Tea polyphenol non-woven fabric mask based on superfine grinding technology and preparation method thereof

Abstract

The invention provides a tea polyphenol non-woven fabric mask based on a superfine grinding technology and a preparation method of the tea polyphenol non-woven fabric mask. The tea polyphenol non-woven fabric mask comprises a waterproof layer, a functional layer and a skin-friendly layer which are sequentially stacked, the functional layer is obtained by soaking a non-woven fabric in functional slurry and then taking out and drying the non-woven fabric, the functional slurry is composed of tea polyphenol powder, modified zinc oxide, chitosan quaternary ammonium salt, zinc glycyrrhizinate, an adhesive and deionized water, the tea polyphenol powder is obtained by performing superfine grinding on tea polyphenol, and the modified zinc oxide is obtained by performing in-situ coating modification on nano-zinc oxide through silicon dioxide. According to the tea polyphenol non-woven fabric mask provided by the invention, the non-woven fabric mask with efficient broad-spectrum antibacterial activity, low sensitization risk and excellent air permeability is jointly constructed through the synergistic effect of specific components in the functional layer.

Description

Technical Field

[0001] The invention belongs to the technical field of mask manufacturing and relates to a tea polyphenol non-woven fabric mask based on ultrafine grinding technology and a preparation method thereof. Background Art

[0002] With the continued threat of air pollution and respiratory infections, the development of functional masks has become an important research direction in the field of personal protection. Existing technologies rely primarily on electrostatic electret technology or chemically synthesized antimicrobial agents (such as quaternary ammonium salts and silver ions) to provide antimicrobial protection. However, these solutions have significant limitations: the static decay rate of electrostatic electret materials in humid environments exceeds 90% per 24 hours, resulting in a sharp drop in filtration efficiency; while chemically synthesized antimicrobial agents are prone to triggering skin allergies (clinically reported sensitization rates >12.5%), and long-term wear can disrupt the skin's microecological balance.

[0003] In recent years, natural active ingredients (such as tea polyphenols and plant zinc) have been introduced into the research and development of masks due to their safety and antibacterial potential. However, the catechol group in the molecular structure of tea polyphenols is easily oxidized (half-life in air <2h), and the powder particle size obtained by conventional crushing technology is large (D50>15μm), and the specific surface area is insufficient, resulting in only short-term sustained release after loading (effective antibacterial time <8h). At the same time, although nano zinc oxide (ZnO) has excellent antibacterial properties, unmodified ZnO particles are prone to aggregation on the fiber surface, causing three problems: (1) the particle size of the agglomerates increases to 200-500nm, penetrating the non-woven fabric to form secondary pollution; (2) Zn 2+ The sudden release causes the local concentration to exceed the critical value (>50ppm), causing cytotoxicity; (3) it produces an antagonistic effect with tea polyphenols, reducing the synergistic antibacterial efficiency by more than 40%.

[0004] Therefore, there is an urgent need to develop a core technology that integrates ultramicro active protection, precise interface regulation and multi-functional synergy, so as to achieve the unity of efficient loading, long-term sustained release and structural stability of antibacterial ingredients while ensuring biosafety. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a tea polyphenol non-woven mask based on ultrafine grinding technology and a preparation method thereof. The tea polyphenol non-woven mask provided by the present invention constructs a non-woven mask with high efficiency and broad-spectrum antibacterial properties, low allergenic risk and excellent air permeability through the synergistic effect of specific components in the functional layer.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a tea polyphenol non-woven mask based on ultrafine grinding technology, characterized in that the tea polyphenol non-woven mask comprises a waterproof layer, a functional layer and a skin-friendly layer stacked in sequence;

[0008] The functional layer is obtained by dipping a non-woven fabric into a functional slurry and then taking it out and drying it. The functional slurry consists of tea polyphenol powder, the modified zinc oxide, chitosan quaternary ammonium salt, zinc glycyrrhizate, a binder and deionized water. The tea polyphenol powder is obtained by ultrafine grinding tea polyphenol, and the modified zinc oxide is obtained by in-situ coating and modifying nano zinc oxide with silicon dioxide.

[0009] The tea polyphenol non-woven mask provided by the present invention achieves long-lasting antibacterial, safety and comfort through the synergistic effect of specific components in the functional layer. The ultrafinely pulverized tea polyphenol powder significantly increases the specific surface area, improves the load stability of the active ingredients on the fiber, and effectively delays the oxidative inactivation of tea polyphenols. The modified zinc oxide in situ coated with silica forms a core-shell structure, and accurately controls the sustained release of zinc ions, which not only avoids secondary pollution and cytotoxicity caused by agglomeration, but also eliminates the antagonistic effect with tea polyphenols. Combined with the electrostatic adsorption of chitosan quaternary ammonium salt, the buffering and anti-inflammatory effects of zinc glycyrrhizate, and the fixing effect of the adhesive, a non-woven mask with high-efficiency and broad-spectrum antibacterial properties, low allergenic risk and excellent air permeability is constructed.

[0010] This invention uses ultrafine grinding technology to prepare tea polyphenol powder, significantly increasing the specific surface area and allowing the easily oxidized active ingredients of tea polyphenols to be more stably loaded onto the fiber carrier. This treatment significantly prolongs the effective antibacterial time and solves the technical problem of conventional tea polyphenols being rapidly inactivated in air.

[0011] The modified zinc oxide formed by in-situ coating of nano-zinc oxide with silica effectively inhibits particle agglomeration through its core-shell structure, avoiding the common problem of sudden release of zinc ions in uncoated zinc oxide. It not only prevents the risk of cytotoxicity caused by excessive local concentration, but also maintains continuous antibacterial efficacy. More importantly, it eliminates the mutual offsetting effect between zinc oxide and tea polyphenols, allowing the two to synergistically exert a stronger antibacterial effect.

[0012] The active ingredients in the functional slurry create a synergistic effect. Tea polyphenols, the main antibacterial ingredient, enhances its binding to the fiber in its ultrafine powder form. Modified zinc oxide exerts a targeted inhibitory effect against specific pathogenic microorganisms. Chitosan quaternary ammonium salt, with its cationic properties, forms a positively charged layer on the fiber surface, significantly enhancing the electrostatic adsorption capacity for negatively charged microorganisms in the air. Zinc glycyrrhizate buffers the irritation of zinc ions while also alleviating skin discomfort caused by prolonged wear through its anti-inflammatory properties. Through the complementary and coordinated functions of the different components, the functional layer achieves both long-lasting antibacterial properties, wearer comfort, and biocompatibility.

[0013] The tea polyphenols non-woven fabric mask provided by the present invention is composed of a waterproof layer, a functional layer, and a skin-friendly layer stacked in sequence. The waterproof layer effectively blocks liquid pollutants such as droplets, the skin-friendly layer provides skin contact comfort, and the functional layer carries a sustained-release system for active ingredients. The functional layer undergoes a repeated "impregnation-pressing" treatment process, allowing the active ingredients in the functional slurry to penetrate deeply into the fiber network, forming a stable functional coating. While maintaining the physical filtration function of traditional masks, the final product also obtains a sustained antibacterial ability based on natural ingredients, and avoids the skin allergy problems that may be caused by the use of chemically synthesized antibacterial agents.

[0014] As a preferred technical solution of the present invention, the waterproof layer is melt-blown PP cloth.

[0015] In some optional embodiments, the melt-blown PP fabric has a gram weight of 24 to 26 g / m 2 , for example, it can be 24g / m 2 , 24.2g / m 2 , 24.4g / m 2 , 24.6g / m 2 , 24.8g / m 2 , 25g / m 2 , 25.2g / m 2 , 25.4g / m 2 , 25.6g / m 2 , 25.8g / m 2 or 26g / m 2 , but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0016] In some optional examples, the skin-friendly layer is cotton spunlace fabric.

[0017] In some optional embodiments, the gram weight of the cotton spunlace fabric is 28 to 32 g / m 2 , for example, it can be 28g / m 2 , 28.5g / m 2 , 29g / m 2 , 29.5g / m 2 , 30g / m 2 , 30.5g / m 2 , 31g / m 2 , 31.5g / m 2 or 32g / m 2 , but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0018] In some optional embodiments, the non-woven fabric has a gram weight of 23 to 25 g / m 2 , for example, it can be 23g / m2 , 23.2g / m 2 , 23.4g / m 2 , 23.6g / m 2 , 23.8g / m 2 , 24g / m 2 , 24.2g / m 2 , 24.4g / m 2 , 24.6g / m 2 , 24.8g / m 2 or 25g / m 2 , but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0019] In a second aspect, the present invention provides a method for preparing a tea polyphenol non-woven mask based on ultrafine grinding technology, the preparation method comprising:

[0020] (I) Under an inert atmosphere, ultrafinely grinding tea polyphenols and then sieving to obtain tea polyphenol powder;

[0021] (II) dispersing nano zinc oxide in anhydrous ethanol to obtain a zinc oxide dispersion, adding dropwise a precursor solution consisting of ethyl orthosilicate, 3-aminopropyltriethoxysilane, and an ethanol aqueous solution, followed by aging, and finally centrifuging, washing, and drying to obtain a modified zinc oxide;

[0022] (III) mixing the tea polyphenol powder, the modified zinc oxide, chitosan quaternary ammonium salt, zinc glycyrrhizate, a binder, and deionized water to obtain a functional slurry, immersing the non-woven fabric in the functional slurry and then taking it out and pressing it, repeating this process at least twice, and drying to obtain a functional layer;

[0023] (IV) laminating the waterproof layer, the functional layer and the skin-friendly layer in sequence and then hot-pressing them to obtain the tea polyphenols non-woven fabric mask.

