Medical and sanitary antibacterial flame-retardant double-effect polypropylene non-woven fabric color master batch and preparation method thereof

Abstract

The invention discloses a medical and sanitary antibacterial flame-retardant double-effect polypropylene non-woven fabric color master batch and a preparation method thereof, and belongs to the technical field of polypropylene non-woven fabric master batches, the preparation method comprises the following steps: preparing a coating pigment, preparing an antibacterial agent, preparing a flame retardant, and granulating; the preparation of the coated pigment comprises the steps of dispersion treatment and coating; in the dispersion treatment, stearic acid is used for carrying out dispersion treatment on the pigment, and the pigment subjected to dispersion treatment is obtained; the coating comprises the following steps: mixing polyvinylpyrrolidone and water, adding the dispersed pigment, stirring, adding an aqueous solution of calcium chloride, stirring, centrifuging, mixing the precipitate and water, stirring, adding an aqueous solution of sodium carbonate, stirring, standing, centrifuging, taking the precipitate, and drying in vacuum; the polypropylene non-woven fabric color master batch prepared by the invention has excellent antibacterial property and flame retardance at the same time, and the prepared non-woven fabric is not easy to break in spinning, and has the advantages of uniform coloring, uniform antibacterial property distribution, high mechanical strength and high elongation at break.

Description

Technical Field

[0001] This invention relates to the field of polypropylene nonwoven fabric masterbatch technology, specifically to a medical and health-grade antibacterial and flame-retardant dual-effect polypropylene nonwoven fabric color masterbatch and its preparation method. Background Technology

[0002] Polypropylene (PP) is a type of polyolefin and one of the most widely used polymers. Due to its suitable processing temperature, excellent mechanical strength, good chemical resistance, and extremely low moisture absorption, one of PP's important applications is as a raw material for nonwoven fabrics. Nonwoven fabrics, also known as non-woven textiles, are fabric-like materials formed by the ordered or disordered arrangement of fibers. They are mainly bonded together by the fibers' own adhesive force, external bonding, or a combination of both. Compared to traditional woven fabrics, nonwoven fabrics have advantages such as lower cost, shorter processing time, and higher production capacity. Depending on the preparation method, nonwoven fabrics are classified into spunbond nonwoven fabrics, meltblown nonwoven fabrics, spunlace nonwoven fabrics, and thermally bonded nonwoven fabrics. Polypropylene nonwoven fabrics have the advantages of low price and stable physical properties, as well as excellent air permeability and corrosion resistance. They are widely used in medical and health fields, filter substrates, and agricultural products. Polypropylene has a broad development prospect in the preparation of nonwoven fabrics, especially in the preparation of spunbond nonwoven fabrics, where more than half of the raw materials currently used are polypropylene.

[0003] Color masterbatch is a high-efficiency and high-concentration resin coloring mixture prepared by processing and dispersing colorants, carrier resins, and additives. Depending on the application, color masterbatch is classified into injection molding masterbatch, blow molding masterbatch, and spinning masterbatch, among others. Spinning masterbatch is used for coloring fibers during spinning; it features fine pigment particles, high concentration, strong coloring power, and good heat and light resistance.

[0004] The colorants used in masterbatches mainly include dyes, inorganic pigments, and organic pigments. Dyes have advantages such as good transparency, high tinting strength, and low density; however, they require high processing temperatures and sufficient residence time to ensure complete dissolution in the polymer. Furthermore, dye molecules are generally very small, leading to migration when used for coloring polyolefins. Therefore, dyes have poor heat resistance and migration resistance. Currently, dyes are mainly used for coloring engineering plastics. Inorganic and organic pigments are insoluble in common solvents and have no affinity for the material being colored. During coloring, they are dispersed in the material as particles. Currently, inorganic and organic pigments are mainly used for coloring polyvinyl chloride (PVC) and polyolefins. Inorganic pigments are mainly natural or synthetic metal oxides, sulfides, salts of lead and cadmium calcined at high temperatures, mercury compounds, etc. Inorganic pigments have good lightfastness and heat resistance, and are inexpensive, but their brightness and transparency are relatively poor, and they are mainly used as black and white pigments. Organic pigments have brighter colors, high tinting strength, good dispersibility, a complete color spectrum, lower density, larger specific surface area, better transparency, and stronger color resolution.

[0005] When polypropylene nonwoven fabrics are used in medical and health applications, the most common use is to produce SMS, SMMS, and SMMMS polypropylene nonwoven fabrics for use as materials for masks, surgical gowns, and surgical drapes. To facilitate observation of gradient distribution, SMS, SMMS, and SMMMS polypropylene nonwoven fabrics often come in different colors; therefore, color masterbatches are frequently added during the preparation of polypropylene nonwoven fabrics. Furthermore, conventional medical-grade polypropylene nonwoven fabrics lack antibacterial and flame-retardant properties. During application, the increased adsorption and retention of pathogens can easily lead to secondary infections among medical personnel. Moreover, due to the poor antistatic properties of polypropylene, it is also prone to combustion. Therefore, antibacterial agents and flame retardants need to be added to the preparation method of polypropylene nonwoven fabrics. To improve the dispersibility of antibacterial and flame retardant agents and shorten processing time, antibacterial and flame retardant agents are often added to color masterbatches to produce antibacterial and flame-retardant dual-effect polypropylene nonwoven fabric color masterbatches.

[0006] Research on the Application of Antibacterial, Flame-Retardant, and Antistatic Polypropylene in the Selection of Antibacterial Agents. Chen Fang. Master's Thesis, Hebei University of Technology. February 2006. Currently commonly used antibacterial agents include inorganic antibacterial agents, organic antibacterial agents, and inorganic-organic composite antibacterial agents. Among them, inorganic antibacterial agents are mostly metal ion-based antibacterial agents, with silver ions, zinc ions, and copper ions being the most common. Silver ions have the strongest antibacterial properties and are the most widely used, but their chemical reactivity makes them easily converted into brown silver oxide or reduced to black elemental silver under ultraviolet light catalysis, thus affecting the coloring properties of the masterbatch. Organic antibacterial agents suffer from poor lightfastness, heat resistance, and durability. Inorganic-organic composite antibacterial agents use layered metal oxides as the matrix and utilize interlayer insertion reactions to insert silver complexes or other organic antibacterial agents into the interlayer spaces. Inorganic-organic composite antibacterial agents exhibit excellent lightfastness, heat resistance, durability, and good antibacterial properties.

