Plant fiber breathable bacteriostatic sanitary towel and preparation method thereof

Abstract

The invention belongs to the technical field of sanitary napkins, and relates to a plant fiber breathable bacteriostatic sanitary napkin and a preparation method thereof.The plant fiber breathable bacteriostatic sanitary napkin comprises a liquid permeable surface layer, a flow guide bacteriostatic layer, an absorption core, a breathable bottom layer and a release film which are sequentially stacked and bonded; the diversion antibacterial layer is obtained by blending and hot-pressing modified plant fibers and modified polypropylene fibers; the modified plant fibers are obtained by soaking plant fibers in a bacteriostatic solution, and the bacteriostatic solution comprises tea polyphenol and salicylic acid which are co-included by beta-cyclodextrin, a chamomile extract coated by lecithin and chitosan quaternary ammonium salt; the modified polypropylene fibers are obtained by sequentially modifying polypropylene fibers by a silane coupling agent and grafting and modifying the polypropylene fibers by chitosan. The technical problems that a traditional sanitary towel product is not lasting in antibacterial effect, liquid permeation is slow, and bacteria are prone to breeding in a humid and hot environment are effectively solved, and the use safety and comfort of the sanitary towel are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of sanitary napkins and relates to a plant fiber breathable and antibacterial sanitary napkin and a preparation method thereof. Background Art

[0002] With the improvement of living standards and the enhancement of health awareness, the safety and functionality of feminine hygiene products are increasingly valued. Traditional sanitary napkins generally use synthetic polymer materials as the absorption layer and the diversion and antibacterial layer. Although they have good liquid retention capacity, they have problems such as poor air permeability and easy breeding of bacteria. Long-term use can easily lead to the formation of a local hot and humid environment, increasing the risk of skin irritation and infection. For this reason, antibacterial sanitary napkins with added inorganic antibacterial agents (such as silver ions) or natural extracts (such as chitosan) have appeared on the market, but their antibacterial ingredients are easily lost during processing or use, and some chemical antibacterial agents have biocompatibility risks. Although the application of plant fibers has improved in terms of air permeability and environmental protection in recent years, it is difficult for a single fiber material to meet the dual requirements of diversion efficiency and long-term antibacterial. The solutions in the prior art that load antibacterial ingredients by impregnation or coating often cause a sharp drop in antibacterial performance after washing and care due to insufficient binding force between the fiber and the active substance, and are prone to thermal decomposition and inactivation during high temperature and high pressure processing. Furthermore, the fiber layer structure formed by the traditional hot air consolidation process lacks fluffiness, which affects the liquid penetration rate and back-infiltration control effect, restricting the comfort and safety of the product. Therefore, developing a sanitary napkin structure that combines long-lasting antibacterial properties, efficient fluid diversion, breathable comfort, and environmental friendliness remains a technical bottleneck that needs to be overcome in this field. Summary of the Invention

[0003] In response to the shortcomings of the existing technology, the purpose of the present invention is to provide a plant fiber breathable antibacterial sanitary napkin and a preparation method thereof, which effectively solves the technical problems of traditional sanitary napkin products such as short-lasting antibacterial effect, slow liquid penetration, and easy breeding of bacteria in humid and hot environments, thereby improving the safety and comfort of sanitary napkins.

[0004] To achieve this object, the present invention adopts the following technical solutions:

[0005] In a first aspect, the present invention provides a plant fiber breathable and antibacterial sanitary napkin, the plant fiber breathable and antibacterial sanitary napkin comprising a liquid permeable surface layer, a diversion and antibacterial layer, an absorbent core, a breathable bottom layer, and a release film that are sequentially laminated and bonded;

[0006] The diversion and antibacterial layer is obtained by blending modified plant fibers and modified polypropylene fibers and hot pressing them;

[0007] The modified plant fiber is obtained by immersing the plant fiber in an antibacterial solution, wherein the antibacterial solution comprises tea polyphenols and salicylic acid co-enclosed by β-cyclodextrin, chamomile extract coated by lecithin, and chitosan quaternary ammonium salt;

[0008] The modified polypropylene fiber is obtained by sequentially modifying polypropylene fiber with a silane coupling agent and then grafting with chitosan.

[0009] The present invention maximizes the protection and release of multiple natural antibacterial active substances through β-cyclodextrin inclusion and liposome coating; significantly improves the hydrophilic flow conduction ability of polypropylene fiber and imparts it with antibacterial properties through chitosan grafting modification; finally, the modified plant fiber and modified polypropylene fiber are blended and hot-pressed to obtain a highly efficient and long-lasting antibacterial layer that can quickly conduct liquid and maintain high breathability. This effectively solves the technical problems of traditional sanitary napkin products such as short-lasting antibacterial effect, slow liquid penetration, and easy breeding of bacteria in hot and humid environments, thereby improving the safety and comfort of sanitary napkins.

[0010] The tea polyphenols and salicylic acid in the antibacterial liquid were co-encapsulated with β-cyclodextrin. β-cyclodextrin encapsulated the tea polyphenols and salicylic acid in its molecular cavity. On the one hand, this significantly improved the stability of salicylic acid (volatile) and tea polyphenols (easy to oxidize) during subsequent high-temperature processing (such as hot pressing) and long-term storage. On the other hand, the co-encapsulation achieved a slow release of the active ingredients. When the liquid came into contact with the diversion antibacterial layer, the inclusion complex gradually dissociated, and the tea polyphenols and salicylic acid worked synergistically. Tea polyphenols were mainly used to destroy bacterial cell membranes, while salicylic acid could more easily enter the interior of the bacteria and interfere with their metabolism. The combination of the two greatly enhanced the antibacterial effect and made the effect more lasting. Chamomile extract was coated with lecithin to form liposomes. Lecithin constructed a tiny vesicle structure, encapsulating the chamomile extract. The liposome coating greatly improved the survival rate of heat-sensitive essential oil components during processing. At the same time, the liposome structure also achieved a sustained-release effect, gradually releasing the soothing and calming ingredients of chamomile during use, playing a role in gently caring for the skin. As the third antibacterial ingredient, chitosan quaternary ammonium salt has positive charge characteristics that can effectively adsorb and destroy the negatively charged bacterial cell walls, forming a physical barrier.

[0011] Polypropylene fibers inherently possess excellent strength and chemical stability, but are naturally hydrophobic, hindering rapid liquid diversion. The present invention first activates the fibers with a silane coupling agent to create reactive groups on the surface. Chitosan grafting is then performed. This significantly improves the fibers' hydrophilicity, allowing liquids to spread and transfer rapidly across their surface. Furthermore, the chitosan itself imparts additional antibacterial properties. The modified polypropylene fibers provided by the present invention combine both hydrophilic diversion and auxiliary antibacterial functions.

[0012] Modified plant fibers are naturally hydrophilic, fluffy, and porous, making them ideal carriers for antibacterial liquids. After being impregnated with the liquid, their abundant pores and surfaces effectively load inclusion complexes, liposomes, and chitosan quaternary ammonium salts. When blended with modified polypropylene fibers, the two fibers complement each other. The modified polypropylene fibers provide structural strength and hydrophilic flow channels, ensuring rapid liquid penetration into the absorbent core; the modified plant fibers primarily provide powerful antibacterial properties, excellent moisture absorption and breathability, and a fluffy structure. Through wet-laid web formation and hot pressing, a highly porous, three-dimensional, interwoven structure with a diversion and antibacterial layer is created. This layer rapidly absorbs and channels liquid, preventing discomfort caused by residual liquid on the surface, while also allowing air to circulate freely, effectively dissipating moisture and maintaining a dry, comfortable environment at the site of application, thus effectively inhibiting bacterial growth in hot and humid environments.

[0013] In a second aspect, the present invention provides a method for preparing the plant fiber breathable and antibacterial sanitary napkin according to the first aspect, the preparation method comprising:

[0014] (I) tea polyphenols and salicylic acid are included in an inclusion complex using β-cyclodextrin, chamomile extract is coated with lecithin to obtain liposomes, and the inclusion complex, liposomes, chitosan quaternary ammonium salt and deionized water are mixed to obtain an antibacterial solution;

[0015] (II) modifying polypropylene fibers with a silane coupling agent, immersing the modified polypropylene fibers in a chitosan solution, and adding a crosslinking agent for crosslinking to obtain modified polypropylene fibers;

[0016] (III) immersing the plant fiber in the antibacterial solution obtained in step (I), taking out and drying to obtain a modified plant fiber, and blending the modified plant fiber with a modified polypropylene fiber and hot pressing to obtain a diversion and antibacterial layer;

[0017] (IV) stacking and bonding the liquid-permeable surface layer, the diversion and antibacterial layer, the absorbent core and the breathable bottom layer in sequence, and pasting a release film on the surface of the breathable bottom layer to obtain the plant fiber breathable and antibacterial sanitary napkin.

[0018] In the antibacterial liquid, the broad-spectrum antibacterial property of tea polyphenols and the anti-inflammatory and keratin softening functions of salicylic acid have the problem of poor compatibility stability. Salicylic acid is volatile and sensitive to heat, while tea polyphenols are easily oxidized and inactivated during processing. The present invention forms an inclusion compound with β-cyclodextrin after mixing the two, so that the hydrophobic molecules are embedded in the cavity structure of cyclodextrin. Through molecular-level encapsulation, not only the thermal stability of the composite active substance is greatly improved, but also the sustained-release effect is achieved through the hydrophilicity of the outer wall of cyclodextrin. When the liquid contacts the diversion antibacterial layer, the inclusion compound gradually dissociates and releases the antibacterial components, avoiding the sudden drop in antibacterial effect caused by one-time dissolution. In terms of antibacterial effect, tea polyphenols and salicylic acid produce synergistic synergy. After tea polyphenols destroy the bacterial cell membrane, salicylic acid is more easily penetrated into the inside of the bacteria to interfere with metabolism, which greatly improves the antibacterial rate.

[0019] For heat-sensitive essential oil components such as chamomile extract, the present invention drips the chamomile extract solution into the lecithin solution, forms nano-scale liposomes through high-speed shearing, and wraps the chamomile extract in the phospholipid bilayer. After removing the ethanol by rotary evaporation, the liposome particle size is controlled to be in the range of 100 to 200 nm through ultrafiltration process, and finally freeze-dried under the protection of trehalose. The liposomes prepared by the preparation method provided by the present invention enable the calming and soothing components of the chamomile extract to be slowly released during the storage and use of the sanitary napkin. The addition of chitosan quaternary ammonium salt further enhances the antibacterial effect. Its cationic properties can adsorb negatively charged bacteria, destroy the integrity of the cell wall, and produce a charge synergistic effect with components such as tea polyphenols.

[0020] In terms of polypropylene fiber modification, the hydrolysis product of the silane coupling agent forms a -Si-OC- covalent bond with the surface of the polypropylene fiber, creating active sites for subsequent grafting. Under a negative pressure environment, the silane-modified fiber is immersed in a chitosan solution, allowing the chitosan molecular chain to fully penetrate into the fiber micropores, and then cross-linked with genipin to form a three-dimensional network structure. The surface of the modified polypropylene fiber obtained is rich in amino cations, which not only have antibacterial properties themselves, but also greatly enhance the hydrophilicity of the fiber surface, allowing the liquid to diffuse rapidly laterally. After the plant fiber is impregnated with the antibacterial liquid, its natural porous structure is loaded with inclusion complexes, liposomes and chitosan quaternary ammonium salts, forming a composite fiber loaded with active ingredients.

[0021] Modified polypropylene fiber serves as a skeleton, providing mechanical strength and a fluid-guiding channel. Modified plant fiber acts as an antibacterial carrier. Through blending and hot pressing, a fluffy, three-dimensional, interwoven fluid-guiding and antibacterial layer is formed. Finally, the permeable surface layer, fluid-guiding and antibacterial layer, absorbent core, and breathable base layer are laminated and bonded. Dotted hot-melt adhesive bonding ensures a stable, breathable channel between the permeable surface layer, fluid-guiding and antibacterial layer, and absorbent core. Heat-pressing the edges prevents side leakage while maintaining structural elasticity.

[0022] As a preferred technical solution of the present invention, in step (I), the inclusion compound is prepared by the following method:

[0023] Tea polyphenols and salicylic acid are added to deionized water, stirred and heated to obtain a core material solution; β-cyclodextrin is added to the core material solution, stirred and heated, then cooled to a precipitation temperature and kept warm to form a precipitate, which is filtered and freeze-dried to obtain the inclusion compound.

