A hydrophilic, air-permeable nonwoven fabric and a method for producing the same

Abstract

The application discloses a kind of hydrophilic breathable non-woven fabrics and preparation method thereof, it is related to non-woven fabric preparation technical field, and preparation method includes the following steps: polypropylene chip is heated, melt extrusion, sent into spinneret, and polypropylene fiber is obtained by hot air drafting then is soaked in modified liquid, is taken out and dried after using ultraviolet irradiation machine to carry out irradiation, and modified polypropylene fiber is obtained;Take modified polypropylene fiber, polylactic acid fiber, and are opened, mixed carding, stack into fiber web, drafting, uniform, water jet, and obtain non-woven fabric base cloth, on the surface of base cloth spray treatment liquid, once dry, then base cloth is immersed into antibacterial liquid, impregnation, padding, secondary drying, and the hydrophilic breathable non-woven fabric is obtained;Prepared non-woven fabric base cloth has excellent water absorption and air permeability, after treatment liquid spraying and antibacterial liquid impregnation, the hydrophilic breathable non-woven fabric with long-acting antibacterial capacity is obtained.

Description

Technical Field

[0001] This invention relates to the field of nonwoven fabric preparation technology, specifically to a hydrophilic and breathable nonwoven fabric and its preparation method. Background Technology

[0002] Nonwoven fabric, also known as non-woven textile, is a fabric-like material formed by bonding fibers through mechanical or thermal methods. Compared with traditional spinning and weaving processes, nonwoven fabric has advantages such as low cost, wide availability, short process flow, and high production efficiency. Depending on the production process, nonwoven fabric can be divided into meltblown nonwoven fabric, needle-punched nonwoven fabric, wet-laid nonwoven fabric, spunbond nonwoven fabric, and thermally bonded nonwoven fabric. To meet the needs of different applications, the fiber materials used in nonwoven fabric production mainly include polyester (polyethylene terephthalate, PET), polypropylene (polypropylene, PP), nylon (polyamide, PA), chlorofiber (polyvinyl chloride, PVC), acrylic fiber (polyacrylonitrile, PAN), and spandex (polyurethane, PU). Among these, polypropylene nonwoven fabric is widely used in medical and health fields, clothing fabrics, industrial substrates, packaging materials, and filter materials due to its advantages such as low price, lightweight and moisture-proof properties, good physical and chemical stability, good air permeability, good corrosion resistance, and environmental friendliness.

[0003] Polypropylene nonwoven fabric is a nonwoven fabric formed by polymerizing propylene monomers, melt spinning, and randomly overlapping fibers into a network. Its structure contains a large number of methyl groups, lacks reactive sites, and exhibits high crystallinity and low free energy. The lack of functional groups and the compact surface structure result in poor hydrophilicity of polypropylene nonwoven fabric, a defect that greatly limits its further application as a functional material. With the rapid development of my country's industry, polypropylene nonwoven fabric, as a new type of environmentally friendly material, will undoubtedly have a wider range of applications, making surface functionalization modification particularly important.

[0004] (1) Physical modification: Surface coating modification involves immersing polypropylene nonwoven fabric in water-soluble polymers, amphiphilic polymers, surfactants, or other hydrophilic modifiers, or spraying the modifier onto the surface of the nonwoven fabric. After a period of time, the polymer with hydrophilic groups will adhere to the surface of the nonwoven fabric, thereby improving its hydrophilicity. Surface coating modification is a common method for modifying the hydrophilicity of functional materials due to its short processing time, simple operation, low cost, and obvious effect. However, the modification is time-sensitive because the interaction between the coating layer and the surface of the nonwoven fabric is relatively weak. Once the coating layer falls off, the modification effect will gradually disappear. Selecting a hydrophilic modifier with uniform coating and good stability is the key to the application of surface coating method.

[0005] (2) Chemical modification: Plasma treatment can generate polar oxygen-containing groups such as hydroxyl and carboxyl groups on the surface of nonwoven fabric, thereby improving the hydrophilicity of the nonwoven fabric surface. However, the structure of the nonwoven fabric itself is easily damaged during the modification process.