[0007] Research on the Selection of Flame Retardants and Their Application in Antibacterial, Flame-Retardant, and Antistatic Polypropylene. Chen Fang. Master's Thesis, Hebei University of Technology. February 2006. Currently, commonly used flame retardants include inorganic and organic flame retardants. Inorganic flame retardants mainly include aluminum hydroxide and magnesium hydroxide. However, because aluminum hydroxide and magnesium hydroxide have different crystal orientations with polypropylene and poor dispersibility in polypropylene, they can affect the mechanical strength of polypropylene. Organic flame retardants mainly include halogenated flame retardants and intumescent flame retardants. Halogenated flame retardants have poor environmental performance, while intumescent flame retardants, composed of a carbon source, acid source, and foaming source, have good flame retardancy and heat resistance.

[0008] In summary, the most common method for preparing antibacterial and flame-retardant dual-effect polypropylene nonwoven masterbatch to obtain masterbatch with good overall performance is to use a wet process to produce masterbatch from organic pigments, polypropylene resin, inorganic-organic composite antibacterial agents, intumescent flame retardants, and other additives. However, the resulting masterbatch has the following problems: First, the influence of inorganic nanofillers on the coloring effect and pigment dispersibility of masterbatches. Huang Yao, Master's Thesis, Beijing University of Chemical Technology, May 2008. This thesis disclosed that due to the small particle size and large specific surface area of ​​pigment particles, they are highly prone to agglomeration into secondary particles, especially for masterbatches used in polypropylene nonwoven fabrics, where the pigment particle size is required to be less than 1μm, making agglomeration even more likely. To address this issue, the thesis further disclosed the influence of inorganic nanofillers on the coloring effect and pigment dispersibility of masterbatches. Commonly used inorganic nanofillers are nano-calcium carbonate and nano-barium sulfate. The thesis also disclosed that chemical surface treatment of pigments with aluminate coupling agents and nano-calcium carbonate improves pigment dispersibility, with the improvement effect being superior to that of direct blending. However, the method of using nano-calcium carbonate for chemical surface treatment of pigments was not disclosed. For nano-calcium carbonate, precipitation is commonly used. The research and application of mineral powder surface nano-modification technology (Fan Shimin, Tsinghua University Doctoral Dissertation, April 2004) revealed that precipitation methods suffer from difficulties in process control and uneven coating layers. Therefore, using nano-calcium carbonate for pigment surface treatment may lead to uneven pigment particle size. Furthermore, this can cause filament breakage during spinning after adding masterbatch to the preparation of polypropylene nonwoven fabric, and also result in uneven coloring of the prepared polypropylene nonwoven fabric.

[0009] Secondly, for inorganic-organic composite antibacterial agents used in polypropylene nonwoven fabrics, in order to avoid filament breakage during spinning, it is also necessary to control the particle size of the layered metal oxides used in the preparation of inorganic-organic composite antibacterial agents. However, if the particle size is too small, agglomeration problems are likely to occur during the preparation of inorganic-organic composite antibacterial agents, resulting in uneven intercalation. Furthermore, this leads to uneven distribution of antibacterial properties after application in polypropylene nonwoven fabrics.

[0010] Third, the influence of silane coupling agents on the water resistance and mechanical properties of intumescent flame-retardant polypropylene. Wang Yuchen, Zhong Zhiqiang, Gong Xiaodi. *Fine Chemicals & Modern Chemical Research*, January 2025. Intumescent flame retardants have received increasing attention in recent years due to their advantages such as anti-drip properties, low smoke emissions, and low release of toxic gases during combustion. However, polypropylene is a non-polar polymer, while intumescent flame retardants contain ammonium salts, which have a high polarity. The large difference in polarity between polypropylene and intumescent flame retardants leads to poor compatibility. Using intumescent flame retardants can affect the mechanical strength of polypropylene nonwoven fabrics. Furthermore, the affinity of intumescent flame retardants... Poor water resistance leads to increased moisture absorption in polypropylene nonwoven fabrics. Although silane coupling agents can be used for modification, the preparation and performance study of intumescent flame-retardant polypropylene materials (Wu Zhenghuan, Master's Thesis, South China University of Technology, December 2009) disclosed that after modifying intumescent flame retardants with vinyl silane coupling agents, the flame retardancy was improved, and the mechanical strength remained basically unchanged, but the elongation at break decreased. This is because the molecular chains of silane coupling agents are small. Although they can be coated on the surface of intumescent flame retardants through cross-linking surface modification, the length of the organic chain segments formed by cross-linking surface modification is insufficient to intertwine with the chain segments in polypropylene to form an interfacially compatible structure. Summary of the Invention

[0011] To address the shortcomings of existing technologies, this invention provides a dual-effect polypropylene nonwoven fabric color masterbatch for medical and health use with antibacterial and flame-retardant properties, and its preparation method. The prepared polypropylene nonwoven fabric color masterbatch has excellent antibacterial and flame-retardant properties. When applied to the preparation of polypropylene nonwoven fabric, it is less prone to filament breakage during spinning. The prepared polypropylene nonwoven fabric has uniform coloring, uniform antibacterial distribution, and high mechanical strength and elongation at break.