[0024] In some optional examples, the mass ratio of tea polyphenols to salicylic acid is (3.5-4.5):1, for example, it can be 3.5:1, 3.6:1, 3.7:1, 3.8:1, 3.9:1, 4.0:1, 4.1:1, 4.2:1, 4.3:1, 4.4:1 or 4.5:1, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0025] The present invention specifically limits the mass ratio of tea polyphenols to salicylic acid to (3.5-4.5):1. Within this range, the strong broad-spectrum antibacterial property of tea polyphenols (destroying bacterial cell membranes) and the penetration enhancement and anti-inflammatory effects of salicylic acid form functional complementarity. Tea polyphenols first destroy the surface structure of the bacteria, creating a channel for salicylic acid to penetrate deeply into the bacteria and interfere with the metabolic pathway, thereby significantly improving the comprehensive antibacterial efficiency. At the same time, within this mass ratio range, the optimal cavity filling rate can be achieved during the β-cyclodextrin inclusion process. The molecular weight of tea polyphenols is relatively large and needs to occupy more cyclodextrin space, while the salicylic acid molecules are relatively small and can fill the gaps, ensuring that the inclusion complex has a compact structure and optimal thermal stability.

[0026] When the amount of tea polyphenols added is lower than the lower limit of the range defined in the present invention, the membrane destruction ability is insufficient, and the antibacterial efficacy of salicylic acid drops sharply due to the inability to effectively penetrate the intact bacterial membrane; at the same time, the inclusion structure becomes loose due to insufficient filling of tea polyphenols, and salicylic acid molecules are easy to escape from the cyclodextrin cavity, and are easily volatilized and lost during processing and storage; in addition, too low an amount of tea polyphenols added will also lead to a weakening of the antioxidant capacity of the system, affecting the long-term stability of the active ingredients.

[0027] When the amount of tea polyphenols added is higher than the upper limit of the range defined by the present invention, the excess tea polyphenols cannot be effectively encapsulated by cyclodextrin, and part of the tea polyphenols will be exposed to the outside of the inclusion complex, making it more susceptible to oxidation and inactivation during hot pressing or storage; at the same time, high concentrations of tea polyphenols will competitively adsorb on the bacterial surface, hindering the contact between salicylic acid and bacteria, and weakening the synergistic effect between salicylic acid and tea polyphenols; in addition, excess tea polyphenols will also interfere with the cationic antibacterial pathway of chitosan quaternary ammonium salt, reducing the overall antibacterial efficiency.

[0028] In some optional examples, the temperature for stirring and heating the tea polyphenols, salicylic acid and deionized water is 45-55°C, for example, it can be 45°C, 46°C, 47°C, 48°C, 49°C, 50°C, 51°C, 52°C, 53°C, 54°C or 55°C, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0029] In some optional examples, the stirring and heating time of the tea polyphenols, salicylic acid and deionized water is 25 to 35 minutes, for example, it can be 25 minutes, 26 minutes, 27 minutes, 28 minutes, 29 minutes, 30 minutes, 31 minutes, 32 minutes, 33 minutes, 34 minutes or 35 minutes, but is not limited to the listed values, and other values ​​not listed within this numerical range are also applicable.

[0030] In some optional examples, the total mass fraction of tea polyphenols and salicylic acid in the core material solution is 1.5 to 2.5 wt%, for example, it can be 1.5 wt%, 1.6 wt%, 1.7 wt%, 1.8 wt%, 1.9 wt%, 2.0 wt%, 2.1 wt%, 2.2 wt%, 2.3 wt%, 2.4 wt% or 2.5 wt%, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0031] In some optional examples, the ratio of the total mass of tea polyphenols and salicylic acid in the core material solution to the mass of β-cyclodextrin is 1:(3-5), for example, it can be 1:3.0, 1:3.2, 1:3.4, 1:3.6, 1:3.8, 1:4.0, 1:4.2, 1:4.4, 1:4.6, 1:4.8 or 1:5.0, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0032] The present invention specifically limits the ratio of the total mass of tea polyphenols and salicylic acid in the core material solution to the mass of β-cyclodextrin to 1:(3-5). Within this range, it can be ensured that the β-cyclodextrin cavity is fully filled, and the cyclodextrin molecules can just completely encapsulate the active substance to form a tight host-guest structure, thereby maximizing the thermal stability of the inclusion complex; at the same time, the cyclodextrin hydrophobic cavity fully accommodates the tea polyphenol benzene ring and salicylic acid molecules, which are stably bound by van der Waals forces, preventing the volatilization and escape of salicylic acid and shielding the oxidative degradation of tea polyphenols, while maintaining the sustained-release properties. The inclusion structure gradually dissociates under liquid infiltration, achieving long-term antibacterial effect.

[0033] When the amount of β-cyclodextrin added is lower than the lower limit of the range defined in the present invention, the number of cyclodextrin cavities is insufficient to encapsulate all active molecules, resulting in some tea polyphenols and salicylic acid being free. The unencapsulated tea polyphenols are easily oxidized and inactivated when exposed to a high-temperature processing environment, and their antibacterial efficacy is greatly attenuated; the unencapsulated salicylic acid is rapidly lost during hot pressing or storage due to the high volatility of the molecule, and is quickly released at the initial stage of use, losing its sustained-release function.

[0034] When the amount of β-cyclodextrin added exceeds the upper limit of the range specified in this invention, the excess cyclodextrin molecules cannot effectively bind to the active ingredient, resulting in a large amount of "empty" cyclodextrin. These empty molecules will competitively adsorb on the surface of the plant fiber during subsequent processing, hindering the effective bonding of the modified plant fiber and the polypropylene fiber, and weakening the structural strength of the diversion and antibacterial layer. Furthermore, the excess cyclodextrin takes up space in the antibacterial solution, diluting the concentration of the effective antibacterial ingredients and reducing the antibacterial efficiency per unit area. During the sustained-release process, the empty cyclodextrin will prematurely absorb water, interfering with the normal dissociation of the inclusion complex and resulting in uneven release of antibacterial activity.

[0035] In some optional examples, the temperature for stirring and heating the core material solution and β-cyclodextrin is 50-60°C, for example, it can be 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, 56°C, 57°C, 58°C, 59°C or 60°C, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0036] In some optional examples, the stirring and heating time of the core material solution and β-cyclodextrin is 1.5 to 2.5 hours, for example, it can be 1.5 hours, 1.6 hours, 1.7 hours, 1.8 hours, 1.9 hours, 2.0 hours, 2.1 hours, 2.2 hours, 2.3 hours, 2.4 hours or 2.5 hours, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0037] In some optional examples, the precipitation temperature is 4 to 6°C, for example, it can be 4.0°C, 4.2°C, 4.4°C, 4.6°C, 4.8°C, 5.0°C, 5.2°C, 5.4°C, 5.6°C, 5.8°C or 6.0°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0038] In some optional embodiments, the temperature is kept at the precipitation temperature for 2 to 3 hours, for example, 2.0 hours, 2.1 hours, 2.2 hours, 2.3 hours, 2.4 hours, 2.5 hours, 2.6 hours, 2.7 hours, 2.8 hours, 2.9 hours or 3.0 hours, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0039] It should be noted that the present invention does not impose any specific requirements or special limitations on the freeze-drying temperature and time. For example, the freeze-drying temperature is -40 to -50°C, for example, -40°C, -41°C, -42°C, -43°C, -44°C, -45°C, -46°C, -47°C, -48°C, -49°C or -50°C. The freeze-drying time is 12 to 24 hours, for example, 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20 hours, 21 hours, 22 hours, 23 hours or 24 hours, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0040] As a preferred technical solution of the present invention, in step (I), the liposome is prepared by the following method:

[0041] Lecithin is added to anhydrous ethanol, stirred and heated to obtain a lecithin solution; chamomile extract is added to PBS buffer, stirred and heated to obtain a chamomile extract solution; under stirring, the chamomile extract solution is dropped into the lecithin solution, and after all the chamomile extract is dropped, the obtained mixed solution is stirred at high speed to obtain a suspension; the suspension is subjected to rotary evaporation to remove ethanol, and then ultrafiltration is performed, and the retentate is collected and freeze-dried to obtain the liposome.

[0042] The present invention adds lecithin to anhydrous ethanol and heats and dissolves it to form a high-concentration homogeneous solution, allowing the lecithin molecules to fully stretch and lay the foundation for subsequent liposome self-assembly; then, a chamomile extract solution is dropped into the lecithin ethanol solution, forming a water / alcohol mixed system under stirring conditions, prompting the amphiphilic lecithin molecules to spontaneously align in an oriented manner, with their hydrophilic heads facing the aqueous phase and their hydrophobic tails encapsulating the oil-soluble chamomile components, to initially form a pre-liposome structure. Subsequently, high-speed stirring is performed, and the pre-liposomes are broken into nanoscale vesicles with uniform particle size by strong mechanical action, ensuring that the chamomile extract is effectively encapsulated in a closed chamber composed of a phospholipid bilayer. Subsequently, ethanol is gently removed by rotary evaporation to avoid high-temperature destruction of the active ingredient, while promoting further close arrangement of the phospholipid molecules and enhancing the stability of the liposome structure. Unencapsulated small molecule impurities and free components are removed by ultrafiltration, significantly improving the encapsulation efficiency and product purity. Finally, trehalose is added to the retentate and freeze-dried. During the dehydration process, trehalose replaces water molecules and binds to phospholipids, forming a glassy protective layer that effectively prevents the liposome membrane from rupturing during drying. The resulting liposomes have a complete liposomal structure, suitable for long-term storage, and can slowly release the chamomile active ingredients during use, achieving long-term soothing and antibacterial effects.

[0043] In some optional embodiments, the temperature for stirring and heating the lecithin and anhydrous ethanol is 60-70°C, for example, 60°C, 61°C, 62°C, 63°C, 64°C, 65°C, 66°C, 67°C, 68°C, 69°C or 70°C, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0044] It should be noted that the present invention does not impose any specific requirements or special restrictions on the time for stirring and heating lecithin and anhydrous ethanol. The stirring is performed until the lecithin is completely dissolved. Generally, the time for stirring and heating lecithin and anhydrous ethanol is controlled to be 30 to 40 minutes. Of course, those skilled in the art can appropriately shorten or extend the stirring time according to experimental needs and operating environment.

[0045] In some optional examples, the mass fraction of lecithin in the lecithin solution is 18 to 22 wt%, for example, it can be 18 wt%, 18.5 wt%, 19 wt%, 19.5 wt%, 20 wt%, 20.5 wt%, 21 wt%, 21.5 wt% or 22 wt%, but is not limited to the listed values, and other values ​​not listed within this numerical range are also applicable.

[0046] In some optional embodiments, the temperature for stirring and heating the chamomile extract and PBS buffer is 40-50°C, for example, 40°C, 41°C, 42°C, 43°C, 44°C, 45°C, 46°C, 47°C, 48°C, 49°C or 50°C, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0047] It should be noted that the present invention does not impose any specific requirements or special limitations on the stirring and heating time of the chamomile extract and the PBS buffer solution. The stirring is sufficient until the chamomile extract is evenly dispersed. Generally, the stirring and heating time of the chamomile extract and the PBS buffer solution is controlled to be 20 to 30 minutes. Of course, those skilled in the art can appropriately shorten or extend the stirring time according to experimental needs and operating environment.

[0048] In some optional examples, the mass fraction of chamomile extract in the chamomile extract solution is 8 to 12 wt%, for example, it can be 8.0 wt%, 8.5 wt%, 9.0 wt%, 9.5 wt%, 10.0 wt%, 10.5 wt%, 11.0 wt%, 11.5 wt% or 12.0 wt%, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0049] In some optional examples, the mass ratio of the chamomile extract in the chamomile extract solution to the lecithin in the lecithin solution is 1:(1.5-2.5), for example, it can be 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:2.0, 1:2.1, 1:2.2, 1:2.3, 1:2.4 or 1:2.5, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0050] The present invention specifically limits the mass ratio of chamomile extract in the chamomile extract solution to lecithin in the lecithin solution to 1:(1.5~2.5). Within this range, lecithin can form a complete monolayer membrane to wrap the chamomile extract molecules, ensuring a tight structure of the nanovesicles; at the same time, the hydrophilic head and hydrophobic tail of lecithin are arranged in a directionally arranged manner, completely sealing the heat-sensitive components of the chamomile extract in the hydrophobic cavity of the liposome, effectively blocking the damage to the active substance caused by high processing temperature; in addition, the dense phospholipid layer can also control the sustained-release rate, achieving long-lasting soothing and antibacterial effects during use.

[0051] When the amount of lecithin used falls below the lower limit of the range defined herein, the phospholipid molecules are insufficient to completely encapsulate the chamomile extract, resulting in a significant decrease in the encapsulation efficiency. The unencapsulated active ingredient is directly exposed to the subsequent process environment, resulting in significant volatilization losses during the rotary evaporation stage due to lack of protection, and degradation and inactivation due to ice crystal compression during freeze-drying. More seriously, the phospholipid membrane, resulting from insufficient molecular coverage, forms structural defects, making the liposomes prone to fusion and rupture during storage, affecting the antibacterial effect of the product.