[0006] Chinese patent document CN202310879798.0 discloses a method for preparing a hydrophilic bicomponent nonwoven fabric, belonging to the field of nonwoven fabric technology. The preparation method includes preparing a hydrophilic masterbatch, preparing a first layer of parallel bicomponent fiber web, preparing a second layer of parallel bicomponent fiber web, preparing a third layer of parallel bicomponent fiber web, thermally bonding, and post-processing. The preparation of the hydrophilic masterbatch involves mixing isotactic polypropylene, thermoplastic aerogel, ethylene-acrylic acid copolymer, sodium ethyl acetoacetate, and polypropylene glycol 2000 in a weight ratio of 38-42:12-15:15-18:5-8:10-15, then adding the mixture to a twin-screw extruder for extrusion, granulation, melting, and pelletizing to obtain the hydrophilic masterbatch. The prepared hydrophilic bicomponent nonwoven fabric has high strength, fast water permeability, and is not prone to pilling or fuzzing due to friction, while also exhibiting good durability, softness, and air permeability.

[0007] Existing polypropylene nonwoven fabrics have poor hydrophilicity, cannot effectively and quickly absorb liquids, and have poor sustained antibacterial ability, which easily leads to bacterial growth. Summary of the Invention

[0008] In order to overcome the shortcomings of the existing technology, the purpose of this invention is to provide a hydrophilic and breathable nonwoven fabric and its preparation method. The prepared nonwoven fabric base has excellent water absorption and breathability. After being sprayed with a treatment liquid and impregnated with an antibacterial liquid, a hydrophilic and breathable nonwoven fabric with long-lasting antibacterial ability can be obtained.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A method for preparing a hydrophilic and breathable nonwoven fabric includes the following steps: taking modified polypropylene fiber and polylactic acid fiber, opening, mixing and combing, stacking into a fiber web, stretching, leveling, and hydroentangling to obtain a nonwoven base fabric, spraying a treatment liquid onto the surface of the base fabric, drying it once, then immersing the base fabric in an antibacterial liquid, impregnating, rolling, and drying it a second time to obtain the hydrophilic and breathable nonwoven fabric.

[0011] Preferably, the spraying pressure is 0.5-0.8 MPa, the spraying distance is 10-20 cm, and the drying conditions are 60-80℃ for 3-8 min.

[0012] Preferably, the solution is soaked for 5 to 15 minutes at a liquor ratio of 1:10 to 1:20, then rolled under a pressure of 0.15 to 0.3 MPa, and then dried at 60 to 100°C for 5 to 15 minutes.

[0013] Preferably, the method for preparing the modified polypropylene fiber includes the following steps: feeding polypropylene chips into a screw extruder, heating them into a melt, extruding the melted material, uniformly feeding it into a spinneret, and stretching it with hot air to obtain polypropylene fibers; immersing the polypropylene fibers in a modification liquid, then removing and drying them, and irradiating the polypropylene fibers with an ultraviolet irradiator to obtain modified polypropylene fibers.

[0014] Preferably, the MFR range of the polypropylene chips is 1300–1800 g / 10 min; the spinneret shape is four-lobed, and the hot air volume is 4000–4200 m³ / min. 3 / h, hot air temperature is 230~250℃, fiber diameter is 0.5~1μm.

[0015] Preferably, the modified solution is an ethanol solution of 3-6 wt% acetone and 3-6 wt% toluene, with a soaking time of 20-40 min, drying conditions of drying at 60-70°C for 2-3 h, and ultraviolet irradiation time of 30-60 min.

[0016] Preferably, the method for preparing the treatment solution includes the following steps:

[0017] Chloropropyltrimethoxysilane, phenothiazine, palladium acetate, and sodium tert-butoxide were added to a reaction vessel, followed by toluene and tri-tert-butylphosphine. Nitrogen gas was continuously introduced and the reaction was stirred. The reaction solution was extracted with ethyl acetate, washed with deionized water, and the organic layer was collected. The organic solvent was removed by rotary evaporation, and solid compound a was finally obtained. Compound a was dispersed in anhydrous ethanol and stirred evenly to obtain a treatment solution.