[0012] To solve the above technical problems, the technical solution adopted by the present invention is as follows: A method for preparing a medical and health-grade antibacterial and flame-retardant dual-effect polypropylene nonwoven fabric masterbatch includes: preparing a coated pigment, preparing an antibacterial agent, preparing a flame retardant, and granulation; The preparation of the coated pigment includes: dispersion treatment and coating; The dispersion process involves adding the pigment to a reaction vessel, adjusting the temperature of the reaction vessel to 80-85℃, adjusting the rotation speed to 300-400 r / min, stirring for 20-30 min, adding anhydrous ethanol solution of stearic acid dropwise, adjusting the rotation speed to 1400-1500 r / min after the addition is complete, stirring for 60-80 min, transferring to a centrifuge, adjusting the centrifuge speed to 8000-9000 r / min, centrifuging for 10-15 min, taking the precipitate, and vacuum drying the precipitate to obtain the dispersed pigment. In the dispersion treatment, the ratio of pigment to anhydrous ethanol solution of stearic acid is 100-110g:300-350mL. The dropping rate of the anhydrous ethanol solution of stearic acid is 5-10 mL / min; The pigments are: Pigment Blue 2, Pigment Blue 15, Pigment Blue 15:1, Pigment Blue 15:3, Pigment Blue 16, Pigment Blue 28, Pigment Blue 29, Pigment Blue 36, Pigment Blue 60, Pigment Blue 72, Pigment Green 17, Pigment Green 36, Pigment Green 50, Pigment Violet 2, Pigment Violet 19, Pigment Violet 29, Pigment Violet 37, Pigment Yellow 13, Pigment Yellow 14, Pigment Yellow 42, Pigment Yellow 53, Pigment Yellow 62, Pigment Yellow 65, Pigment Yellow 74, Pigment Yellow 83, Pigment Yellow 93, Pigment Yellow 95, Pigment Yellow 109, Pigment Yellow 110, Pigment Yellow 128, Pigment Yellow 147, Pigment Yellow 151, Pigment Yellow 154, Pigment Yellow 168, Pigment Yellow 180, Pigment Yellow 181, Pigment Yellow 183, Pigment Yellow 191:1, Pigment Yellow 215, Pigment Brown 6, Pigment Brown 23, Pigment Brown 24, Pigment Orange 13, Pigment Orange 16, Pigment Red 5, Pigment Red 48:2, Pigment Red 49:2, Pigment Red 52:2, Pigment Red 57:1, Pigment Red 68, Pigment Red 112, Pigment Red 122, Pigment Red 144, Pigment Red 146, Pigment Red 149, Pigment Red 166, Pigment Red 170, Pigment Red 177, Pigment Red 178, Pigment Red 179, Pigment Red 181, Pigment Red 187, Pigment Red 202, Pigment Red 207, Pigment Red 208, Pigment Red 209, Pigment Red 214, Pigment Red 220, Pigment Red 221, Pigment Red 247, Pigment Red 254, Pigment Red 264, Pigment Red 272, Pigment Black 7, Pigment Black 23, Pigment Black 28, one of the following: rutile titanium dioxide, anatase titanium dioxide; Preferably, the pigment is one of pigment blue 2, pigment green 17, pigment purple 2, pigment yellow 13, pigment brown 6, pigment orange 13, pigment red 5, and pigment black 7; The pigment has a wavelength of 400-600 nm. The anhydrous ethanol solution of stearic acid has a stearic acid mass concentration of 1%. The coating process involves adding polyvinylpyrrolidone and a first portion of water to a reaction vessel, adjusting the reaction vessel speed to 300-400 rpm, stirring at room temperature for 20-30 minutes, adding the dispersed pigment, stirring for 60-80 minutes, adding an aqueous solution of calcium chloride, stirring for 4-5 hours, transferring to a centrifuge, adjusting the centrifuge speed to 8000-9000 rpm, centrifuging for 10-15 minutes, collecting the precipitate, adding the precipitate and a second portion of water to the reaction vessel, adjusting the reaction vessel speed to 300-400 rpm, stirring at room temperature for 20-30 minutes, adding an aqueous solution of sodium carbonate, stirring for 4-5 hours, letting it stand for 50-60 hours, transferring to a centrifuge, adjusting the centrifuge speed to 8000-9000 rpm, centrifuging for 10-15 minutes, collecting the precipitate, and vacuum drying the precipitate to obtain the coated pigment. In the coating process, the ratio of polyvinylpyrrolidone, the first part of water, the dispersed pigment, the aqueous solution of calcium chloride, the second part of water, and the aqueous solution of sodium carbonate is 9-10g:1100-1200mL:90-100g:1400-1500mL:1000-1200mL:1000-1100mL. The polyvinylpyrrolidone is polyvinylpyrrolidone K90; The mass concentration of calcium chloride in the aqueous solution is 5%. The sodium carbonate aqueous solution has a sodium carbonate mass concentration of 5%. The preparation of the antibacterial agent includes: ball milling and dissolving; The ball milling process involves adding nano-montmorillonite and urea into a ball mill, adjusting the ball-to-material ratio of the ball mill to 5-6:1, adjusting the rotation speed to 300-400 r / m, and milling for 2-3 hours to obtain the ball milling material. In the ball milling process, the mass ratio of nano-montmorillonite to urea is 200-250:18-22; The average particle size of the nano-montmorillonite is 200 nm; The dissolution process involves adding sodium hydroxide, urea, and water to a reaction vessel, adjusting the reaction vessel speed to 300-400 rpm, stirring at room temperature for 20-30 minutes, adding chitosan, stirring for 10-20 minutes, transferring to a freezer, adjusting the freezer temperature to -30℃ to -20℃, allowing it to stand for 6-7 hours, stirring to thaw at room temperature, and after complete thawing, transferring it back to the reaction vessel, adjusting the reaction vessel speed to 300-400 rpm, adding ball milling material, stirring at room temperature for 2-3 hours, transferring it to a centrifuge, adjusting the centrifuge speed to 13000-14000 rpm, centrifuging for 20-25 minutes, taking the precipitate, washing it 3-4 times with deionized water, transferring it back to the reaction vessel, adjusting the reaction vessel temperature to 45-60℃, adjusting the stirring speed to 50-100 rpm, stirring for 60-80 minutes, and vacuum drying to obtain the antibacterial agent. In the dissolution process, the ratio of sodium hydroxide, urea, water, chitosan, and ball milling material is 80-85g:40-42g:1000-1100mL:28-30g:200-210g. The degree of deacetylation of the chitosan is 90%. The preparation of the flame retardant includes: mixing and modification; The mixing process involves adding piperazine pyrophosphate and sodium trimetaphosphate into a ball mill, adjusting the ball-to-material ratio of the ball mill to 5-6:1, adjusting the rotation speed to 300-400 r / m, ball milling for 2-3 hours, and then vacuum drying to obtain the mixture. In the mixture, the mass ratio of piperazine pyrophosphate to sodium trimetaphosphate is 500-520:28-30; The average particle size of the piperazine pyrophosphate is 500 nm; The modification involves adding the mixture and hydrogen-containing silicone oil into a reaction vessel, adjusting the temperature of the reaction vessel to 120-140℃, adjusting the rotation speed to 400-600r / m, and stirring for 50-70min to obtain a flame retardant. In the modification, the mass ratio of the mixture to the hydrogen-containing silicone oil is 500-530:5-6; The hydrogen content of the hydrogen-containing silicone oil is 1%; The granulation process involves adding carrier resin, coated pigment, antibacterial agent, flame retardant, additives, and auxiliary antibacterial agent into a high-speed mixer. The speed of the high-speed mixer is adjusted to 1000-1100 r / m, and the mixture is stirred at room temperature for 10-12 min. The mixture is then added to a twin-screw extruder for extrusion. The extrusion temperature of the twin-screw extruder is adjusted to 200-220℃, and the screw speed is adjusted to 50-100 r / m. The mixture is then cooled and pelletized to obtain medical and health-grade antibacterial and flame-retardant dual-effect polypropylene nonwoven fabric masterbatch. In the granulation process, the mass ratio of carrier resin, coating pigment, antibacterial agent, flame retardant, additive, and auxiliary antibacterial agent is 70-75:20-25:5-6:20-25:8-10:3-4. The carrier resin is homopolymer polypropylene or copolymer polypropylene; The additive is one or a combination of several of N,N'-ethylene bis-stearamide, polyethylene wax, and polypropylene wax; The auxiliary antibacterial agent is zinc stearate.