[0052] When the amount of lecithin used exceeds the upper limit of the range defined by the present invention, the excess phospholipid molecules will self-assemble to form blank vesicles. The blank vesicles not only dilute the concentration of the active ingredient, but also adsorb on the surface of the plant fiber, hindering the binding of the plant fiber to other active components in the antibacterial solution. During the sustained-release phase, the excess phospholipid layer excessively blocks the release of the active ingredient, resulting in the chamomile extract components being unable to penetrate the site of action in a timely manner. In addition, high concentrations of lecithin easily cause vesicle aggregation, resulting in an increase in the particle size of the liposomes, making it difficult for them to penetrate the fiber micropores and reducing the functional uniformity of the diversion and antibacterial layer.

[0053] In some optional examples, the dripping rate of the chamomile extract solution is 3 to 5 mL / min, for example, it can be 3.0 mL / min, 3.2 mL / min, 3.4 mL / min, 3.6 mL / min, 3.8 mL / min, 4.0 mL / min, 4.2 mL / min, 4.4 mL / min, 4.6 mL / min, 4.8 mL / min or 5.0 mL / min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0054] In some optional examples, the rotation speed of the high-speed stirring is 3000-4000 rpm, for example, it can be 3000 rpm, 3100 rpm, 3200 rpm, 3300 rpm, 3400 rpm, 3500 rpm, 3600 rpm, 3700 rpm, 3800 rpm, 3900 rpm or 4000 rpm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0055] In some optional examples, the high-speed stirring time is 5 to 8 minutes, for example, it can be 5.0 minutes, 5.2 minutes, 5.4 minutes, 5.6 minutes, 5.8 minutes, 6.0 minutes, 6.2 minutes, 6.4 minutes, 6.6 minutes, 6.8 minutes, 7.0 minutes, 7.2 minutes, 7.4 minutes, 7.6 minutes, 7.8 minutes or 8.0 minutes, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0056] In some optional examples, the temperature of rotary evaporation of the suspension is 40-50°C, for example, it can be 40°C, 41°C, 42°C, 43°C, 44°C, 45°C, 46°C, 47°C, 48°C, 49°C or 50°C, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0057] In some optional examples, the rotary evaporation time of the suspension is 30 to 40 minutes, for example, it can be 30 minutes, 31 minutes, 32 minutes, 33 minutes, 34 minutes, 35 minutes, 36 minutes, 37 minutes, 38 minutes, 39 minutes or 40 minutes, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0058] In some optional examples, the ultrafiltration membrane used in the ultrafiltration has a molecular weight cutoff of 10 kDa.

[0059] In some optional examples, trehalose is added to the retentate, and the amount of trehalose added is 7 to 9 wt% of the mass of the retentate, for example, it can be 7.0 wt%, 7.2 wt%, 7.4 wt%, 7.6 wt%, 7.8 wt%, 8.0 wt%, 8.2 wt%, 8.4 wt%, 8.6 wt%, 8.8 wt% or 9.0 wt%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0060] It should be noted that the present invention does not impose any specific requirements or special limitations on the freeze-drying temperature and time. For example, the freeze-drying temperature is -40 to -50°C, for example, -40°C, -41°C, -42°C, -43°C, -44°C, -45°C, -46°C, -47°C, -48°C, -49°C or -50°C. The freeze-drying time is 12 to 24 hours, for example, 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20 hours, 21 hours, 22 hours, 23 hours or 24 hours, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0061] As a preferred technical solution of the present invention, in step (I), the mass fraction of the inclusion complex in the antibacterial solution is 1.3 to 1.5 wt%, for example, it can be 1.3 wt%, 1.32 wt%, 1.34 wt%, 1.36 wt%, 1.38 wt%, 1.4 wt%, 1.42 wt%, 1.44 wt%, 1.46 wt%, 1.48 wt% or 1.5 wt%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0062] In some optional examples, the mass fraction of liposomes in the antibacterial liquid is 0.8 to 1.2 wt%, for example, it can be 0.8 wt%, 0.85 wt%, 0.9 wt%, 0.95 wt%, 1 wt%, 1.05 wt%, 1.1 wt%, 1.15 wt% or 1.2 wt%, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0063] In some optional examples, the mass fraction of the chitosan quaternary ammonium salt in the antibacterial solution is 0.4 to 0.6 wt%, for example, it can be 0.4 wt%, 0.42 wt%, 0.44 wt%, 0.46 wt%, 0.48 wt%, 0.5 wt%, 0.52 wt%, 0.54 wt%, 0.56 wt%, 0.58 wt% or 0.6 wt%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0064] As a preferred technical solution of the present invention, step (II), the operation steps of modifying the polypropylene fiber with a silane coupling agent include:

[0065] The polypropylene fiber is immersed in a silane coupling agent solution, heated and shaken, and then the fiber is taken out, washed, and dried to obtain a silane-modified fiber.

[0066] It should be noted that the silane coupling agent solution needs to be prepared and used immediately. The silane coupling agent is dispersed in an ethanol aqueous solution, mixed and stirred for a period of time to allow the silane coupling agent to be fully hydrolyzed, and then the polypropylene fiber is immersed in the silane coupling agent solution.

[0067] In some optional examples, the mass fraction of the silane coupling agent in the silane coupling agent solution is 2.5 to 3.5 wt%, for example, it can be 2.5 wt%, 2.6 wt%, 2.7 wt%, 2.8 wt%, 2.9 wt%, 3.0 wt%, 3.1 wt%, 3.2 wt%, 3.3 wt%, 3.4 wt% or 3.5 wt%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0068] In some optional examples, the mass ratio of the polypropylene fiber to the silane coupling agent in the silane coupling agent solution is 100:(1.5-2.5), for example, it can be 100:1.5, 100:1.6, 100:1.7, 100:1.8, 100:1.9, 100:2.0, 100:2.1, 100:2.2, 100:2.3, 100:2.4 or 100:2.5, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0069] In some optional examples, the heating temperature of the heated oscillation of the polypropylene fiber and the silane coupling agent solution is 40-50°C, for example, it can be 40°C, 41°C, 42°C, 43°C, 44°C, 45°C, 46°C, 47°C, 48°C, 49°C or 50°C, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0070] In some optional examples, the heating time of the heating oscillation of the polypropylene fiber and the silane coupling agent solution is 2.5 to 3.5 hours, for example, it can be 2.5 hours, 2.6 hours, 2.7 hours, 2.8 hours, 2.9 hours, 3.0 hours, 3.1 hours, 3.2 hours, 3.3 hours, 3.4 hours or 3.5 hours, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0071] In some optional examples, the oscillation speed of the heated oscillation of the polypropylene fiber and the silane coupling agent solution is 120 to 150 rpm, for example, it can be 120 rpm, 125 rpm, 130 rpm, 135 rpm, 140 rpm, 145 rpm or 150 rpm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0072] As a preferred technical solution of the present invention, step (II), the method for preparing the modified polypropylene fiber comprises:

[0073] Chitosan is dissolved in an acetic acid aqueous solution to obtain a chitosan solution, and an alkali solution is added dropwise to the chitosan solution to adjust the pH value thereof; a silane-modified fiber is immersed in the chitosan solution, and after being immersed in a negative pressure environment and oscillation conditions for a period of time and then restored to normal pressure, the fiber is taken out and immersed in a genipin solution for heating and cross-linking; and finally, the modified polypropylene fiber is obtained after filtering, washing and drying.

[0074] The preparation method of the modified polypropylene fiber provided by the present invention solves the technical problem that the surface inertia of polypropylene fiber is strong and difficult to stably graft functional molecules, and is first modified by a silane coupling agent. Under 40-50 DEG C of heating and oscillation conditions, the silanol group (-Si-OH) produced by its hydrolysis is anchored on the surface of polypropylene fiber by hydrogen bond or van der Waals force, and its organic functional group (such as amino group) is exposed outward, so that the polypropylene surface is loaded with a large number of active reaction sites. In the chitosan grafting modification process, by negative pressure environment and oscillation, the chitosan solution is prompted to penetrate deeply into the fiber micropores, so that the chitosan molecular chain is fully exposed to the active group exposed by the silane layer, and the genipin cross-linking agent reacts specifically with the amino group of chitosan to form a covalent cross-linked network, which fixes the chitosan molecules on the fiber surface and in the pores. The modified polypropylene fiber prepared by the modification method provided by the present invention not only gives the fiber lasting hydrophilicity, but also constructs a stable antibacterial surface by the cationic antibacterial effect of the chitosan quaternary ammonium salt.

[0075] In some optional examples, the mass fraction of the acetic acid aqueous solution is 1 to 1.5 wt%, for example, it can be 1.0 wt%, 1.05 wt%, 1.1 wt%, 1.15 wt%, 1.2 wt%, 1.25 wt%, 1.3 wt%, 1.35 wt%, 1.4 wt%, 1.45 wt% or 1.5 wt%, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0076] In some optional examples, the mass fraction of chitosan in the chitosan solution is 2.5 to 3.5 wt%, for example, it can be 2.5 wt%, 2.6 wt%, 2.7 wt%, 2.8 wt%, 2.9 wt%, 3.0 wt%, 3.1 wt%, 3.2 wt%, 3.3 wt%, 3.4 wt% or 3.5 wt%, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0077] The present invention specifically limits the mass fraction of chitosan in the chitosan solution to 2.5-3.5wt%. Within this range, the chitosan molecular chains are fully extended in the aqueous solution to form a solution with moderate viscosity, which can not only deeply penetrate into the fiber micropores but also evenly cover the fiber surface during the negative pressure oscillation process; at the same time, a sufficient amount of free amino groups (-NH2) can ensure full bonding with the silane modified layer and provide sufficient reaction sites for genipin cross-linking, ultimately forming a dense cross-linked network with a thickness of about 0.5-1μm, giving the fiber lasting hydrophilicity and stable antibacterial properties.

[0078] When the concentration of the chitosan solution is lower than 2.5wt%, the number of chitosan molecules is insufficient to effectively cover the silane-activated fiber surface, and some active sites are not occupied, resulting in a decrease in the chitosan grafting rate; in addition, insufficient chitosan causes the formed chitosan layer to be too thin and discontinuous. After cross-linking with genipin, the chitosan layer is sparse, and local peeling is prone to occur during the subsequent hot pressing process, seriously affecting the hydrophilicity and antibacterial properties.

[0079] When the concentration of the chitosan solution is higher than 3.5wt%, the viscosity of the chitosan solution increases significantly, and it is difficult to penetrate into the internal pores of the fiber under negative pressure, and can only form a thick and uneven gel-like accumulation layer on the surface; in addition, the excessive chitosan molecular chains are entangled with each other, hindering the diffusion and reaction efficiency of the genipin cross-linker, resulting in insufficient cross-linking degree, and the surface chitosan is easy to swell and fall off, blocking the pores of the diversion and antibacterial layer, affecting the air permeability of the product.

[0080] In some optional embodiments, 0.1 M alkali solution is added dropwise to the chitosan solution to adjust its pH value to 5.2-5.6, for example, 5.2, 5.25, 5.3, 5.35, 5.4, 5.45, 5.5, 5.55 or 5.6, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0081] In some optional examples, the ratio of the silane-modified fiber to the chitosan solution is 1g:(20-30)mL, for example, it can be 1g:20mL, 1g:21mL, 1g:22mL, 1g:23mL, 1g:24mL, 1g:25mL, 1g:26mL, 1g:27mL, 1g:28mL, 1g:29mL or 1g:30mL, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0082] In some optional examples, the vacuum degree of the negative pressure environment is -0.06 to -0.08 MPa, for example, it can be -0.06 MPa, -0.062 MPa, -0.064 MPa, -0.066 MPa, -0.068 MPa, -0.07 MPa, -0.072 MPa, -0.074 MPa, -0.076 MPa, -0.078 MPa or -0.08 MPa, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0083] In some optional examples, the oscillation speed is 100-120 rpm, for example, it can be 100 rpm, 102 rpm, 104 rpm, 106 rpm, 108 rpm, 110 rpm, 112 rpm, 114 rpm, 116 rpm, 118 rpm or 120 rpm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0084] In some optional examples, the immersion time of the silane-modified fiber in the chitosan solution is 30 to 40 minutes, for example, it can be 30 minutes, 31 minutes, 32 minutes, 33 minutes, 34 minutes, 35 minutes, 36 minutes, 37 minutes, 38 minutes, 39 minutes or 40 minutes, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0085] In some optional examples, the mass fraction of the genipin solution is 0.5-0.7wt%, for example, it can be 0.5wt%, 0.52wt%, 0.54wt%, 0.56wt%, 0.58wt%, 0.6wt%, 0.62wt%, 0.64wt%, 0.66wt%, 0.68wt% or 0.7wt%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0086] In some optional examples, the heating cross-linking temperature is 50-60°C, for example, it can be 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, 56°C, 57°C, 58°C, 59°C or 60°C, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0087] In some optional examples, the heating cross-linking time is 1.5 to 2.5 hours, for example, it can be 1.5 hours, 1.6 hours, 1.7 hours, 1.8 hours, 1.9 hours, 2.0 hours, 2.1 hours, 2.2 hours, 2.3 hours, 2.4 hours or 2.5 hours, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0088] As a preferred technical solution of the present invention, in step (III), the plant fibers include bamboo fibers, hemp fibers and kapok fibers.