[0018] The structural formula of compound a is:

[0019]

[0020] Preferably, the molar ratio of chloropropyltrimethoxysilane, phenothiazine, palladium acetate, sodium tert-butoxide, and tri-tert-butylphosphine is 1–1.1:1:0.005–0.02:1.4–1.6:0.01–0.03, the reaction concentration of phenothiazine is 0.05–0.1 mol / L, the reaction conditions are 100–120 °C for 8–14 h, the volume ratio of the reaction solution to ethyl acetate is 1:2–4, and the weight ratio of compound a to anhydrous ethanol is 0.5–5:60–80.

[0021] Preferably, the method for preparing the antibacterial solution includes the following steps: adding silver nitrate and copper nitrate to an aqueous solution of carboxymethyl chitosan, adjusting the pH, and ultrasonically vibrating to obtain the antibacterial solution; the molar ratio of silver nitrate, copper nitrate, and carboxymethyl chitosan is 1-3:1:5-8, and the concentration of silver nitrate in the antibacterial solution is 0.5-1.5 wt%; adjusting the pH to 5-7, and ultrasonically vibrating for 0.5-1.5 h.

[0022] Preferably, the weight ratio of modified polypropylene fiber to polylactic acid fiber is 75-85:15-45.

[0023] The present invention also claims a hydrophilic and breathable nonwoven fabric prepared using the aforementioned preparation method.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1) This invention provides a hydrophilic and breathable nonwoven fabric. Polypropylene fibers with a four-lobed cross-section are obtained by hot air stretching, which has a large surface area and can effectively improve the air permeability and moisture permeability of the fibers. Then, the polypropylene fibers are modified by ultraviolet irradiation, which causes the polypropylene fiber surface to generate broken bonds under the influence of high-energy radiation and roughens its surface morphology, thereby improving the hydrophilicity of the polypropylene fibers. Meanwhile, polylactic acid fibers have good comfort, good breathability, and are soft and skin-friendly, which can improve the comfort and breathability of the nonwoven fabric. The prepared nonwoven fabric base has excellent water absorption and breathability. After being sprayed with a treatment liquid and impregnated with an antibacterial liquid, a hydrophilic and breathable nonwoven fabric with long-lasting antibacterial ability can be obtained.

[0026] 2) This invention provides a treatment solution. Compound a is obtained by grafting halogen atoms from chloropropyltrimethoxysilane onto phenothiazine via a reaction between halogen atoms and secondary amines from phenothiazine. This compound is then dispersed in anhydrous ethanol to prepare the treatment solution. The siloxane bonds in compound a can undergo hydrolytic cross-linking with the hydroxyl groups on the surface of the nonwoven fabric fibers, fixing the phenothiazine onto the nonwoven fabric surface through chemical bonds. Subsequently, the nonwoven fabric is immersed in the antibacterial solution and subjected to ultrasonic vibration. The sulfur atoms in the phenothiazine can form high-energy S-Ag and S-Cu bonds with nano-silver and nano-copper particles, significantly improving the adhesion between the silver and copper particles and the nonwoven fabric, thereby achieving a long-lasting antibacterial effect. Furthermore, phenothiazine has two benzene ring groups, which impart strong lipid solubility, allowing it to fully miscible with cell membranes and synergistically enhance the sterilization activity of silver and copper. However, excessive addition of phenothiazine will reduce the hydrophilicity of the fibers; therefore, the concentration of compound a in the treatment solution should not be too high. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. Of course, the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention.

[0028] Unless otherwise specified, all chemical reagents and materials in this invention are purchased from the market or synthesized from raw materials purchased from the market.

