High-permeability sanitary product containing eccentric fiber and preparation method thereof

Abstract

The present application relates to the technical field of sanitary products, and specifically discloses a high-permeability sanitary product comprising eccentric fibers and a preparation method thereof. A high-permeability sanitary product comprising eccentric fibers, comprising a high-permeability non-woven fabric, wherein the high-permeability non-woven fabric comprises an ES eccentric fiber with a skin-core bicomponent structure; in parts by weight, the raw material of the cortex of the ES eccentric fiber comprises 30-50 parts of PE resin, 25-40 parts of PE grafted acrylic acid, and 8-13 parts of graphene oxide; the raw material of the core layer of the ES eccentric fiber comprises 45-65 parts of PET resin, 15-25 parts of hyperbranched polyester, and 15-25 parts of composite microspheres. The high-permeability sanitary product comprising eccentric fibers of the present application significantly improves the liquid absorption and penetration capacity while maintaining the original excellent mechanical properties, further improving the softness and comfort of the sanitary product.

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:

[0007] 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;

[0008] 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;

[0009] The core layer raw materials of the ES eccentric core fiber include 45-65 parts of PET resin, 15-25 parts of hyperbranched polyester and 15-25 parts of composite microspheres.

[0010] The non-woven fabric is prepared using an ES eccentric fiber structure. The surface hydrophilicity of the PE cortex is significantly enhanced by adding graphene oxide and grafted acrylic acid to the PE matrix. Under the action of the graphene oxide lamellar structure, the liquid can quickly penetrate into the core layer to achieve rapid diversion.

[0011] The core layer of the ES eccentric fiber is made of hyperbranched polyester and composite microspheres with a hollow porous structure. The highly branched molecular chain structure of the 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 of the cortex into 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 of the core layer, avoiding penetration blockage caused by local saturation and optimizing the uniformity of liquid distribution. The hollow porous composite microspheres can further expand after absorbing liquid, expand the internal pores of the core layer, provide a larger liquid storage capacity space, and significantly enhance the liquid absorption, penetration and storage capacity of the ES eccentric fiber.

[0012] By adopting the above technical solution, the water absorption and penetration limitations of traditional PE-PET eccentric core fibers are effectively improved. While retaining the softness, comfort and excellent mechanical properties of ES eccentric core fibers, it can quickly absorb liquid and penetrate into the core layer for storage, preventing liquid from being retained on the surface and side leakage caused by inability to quickly penetrate and absorb. It can keep the surface of sanitary products dry and improve the comfort of use of sanitary products.

[0013] Optionally, the PE resin is LDPE, and the PE matrix resin in the PE grafted acrylic acid is HDPE.

[0014] LDPE has the characteristics of low crystallinity and high flexibility, and can form a looser entanglement network during the fiber molding process, giving the ES eccentric fiber good softness and comfort. The high density of HDPE can provide rigid support for the grafted acrylic acid, preventing collapse and deformation caused by excessive softening. The wettability of the PE cortex is enhanced after acrylic acid grafting modification, which effectively reduces the resistance of the ES eccentric fiber to water absorption, and realizes the rapid water absorption of the ES eccentric fiber and the penetration of liquid into the core layer.

[0015] By adopting the above technical solution, high-density HDPE is selected for grafting with acrylic acid and then mixed with low-density LDPE as the matrix of the cortex, achieving a balance between the mechanical stability of the cortex and the hydrophilic permeability, preventing the problem of cortex cracking, while maintaining the softness and comfort of the ES eccentric core fiber.

[0016] Optionally, the hyperbranched polyester is a carboxyl-terminated hyperbranched polyester.

[0017] The carboxyl-terminated hyperbranched polyester has strong hydrophilicity and good compatibility with the PET matrix. It can significantly reduce the contact angle of the fiber core layer and enhance the fiber's liquid absorption capacity. The hyperbranched polyester molecular structure has a high degree of branching and low entanglement three-dimensional structure, which can form a large number of nano-micrometer-level pores in the PET core layer. The porosity can be further increased after liquid absorption, forming a dynamic liquid storage space.

[0018] By adopting the above technical solution, the selection of end-carboxyl 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 weak water absorption of the PET core layer, and enhance the water absorption and permeability of the ES eccentric fiber.