[0024] During the preparation of modified zinc oxide, the present invention in-situ coats nano-zinc oxide with silica formed by hydrolysis of ethyl orthosilicate. This core-shell structure overcomes the drawback of conventional nano-zinc oxide, which is prone to agglomeration. Unmodified zinc oxide nanoparticles easily aggregate into clusters of 200 to 500 nm, which not only penetrate the gaps between non-woven fibers and cause secondary contamination, but also lead to the sudden release of zinc ions and cytotoxicity. While the silica coating physically isolates the particles, the amino groups provided by 3-aminopropyltriethoxysilane also enhance the interfacial bonding with other components, allowing for a smooth and stable release of zinc ions.

[0025] In the functional slurry, ultrafinely ground tea polyphenol powder provides broad-spectrum antimicrobial activity, and its catechol groups remain stable under inert atmosphere. Modified zinc oxide provides targeted antimicrobial activity against specific pathogens, creating a complementary antimicrobial spectrum. The addition of chitosan quaternary ammonium salt, with its cationic properties, creates a positively charged layer on the fiber surface, enhancing the capture of negatively charged microorganisms through electrostatic adsorption. Zinc glycyrrhizate, meanwhile, provides a crucial buffering function: mitigating potential local irritation from zinc ions and reducing skin discomfort associated with prolonged wear through its anti-inflammatory properties.

[0026] The two or more pressing operations during the impregnation process ensure that the functional slurry fully penetrates deep into the fiber network. During the first impregnation, the functional slurry is mainly adsorbed on the fiber surface. Under a pressing pressure of 0.15-0.25MPa, some components are mechanically squeezed into the fiber gaps, while excess slurry is squeezed out to prevent surface agglomeration. During subsequent impregnations, the new functional slurry, with the help of the transition layer formed in the previous step, penetrates deeper into the fiber bundle and fuses with the residual components during the pressing process to form a gradient distribution. This repeated operation effectively overcomes the problem of uneven slurry distribution caused by capillary action and surface tension in a single treatment. A single impregnation can easily lead to the functional slurry being enriched in the surface layer and insufficient internal loading, or the active ingredients being squeezed out due to excessive pressing. The synergistic effect of two or more impregnations allows the functional slurry to form a multi-layered functional coating on the fiber surface, ensuring the efficient loading of active substances such as tea polyphenols powder and modified zinc oxide while maintaining the permeability of the fiber pores. Ultimately, a functional layer with high active ingredient content and gas permeability is constructed at the microscale.

[0027] The hot pressing stage adopts a gradient temperature increase. The low temperature in the pre-pressing stage avoids the decomposition of heat-sensitive substances such as tea polyphenols, while the high temperature pressing stage activates the cross-linking reaction of the adhesive, so that the three-layer fabric forms a firm composite structure.

[0028] As a preferred technical solution of the present invention, in step (I), the ultrafine grinding is carried out in an ultrafine grinding equipment, and the classification wheel speed of the ultrafine grinding equipment is 3400-3600 rpm, for example, it can be 3400 rpm, 3420 rpm, 3440 rpm, 3460 rpm, 3480 rpm, 3500 rpm, 3520 rpm, 3540 rpm, 3560 rpm, 3580 rpm or 3600 rpm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0029] In some optional examples, the feed pressure of the ultrafine grinding is 0.8 to 1 MPa, for example, it can be 0.8 MPa, 0.82 MPa, 0.84 MPa, 0.86 MPa, 0.88 MPa, 0.9 MPa, 0.92 MPa, 0.94 MPa, 0.96 MPa, 0.98 MPa or 1 MPa, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0030] In some optional examples, the particle size D50 of the tea polyphenol powder is 2 to 3 μm, for example, it can be 2.0 μm, 2.1 μm, 2.2 μm, 2.3 μm, 2.4 μm, 2.5 μm, 2.6 μm, 2.7 μm, 2.8 μm, 2.9 μm or 3.0 μm, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0031] As a preferred technical solution of the present invention, in step (II), the mass fraction of nano zinc oxide in the zinc oxide dispersion is 7.5-8.5wt%, for example, it can be 7.5wt%, 7.6wt%, 7.7wt%, 7.8wt%, 7.9wt%, 8.0wt%, 8.1wt%, 8.2wt%, 8.3wt%, 8.4wt% or 8.5wt%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0032] In some optional examples, the precursor solution is prepared by the following method:

[0033] An ethanol aqueous solution was prepared, and a hydrochloric acid solution was added dropwise to the ethanol aqueous solution to adjust the pH value thereof to 3. Then, ethyl orthosilicate and 3-aminopropyltriethoxysilane were added, and the mixture was mixed and stirred to obtain the precursor solution.

[0034] In some optional examples, the volume ratio of ethanol to deionized water in the ethanol aqueous solution 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 this numerical range are also applicable.

[0035] In some optional examples, the concentration of the hydrochloric acid solution is 0.04 to 0.06 mol / L, for example, it can be 0.04 mol / L, 0.042 mol / L, 0.044 mol / L, 0.046 mol / L, 0.048 mol / L, 0.05 mol / L, 0.052 mol / L, 0.054 mol / L, 0.056 mol / L, 0.058 mol / L or 0.06 mol / L, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0036] In some optional examples, the molar ratio of the ethyl orthosilicate to the 3-aminopropyltriethoxysilane 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.

[0037] In some optional examples, the mass fraction of ethyl orthosilicate in the precursor solution is 26 to 28 wt%, for example, it can be 26 wt%, 26.2 wt%, 26.4 wt%, 26.6 wt%, 26.8 wt%, 27 wt%, 27.2 wt%, 27.4 wt%, 27.6 wt%, 27.8 wt% or 28 wt%, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0038] In some optional examples, the mixing time 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 the numerical range are also applicable.

[0039] As a preferred technical solution of the present invention, in step (II), the dripping rate of the precursor solution is 0.8 to 1 mL / min, for example, it can be 0.8 mL / min, 0.82 mL / min, 0.84 mL / min, 0.86 mL / min, 0.88 mL / min, 0.9 mL / min, 0.92 mL / min, 0.94 mL / min, 0.96 mL / min, 0.98 mL / min or 1 mL / min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0040] In some optional examples, during the dripping process of the precursor solution, the zinc oxide dispersion is heated and stirred.

[0041] In some optional examples, the heating temperature of the zinc oxide dispersion 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.

[0042] In some optional examples, the stirring speed of the zinc oxide dispersion is 750 to 850 rpm, for example, it can be 750 rpm, 760 rpm, 770 rpm, 780 rpm, 790 rpm, 800 rpm, 810 rpm, 820 rpm, 830 rpm, 840 rpm or 850 rpm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0043] In some optional examples, the mass ratio of nano zinc oxide in the zinc oxide dispersion to ethyl orthosilicate in the precursor solution is 1:(0.35-0.45), for example, it can be 1:0.35, 1:0.36, 1:0.37, 1:0.38, 1:0.39, 1:0.4, 1:0.41, 1:0.42, 1:0.43, 1:0.44 or 1:0.45, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0044] The present invention specifically limits the mass ratio of nano-zinc oxide in the zinc oxide dispersion to ethyl orthosilicate in the precursor solution to 1:(0.35-0.45). Within this range, the silanol groups generated by the hydrolysis of ethyl orthosilicate can completely cover the active sites on the zinc oxide surface, forming a tight encapsulation layer through Si-O-Zn chemical bonds. This not only prevents the sudden release of zinc ions from defects, but also maintains a controllable ion diffusion channel, stabilizing the zinc ion release rate within a safe threshold. More importantly, the complete coating blocks direct contact between zinc oxide and tea polyphenols, eliminating the redox antagonistic effect between the two, significantly improving the synergistic antibacterial efficiency.

[0045] When the amount of ethyl orthosilicate added is lower than the lower limit of the range defined in the present invention, the total amount of silicon source is insufficient to cover all the surfaces of nano-zinc oxide, and the uncoated zinc oxide crystal surface becomes a channel for rapid dissolution of zinc ions in an aqueous environment, causing the initial release concentration to exceed the cell safety limit. These exposed areas will also be in direct contact with the catechol groups of tea polyphenols, consuming the active ingredients of tea polyphenols through redox reactions, resulting in a decrease in antibacterial efficiency. More seriously, local coating defects become stress concentration points in the subsequent padding process, and high-pressure rolling will cause local peeling of the coating layer. The peeled-off silica fragments will block the gaps between the non-woven fibers, increase the ventilation resistance of the mask, and weaken the carrying capacity of the functional layer for the active ingredients.

[0046] When the amount of ethyl orthosilicate added exceeds the upper limit of the range specified in this invention, the excess silicon source self-aggregates during the aging process to form free silica colloidal particles. These ineffective particles occupy space in the reaction system but do not participate in effective coating. During the second stage of aging, the high concentration of silicon species accelerates condensation, causing a sharp increase in system viscosity and increasing processing difficulty.

