High-permeability hygienic product containing core shift fibers and preparation method of high-permeability hygienic product

Abstract

The invention relates to the technical field of hygienic products, and particularly discloses a high-permeability hygienic product containing core shift fibers and a preparation method of the high-permeability hygienic product. A high-permeability hygienic product containing core shift fibers comprises a high-permeability non-woven fabric, and the high-permeability non-woven fabric comprises ES core shift fibers of a skin-core double-component structure. The skin layer of the ES core shift fiber comprises the following raw materials in parts by weight: 30-50 parts of PE resin, 25-40 parts of PE grafted acrylic acid and 8-13 parts of graphene oxide; a core layer of the ES core shift fiber is prepared from the following raw materials in parts by weight: 45-65 parts of PET resin, 15-25 parts of hyperbranched polyester and 15-25 parts of composite microspheres. According to the high-permeability hygienic product containing the core shift fibers, on the basis that the original excellent mechanical property is kept, the liquid absorption and infiltration capacity is remarkably improved, and the softness and comfort of the hygienic product are further improved.

Description

Technical Field

[0001] The present application relates to the technical field of sanitary products, and more particularly, to a high-permeability sanitary product comprising eccentric fibers and a preparation method thereof. Background Art

[0002] With the widespread use of sanitary products such as sanitary napkins, panty liners, diapers, and more, core performance indicators such as liquid absorption rate, liquid storage capacity, reverse osmosis control, and comfort have become key indicators for evaluating product quality. Existing PE-PET sheath-core composite fibers, due to their unique structural design and material properties, impart excellent softness, skin affinity, and mechanical properties. They are widely used in the production of sanitary products such as sanitary nonwovens and various types of sanitary protective products such as diapers, bandages, and cotton balls.

[0003] However, although the traditional PE-PET skin-core structured composite fiber can provide good comfort when used in sanitary products, the inherent hydrophobicity of the PE material leads to poor hydrophilicity of the fiber surface, making it difficult for liquid to quickly penetrate into the core layer, resulting in liquid retention on the surface and inability to be quickly absorbed, causing side leakage and other problems. Although the PET core layer has a certain liquid absorption capacity, the water absorption capacity is limited, and the liquid is easy to reversely seep from the fiber, making it impossible to keep the surface dry, reducing the comfort of use of sanitary products.

[0004] Regarding the above-mentioned related technologies, the inventors found that in order to improve the liquid absorption and permeability of sanitary products, most of the existing technologies improve the water absorption of sanitary products by simply compounding or blending different fibers such as special-section polyester and ordinary spandex, or increasing the weaving density. However, this often sacrifices the mechanical properties of the sanitary products, fails to balance the various performances of the sanitary products, and reduces their breathability and comfort. Summary of the Invention

[0005] In order to improve the liquid absorption and penetration capacity of sanitary products, balance the water absorption capacity and mechanical properties of sanitary products, and further enhance the softness and comfort of sanitary products, the present application provides a high-permeability sanitary product comprising eccentric fibers and a preparation method thereof.

[0006] In a first aspect, the present application provides a high-permeability sanitary product comprising eccentric fibers, which adopts the following technical solution: A high-permeability sanitary product comprising eccentric fibers, comprising a high-permeability nonwoven fabric, wherein the high-permeability nonwoven fabric comprises ES eccentric fibers having a sheath-core bicomponent structure; According to parts by weight, the raw materials for the skin layer of the ES eccentric core fiber include 30-50 parts of PE resin, 25-40 parts of PE grafted acrylic acid, and 8-13 parts of graphene oxide; The core layer raw materials of the ES eccentric fiber include 45-65 parts of PET resin, 15-25 parts of hyperbranched polyester, and 15-25 parts of composite microspheres.

[0007] When preparing non-woven fabric using the ES eccentric fiber structure, the surface hydrophilicity of the PE cortex is significantly enhanced by adding graphene oxide and grafting acrylic acid to the PE matrix. Under the action of the lamellar structure of graphene oxide, liquid can quickly penetrate into the core layer to achieve rapid diversion.

[0008] In the core layer of the ES eccentric fiber, by using hyperbranched polyester and composite microspheres with a hollow porous structure, the highly branched molecular chain structure of hyperbranched polyester and the hollow porous structure of the composite microspheres form a gradient diversion network. The strong water absorption of the fiber core layer promotes the speed of liquid absorption and penetration from the cortex to the core layer. After the liquid penetrates into the core layer, it can achieve rapid lateral diffusion under the action of the gradient diversion network in the core layer, avoiding the penetration blockage caused by local saturation and optimizing the uniformity of liquid distribution. The hollow porous composite microspheres can further expand after absorbing liquid, expanding the internal pores of the core layer and providing a larger space for liquid storage capacity, significantly enhancing the liquid absorption, penetration, and liquid storage capabilities of the ES eccentric fiber.

[0009] By adopting the above technical solution, the water absorption and penetration limitations of traditional PE-PET eccentric fibers are effectively improved. On the premise of retaining the soft comfort and excellent mechanical properties of ES eccentric fibers, it can quickly absorb liquid and penetrate into the core layer for storage, preventing problems such as side leakage caused by liquid retention on the surface and inability to quickly penetrate and absorb, keeping the surface of sanitary products dry, and improving the comfort of using sanitary products.

[0010] Optionally, the PE resin is LDPE, and the PE matrix resin in the PE grafted with acrylic acid is HDPE.

[0011] LDPE has the characteristics of low crystallinity and high flexibility, and can form a more loose entanglement network during the fiber forming process, endowing the ES eccentric fiber with good soft comfort. The high density of HDPE can provide a rigid support for grafting acrylic acid, preventing the collapse deformation caused by excessive softening. After acrylic acid grafting modification, the wettability of the PE cortex is enhanced, effectively reducing the resistance of the ES eccentric fiber to water absorption, and realizing the rapid water absorption of the ES eccentric fiber and then penetration and storage in the core layer.

[0012] By adopting the above technical solution, selecting high-density HDPE for grafting acrylic acid and then mixing it with low-density LDPE as the matrix of the cortex achieves the balance between the mechanical stability and hydrophilic permeability of the cortex, prevents the problem of cortex cracking, and at the same time maintains the soft comfort of the ES eccentric fiber.

[0013] Optionally, the hyperbranched polyester is a carboxyl-terminated hyperbranched polyester.