[0029] A method for preparing a hydrophilic and breathable nonwoven fabric includes the following steps:

[0030] (1) Polypropylene chips (MFR range of 1300-1800 g / 10 min) are fed into a screw extruder, heated to become a melt, and the material is molten and extruded, then evenly fed into a spinneret with a four-lobed spinneret orifice, through an air volume of 4000-4200 m³ / min. 3 Hot air drawing at 230–250°C for 1 hour yields polypropylene fibers with a diameter of 0.5–1 μm. The polypropylene fibers are then immersed in a modifying solution (3–6 wt% acetone and 3–6 wt% toluene in ethanol) for 20–40 minutes, then removed and dried at 60–70°C for 2–3 hours. Finally, the polypropylene fibers are irradiated with ultraviolet light for 30–60 minutes to obtain modified polypropylene fibers.

[0031] (2) Add 0.1-0.11 mol of chloropropyltrimethoxysilane, 0.1 mol of phenothiazine, 0.0005-0.002 mol of palladium acetate, and 0.14-0.16 mol of sodium tert-butoxide to a reaction vessel, then add 2 L of toluene and 0.001-0.003 mol of tritert-butylphosphine. Continuously purge with nitrogen gas and stir the reaction at 100-120 °C for 8-14 h. Extract the reaction solution with ethyl acetate, then wash with deionized water, collect the organic layer, and remove the organic solvent by rotary evaporation to finally obtain solid compound a. Disperse 0.5-5 g of compound a in 60-80 g of anhydrous ethanol and stir until homogeneous to obtain the treated solution.

[0032] (3) Add 0.1-0.3 mol silver nitrate and 0.1 mol copper nitrate to 0.5-0.8 mol carboxymethyl chitosan aqueous solution, adjust the pH to 5-7, and sonicate for 0.5-1.5 h to obtain antibacterial solution (the concentration of silver nitrate in the antibacterial solution is 0.5-1.5 wt%).

[0033] (4) Take 75-85g of modified polypropylene fiber and 15-45g of polylactic acid fiber, open, mix and comb, stack into fiber web, stretch, level and hydroentangle to obtain nonwoven base fabric. Spray treatment liquid on the surface of the base fabric at a spraying pressure of 0.5-0.8MPa and a spraying distance of 10-20cm. Dry at 60-80℃ for 3-8min. Then immerse the base fabric in antibacterial liquid at a bath ratio of 1:10-1:20 for 5-15min. Then roll the liquid under a pressure of 0.15-0.3MPa and dry at 60-100℃ for 5-15min to obtain the hydrophilic and breathable nonwoven fabric.

[0034] The present invention will be further described below through specific embodiments.

[0035] Example 1

[0036] A method for preparing a hydrophilic and breathable nonwoven fabric includes the following steps:

[0037] (1) Polypropylene chips are fed into a screw extruder, heated to become a melt, and the material is molten and extruded, then evenly fed into a spinneret with a four-lobed spinneret nozzle, through which an air volume of 4200 m³ / h is passed. 3 Hot air stretching at 250℃ for 1 hour yields polypropylene fibers with a diameter of 1 μm. The polypropylene fibers are then immersed in a modification solution (6 wt% acetone and 6 wt% toluene in ethanol) for 40 minutes, then dried at 70℃ for 3 hours, and irradiated with ultraviolet light for 60 minutes to obtain modified polypropylene fibers.

[0038] (2) 0.11 mol of chloropropyltrimethoxysilane, 0.1 mol of phenothiazine, 0.002 mol of palladium acetate, and 0.16 mol of sodium tert-butoxide were added to a reaction vessel, followed by 2 L of toluene and 0.003 mol of tritert-butylphosphine. Nitrogen gas was continuously introduced, and the mixture was stirred at 120 °C for 14 h. The reaction solution was extracted with ethyl acetate and then washed with deionized water. The organic layer was collected, and the organic solvent was removed by rotary evaporation to obtain solid compound a. 5 g of compound a was dispersed in 80 g of anhydrous ethanol and stirred until homogeneous to obtain the treatment solution.

[0039] (3) Add 0.3 mol silver nitrate and 0.1 mol copper nitrate to 0.8 mol carboxymethyl chitosan aqueous solution, adjust the pH to 6, and sonicate for 1 h to obtain antibacterial solution (the concentration of silver nitrate in the antibacterial solution is 1 wt%).