[0047] As a preferred technical solution of the present invention, in step (II), the aging process includes:

[0048] After all the precursor solutions are dropped in, a mixed solution is obtained. The mixed solution is heated to a first temperature at a first heating rate and stirred at a first speed. After being kept warm for a period of time, it is further heated to a second temperature at a second heating rate and stirred at a second speed. After being kept warm for a period of time, the aging is completed.

[0049] The purpose of the first stage of aging is to achieve rapid and uniform nucleation of the silica coating. The rapid hydrolysis of ethyl orthosilicate generates active silanol groups, forming a preliminary coating on the surface of the zinc oxide particles. The high-speed stirring generates strong turbulence, ensuring sufficient dispersion of the nanoparticles, effectively preventing zinc oxide self-agglomeration, and uniformly migrating the silicon source molecules to the particle interface. The 25-35 minute holding period provides ample time for the initial condensation of the silanol groups, promoting the formation of a continuous but loose network skeleton in the coating.

[0050] The purpose of the second stage of aging is to achieve the densification and structural stabilization of the coating layer. The temperature is slowly increased in the second stage, and the violent thermal motion of the solvent molecules significantly reduces the viscosity of the medium, driving the siloxane segments to flow and fill the defects on the surface of zinc oxide. At this time, the stirring speed is reduced to maintain the weak turbulence required for particle suspension and greatly reduce the shear force to prevent mechanical damage to the uncured silicon layer. During the 55-65min insulation process, the silanol group continues to dehydrate and condense at high temperature, converting the initial loose network into a dense Si-O-Si cross-linked structure. At the same time, the amino functional groups of 3-aminopropyltriethoxysilane are enriched on the surface of the coating layer under heat drive, forming active sites for subsequent bonding with organic components.

[0051] In some optional examples, the first heating rate is 0.8 to 1.2°C / min, for example, it can be 0.8°C / min, 0.85°C / min, 0.9°C / min, 0.95°C / min, 1.0°C / min, 1.05°C / min, 1.1°C / min, 1.15°C / min or 1.2°C / min, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0052] In some optional examples, the first temperature is 63-65°C, for example, it can be 63°C, 63.2°C, 63.4°C, 63.6°C, 63.8°C, 64°C, 64.2°C, 64.4°C, 64.6°C, 64.8°C or 65°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0053] In some optional examples, the first rotational speed is 750-850 rpm, for example, it can be 750 rpm, 760 rpm, 770 rpm, 780 rpm, 790 rpm, 800 rpm, 810 rpm, 820 rpm, 830 rpm, 840 rpm or 850 rpm, 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 first temperature is kept warm for 25 to 35 minutes, for example, 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 the numerical range are also applicable.

[0055] In some optional examples, the second heating rate is 0.4 to 0.6°C / min, for example, it can be 0.4°C / min, 0.42°C / min, 0.44°C / min, 0.46°C / min, 0.48°C / min, 0.5°C / min, 0.52°C / min, 0.54°C / min, 0.56°C / min, 0.58°C / min or 0.6°C / min, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0056] In some optional examples, the second temperature is 73-75°C, for example, it can be 73°C, 73.2°C, 73.4°C, 73.6°C, 73.8°C, 74°C, 74.2°C, 74.4°C, 74.6°C, 74.8°C or 75°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0057] In some optional examples, the second speed is 350-450 rpm, for example, it can be 350 rpm, 360 rpm, 370 rpm, 380 rpm, 390 rpm, 400 rpm, 410 rpm, 420 rpm, 430 rpm, 440 rpm or 450 rpm, 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 second temperature is kept warm for 55 to 65 minutes, for example, 55 minutes, 56 minutes, 57 minutes, 58 minutes, 59 minutes, 60 minutes, 61 minutes, 62 minutes, 63 minutes, 64 minutes or 65 minutes, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0059] As a preferred technical solution of the present invention, in step (III), the mass fraction of tea polyphenol powder in the functional slurry is 11 to 12 wt%, for example, it can be 11 wt%, 11.1 wt%, 11.2 wt%, 11.3 wt%, 11.4 wt%, 11.5 wt%, 11.6 wt%, 11.7 wt%, 11.8 wt%, 11.9 wt% or 12 wt%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0060] The present invention specifically limits the mass fraction of tea polyphenols powder in the functional slurry to 11-12wt%. Within this range, it is ensured that the functional layer has sufficient active ingredients to achieve long-term antibacterial effect. The tea polyphenols after ultrafine grinding have a significantly increased specific surface area, and their catechol groups can form a denser molecular network in the slurry system. In addition, the 11-12wt% tea polyphenols powder forms a continuous covering layer on the surface of the non-woven fabric fiber, which not only avoids the sparse active site defect at low concentrations, but also produces electrostatic complexation with the cationic properties of chitosan quaternary ammonium salt, synergistically improving the penetration efficiency of microbial cell membranes. At the same time, a synergistic effect is generated between the concentration range of 11-12wt% and the modified zinc oxide of 7-8wt%. The silica coating blocks the direct contact between tea polyphenols and zinc oxide, eliminating the antagonistic effect caused by the redox reaction between the two. Instead, the sustained release of zinc ions complements the free radical scavenging ability of tea polyphenols, greatly improving the antibacterial efficiency.

[0061] When the mass fraction of tea polyphenol powder is less than 11wt%, the active material loading of the functional layer is low. On the one hand, the low tea polyphenol concentration cannot form a continuous functional film layer on the fiber surface, resulting in uneven distribution of antimicrobial ingredients. The continuous impact of respiratory moisture will accelerate the local loss of active ingredients, significantly reducing the effective antibacterial duration. On the other hand, the insufficient concentration of tea polyphenol powder will weaken the synergistic effect of the entire composite system, weaken the tea polyphenol powder's chelating ability for metal ions, and lead to an enhanced tendency of zinc ion burst release from the modified zinc oxide. At the same time, due to the lack of sufficient molecular bridging effect of tea polyphenols, the positive charge distribution density of chitosan quaternary ammonium salt decreases, reducing the capture efficiency of negatively charged pathogens.

[0062] When the mass fraction of tea polyphenol powder exceeds 12wt%, the excessively high concentration first leads to a significant increase in the slurry viscosity. During the impregnation process, the slurry has difficulty penetrating deep into the interstices between non-woven fibers, instead forming a colloidal accumulation layer on the surface. During the subsequent hot air drying stage, the surface tea polyphenols will rapidly oxidize and cross-link due to local oversaturation, forming brown agglomerates that block the fiber pores and reduce the air permeability of the mask. More seriously, excessive tea polyphenol powder can break through the isolation of the modified zinc oxide silica coating. Its catechol groups directly reduce the zinc ions in the zinc oxide lattice, not only inactivating the metal active ingredients but also generating quinone antagonists that inhibit the antibacterial activity of chitosan quaternary ammonium salt.

[0063] In some optional examples, the mass fraction of modified zinc oxide in the functional slurry is 7 to 8 wt%, for example, it can be 7.0 wt%, 7.1 wt%, 7.2 wt%, 7.3 wt%, 7.4 wt%, 7.5 wt%, 7.6 wt%, 7.7 wt%, 7.8 wt%, 7.9 wt% or 8.0 wt%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0064] The present invention specifically limits the mass fraction of modified zinc oxide in the functional slurry to 7-8wt%. Within this range, the zinc oxide in situ coated with silica can fully exert its triple effects: first, the silica coating layer accurately controls the sustained-release rate of zinc ions, avoiding the sudden increase in zinc ion concentration causing cytotoxicity, while maintaining a long-term antibacterial concentration; second, the loading amount forms a synergistic effect with tea polyphenol powder (11-12wt%), and enhances the destructive power to bacterial biofilms through the coordination effect between metal ions and phenolic hydroxyl groups; third, the amino groups on its surface from 3-aminopropyltriethoxysilane produce electrostatic self-assembly with chitosan quaternary ammonium salt, constructing a dense antibacterial network on the fiber surface, which significantly improves the antibacterial rate.

[0065] When the mass fraction of modified zinc oxide is lower than 7wt%, the ionic antibacterial efficiency of the functional layer is significantly reduced, and the amount of zinc ion released is insufficient to maintain the minimum inhibitory concentration. In particular, the inhibition time against drug-resistant Staphylococcus aureus is significantly shortened. At the same time, the low concentration of modified zinc oxide causes the zinc oxide particles to be sparsely distributed on the fiber, unable to form a continuous protective layer, making it easy for pathogens to invade through the gaps between the particles. More importantly, the lack of sufficient zinc ions to chelate with tea polyphenols will weaken the electron transfer efficiency of tea polyphenols, resulting in a decrease in the free radical scavenging ability of the composite system and a simultaneous decrease in antiviral activity.

[0066] When the mass fraction of modified zinc oxide exceeds 8wt%, the excessive modified zinc oxide particles rapidly absorb free water during the impregnation process due to their large specific surface area, causing the slurry viscosity to increase dramatically and resulting in a decrease in the deep penetration rate of the nonwoven fabric. During the drying stage, the excess modified zinc oxide migrates to the fiber surface and accumulates. During hot pressing, local stress concentration causes the coating to rupture, and the sudden release concentration of zinc ions exceeds the safety threshold.