[0014] The carboxyl-terminated hyperbranched polyester has strong hydrophilicity and good compatibility with the PET matrix, can significantly reduce the contact angle of the fiber core layer, enhance the liquid absorption capacity of the fiber, and the molecular structure of the hyperbranched polyester has a three-dimensional structure with high branching degree and low entanglement, which can form a large number of nano-micron-sized pores in the PET core layer, and the porosity can be further increased after liquid absorption, forming a dynamic liquid storage space.

[0015] By adopting the above technical solution, selecting the carboxyl-terminated hyperbranched polyester can promote the diversion effect and increase the liquid absorption and storage capacity in the core layer of the ES eccentric fiber, effectively improve the problem of poor water absorption of the PET core layer, and enhance the water absorption and permeability of the ES eccentric fiber.

[0016] Optionally, the composite microspheres are hollow porous microspheres with a carboxyl-terminated hyperbranched polyester as the core and polyvinyl alcohol as the shell.

[0017] Optionally, the preparation method of the composite microspheres includes the following steps: Dissolve the carboxyl-terminated hyperbranched polyester in tetrahydrofuran to prepare solution A with a concentration of 20-22 mg / mL, and dissolve polyvinyl alcohol in water to prepare solution B with a concentration of 3-4 mg / mL; Mix solution A, solution B and water, stir and react, then centrifuge and wash to obtain prefabricated microspheres, then disperse them in MES buffer solution, add a cross-linking agent, stir and react at room temperature, centrifuge and wash, and then freeze-dry to obtain hollow porous composite microspheres.

[0018] Optionally, the cross-linking agent is carbodiimide and N-hydroxysuccinimide with a mass ratio of 1:(0.8-1).

[0019] As an organic solvent, tetrahydrofuran has good solubility for both the carboxyl-terminated hyperbranched polyester and polyvinyl alcohol. When solution A as the dispersed phase and solution B as the continuous phase are mixed, by the solvent evaporation method, as tetrahydrofuran slowly evaporates, the diffusion rate of tetrahydrofuran inside the core layer to the outside is faster than the replenishment of the external solvent, resulting in the formation of a depletion zone in the center of the core layer, thus forming a hollow structure. The solubility of the carboxyl-terminated hyperbranched polyester in the mixed solution decreases, triggering progressive phase separation. In this process, on the one hand, the shape of droplets is formed, and polyvinyl alcohol preferentially accumulates on the surface of the droplets to form core-shell microspheres. On the other hand, a microphase-separated network structure is formed inside the polymer, and pores are left after the evaporation of the organic solvent, forming a hollow porous microsphere structure.

[0020] Both the carboxyl-terminated hyperbranched polyester and polyvinyl alcohol are strong water-absorbing substances, which can reduce the water penetration resistance, and can quickly attract water molecules into the internal pores of the composite microspheres when absorbing liquid. The hollow porous structure provides a diffusion path for water molecules, endowing the composite microspheres with strong water absorption and permeability.

[0021] Furthermore, the composite microspheres were crosslinked using the EDC / NHS system. EDC first reacted with carboxyl groups to form highly reactive O-acylisourea intermediates, and then reacted with NHS to form stable NHS esters, achieving strong chemical bonding between hyperbranched polyester and polyvinyl alcohol. This preferentially improved the mechanical properties and processing resistance of the composite microspheres. The crosslinked network could prevent the composite microspheres from breaking during subsequent spinning processes and also prevent the composite microspheres from swelling excessively after absorbing water, thus maintaining structural integrity, preserving the pore structure, and ensuring rapid liquid penetration.

[0022] By adopting the above technical solution, the hollow porous microspheres with a hyperbranched polyester core capped with carboxyl groups and a polyvinyl alcohol shell can, as the core layer raw material, achieve the expansion of the hollow structure of the high-efficiency liquid storage microspheres after absorbing liquid, further opening the pores of the fibers, forming a secondary flow guiding effect, and further enhancing the liquid absorption, penetration, and liquid storage capabilities of the fibers.

[0023] Optionally, the highly permeable non-woven fabric further includes bamboo fibers and profiled-section polyester fibers, and the mass ratio of the ES eccentric fibers, bamboo fibers, and profiled-section polyester fibers is (8 - 10):(2 - 4):1.

[0024] Optionally, the cross-sectional shape of the profiled-section polyester fibers is cross-shaped or Y-shaped.

[0025] By adopting the above technical solution, with ES eccentric fibers as the main body, bamboo fibers supplementing hydrophilicity, softness, and antibacterial properties, and blending a small amount of profiled-section polyester fibers, it can significantly increase the pores between the non-woven fabric fibers, form a three-dimensional flow guiding channel, and assist in flow guiding. When the non-woven fabric absorbs liquid, the liquid can be quickly spread and diffused in the surface layer and then absorbed and stored by the ES eccentric fibers, improving the liquid absorption and penetration ability of the non-woven fabric, effectively preventing the problem of local liquid accumulation, reducing liquid backflow and side leakage problems caused by the inability to quickly absorb liquid, and enhancing the comfort of using sanitary products.

[0026] In a second aspect, the present application provides a method for preparing a highly permeable sanitary product containing eccentric fibers, adopting the following technical solution: A method for preparing a highly permeable sanitary product containing eccentric fibers, comprising the following steps: Mix PE resin, PE grafted with acrylic acid, and graphene oxide, and obtain the skin layer material through melt extrusion; mix PET resin, hyperbranched polyester, and composite microspheres, and then obtain the core layer material through melt extrusion; compound spin, wind, bundle, stretch, heat-set, crimp, and cut the skin layer material and the core layer material according to a mass ratio of (1 - 1.2):1 to obtain ES eccentric fibers; The ES eccentric fiber and the profiled-section polyester fiber are opened, mixed, carded, cross-laid, and drawn to obtain a first fiber web; the bamboo fiber is opened, carded, cross-laid, and drawn to obtain a second fiber web; the first fiber web is placed on the top and the second fiber web is placed on the bottom, and they are hydroentangled into one body and dried to obtain a high-permeability non-woven fabric. The high-permeability non-woven fabric is used as the surface layer material of the sanitary product, and according to the production method of the sanitary product, a high-permeability sanitary product containing eccentric fibers is obtained.