[0013] A medical and health-grade antibacterial and flame-retardant dual-effect polypropylene nonwoven fabric masterbatch prepared by the aforementioned preparation method.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The preparation method of the medical and health antibacterial and flame retardant dual-effect polypropylene nonwoven color masterbatch of the present invention uses coated pigment in the preparation. In the preparation of coated pigment, the pigment is first dispersed, specifically by using stearic acid to disperse the pigment to obtain the dispersed pigment. Then, it is coated, specifically by using polyvinylpyrrolidone to disperse the dispersed pigment in water. The hydrophobic end of polyvinylpyrrolidone combines with the dispersed pigment, and the hydrophilic end of polyvinylpyrrolidone faces the water. At the same time, polyvinylpyrrolidone can also combine calcium ions to coat a layer of calcium ions on the surface of the dispersed pigment. Then it is mixed with an aqueous solution of sodium carbonate. The carbonate ions combine with calcium ions on the surface of the dispersed pigment to form calcium carbonate. Unlike the prior art, the present invention adopts the method of first dispersing and then combining calcium carbonate, thereby avoiding pigment agglomeration and promoting the uniform distribution of calcium carbonate on its surface. (2) The preparation method of the medical and health antibacterial and flame-retardant dual-effect polypropylene nonwoven fabric masterbatch of the present invention uses an antibacterial agent in the preparation. In the preparation of the antibacterial agent, nano-montmorillonite and urea are first mixed and then ball-milled. Urea can increase the interlayer spacing of nano-montmorillonite to obtain ball milling material. Then, urea can break the hydrogen bonds inside the chitosan molecule at low temperature, thereby improving the solubility of chitosan in water. Chitosan is dissolved in water and then added to the ball milling material. Chitosan can insert into the interlayer of the ball milling material and be adsorbed onto the ball milling material. On the surface of the material, urea in the ball mill can also improve the binding force between it and chitosan. Then, during the heating process, chitosan itself undergoes cross-linking in the interlayer and surface of nano-montmorillonite, thereby improving the bonding strength between chitosan and ball mill, resulting in an antibacterial agent. In the preparation of the antibacterial agent, urea simultaneously plays the roles of improving the interlayer spacing of nano-montmorillonite, promoting chitosan dissolution, improving the binding force between nano-montmorillonite and chitosan, and promoting the uniform distribution of chitosan in the interlayer and surface of nano-montmorillonite. (3) The preparation method of the medical and health antibacterial and flame retardant dual-effect polypropylene nonwoven fabric masterbatch of the present invention uses a flame retardant in the preparation. In the preparation of the flame retardant, the surface of piperazine pyrophosphate is acidic. First, piperazine pyrophosphate is mixed with sodium trimetaphosphate and then ball-milled. Piperazine pyrophosphate and sodium trimetaphosphate can form intermolecular bonds, which can avoid the agglomeration of piperazine pyrophosphate and improve the surface roughness of piperazine pyrophosphate. Then, hydrogen-containing silicone oil is coated on its surface, so that more hydrogen-containing silicone oil can be combined, thereby improving the hydrophobicity and also improving the bonding force with polypropylene. (4) The polypropylene nonwoven fabric masterbatch prepared by this invention has a moisture content of 0.1-0.3%, a color difference of grade 5, an initial decomposition temperature of 312-318℃ in air, and a filterability (DF value) of 0.3-0.7 bar•cm. 2 / g; (5) The polypropylene nonwoven fabric masterbatch prepared by the present invention is less prone to filament breakage during spinning when applied to the preparation of polypropylene nonwoven fabric. (6) The polypropylene nonwoven fabric masterbatch prepared by the present invention has excellent antibacterial properties. The polypropylene nonwoven fabric prepared using the polypropylene nonwoven fabric masterbatch of the present invention has an inhibition rate of 99.18-99.76% against Staphylococcus aureus and an inhibition rate of 99.10-99.71% against Escherichia coli. (7) The polypropylene nonwoven fabric masterbatch prepared by the present invention has excellent flame retardancy. The polypropylene nonwoven fabric prepared using the polypropylene nonwoven fabric masterbatch of the present invention has a limiting oxygen index of 29.81-30.34%. (7) The polypropylene nonwoven fabric masterbatch prepared by the present invention produces polypropylene nonwoven fabric with uniform coloring. (8) The polypropylene nonwoven fabric masterbatch prepared by the present invention has uniform antibacterial distribution. Twenty spunbond nonwoven fabric samples were taken from the prepared polypropylene nonwoven fabric. The difference between the maximum and minimum inhibition rates against Staphylococcus aureus was 0.51-0.77%, and the difference between the maximum and minimum inhibition rates against Escherichia coli was 0.40-0.57%. (9) The polypropylene nonwoven fabric masterbatch prepared by the present invention produces polypropylene nonwoven fabric with high mechanical strength and elongation at break. The longitudinal breaking strength is 103.1-108.7 N / 5cm, the transverse breaking strength is 69.7-71.5 N / 5cm, the longitudinal breaking elongation is 59.7-63.1%, and the transverse breaking elongation is 65.8-69.5%. Detailed Implementation

[0015] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention are now described.