[0040] (4) Take 80g of modified polypropylene fiber and 30g of polylactic acid fiber, open, mix and comb, stack into fiber web, stretch, level and hydroentangle to obtain nonwoven base fabric, spray treatment liquid on the surface of base fabric at a spraying pressure of 0.6MPa and a spraying distance of 15cm, dry at 70℃ for 5min, then immerse the base fabric in antibacterial liquid at a bath ratio of 1:15 for 10min, then roll the liquid under a pressure of 0.2MPa and dry at 80℃ for 10min to obtain the hydrophilic and breathable nonwoven fabric.

[0041] Example 2

[0042] A method for preparing a hydrophilic and breathable nonwoven fabric includes the following steps:

[0043] (1) Polypropylene chips are fed into a screw extruder, heated to become a melt, and the material is molten and extruded, then evenly fed into a spinneret with a four-lobed spinneret nozzle, through which an air volume of 4100 m³ / s is passed. 3Hot air stretching at 240℃ for 1 hour yielded polypropylene fibers with a diameter of 0.8 μm. The polypropylene fibers were then immersed in a modification solution (5 wt% acetone and 5 wt% toluene in ethanol) for 30 min, then dried at 65℃ for 2.5 h, and irradiated with ultraviolet light for 45 min to obtain modified polypropylene fibers.

[0044] (2) 0.105 mol of chloropropyltrimethoxysilane, 0.1 mol of phenothiazine, 0.001 mol of palladium acetate, and 0.15 mol of sodium tert-butoxide were added to a reaction vessel, followed by 2 L of toluene and 0.002 mol of tritert-butylphosphine. Nitrogen gas was continuously introduced, and the mixture was stirred at 110 °C for 10 h. The reaction solution was extracted with ethyl acetate and then washed with deionized water. The organic layer was collected, and the organic solvent was removed by rotary evaporation to obtain solid compound a. 3 g of compound a was dispersed in 70 g of anhydrous ethanol and stirred until homogeneous to obtain the treatment solution.

[0045] (3) Add 0.2 mol silver nitrate and 0.1 mol copper nitrate to 0.6 mol carboxymethyl chitosan aqueous solution, adjust pH to 6, and sonicate for 1 h to obtain antibacterial solution (the concentration of silver nitrate in the antibacterial solution is 1 wt%).

[0046] (4) Take 80g of modified polypropylene fiber and 30g of polylactic acid fiber, open, mix and comb, stack into fiber web, stretch, level and hydroentangle to obtain nonwoven base fabric, spray treatment liquid on the surface of base fabric at a spraying pressure of 0.6MPa and a spraying distance of 15cm, dry at 70℃ for 5min, then immerse the base fabric in antibacterial liquid at a bath ratio of 1:15 for 10min, then roll the liquid under a pressure of 0.2MPa and dry at 80℃ for 10min to obtain the hydrophilic and breathable nonwoven fabric.

[0047] Example 3

[0048] A method for preparing a hydrophilic and breathable nonwoven fabric includes the following steps:

[0049] (1) Polypropylene chips are fed into a screw extruder, heated to become a melt, and the material is molten and extruded, then evenly fed into a spinneret with four-lobed spinneret orifices, through an air volume of 4000 m³ / h. 3 Hot air stretching at 230℃ for 2 hours yielded polypropylene fibers with a diameter of 0.5μm; the polypropylene fibers were then immersed in a modification solution (3wt% acetone and 3wt% toluene in ethanol) for 20 minutes, then dried at 60℃ for 2 hours, and irradiated with ultraviolet light for 30 minutes to obtain modified polypropylene fibers.

[0050] (2) 0.1 mol of chloropropyltrimethoxysilane, 0.1 mol of phenothiazine, 0.0005 mol of palladium acetate, and 0.14 mol of sodium tert-butoxide were added to a reaction vessel, followed by 2 L of toluene and 0.001 mol of tritert-butylphosphine. Nitrogen gas was continuously introduced, and the mixture was stirred at 100 °C for 8 h. The reaction solution was extracted with ethyl acetate and then washed with deionized water. The organic layer was collected, and the organic solvent was removed by rotary evaporation to obtain solid compound a. 0.5 g of compound a was dispersed in 60 g of anhydrous ethanol and stirred until homogeneous to obtain the treatment solution.