[0027] By adopting the above technical solution, the ES eccentric fiber and the profiled-section polyester fiber are opened, mixed, carded, cross-laid, and drawn to obtain a first fiber web as the upper layer for the hydroentanglement of the non-woven fabric, making the surface layer hydrophilic. When absorbing liquid, with the assistance of a small amount of profiled-section polyester fibers, it can quickly conduct liquid transversely and spread, and through the hydrophilicity of the ES eccentric fiber cortex, it can quickly absorb and penetrate the liquid to the core layer of the ES eccentric fiber, and conduct liquid diffusion and store the liquid; the second fiber web obtained by carding and laying the bamboo fiber is used as the lower layer for the hydroentanglement of the non-woven fabric. The natural hydrophilicity and antibacterial property of the bamboo fiber further supplement the performance of the non-woven fabric surface layer, enhance the liquid storage capacity of the non-woven fabric surface layer. When the prepared non-woven fabric is used as the surface layer material to prepare sanitary products, it significantly improves the liquid absorption and permeability and the high-efficiency liquid storage capacity of the sanitary products, balances the water absorption capacity and mechanical properties of the sanitary products, and further improves the soft comfort of the sanitary products.

[0028] Optionally, the graphene oxide is pretreated as follows before being mixed with raw materials such as PE resin and PE grafted with acrylic acid: The graphene oxide is dispersed in water to form a graphene oxide dispersion; the chitosan quaternary ammonium salt is dissolved in water, and the pH is adjusted to 4.8 - 5.2 to form a surface treatment solution. The graphene oxide dispersion is mixed with the surface treatment solution to form a blend. The mass ratio of graphene oxide to chitosan quaternary ammonium salt in the blend is 1:(8 - 10). After heating and stirring for reaction, it is filtered, washed, and dried to obtain pretreated graphene oxide.

[0029] By adopting the above technical solution, the chitosan quaternary ammonium salt is cationically modified by adsorbing on the surface of the graphene oxide. The quaternary ammonium group can form a chemical bond interaction with the carboxyl group of the PE grafted with acrylic acid and the carboxyl group of the core layer end-carboxyl hyperbranched polyester, effectively promoting the uniform dispersion of the graphene oxide in the cortex raw materials and enhancing the interfacial bonding ability between the graphene oxide and the PE matrix, as well as between the cortex and the core layer.

[0030] In summary, the present application has the following beneficial effects: 1. Since the ES eccentric fiber made of a PE skin layer containing graphene oxide and a PET core layer containing highly water-absorbent hollow porous composite microspheres can quickly divert and penetrate the liquid to the core layer after absorbing the liquid, and the core layer can absorb the liquid with a high capacity, high absorption, penetration, and locking of the liquid are achieved. On the basis of retaining the good mechanical properties of the ES eccentric fiber, the water absorption and permeability of the ES eccentric fiber are effectively improved.

[0031] 2. In this application, hollow porous microspheres preferably made with hyperbranched polyester capped with carboxyl groups as the core and polyvinyl alcohol as the shell are used. A hollow porous structure is formed through solvent evaporation-induced phase separation, which can efficiently absorb, penetrate, and store the liquid. The hollow porous structure expands after absorbing the liquid, which can further expand the fiber pores, forming a secondary diversion effect, further enhancing the liquid absorption, penetration, and liquid storage capabilities of the ES eccentric fiber, locking the moisture. Through the cross-linking effect between the cross-linking agent and the carboxyl-capped hyperbranched polyester and polyvinyl alcohol, the structural stabilization of the hollow porous microspheres is achieved, improving the dispersibility of the composite microspheres when mixed with other core layer raw materials, and also strengthening the structural stability of the hollow porous structure during the subsequent spinning and forming process.

[0032] 3. The non-woven fabric prepared from ES eccentric fiber, bamboo fiber, and profiled cross-section polyester fiber as raw materials for the surface layer material of sanitary products can form a three-dimensional diversion channel in the surface layer after absorbing the liquid, quickly spreading the liquid in the surface layer, preventing local liquid accumulation, and reducing the occurrence of liquid backflow. The ES eccentric fiber dominates the acceleration of liquid penetration and storage, and the bamboo fiber further enhances the liquid absorption and storage, effectively reducing the problem of liquid retention on the surface of sanitary products during use and the inability to quickly absorb, which may cause side leakage, and improving the comfort of using sanitary products. Detailed implementation mode

[0033] The following examples further illustrate this application in detail.

[0034] Raw materials Except as otherwise specified, the raw materials used in the preparation examples, implementation examples, and comparative examples of this application are all commercially available products, specifically: Bamboo fiber, filament, with a diameter of 15 ± 3 mm and a linear density of 25 ± 3 tex; Profiled cross-section polyester fiber, with a cross shape and a specification of 75D / 36F; LDPE resin, selected from Yanshan Petrochemical, LD615; HDPE resin, selected from Fushun Petrochemical, 2911; Sodium polyacrylate, selected from Jiezhiyuan Water Treatment Materials, J-SN513; PET resin, with intrinsic viscosity of 0.7 - 1 dL / g, selected from Qinghua Plastic Factory in Jizhou District, Hengshui City, product number PET-QH, brand Qh-pet; Graphene oxide, selected from Zhejiang Zhitaina Micro New Materials Co., Ltd., DN-20DY; Chitosan quaternary ammonium salt, selected from Shandong Weikang Biopharmaceutical Technology Co., Ltd., chitosan quaternary ammonium salt 01; Carboxyl-terminated hyperbranched polyester, selected from Wuhan Hyperbranched Resin Technology Co., Ltd., HyPer C302; Polyvinyl alcohol, selected from Zhengzhou Yufan Biotechnology Co., Ltd., YF-H61; Carbodiimide (EDC), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, selected from Shanghai Yuanye Bio-Technology Co., Ltd., S30053; N-hydroxysuccinimide (NHS), selected from Shanghai Yuanye Bio-Technology Co., Ltd., S20179. Preparation example of composite microspheres

[0035] Preparation example 1 Preparation method of composite microspheres, including the following steps: S1: Dissolve carboxyl-terminated hyperbranched polyester in tetrahydrofuran to prepare solution A with a concentration of 21.5 mg / mL, and dissolve polyvinyl alcohol in deionized water to prepare solution B with a concentration of 3 mg / mL; S2: Mix 1 mL of solution B with 30 mL of deionized water for dilution. Under stirring, add 1 mL of solution A dropwise to the diluted solution B at a dropping rate of 0.05 mL / s, and continuously stir for 20 h to gradually volatilize tetrahydrofuran. After centrifugal washing, a hollow and porous prefabricated microsphere with carboxyl-terminated hyperbranched polyester as the core and polyvinyl alcohol as the shell is obtained; S3: Disperse the prefabricated microspheres in MES buffer solution, add carbodiimide and N-hydroxysuccinimide with a mass ratio of 1:1 as crosslinking agents, and the dosage of the crosslinking agents is 5.6% of the prefabricated microspheres. Stir at room temperature for 10 h, centrifugally wash, and then freeze-dry to obtain hollow and porous composite microspheres.