[0016] Example 1 A method for preparing a medical-grade antibacterial and flame-retardant dual-effect polypropylene nonwoven fabric masterbatch, specifically comprising: 1. Preparation of coated pigments: (1) Dispersion treatment: Add 100g of pigment to the reaction vessel, adjust the temperature of the reaction vessel to 80℃, adjust the speed to 300r / m, stir for 20min, add 300mL of anhydrous ethanol solution of stearic acid dropwise, adjust the dropwise speed to 5mL / min, after the dropwise addition is completed, adjust the speed to 1400r / m, stir for 60min, transfer to a centrifuge, adjust the speed of the centrifuge to 8000r / min, centrifuge for 10min, take the precipitate, vacuum dry the precipitate to obtain the pigment after dispersion treatment; The pigment is Pigment Blue 2; The pigment has a D90 particle size of 400 nm; The anhydrous ethanol solution of stearic acid has a stearic acid mass concentration of 1%. (2) Coating: Add 9g of polyvinylpyrrolidone and 1100mL of water to the reactor. Adjust the speed of the reactor to 300r / min and stir for 20min at room temperature. Add 90g of dispersed pigment and stir for 60min. Add 1400mL of calcium chloride aqueous solution and stir for 4h. Transfer to a centrifuge and adjust the speed of the centrifuge to 8000r / min. Centrifuge for 10min and take the precipitate. Add the precipitate and 1000mL of water to the reactor. Adjust the speed of the reactor to 300r / min and stir for 20min at room temperature. Add 1000mL of sodium carbonate aqueous solution and stir for 4h. Let stand for 50h. Transfer to a centrifuge and adjust the speed of the centrifuge to 8000r / min. Centrifuge for 10min and take the precipitate. Vacuum dry the precipitate to obtain the coated pigment. The polyvinylpyrrolidone is polyvinylpyrrolidone K90; The mass concentration of calcium chloride in the aqueous solution is 5%. The sodium carbonate aqueous solution has a sodium carbonate mass concentration of 5%. 2. Preparation of antibacterial agents: (1) Ball milling: Add 200g of nano montmorillonite and 18g of urea to the ball mill, adjust the ball-to-material ratio of the ball mill to 5:1, adjust the speed to 300r / m, and ball mill for 2 hours to obtain the ball mill material; The average particle size of the nano-montmorillonite is 200 nm; (2) Dissolving: Add 80g sodium hydroxide, 40g urea and 1000mL water to the reactor, adjust the speed of the reactor to 300r / m, stir for 20min at room temperature, add 28g chitosan, stir for 10min, transfer to the freezer, adjust the temperature of the freezer to -30℃, let stand for 6h, stir to thaw at room temperature, after complete thawing, transfer to the reactor, adjust the speed of the reactor to 300r / m, add 200g ball milling material, stir for 2h at room temperature, transfer to the centrifuge, adjust the speed of the centrifuge to 13000r / m, centrifuge for 20min, take the precipitate, wash with deionized water 3 times, transfer to the reactor, adjust the temperature of the reactor to 45℃, adjust the stirring speed to 50r / m, stir for 60min, vacuum dry to obtain the antibacterial agent; The degree of deacetylation of the chitosan is 90%. 3. Preparation of flame retardants: (1) Mixing: Add 500g piperazine pyrophosphate and 28g sodium trimetaphosphate to a ball mill, adjust the ball-to-material ratio of the ball mill to 5:1, adjust the speed to 300r / m, ball mill for 2h, and then vacuum dry to obtain the mixture; The average particle size of the piperazine pyrophosphate is 500 nm; (2) Modification: Add 500g of mixture and 5g of hydrogen-containing silicone oil to the reactor, adjust the temperature of the reactor to 120℃, adjust the speed to 400r / m, stir for 50min, and obtain flame retardant; The hydrogen content of the hydrogen-containing silicone oil is 1%; 4. Granulation: The carrier resin, coating pigment, antibacterial agent, flame retardant, additive, and auxiliary antibacterial agent are added to a high-speed mixer in a mass ratio of 70:20:5:20:8:3. The speed of the high-speed mixer is adjusted to 1000 r / m, and the mixture is stirred at room temperature for 10 min. The mixture is then fed into a twin-screw extruder for extrusion. The extrusion temperature of the twin-screw extruder is adjusted to 200℃, and the screw speed is adjusted to 50 r / m. After cooling and pelletizing, medical and health antibacterial and flame retardant dual-effect polypropylene nonwoven fabric masterbatch is obtained. The carrier resin is homopolymer polypropylene; The additive is N,N'-ethylenebis-stearamide; The auxiliary antibacterial agent is zinc stearate.

[0017] A medical and health-grade antibacterial and flame-retardant dual-effect polypropylene nonwoven fabric masterbatch prepared by the aforementioned preparation method.

[0018] Example 2 A method for preparing a medical-grade antibacterial and flame-retardant dual-effect polypropylene nonwoven fabric masterbatch, specifically comprising: 1. Preparation of coated pigments: (1) Dispersion treatment: Add 105g of pigment to the reaction vessel, adjust the temperature of the reaction vessel to 82℃, adjust the speed to 350r / m, stir for 25min, add 320mL of anhydrous ethanol solution of stearic acid dropwise, adjust the dropwise speed to 8mL / min, after the dropwise addition is completed, adjust the speed to 1450r / m, stir for 70min, transfer to a centrifuge, adjust the speed of the centrifuge to 8500r / min, centrifuge for 12min, take the precipitate, vacuum dry the precipitate to obtain the pigment after dispersion treatment; The pigment is Pigment Green 17; The pigment has a D90 particle size of 500 nm; The anhydrous ethanol solution of stearic acid has a stearic acid mass concentration of 1%. (2) Coating: Add 9.5g of polyvinylpyrrolidone and 1150mL of water to the reaction vessel, adjust the speed of the reaction vessel to 350r / min, stir for 25min at room temperature, add 95g of dispersed pigment, stir for 70min, add 1450mL of calcium chloride aqueous solution, stir for 4.5h, transfer to a centrifuge, adjust the speed of the centrifuge to 8500r / min, centrifuge for 15min, take the precipitate, add the precipitate and 1100mL of water to the reaction vessel, adjust the speed of the reaction vessel to 350r / min, stir for 20-30min at room temperature, add 1050mL of sodium carbonate aqueous solution, stir for 4.5h, let stand for 55h, transfer to a centrifuge, adjust the speed of the centrifuge to 8500r / min, centrifuge for 15min, take the precipitate, vacuum dry the precipitate to obtain the coated pigment; The polyvinylpyrrolidone is polyvinylpyrrolidone K90; The mass concentration of calcium chloride in the aqueous solution is 5%. The sodium carbonate aqueous solution has a sodium carbonate mass concentration of 5%. 2. Preparation of antibacterial agents: (1) Ball milling: Add 220g of nano montmorillonite and 20g of urea to the ball mill, adjust the ball-to-material ratio of the ball mill to 5:1, adjust the speed to 350r / m, and ball mill for 2.5h to obtain ball mill material; The average particle size of the nano-montmorillonite is 200 nm; (2) Dissolving: Add 82g sodium hydroxide, 41g urea and 1050mL water to the reactor, adjust the speed of the reactor to 350r / m, stir for 25min at room temperature, add 29g chitosan, stir for 15min, transfer to the freezer, adjust the temperature of the freezer to -25℃, let stand for 6.5h, stir to thaw at room temperature, after complete thawing, transfer to the reactor, adjust the speed of the reactor to 350r / m, add 205g ball milling material, stir for 2.5h at room temperature, transfer to the centrifuge, adjust the speed of the centrifuge to 13000r / m, centrifuge for 25min, take the precipitate, wash with deionized water 4 times, transfer to the reactor, adjust the temperature of the reactor to 50℃, adjust the stirring speed to 80r / m, stir for 70min, vacuum dry to obtain antibacterial agent; The degree of deacetylation of the chitosan is 90%. 3. Preparation of flame retardants: (1) Mixing: Add 510g piperazine pyrophosphate and 29g sodium trimetaphosphate to a ball mill, adjust the ball-to-material ratio of the ball mill to 5:1, adjust the speed to 350r / m, ball mill for 2.5h, and then vacuum dry to obtain a mixture; The average particle size of the piperazine pyrophosphate is 500 nm; (2) Modification: Add 520g of mixture and 5.5g of hydrogen-containing silicone oil to the reactor, adjust the temperature of the reactor to 130℃, adjust the speed to 500r / m, stir for 60min, and obtain flame retardant; The hydrogen content of the hydrogen-containing silicone oil is 1%; 4. Granulation: The carrier resin, coating pigment, antibacterial agent, flame retardant, additive, and auxiliary antibacterial agent are added to a high-speed mixer in a mass ratio of 72:23:5.5:22:9:3.5. The speed of the high-speed mixer is adjusted to 1100 r / m, and the mixture is stirred at room temperature for 11 min. The mixture is then fed into a twin-screw extruder for extrusion. The extrusion temperature of the twin-screw extruder is adjusted to 210℃, and the screw speed is adjusted to 70 r / m. After cooling and pelletizing, medical and health antibacterial and flame retardant dual-effect polypropylene nonwoven fabric masterbatch is obtained. The carrier resin is homopolymer polypropylene; The additive is polyethylene wax; The auxiliary antibacterial agent is zinc stearate.