[0089] The present invention adopts a combination of bamboo fiber, hemp fiber and kapok fiber as a carrier of antibacterial active components. The bamboo fiber provides basic antibacterial activity and forms a liquid diversion channel by virtue of its natural bamboo quinone component and longitudinal through-holes; the hollow structure and ultra-high specific surface area of ​​the hemp fiber give the diversion and antibacterial layer excellent moisture absorption and air permeability, while its rigid skeleton enhances the compressive strength of the diversion and antibacterial layer; the kapok fiber fills the fiber gaps with an ultra-fine diameter and natural curling form to form nano-scale pores, thereby increasing the load density of the antibacterial components. At the same time, its silky touch improves the comfort of use.

[0090] In some optional examples, the mass ratio of the bamboo fiber, hemp fiber and kapok fiber is 1:(0.4-0.5):(0.2-0.3), for example, it can be 1:0.4:0.2, 1:0.41:0.21, 1:0.42:0.22, 1:0.43:0.23, 1:0.44:0.24, 1:0.45:0.25, 1:0.46:0.26, 1:0.47:0.27, 1:0.48:0.28, 1:0.49:0.29 or 1:0.5:0.3, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0091] In some optional examples, the immersion temperature of the plant fiber in the antibacterial liquid is 40-50°C, for example, it can be 40°C, 41°C, 42°C, 43°C, 44°C, 45°C, 46°C, 47°C, 48°C, 49°C or 50°C, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0092] In some optional examples, the immersion time of the plant fiber in the antibacterial liquid is 25 to 35 minutes, for example, it can be 25 minutes, 26 minutes, 27 minutes, 28 minutes, 29 minutes, 30 minutes, 31 minutes, 32 minutes, 33 minutes, 34 minutes or 35 minutes, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0093] As a preferred technical solution of the present invention, step (III), the operation steps of the blended hot pressing include:

[0094] The modified plant fiber is fed into an opening machine for opening, the opened modified plant fiber is mixed with modified polypropylene fiber to obtain mixed fiber, the mixed fiber is dispersed in water to form a fiber suspension, the fiber suspension is fed into an inclined mesh wet-laid web forming machine for wet-laid web forming to obtain a fiber web; an adhesive is sprayed on the surface of the fiber web, and then hot pressing is performed to obtain the diversion and antibacterial layer.

[0095] In some optional examples, the mass ratio of the modified plant fiber to the modified polypropylene fiber is (2-3):1, for example, it can be 2.0:1, 2.1:1, 2.2:1, 2.3:1, 2.4:1, 2.5:1, 2.6:1, 2.7:1, 2.8:1, 2.9:1 or 3.0:1, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0096] The present invention specifically limits the mass ratio of modified plant fiber to modified polypropylene fiber to (2-3):1. Within this range, the modified plant fiber, with its natural porous structure and ultra-large specific surface area, can efficiently load the β-cyclodextrin inclusion complex, liposomes and chitosan quaternary ammonium salt in the antibacterial liquid to form a stable sustained-release antibacterial composite material. Tea polyphenols and salicylic acid synergistically destroy the bacterial structure, chamomile extract is used to soothe the skin, and chitosan quaternary ammonium salt cationic antibacterial, achieving long-lasting antibacterial protection. At the same time, the inherent hydrophilicity and capillary effect of the plant fiber can assist the rapid infiltration of liquid. The modified polypropylene fiber plays a skeleton role. After being double-modified with silane-chitosan, the abundant hydrophilic groups on the surface form high-speed diversion channels, allowing the liquid to quickly diffuse laterally and be introduced into the absorbent core to avoid surface residue. At the same time, its high mechanical strength can support the fluffy three-dimensional interwoven structure, ensuring that sufficient porosity is maintained after hot pressing, effectively discharging moisture and inhibiting bacterial growth.

[0097] When the amount of modified plant fiber added is lower than the lower limit of the range defined in the present invention, it means that the modified polypropylene fiber is added in excess, which will result in, on the one hand, a reduction in the number of antibacterial component loading sites, and insufficient total amount of antibacterial active substances, which will greatly reduce the antibacterial rate of the diversion and antibacterial layer; on the other hand, the overly rigid modified polypropylene fiber will compress the pore space, resulting in a decrease in the porosity of the diversion and antibacterial layer after blending and hot pressing, affecting the air permeability, forming a humid and hot environment, and causing bacterial growth; on the other hand, due to the low proportion of modified plant fiber added, the flexibility of the diversion and antibacterial layer is reduced, and the friction discomfort during use is significantly increased, affecting the user experience.

[0098] When the amount of modified plant fiber added is higher than the upper limit of the range specified in the present invention, although the excess fluffy fiber increases the loading amount of the antibacterial active ingredients, due to the lack of sufficient modified polypropylene fiber as support, the compressive strength of the diversion and antibacterial layer decreases, and irreversible structural collapse occurs. The collapsed structure will hinder air circulation, affecting air permeability, forming a humid and hot environment, and causing bacterial growth.

[0099] It should be noted that the present invention does not impose any specific requirements or restrictions on the process parameters of the blended hot pressing. For example:

[0100] In some optional instances, the speed of the opener is 2500-3000 rpm, for example, it can be 2500 rpm, 2550 rpm, 2600 rpm, 2650 rpm, 2700 rpm, 2750 rpm, 2800 rpm, 2850 rpm, 2900 rpm, 2950 rpm or 3000 rpm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0101] In some optional embodiments, the opening time is 10 to 15 minutes, for example, it can be 10 minutes, 10.5 minutes, 11 minutes, 11.5 minutes, 12 minutes, 12.5 minutes, 13 minutes, 13.5 minutes, 14 minutes, 14.5 minutes or 15 minutes, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0102] In some optional examples, the mass fraction of the mixed fibers in the fiber suspension is 0.4 to 0.6 wt%, for example, it can be 0.4 wt%, 0.42 wt%, 0.44 wt%, 0.46 wt%, 0.48 wt%, 0.5 wt%, 0.52 wt%, 0.54 wt%, 0.56 wt%, 0.58 wt% or 0.6 wt%, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0103] In some optional embodiments, the mesh size of the inclined-wire wet-laid web forming machine is 120 to 150 mesh, for example, it can be 120 mesh, 125 mesh, 130 mesh, 135 mesh, 140 mesh, 145 mesh or 150 mesh, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0104] In some optional examples, the vacuum degree of wet-laid web formation is -0.03 to -0.04 MPa, for example, it can be -0.03 MPa, -0.031 MPa, -0.032 MPa, -0.033 MPa, -0.034 MPa, -0.035 MPa, -0.036 MPa, -0.037 MPa, -0.038 MPa, -0.039 MPa or -0.04 MPa, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0105] In some optional examples, the wet-laid web speed is 15 to 25 m / min, for example, it can be 15 m / min, 16 m / min, 17 m / min, 18 m / min, 19 m / min, 20 m / min, 21 m / min, 22 m / min, 23 m / min, 24 m / min or 25 m / min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0106] In some optional embodiments, the basis weight of the web is 45 to 55 g / m 2 , for example, it can be 45g / m 2 , 46g / m 2 , 47g / m 2 , 48g / m 2 , 49g / m 2 , 50g / m 2 , 51g / m 2 , 52g / m 2 , 53g / m 2 , 54g / m 2 or 55g / m 2 , but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0107] In some optional embodiments, the spraying amount of the adhesive is 8 to 12 g / m 2 The fiber web, for example, can be 8.0g / m 2 Fiber web, 8.5g / m 2 Fiber web, 9.0g / m 2 Fiber web, 9.5g / m 2 Fiber web, 10.0g / m 2 Fiber web, 10.5g / m 2 Fiber web, 11.0g / m 2 Fiber web, 11.5g / m 2 Fiber web or 12.0g / m 2 The fiber web is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0108] In some optional examples, the adhesive is copolyester hot melt adhesive powder.

[0109] In some optional embodiments, the hot pressing temperature is 120-130°C, for example, it can be 120°C, 121°C, 122°C, 123°C, 124°C, 125°C, 126°C, 127°C, 128°C, 129°C or 130°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0110] In some optional examples, the hot pressing pressure is 30 to 40 kPa, for example, it can be 30 kPa, 31 kPa, 32 kPa, 33 kPa, 34 kPa, 35 kPa, 36 kPa, 37 kPa, 38 kPa, 39 kPa or 40 kPa, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0111] In some optional examples, the hot pressing time is 20 to 30 seconds, for example, it can be 20 seconds, 21 seconds, 22 seconds, 23 seconds, 24 seconds, 25 seconds, 26 seconds, 27 seconds, 28 seconds, 29 seconds or 30 seconds, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0112] As a preferred technical solution of the present invention, in step (IV), the liquid-permeable surface layer, the diversion and antibacterial layer, the absorbent core and the breathable bottom layer are bonded by point-like hot melt adhesive bonding, and the edges are heat-pressed and sealed.

[0113] It should be noted that the core innovation of the technical solution of the present invention lies in the construction of a diversion and antibacterial layer with long-lasting antibacterial properties, efficient flow diversion, and breathable properties through specific material modification (β-cyclodextrin inclusion, plant fiber loading, and polypropylene fiber grafting modification) and wet-laid web formation. This innovative structure has universal adaptability and can work in conjunction with other functional layers of various conventional sanitary napkins. The scope of protection of the present invention should not be limited by the conventional technical selection of the bonding method and operating conditions of each functional layer, as well as the structure, material, performance parameters, and preparation process of other functional layers besides the diversion and antibacterial layer.

[0114] Therefore, on the one hand, no specific requirements or special limitations are imposed on the bonding process and operating conditions of the liquid-permeable surface layer, the diversion and antibacterial layer, the absorbent core, and the breathable bottom layer. Any bonding method commonly used in the art can achieve the claimed technical effects of breathability, antibacterial properties, and moisture absorption of the present invention. To help those skilled in the art better implement the technical solution of the present invention and achieve the most ideal technical effects, the present invention provides an exemplary description of the bonding process and operating conditions, which does not serve as a further limitation on the technical solution of the present invention:

[0115] In some optional examples, the liquid-permeable surface layer, the diversion and antibacterial layer, the absorbent core and the breathable bottom layer are bonded by point-shaped hot melt adhesive bonding, and the edges are heat-pressed and sealed.

[0116] In some optional embodiments, the amount of glue sprayed for point-shaped hot melt adhesive bonding is 5 to 7 g / m 2 , for example, it can be 5.0g / m 2 , 5.2g / m 2 , 5.4g / m 2 , 5.6g / m 2 , 5.8g / m 2 , 6.0g / m 2 , 6.2g / m 2 , 6.4g / m 2 , 6.6g / m 2 , 6.8g / m 2 or 7.0g / m 2 , but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0117] In some optional embodiments, the temperature of hot pressing sealing is 120-130°C, for example, it can be 120°C, 121°C, 122°C, 123°C, 124°C, 125°C, 126°C, 127°C, 128°C, 129°C or 130°C, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0118] In some optional examples, the pressure of hot pressing and sealing is 30-40 kPa, for example, it can be 30 kPa, 31 kPa, 32 kPa, 33 kPa, 34 kPa, 35 kPa, 36 kPa, 37 kPa, 38 kPa, 39 kPa or 40 kPa, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0119] In some optional examples, the hot pressing sealing time is 3 to 5 seconds, for example, it can be 3.0 seconds, 3.2 seconds, 3.4 seconds, 3.6 seconds, 3.8 seconds, 4.0 seconds, 4.2 seconds, 4.4 seconds, 4.6 seconds, 4.8 seconds or 5.0 seconds, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0120] On the other hand, for other functional layers of the sanitary napkin, such as the liquid-permeable surface layer, absorbent core, breathable backing layer, and release film defined herein, their material selection, structural characteristics, and preparation processes are not limiting features of the present invention. Those skilled in the art may implement these functional layers using existing technical solutions based on actual needs. When using liquid-permeable surface layers, absorbent cores, breathable backing layers, or release film structures known in the art, even if their specific implementations are not fully enumerated in this specification, as long as they are combined with the antibacterial and antimicrobial layer of the present invention to form a complete sanitary napkin structure, they are considered to fall within the scope of protection of the present invention.

[0121] To help those skilled in the art better implement the technical solution of the present invention and achieve the most ideal technical effect, the present invention provides an exemplary description of the main performance indicators or preparation processes of the liquid-permeable surface layer, the absorbent core, and the breathable backing layer, but this does not serve as a further limitation of the technical solution of the present invention. The details are as follows:

[0122] In some optional embodiments, the liquid permeable surface layer is made of spunbond nonwoven fabric with a unit weight of 25 to 35 g / m 2 The pore size distribution is 80-150 μm, the liquid penetration time is ≤3s, the back permeation amount is ≤0.5g, and the raw material is preferably polypropylene or polyethylene / polypropylene composite fiber.