[0051] (3) Add 0.1 mol silver nitrate and 0.1 mol copper nitrate to 0.5 mol carboxymethyl chitosan aqueous solution, adjust the pH to 6, and sonicate for 1 h to obtain antibacterial solution (the concentration of silver nitrate in the antibacterial solution is 1 wt%).

[0052] (4) Take 80g of modified polypropylene fiber and 30g of polylactic acid fiber, open, mix and comb, stack into fiber web, stretch, level and hydroentangle to obtain nonwoven base fabric, spray treatment liquid on the surface of base fabric at a spraying pressure of 0.6MPa and a spraying distance of 15cm, dry at 70℃ for 5min, then immerse the base fabric in antibacterial liquid at a bath ratio of 1:15 for 10min, then roll the liquid under a pressure of 0.2MPa and dry at 80℃ for 10min to obtain the hydrophilic and breathable nonwoven fabric.

[0053] Comparative Example 1

[0054] A method for preparing a nonwoven fabric includes the following steps:

[0055] (1) 0.11 mol of chloropropyltrimethoxysilane, 0.1 mol of phenothiazine, 0.002 mol of palladium acetate and 0.16 mol of sodium tert-butoxide were added to a reaction vessel, followed by 2 L of toluene and 0.003 mol of tritert-butylphosphine. Nitrogen gas was continuously introduced, and the mixture was stirred at 120 °C for 14 h. The reaction solution was extracted with ethyl acetate and then washed with deionized water. The organic layer was collected, and the organic solvent was removed by rotary evaporation to obtain solid compound a. 5 g of compound a was dispersed in 80 g of anhydrous ethanol and stirred evenly to obtain the treatment solution.

[0056] (2) Take 80g of polypropylene fiber and 30g of polylactic acid fiber, open, mix and comb, stack into fiber web, stretch, level and hydroentangle to obtain nonwoven base fabric, spray treatment liquid on the surface of base fabric, spray pressure is 0.6MPa, spray distance is 15cm, dry at 70℃ for 5min to obtain the nonwoven fabric.

[0057] Comparative Example 2

[0058] A method for preparing a nonwoven fabric includes the following steps:

[0059] (1) Add 0.3 mol silver nitrate and 0.1 mol copper nitrate to 0.8 mol carboxymethyl chitosan aqueous solution, adjust the pH to 6, and sonicate for 1 h to obtain antibacterial solution (the concentration of silver nitrate in the antibacterial solution is 1 wt%).

[0060] (2) Take 80g of polypropylene fiber and 30g of polylactic acid fiber, open, mix and comb, stack into fiber web, stretch, level and hydroentangle to obtain nonwoven base fabric, immerse the base fabric in antibacterial solution, soak for 10min at a bath ratio of 1:15, then roll the solution under 0.2MPa pressure and dry at 80℃ for 10min to obtain the nonwoven fabric.

[0061] Performance tests were conducted on the nonwoven fabrics prepared in Examples 1-3 and Comparative Examples 1-2. Referring to ZB W 04019-1990 "Textiles - Capillary Effect Test Methods," the 60-second water absorption height (moisture wicking) was measured using a YG871 capillary effect measuring instrument. The test fabric sample size was 25mm × 300mm. Moisture wicking reflects the instantaneous absorption of the surface layer; the higher the value, the better the instantaneous absorption. Air permeability was tested according to GB / T24218.15-2018 "Textiles - Nonwoven Fabrics - Test Methods - Part 15: Determination of Air Permeability." Moisture permeability was tested according to GB / T 12704.2-2009 "Textiles - Fabrics - Test Methods - Moisture Permeability - Part 2: Evaporation Method." Initial antibacterial activity and antibacterial activity after 50 washes were tested according to GB15979-2002 "Hygienic Standard for Disposable Sanitary Products." Five parallel groups were used, and the average value was taken. Specific data are shown in Table 1.