[0019] A medical and health-grade antibacterial and flame-retardant dual-effect polypropylene nonwoven fabric masterbatch prepared by the aforementioned preparation method.

[0020] Example 3 A method for preparing a medical-grade antibacterial and flame-retardant dual-effect polypropylene nonwoven fabric masterbatch, specifically comprising: 1. Preparation of coated pigments: (1) Dispersion treatment: Add 110g of pigment to the reaction vessel, adjust the temperature of the reaction vessel to 85℃, adjust the speed to 400r / m, stir for 30min, add 350mL of anhydrous ethanol solution of stearic acid dropwise, adjust the dropwise speed to 10mL / min, after the dropwise addition is completed, adjust the speed to 1500r / m, stir for 80min, transfer to a centrifuge, adjust the speed of the centrifuge to 9000r / min, centrifuge for 15min, take the precipitate, vacuum dry the precipitate to obtain the pigment after dispersion treatment; The pigment is Pigment Violet 2; The pigment has a D90 particle size of 400-600 nm; The anhydrous ethanol solution of stearic acid has a stearic acid mass concentration of 1%. (2) Coating: Add 10g of polyvinylpyrrolidone and 1200mL of water to the reactor. Adjust the speed of the reactor to 400r / min and stir for 30min at room temperature. Add 100g of dispersed pigment and stir for 80min. Add 1500mL of calcium chloride aqueous solution and stir for 5h. Transfer to a centrifuge and adjust the speed of the centrifuge to 9000r / min. Centrifuge for 15min and take the precipitate. Add the precipitate and 1200mL of water to the reactor. Adjust the speed of the reactor to 400r / min and stir for 30min at room temperature. Add 1100mL of sodium carbonate aqueous solution and stir for 5h. Let stand for 60h. Transfer to a centrifuge and adjust the speed of the centrifuge to 9000r / min. Centrifuge for 15min and take the precipitate. Vacuum dry the precipitate to obtain the coated pigment. The polyvinylpyrrolidone is polyvinylpyrrolidone K90; The mass concentration of calcium chloride in the aqueous solution is 5%. The sodium carbonate aqueous solution has a sodium carbonate mass concentration of 5%. 2. Preparation of antibacterial agents: (1) Ball milling: Add 250g of nano montmorillonite and 22g of urea to the ball mill, adjust the ball-to-material ratio of the ball mill to 6:1, adjust the speed to 400r / m, and ball mill for 3h to obtain ball mill material; The average particle size of the nano-montmorillonite is 200 nm; (2) Dissolving: Add 85g sodium hydroxide, 42g urea and 1100mL water to the reactor, adjust the speed of the reactor to 400r / m, stir for 30min at room temperature, add 30g chitosan, stir for 20min, transfer to the freezer, adjust the temperature of the freezer to -20℃, let stand for 7h, stir to thaw at room temperature, after complete thawing, transfer to the reactor, adjust the speed of the reactor to 400r / m, add 210g ball milling material, stir for 3h at room temperature, transfer to the centrifuge, adjust the speed of the centrifuge to 14000r / m, centrifuge for 25min, take the precipitate, wash with deionized water 4 times, transfer to the reactor, adjust the temperature of the reactor to 60℃, adjust the stirring speed to 100r / m, stir for 80min, vacuum dry to obtain the antibacterial agent; The degree of deacetylation of the chitosan is 90%. 3. Preparation of flame retardants: (1) Mixing: Add 520g piperazine pyrophosphate and 30g sodium trimetaphosphate to a ball mill, adjust the ball-to-material ratio of the ball mill to 6:1, adjust the speed to 400r / m, ball mill for 3h, and then vacuum dry to obtain the mixture; The average particle size of the piperazine pyrophosphate is 500 nm; (2) Modification: Add 530g of mixture and 6g of hydrogen-containing silicone oil to the reactor, adjust the temperature of the reactor to 140℃, adjust the speed to 600r / m, stir for 70min, and obtain flame retardant; The hydrogen content of the hydrogen-containing silicone oil is 1%; 4. Granulation: The carrier resin, coating pigment, antibacterial agent, flame retardant, additive, and auxiliary antibacterial agent are added to a high-speed mixer in a mass ratio of 75:25:6:25:10:4. The speed of the high-speed mixer is adjusted to 1100 r / m, and the mixture is stirred at room temperature for 12 min. The mixture is then fed into a twin-screw extruder for extrusion. The extrusion temperature of the twin-screw extruder is adjusted to 220℃, and the screw speed is adjusted to 100 r / m. After cooling and pelletizing, medical and health antibacterial and flame retardant dual-effect polypropylene nonwoven fabric masterbatch is obtained. The carrier resin is homopolymer polypropylene; The additive is polypropylene wax; The auxiliary antibacterial agent is zinc stearate.

[0021] A medical and health-grade antibacterial and flame-retardant dual-effect polypropylene nonwoven fabric masterbatch prepared by the aforementioned preparation method.

[0022] Example 4 Based on the preparation method of medical and health antibacterial and flame retardant dual-effect polypropylene nonwoven fabric masterbatch in Example 1, the type of pigment is changed, specifically, pigment yellow 13 is used to replace pigment blue 2 by mass, and the D90 particle size of the pigment remains unchanged; the rest of the technical solutions are consistent with Example 1.

[0023] Example 5 Based on the preparation method of medical and health antibacterial and flame retardant dual-effect polypropylene nonwoven fabric masterbatch in Example 1, the type of pigment is changed. Specifically, pigment brown 6 is used to replace pigment blue 2 by mass, while the D90 particle size of the pigment remains unchanged; the rest of the technical solutions are consistent with Example 1.

[0024] Example 6 Based on the preparation method of medical and health antibacterial and flame retardant dual-effect polypropylene nonwoven fabric masterbatch in Example 1, the type of pigment is changed. Specifically, pigment orange 13 is used to replace pigment blue 2 by mass, while the D90 particle size of the pigment remains unchanged; the rest of the technical solutions are consistent with Example 1.