[0067] In some optional examples, the mass fraction of chitosan quaternary ammonium salt in the functional slurry is 5.5-6wt%, for example, it can be 5.5wt%, 5.55wt%, 5.6wt%, 5.65wt%, 5.7wt%, 5.75wt%, 5.8wt%, 5.85wt%, 5.9wt%, 5.95wt% or 6.0wt%, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0068] The present invention specifically limits the mass fraction of chitosan quaternary ammonium salt in the functional slurry to 5.5-6wt%. Within this range, the chitosan quaternary ammonium salt forms a continuous positive charge layer on the fiber surface by virtue of its high-density quaternary ammonium cations, thereby achieving electrostatic capture of negatively charged pathogens; the amino groups in its molecular chain form a hydrogen bond network with the catechol groups of tea polyphenols, thereby inhibiting the oxidation of tea polyphenols and enhancing the ductility of the functional membrane; at the same time, through the ionic coupling of the quaternary ammonium groups and the silanol groups on the surface of the modified zinc oxide, the dispersion uniformity of the modified zinc oxide is improved, thereby avoiding the risk of secondary pollution caused by agglomeration.

[0069] When the mass fraction of chitosan quaternary ammonium salt is less than 5.5wt%, the positive charge density is insufficient, the charge coverage of the fiber surface decreases, and the capture efficiency of viral aerosols with a particle size of less than 1μm is reduced. In addition, due to the lack of sufficient molecular bridging, tea polyphenols and zinc oxide phase separate in the slurry, and after drying, the functional layer shows an "island distribution" defect of active ingredients. More importantly, low concentrations of chitosan quaternary ammonium salt cannot completely encapsulate the modified zinc oxide particles. The unshielded zinc ions dissolve faster in a humid environment, resulting in local concentrations exceeding the standard and causing skin tingling.

[0070] When the mass fraction of chitosan quaternary ammonium salt exceeds 6wt%, the excess cationic polymer causes the slurry viscosity to surge, blocking the micropores of the nonwoven fabric during impregnation and resulting in insufficient penetration of the functional slurry. After drying, the excess quaternary ammonium salt crystallizes between the fibers, forming a hard, prismatic structure. This not only reduces the mask's flexibility but also causes cracking in the functional layer due to crystallization expansion during the hot pressing stage. Furthermore, high concentrations of quaternary ammonium groups can disrupt the skin's microecological balance, reducing the diversity of the resident bacterial flora and inducing the risk of contact dermatitis.

[0071] In some optional examples, the mass fraction of zinc glycyrrhizate in the functional slurry is 3.2 to 3.8 wt%, for example, it can be 3.2 wt%, 3.25 wt%, 3.3 wt%, 3.35 wt%, 3.4 wt%, 3.45 wt%, 3.5 wt%, 3.55 wt%, 3.6 wt%, 3.65 wt%, 3.7 wt%, 3.75 wt% or 3.8 wt%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0072] The present invention specifically limits the mass fraction of zinc glycyrrhizate in the functional slurry to 3.2-3.8wt%. Within this range, the triterpenoid saponin structure of zinc glycyrrhizate forms a stable complex with zinc ions, neutralizing the potential irritation of zinc oxide. Its surfactant properties also reduce the interfacial tension of the slurry, promoting uniform spreading of tea polyphenols / zinc oxide on the fiber surface. Furthermore, zinc glycyrrhizate acts as a natural free radical scavenger, and its aglycone structure captures semiquinone radicals generated by the oxidation of tea polyphenols, improving the antioxidant stability of the functional layer and synergistically enhancing the inactivation efficiency of respiratory viruses.

[0073] When the mass fraction of zinc glycyrrhizate is lower than 3.2wt%, zinc glycyrrhizate cannot completely chelate free zinc ions, and local Zn 2+ The concentration exceeds the sensitization threshold and induces skin erythema reaction; in addition, due to the lack of sufficient saponin emulsification effect, tea polyphenol particles tend to agglomerate into aggregates larger than 5μm during the drying process, resulting in antibacterial blind spots in the functional layer.

[0074] When the mass fraction of zinc glycyrrhizate exceeds 3.8wt%, the excess saponin forms a micellar layer on the fiber surface, blocking the pores of the nonwoven fabric and causing a decrease in air permeability. Furthermore, the excess zinc glycyrrhizate competes with the phenolic hydroxyl binding sites of tea polyphenols, blocking their antibacterial synergistic pathway with modified zinc oxide, and thus reducing the antibacterial rate of the functional layer.

[0075] In some optional examples, the mass fraction of the binder in the functional slurry is 2.8 to 3.2 wt%, for example, it can be 2.8 wt%, 2.85 wt%, 2.9 wt%, 2.95 wt%, 3.0 wt%, 3.05 wt%, 3.1 wt%, 3.15 wt% or 3.2 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 adhesive is water-based polyurethane, and the solid content of the water-based polyurethane is 35-45%, for example, it can be 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44% or 45%, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0077] As a preferred technical solution of the present invention, in step (III), the single immersion time of the non-woven fabric is 35 to 45 seconds, for example, it can be 35 seconds, 36 seconds, 37 seconds, 38 seconds, 39 seconds, 40 seconds, 41 seconds, 42 seconds, 43 seconds, 44 seconds or 45 seconds, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0078] In some optional examples, the impregnation temperature of the non-woven fabric is 25-35°C, for example, it can be 25°C, 26°C, 27°C, 28°C, 29°C, 30°C, 31°C, 32°C, 33°C, 34°C or 35°C, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0079] In some optional examples, the single pressing pressure of the non-woven fabric is 0.15 to 0.25 MPa, for example, it can be 0.15 MPa, 0.16 MPa, 0.17 MPa, 0.18 MPa, 0.19 MPa, 0.2 MPa, 0.21 MPa, 0.22 MPa, 0.23 MPa, 0.24 MPa or 0.25 MPa, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0080] In some optional examples, the single pressing time of the non-woven fabric is 2.5 to 3.5 s, for example, it can be 2.5 s, 2.6 s, 2.7 s, 2.8 s, 2.9 s, 3.0 s, 3.1 s, 3.2 s, 3.3 s, 3.4 s or 3.5 s, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0081] In some optional examples, the drying method is hot air drying.

[0082] In some optional examples, the hot air drying 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.

[0083] In some optional examples, the wind speed of the hot air drying is 11 to 13 m / s, for example, it can be 11 m / s, 11.2 m / s, 11.4 m / s, 11.6 m / s, 11.8 m / s, 12 m / s, 12.2 m / s, 12.4 m / s, 12.6 m / s, 12.8 m / s or 13 m / s, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0084] In some optional examples, the hot air drying time is 4 to 6 minutes, for example, it can be 4.0 minutes, 4.2 minutes, 4.4 minutes, 4.6 minutes, 4.8 minutes, 5.0 minutes, 5.2 minutes, 5.4 minutes, 5.6 minutes, 5.8 minutes or 6.0 minutes, but it is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0085] As a preferred technical solution of the present invention, in step (IV), the hot pressing process includes a pre-pressing stage and a pressing stage performed sequentially.

[0086] During the pre-pressing stage, the low temperature and low pressure environment is used to prevent the decomposition of heat-sensitive substances such as tea polyphenols, while the water-based polyurethane adhesive is initially softened and melted, prompting the three layers of fabric to form a preliminary bond and expel bubbles between the layers.

[0087] During the pressing stage, the cross-linking and curing reaction of the adhesive is thoroughly activated through high temperature and high pressure. The high temperature causes the polyurethane molecular segments to move violently to form a dense network structure, while the high pressure drives the molten adhesive to penetrate and anchor into the fiber gaps. At the same time, the high temperature promotes the chemical bonding between the silica coating and the organic components in the functional layer.

[0088] The gradient hot pressing process not only avoids the risk of thermal damage to tea polyphenols and chitosan by direct high temperature, but also significantly improves the interlayer peeling strength by utilizing high temperature and high pressure in the later stage, taking into account both structural strength and toughness and the activity of effective ingredients.

