baking time is maintained at 180s. This temperature is lower than the activation energy threshold required for the effective dehydration condensation reaction between silanol and cellulose hydroxyl groups, making it difficult to form high-density covalent bonds. The finished layer mainly relies on physical adsorption and partial hydrogen bonding to adhere. This comparative example aims to verify the decisive role of the baking temperature parameter boundary on the chemical anchoring effect and washability.

[0024] Verification test In order to comprehensively evaluate the practical application value of the anti-mildew and antibacterial fabric of the present invention, multi-dimensional performance tests were conducted on the fabrics prepared in Examples 1-5 and Comparative Examples 1-4.

[0025] Test Standards 1. Antibacterial properties: The inhibition rate against Staphylococcus aureus (S. aureus, representing Gram-positive bacteria) and Escherichia coli (E. coli, representing Gram-negative bacteria) was tested using the shaking method according to GB / T20944.3-2008 "Evaluation of antibacterial properties of textiles". 2. Anti-mildew performance: The evaluation of anti-mildew performance of textiles was conducted in accordance with GB / T24346-2009 "Evaluation of anti-mildew performance of textiles". The test was conducted on the growth of mixed molds, including Aspergillus niger, Chaetomium globulus, Penicillium, etc. The rating standards were as follows: Grade 0 - no growth, no hyphae under microscope; Grade 1 - trace growth, coverage area <10%; Grade 2 - slight growth; Grade 3 - moderate growth; Grade 4 - severe growth. 3. Washability test: According to the AATCC 61-2A standard procedure, an accelerated washing test was conducted at 40℃, equivalent to 50 household machine washes. After washing, the above antibacterial and anti-mildew indicators were retested. 4. Characterization of surface chemical bonding and simulation of peel strength: The bonding strength between the finishing layer and the fiber was evaluated by using the tape peeling method combined with scanning electron microscopy, and the weight loss rate (%) before and after washing was calculated to indirectly characterize the degree of chemical bonding.

[0026] Specific testing process All tests were conducted in a constant temperature and humidity laboratory at 20±2℃ and 65±4%RH; each sample was tested in triplicate, and the average value was taken to eliminate random errors; in the antibacterial test, the concentration of the inoculum was controlled at... CFU / mL, with a shaking contact time of 18 hours; in the anti-mildew test, the sample was placed in an incubator at a temperature of 28℃ and a humidity of over 90% for 28 days.

[0027] Data table Group Antibacterial rate (%) Staphylococcus aureus Antibacterial rate (%) Escherichia coli Anti-mold rating (mixed mold) Antibacterial rate after 50 washes (S. aureus, %) Anti-mildew rating after 50 washes Weight loss rate (%, after 50 washes) Example 1 >99.9 >99.9 Level 0 96.5 Level 1 1.2 Example 2 99.5 99.2 Level 0 92.1 Level 1 1.8 Example 3 >99.9 >99.9 Level 0 98.2 Level 0 0.9 Example 4 99.8 99.6 Level 0 94.5 Level 1 1.5 Example 5 >99.9 >99.9 Level 0 97.1 Level 0-1 1.1 Comparative Example 1 99.1 98.5 Level 0 35.4 Level 4 15.6 Comparative Example 2 98.2 99.1 Level 3 90.5 Level 3 2.1 Comparative Example 3 99.5 99.3 Level 3 85.2 Level 3 4.5 Comparative Example 4 99.3 98.8 Level 0 42.1 Level 4 12.8 The fabric based on hyperbranched hybrid nanocages prepared by this invention exhibits significant advantages in antibacterial, antifungal, and washability properties. The decisive role of covalent bonding mechanism: Comparing Example 1 with Comparative Examples 1 and 4, it can be seen that due to the strong acid environment causing the silane coupling agent structure to fail or the lack of high-temperature baking, the sample of Comparative Example 4, although initially showing acceptable antibacterial effect, experienced a sharp drop in antibacterial rate to below 45% after 50 washes, with its anti-mildew level deteriorating to level 4 and a weight loss rate exceeding 12%. This strongly confirms that the present invention utilizes high-temperature baking to induce a dehydration condensation reaction between silanol groups and cellulose hydroxyl groups, forming a strong Si-OC covalent bond, which is the core key to achieving durability; only chemical bonding can resist mechanical friction and hydrolytic swelling during the washing process. Synergistic effect of organic-inorganic hybridization: Comparing Example 1 with Comparative Examples 2 and 3, it can be seen that relying solely on polymer cations, Comparative Example 2 or traditional quaternary ammonium salts, while showing good inhibitory effects on bacteria, have significantly insufficient inhibitory ability against fungi and molds, with an anti-mold level of only 3; while in Example 1, after introducing the salicylaldehyde-zinc complex, the anti-mold level reached 0; this indicates that the organic-inorganic hybridization constructed in this invention... The nanocage structure achieves functional complementarity: the hyperbranched polymer provides high-density positive charge adsorption of bacteria, while the zinc-Schiff base complex serves as a broad-spectrum bactericidal center, especially effective in destroying fungal cell walls. The two work together to achieve true broad-spectrum protection. Adjustability of structure and performance: Data from Examples 2 to 5 show that the performance focus of the fabric can be flexibly adjusted by modifying the molecular weight, zinc source, and process parameters. For example, Example 3 achieved optimal wash resistance, a post-wash antibacterial rate of 98.2%, and the lowest weight loss rate of 0.9% through high molecular weight and high concentration finishing, verifying the adaptability of the high cross-linking density network to extreme environments. In summary, the technical solution of this invention has achieved a substantial breakthrough in solving the problems of poor wash resistance and narrow anti-mildew spectrum of traditional antibacterial finishing agents.