[0025] Example 7 Based on the preparation method of medical and health antibacterial and flame retardant dual-effect polypropylene nonwoven fabric masterbatch in Example 1, the type of pigment is changed, specifically, pigment red 5 is used to replace pigment blue 2 by mass, while the D90 particle size of the pigment remains unchanged; the rest of the technical solutions are consistent with Example 1.

[0026] Example 8 Based on the preparation method of medical and health antibacterial and flame retardant dual-effect polypropylene nonwoven fabric masterbatch in Example 1, the type of pigment is changed, specifically, pigment black 7 is used to replace pigment blue 2 by mass, while the D90 particle size of the pigment remains unchanged; the rest of the technical solutions are consistent with Example 1.

[0027] Comparative Example 1 Based on the preparation method of medical and health antibacterial and flame retardant dual-effect polypropylene nonwoven fabric masterbatch in Example 1, in the first step of preparing the coating pigment, the dispersion treatment step (1) is omitted, and in the coating step (2), the same mass of pigment with D90 particle size of 400nm is used to replace the pigment after dispersion treatment. The remaining technical solutions are consistent with those in Example 1.

[0028] Comparative Example 2 Based on the preparation method of medical and health antibacterial and flame retardant dual-effect polypropylene nonwoven fabric masterbatch in Example 1, in the second step of preparing antibacterial agent, the ball milling step (1) is omitted, and in the dissolution step (2), nano montmorillonite with an average particle size of 200 nm is used to replace the ball milling material. The remaining technical solutions are consistent with those in Example 1.

[0029] Comparative Example 3 Based on the preparation method of medical and health antibacterial and flame-retardant dual-effect polypropylene nonwoven fabric masterbatch in Example 1, the dissolution step in step (2) of the antibacterial agent preparation step is changed to: Add 30g anhydrous acetic acid and 1500mL water to a reaction vessel, adjust the reaction vessel speed to 300r / m, stir at room temperature for 20min, add 28g chitosan, stir for 30min, add 200g ball milling material, stir at room temperature for 2h, transfer to a centrifuge, adjust the centrifuge speed to 13000r / m, centrifuge for 20min, take the precipitate, wash it 3 times with deionized water, transfer it to a reaction vessel, adjust the reaction vessel temperature to 45℃, adjust the stirring speed to 50r / m, stir for 60min, and vacuum dry to obtain the antibacterial agent; The degree of deacetylation of the chitosan is 90%. The remaining technical solutions are consistent with those in Example 1.

[0030] Comparative Example 4 Based on the preparation method of medical and health antibacterial and flame retardant dual-effect polypropylene nonwoven fabric masterbatch in Example 1, in the third step of preparing flame retardant, the mixing step in step (1) is omitted, and in the modification step in step (2), piperazine pyrophosphate with an average particle size of 500 nm is used to replace sodium tripolyphosphate by mass. The remaining technical solutions are consistent with those in Example 1.

[0031] Performance Test 1 The moisture content, color difference, initial decomposition temperature in air, and filterability (DF value) of the medical and health antibacterial and flame-retardant dual-effect polypropylene nonwoven masterbatches prepared in Examples 1-8 and Comparative Examples 1-4 were tested. The test results are as follows:

[0032] The results above show that the color difference and filterability test results of the masterbatch of Comparative Example 1 are worse than those of the masterbatch of Example 1; the filterability test results of the masterbatch of Comparative Example 2 are worse than those of the masterbatch of Example 1.

[0033] Performance Test 2 The medical-grade antibacterial and flame-retardant dual-effect polypropylene nonwoven fabric masterbatch prepared in Examples 1-8 and Comparative Examples 1-4 was mixed with polypropylene chips and light stabilizer UV-3346 at a mass ratio of 4:94:2 to prepare a fabric with an areal density of 50 g / m³. 2 The spunbond nonwoven fabric with a single fiber diameter of 20 μm was prepared, and the presence of fiber breakage issues was observed during the preparation process. The results are as follows:

[0034] The results above show that the masterbatches of Comparative Example 1 and Comparative Example 2 have filament breakage problems in the preparation of spunbond nonwoven fabric.

[0035] The antibacterial rate of spunbond nonwoven fabric against Staphylococcus aureus and Escherichia coli was tested according to GB / T 20944.2-2007 standard. The test results are as follows:

[0036] The results above show that the antibacterial rate of the spunbond nonwoven fabric prepared by the masterbatch of Comparative Example 2 and Comparative Example 3 is lower than that of the spunbond nonwoven fabric prepared by the masterbatch of Example 1.

[0037] The limiting oxygen index of spunbond nonwoven fabric was tested according to GB / T 5455-2014 standard, and the test results are as follows:

[0038] The results above show that the spunbond nonwoven fabrics prepared from the masterbatches of Examples 1-8 and Comparative Examples 1-4 all have good flame retardancy.

[0039] The following are the results of the observations regarding whether there is uneven coloring in spunbond nonwoven fabric:

[0040] The results above show that the spunbond nonwoven fabrics prepared from the masterbatches of Comparative Example 1 and Comparative Example 2 have the problem of uneven coloring.

[0041] Meanwhile, to verify whether the antibacterial distribution was uniform, a total of 20 spunbond nonwoven fabric samples were repeatedly taken. The inhibition rates of these 20 samples against Staphylococcus aureus and Escherichia coli were tested according to GB / T20944.2-2007 standard. The difference between the maximum and minimum inhibition rates against Staphylococcus aureus and Escherichia coli was calculated, and the results are as follows:

[0042] The results above show that the spunbond nonwoven fabric prepared with the masterbatch of Comparative Example 2 has the problem of uneven antibacterial rate.

[0043] The breaking strength and elongation at break of spunbond nonwoven fabric were tested, and the results are as follows:

[0044] The results above show that the breaking strength and breaking elongation of the spunbond nonwoven fabrics prepared by the masterbatch of Comparative Example 1, Comparative Example 3, and Comparative Example 4 are lower than those of the spunbond nonwoven fabric prepared by the masterbatch of Example 1.