[0062] Table 1. Test Results of Nonwoven Fabric Performance

[0063]

[0064] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a hydrophilic and breathable nonwoven fabric, characterized in that, The process includes the following steps: taking modified polypropylene fiber and polylactic acid fiber, opening, mixing and combing, stacking into a fiber web, stretching, leveling, and hydroentangling to obtain a nonwoven base fabric, spraying a treatment liquid on the surface of the base fabric, drying it once, and then immersing the base fabric in an antibacterial liquid, impregnating, squeezing, and drying it a second time to obtain the hydrophilic and breathable nonwoven fabric. The method for preparing the modified polypropylene fiber includes the following steps: feeding polypropylene chips into a screw extruder, heating them into a melt, extruding the melted material, uniformly feeding it into a spinneret, and stretching it with hot air to obtain polypropylene fibers; immersing the polypropylene fibers in a modification liquid, then removing and drying them, and irradiating the polypropylene fibers with an ultraviolet irradiator to obtain modified polypropylene fibers. The modified solution is an ethanol solution of 3-6 wt% acetone and 3-6 wt% toluene, with a soaking time of 20-40 min, drying conditions of drying at 60-70℃ for 2-3 h, and ultraviolet irradiation time of 30-60 min; The method for preparing the treatment solution includes the following steps: Chloropropyltrimethoxysilane, phenothiazine, palladium acetate, and sodium tert-butoxide were added to a reaction vessel, followed by toluene and tri-tert-butylphosphine. Nitrogen gas was continuously introduced and the reaction was stirred. The reaction solution was extracted with ethyl acetate, washed with deionized water, and the organic layer was collected. The organic solvent was removed by rotary evaporation, and solid compound a was finally obtained. Compound a was dispersed in anhydrous ethanol and stirred evenly to obtain a treatment solution. The structural formula of compound a is: 。 2. The preparation method according to claim 1, characterized in that, The spraying pressure is 0.5~0.8MPa, the spraying distance is 10~20cm, and the drying conditions are 60~80℃ for 3~8min.

3. The preparation method according to claim 1, characterized in that, Soak the liquid at a liquor ratio of 1:10 to 1:20 for 5 to 15 minutes, then roll it under a pressure of 0.15 to 0.3 MPa, and dry it at 60 to 100°C for 5 to 15 minutes.

4. The preparation method according to claim 1, characterized in that, The MFR range of the polypropylene chips is 1300~1800g / 10min; the spinneret shape is four-lobed, and the hot air volume is 4000~4200m³. 3 / h, hot air temperature is 230~250℃, fiber diameter is 0.5~1μm.

5. The preparation method according to claim 1, characterized in that, The molar ratio of chloropropyltrimethoxysilane, phenothiazine, palladium acetate, sodium tert-butoxide, and tritert-butylphosphine is 1~1.1:1:0.005~0.02:1.4~1.6:0.01~0.03, and the reaction concentration of phenothiazine is 0.05~0.1 mol / L; the reaction conditions are stirred at 100~120℃ for 8~14 h; the volume ratio of the reaction solution to ethyl acetate is 1:2~4; and the weight ratio of compound a to anhydrous ethanol is 0.5~5:60~80.

6. The preparation method according to claim 1, characterized in that, The method for preparing the antibacterial solution includes the following steps: adding silver nitrate and copper nitrate to a carboxymethyl chitosan aqueous solution, adjusting the pH, and ultrasonically vibrating to obtain the antibacterial solution; the molar ratio of silver nitrate, copper nitrate, and carboxymethyl chitosan is 1~3:1:5~8, and the concentration of silver nitrate in the antibacterial solution is 0.5~1.5wt%; adjusting the pH to 5~7, and ultrasonically vibrating for 0.5~1.5h.

7. A hydrophilic and breathable nonwoven fabric prepared by the preparation method according to any one of claims 1 to 6.

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