[0036] Preparation example 2 Preparation method of composite microspheres, including the following steps: S1: Dissolve carboxyl-terminated hyperbranched polyester in tetrahydrofuran to prepare solution A with a concentration of 22 mg / mL, and dissolve polyvinyl alcohol in deionized water to prepare solution B with a concentration of 4 mg / mL; S2: Dilute 1 mL of Solution B by mixing it with 30 mL of deionized water. While stirring, add 1 mL of Solution A to the diluted Solution B at a dropping rate of 0.05 mL / s. Continuously stir for 20 h to gradually volatilize tetrahydrofuran. After centrifugal washing, obtain prefabricated microspheres with a hollow porous morphology, which are made with hyperbranched polyester capped with carboxyl groups as the core and polyvinyl alcohol as the shell. S3: Disperse the prefabricated microspheres in MES buffer solution. Add carbodiimide and N-hydroxysuccinimide with a mass ratio of 1:0.9 as crosslinking agents. The dosage of the crosslinking agents is 5% of the mass of the prefabricated microspheres. Stir at room temperature for 10 h, then perform centrifugal washing and freeze-drying to obtain hollow porous composite microspheres.

[0037] Preparation Example 3 A preparation method for composite microspheres, comprising the following steps: S1: Dissolve hyperbranched polyester capped with carboxyl groups in tetrahydrofuran to prepare Solution A with a concentration of 20 mg / mL. Dissolve polyvinyl alcohol in deionized water to prepare Solution B with a concentration of 4 mg / mL. S2: Dilute 1 mL of Solution B by mixing it with 30 mL of deionized water. While stirring, add 1 mL of Solution A to the diluted Solution B at a dropping rate of 0.05 mL / s. Continuously stir for 20 h to gradually volatilize tetrahydrofuran. After centrifugal washing, obtain prefabricated microspheres with a hollow porous morphology, which are made with hyperbranched polyester capped with carboxyl groups as the core and polyvinyl alcohol as the shell. S3: Disperse the prefabricated microspheres in MES buffer solution. Add carbodiimide and N-hydroxysuccinimide with a mass ratio of 1:0.8 as crosslinking agents. The dosage of the crosslinking agents is 4.5% of the mass of the prefabricated microspheres. Stir at room temperature for 10 h, then perform centrifugal washing and freeze-drying to obtain hollow porous composite microspheres.

[0038] Preparation Example 4 A preparation method for composite microspheres, comprising the following steps: S1: Dissolve the carboxyl-terminated polyester (acid value is 60 mg KOH / g, average molecular weight is 3000 g / mol) in tetrahydrofuran to prepare Solution A with a concentration of 21.5 mg / mL. Dissolve polyvinyl alcohol in deionized water to prepare Solution B with a concentration of 3 mg / mL. S2: Dilute 1 mL of Solution B by mixing it with 30 mL of deionized water. While stirring, add 1 mL of Solution A to the diluted Solution B at a dropping rate of 0.05 mL / s. Continuously stir for 20 h to gradually volatilize tetrahydrofuran. After centrifugal washing, obtain prefabricated microspheres with a carboxyl-terminated polyester as the core and polyvinyl alcohol as the shell. S3: Disperse the prefabricated microspheres in MES buffer solution, add carbodiimide and N-hydroxysuccinimide with a mass ratio of 1:1 as crosslinking agents, and the dosage of the crosslinking agents is 5.6% of the prefabricated microspheres. Stir at room temperature for 10 h, centrifuge, wash, and then freeze-dry to obtain composite microspheres. Example Example 1

[0039] A highly permeable sanitary product containing eccentric fibers, including highly permeable non-woven fabric, which is made of ES eccentric fibers, bamboo fibers and profiled cross-section polyester fibers. The ES eccentric fibers are a skin-core bicomponent structure, and the raw materials and dosages are shown in Table 1. Among them, the PE resin is LDPE resin, the hyperbranched polyester is carboxyl-terminated hyperbranched polyester, the composite microspheres are obtained from Preparation Example 1, and the dispersant is sodium polyacrylate.