Claims

1. A method for preparing a medical-grade antibacterial and flame-retardant dual-effect polypropylene nonwoven fabric masterbatch, characterized in that, include: Preparation of coated pigments, preparation of antibacterial agents, preparation of flame retardants, granulation; The preparation of the coated pigment includes: dispersion treatment and coating; The dispersion treatment involves dispersing the pigment at 80-85°C, then adding anhydrous ethanol solution of stearic acid dropwise to the pigment, stirring, centrifuging, taking the precipitate, and vacuum drying to obtain the dispersed pigment. The coating process involves mixing polyvinylpyrrolidone and a first portion of water, stirring at room temperature, adding the dispersed pigment, stirring, adding an aqueous solution of calcium chloride, stirring, centrifuging, taking the precipitate, mixing the precipitate with a second portion of water, stirring at room temperature, adding an aqueous solution of sodium carbonate, stirring, letting stand, centrifuging, taking the precipitate, and vacuum drying to obtain the coated pigment. The preparation of the antibacterial agent includes: ball milling and dissolving; The ball milling process involves ball milling nano-montmorillonite and urea to obtain abrasive material. The dissolution process involves mixing sodium hydroxide, urea, and water, stirring at room temperature, adding chitosan, stirring, allowing it to stand at -30°C to -20°C, stirring to thaw at room temperature, and mixing with ball milling material after complete thawing. The mixture is then stirred at room temperature, centrifuged, the precipitate is collected, washed, stirred at 45-60°C, and vacuum dried to obtain the antibacterial agent. The preparation of the flame retardant includes: mixing and modification; The mixing process involves ball milling piperazine pyrophosphate and sodium trimetaphosphate, followed by vacuum drying to obtain a mixture. The modification involves mixing the mixture and hydrogen-containing silicone oil, then stirring at 120-140°C to obtain a flame retardant.

2. The preparation method of the medical and health antibacterial and flame-retardant dual-effect polypropylene nonwoven fabric masterbatch according to claim 1, characterized in that, In the dispersion process, the ratio of pigment to anhydrous ethanol solution of stearic acid is 100-110g:300-350mL.

3. The preparation method of the medical and health antibacterial and flame-retardant dual-effect polypropylene nonwoven fabric masterbatch according to claim 1, characterized in that, In the dispersion process, the dropping rate of the anhydrous ethanol solution of stearic acid is 5-10 mL / min; The pigments are: Pigment Blue 2, Pigment Blue 15, Pigment Blue 15:1, Pigment Blue 15:3, Pigment Blue 16, Pigment Blue 28, Pigment Blue 29, Pigment Blue 36, Pigment Blue 60, Pigment Blue 72, Pigment Green 17, Pigment Green 36, Pigment Green 50, Pigment Violet 2, Pigment Violet 19, Pigment Violet 29, Pigment Violet 37, Pigment Yellow 13, Pigment Yellow 14, Pigment Yellow 42, Pigment Yellow 53, Pigment Yellow 62, Pigment Yellow 65, Pigment Yellow 74, Pigment Yellow 83, Pigment Yellow 93, Pigment Yellow 95, Pigment Yellow 109, Pigment Yellow 110, Pigment Yellow 128, Pigment Yellow 147, Pigment Yellow 151, Pigment Yellow 154, Pigment Yellow 168, Pigment Yellow 180, Pigment Yellow 181, Pigment Yellow 183, Pigment Yellow 191:1, Pigment Yellow 215, Pigment Brown 6, Pigment Brown 23, Pigment Brown 24, Pigment Orange 13, Pigment Orange 16, Pigment Red 5, Pigment Red 48:2, Pigment Red 49:2, Pigment Red 52:2, Pigment Red 57:1, Pigment Red 68, Pigment Red 112, Pigment Red 122, Pigment Red 144, Pigment Red 146, Pigment Red 149, Pigment Red 166, Pigment Red 170, Pigment Red 177, Pigment Red 178, Pigment Red 179, Pigment Red 181, Pigment Red 187, Pigment Red 202, Pigment Red 207, Pigment Red 208, Pigment Red 209, Pigment Red 214, Pigment Red 220, Pigment Red 221, Pigment Red 247, Pigment Red 254, Pigment Red 264, Pigment Red 272, Pigment Black 7, Pigment Black 23, Pigment Black 28, one of the following: rutile titanium dioxide, anatase titanium dioxide; The pigment has a wavelength of 400-600 nm. The mass concentration of stearic acid in the anhydrous ethanol solution of stearic acid is 1%.

4. The method for preparing medical and health-grade antibacterial and flame-retardant dual-effect polypropylene nonwoven fabric masterbatch according to claim 1, characterized in that, In the coating process, the ratio of polyvinylpyrrolidone, the first part of water, the dispersed pigment, the aqueous solution of calcium chloride, the second part of water, and the aqueous solution of sodium carbonate is 9-10g:1100-1200mL:90-100g:1400-1500mL:1000-1200mL:1000-1100mL. The polyvinylpyrrolidone is polyvinylpyrrolidone K90; The mass concentration of calcium chloride in the aqueous solution is 5%. The sodium carbonate aqueous solution has a sodium carbonate mass concentration of 5%.

5. The method for preparing medical and health-grade antibacterial and flame-retardant dual-effect polypropylene nonwoven fabric masterbatch according to claim 1, characterized in that, In the ball milling process, the mass ratio of nano-montmorillonite to urea is 200-250:18-22; The average particle size of the nano-montmorillonite is 200 nm.

6. The method for preparing medical and health-grade antibacterial and flame-retardant dual-effect polypropylene nonwoven fabric masterbatch according to claim 1, characterized in that, In the dissolution process, the ratio of sodium hydroxide, urea, water, chitosan, and ball milling material is 80-85g:40-42g:1000-1100mL:28-30g:200-210g. The degree of deacetylation of the chitosan is 90%.

7. The method for preparing medical and health-grade antibacterial and flame-retardant dual-effect polypropylene nonwoven fabric masterbatch according to claim 1, characterized in that, In the mixture, the mass ratio of piperazine pyrophosphate to sodium trimetaphosphate is 500-520:28-30; The average particle size of the piperazine pyrophosphate is 500 nm.

8. The method for preparing medical and health-grade antibacterial and flame-retardant dual-effect polypropylene nonwoven fabric masterbatch according to claim 1, characterized in that, In the modification, the mass ratio of the mixture to the hydrogen-containing silicone oil is 500-530:5-6; The hydrogen content of the hydrogen-containing silicone oil is 1%.

9. The method for preparing medical and health-grade antibacterial and flame-retardant dual-effect polypropylene nonwoven fabric masterbatch according to claim 1, characterized in that, The granulation process involves mixing carrier resin, coated pigment, antibacterial agent, flame retardant, additive, and auxiliary antibacterial agent, stirring at room temperature, melting and extruding, cooling, and pelletizing to obtain medical and health antibacterial and flame retardant dual-effect polypropylene nonwoven fabric masterbatch. In the granulation process, the mass ratio of carrier resin, coating pigment, antibacterial agent, flame retardant, additive, and auxiliary antibacterial agent is 70-75:20-25:5-6:20-25:8-10:3-4. The carrier resin is homopolymer polypropylene or copolymer polypropylene; The additive is one or a combination of several of N,N'-ethylene bis-stearamide, polyethylene wax, and polypropylene wax; The auxiliary antibacterial agent is zinc stearate.

10. A medical and health-grade antibacterial and flame-retardant dual-effect polypropylene nonwoven fabric masterbatch prepared by the preparation method according to any one of claims 1-9.

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