A composition for a lightweight breathable bottom film of hygiene products and a method for preparing the breathable bottom film.

Abstract

This invention relates to the field of hygiene products, and provides a composition of a lightweight breathable bottom film for hygiene products and a method for preparing the breathable bottom film, which solves the defects of the prior art breathable bottom film having complex preparation process, poor breathability, and poor deodorization effect; the composition of the lightweight breathable bottom film for hygiene products includes the following raw materials in parts by weight: 5-20 parts by weight of hydrophobic deodorizing silica and 100 parts by weight of polyolefin resin, wherein the hydrophobic deodorizing silica is prepared by modifying silica with alkylating agent, deodorizing agent and antibacterial agent.

Description

Technical Field

[0001] This invention relates to the field of hygiene products, and more particularly to a composition of a lightweight breathable bottom film for hygiene products and a method for preparing the breathable bottom film. Background Technology

[0002] Disposable hygiene products typically consist of a liquid-permeable top layer, an absorbent core, and a liquid-impermeable bottom layer, stacked sequentially from top to bottom. The liquid-impermeable layer is composed of a breathable membrane and a non-woven fabric. Traditional breathable membranes usually only have the properties of being breathable but not waterproof. However, when disposable hygiene products are used, urine often seeps in and produces an odor. To remove the odor, current technology often achieves this by improving the material composition of the absorbent core. However, improvements to the materials in the absorbent core may affect its absorbency and diffusion properties.

[0003] Chinese Patent Application No. 202110301464.6 discloses an antibacterial and deodorizing diaper, comprising a permeable surface layer, an absorbent core for absorbing liquid, and a bottom layer to prevent urine leakage, forming a front waist area, a crotch area, and a back waist area. The surface layer has a unidirectional moisture-wicking composite structure. The upper surface layer of the surface layer is a non-woven fabric web made of hydrophobic fibers, and the upper surface of the upper surface layer includes several raised structures. The lower surface layer of the surface layer includes a hydrophilic non-woven layer made of antibacterial fibers. The bottom layer includes a PE bottom film and a non-woven protective layer covering the PE bottom film. An deodorizing layer is disposed on the outer surface of the PE bottom film. This application achieves deodorization by placing the deodorizing layer on the PE film, and its deodorizing layer is a printed layer. Since the deodorizing layer and the PE film are separate structural layers, the manufacturing process becomes complicated when applied to disposable hygiene products. In addition, because it is a printed layer, the air permeability of the PE film is also affected.

[0004] Chinese Patent No. 201210294577.9 discloses an absorbent article containing a tea polyphenol deodorizing composition, comprising, from top to bottom, a liquid-permeable top sheet, an absorbent core, and a bottom membrane, wherein the absorbent core contains the tea polyphenol deodorizing composition. This invention enables the absorbent article to possess multi-dimensional odor control functions in addition to traditional absorption properties. By encapsulating tea polyphenols with cyclodextrin, the stability of the tea polyphenols is enhanced, and the influence of the tea polyphenols' color on the absorbent article is avoided. This invention achieves its deodorizing effect by adding a tea polyphenol deodorizing composition to the absorbent core; however, the bottom membrane is not modified and therefore has no deodorizing effect. Summary of the Invention

[0005] Therefore, in view of the above problems, the present invention provides a composition of a lightweight breathable bottom film for hygiene products and a method for preparing the breathable bottom film, which solves the defects of the prior art in that the breathable bottom film is complicated in preparation process, has poor breathability, and has poor deodorization effect.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a composition of a lightweight breathable bottom film for hygiene products, comprising the following raw materials in parts by weight: 5-20 parts by weight of hydrophobic and deodorizing silica, and 100 parts by weight of polyolefin resin, wherein the hydrophobic and deodorizing silica is prepared by modifying silica with alkylating agents, deodorizing agents and antibacterial agents.

[0007] Furthermore, the hydrophobic deodorizing silica is prepared by the following steps: (1) Prepare raw materials: use fumed silica as raw material; (2) Add alkylating agent to the fumed silica in step (1), the mass ratio of the alkylating agent to the fumed silica is 5-20:100, react for 0.5-2h, and control the reaction temperature at 150-200℃ to obtain hydrophobic silica; (3) Add ethanol, deodorizing agent and antibacterial agent solution to the hydrophobic silica in step (2) at room temperature, stir for 1-4h, centrifuge, filter and dry, and control the moisture content to within 400ppm to obtain hydrophobic deodorizing silica.