[0089] In some optional examples, the pressure in the pre-pressing stage is 0.4 to 0.6 MPa, for example, it can be 0.4 MPa, 0.42 MPa, 0.44 MPa, 0.46 MPa, 0.48 MPa, 0.5 MPa, 0.52 MPa, 0.54 MPa, 0.56 MPa, 0.58 MPa or 0.6 MPa, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0090] In some optional examples, the temperature in the pre-pressing stage is 74-76°C, for example, it can be 74°C, 74.2°C, 74.4°C, 74.6°C, 74.8°C, 75°C, 75.2°C, 75.4°C, 75.6°C, 75.8°C or 76°C, 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 holding time of the pre-pressing stage is 25 to 35 seconds, for example, it can be 25 seconds, 26 seconds, 27 seconds, 28 seconds, 29 seconds, 30 seconds, 31 seconds, 32 seconds, 33 seconds, 34 seconds or 35 seconds, 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 pressure in the pressing stage is 2.5 to 3 MPa, for example, it can be 2.5 MPa, 2.55 MPa, 2.6 MPa, 2.65 MPa, 2.7 MPa, 2.75 MPa, 2.8 MPa, 2.85 MPa, 2.9 MPa, 2.95 MPa or 3 MPa, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0093] In some optional embodiments, the temperature in the pressing stage is 110-120°C, for example, it can be 110°C, 111°C, 112°C, 113°C, 114°C, 115°C, 116°C, 117°C, 118°C, 119°C or 120°C, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0094] In some optional examples, the holding time of the pressing stage is 85 to 95 seconds, for example, it can be 85 seconds, 86 seconds, 87 seconds, 88 seconds, 89 seconds, 90 seconds, 91 seconds, 92 seconds, 93 seconds, 94 seconds or 95 seconds, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0095] Compared with the prior art, the present invention has the following beneficial effects:

[0096] The tea polyphenol non-woven mask provided by the present invention achieves long-lasting antibacterial, safety and comfort through the synergistic effect of specific components in the functional layer. The ultrafinely pulverized tea polyphenol powder significantly increases the specific surface area, improves the load stability of the active ingredients on the fiber, and effectively delays the oxidative inactivation of tea polyphenols. The modified zinc oxide in situ coated with silica forms a core-shell structure, and accurately controls the sustained release of zinc ions, which not only avoids secondary pollution and cytotoxicity caused by agglomeration, but also eliminates the antagonistic effect with tea polyphenols. Combined with the electrostatic adsorption of chitosan quaternary ammonium salt, the buffering and anti-inflammatory effects of zinc glycyrrhizate, and the fixing effect of the adhesive, a non-woven mask with high-efficiency and broad-spectrum antibacterial properties, low allergenic risk and excellent air permeability is constructed. BRIEF DESCRIPTION OF THE DRAWINGS

[0097] Figure 1 A flow chart of the preparation process of the tea polyphenols non-woven mask provided in Examples 1-15 of the present invention;

[0098] Figure 2 This is the E. coli colony image of untreated non-woven fabric;

[0099] Figure 3 This is a colony image of Escherichia coli in the functional layer prepared in Example 1 of the present invention;

[0100] Figure 4 Figure 1 is a colony image of Staphylococcus aureus on untreated nonwoven fabric;

[0101] Figure 5 This is a colony image of Staphylococcus aureus in the functional layer prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0102] 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.

[0103] Example 1

[0104] This embodiment provides a method for preparing a tea polyphenols non-woven mask based on ultrafine grinding technology, such as Figure 1 As shown, the preparation method comprises:

[0105] (1) Under a nitrogen atmosphere, tea polyphenols were ultrafinely pulverized using an ultrafine pulverizing device. The classifying wheel speed of the ultrafine pulverizing device was 3400 rpm, and the feed pressure of the ultrafine pulverization was 0.8 MPa. After ultrafine pulverization, the powder was sieved to obtain tea polyphenol powder with a particle size D50 of 2 μm.

[0106] (2) dispersing nano zinc oxide in anhydrous ethanol to obtain a zinc oxide dispersion, wherein the mass fraction of nano zinc oxide in the zinc oxide dispersion is 7.5 wt %;

[0107] Ethanol and deionized water were mixed in a volume ratio of 3.5:1 to obtain an ethanol aqueous solution, 0.04 mol / L hydrochloric acid solution was added dropwise to the ethanol aqueous solution to adjust its pH to 3, and then ethyl orthosilicate and 3-aminopropyltriethoxysilane were added in a molar ratio of ethyl orthosilicate to 3-aminopropyltriethoxysilane of 3.5:1. The mixture was mixed and stirred for 25 minutes to obtain a precursor solution, wherein the mass fraction of ethyl orthosilicate in the precursor solution was 26 wt %;

[0108] The precursor solution was added dropwise to the zinc oxide dispersion at a rate of 0.8 mL / min at a heating temperature of 50° C. and a stirring speed of 750 rpm. The mass ratio of nano zinc oxide in the zinc oxide dispersion to ethyl orthosilicate in the precursor solution was 1:0.35.

[0109] After all the precursor solutions were added dropwise to obtain a mixed solution, the mixed solution was heated to 63°C at a heating rate of 0.8°C / min and stirred at a speed of 750 rpm. After keeping warm for 35 minutes, the mixed solution was further heated to 73°C at a heating rate of 0.4°C / min and stirred at a speed of 350 rpm. The mixture was kept warm for 65 minutes to complete aging. The mixture was then centrifuged, washed, and dried to obtain modified zinc oxide.

[0110] (3) tea polyphenol powder, modified zinc oxide, chitosan quaternary ammonium salt, zinc glycyrrhizate, waterborne polyurethane (solid content 35%) and deionized water were mixed to obtain a functional slurry, wherein the mass fraction of tea polyphenol powder in the functional slurry was 11 wt %, the mass fraction of modified zinc oxide was 7.8 wt %, the mass fraction of chitosan quaternary ammonium salt was 5.8 wt %, the mass fraction of zinc glycyrrhizate was 3.6 wt %, and the mass fraction of waterborne polyurethane was 3 wt %;

[0111] The gram weight is 23g / m 2 The non-woven fabric was immersed in the functional slurry at 25°C for 45 seconds, then taken out and pressed at a pressure of 0.15 MPa for 3.5 seconds, repeated twice, and then dried with hot air at 50°C at a wind speed of 13 m / s for 6 minutes to obtain a functional layer;

[0112] (4) melt-blown PP cloth (weight 24g / m 2 ), functional layer and cotton spunlace fabric (weight 28g / m 2 ) are stacked in sequence, pre-pressed at a pressure of 0.4 MPa and a temperature of 76°C for 35 seconds, and then pressed at a pressure of 2.5 MPa and a temperature of 120°C for 95 seconds, and the tea polyphenols non-woven mask is obtained after cooling.

[0113] The antibacterial performance of the functional layer prepared in this embodiment was tested, and the specific testing steps are as follows:

[0114] Prepare the non-woven fabric without impregnation treatment and the functional layer prepared by the present invention, take (0.75±0.05)g of the sample to be tested, cut it into 0.5cm 2 The fragments of different sizes were placed in a conical flask and autoclaved at 121 °C for 15 min;

[0115] Dissolve 4.5 g of nutrient broth powder in 250 mL of deionized water and sterilize by autoclaving at 121°C for 15 min to obtain nutrient broth.

[0116] Weigh 7.1 g of disodium hydrogen phosphate dodecahydrate and 1.36 g of potassium dihydrogen phosphate, dissolve them in 1 L of deionized water, adjust the pH to 7.2 after they are fully dissolved, divide the mixture into conical flasks, seal the flasks, and place them in a high-temperature sterilizer at 121°C for 15 min to obtain PBS buffer solution;

[0117] Weigh 33 g of nutrient agar powder and dissolve it in 1000 mL of deionized water. Shake thoroughly and distribute the mixture into conical flasks. Seal the flasks and place them in a high-temperature sterilizer at 121°C for 15 min.

[0118] Use an inoculating loop to take a small amount of bacteria from the slant of the culture tube and place it in a conical flask containing 20 mL of nutrient broth. Incubate at 37 ± 1 ° C and 130 r / min for 18 to 24 h to obtain an inoculum suspension. Dilute the cultured bacteria to 1 × 10 7 ~1×10 8 cfu / mL for standby use;

[0119] The sterilized sample to be tested was added to a conical flask containing 70 mL of PBS buffer solution, followed by 5 mL of a bacterial suspension diluted to a certain concentration. The thoroughly mixed conical flask was placed in a constant temperature shaking box to allow the bacteria and sample to be in contact with each other at 24°C and 180 rpm for 18 hours.

[0120] Then, 1 mL of the bacterial solution after contact with the sample was aspirated and inoculated into a sterilized culture dish. An appropriate amount of nutrient agar was poured in and gently shaken. After solidification, the culture dish was placed in a constant temperature incubator and cultured at 37°C for 18 to 24 hours. The colonies in the culture dish were observed and photographed. Figure 2 、 Figure 3 、 Figure 4 and Figure 5 Colony diagram.

[0121] Depend on Figure 2 、 Figure 3 、 Figure 4 and Figure 5 It can be seen from the colony diagram that there are many colonies in the culture dish of the non-woven fabric without any treatment, and there is almost no colony growth on the culture medium of the functional layer prepared in this embodiment, which shows that the functional layer treated with the functional slurry has an excellent antibacterial effect.

[0122] Example 2

[0123] This embodiment provides a method for preparing a tea polyphenols non-woven mask based on ultrafine grinding technology, such as Figure 1 As shown, the preparation method comprises:

[0124] (1) Under a nitrogen atmosphere, tea polyphenols were ultrafinely pulverized using an ultrafine pulverizing device. The classifying wheel speed of the ultrafine pulverizing device was 3450 rpm, and the feed pressure of the ultrafine pulverization was 0.85 MPa. After ultrafine pulverization, the powder was sieved to obtain tea polyphenol powder with a particle size D50 of 2.2 μm.