[0123] In some optional embodiments, the absorbent core is composed of a substrate layer, a functional layer and a wrapping layer, wherein the substrate layer is a mixed fluff fiber of bleached softwood pulp and hardwood pulp (quantity 40-60g / m 2 ), the functional layer is a uniform mixture of polymer water-absorbing resin (SAP) and fluff pulp in a mass ratio of 1: (1.5-2.5), and the wrapping layer is a hydrophilic spunbond nonwoven fabric (unit weight is 18-22g / m 2 During the preparation process, fluff pulp fibers are opened and air-laid to form a substrate layer; SAP particles are then evenly distributed on the substrate surface through a quantitative powder spreading device; finally, the substrate is covered with a wrapping layer and then hot-pressed (110-130°C, 30-50kPa, 2-5s) for shaping.

[0124] In some optional embodiments, the breathable bottom layer is a breathable microporous membrane with a water vapor transmission rate of ≥2000g / m 2 / 24h (38°C, 90% RH), hydrostatic pressure ≥50mbar, micropore diameter of 0.5-5μm, thickness of 15-30μm.

[0125] It should be emphasized again that the bonding methods and operating conditions for each functional layer, as well as the specific parameters and preparation processes of the functional layers described above are merely recommended implementation plans, intended to help understand the completeness of the technical solution. Alternative solutions known in the art are equally applicable. For example, the liquid-permeable surface layer can utilize a perforated PE membrane, spunlace nonwoven fabric, etc., the absorbent core can utilize a composite core (containing fluffy cotton + SAP + a flow-guiding layer) or a full core structure, and the breathable bottom layer can utilize a breathable elastic membrane, nanofiber membrane, etc. As long as the layered structure possesses the basic functions of liquid permeability, absorption, and barrier properties, and can achieve the basic performance of the sanitary napkin when combined with the flow-guiding and antibacterial layer of the present invention, it is an equivalent technical solution of the present invention.

[0126] Compared with the prior art, the present invention has the following beneficial effects:

[0127] The present invention maximizes the protection and release of multiple natural antibacterial active substances through β-cyclodextrin inclusion and liposome coating; significantly improves the hydrophilic flow conduction ability of polypropylene fiber and imparts it with antibacterial properties through chitosan grafting modification; finally, the modified plant fiber and modified polypropylene fiber are blended and hot-pressed to obtain a highly efficient and long-lasting antibacterial layer that can quickly conduct liquid and maintain high breathability. This effectively solves the technical problems of traditional sanitary napkin products such as short-lasting antibacterial effect, slow liquid penetration, and easy breeding of bacteria in hot and humid environments, thereby improving the safety and comfort of sanitary napkins. BRIEF DESCRIPTION OF THE DRAWINGS

[0128] Figure 1 A process flow chart of the method for preparing the plant fiber breathable and antibacterial sanitary napkin provided in Examples 1-15 of the present invention;

[0129] Figure 2 This is a diagram showing the antibacterial effect of the diversion and antibacterial layer prepared in Example 1 of the present invention on Staphylococcus aureus;

[0130] Figure 3 This is a diagram showing the antibacterial effect of the diversion and antibacterial layer prepared in Example 1 of the present invention on Escherichia coli. DETAILED DESCRIPTION

[0131] The technical solutions of the present invention are described in detail below in conjunction with specific embodiments and their accompanying drawings. The embodiments described herein are specific embodiments of the present invention and are used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary and should not be understood as limiting the embodiments of the present invention and the scope of protection of the present invention. In addition to the embodiments described herein, those skilled in the art can also adopt other obvious technical solutions based on the contents disclosed in the claims of this application and its specification, including technical solutions that adopt any obvious replacements and modifications to the embodiments described herein.

[0132] Example 1

[0133] This embodiment provides a method for preparing a breathable and antibacterial plant fiber sanitary napkin. Figure 1 As shown, the preparation method specifically includes the following steps:

[0134] (1) Tea polyphenols and salicylic acid were added to deionized water in a mass ratio of 3.5:1, and stirred and heated at 45°C for 35 minutes to obtain a core material solution, wherein the total mass fraction of tea polyphenols and salicylic acid in the core material solution was 1.5 wt%; β-cyclodextrin was added to the core material solution, and the mass ratio of the total mass of tea polyphenols and salicylic acid to the mass of β-cyclodextrin was 1:3, and stirred and heated at 50°C for 2.5 hours, and then cooled to 4°C and kept warm for 2 hours to form a precipitate, which was filtered and freeze-dried at -40°C for 24 hours to obtain an inclusion compound;

[0135] Lecithin was added to anhydrous ethanol, and the mixture was stirred and heated at 60° C. for 40 minutes to obtain a lecithin solution, wherein the mass fraction of lecithin in the lecithin solution was 18 wt %; chamomile extract was added to PBS buffer (pH=7.2), and the mixture was stirred and heated at 40° C. for 30 minutes to obtain a chamomile extract solution, wherein the mass fraction of chamomile extract in the chamomile extract solution was 8 wt %;

[0136] Under stirring conditions, the chamomile extract solution was dropped into the lecithin solution at a dropping rate of 3 mL / min, the mass ratio of chamomile extract to lecithin was 1:1.5, and after all the dropwise addition, the obtained mixed solution was stirred at a speed of 3000 rpm for 8 minutes to obtain a suspension; the suspension was rotary evaporated at 40° C. for 40 minutes to remove ethanol, and then filtered using an ultrafiltration membrane with a molecular weight cutoff of 10 kDa, the retentate was collected, and trehalose was added to the retentate in an amount of 7wt% of the mass of the retentate, and finally placed at -40° C. and freeze-dried for 24 hours to obtain liposomes;

[0137] The inclusion complex, liposomes, chitosan quaternary ammonium salt and deionized water were mixed to obtain an antibacterial solution, wherein the mass fraction of the inclusion complex, the mass fraction of the liposomes and the mass fraction of the chitosan quaternary ammonium salt were 1.3 wt %, 1 wt % and 0.5 wt % respectively;

[0138] (2) immersing polypropylene fiber in a silane coupling agent solution, wherein the silane coupling agent solution consists of a silane coupling agent KH550 and an ethanol aqueous solution, wherein the mass fraction of the silane coupling agent KH550 in the silane coupling agent solution is 2.5 wt %, and the mass ratio of the polypropylene fiber to the silane coupling agent in the silane coupling agent solution is 100:1.5, heating and shaking at a temperature of 40° C. and a speed of 120 rpm for 3.5 h, and then taking out the fiber for washing and drying to obtain a silane-modified fiber;

[0139] Dissolving chitosan in a 1 wt % acetic acid aqueous solution to obtain a chitosan solution, wherein the mass fraction of chitosan in the chitosan solution is 2.5 wt %, and adding 0.1 M alkali solution dropwise to the chitosan solution to adjust its pH value to 5.2;

[0140] The silane-modified fiber was immersed in a chitosan solution at a ratio of 1 g:20 mL, and immersed at a negative pressure of -0.06 MPa and a rotation speed of 100 rpm for 40 minutes, and then returned to normal pressure. The fiber was taken out and immersed in a 0.5 wt% genipin solution, cross-linked at 50°C for 2.5 hours, and finally filtered, washed and dried to obtain modified polypropylene fiber;

[0141] (3) immersing the bamboo fiber, hemp fiber and kapok fiber in the antibacterial solution obtained in step (1) at a mass ratio of 1:0.4:0.2, immersing at a temperature of 40° C. for 35 minutes, and then taking out and drying to obtain modified plant fibers;

[0142] The modified plant fiber is fed into an opener for opening for 10 minutes at a speed of 3000 rpm, the opened modified plant fiber is mixed with the modified polypropylene fiber obtained in step (2) at a mass ratio of 2:1 to obtain a mixed fiber, and the mixed fiber is dispersed in water to form a fiber suspension, wherein the mass fraction of the mixed fiber in the fiber suspension is 0.4 wt%;

[0143] The fiber suspension was put into a 120 mesh inclined net wet-laid machine and wet-laid at a vacuum degree of -0.03 MPa and a net speed of 15 m / min to obtain a fiber with a basis weight of 45 g / m 2 Spray copolyester hot melt adhesive powder on the surface of the fiber mesh, and the spraying amount of copolyester hot melt adhesive powder is 8g / m 2 The fiber web was then hot-pressed at a temperature of 120°C and a pressure of 40 kPa for 20 seconds to obtain a diversion and antibacterial layer;

[0144] (4) The spunbond nonwoven fabric, the diversion and antibacterial layer obtained in step (3), the absorbent core and the breathable microporous membrane are stacked in sequence and bonded with a point-shaped hot melt adhesive. The amount of hot melt adhesive sprayed is 5g / m 2 ; Subsequently, the edges are heat-pressed and sealed for 3 seconds at a temperature of 120° C. and a pressure of 40 kPa; Finally, a release film is attached to the surface of the breathable bottom layer to obtain the plant fiber breathable and antibacterial sanitary napkin.

[0145] Figure 2 and Figure 3The figures show the antibacterial effects of the diversion and antibacterial layer prepared in Example 1 of the present invention on Staphylococcus aureus and Escherichia coli. It can be seen from the figure that an inhibition zone of a certain width is formed on the periphery of the diversion and antibacterial layer, which indicates that the diversion and antibacterial layer prepared in the present invention has a significant antibacterial effect on Staphylococcus aureus and Escherichia coli.

[0146] Example 2

[0147] This embodiment provides a method for preparing a breathable and antibacterial plant fiber sanitary napkin. Figure 1 As shown, the preparation method specifically includes the following steps:

[0148] (1) Tea polyphenols and salicylic acid were added to deionized water in a mass ratio of 3.8:1, and stirred and heated at 48°C for 32 minutes to obtain a core material solution, wherein the total mass fraction of tea polyphenols and salicylic acid in the core material solution was 1.8 wt%; β-cyclodextrin was added to the core material solution, and the mass ratio of the total mass of tea polyphenols and salicylic acid to the mass of β-cyclodextrin was 1:3.5, and stirred and heated at 52°C for 2.2 hours, and then cooled to 4.5°C and kept warm for 2.2 hours to form a precipitate, which was filtered and freeze-dried at -42°C for 21 hours to obtain an inclusion compound;

[0149] Lecithin was added to anhydrous ethanol, and the mixture was stirred and heated at 62° C. for 38 minutes to obtain a lecithin solution, wherein the mass fraction of lecithin in the lecithin solution was 19 wt %; chamomile extract was added to PBS buffer (pH=7.2), and the mixture was stirred and heated at 42° C. for 28 minutes to obtain a chamomile extract solution, wherein the mass fraction of chamomile extract in the chamomile extract solution was 9 wt %;

[0150] Under stirring conditions, the chamomile extract solution was dropped into the lecithin solution at a dropping rate of 3.5 mL / min, the mass ratio of chamomile extract to lecithin was 1:1.8, and after all the dropwise addition, the obtained mixed solution was stirred at a speed of 3200 rpm for 7 minutes to obtain a suspension; the suspension was rotary evaporated at 42° C. for 38 minutes to remove ethanol, and then filtered using an ultrafiltration membrane with a molecular weight cutoff of 10 kDa, the retentate was collected, and trehalose was added to the retentate in an amount of 7.5 wt% of the mass of the retentate, and finally placed at -42° C. and freeze-dried for 21 hours to obtain liposomes;

[0151] The inclusion complex, liposomes, chitosan quaternary ammonium salt and deionized water were mixed to obtain an antibacterial solution, wherein the mass fraction of the inclusion complex in the antibacterial solution was 1.35wt%, the mass fraction of the liposomes was 1.1wt%, and the mass fraction of the chitosan quaternary ammonium salt was 0.4wt%;

[0152] (2) immersing polypropylene fiber in a silane coupling agent solution, wherein the silane coupling agent solution consists of a silane coupling agent KH550 and an ethanol aqueous solution, wherein the mass fraction of the silane coupling agent KH550 in the silane coupling agent solution is 2.8 wt %, and the mass ratio of the polypropylene fiber to the silane coupling agent in the silane coupling agent solution is 100:1.8, heating and shaking at a temperature of 42° C. and a rotation speed of 130 rpm for 3.2 h, and then taking out the fiber for washing and drying to obtain a silane-modified fiber;

[0153] Dissolving chitosan in a 1.1 wt % acetic acid aqueous solution to obtain a chitosan solution, wherein the mass fraction of chitosan in the chitosan solution is 2.8 wt %, and adding 0.1 M alkali solution dropwise to the chitosan solution to adjust its pH value to 5.3;

[0154] The silane-modified fiber was immersed in a chitosan solution at a ratio of 1 g:22 mL, and immersed at a negative pressure of -0.065 MPa and a rotation speed of 105 rpm for 38 minutes, and then returned to normal pressure. The fiber was taken out and immersed in a 0.55 wt% genipin solution, cross-linked at 52°C for 2.2 hours, and finally filtered, washed and dried to obtain modified polypropylene fiber;

[0155] (3) immersing the bamboo fiber, hemp fiber, and kapok fiber in the antibacterial solution obtained in step (1) at a mass ratio of 1:0.42:0.22, immersing at a temperature of 42° C. for 32 minutes, and then taking out and drying to obtain modified plant fibers;

[0156] The modified plant fiber was fed into an opener for opening for 11 minutes at a speed of 2800 rpm, the opened modified plant fiber was mixed with the modified polypropylene fiber obtained in step (2) at a mass ratio of 2.2:1 to obtain a mixed fiber, and the mixed fiber was dispersed in water to form a fiber suspension, wherein the mass fraction of the mixed fiber in the fiber suspension was 0.45 wt%;

[0157] The fiber suspension was put into a 130 mesh inclined net wet-laid machine and wet-laid at a vacuum degree of -0.032 MPa and a net speed of 18 m / min to obtain a fiber with a basis weight of 48 g / m 2 Spray copolyester hot melt adhesive powder on the surface of the fiber web, and the spraying amount of copolyester hot melt adhesive powder is 9g / m 2 The fiber web was then hot pressed at a temperature of 122°C and a pressure of 38 kPa for 22 seconds to obtain a diversion and antibacterial layer;

[0158] (4) The spunbond nonwoven fabric, the diversion and antibacterial layer obtained in step (3), the absorbent core and the breathable microporous membrane are stacked in sequence and bonded with a point-shaped hot melt adhesive. The amount of hot melt adhesive sprayed is 5.5 g / m 2; Subsequently, the edges were heat-pressed and sealed for 3.5 seconds at a temperature of 122° C. and a pressure of 38 kPa; Finally, a release film was attached to the surface of the breathable bottom layer to obtain the plant fiber breathable and antibacterial sanitary napkin.