[0008] Furthermore, the alkylating agent is any one of hexamethyldisilazane, trimethoxyoctadecylsilane, dimethyldichlorosilane, and trimethylchlorosilane.

[0009] Furthermore, the deodorizer is a plant-based deodorizer containing any one of arginine, glycine, alanine, or amino acid cations, and the solid content of the deodorizer is 30-35 wt%.

[0010] Furthermore, the mass ratio of the deodorizer, antibacterial agent, ethanol and hydrophobic silica is 0.2-1:0.1-1:50-100:20-50.

[0011] Furthermore, the silica particles have a diameter of 10-100 nm, an average adsorption pore size of 0.1-1.0 nm, and a specific surface area of ​​100-500 m². 2 / g.

[0012] A method for preparing a lightweight deodorizing and breathable bottom film for sanitary products includes the following preparation steps: (1) mixing the composition of the lightweight breathable bottom film for sanitary products described above with a processing aid and stirring evenly to obtain mixture B; (2) mixing the composition of the lightweight breathable bottom film for sanitary products described above with a nucleating agent, an anti-shrinkage agent, and a foaming agent evenly to obtain mixture A; (3) adding mixture A and mixture B to a first screw extruder and a second screw extruder respectively, melting at high temperature, mixing through a distributor to form an ABA structure melt or an AB structure melt, foaming and extruding through a die, and cooling to obtain a thick cast sheet; (4) stretching the cast sheet through a stretching mechanism for four stages, with stretching ratios of 1.1-1.3, 1.4-1.5, 1.6-1.7, and 1.5-1.6 respectively; (5) then shaping and cooling to produce a lightweight deodorizing and breathable bottom film.

[0013] Furthermore, the stretching ratios of the four stages of stretching in step (3) are 1.3, 1.5, 1.7, and 1.6.

[0014] Furthermore, the processing aids include nano-titanium dioxide, fillers, coupling agents, and dispersants.

[0015] Furthermore, the amount of the processing aid is 0.5-5 wt% of the polyolefin resin.

[0016] Furthermore, the antibacterial agent is chitosan.

[0017] By adopting the aforementioned technical solution, the beneficial effects of the present invention are as follows:

[0018] 1. The breathable bottom membrane of the present invention is mainly made of hydrophobic deodorizing silica and polyolefin resin. The hydrophobic deodorizing silica is made by modifying silica with alkylating agents, deodorizing agents and antibacterial agents. By using alkylating agents to react with hydroxyl groups on the surface of silica and controlling the degree of alkylation, silica particles with hydrophobic surface and hydrophilic internal pores are prepared. Then, by using the hydrogen bonding between the carboxyl and amino groups of plant deodorizing agents and the amino and carboxyl groups of antibacterial agents and the hydroxyl groups of the internal pores of porous silica particles, the plant deodorizing agents and antibacterial agents are loaded into the hydrophilic internal pores of porous silica particles, so that the hydrophobic silica particles have deodorizing and antibacterial properties.

[0019] 2. This invention improves the raw materials of the breathable bottom membrane, enabling the breathable bottom membrane to have deodorizing function on its own. Compared with the two independent deodorizing layers and PE film layers of the prior art, the preparation process is simpler when applied, and the breathability is better because it does not use deodorizing material coated on the outer surface of the PE film. Attached Figure Description

[0020] Figure 1(a) Water droplet contact angle diagram of alkylated silica particles; (b) Water droplet contact angle diagram of deodorizing loaded alkylated silica particles.

[0021] Figure 2 These are high-resolution TEM images and EDS spectra of alkylated silica particles;

[0022] Figure 3 These are high-resolution TEM images and EDS spectra of deodorizing loaded alkylated silica particles. Detailed Implementation

[0023] Example 1

[0024] refer to Figures 1 to 3 A composition of a lightweight breathable bottom film for hygiene products, comprising the following raw materials in parts by weight: 5 parts by weight of hydrophobic deodorizing silica and 100 parts by weight of polyolefin resin, wherein the hydrophobic deodorizing silica is prepared by modifying silica with alkylating agent, deodorizing agent and antibacterial agent, wherein the deodorizing agent is a plant deodorizing agent with arginine having a solid content of 30 wt%, and the antibacterial agent is chitosan;

[0025] The hydrophobic deodorizing silica is prepared by the following steps: (1) Prepare raw materials: use fumed silica as raw material; (2) add hexamethyldisilazane to the fumed silica in step (1), the mass ratio of hexamethyldisilazane to fumed silica is 5:100, react for 0.5 h, and control the reaction temperature at 150 °C to obtain hydrophobic silica; (3) add ethanol, plant deodorizing agent containing 30 wt% arginine and chitosan to the hydrophobic silica in step (2) at room temperature, stir for 1 h, centrifuge, filter and dry, and control the moisture content to within 400 ppm to obtain hydrophobic deodorizing silica.