[0019] Optionally, the composite microspheres are hollow porous microspheres made of carboxyl-terminated hyperbranched polyester as the core and polyvinyl alcohol as the shell.

[0020] Optionally, the method for preparing the composite microspheres comprises the following steps:

[0021] 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;

[0022] 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.

[0023] Optionally, the cross-linking agent is carbodiimide and N-hydroxysuccinimide in a mass ratio of 1:(0.8-1).

[0024] Tetrahydrofuran, as an organic solvent, has good solubility for both carboxyl-terminated hyperbranched polyesters and polyvinyl alcohol. When solution A is used as the dispersed phase and solution B is used as the continuous phase, through the solvent volatilization method, as the tetrahydrofuran slowly evaporates, the tetrahydrofuran inside the core layer diffuses outward at a rate faster than the external solvent is replenished, resulting in the formation of a depletion zone at the center of the core layer, thereby forming a hollow structure. The solubility of the carboxyl-terminated hyperbranched polyester in the mixed solution decreases, triggering progressive phase separation. During this process, on the one hand, droplet shapes are formed, and polyvinyl alcohol is preferentially enriched on the droplet surface to form core-shell microspheres. On the other hand, a microphase-separated network structure is formed within the polymer. After the organic solvent evaporates, pores are left, forming a hollow porous microsphere structure.

[0025] Carboxyl-terminated hyperbranched polyester and polyvinyl alcohol are both highly water-absorbing substances that can reduce the penetration resistance of water. When absorbing liquid, they can quickly attract water molecules into the internal pores of the composite microspheres. The hollow and porous structure provides a diffusion path for water molecules, giving the composite microspheres strong water absorption and permeability properties.

[0026] Furthermore, the composite microspheres were cross-linked using the EDC / NHS system. EDC first reacted with the carboxyl group to form a highly active O-acylisourea intermediate, and then formed a stable NHS ester with NHS, achieving a strong chemical bond between the hyperbranched polyester and polyvinyl alcohol, and preferentially improving the mechanical properties and processing resistance of the composite microspheres. The cross-linked network can prevent the composite microspheres from being damaged during the subsequent spinning process, and can also prevent the composite microspheres from excessively swelling after absorbing water, thereby maintaining structural integrity, maintaining the pore structure, and ensuring rapid penetration of liquids.

[0027] By adopting the above technical solution, hollow porous microspheres made of carboxyl-terminated hyperbranched polyester as the core and polyvinyl alcohol as the shell, as the core layer material, can achieve high-efficiency liquid storage. The hollow structure of the microspheres expands after absorbing liquid, further opening the pores of the fiber, forming a secondary diversion effect, and further enhancing the fiber's liquid absorption, penetration and liquid storage capacity.

[0028] Optionally, the high-permeability non-woven fabric further comprises bamboo fiber and special-section polyester fiber, and the mass ratio of the ES eccentric fiber, bamboo fiber and special-section polyester fiber is (8-10):(2-4):1.

[0029] Optionally, the cross-sectional shape of the special-shaped cross-sectional polyester fiber is cross-shaped or Y-shaped.

[0030] By adopting the above technical solution, with ES eccentric fiber as the main body, bamboo fiber supplementing hydrophilicity and soft antibacterial properties, and blending a small amount of special-section polyester fiber, the pores between the non-woven fabric fibers can be significantly increased to form a three-dimensional diversion channel to assist in diversion. When the non-woven fabric absorbs liquid, the liquid can be quickly diffused and spread in the surface layer and then absorbed and stored by the ES eccentric fiber, thereby improving the liquid absorption and penetration capacity of the non-woven fabric, effectively preventing local liquid accumulation problems, reducing liquid reverse osmosis and side leakage problems caused by inability to absorb liquid quickly, and improving the comfort of sanitary products.

[0031] In a second aspect, the present application provides a method for preparing a high-permeability sanitary product comprising eccentric fibers, using the following technical solution:

[0032] A method for preparing a high-permeability sanitary product containing eccentric fibers comprises the following steps:

[0033] 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;

[0034] 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;

[0035] 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.