[0159] Example 3

[0160] This embodiment provides a method for preparing a breathable and antibacterial plant fiber sanitary napkin. Figure 1 As shown, the preparation method specifically includes the following steps:

[0161] (1) Tea polyphenols and salicylic acid were added to deionized water in a mass ratio of 4:1, and stirred and heated at 50°C for 30 minutes to obtain a core material solution, wherein the total mass fraction of tea polyphenols and salicylic acid in the core material solution was 2 wt%; β-cyclodextrin was added to the core material solution, and the mass ratio of the total mass of tea polyphenols and salicylic acid to the mass of β-cyclodextrin was 1:4, and stirred and heated at 55°C for 2 hours, and then cooled to 5°C and kept warm for 2.5 hours to form a precipitate, and after filtering, the precipitate was freeze-dried at -45°C for 18 hours to obtain an inclusion compound;

[0162] Lecithin was added to anhydrous ethanol, and the mixture was stirred and heated at 65° C. for 35 minutes to obtain a lecithin solution, wherein the mass fraction of lecithin in the lecithin solution was 20 wt %; chamomile extract was added to PBS buffer (pH=7.2), and the mixture was stirred and heated at 45° C. for 25 minutes to obtain a chamomile extract solution, wherein the mass fraction of chamomile extract in the chamomile extract solution was 10 wt %;

[0163] Under stirring conditions, the chamomile extract solution was dropped into the lecithin solution at a dropping rate of 4 mL / min, the mass ratio of chamomile extract to lecithin was 1:2, and after all the dropwise addition, the obtained mixed solution was stirred at a speed of 3500 rpm for 6 minutes to obtain a suspension; the suspension was rotary evaporated at 45° C. for 35 minutes to remove ethanol, and then filtered using an ultrafiltration membrane with a molecular weight cutoff of 10 kDa, the retentate was collected, and trehalose was added to the retentate, the amount of trehalose added was 8wt% of the mass of the retentate, and finally placed at -45° C. and freeze-dried for 18 hours to obtain liposomes;

[0164] The inclusion complex, liposomes, chitosan quaternary ammonium salt and deionized water were mixed to obtain an antibacterial solution, wherein the mass fraction of the inclusion complex in the antibacterial solution was 1.4 wt %, the mass fraction of the liposomes was 0.9 wt % and the mass fraction of the chitosan quaternary ammonium salt was 0.5 wt %;

[0165] (2) immersing polypropylene fiber in a silane coupling agent solution, wherein the silane coupling agent solution consists of a silane coupling agent KH550 and an ethanol aqueous solution, wherein the mass fraction of the silane coupling agent KH550 in the silane coupling agent solution is 3 wt %, and the mass ratio of the polypropylene fiber to the silane coupling agent in the silane coupling agent solution is 100:2, heating and shaking at a temperature of 45° C. and a speed of 130 rpm for 3 h, and then taking out the fiber for washing and drying to obtain a silane-modified fiber;

[0166] Dissolving chitosan in a 1.2 wt % acetic acid aqueous solution to obtain a chitosan solution, wherein the mass fraction of chitosan in the chitosan solution is 3 wt %, and adding 0.1 M alkali solution dropwise to the chitosan solution to adjust its pH value to 5.4;

[0167] The silane-modified fiber was immersed in a chitosan solution at a ratio of 1 g:25 mL, and immersed at a negative pressure of -0.07 MPa and a rotation speed of 110 rpm for 35 minutes, and then returned to normal pressure. The fiber was taken out and immersed in a 0.6 wt% genipin solution, cross-linked at 55 ° C for 2 hours, and finally filtered, washed and dried to obtain modified polypropylene fiber;

[0168] (3) immersing the bamboo fiber, hemp fiber and kapok fiber in the antibacterial solution obtained in step (1) at a mass ratio of 1:0.45:0.25, immersing at a temperature of 45° C. for 30 minutes, and then taking out and drying to obtain modified plant fibers;

[0169] The modified plant fiber is fed into an opener for opening for 12 minutes at a rotation speed of 2700 rpm, the opened modified plant fiber is mixed with the modified polypropylene fiber obtained in step (2) at a mass ratio of 2.5:1 to obtain a mixed fiber, and the mixed fiber is dispersed in water to form a fiber suspension, wherein the mass fraction of the mixed fiber in the fiber suspension is 0.5 wt%;

[0170] The fiber suspension was put into a 130 mesh inclined net wet-laid machine and wet-laid at a vacuum degree of -0.035 MPa and a net speed of 20 m / min to obtain a fiber with a basis weight of 50 g / m 2 Spray copolyester hot melt adhesive powder on the surface of the fiber mesh, and the spraying amount of copolyester hot melt adhesive powder is 10g / m 2 The fiber web was then hot-pressed at a temperature of 125°C and a pressure of 35 kPa for 25 seconds to obtain a diversion and antibacterial layer;

[0171] (4) The spunbond nonwoven fabric, the diversion and antibacterial layer obtained in step (3), the absorbent core and the breathable microporous membrane are stacked in sequence and bonded with a point-shaped hot melt adhesive. The amount of hot melt adhesive sprayed is 6 g / m 2; Subsequently, the edges are heat-pressed and sealed at a temperature of 125° C. and a pressure of 35 kPa for 4 seconds; finally, a release film is attached to the surface of the breathable bottom layer to obtain the plant fiber breathable and antibacterial sanitary napkin.

[0172] Example 4

[0173] This embodiment provides a method for preparing a breathable and antibacterial plant fiber sanitary napkin. Figure 1 As shown, the preparation method specifically includes the following steps:

[0174] (1) Tea polyphenols and salicylic acid were added to deionized water in a mass ratio of 4.2:1, and stirred and heated at 52°C for 28 minutes to obtain a core material solution, wherein the total mass fraction of tea polyphenols and salicylic acid in the core material solution was 2.2 wt%; β-cyclodextrin was added to the core material solution, and the mass ratio of the total mass of tea polyphenols and salicylic acid to the mass of β-cyclodextrin was 1:4.5, and stirred and heated at 58°C for 1.8 hours, and then cooled to 5.5°C and kept warm for 2.8 hours to form a precipitate, which was filtered and freeze-dried at -48°C for 15 hours to obtain an inclusion compound;

[0175] Lecithin was added to anhydrous ethanol, and the mixture was stirred and heated at 68° C. for 32 minutes to obtain a lecithin solution, wherein the mass fraction of lecithin in the lecithin solution was 21 wt %; chamomile extract was added to PBS buffer (pH=7.2), and the mixture was stirred and heated at 48° C. for 22 minutes to obtain a chamomile extract solution, wherein the mass fraction of chamomile extract in the chamomile extract solution was 11 wt %;

[0176] Under stirring conditions, the chamomile extract solution was dropped into the lecithin solution at a dropping rate of 4.5 mL / min, the mass ratio of chamomile extract to lecithin was 1:2.2, and after all the dropwise addition, the obtained mixed solution was stirred at a speed of 3800 rpm for 6 min to obtain a suspension; the suspension was rotary evaporated at 48 ° C for 32 min to remove ethanol, and then filtered using an ultrafiltration membrane with a molecular weight cutoff of 10 kDa, the retentate was collected, and trehalose was added to the retentate, the amount of trehalose added was 8.5 wt% of the mass of the retentate, and finally placed at -48 ° C for lyophilization for 15 h to obtain liposomes;

[0177] The inclusion complex, liposomes, chitosan quaternary ammonium salt and deionized water were mixed to obtain an antibacterial solution, wherein the mass fraction of the inclusion complex in the antibacterial solution was 1.45wt%, the mass fraction of the liposomes was 0.8wt%, and the mass fraction of the chitosan quaternary ammonium salt was 0.6wt%;

[0178] (2) immersing polypropylene fiber in a silane coupling agent solution, wherein the silane coupling agent solution consists of a silane coupling agent KH550 and an ethanol aqueous solution, wherein the mass fraction of the silane coupling agent KH550 in the silane coupling agent solution is 3.2 wt %, and the mass ratio of the polypropylene fiber to the silane coupling agent in the silane coupling agent solution is 100:2.2, heating and shaking at a temperature of 48° C. and a rotation speed of 140 rpm for 2.8 h, and then taking out the fiber for washing and drying to obtain a silane-modified fiber;

[0179] Dissolving chitosan in a 1.3 wt % acetic acid aqueous solution to obtain a chitosan solution, wherein the mass fraction of chitosan in the chitosan solution is 3.2 wt %, and adding 0.1 M alkali solution dropwise to the chitosan solution to adjust its pH value to 5.5;

[0180] The silane-modified fiber was immersed in a chitosan solution at a ratio of 1 g:28 mL, and immersed at a negative pressure of -0.075 MPa and a rotation speed of 115 rpm for 32 minutes, and then returned to normal pressure. The fiber was taken out and immersed in a 0.65 wt% genipin solution, cross-linked at 58 ° C for 1.8 hours, and finally filtered, washed and dried to obtain modified polypropylene fiber;

[0181] (3) immersing the bamboo fiber, hemp fiber and kapok fiber in the antibacterial solution obtained in step (1) at a mass ratio of 1:0.48:0.28, immersing at a temperature of 48° C. for 28 minutes, and then taking out and drying to obtain modified plant fiber;

[0182] The modified plant fiber was fed into an opener for opening for 13 minutes at a speed of 2600 rpm, the opened modified plant fiber was mixed with the modified polypropylene fiber obtained in step (2) at a mass ratio of 2.8:1 to obtain a mixed fiber, and the mixed fiber was dispersed in water to form a fiber suspension, wherein the mass fraction of the mixed fiber in the fiber suspension was 0.55 wt %;

[0183] The fiber suspension was put into a 140 mesh inclined net wet-laid machine and wet-laid at a vacuum degree of -0.038 MPa and a net speed of 22 m / min to obtain a fiber with a basis weight of 52 g / m 2 Spray copolyester hot melt adhesive powder on the surface of the fiber mesh, and the spraying amount of copolyester hot melt adhesive powder is 11g / m 2 The fiber web was then hot pressed at a temperature of 128°C and a pressure of 32 kPa for 28 seconds to obtain a diversion and antibacterial layer;

[0184] (4) The spunbond nonwoven fabric, the diversion and antibacterial layer obtained in step (3), the absorbent core and the breathable microporous membrane are stacked in sequence and bonded with a point-shaped hot melt adhesive. The amount of hot melt adhesive sprayed is 6.5 g / m 2; Subsequently, the edges were heat-pressed and sealed at a temperature of 128° C. and a pressure of 32 kPa for 4.5 seconds; finally, a release film was attached to the surface of the breathable bottom layer to obtain the plant fiber breathable and antibacterial sanitary napkin.