[0026] The mass ratio of arginine, chitosan, ethanol and hydrophobic silica is 0.2:0.1:50:20.

[0027] The silica particles have a diameter of 10 nm, an average adsorption pore size of 0.1 nm, and a specific surface area of ​​100 m². 2 / g.

[0028] A method for preparing a lightweight deodorizing and breathable bottom film for sanitary products includes the following preparation steps: (1) mixing the above-mentioned composition of the lightweight breathable bottom film for sanitary products with a processing aid, wherein the processing aid is specifically nano-titanium dioxide, calcium carbonate, titanate coupling agent, and polyethylene wax, and the amount of the processing aid is 2 wt% of the polyolefin resin, that is, the processing aid is 2 parts by weight, more specifically, 0.5 parts by weight of titanium dioxide, 0.6 parts by weight of calcium carbonate, 0.4 parts by weight of titanate coupling agent, and 0.5 parts by weight of polyethylene wax, stirring evenly to obtain mixture B; (2) mixing the above-mentioned composition of the lightweight deodorizing and breathable bottom film for sanitary products with a processing aid, wherein the processing aid is specifically nano-titanium dioxide, calcium carbonate, titanate coupling agent, and polyethylene wax, and stirring evenly to obtain mixture B; In step (1), the composition of the lightweight breathable bottom film of the sanitary products is mixed evenly with the nucleating agent, anti-shrinkage agent and foaming agent to obtain mixture A; (3) mixture A and mixture B are added to the first screw extruder and the second screw extruder respectively, melted at high temperature, and mixed through the distributor to form an ABA structure melt or an AB structure melt, which is then foamed and extruded through the die and cooled to obtain a thick casting sheet; (4) the casting sheet is stretched in four stages by the stretching mechanism, with stretching ratios of 1.3, 1.5, 1.7 and 1.6 respectively; (5) after shaping and cooling, a lightweight deodorizing breathable bottom film is made.

[0029] Example 2

[0030] A composition for a lightweight, breathable bottom film of a hygiene product comprises the following raw materials in parts by weight: 15 parts by weight of hydrophobic and deodorizing silica, and 100 parts by weight of polyolefin resin. The hydrophobic and deodorizing silica is prepared by modifying silica with an alkylating agent, a deodorizing agent, and an antibacterial agent. The alkylating agent is trimethoxyoctadecylsilane, the deodorizing agent is a plant-based deodorizing agent containing 33 wt% alanine, and the antibacterial agent is chitosan.

[0031] The amino and carboxyl groups in alanine can neutralize the acidic or alkaline components in the odor-causing substances produced by urination, forming neutral substances and thus reducing the intensity of the odor. In addition, the molecular structure of amino acids also contains many polar groups, which have certain adsorption properties and can adsorb onto the surface of odor-causing substances, reducing the amount of odor-causing substances released into the air and thus reducing the perception of odor-causing substances.

[0032] The hydrophobic and deodorizing silica is prepared by the following steps: (1) Prepare raw materials: use fumed silica as raw material; (2) add trimethoxyoctadecylsilane to the fumed silica in step (1), the mass ratio of trimethoxyoctadecylsilane to the fumed silica is 10:100, react for 1.5 h, and control the reaction temperature at 180 °C to obtain hydrophobic silica; (3) add ethanol, alanine and amino acid antibacterial agent solution to the hydrophobic silica in step (2) at room temperature, stir for 2.5 h, centrifuge, filter and dry, and control the moisture content to within 400 ppm to obtain hydrophobic and deodorizing silica.

[0033] The mass ratio of the deodorizer, antibacterial agent, ethanol and hydrophobic silica is 0.5:0.4:70:35.

[0034] The silica particles have a diameter of 50 nm, an average adsorption pore size of 0.6 nm, and a specific surface area of ​​300 m². 2 / g.