[0036] By adopting the above technical scheme, the ES eccentric fibers and the special-section polyester fibers are opened, mixed, combed, cross-laid, and stretched to obtain a first fiber web as the upper layer for hydroentanglement of the non-woven fabric, so that the surface layer has hydrophilicity. When absorbing liquid, it can quickly diffuse and spread the liquid laterally with the assistance of a small amount of special-section polyester fibers. The hydrophilicity of the ES eccentric fiber cortex leads to rapid liquid absorption and penetration into the ES eccentric fiber core layer, for liquid absorption, diffusion and storage; the second fiber web obtained by combing and laying bamboo fibers is used as the lower layer for hydroentanglement of the non-woven fabric. The natural hydrophilicity and antibacterial properties of the bamboo fibers further supplement the performance of the non-woven fabric surface layer, and enhance the liquid storage capacity of the non-woven fabric surface layer. When the prepared non-woven fabric is used as the surface material for preparing sanitary products, the liquid absorption permeability and efficient liquid storage capacity of the sanitary products are significantly improved, the water absorption capacity and mechanical properties of the sanitary products are balanced, and the softness and comfort of the sanitary products are further improved.

[0037] Optionally, the graphene oxide is subjected to the following pretreatment before being mixed with raw materials such as PE resin and PE grafted acrylic acid:

[0038] 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 mixture is filtered, washed, and dried to obtain pretreated graphene oxide.

[0039] By adopting the above technical solution, chitosan quaternary ammonium salt is cationic-modified by adsorption on the surface of graphene oxide. The quaternary ammonium group can form a chemical bond with the carboxyl group of PE grafted acrylic acid and the carboxyl group of the core-layer carboxyl-terminated hyperbranched polyester, which effectively promotes the dispersion uniformity of graphene oxide in the cortex raw material and enhances the interfacial bonding ability between graphene oxide and PE matrix, as well as between the cortex and core layer.

[0040] In summary, this application has the following beneficial effects:

[0041] 1. Since the ES eccentric fiber made of a PE sheath containing graphene oxide and a PET core layer containing highly absorbent hollow porous composite microspheres is used in this application, after absorbing liquid, the sheath layer can quickly guide the liquid to penetrate into the core layer, and the core layer absorbs liquid at a high capacity, thereby achieving high absorption, penetration and locking of the liquid, and effectively improving the water absorption and permeability of the ES eccentric fiber while retaining the good mechanical properties of the ES eccentric fiber.

[0042] 2. In the present application, hollow porous microspheres made of carboxyl-terminated hyperbranched polyester as the core and polyvinyl alcohol as the shell are preferably used. The hollow porous structure is formed by inducing phase separation by solvent volatilization, which can efficiently absorb liquid, penetrate and store it. The hollow porous structure expands after absorbing liquid and can further open the fiber pores to form a secondary diversion effect, further enhancing the liquid absorption, penetration and storage capacity of the ES eccentric core fiber and locking in moisture. The structural stabilization of the hollow porous microspheres is achieved through the cross-linking effect between the cross-linking agent and the carboxyl-terminated hyperbranched polyester and polyvinyl alcohol, thereby improving the dispersibility of the composite microspheres when mixed with other core layer raw materials and enhancing the structural stability of the hollow porous structure in the subsequent spinning process.

[0043] 3. The present application uses ES eccentric fiber, bamboo fiber and special-section polyester fiber as raw materials to prepare non-woven fabric as the surface material of sanitary products. After absorbing liquid, the special-section polyester fiber can form a three-dimensional diversion channel in the surface layer, quickly diffuse and spread the liquid in the surface layer, prevent local liquid accumulation, and reduce the occurrence of liquid reverse osmosis. The ES eccentric fiber takes the lead in accelerating the storage of liquid penetration, and the bamboo fiber further enhances the absorption and storage of liquid, effectively reducing the problem of liquid retention on the surface of sanitary products during use, which cannot be quickly absorbed and causes side leakage, thereby improving the comfort of sanitary products. DETAILED DESCRIPTION

[0044] The following examples further illustrate the present application in detail.