[0185] Example 5

[0186] This embodiment provides a method for preparing a breathable and antibacterial plant fiber sanitary napkin. Figure 1 As shown, the preparation method specifically includes the following steps:

[0187] (1) Tea polyphenols and salicylic acid were added to deionized water in a mass ratio of 4.5:1, and stirred and heated at 55°C for 25 minutes to obtain a core material solution, wherein the total mass fraction of tea polyphenols and salicylic acid in the core material solution was 2.5 wt%; β-cyclodextrin was added to the core material solution, and the mass ratio of the total mass of tea polyphenols and salicylic acid to the mass of β-cyclodextrin was 1:5, and stirred and heated at 60°C for 1.5 hours, and then cooled to 6°C and kept warm for 3 hours to form a precipitate, which was filtered and freeze-dried at -50°C for 12 hours to obtain an inclusion compound;

[0188] Lecithin was added to anhydrous ethanol, and the mixture was stirred and heated at 70° C. for 30 minutes to obtain a lecithin solution, wherein the mass fraction of lecithin in the lecithin solution was 22 wt %; chamomile extract was added to PBS buffer (pH=7.2), and the mixture was stirred and heated at 50° C. for 20 minutes to obtain a chamomile extract solution, wherein the mass fraction of chamomile extract in the chamomile extract solution was 12 wt %;

[0189] Under stirring conditions, the chamomile extract solution was dropped into the lecithin solution at a dropping rate of 5 mL / min, the mass ratio of chamomile extract to lecithin was 1:2.5, and after all the dropwise addition, the obtained mixed solution was stirred at a speed of 4000 rpm for 5 minutes to obtain a suspension; the suspension was rotary evaporated at 50° C. for 30 minutes to remove ethanol, and then filtered using an ultrafiltration membrane with a molecular weight cutoff of 10 kDa, the retentate was collected, and trehalose was added to the retentate, the amount of trehalose added was 9wt% of the mass of the retentate, and finally placed at -50° C. and freeze-dried for 12 hours to obtain liposomes;

[0190] The inclusion complex, liposomes, chitosan quaternary ammonium salt and deionized water were mixed to obtain an antibacterial solution, wherein the mass fraction of the inclusion complex in the antibacterial solution was 1.5wt%, the mass fraction of the liposomes was 0.9wt%, and the mass fraction of the chitosan quaternary ammonium salt was 0.4wt%;

[0191] (2) immersing polypropylene fiber in a silane coupling agent solution, wherein the silane coupling agent solution consists of a silane coupling agent KH550 and an ethanol aqueous solution, wherein the mass fraction of the silane coupling agent KH550 in the silane coupling agent solution is 3.5 wt %, and the mass ratio of the polypropylene fiber to the silane coupling agent in the silane coupling agent solution is 100:2.5, heating and shaking at a temperature of 50° C. and a speed of 150 rpm for 2.5 h, and then taking out the fiber for washing and drying to obtain a silane-modified fiber;

[0192] Dissolving chitosan in a 1.5 wt % acetic acid aqueous solution to obtain a chitosan solution, wherein the mass fraction of chitosan in the chitosan solution is 3.5 wt %, and adding 0.1 M alkali solution dropwise to the chitosan solution to adjust its pH value to 5.6;

[0193] The silane-modified fiber was immersed in a chitosan solution at a ratio of 1 g:30 mL, and immersed at a negative pressure of -0.08 MPa and a rotation speed of 120 rpm for 30 min, and then returned to normal pressure. The fiber was taken out and immersed in a 0.7 wt% genipin solution, cross-linked at 60°C for 1.5 h, and finally filtered, washed and dried to obtain a modified polypropylene fiber;

[0194] (3) immersing the bamboo fiber, hemp fiber and kapok fiber in the antibacterial solution obtained in step (1) at a mass ratio of 1:0.5:0.3, immersing at a temperature of 50° C. for 25 minutes, and then taking out and drying to obtain modified plant fibers;

[0195] The modified plant fiber is fed into an opener for opening for 15 minutes at a speed of 2500 rpm, the opened modified plant fiber is mixed with the modified polypropylene fiber obtained in step (2) at a mass ratio of 3:1 to obtain a mixed fiber, and the mixed fiber is dispersed in water to form a fiber suspension, wherein the mass fraction of the mixed fiber in the fiber suspension is 0.6 wt%;

[0196] The fiber suspension was put into a 150 mesh inclined net wet-laid machine and wet-laid at a vacuum degree of -0.04 MPa and a net speed of 25 m / min to obtain a fiber with a basis weight of 55 g / m 2 Spray copolyester hot melt adhesive powder on the surface of the fiber mesh, and the spraying amount of copolyester hot melt adhesive powder is 12g / m 2 The fiber web was then hot-pressed at a temperature of 130°C and a pressure of 30 kPa for 30 seconds to obtain a diversion and antibacterial layer;

[0197] (4) The spunbond nonwoven fabric, the diversion and antibacterial layer obtained in step (3), the absorbent core and the breathable microporous membrane are stacked in sequence and bonded with a point-shaped hot melt adhesive. The amount of hot melt adhesive sprayed is 7 g / m 2; Subsequently, the edges are heat-pressed and sealed at a temperature of 130° C. and a pressure of 30 kPa for 5 seconds; finally, a release film is attached to the surface of the breathable bottom layer to obtain the plant fiber breathable and antibacterial sanitary napkin.

[0198] Example 6

[0199] This embodiment provides a method for preparing a breathable and antibacterial plant fiber sanitary napkin. The difference from Example 1 is that in step (1), the mass ratio of tea polyphenols to salicylic acid is adjusted to 3:1, and the other process parameters and operating steps are exactly the same as those in Example 1.

[0200] Example 7

[0201] This embodiment provides a method for preparing a breathable and antibacterial plant fiber sanitary napkin. The difference from Example 1 is that in step (1), the mass ratio of tea polyphenols to salicylic acid is adjusted to 5:1, and the other process parameters and operating steps are exactly the same as those in Example 1.

[0202] Example 8

[0203] This embodiment provides a method for preparing a breathable and antibacterial plant fiber sanitary napkin. The difference from Example 1 is that in step (1), the ratio of the total mass of tea polyphenols and salicylic acid in the core material solution to the mass of β-cyclodextrin is adjusted to 1:2, and the other process parameters and operating steps are exactly the same as those in Example 1.

[0204] Example 9

[0205] This embodiment provides a method for preparing a breathable and antibacterial plant fiber sanitary napkin. The difference from Example 1 is that in step (1), the ratio of the total mass of tea polyphenols and salicylic acid in the core material solution to the mass of β-cyclodextrin is adjusted to 1:6, and the other process parameters and operating steps are exactly the same as those in Example 1.

[0206] Example 10

[0207] This embodiment provides a method for preparing a breathable and antibacterial plant fiber sanitary napkin. The difference from Example 1 is that in step (1), the mass ratio of chamomile extract in the chamomile extract solution to lecithin in the lecithin solution is adjusted to 1:1, and the other process parameters and operating steps are exactly the same as those in Example 1.

[0208] Example 11

[0209] This embodiment provides a method for preparing a breathable and antibacterial plant fiber sanitary napkin. The difference from Example 1 is that in step (1), the mass ratio of chamomile extract in the chamomile extract solution to lecithin in the lecithin solution is adjusted to 1:3, and the other process parameters and operating steps are exactly the same as those in Example 1.

[0210] Example 12

[0211] This embodiment provides a method for preparing a breathable and antibacterial plant fiber sanitary napkin. The difference from Example 1 is that in step (2), the mass fraction of chitosan in the chitosan solution is adjusted to 2 wt %. The other process parameters and operating steps are exactly the same as those in Example 1.

[0212] Example 13

[0213] This embodiment provides a method for preparing a breathable and antibacterial plant fiber sanitary napkin. The difference from Example 1 is that in step (2), the mass fraction of chitosan in the chitosan solution is adjusted to 4 wt %. The other process parameters and operating steps are exactly the same as those in Example 1.

[0214] Example 14

[0215] This embodiment provides a method for preparing a breathable and antibacterial plant fiber sanitary napkin. The difference from Example 1 is that in step (3), the mass ratio of the modified plant fiber to the modified polypropylene fiber is adjusted to 1:1, and the other process parameters and operating steps are exactly the same as those in Example 1.

[0216] Example 15

[0217] This embodiment provides a method for preparing a breathable and antibacterial plant fiber sanitary napkin. The difference from Example 1 is that in step (3), the mass ratio of the modified plant fiber to the modified polypropylene fiber is adjusted to 4:1, and the other process parameters and operating steps are exactly the same as those in Example 1.

[0218] Comparative Example 1

[0219] This comparative example provides a method for preparing a breathable and antibacterial sanitary napkin made of plant fiber. The method differs from Example 1 in that tea polyphenols and salicylic acid are not co-included with β-cyclodextrin, the antibacterial solution consists of tea polyphenols, salicylic acid, liposomes, chitosan quaternary ammonium salt and deionized water, the mass fraction of tea polyphenols and salicylic acid in the antibacterial solution is 1.3wt%, the mass ratio of tea polyphenols to salicylic acid is 3.5:1, and the other process parameters and operating steps are exactly the same as those in Example 1.

[0220] Comparative Example 2

[0221] This comparative example provides a method for preparing a breathable and antibacterial sanitary napkin made of plant fiber. The method differs from Example 1 in that the chamomile extract is not coated with lecithin, the antibacterial solution consists of an inclusion complex, chamomile extract, chitosan quaternary ammonium salt and deionized water, the mass fraction of the chamomile extract in the antibacterial solution is 1 wt %, and the other process parameters and operating steps are exactly the same as those in Example 1.

[0222] Comparative Example 3

[0223] This comparative example provides a method for preparing a breathable and antibacterial sanitary napkin made of plant fibers. The difference from comparative example 1 is that in step (3), the plant fibers are not modified, and the plant fibers (the mass ratio of bamboo fiber, hemp fiber and kapok fiber is 1:0.4:0.2) are blended and hot-pressed with modified polypropylene fibers to obtain a diversion and antibacterial layer. The other process parameters and operating steps are exactly the same as those in Example 1.

[0224] Comparative Example 4

[0225] This comparative example provides a method for preparing a breathable and antibacterial sanitary napkin made of plant fibers. The difference from comparative example 1 is that step (2) is omitted and the polypropylene fiber is not modified. In step (3), the modified plant fiber and the unmodified polypropylene fiber are blended and hot-pressed to obtain a diversion and antibacterial layer. The other process parameters and operating steps are exactly the same as those in Example 1.

[0226] The antibacterial rate, air permeability and moisture permeability of the diversion and antibacterial layers prepared in Examples 1-15 and Comparative Examples 1-4 were tested. The specific testing steps are as follows:

[0227] (1) Antibacterial rate

[0228] Staphylococcus aureus (ATCC 6538) and Escherichia coli (ATCC 25922) were inoculated into nutrient broth, cultured at 37°C for 24 h, and then centrifuged at 3000 rpm for 10 min. The cells were collected, washed three times with PBS, and diluted to a concentration of 1×10 5 CFU / mL;

[0229] Take the diversion and antibacterial layers prepared in the examples and comparative examples, cut them into 5×5 mm pieces, weigh 0.5 g, sterilize them with high pressure steam at 121° C. for 20 min, and dry them at 60° C. for later use;

[0230] The sterilized sample was placed in a 50 mL sterile conical flask, and 0.5 mL of artificial menstrual fluid (phosphate buffered saline (PBS) + 5% fetal bovine serum + 0.9% NaCl + 1% sodium carboxymethyl cellulose) and 0.1 mL of bacterial solution (final concentration ≈ 10 4 CFU / mL), and cultured at 37°C and 150 rpm for 24 h to obtain the bacterial solution of the experimental group;

[0231] 0.5 mL of artificial menstrual fluid and 0.1 mL of bacterial solution were mixed and cultured at 37°C and 150 rpm for 24 h to obtain the blank bacterial solution;

[0232] Take 100 μL of the bacterial solution of the experimental group and the blank group, dilute them with PBS (10-1 ~10 -6 ), spread on nutrient agar plates, culture at 37 °C for 24 h, and count colony forming units (CFU).

[0233] The inhibition rate was calculated using the following formula:

[0234] Inhibition rate (%) = [(AB) / A] × 100%;

[0235] Among them, A is the CFU of the blank group, and B is the CFU of the experimental group.

[0236] (2) Air permeability

[0237] According to the national standard GB / T 5453-1997 "Determination of Air Permeability of Textile Fabrics", a fabric air permeability meter was used to test the average air flow of the diversion and antibacterial layer under a pressure difference of 100 Pa, and the air permeability was calculated.

[0238] (3) Moisture permeability

[0239] According to the national standard GB / T 12704.2-2009 "Test method for water vapor permeability of textile fabrics - Part 2: Evaporation method", use a moisture permeability cup to test the mass of water vapor passing through the antibacterial layer per unit area within 24 hours at 38°C and 90% RH, and calculate the water vapor permeability.

[0240] The test data is shown in Table 1.

[0241] Table 1 Test data of diversion and antibacterial layer

[0242]

[0243]

[0244] The test data from Examples 1, 6, and 7 show that when the tea polyphenol dosage is too low (Example 6), its ability to disrupt bacterial cell membranes is insufficient, resulting in salicylic acid being unable to effectively penetrate the interior of the bacteria and interfere with metabolism. When the tea polyphenol dosage is too high (Example 7), the excess molecules competitively adsorb on the bacterial surface, hindering the effectiveness of other antibacterial ingredients (such as chitosan quaternary ammonium salt). At the same time, the exposed tea polyphenols are more susceptible to oxidation and inactivation during processing.