[0035] A method for preparing a lightweight deodorizing and breathable bottom film for sanitary products includes the following preparation steps: (1) mixing the above-mentioned composition of the lightweight breathable bottom film for sanitary products with a processing aid and stirring evenly to obtain mixture B; (2) mixing the composition of the lightweight breathable bottom film for sanitary products obtained in step (1) with a nucleating agent, an anti-shrinkage agent and a foaming agent evenly to obtain mixture A; (3) adding mixture A and mixture B to a first screw extruder and a second screw extruder respectively, melting at high temperature, mixing through a distributor to form an ABA structure melt or an AB structure melt, foaming and extruding through a die, and cooling to obtain a thick casting sheet; (4) stretching the casting sheet through a stretching mechanism for four stages, with stretching ratios of 1.1, 1.4, 1.6 and 1.5 respectively; (5) then shaping and cooling to produce a lightweight deodorizing and breathable bottom film.

[0036] The processing aids include nano-titanium dioxide, fillers, coupling agents, and dispersants. The amount of the processing aids is 3 wt% of the polyolefin resin, that is, 3 parts by weight of the processing aids, of which 0.8 parts by weight of titanium dioxide, 1.0 parts by weight of filler, 0.6 parts by weight of coupling agent, and 0.6 parts by weight of dispersant are used. The filler is calcium carbonate, the coupling agent is a silane coupling agent, and the dispersant is polyethylene wax.

[0037] Example 3

[0038] A composition for a lightweight, breathable bottom film of a hygiene product comprises the following raw materials in parts by weight: 20 parts by weight of hydrophobic and deodorizing silica, and 100 parts by weight of polyolefin resin. The hydrophobic and deodorizing silica is prepared by modifying silica with an alkylating agent, a deodorizing agent, and an antibacterial agent. The alkylating agent is dimethyldichlorosilane, the antibacterial agent is chitosan, and the deodorizing agent is a plant-based deodorizing agent containing 35 wt% alanine.

[0039] The hydrophobic deodorizing silica is prepared by the following steps: (1) Prepare raw materials: use fumed silica as raw material; (2) Add alkylating agent to the fumed silica in step (1), the mass ratio of the alkylating agent to the fumed silica is 20:100, react for 2 hours, and control the reaction temperature at 200°C to obtain hydrophobic silica; (3) Add ethanol, deodorizing agent and antibacterial agent solution to the hydrophobic silica in step (2) at room temperature, stir for 4 hours, centrifuge, filter and dry, and control the moisture content to within 400 ppm to obtain hydrophobic deodorizing silica.

[0040] The mass ratio of the deodorizer, antibacterial agent, ethanol and hydrophobic silica is 1:1:100:50.

[0041] The silica particles have a diameter of 100 nm, an average adsorption pore size of 1.0 nm, and a specific surface area of ​​500 m². 2 / g.

[0042] A method for preparing a lightweight deodorizing and breathable bottom film for sanitary products includes the following preparation steps: (1) mixing the above-mentioned composition of the lightweight breathable bottom film for sanitary products with a processing aid and stirring evenly to obtain mixture B; (2) mixing the composition of the lightweight breathable bottom film for sanitary products obtained in step (1) with a nucleating agent, an anti-shrinkage agent and a foaming agent evenly to obtain mixture A; (3) adding mixture A and mixture B to a first screw extruder and a second screw extruder respectively, melting at high temperature, mixing through a distributor to form an ABA structure melt or an AB structure melt, foaming and extruding through a die, and cooling to obtain a thick casting sheet; (4) stretching the casting sheet through a stretching mechanism for four stages, with stretching ratios of 1.3, 1.5, 1.7 and 1.6 respectively; (5) then shaping and cooling to produce a lightweight deodorizing and breathable bottom film.

[0043] The processing aids include nano-titanium dioxide, fillers, coupling agents, and dispersants. The amount of the processing aids is 5 wt% of the polyolefin resin, that is, 1 part by weight of titanium dioxide, 1.2 parts by weight of fillers, 1.8 parts by weight of coupling agents, and 1 part by weight of dispersants.

[0044] In addition, the deodorizer of the present invention can also be a plant-based deodorizer containing amino acid cations, and the solid content of the deodorizer is 30-35 wt%, which can achieve the purpose of the present invention.