[0045] raw material

[0046] Unless otherwise specified, the raw materials used in the preparation examples, examples and comparative examples in this application are all commercially available products, specifically:

[0047] Bamboo fiber, filament, diameter 15±3mm, linear density 25±3tex;

[0048] Special-shaped cross-section polyester fiber, with a cross-section and specifications of 75D / 36F;

[0049] LDPE resin, selected from Yanshan Petrochemical, LD615;

[0050] HDPE resin, selected from Fushun Petrochemical, 2911;

[0051] Sodium polyacrylate, selected from Jiezhiyuan water treatment materials, J-SN513;

[0052] PET resin, with an intrinsic viscosity of 0.7-1 dL / g, was selected from Hengshui Jizhou District Qinghua Plastic Factory, with the product number PET-QH and the brand name Qh-pet;

[0053] Graphene oxide, selected from Zhejiang Zhiti Nano Micro New Materials Co., Ltd., DN-20DY;

[0054] Chitosan quaternary ammonium salt, selected from Shandong Weikang Biopharmaceutical Technology Co., Ltd., chitosan quaternary ammonium salt 01;

[0055] Carboxyl terminated hyperbranched polyester, selected from Wuhan Hyperbranched Resin Technology Co., Ltd., HyPer C302;

[0056] Polyvinyl alcohol, selected from Zhengzhou Yufan Biotechnology Co., Ltd., YF-H61;

[0057] EDC, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, was obtained from Shanghai Yuanye Biotechnology Co., Ltd., S30053;

[0058] N-hydroxysuccinimide (NHS) was selected from Shanghai Yuanye Biotechnology Co., Ltd., S20179.

[0059] Preparation example of composite microspheres

[0060] Preparation Example 1

[0061] The preparation method of composite microspheres comprises the following steps:

[0062] S1: The carboxyl-terminated hyperbranched polyester was dissolved in tetrahydrofuran to prepare a solution A with a concentration of 21.5 mg / mL, and polyvinyl alcohol was dissolved in deionized water to prepare a solution B with a concentration of 3 mg / mL;

[0063] S2: 1 mL of solution B was mixed with 30 mL of deionized water for dilution. 1 mL of solution A was added dropwise to the diluted solution B under stirring at a rate of 0.05 mL / s. Stirring was continued for 20 h to allow the tetrahydrofuran to gradually evaporate. After centrifugation and washing, hollow porous preformed microspheres with a carboxyl-terminated hyperbranched polyester as the core and polyvinyl alcohol as the shell were obtained.

[0064] S3: The prefabricated microspheres were dispersed in MES buffer, and carbodiimide and N-hydroxysuccinimide were added as cross-linkers in a mass ratio of 1:1. The amount of the cross-linker was 5.6% of the prefabricated microspheres. The mixture was stirred at room temperature for 10 h, centrifuged and washed, and then freeze-dried to obtain hollow porous composite microspheres.

[0065] Preparation Example 2

[0066] The preparation method of composite microspheres comprises the following steps:

[0067] S1: The carboxyl-terminated hyperbranched polyester was dissolved in tetrahydrofuran to prepare a solution A with a concentration of 22 mg / mL, and polyvinyl alcohol was dissolved in deionized water to prepare a solution B with a concentration of 4 mg / mL;

[0068] S2: 1 mL of solution B was mixed with 30 mL of deionized water for dilution. 1 mL of solution A was added dropwise to the diluted solution B under stirring at a rate of 0.05 mL / s. Stirring was continued for 20 h to allow the tetrahydrofuran to gradually evaporate. After centrifugation and washing, hollow porous preformed microspheres with a carboxyl-terminated hyperbranched polyester as the core and polyvinyl alcohol as the shell were obtained.

[0069] S3: The prefabricated microspheres were dispersed in MES buffer, and carbodiimide and N-hydroxysuccinimide were added as crosslinkers in a mass ratio of 1:0.9. The amount of the crosslinker was 5% of the mass of the prefabricated microspheres. The mixture was stirred at room temperature for 10 h, centrifuged and washed, and then freeze-dried to obtain hollow porous composite microspheres.

[0070] Preparation Example 3

[0071] The preparation method of composite microspheres comprises the following steps:

[0072] S1: dissolving the carboxyl-terminated hyperbranched polyester in tetrahydrofuran to prepare a solution A with a concentration of 20 mg / mL, and dissolving polyvinyl alcohol in deionized water to prepare a solution B with a concentration of 4 mg / mL;

[0073] S2: 1 mL of solution B was mixed with 30 mL of deionized water for dilution. 1 mL of solution A was added dropwise to the diluted solution B under stirring at a rate of 0.05 mL / s. Stirring was continued for 20 h to allow the tetrahydrofuran to gradually evaporate. After centrifugation and washing, hollow porous preformed microspheres with a carboxyl-terminated hyperbranched polyester as the core and polyvinyl alcohol as the shell were obtained.