[0125] (2) dispersing nano zinc oxide in anhydrous ethanol to obtain a zinc oxide dispersion, wherein the mass fraction of nano zinc oxide in the zinc oxide dispersion is 7.8 wt %;

[0126] Ethanol and deionized water were mixed in a volume ratio of 3.8:1 to obtain an ethanol aqueous solution, 0.045 mol / L hydrochloric acid solution was added dropwise to the ethanol aqueous solution to adjust its pH to 3, and then ethyl orthosilicate and 3-aminopropyltriethoxysilane were added in a molar ratio of ethyl orthosilicate to 3-aminopropyltriethoxysilane of 3.8:1. The mixture was mixed and stirred for 28 minutes to obtain a precursor solution, wherein the mass fraction of ethyl orthosilicate in the precursor solution was 26.5 wt %;

[0127] The precursor solution was added dropwise to the zinc oxide dispersion at a rate of 0.85 mL / min at a heating temperature of 52° C. and a stirring speed of 780 rpm. The mass ratio of nano zinc oxide in the zinc oxide dispersion to ethyl orthosilicate in the precursor solution was 1:0.38.

[0128] After all the precursor solutions were added dropwise to obtain a mixed solution, the mixed solution was heated to 63.5°C at a heating rate of 0.9°C / min and stirred at a speed of 780 rpm. After being kept warm for 32 minutes, the mixed solution was further heated to 73.5°C at a heating rate of 0.45°C / min and stirred at a speed of 380 rpm. The mixture was kept warm for 62 minutes to complete aging. The mixture was then centrifuged, washed, and dried to obtain modified zinc oxide.

[0129] (3) tea polyphenol powder, modified zinc oxide, chitosan quaternary ammonium salt, zinc glycyrrhizate, waterborne polyurethane (solid content 38%) and deionized water were mixed to obtain a functional slurry, wherein the mass fraction of tea polyphenol powder in the functional slurry was 11.1 wt %, the mass fraction of modified zinc oxide was 8 wt %, the mass fraction of chitosan quaternary ammonium salt was 5.5 wt %, the mass fraction of zinc glycyrrhizate was 3.8 wt %, and the mass fraction of waterborne polyurethane was 2.8 wt %;

[0130] The gram weight is 23.5g / m 2 The non-woven fabric was immersed in the functional slurry at 28°C for 42 seconds, then taken out and pressed at a pressure of 0.18 MPa for 3.2 seconds, repeated twice, and then dried with hot air at 52°C at a wind speed of 12.5 m / s for 5.5 minutes to obtain a functional layer;

[0131] (4) melt-blown PP cloth (weight 24.5g / m 2 ), functional layer and cotton spunlace fabric (weight 29g / m 2 ) are stacked in sequence, pre-pressed at a pressure of 0.45 MPa and a temperature of 75.5°C for 32 seconds, and then pressed at a pressure of 2.6 MPa and a temperature of 118°C for 92 seconds, and the tea polyphenols non-woven mask is obtained after cooling.

[0132] Example 3

[0133] This embodiment provides a method for preparing a tea polyphenols non-woven mask based on ultrafine grinding technology, such as Figure 1 As shown, the preparation method comprises:

[0134] (1) Under a nitrogen atmosphere, tea polyphenols were ultrafinely pulverized using an ultrafine pulverization equipment. The classifying wheel speed of the ultrafine pulverization equipment was 3500 rpm, and the feed pressure of the ultrafine pulverization was 0.9 MPa. After ultrafine pulverization, the powder was sieved to obtain tea polyphenol powder with a particle size D50 of 2.5 μm.

[0135] (2) dispersing nano zinc oxide in anhydrous ethanol to obtain a zinc oxide dispersion, wherein the mass fraction of nano zinc oxide in the zinc oxide dispersion is 8 wt %;

[0136] Ethanol and deionized water were mixed in a volume ratio of 4:1 to obtain an ethanol aqueous solution, 0.05 mol / L hydrochloric acid solution was added dropwise to the ethanol aqueous solution to adjust its pH to 3, and then ethyl orthosilicate and 3-aminopropyltriethoxysilane were added in a molar ratio of ethyl orthosilicate to 3-aminopropyltriethoxysilane of 4:1. The mixture was stirred for 30 minutes to obtain a precursor solution, wherein the mass fraction of ethyl orthosilicate in the precursor solution was 27 wt %;

[0137] The precursor solution was added dropwise to the zinc oxide dispersion at a rate of 0.9 mL / min at a heating temperature of 55° C. and a stirring speed of 800 rpm. The mass ratio of nano zinc oxide in the zinc oxide dispersion to ethyl orthosilicate in the precursor solution was 1:0.4.

[0138] After all the precursor solutions were added dropwise to obtain a mixed solution, the mixed solution was heated to 64°C at a heating rate of 1°C / min and stirred at 800 rpm. After being kept warm for 30 minutes, the mixed solution was further heated to 74°C at a heating rate of 0.5°C / min and stirred at 400 rpm. The mixture was kept warm for 60 minutes to complete aging. The mixture was then centrifuged, washed, and dried to obtain modified zinc oxide.

[0139] (3) tea polyphenol powder, modified zinc oxide, chitosan quaternary ammonium salt, zinc glycyrrhizate, waterborne polyurethane (solid content 40%) and deionized water were mixed to obtain a functional slurry, wherein the mass fraction of tea polyphenol powder in the functional slurry was 11.5 wt %, the mass fraction of modified zinc oxide was 7.5 wt %, the mass fraction of chitosan quaternary ammonium salt was 5.6 wt %, the mass fraction of zinc glycyrrhizate was 3.4 wt %, and the mass fraction of waterborne polyurethane was 3.2 wt %;

[0140] The weight is 24g / m 2The non-woven fabric was immersed in the functional slurry at 30°C for 40 seconds, then taken out and pressed at a pressure of 0.2 MPa for 3 seconds, repeated twice, and then dried with hot air at 55°C at a wind speed of 12 m / s for 5 minutes to obtain a functional layer;

[0141] (4) melt-blown PP cloth (weight 25g / m 2 ), functional layer and cotton spunlace fabric (weight 30g / m 2 ) are stacked in sequence, pre-pressed at a pressure of 0.5 MPa and a temperature of 75°C for 30 seconds, then pressed at a pressure of 2.7 MPa and a temperature of 115°C for 90 seconds, and the tea polyphenols non-woven mask is obtained after cooling.

[0142] Example 4

[0143] This embodiment provides a method for preparing a tea polyphenols non-woven mask based on ultrafine grinding technology, such as Figure 1 As shown, the preparation method comprises:

[0144] (1) Under a nitrogen atmosphere, tea polyphenols were ultrafinely pulverized using an ultrafine pulverizing device. The classifying wheel speed of the ultrafine pulverizing device was 3550 rpm, and the feed pressure of the ultrafine pulverization was 0.95 MPa. After ultrafine pulverization, the powder was sieved to obtain tea polyphenol powder with a particle size D50 of 2.8 μm.

[0145] (2) dispersing nano zinc oxide in anhydrous ethanol to obtain a zinc oxide dispersion, wherein the mass fraction of nano zinc oxide in the zinc oxide dispersion is 8.2 wt %;

[0146] Ethanol and deionized water were mixed in a volume ratio of 4.2:1 to obtain an ethanol aqueous solution, 0.055 mol / L hydrochloric acid solution was added dropwise to the ethanol aqueous solution to adjust its pH to 3, and then ethyl orthosilicate and 3-aminopropyltriethoxysilane were added in a molar ratio of ethyl orthosilicate to 3-aminopropyltriethoxysilane of 4.2:1. The mixture was mixed and stirred for 32 minutes to obtain a precursor solution, wherein the mass fraction of ethyl orthosilicate in the precursor solution was 27.5 wt %;

[0147] The precursor solution was added dropwise to the zinc oxide dispersion at a rate of 0.95 mL / min at a heating temperature of 58° C. and a stirring speed of 820 rpm. The mass ratio of nano zinc oxide in the zinc oxide dispersion to ethyl orthosilicate in the precursor solution was 1:0.42.

[0148] After all the precursor solutions were added dropwise to obtain a mixed solution, the mixed solution was heated to 64.5°C at a heating rate of 1.1°C / min and stirred at a speed of 820 rpm. After being kept warm for 28 minutes, the mixed solution was further heated to 74.5°C at a heating rate of 0.55°C / min and stirred at a speed of 420 rpm. The mixture was kept warm for 58 minutes to complete aging. The mixture was then centrifuged, washed, and dried to obtain modified zinc oxide.

[0149] (3) tea polyphenol powder, modified zinc oxide, chitosan quaternary ammonium salt, zinc glycyrrhizate, waterborne polyurethane (solid content 42%) and deionized water were mixed to obtain a functional slurry, wherein the mass fraction of tea polyphenol powder in the functional slurry was 11.8 wt %, the mass fraction of modified zinc oxide was 7 wt %, the mass fraction of chitosan quaternary ammonium salt was 6 wt %, the mass fraction of zinc glycyrrhizate was 3.6 wt %, and the mass fraction of waterborne polyurethane was 2.8 wt %;

[0150] The gram weight is 24.5g / m 2 The non-woven fabric was immersed in a functional slurry at 32°C for 38 seconds, then taken out and pressed at a pressure of 0.22 MPa for 2.8 seconds, repeated three times, and then dried with hot air at 58°C at a wind speed of 11.5 m / s for 4.5 minutes to obtain a functional layer;

[0151] (4) melt-blown PP cloth (weight 25.5g / m 2 ), functional layer and cotton spunlace fabric (weight 31g / m 2 ) are stacked in sequence, pre-pressed at a pressure of 0.55 MPa and a temperature of 74.5°C for 28 seconds, and then pressed at a pressure of 2.8 MPa and a temperature of 112°C for 88 seconds, and the tea polyphenols non-woven mask is obtained after cooling.