[0045] refer to Figures 1 to 3 The modified deodorizing silica particles in all embodiments possess both hydrophobic and deodorizing properties. Water droplet shape analysis was performed by separately attaching the hydrophobic silica particles and the hydrophobic deodorizing silica particles to glass plates, such as... Figure 1 As shown, pure silica particles are highly hydrophilic. When a water droplet is placed on the particle surface, it is immediately absorbed, exhibiting a contact angle of 0°. The contact angle of the hydrophobically modified silica particles is 139.5°, indicating that they have good hydrophobicity. Furthermore, the contact angle of the hydrophobically deodorizing silica particles after further deodorizing modification is 134.2°, indicating that the deodorizing modified particles still possess strong hydrophobicity, and the deodorizing agent treatment has little effect on their hydrophobicity.

[0046] The deodorizing performance of hydrophobic deodorizing silica particles was analyzed using a detection tube according to the method in GB / T 33610.2-2017. The hydrophobic deodorizing silica particles achieved a 98.8% reduction in ammonia concentration, demonstrating good deodorizing effect.

[0047] Example 4

[0048] An odor-repellent adult diaper includes a liquid-permeable top layer, an absorbent core, and an impermeable bottom layer stacked sequentially from top to bottom. The absorbent core is composed of 10 parts by weight of superabsorbent polymer resin, 2 parts by weight of silica, 5 parts by weight of surfactant, 1 part by weight of essential oil, 0.5 parts by weight of acrylic water-based adhesive, and 900 parts by weight of fluff pulp. The impermeable bottom layer is composed of a hydrophobic deodorizing and breathable membrane and a hydrophobic nonwoven fabric laminated to the bottom of the hydrophobic deodorizing and breathable membrane. The hydrophobic deodorizing and breathable membrane is composed of 5 parts by weight of hydrophobic deodorizing silica, 100 parts by weight of polyolefin resin, and 3 parts by weight of processing aids.

[0049] The preparation method of the hydrophobic deodorizing silica is as follows: (1) Prepare raw materials: use fumed silica as raw material; (2) add hexamethyldisilazane to the fumed silica in step (1), the mass ratio of the alkylating agent to the fumed silica is 5:100, react for 0.5 h, and control the reaction temperature at 150 °C to obtain hydrophobic silica; (3) add ethanol and a plant deodorizing agent solution containing arginine to the hydrophobic silica in step (2) at room temperature, stir for 1 h, centrifuge, filter and dry, and control the moisture content to within 400 ppm to obtain hydrophobic deodorizing silica.

[0050] The plant-based deodorizer has a solid content of 30 wt%, and the mass ratio of the plant-based deodorizer, ethanol, and hydrophobic silica is 0.2:50:20. The silica has a particle size of 18 nm, an average adsorption pore size of 0.24 nm, and a specific surface area of ​​215 m². 2 / g.

[0051] The preparation process of the absorbent is as follows: a) Add surfactant to essential oil for emulsification, so that the essential oil is coated by surfactant; b) Mix superabsorbent polymer with silica with a pore size of 10nm evenly, and add acrylic water-based adhesive to bond the superabsorbent polymer and silica together; c) Add the emulsified essential oil from step a to the material from step b, mix and stir evenly to obtain a preform; d) Feed the preform and fluff pulp into a mold cavity according to the ratio, mold, and then demold to obtain the absorbent.

[0052] Example 5

[0053] A method for preparing deodorizing adult diapers includes the following preparation process:

[0054] (1) Prepare a liquid-permeable surface layer;

[0055] (2) Preparation of absorbent: a. Add surfactant to essential oil for emulsification, so that the essential oil is coated by surfactant; b. Mix superabsorbent polymer with silica with a pore size of 10 nm evenly, and add acrylic water-based adhesive to bond the superabsorbent polymer and silica together; c. Add the emulsified essential oil from step a to the material from step b, mix and stir evenly to obtain a preform; d. Feed the preform and fluff pulp into a mold cavity according to the ratio, mold, and then demold to obtain absorbent;

[0056] (3) Preparation of an impermeable liquid-proof bottom layer: The hydrophobic nonwoven fabric is unwound and transported online, and a hydrophobic deodorizing and breathable membrane is laminated on its surface online. The preparation method of the hydrophobic deodorizing and breathable membrane includes the following steps: a. Mixing 50 parts by weight of hydrophobic deodorizing silica, 100 parts by weight of polyolefin resin, and 3 parts by weight of processing aid, stirring evenly to obtain a mixture; b. Feeding the mixture into a screw extruder, and performing melt extrusion and cooling; c. Performing four-stage stretching through a stretching mechanism, with stretching ratios of 1.3, 1.5, 1.7, and 1.6 respectively; d. Then shaping and cooling.