[0074] S3: The prefabricated microspheres were dispersed in MES buffer, and carbodiimide and N-hydroxysuccinimide were added as cross-linkers in a mass ratio of 1:0.8. The amount of the cross-linker was 4.5% of the mass of the prefabricated microspheres. The mixture was stirred at room temperature for 10 h, centrifuged and washed, and then freeze-dried to obtain hollow porous composite microspheres.

[0075] Preparation Example 4

[0076] The preparation method of composite microspheres comprises the following steps:

[0077] S1: carboxyl-terminated polyester (acid value of 60 mgKOH / g, average molecular weight of 3000 g / mol) was dissolved in tetrahydrofuran to prepare solution A with a concentration of 21.5 mg / mL, and polyvinyl alcohol was dissolved in deionized water to prepare solution B with a concentration of 3 mg / mL;

[0078] S2: 1 mL of solution B was mixed with 30 mL of deionized water for dilution. 1 mL of solution A was added dropwise to the diluted solution B under stirring at a rate of 0.05 mL / s. Stirring was continued for 20 h to allow the tetrahydrofuran to gradually evaporate. After centrifugation and washing, prefabricated microspheres with a carboxyl-terminated polyester as the core and a polyvinyl alcohol as the shell were obtained.

[0079] S3: The prefabricated microspheres were dispersed in MES buffer, and carbodiimide and N-hydroxysuccinimide were added as crosslinkers in a mass ratio of 1:1. The amount of the crosslinker was 5.6% of the prefabricated microspheres. The microspheres were stirred at room temperature for 10 h, washed by centrifugation, and then freeze-dried to obtain composite microspheres. Example Example 1

[0080] A high-permeability sanitary product containing eccentric fibers includes a high-permeability non-woven fabric, wherein the high-permeability non-woven fabric is made of ES eccentric fibers, bamboo fibers, and special-section polyester fibers. The ES eccentric fibers have a core-skin bicomponent structure. The raw materials and amounts are shown in Table 1, wherein the PE resin is LDPE resin, the hyperbranched polyester is a carboxyl-terminated hyperbranched polyester, the composite microspheres are obtained by Preparation Example 1, and the dispersant is sodium polyacrylate.

[0081] Table 1

[0082]

[0083] The method for preparing the high-permeability sanitary product containing eccentric fibers comprises the following steps:

[0084] (1) Preparation of ES eccentric fibers

[0085] S1: HDPE is used as the base resin, acrylic acid is used as the grafting monomer, and dicumyl peroxide is used as the initiator. The amount of the grafting monomer is 8% of the HDPE base resin, and the amount of the initiator is 0.5% of the HDPE base resin. The base resin, grafting monomer, and initiator are sequentially added into a low-speed mixer, mixed at a speed of 120 r / min for 3 minutes, extruded and granulated using a screw extruder, and dried to obtain PE grafted acrylic acid. The temperatures of each zone of the screw extruder are: 170°C in zone 1, 175°C in zone 2, 175°C in zone 3, 180°C in zone 4, 180°C in zone 5, and 175°C in zone 6;

[0086] S2: PE resin, PE grafted acrylic acid, graphene oxide, antioxidant and dispersant are mixed and melted through a screw extruder to obtain a melt to prepare a skin material. The temperatures of each zone of the screw extruder are as follows: the temperatures of each zone of the screw extruder are: zone 1 200°C, zone 2 210°C, zone 3 220°C, zone 4 230°C, zone 5 235°C, zone 6 240°C;

[0087] S3: PET resin, hyperbranched polyester, composite microspheres and antioxidant are mixed and melted through a screw extruder to obtain a core layer material. The temperatures of each zone of the screw extruder are: 250° C. in zone 1, 255° C. in zone 2, 265° C. in zone 3, 275° C. in zone 4, 275° C. in zone 5, and 270° C. in zone 6.