[0152] Example 5

[0153] This embodiment provides a method for preparing a tea polyphenols non-woven mask based on ultrafine grinding technology, such as Figure 1 As shown, the preparation method comprises:

[0154] (1) Under a nitrogen atmosphere, tea polyphenols were ultrafinely pulverized using an ultrafine pulverizing device. The classifying wheel speed of the ultrafine pulverizing device was 3600 rpm, and the feed pressure of the ultrafine pulverization was 1 MPa. After ultrafine pulverization, the powder was sieved to obtain tea polyphenol powder with a particle size D50 of 3 μm.

[0155] (2) dispersing nano zinc oxide in anhydrous ethanol to obtain a zinc oxide dispersion, wherein the mass fraction of nano zinc oxide in the zinc oxide dispersion is 8.5 wt %;

[0156] Ethanol and deionized water were mixed in a volume ratio of 4.5:1 to obtain an ethanol aqueous solution, 0.06 mol / L hydrochloric acid solution was added dropwise to the ethanol aqueous solution to adjust its pH to 3, and then ethyl orthosilicate and 3-aminopropyltriethoxysilane were added in a molar ratio of ethyl orthosilicate to 3-aminopropyltriethoxysilane of 4.5:1. The mixture was mixed and stirred for 35 minutes to obtain a precursor solution, wherein the mass fraction of ethyl orthosilicate in the precursor solution was 28 wt %;

[0157] The precursor solution was added dropwise to the zinc oxide dispersion at a rate of 1 mL / min at a heating temperature of 60° C. and a stirring speed of 850 rpm. The mass ratio of nano zinc oxide in the zinc oxide dispersion to ethyl orthosilicate in the precursor solution was 1:0.45.

[0158] After all the precursor solutions were added dropwise to obtain a mixed solution, the mixed solution was heated to 65°C at a heating rate of 1.2°C / min and stirred at a speed of 850 rpm. After being kept warm for 25 minutes, the mixed solution was further heated to 75°C at a heating rate of 0.6°C / min and stirred at a speed of 450 rpm. The mixture was kept warm for 55 minutes to complete aging. The mixture was then centrifuged, washed, and dried to obtain modified zinc oxide.

[0159] (3) tea polyphenol powder, modified zinc oxide, chitosan quaternary ammonium salt, zinc glycyrrhizate, waterborne polyurethane (solid content of 45%) and deionized water were mixed to obtain a functional slurry, wherein the mass fraction of tea polyphenol powder in the functional slurry was 12 wt%, the mass fraction of modified zinc oxide was 7.2 wt%, the mass fraction of chitosan quaternary ammonium salt was 5.7 wt%, the mass fraction of zinc glycyrrhizate was 3.2 wt%, and the mass fraction of waterborne polyurethane was 3.1 wt%;

[0160] The weight is 25g / m 2 The non-woven fabric was immersed in the functional slurry at 35°C for 35 seconds, then taken out and pressed at a pressure of 0.25 MPa for 2.5 seconds, repeated three times, and then dried with hot air at 60°C at a wind speed of 11 m / s for 4 minutes to obtain a functional layer;

[0161] (4) melt-blown PP cloth (weight 26g / m 2 ), functional layer and cotton spunlace fabric (weight 32g / m 2 ) are stacked in sequence, pre-pressed at a pressure of 0.6 MPa and a temperature of 74°C for 25 seconds, and then pressed at a pressure of 3 MPa and a temperature of 110°C for 85 seconds, and the tea polyphenols non-woven mask is obtained after cooling.

[0162] Example 6

[0163] This embodiment provides a method for preparing a tea polyphenol non-woven mask based on ultrafine grinding technology. The difference from Example 1 is that the mass ratio of nano zinc oxide in the zinc oxide dispersion to ethyl orthosilicate in the precursor solution is adjusted to 1:0.3, and the other process parameters and operating steps are exactly the same as those in Example 1.

[0164] Example 7

[0165] This embodiment provides a method for preparing a tea polyphenol non-woven mask based on ultrafine grinding technology. The difference from Example 1 is that the mass ratio of nano zinc oxide in the zinc oxide dispersion to ethyl orthosilicate in the precursor solution is adjusted to 1:0.5, and the other process parameters and operating steps are exactly the same as those in Example 1.

[0166] Example 8

[0167] This embodiment provides a method for preparing a tea polyphenol non-woven mask based on ultrafine grinding technology. The difference from Example 1 is that the mass fraction of tea polyphenol powder in the functional slurry is adjusted to 8wt%, and the other process parameters and operating steps are exactly the same as those in Example 1.

[0168] Example 9

[0169] This embodiment provides a method for preparing a tea polyphenol non-woven mask based on ultrafine grinding technology. The difference from Example 1 is that the mass fraction of tea polyphenol powder in the functional slurry is adjusted to 15wt%, and the other process parameters and operating steps are exactly the same as those in Example 1.

[0170] Example 10

[0171] This embodiment provides a method for preparing a tea polyphenol non-woven mask based on ultrafine grinding technology. The difference from Example 1 is that the mass fraction of modified zinc oxide in the functional slurry is adjusted to 5wt%, and the other process parameters and operating steps are exactly the same as those in Example 1.

[0172] Example 11

[0173] This embodiment provides a method for preparing a tea polyphenol non-woven mask based on ultrafine grinding technology. The difference from Example 1 is that the mass fraction of modified zinc oxide in the functional slurry is adjusted to 10wt%, and the other process parameters and operating steps are exactly the same as those in Example 1.

[0174] Example 12

[0175] This embodiment provides a method for preparing a tea polyphenol non-woven mask based on ultrafine grinding technology. The difference from Example 1 is that the mass fraction of chitosan quaternary ammonium salt in the functional slurry is adjusted to 4wt%, and the other process parameters and operating steps are exactly the same as those in Example 1.

[0176] Example 13

[0177] This embodiment provides a method for preparing a tea polyphenol non-woven mask based on ultrafine grinding technology. The difference from Example 1 is that the mass fraction of chitosan quaternary ammonium salt in the functional slurry is adjusted to 8wt%, and the other process parameters and operating steps are exactly the same as those in Example 1.

[0178] Example 14

[0179] This embodiment provides a method for preparing a tea polyphenol non-woven mask based on ultrafine grinding technology. The difference from Example 1 is that the mass fraction of zinc glycyrrhizate in the functional slurry is adjusted to 2.5wt%, and the other process parameters and operating steps are exactly the same as those in Example 1.

[0180] Example 15

[0181] This embodiment provides a method for preparing a tea polyphenol non-woven mask based on ultrafine grinding technology. The difference from Example 1 is that the mass fraction of zinc glycyrrhizate in the functional slurry is adjusted to 4.5wt%, and the other process parameters and operating steps are exactly the same as those in Example 1.

[0182] The antibacterial rate, air permeability and sensitization rate of the tea polyphenol non-woven masks prepared in Examples 1-15 were tested. The specific testing steps are as follows:

[0183] (1) Antibacterial rate

[0184] The antibacterial rates of the functional layers prepared in Examples 1-15 against Staphylococcus aureus and Escherichia coli were tested with reference to the national standard GB / T 20944.3-2008 “Evaluation of antibacterial properties of textiles Part 3: Oscillation method”.

[0185] (2) Air permeability

[0186] The air permeability of the tea polyphenols non-woven masks prepared in Examples 1-15 was tested with reference to the national standard GB / T 5453-1997 “Determination of Air Permeability of Textile Fabrics”.

[0187] (3) Sensitization rate

[0188] 50 to 200 healthy volunteers (aged 18 to 60 years) were recruited, and those with a history of skin diseases, allergies, or recent use of immunosuppressants were excluded. Before the test, a blank white spot patch (tape + vaseline) was pre-applied to the normal skin on the back to confirm that there was no basic irritation reaction.

[0189] Experimental, control, and positive control groups were set up. In the experimental group, the functional layer of the mask (1×1 cm²) was soaked with saline and placed in a standard patch applicator. The control group received a blank patch applicator containing only saline. The positive control group received a 0.5% dinitrochlorobenzene (DNCB) solution (to test the subject's sensitivity). The patch applicator was applied symmetrically to the subject's upper back and secured with hypoallergenic tape.

[0190] Remove the first application 48 hours after application, leaving a 24-hour rest period (skin rest period). Repeat the application to the same area for a total of 3 cycles (once per week for 3 weeks). 2 to 4 weeks after the last induction, apply the test specimen to an unexposed area (e.g., the contralateral back) for 48 hours.

[0191] Observe 30 minutes, 24 hours, and 48 hours after patch removal and grade according to international standards: Grade 0: no reaction, Grade 1: mild erythema, Grade 2: moderate erythema + edema, Grade 3: severe erythema + edema + papules, and Grade 4: blisters or ulcers. A reaction grade of ≥ Grade 2, with a significantly stronger reaction in the experimental group than in the control group, was considered positive for sensitization.

[0192] The sensitization rate was calculated using the following formula:

[0193] Sensitization rate = (total number of effective subjects / number of positive reactions) × 100%.

[0194] The test results are shown in Table 1.