[0040] Table 1

[0041] The preparation method of the above highly permeable sanitary product containing eccentric fibers includes the following steps: (1) Preparation of ES eccentric fibers S1: Use HDPE as the matrix resin, acrylic acid as the graft monomer, and dicumyl peroxide as the initiator. The dosage of the graft monomer is 8% of the HDPE matrix resin, and the dosage of the initiator is 0.5% of the HDPE matrix resin. Add the matrix resin, graft monomer and initiator to a low-speed mixer in sequence, mix at a rotation speed of 120 r / min for 3 min, and then perform extrusion granulation and drying with a screw extruder to obtain PE grafted acrylic acid. The temperatures of each zone of the screw extruder are: Zone 1 170 °C, Zone 2 175 °C, Zone 3 175 °C, Zone 4 180 °C, Zone 5 180 °C, Zone 6 175 °C; S2: Mix PE resin, PE grafted acrylic acid, graphene oxide, antioxidant and dispersant, and obtain a melt through melting with a screw extruder to prepare the skin layer material. The temperatures of each zone of the screw extruder are: The temperatures of each zone of the screw extruder: Zone 1 200 °C, Zone 2 210 °C, Zone 3 220 °C, Zone 4 230 °C, Zone 5 235 °C, Zone 6 240 °C; S3: Mix PET resin, hyperbranched polyester, composite microspheres and antioxidant, and obtain a melt through melting with a screw extruder to prepare the core layer material. The temperatures of each zone of the screw extruder are: Zone 1 250 °C, Zone 2 255 °C, Zone 3 265 °C, Zone 4 275 °C, Zone 5 275 °C, Zone 6 270 °C; S4: The cortical material and the core material are compound spun, wound, bundled, stretched, heat-set, crimped, and cut at a mass ratio of 1:1 to obtain ES eccentric fibers. The spinning temperature is 285°C, the cut length is 40 mm, the side blowing temperature is 14°C, the side blowing humidity is 80%, the main pressure of the crimper is 0.14 MPa, the side pressure is 0.15 MPa, the back pressure is 0.08 MPa, the winding speed is 1.2 kg / min, the draw ratio is 3.6, the drawing temperature is 75°C, and the heat-setting temperature is 110°C in zone 1, 105°C in zone 2, and 105°C in zone 3; (2) Preparation of the highly permeable non-woven fabric S1: The ES eccentric fibers and the profiled-section polyester fibers are separately opened, mixed, carded, cross-laid, and drawn to obtain the first fiber web; S2: The bamboo fibers are opened, carded, cross-laid, and drawn to obtain the second fiber web; S3: The first fiber web is placed on top and the second fiber web is placed at the bottom, and they are overlapped into one body by hydroentangling and then dried to obtain the highly permeable non-woven fabric with a grammage of (40±2) gsm, where the mass ratio of the ES eccentric fibers, bamboo fibers, and profiled-section polyester fibers is 8:3:1; (3) Preparation of the highly permeable sanitary product containing eccentric fibers The highly permeable non-woven fabric is used as the surface layer material of the sanitary product, and according to the production method of the sanitary product, a highly permeable sanitary product containing eccentric fibers is obtained. Example 2

[0042] A highly permeable sanitary product containing eccentric fibers, which is different from Example 1 in that the raw materials and their dosages are as shown in Table 1. The mass ratio of the cortical material and the core material in the ES eccentric fibers is 1:1, and the mass ratio of the ES eccentric fibers, bamboo fibers, and profiled-section polyester fibers in the highly permeable non-woven fabric is 10:2:1. Other steps are the same as those in Example 1. Example 3

[0043] A highly permeable sanitary product containing eccentric fibers, which is different from Example 1 in that the raw materials and their dosages are as shown in Table 1. The mass ratio of the cortical material and the core material in the ES eccentric fibers is 1.1:1, and the mass ratio of the ES eccentric fibers, bamboo fibers, and profiled-section polyester fibers in the highly permeable non-woven fabric is 9:4:1. Other steps are the same as those in Example 1. Example 4

[0044] A highly permeable sanitary product containing eccentric fibers, which is different from Example 1 in that the raw materials and their dosages are as shown in Table 1. The mass ratio of the cortical material and the core material in the ES eccentric fibers is 1.2:1, and the mass ratio of the ES eccentric fibers, bamboo fibers, and profiled-section polyester fibers in the highly permeable non-woven fabric is 8:2:1. Other steps are the same as those in Example 1. Example 5

[0045] A highly permeable sanitary product containing eccentric fibers, which is different from Example 1 in that the composite microspheres in the raw material of the ES eccentric fiber core layer are obtained from Preparation Example 2, and the other steps are the same as those in Example 1. Example 6

[0046] A highly permeable sanitary product containing eccentric fibers, which is different from Example 1 in that the composite microspheres in the raw material of the ES eccentric fiber core layer are obtained from Preparation Example 3, and the other steps are the same as those in Example 1. Example 7

[0047] A highly permeable sanitary product containing eccentric fibers, which is different from Example 1 in that the composite microspheres in the raw material of the ES eccentric fiber core layer are obtained from Preparation Example 4, and the other steps are the same as those in Example 1. Example 8

[0048] A highly permeable sanitary product containing eccentric fibers, which is different from Example 1 in that the preparation method of PE grafted with acrylic acid in the ES eccentric fiber raw material includes the following steps: Using LDPE as the matrix resin, acrylic acid as the graft monomer, and dicumyl peroxide as the initiator. The dosage of the graft monomer is 8% of the LDPE matrix resin, and the dosage of the initiator is 0.5% of the HDPE matrix resin. Add the matrix resin, graft monomer, and initiator to a low-speed mixer in sequence, mix at a rotation speed of 120 r / min for 3 min, and then perform extrusion granulation and drying with a screw extruder to obtain PE grafted with acrylic acid. The temperatures of each zone of the screw extruder are: Zone 1 170 °C, Zone 2 175 °C, Zone 3 175 °C, Zone 4 180 °C, Zone 5 180 °C, Zone 6 175 °C, and the other steps are the same as those in Example ①. Example 9

[0049] A highly permeable sanitary product containing eccentric fibers, which is different from Example 1 in that graphene oxide is pretreated before being mixed with raw materials such as PE resin and PE grafted with acrylic acid: Disperse graphene oxide in water to form a graphene oxide dispersion liquid, dissolve chitosan quaternary ammonium salt in water, adjust the pH to 5.2 to form a surface treatment liquid, mix the graphene oxide dispersion liquid with the surface treatment liquid to form a blend. The mass ratio of graphene oxide, chitosan quaternary ammonium salt, and water in the blend is 1:8:30. After heating and stirring the reaction, filter, wash, and dry to obtain pretreated graphene oxide, and the other steps are the same as those in Example 1. Example 10

[0050] A highly permeable sanitary product containing eccentric fibers, which is different from Example 1 in that graphene oxide is pretreated as follows before being mixed with raw materials such as PE resin and PE grafted acrylic acid: Disperse graphene oxide in water to form a graphene oxide dispersion, dissolve chitosan quaternary ammonium salt in water, adjust the pH to 5 to form a surface treatment solution, mix the graphene oxide dispersion with the surface treatment solution to form a blend, and the mass ratio of graphene oxide, chitosan quaternary ammonium salt and water in the blend is 1:9:30. After heating and stirring the reaction, filter, wash and dry to obtain pretreated graphene oxide. Other steps are the same as in Example 1. Example 11

[0051] A highly permeable sanitary product containing eccentric fibers, which is different from Example 1 in that graphene oxide is pretreated as follows before being mixed with raw materials such as PE resin and PE grafted acrylic acid: Disperse graphene oxide in water to form a graphene oxide dispersion, dissolve chitosan quaternary ammonium salt in water, adjust the pH to 4.8 to form a surface treatment solution, mix the graphene oxide dispersion with the surface treatment solution to form a blend, and the mass ratio of graphene oxide, chitosan quaternary ammonium salt and water in the blend is 1:10:30. After heating and stirring the reaction, filter, wash and dry to obtain pretreated graphene oxide. Other steps are the same as in Example 1. Example 12

[0052] A highly permeable sanitary product containing eccentric fibers, which is different from Example 1 in that the high-permeability non-woven fabric does not contain profiled-section polyester fibers, and the profiled-section polyester fibers in the raw materials of the high-permeability non-woven fabric in Example 1 are replaced with an equal mass of ES eccentric fibers. Other steps are the same as in Example 1. Comparative example

[0053] Comparative example 1 A highly permeable sanitary product containing eccentric fibers, which is different from Example 1 in that the PE resin in the ES eccentric fiber cortex raw material is HDPE resin. Other steps are the same as in Example 1.