[0028] It should be noted that 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 preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A mildew-proof and antibacterial fabric, characterized in that: It includes a cellulose base fabric and a modified finishing layer attached to the surface of the cellulose base fabric; The modified finishing layer is prepared from the following raw materials in parts by weight: 100 parts by weight of hyperbranched polyethyleneimine, 30 parts of silane coupling agent containing epoxy groups, 50 parts of salicylaldehyde, and 20 parts of zinc salt; the modified finishing layer is formed by reacting the above raw materials with 800-1200 parts of anhydrous ethanol as the reaction solvent to obtain a finishing liquid, which is then applied to the surface of cellulose base fabric and cured.

2. The anti-mildew and antibacterial fabric according to claim 1, characterized in that, The hyperbranched polyethyleneimine has a molecular weight of 5,000 to 20,000; the epoxy group-containing silane coupling agent is selected from γ-(2,3-epoxypropoxy)propyltrimethoxysilane; the zinc salt is selected from at least one of zinc acetate dihydrate and zinc chloride.

3. The anti-mildew and antibacterial fabric according to claim 1, characterized in that, The modified finishing layer is formed by impregnating and baking a cellulose base fabric with an anti-mildew and antibacterial finishing liquid prepared from the raw materials. The preparation process of the anti-mildew and antibacterial finishing solution includes the following steps: Step S1: Add hyperbranched polyethyleneimine to a reactor equipped with a reflux condenser, add anhydrous ethanol, turn on mechanical stirring, set the speed to 200-400 r / min, stir until completely dissolved, slowly add silane coupling agent containing epoxy groups dropwise while stirring, after the addition is complete, raise the temperature to 50-70℃, keep the reaction at this temperature for 3-6 h, and obtain a silanized intermediate solution; Step S2: Add salicylaldehyde to the silanization intermediate solution obtained in step S1, heat to 75-80℃, and reflux for 2-4 hours to obtain the Schiff base precursor solution. Step S3: Dissolve zinc salt in 100-200 parts of anhydrous ethanol and add it dropwise to the Schiff base precursor solution obtained in step S2. Adjust the system temperature to 60-70℃ and continue the reaction for 1-3 hours. After the reaction is completed, cool naturally to room temperature to obtain the anti-mildew and antibacterial finishing solution stock solution.

4. The anti-mildew and antibacterial fabric according to claim 3, characterized in that, In step S1, the dropping rate is controlled at 1-2 mL / min; in step S2, the disappearance of the aldehyde group or the absorbance at 400 nm is detected by thin-layer chromatography as the end of the reaction.

5. The anti-mildew and antibacterial fabric according to claim 3, characterized in that, In step S3, the molar ratio of zinc salt to salicylaldehyde is controlled at 1:1.8 to 1:2.2, and the mechanical stirring speed is maintained at 300 to 500 r / min during the reaction.

6. A process for preparing an anti-mildew and antibacterial fabric according to any one of claims 1 to 5, characterized in that, Includes the following steps: Step A: Take the stock solution of anti-mildew and antibacterial finishing solution, dilute it with deionized water, turn on the ultrasonic disperser, set the frequency to 20-40kHz and the power to 300-600W, disperse for 10-20 minutes, and adjust the pH value to 6.0-6.5 to prepare a finishing working solution with a mass concentration of 10-50g / L. Step B: Immerse the cellulose base fabric in the finishing solution prepared in Step A, and perform a two-dip and two-nip treatment, controlling the nip rate to be 70-85%, so that the finishing solution can penetrate evenly into the fiber. Step C: The cellulose base fabric treated in step B is sent into an oven for gradient heating treatment. First, it is pre-dried at 80-100℃ for 2-5 minutes, and then the temperature is raised to 150-170℃ for baking treatment for 90-180 seconds. After baking, it is washed with water and dried to obtain the finished product.

7. The preparation process of the anti-mildew and antibacterial fabric according to claim 6, characterized in that, In step A, a dilute acetic acid solution or buffer solution is used to adjust the pH value; in step B, the process speed of the two dips and two rolls is controlled at 20-40 m / min.

8. The preparation process of an anti-mildew and antibacterial fabric according to claim 6, characterized in that, During the baking process in step C, high temperature is used to induce a dehydration condensation reaction between the silanol groups in the finishing working solution and the hydroxyl groups on the surface of the cellulose fibers, forming covalent bonds.