[0195] Table 1

[0196]

[0197]

[0198] The test data of Examples 1, 6, and 7 show that when the mass ratio of nano-zinc oxide to ethyl orthosilicate is reduced to 1:0.3 (Example 6), the silica coating is incomplete, resulting in a sudden release of zinc ions, the antibacterial rate drops to 87.6%, and the local zinc ion concentration exceeds the standard, with the sensitization rate rising to 8.2%. When the mass ratio of nano-zinc oxide to ethyl orthosilicate is increased to 1:0.5 (Example 7), the excess silicon dioxide aggregates to form colloid particles that block the fiber pores, the air permeability drops to 152.3 mm / s, and the slow release of zinc ions is hindered, resulting in an antibacterial rate of only 92.8%.

[0199] The test data from Examples 1, 8, and 9 show that when the concentration of tea polyphenols powder was reduced to 8 wt% (Example 8), the active ingredient loading was insufficient and unevenly distributed, resulting in an antibacterial rate of only 85.3%. When the concentration of tea polyphenols powder was increased to 15 wt% (Example 9), the slurry viscosity increased, surface oxidation and agglomeration blocked the micropores, and the air permeability dropped to 141.8 mm / s. Furthermore, the excess tea polyphenols reacted with zinc oxide to form an antagonist, causing the sensitization rate to rise to 9.6%.

[0200] The test data of Examples 1, 10, and 11 show that when the concentration of modified zinc oxide is reduced to 5 wt% (Example 10), the zinc ion release is below the antibacterial threshold, and the antibacterial rate is only 88.9%. When the concentration of modified zinc oxide is increased to 10 wt% (Example 11), the coating layer ruptures due to particle accumulation, and the sudden release of zinc ions is too high, resulting in a sensitization rate as high as 12.8%. At the same time, the particles absorb water, resulting in insufficient slurry penetration depth, and the air permeability drops to 168.2 mm / s.

[0201] As can be seen from the test data of embodiment 1, embodiment 12 and embodiment 13, when the concentration of chitosan quaternary ammonium salt was reduced to 4wt% (embodiment 12), the positive charge density deficiency caused the virus capture efficiency to reduce, and the antibacterial rate was only 82.4%. When the concentration of chitosan quaternary ammonium salt was increased to 8wt% (embodiment 13), because of crystallization, the fiber structure was destroyed, and air permeability was reduced to 176.9mm / s, and high concentration quaternary ammonium salt destroyed the skin microecology, and the sensitization rate was increased to 15.4%.

[0202] The test data of Examples 1, 14, and 15 show that when the concentration of zinc glycyrrhizate was reduced to 2.5 wt% (Example 14), insufficient chelating capacity resulted in local excess zinc ions, and the sensitization rate rose to 11.3%. When the concentration of zinc glycyrrhizate was increased to 4.5 wt% (Example 15), a micellar layer formed, blocking the pores, and the air permeability dropped to 183.5 mm / s. Furthermore, due to competitive binding to the phenolic hydroxyl groups of tea polyphenols, the antibacterial rate dropped to 89.8%.

[0203] 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 tea polyphenols non-woven mask based on ultrafine grinding technology, characterized in that: The tea polyphenols non-woven mask comprises a waterproof layer, a functional layer and a skin-friendly layer stacked in sequence; The functional layer is obtained by dipping a non-woven fabric into a functional slurry and then taking it out and drying it. The functional slurry consists of tea polyphenol powder, the modified zinc oxide, chitosan quaternary ammonium salt, zinc glycyrrhizate, a binder and deionized water. The tea polyphenol powder is obtained by ultrafine grinding tea polyphenol, and the modified zinc oxide is obtained by in-situ coating and modifying nano zinc oxide with silicon dioxide.

2. The tea polyphenols non-woven mask according to claim 1, characterized in that: The waterproof layer is melt-blown PP cloth; The meltblown PP cloth has a gram weight of 24 to 26 g / m 2 ; The skin-friendly layer is a cotton spunlace fabric; The gram weight of the cotton spunlace fabric is 28-32 g / m 2 ; The non-woven fabric has a gram weight of 23 to 25 g / m 2 .

3. A method for preparing a tea polyphenols non-woven mask based on ultrafine grinding technology according to claim 1 or 2, characterized in that: The preparation method comprises: (I) Under an inert atmosphere, ultrafinely grinding tea polyphenols and then sieving to obtain tea polyphenol powder; (II) dispersing nano zinc oxide in anhydrous ethanol to obtain a zinc oxide dispersion, adding dropwise a precursor solution consisting of ethyl orthosilicate, 3-aminopropyltriethoxysilane, and an ethanol aqueous solution, followed by aging, and finally centrifuging, washing, and drying to obtain a modified zinc oxide; (III) mixing the tea polyphenol powder, the modified zinc oxide, chitosan quaternary ammonium salt, zinc glycyrrhizate, a binder, and deionized water to obtain a functional slurry, immersing the non-woven fabric in the functional slurry and then taking it out and pressing it, repeating this process at least twice, and drying to obtain a functional layer; (IV) laminating the waterproof layer, the functional layer and the skin-friendly layer in sequence and then hot-pressing them to obtain the tea polyphenols non-woven fabric mask.

4. The preparation method according to claim 3, characterized in that In step (I), the ultrafine grinding is carried out in an ultrafine grinding device, and the rotation speed of the classifying wheel of the ultrafine grinding device is 3400-3600 rpm; The feed pressure of the ultrafine grinding is 0.8-1 MPa; The particle size D50 of the tea polyphenol powder is 2 to 3 μm.

5. The preparation method according to claim 3, characterized in that In step (II), the mass fraction of nano zinc oxide in the zinc oxide dispersion is 7.5-8.5 wt %; The precursor solution is prepared by the following method: preparing an ethanol aqueous solution, adding a hydrochloric acid solution dropwise to the ethanol aqueous solution to adjust the pH value thereof to 3, then adding ethyl orthosilicate and 3-aminopropyltriethoxysilane, mixing and stirring to obtain the precursor solution; The volume ratio of ethanol to deionized water in the ethanol aqueous solution is (3.5-4.5):1; The concentration of the hydrochloric acid solution is 0.04-0.06 mol / L; The molar ratio of the ethyl orthosilicate to the 3-aminopropyltriethoxysilane is (3.5-4.5):1; The mass fraction of ethyl orthosilicate in the precursor solution is 26-28 wt %; The mixing and stirring time is 25 to 35 minutes.

6. The preparation method according to claim 3, characterized in that In step (II), the precursor solution is added at a rate of 0.8 to 1 mL / min; During the dripping process of the precursor solution, heating and stirring the zinc oxide dispersion; The heating temperature of the zinc oxide dispersion is 50-60°C; The stirring speed of the zinc oxide dispersion is 750-850 rpm; The mass ratio of the nano zinc oxide in the zinc oxide dispersion to the ethyl orthosilicate in the precursor solution is 1:(0.35-0.45).

7. The preparation method according to claim 3, characterized in that In step (II), the aging process includes: After all the precursor solutions are dripped in, a mixed solution is obtained, the mixed solution is heated to a first temperature at a first heating rate and stirred at a first speed, kept warm for a period of time, and then continued to be heated to a second temperature at a second heating rate and stirred at a second speed, kept warm for a period of time, to complete aging; The first heating rate is 0.8-1.2°C / min; The first temperature is 63-65°C; The first rotation speed is 750-850 rpm; Keeping the temperature at the first temperature for 25 to 35 minutes; The second heating rate is 0.4-0.6°C / min; The second temperature is 73-75°C; The second speed is 350-450 rpm; Keep at the second temperature for 55 to 65 minutes.

8. The preparation method according to claim 3, characterized in that In step (III), the mass fraction of tea polyphenol powder in the functional slurry is 11-12 wt%; The mass fraction of modified zinc oxide in the functional slurry is 7-8wt%; The mass fraction of chitosan quaternary ammonium salt in the functional slurry is 5.5-6wt%; The mass fraction of zinc glycyrrhizate in the functional slurry is 3.2-3.8 wt %; The mass fraction of the binder in the functional slurry is 2.8 to 3.2 wt%; The adhesive is water-based polyurethane, and the solid content of the water-based polyurethane is 35-45%.

9. The preparation method according to claim 3, characterized in that In step (III), the single immersion time of the non-woven fabric is 35 to 45 seconds; The impregnation temperature of the nonwoven fabric is 25 to 35°C; The pressure of a single pressing of the nonwoven fabric is 0.15 to 0.25 MPa; The single pressing time of the non-woven fabric is 2.5 to 3.5 seconds; The drying method is hot air drying; The hot air drying temperature is 50-60°C; The wind speed of the hot air drying is 11-13 m / s; The hot air drying time is 4 to 6 minutes.

10. The preparation method according to claim 3, characterized in that In step (IV), the waterproof layer is a melt-blown PP cloth; The skin-friendly layer is a cotton spunlace fabric; The hot pressing process includes a pre-pressing stage and a pressing stage which are carried out in sequence; The pressure in the pre-pressing stage is 0.4-0.6 MPa; The temperature in the pre-pressing stage is 74-76°C; The holding time of the pre-pressing stage is 25 to 35 seconds; The pressure in the pressing stage is 2.5-3 MPa; The temperature of the pressing stage is 110-120°C; The holding time of the pressing stage is 85 to 95 seconds.

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