[0054] Comparative example 2 A highly permeable sanitary product containing eccentric fibers, which is different from Example 1 in that the ES eccentric fiber cortex raw material does not contain PE grafted acrylic acid, and the PE grafted acrylic acid in the raw materials is replaced with an equal mass of LDPE resin. Other steps are the same as in Example 1.

[0055] Comparative example 3 A highly permeable sanitary product containing eccentric fibers, which is different from Example 1 in that the cortical raw material of the ES eccentric fiber does not contain graphene oxide, and the graphene oxide in the raw material is replaced with an equal mass of LDPE resin, and other steps are the same as those in Example 1.

[0056] Comparative Example 4 A highly permeable sanitary product containing eccentric fibers, which is different from Example 1 in that the core layer raw material of the ES eccentric fiber does not contain hyperbranched polyester, and the carboxyl-terminated hyperbranched polyester in the raw material is replaced with an equal mass of PET resin, and other steps are the same as those in Example 1.

[0057] Comparative Example 5 A highly permeable sanitary product containing eccentric fibers, which is different from Example 1 in that the core layer raw material of the ES eccentric fiber does not contain hyperbranched polyester, and the carboxyl-terminated hyperbranched polyester in the raw material is replaced with an equal mass of linear carboxyl-terminated polyester (acid value is 60mgKOH / g, average molecular weight is 3000g / mol), and other steps are the same as those in Example 1.

[0058] Comparative Example 6 A highly permeable sanitary product containing eccentric fibers, which is different from Example 1 in that the core layer raw material of the ES eccentric fiber does not contain composite microspheres, and the composite microspheres in the raw material are replaced with an equal mass of PET resin, and other steps are the same as those in Example 1.

[0059] Comparative Example 7 A highly permeable sanitary product containing eccentric fibers, which is different from Example 1 in that the high-permeability non-woven fabric does not contain ES eccentric fibers, and the ES eccentric fibers in the raw material of the high-permeability non-woven fabric in Example 1 are replaced with an equal mass of bamboo fibers, and other steps are the same as those in Example 1. Performance detection test Test Example 1

[0060] The following relevant performance detection tests are carried out on the ES eccentric fibers obtained in step (1) of Examples 1-11 and Comparative Examples 1-6. Each group of tests is carried out 3 times. After calculating the test results, the average value is calculated as the final result and the final result is recorded in Table 2.

[0061] 1. Tensile strength: Referring to the relevant method regulations of GB / T14337-2008 "Test Method for Tensile Properties of Chemical Fiber Staple Fibers", the dry tensile strength and wet tensile strength of the ES eccentric fibers are detected; 2. Capillary rise height: Using an LFY-215 fabric capillary effect tester, the capillary rise height of the ES eccentric fibers is tested. The ES eccentric fibers are fixed on the instrument, water is added to the water tank, and the test time is 30 min; 3. Antibacterial rate: The test was conducted in accordance with GB15979-2002 "Hygiene Standard for Disposable Sanitary Products", and the test bacteria was Staphylococcus aureus (ATCC6538).

[0062] Table 2

[0063] According to the test results of the dry and wet breaking strength, wicking height and antibacterial performance of the ES eccentric fiber in Table 2, it can be seen that the ES eccentric fiber made of a PE cortex containing graphene oxide and a PET core layer containing highly absorbent hollow porous composite microspheres in this application can achieve high absorption and diffusion storage of liquid after absorbing liquid. It effectively improves the water absorption and permeability of the ES eccentric fiber while retaining the good mechanical properties of the ES eccentric fiber, and can still maintain good breaking strength after absorbing liquid, breaking the limitations of traditional ES eccentric fibers in subsequent applications caused by insufficient hydrophilicity, and opening up a broader market for the application of ES eccentric fibers in the field of sanitary products.

[0064] According to the performance test results of Examples 1-7 and Comparative Example 6, it can be seen that the composite microspheres made of carboxyl-terminated hyperbranched polyester as the core and polyvinyl alcohol as the shell are added to the core layer raw materials. By utilizing its hydrophilicity and hollow porous structure, the ES eccentric fiber can achieve efficient liquid absorption, penetration and storage. The expansion of the hollow porous structure after absorbing liquid can further open the fiber pores, forming a secondary diversion effect, further enhancing the liquid absorption, diffusion and storage capacity of the ES eccentric fiber, and locking in moisture. Furthermore, the composite microspheres achieve structural stability through cross-linking, which also has a significant effect on maintaining the mechanical properties of the ES eccentric fiber. The composite microspheres in Example 7 are prepared from carboxyl-terminated polyester and PVA. Experiments have shown that the liquid absorption, diffusion and liquid storage capabilities of the prepared fibers are significantly reduced. This is because the carboxyl-terminated polyester has fewer hydrophilic groups than the carboxyl-terminated hyperbranched polyester, which results in a relatively weak binding effect on the organic solvent during the preparation of the composite microspheres. When the organic solvent diffuses into the water, it is difficult to effectively form a hollow porous structure but a solid structure is formed. This seriously reduces the liquid absorption and storage capacity of the composite microspheres and limits the liquid absorption, diffusion and liquid storage capabilities of the ES eccentric core fiber.