[0057] The preparation method of hydrophobic deodorizing silica is as follows: a) Prepare raw materials: use fumed silica as raw material; b) Add alkylating agent to the fumed silica in step (1), the mass ratio of the alkylating agent to the fumed silica is 5-20:100, react for 1 hour, and control the reaction temperature at 150℃ to obtain hydrophobic silica; c) Add ethanol and deodorizing agent solution to the hydrophobic silica in step (2) at room temperature, stir for 2 hours, centrifuge, filter and dry, and control the moisture content to within 400 ppm to obtain hydrophobic deodorizing silica;

[0058] (4) The liquid-permeable top layer, absorbent body and liquid-impermeable bottom layer of the online transmission are combined into one piece, and then cut to obtain individual deodorizing disposable sanitary products.

[0059] The nucleating agent, anti-shrinkage agent, and foaming agent of this invention are all materials known in the prior art and will not be described in detail here.

[0060] Although the invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the invention without departing from the spirit and scope of the invention as defined in the appended claims, all of which shall be within the scope of protection of the invention.

Claims

1. A composition for a lightweight, breathable bottom film of hygiene products, characterized in that, The raw materials include the following parts by weight: 5-20 parts by weight of hydrophobic deodorizing silica and 100 parts by weight of polyolefin resin. The hydrophobic deodorizing silica is prepared by the following steps: (1) Prepare raw materials: use fumed silica as raw material; (2) Add alkylating agent to the fumed silica in step (1), the mass ratio of the alkylating agent to the fumed silica is 5-20:100, react for 0.5-2h, and control the reaction temperature at 150-200℃ to obtain hydrophobic silica; (3) Add ethanol, deodorizing agent and antibacterial agent solution to the hydrophobic silica in step (2) at room temperature, stir for 1-4h, centrifuge, filter and dry, and control the moisture content to within 400ppm to obtain hydrophobic deodorizing silica; The deodorizer is a plant-based deodorizer containing any one of arginine, glycine, alanine, or amino acid cations, and the solid content of the deodorizer is 30-35 wt%.

2. The composition for a lightweight breathable bottom film of sanitary products according to claim 1, characterized in that: The alkylating agent is any one of hexamethyldisilazane, trimethoxyoctadecylsilane, dimethyldichlorosilane, and trimethylchlorosilane.

3. The composition for a lightweight breathable bottom film of sanitary products according to claim 1, characterized in that: The mass ratio of the deodorizer, antibacterial agent, ethanol and hydrophobic silica is 0.2-1:0.1-1:50-100:20-50.

4. The composition for a lightweight breathable bottom film of sanitary products according to claim 1, characterized in that: The silica particles have a diameter of 10-100 nm, an average adsorption pore size of 0.1-1.0 nm, and a specific surface area of ​​100-500 m². 2 / g.

5. A method for preparing a lightweight deodorizing and breathable bottom film for hygiene products, characterized in that, The preparation steps include: (1) mixing the composition of the lightweight breathable bottom film for sanitary products according to any one of claims 1 to 4 with a processing aid and stirring evenly to obtain mixture B; (2) mixing the composition of the lightweight breathable bottom film for sanitary products according to any one of claims 1 to 4 with a nucleating agent, an anti-shrinkage agent and a foaming agent evenly to obtain mixture A; (3) adding mixture A and mixture B to the first screw extruder and the second screw extruder respectively, melting at high temperature, mixing through a distributor to form an ABA structure melt or an AB structure melt, foaming and extruding through a die, cooling to obtain a thick casting sheet; (4) stretching the casting sheet through a stretching mechanism for four stages, with stretching ratios of 1.1-1.3, 1.4-1.5, 1.6-1.7, and 1.5-1.6 respectively; (5) then shaping and cooling to produce a lightweight deodorizing breathable bottom film.

6. The method for preparing a lightweight deodorizing and breathable bottom film for hygiene products according to claim 5, characterized in that: The processing aids include nano-titanium dioxide, fillers, coupling agents, and dispersants.

7. The method for preparing a lightweight deodorizing and breathable bottom film for hygiene products according to claim 6, characterized in that: The amount of the processing aid is 0.5-5 wt% of the polyolefin resin.

8. The method for preparing a lightweight deodorizing and breathable bottom film for hygiene products according to claim 5, characterized in that: The antibacterial agent is chitosan.

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