[0245] From the test data of Examples 1, 8, and 9, it can be seen that when the dosage of β-cyclodextrin is too low (Example 8), some tea polyphenols and salicylic acid are not effectively coated, and a large amount of loss occurs during the hot pressing process due to heat sensitivity and volatility, and continued degradation occurs during storage. When the dosage of β-cyclodextrin is too high (Example 9), a large number of empty molecules occupy the fiber pores, which not only dilutes the effective antibacterial concentration, but also prematurely absorbs water when in contact with liquid, interfering with the normal dissociation and sustained release function of the inclusion complex. In addition, the excess β-cyclodextrin hinders the close bonding of the modified plant fiber and the polypropylene fiber, weakens the structural integrity of the diversion and antibacterial layer, and thus affects its air and moisture permeability.

[0246] The test data from Examples 1, 10, and 11 show that when the lecithin dosage is too low (Example 10), the phospholipid bilayer cannot completely encapsulate the heat-sensitive components, resulting in volatilization and degradation of the chamomile extract during rotary evaporation and hot pressing. When the lecithin dosage is too high (Example 11), the thick phospholipid layer formed will hinder the release rate of the active ingredient, preventing the soothing and antibacterial ingredients from timely penetrating to the site of action. In addition, high lecithin concentrations easily induce liposome aggregation, and the increased particle size makes it difficult to fully penetrate the nano-pores of plant fibers, resulting in uneven distribution of the active ingredient and further reducing the antibacterial efficiency.

[0247] It can be seen from the test data of Examples 1, 12, and 13 that when the concentration of the chitosan solution is too low (Example 12), the chitosan molecules cannot fully cover the silane-activated fiber surface, and the insufficient number of free amino groups leads to a decrease in the degree of crosslinking, making the modified layer easy to peel off during subsequent hot pressing. When the concentration of the chitosan solution is too high (Example 13), the chitosan molecular chains entangle, hindering the diffusion of the genipin crosslinker, forming a loose and easily detachable gel accumulation layer, which not only reduces the hydrophilic flow conductivity of the polypropylene fiber, but also the detached chitosan will clog the pores of the flow-guiding and antibacterial layer, significantly weakening the moisture permeability.

[0248] From the test data of Examples 1, 14, and 15, it can be seen that when the amount of modified plant fiber is too low (Example 14), the total load of the antibacterial active ingredient is insufficient, and there is a lack of a natural porous structure to assist liquid infiltration. When the amount of modified plant fiber is too high (Example 15), the rigid support of the diversion and antibacterial layer is insufficient, and irreversible structural collapse occurs during the hot pressing process. The compressed pores seriously hinder air circulation and water vapor diffusion, and the collapsed structure forms a local hot and humid microenvironment, exacerbating bacterial growth.

[0249] It can be seen from the test data of Example 1 and Comparative Example 1 that Comparative Example 1 does not use β-cyclodextrin inclusion, and tea polyphenols and salicylic acid are directly exposed to a high temperature and high pressure environment. Tea polyphenols are inactivated by oxidative polymerization during hot pressing, and salicylic acid is continuously lost during processing and storage due to molecular volatility, resulting in a sudden drop in the effective antibacterial concentration. In addition, the unincluded tea polyphenols and salicylic acid will also dissolve rapidly under liquid impact, losing the sustained-release function, ultimately resulting in short-term antibacterial effect in the initial stage and failure of antibacterial effect in the later stage.

[0250] It can be seen from the test data of Example 1 and Comparative Example 2 that Comparative Example 2 does not use lecithin coating, and the heat-sensitive essential oil components in the chamomile extract are largely decomposed during the rotary evaporation and hot pressing steps. The unprotected active ingredients directly contact the fiber surface and are partially physically adsorbed by the fiber pores, but the binding force is weak and they are quickly lost under liquid flushing. In addition, the lack of the sustained-release effect of liposomes results in a one-time release of the chamomile extract, which cannot achieve a long-term soothing and care effect.

[0251] It can be seen from the test data of Example 1 and Comparative Example 3 that the plant fiber in Comparative Example 3 was not modified, and the plant fiber without antibacterial active ingredients retained only basic hygroscopicity and completely lost the antibacterial effect, resulting in a significant reduction in the antibacterial efficiency of the diversion antibacterial layer.

[0252] It can be seen from the test data of Example 1 and Comparative Example 4 that the polypropylene fiber in Comparative Example 4 was not modified, and the unmodified polypropylene fiber still retained strong hydrophobicity, forming a local hydrophobic barrier in the diversion and antibacterial layer, which seriously hindered the lateral diffusion of the liquid and the penetration into the absorbent core. When the liquid contacted the diversion and antibacterial layer, the hydrophobic area hindered the uniform distribution of the antibacterial active ingredients, making it impossible for the antibacterial active ingredients to effectively cover the action site, and the antibacterial efficiency was greatly reduced.

[0253] The applicant declares that the above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the scope of protection and disclosure of the present invention.

Claims

1. A plant fiber breathable antibacterial sanitary napkin, characterized in that: The plant fiber breathable and antibacterial sanitary napkin comprises a liquid permeable surface layer, a diversion and antibacterial layer, an absorbent core, a breathable bottom layer and a release film which are sequentially laminated and bonded; The diversion and antibacterial layer is obtained by blending modified plant fibers and modified polypropylene fibers and hot pressing them; The modified plant fiber is obtained by immersing the plant fiber in an antibacterial solution, wherein the antibacterial solution comprises tea polyphenols and salicylic acid co-enclosed by β-cyclodextrin, chamomile extract coated by lecithin, and chitosan quaternary ammonium salt; The modified polypropylene fiber is obtained by sequentially modifying polypropylene fiber with a silane coupling agent and then grafting with chitosan.

2. A method for preparing the plant fiber breathable antibacterial sanitary napkin according to claim 1, characterized in that: The preparation method comprises: (I) tea polyphenols and salicylic acid are included in an inclusion complex using β-cyclodextrin, chamomile extract is coated with lecithin to obtain liposomes, and the inclusion complex, liposomes, chitosan quaternary ammonium salt and deionized water are mixed to obtain an antibacterial solution; (II) modifying polypropylene fibers with a silane coupling agent, immersing the modified polypropylene fibers in a chitosan solution, and adding a crosslinking agent for crosslinking to obtain modified polypropylene fibers; (III) immersing the plant fiber in the antibacterial solution obtained in step (I), taking out and drying to obtain a modified plant fiber, and blending the modified plant fiber with modified polypropylene fiber and hot pressing to obtain a diversion and antibacterial layer; (IV) The liquid-permeable surface layer, the diversion and antibacterial layer, the absorbent core and the breathable bottom layer are sequentially stacked and bonded, and a release film is attached to the surface of the breathable bottom layer to obtain the plant fiber breathable and antibacterial sanitary napkin.

3. The preparation method according to claim 2, characterized in that In step (I), the inclusion compound is prepared by the following method: adding tea polyphenols and salicylic acid to deionized water, stirring and heating to obtain a core material solution; adding β-cyclodextrin to the core material solution, stirring and heating, then cooling to a precipitation temperature and keeping the temperature to form a precipitate, filtering and freeze-drying the precipitate to obtain the inclusion compound; The mass ratio of tea polyphenols to salicylic acid is (3.5-4.5):1; The temperature of stirring and heating the tea polyphenols, salicylic acid and deionized water is 45-55° C.; The stirring and heating time of the tea polyphenols, salicylic acid and deionized water is 25 to 35 minutes; The total mass fraction of tea polyphenols and salicylic acid in the core material solution is 1.5-2.5wt%; The ratio of the total mass of tea polyphenols and salicylic acid in the core material solution to the mass of β-cyclodextrin is 1:(3-5); The temperature of stirring and heating the core material solution and β-cyclodextrin is 50-60°C; The stirring and heating time of the core material solution and β-cyclodextrin is 1.5 to 2.5 hours; The precipitation temperature is 4-6°C; Keep at precipitation temperature for 2 to 3 hours.

4. The preparation method according to claim 2, characterized in that In step (I), the liposomes are prepared by the following method: adding lecithin to anhydrous ethanol, stirring and heating to obtain a lecithin solution; adding chamomile extract to PBS buffer, stirring and heating to obtain a chamomile extract solution; while stirring, dripping the chamomile extract solution into the lecithin solution, and after all the chamomile extract solution is dripped in, stirring the obtained mixed solution at a high speed to obtain a suspension; The suspension is subjected to rotary evaporation to remove ethanol, and then ultrafiltration is performed, and the retentate is collected and freeze-dried to obtain the liposome.

5. The preparation method according to claim 4, characterized in that The temperature of stirring and heating the lecithin and anhydrous ethanol is 60-70° C.; The mass fraction of lecithin in the lecithin solution is 18 to 22 wt %; The temperature of stirring and heating the chamomile extract and PBS buffer solution is 40-50° C.; The mass fraction of the chamomile extract in the chamomile extract solution is 8 to 12 wt %; The mass ratio of the chamomile extract in the chamomile extract solution to the lecithin in the lecithin solution is 1:(1.5-2.5); The chamomile extract solution is added at a rate of 3 to 5 mL / min; The rotation speed of the high-speed stirring is 3000-4000 rpm; The high-speed stirring time is 5 to 8 minutes; The temperature of the rotary evaporation of the suspension is 40-50°C; The time for rotary evaporation of the suspension is 30 to 40 minutes; The ultrafiltration membrane used in the ultrafiltration has a molecular weight cut-off of 10 kDa; Trehalose is added to the retentate, wherein the amount of the trehalose added is 7-9 wt % of the mass of the retentate.

6. The preparation method according to claim 2, characterized in that In step (I), the mass fraction of the inclusion compound in the antibacterial solution is 1.3 to 1.5 wt %; The mass fraction of the liposomes in the antibacterial solution is 0.8 to 1.2 wt %; The mass fraction of the chitosan quaternary ammonium salt in the antibacterial solution is 0.4-0.6 wt %.

7. The preparation method according to claim 2, characterized in that Step (II), the operation steps of modifying the polypropylene fiber with a silane coupling agent include: The polypropylene fiber is immersed in a silane coupling agent solution, heated and shaken, and then the fiber is taken out, washed, and dried to obtain a silane-modified fiber; The mass fraction of the silane coupling agent in the silane coupling agent solution is 2.5 to 3.5 wt %; The mass ratio of the polypropylene fiber to the silane coupling agent in the silane coupling agent solution is 100:(1.5-2.5); The heating temperature of the heating and oscillation of the polypropylene fiber and the silane coupling agent solution is 40 to 50° C. The heating time of the heating oscillation of the polypropylene fiber and the silane coupling agent solution is 2.5 to 3.5 hours; The oscillation speed of the heating oscillation of the polypropylene fiber and the silane coupling agent solution is 120-150 rpm.

8. The preparation method according to claim 2, characterized in that Step (II), the preparation method of the modified polypropylene fiber comprises: Dissolving chitosan in an acetic acid aqueous solution to obtain a chitosan solution, and adding an alkali solution dropwise to the chitosan solution to adjust the pH value thereof; immersing a silane-modified fiber in the chitosan solution, and immersing the fiber in a negative pressure environment and oscillation for a period of time, and then returning the fiber to normal pressure, taking the fiber out, and immersing the fiber in a genipin solution for heating and cross-linking; and finally filtering, washing, and drying the fiber to obtain the modified polypropylene fiber. The mass fraction of the acetic acid aqueous solution is 1 to 1.5 wt%; The mass fraction of chitosan in the chitosan solution is 2.5 to 3.5 wt %; Add 0.1 M alkali solution dropwise to the chitosan solution to adjust its pH value to 5.2-5.6; The ratio of the silane-modified fiber to the chitosan solution is 1 g: (20-30) mL; The vacuum degree of the negative pressure environment is -0.06 to -0.08 MPa; The oscillation speed is 100-120 rpm; The silane-modified fiber is immersed in the chitosan solution for 30 to 40 minutes; The mass fraction of the genipin solution is 0.5-0.7 wt %; The heating cross-linking temperature is 50-60°C; The heating cross-linking time is 1.5 to 2.5 hours.

9. The preparation method according to claim 2, characterized in that In step (III), the plant fibers include bamboo fibers, hemp fibers, and kapok fibers; The mass ratio of the bamboo fiber, hemp fiber and kapok fiber is 1:(0.4-0.5):(0.2-0.3); The immersion temperature of the plant fiber in the antibacterial liquid is 40-50°C; The plant fiber is immersed in the antibacterial liquid for 25 to 35 minutes.

10. The preparation method according to claim 2, characterized in that Step (III), the operation steps of the blended hot pressing include: The modified plant fibers are fed into an opener for opening, the opened modified plant fibers are mixed with modified polypropylene fibers to obtain mixed fibers, the mixed fibers are dispersed in water to form a fiber suspension, the fiber suspension is fed into an inclined-wire wet-laid web forming machine for wet-laid web formation to obtain a fiber web; an adhesive is sprayed onto the surface of the fiber web, and then hot-pressed to obtain the diversion and antibacterial layer; The mass ratio of the modified plant fiber to the modified polypropylene fiber is (2-3):1.

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