[0065] From the performance test results of Example 1 and Comparative Examples 4-5, it can be seen that the use of carboxyl-terminated hyperbranched polyester significantly improves the liquid absorption and storage capacity of the fiber. This is because the highly branched molecular chain structure and the hollow porous structure of the composite microspheres can form a gradient diversion network. The strong water absorption of the fiber core layer promotes the speed of liquid absorption and penetration from the cortex to the core layer, quickly stores and laterally diffuses, avoiding the penetration blockage caused by local saturation. The hollow porous composite microspheres can further expand after liquid absorption, expanding the internal pores of the core layer and providing a larger liquid storage capacity space, significantly enhancing the liquid absorption and storage capacity of the ES eccentric fiber. However, the end carboxyl polyester does not have a highly branched molecular chain structure. After the fiber absorbs liquid, when the local liquid is saturated, its ability to diffuse and divert the liquid is insufficient, thus limiting the liquid absorption and storage capacity of the fiber.

[0066] From the performance test results of Example 1, Example 8 and Comparative Examples 1-2, it can be seen that Example 8 only uses the LDPE system. Although it can obtain better liquid absorption effect, it seriously sacrifices the mechanical properties. Comparative Example 1 only uses the LEPE system. Although the mechanical properties are better, it will affect the liquid absorption ability of the fiber. In this application, the use ratio of HDPE and LDPE is optimized. By grafting acrylic acid onto HDPE, the hydrophilicity of HDPE is improved, and at the same time, the toughened structure of HDPE is optimized, making the fiber as a whole softer while ensuring excellent mechanical properties.

[0067] From the performance test results of Example 1, Example 9-11 and Comparative Example 3, it can be seen that chitosan quaternary ammonium salt is cationically modified by adsorbing on the surface of graphene oxide. The quaternary ammonium groups can form chemical bond interactions with the carboxyl groups of PE grafted with acrylic acid and the carboxyl groups of the core layer end carboxyl hyperbranched polyester, effectively promoting the dispersion uniformity of graphene oxide in the cortex raw material, enabling the lamellar structure of graphene oxide to promote the liquid absorption and diffusion ability of the fiber, and at the same time enhancing the interfacial bonding ability between graphene oxide and the PE matrix, as well as between the cortex and the core layer, thereby further improving the hydrophilicity and mechanical properties of the fiber. Test Example 2

[0068] Perform the following relevant performance detection tests on the highly permeable non-woven fabrics obtained in step (2) of Examples 1-12 and Comparative Examples 1-7. Each group of tests is carried out 3 times. After calculating the test results, calculate the average value as the final result and record the final result in Table 3.

[0069] 1. Liquid penetration time: GB / T 24218.13-2010 Textiles - Test methods for non-woven fabrics - Part 8: Determination of liquid penetration time (simulating urine) to determine the primary liquid penetration time of the highly permeable non-woven fabric. Use a vernier caliper to measure the longest length of the liquid diffusing laterally along the diffusion center on the surface of the highly permeable non-woven fabric as the liquid penetration diffusion length; 2. Liquid retention rate: Cut the high-permeability non-woven fabric into pieces with a size of 2 cm × 2 cm. Weigh the cut samples and record it as W1. Then, condition the samples in a standard environment with a temperature of 20 ± 2°C and a humidity of 65 ± 5% for 24 hours to ensure the moisture content of the samples is stable. Conduct a centrifugation test on the fabric pieces. Centrifuge at a speed of 200 r / min for 1 minute to ensure that the liquid in the non-woven fabric samples does not drip freely. Then weigh and record it as W2. Calculate the liquid retention rate according to the formula: liquid retention rate = W2 / W1 × 100%. Table 3

[0070] From the performance test results in Table 3, it can be seen that the high-permeability non-woven fabric made of the ES eccentric fiber, profiled-section fiber, and bamboo fiber of the present application has the abilities of efficient liquid absorption, rapid penetration, and efficient liquid storage, and has great application potential in the field of sanitary products. Especially when used as the surface layer material of sanitary products, it can quickly penetrate and absorb after liquid absorption, and spread horizontally, effectively preventing the phenomenon of local liquid accumulation, reducing the problem of liquid backflow, effectively reducing the problem of liquid retention on the surface of sanitary products during use and the resulting side leakage due to the inability to quickly absorb liquid, and improving the comfort of using sanitary products.

[0071] From the performance test results of Examples 1-6, Example 12, and Comparative Example 7, it can be seen that when the ES eccentric fiber of the present application is used to prepare the surface layer non-woven fabric of sanitary products, it can significantly improve the liquid absorption permeability and liquid storage capacity of the non-woven fabric. Blending a small amount of profiled-section polyester fiber in the ES eccentric fiber can further increase the pores between the non-woven fabric fibers, form a three-dimensional diversion channel to assist in diversion. When the non-woven fabric absorbs liquid, it can quickly spread the liquid in the surface layer and then be absorbed and stored by the ES eccentric fiber, further improving the liquid absorption and penetration speed of the non-woven fabric, effectively preventing the problem of local liquid accumulation, reducing the problems of liquid backflow and side leakage caused by the inability to quickly absorb liquid, and improving the comfort of using sanitary products.

[0072] From the performance test results of Example 1 and Comparative Examples 1-6, it can be seen that when the ES eccentric fiber is used to prepare the high-permeability non-woven fabric, the influence of the liquid absorption, penetration, and liquid storage capabilities of the core layer raw material on the fiber is greater than that of the skin layer raw material.

[0073] From the performance test results of Example 1, Example 7 and Comparative Examples 4-6, it can be seen that the addition of ES eccentric fibers made of hollow porous microspheres with carboxyl-terminated hyperbranched polyester as the core and polyvinyl alcohol as the shell endows the non-woven fabric with stronger liquid storage and rapid penetration capabilities. Both carboxyl-terminated hyperbranched polyester and polyvinyl alcohol are highly water-absorbent substances, which can reduce the penetration resistance of water. The hollow porous structure and the highly branched molecular chain structure of hyperbranched polyester work together to form a gradient diversion network inside the non-woven fabric. The strong water absorption of the fiber core layer promotes the speed of liquid absorption and penetration from the skin layer to the core layer. After the liquid penetrates into the core layer, it can achieve rapid lateral diffusion under the action of the gradient diversion network in the core layer, avoiding the penetration blockage caused by local saturation and optimizing the uniformity of liquid distribution. When the hollow porous composite microspheres absorb liquid, they quickly attract water molecules into the internal pores of the composite microspheres and then further expand, enlarging the internal pores of the core layer, forming a secondary diversion effect, providing a larger liquid storage capacity space, and further enhancing the lateral diffusion ability of the non-woven fabric after liquid absorption. In Example 7, it is difficult to effectively form a hollow porous structure but a solid structure, which seriously reduces the liquid absorption and storage capacity of the composite microspheres and limits the liquid absorption diffusion and storage capacity of the non-woven fabric surface layer prepared by ES eccentric fibers.

[0074] From the performance test results of Example 1, Example 8 and Comparative Examples 1-2, it can be seen that by selecting high-density HDPE for grafting acrylic acid and then mixing it with low-density LDPE as the matrix of the skin layer, the balance between the mechanical stability and hydrophilic permeability of the skin layer is achieved, preventing the problem of skin layer cracking, ensuring the washing liquid penetration ability and excellent mechanical properties of the highly permeable non-woven fabric prepared by ES eccentric fibers, and at the same time maintaining the soft comfort of ES eccentric fibers.

[0075] From the performance test results of Example 1, Examples 9-11 and Comparative Example 3, it can be seen that the addition of graphene oxide utilizes the hydrophilicity and lamellar structure of graphene oxide to effectively promote the hydrophilic water absorption ability of the non-woven fabric. After absorbing liquid, it quickly penetrates along the graphene oxide to the fiber core layer for liquid storage. Chitosan quaternary ammonium salt is cationically modified by adsorbing on the surface of graphene oxide. The quaternary ammonium group can form a chemical bond interaction with the carboxyl group of PE grafted acrylic acid and the carboxyl group of the core layer carboxyl-terminated hyperbranched polyester, effectively promoting the dispersion uniformity of graphene oxide in the skin layer raw material, enhancing the interfacial bonding ability between graphene oxide and the PE matrix, as well as between the skin layer and the core layer, and maintaining the structural stability of the fiber when the hollow porous microspheres in the inner layer of the ES eccentric fiber absorb liquid and expand, and further storing liquid in the voids generated by the expansion.

[0076] This specific embodiment is only an interpretation of the present application and does not limit the present application. After reading this specification, those skilled in the art can make modifications to this embodiment that do not contribute creatively as needed, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A high-permeability sanitary product comprising eccentric fibers, characterized in that: The invention comprises a high-permeability non-woven fabric, which comprises ES eccentric fibers with a sheath-core bicomponent structure. The sheath raw materials of the ES eccentric fibers comprise 30-50 parts of PE resin, 25-40 parts of PE grafted acrylic acid, and 8-13 parts of graphene oxide, respectively, and the core raw materials of the ES eccentric fibers comprise 45-65 parts of PET resin, 15-25 parts of hyperbranched polyester, and 15-25 parts of composite microspheres, respectively, based on weight parts.

2. The high-permeability sanitary product comprising eccentric fibers according to claim 1, characterized in that: The PE resin is LDPE, and the PE matrix resin in the PE grafted acrylic acid is HDPE.

3. The high permeability sanitary product comprising eccentric fibers according to claim 1, characterized in that: The hyperbranched polyester is a carboxyl-terminated hyperbranched polyester.

4. The high permeability sanitary product comprising eccentric fibers according to claim 1, characterized in that: The composite microspheres are hollow porous microspheres made of carboxyl-terminated hyperbranched polyester as the core and polyvinyl alcohol as the shell.

5. The high permeability sanitary product comprising eccentric fibers according to claim 4, characterized in that: The preparation method of the composite microspheres comprises the following steps: The carboxyl-terminated hyperbranched polyester was dissolved in tetrahydrofuran to prepare a solution A with a concentration of 20-22 mg / mL, and polyvinyl alcohol was dissolved in water to prepare a solution B with a concentration of 3-4 mg / mL; Solution A and solution B were mixed with water, stirred for reaction, and then centrifuged and washed to obtain prefabricated microspheres, which were then dispersed in MES buffer, a cross-linking agent was added, stirred for reaction at room temperature, centrifuged and washed, and then freeze-dried to obtain hollow porous composite microspheres.

6. The high permeability sanitary product comprising eccentric fibers according to claim 5, characterized in that: The cross-linking agent is carbodiimide and N-hydroxysuccinimide in a mass ratio of 1:(0.8-1).

7. The high permeability sanitary product comprising eccentric fibers according to claim 1, characterized in that: The high-permeability non-woven fabric also includes bamboo fiber and special-shaped cross-section polyester fiber, and the mass ratio of the ES eccentric fiber, bamboo fiber and special-shaped cross-section polyester fiber is (8-10):(2-4):

1.

8. A method for preparing a high-permeability sanitary product comprising eccentric fibers according to any one of claims 1 to 7, characterized in that: The following steps are involved: PE resin, PE grafted acrylic acid and graphene oxide are mixed and melt-extruded to obtain a skin material; PET resin, hyperbranched polyester and composite microspheres are mixed and melt-extruded to obtain a core material; the skin material and the core material are composite-spun in a mass ratio of (1-1.2):1, wound, bundled, stretched, heat-set, curled and cut to obtain ES eccentric core fibers; The ES eccentric fiber and the special-shaped cross-section polyester fiber are opened, mixed, carded, cross-lapped and drawn to obtain a first fiber web; the bamboo fiber is opened, carded, cross-lapped and drawn to obtain a second fiber web; the first fiber web is placed on top and the second fiber web is placed on the bottom, and the two are hydroentangled and overlapped to form a whole, and then dried to obtain a high-permeability non-woven fabric; High-permeability nonwoven fabric is used as the surface material of sanitary products, and according to the production method of sanitary products, high-permeability sanitary products containing eccentric fibers are obtained.

9. The method for preparing a high-permeability sanitary product comprising eccentric fibers according to claim 8, characterized in that: The graphene oxide is pretreated as follows before being mixed with raw materials such as PE resin and PE grafted acrylic acid: the graphene oxide is dispersed in water to form a graphene oxide dispersion; chitosan quaternary ammonium salt is dissolved in water and the pH is adjusted to 4.8-5.2 to form a surface treatment liquid; the graphene oxide dispersion and the surface treatment liquid are mixed to form a blend, wherein the mass ratio of graphene oxide to chitosan quaternary ammonium salt in the blend is 1:(8-10); after heating and stirring for reaction, the pretreated graphene oxide is filtered, washed, and dried.

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