[0088] S4: The skin material and the core material are composite spun in a mass ratio of 1:1, wound, bundled, stretched, heat-set, crimped, and cut to obtain ES eccentric core fiber, 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 crimping machine main pressure 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 stretching multiple is 3.6, the stretching 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;

[0089] (2) Preparation of high permeability non-woven fabrics

[0090] S1: ES eccentric fibers and special-shaped cross-section polyester fibers are opened, mixed, carded, cross-lapped, and drafted to obtain a first fiber web;

[0091] S2: opening, carding, cross-lapping and drafting the bamboo fibers to obtain a second fiber web;

[0092] S3: The first fiber web is on top and the second fiber web is on the bottom, which are hydroentangled and overlapped to form a whole. After drying, a high-permeability non-woven fabric with a gram weight of (40±2) gsm is obtained, wherein the mass ratio of ES eccentric core fiber, bamboo fiber and special-shaped cross-section polyester fiber is 8:3:1;

[0093] (3) Preparation of high-permeability sanitary products containing eccentric fibers

[0094] 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. Example 2

[0095] A high-permeability sanitary product comprising eccentric fibers is different from Example 1 in that the raw materials and amounts are as shown in Table 1, the mass ratio of the cortex material to the core material in the ES eccentric fibers is 1:1, the mass ratio of the ES eccentric fibers, bamboo fibers, and special-section polyester fibers in the high-permeability non-woven fabric is 10:2:1, and the other steps are the same as in Example 1. Example 3

[0096] A high-permeability sanitary product comprising eccentric fibers is different from Example 1 in that the raw materials and amounts are as shown in Table 1, the mass ratio of the cortex material to the core material in the ES eccentric fibers is 1.1:1, the mass ratio of the ES eccentric fibers, bamboo fibers, and special-section polyester fibers in the high-permeability non-woven fabric is 9:4:1, and the other steps are the same as in Example 1. Example 4

[0097] A high-permeability sanitary product comprising eccentric fibers is different from Example 1 in that the raw materials and amounts are as shown in Table 1, the mass ratio of the cortex material to the core material in the ES eccentric fibers is 1.2:1, the mass ratio of the ES eccentric fibers, bamboo fibers, and special-section polyester fibers in the high-permeability non-woven fabric is 8:2:1, and the other steps are the same as in Example 1. Example 5

[0098] A high-permeability sanitary product comprising eccentric fibers, which differs from Example 1 in that the composite microspheres in the ES eccentric fiber core layer raw material are obtained by Preparation Example 2, and the other steps are the same as Example 1. Example 6

[0099] A high-permeability sanitary product comprising eccentric fibers, which differs from Example 1 in that the composite microspheres in the ES eccentric fiber core layer raw material are obtained by Preparation Example 3, and the other steps are the same as Example 1. Example 7

[0100] A high-permeability sanitary product comprising eccentric fibers, which differs from Example 1 in that the composite microspheres in the ES eccentric fiber core layer raw material are obtained by Preparation Example 4, and the other steps are the same as Example 1. Example 8

[0101] A high-permeability sanitary product comprising eccentric fibers, which differs from Example 1 in that a method for preparing PE grafted acrylic acid in ES eccentric fiber raw materials comprises the following steps:

[0102] LDPE is used as the base resin, acrylic acid is used as the grafting monomer, and dicumyl peroxide is used as the initiator. The amount of the grafting monomer is 8% of the LDPE base resin, and the amount of the initiator is 0.5% of the HDPE base resin. The base resin, grafting monomer and initiator are added to a low-speed mixer in sequence, mixed at a speed of 120 r / min for 3 minutes, extruded and granulated with a screw extruder, and dried to obtain PE grafted acrylic acid. The temperatures of each zone of the screw extruder are: 170°C in zone 1, 175°C in zone 2, 175°C in zone 3, 180°C in zone 4, 180°C in zone 5, and 175°C in zone 6. The other steps are the same as in Example 1. Example 9

[0103] A high-permeability sanitary product comprising eccentric fibers, which differs from Example 1 in that the graphene oxide is pretreated as follows before being mixed with raw materials such as PE resin and PE grafted acrylic acid:

[0104] 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 5.2 to form a surface treatment solution, and the graphene oxide dispersion and the surface treatment solution are mixed to form a blend, wherein the mass ratio of graphene oxide, chitosan quaternary ammonium salt and water in the blend is 1:8:30, and after heating and stirring to react, filtering, washing, and drying to obtain pretreated graphene oxide, the other steps are the same as in Example 1. Example 10

[0105] A high-permeability sanitary product comprising eccentric fibers, which differs from Example 1 in that the graphene oxide is pretreated as follows before being mixed with raw materials such as PE resin and PE grafted acrylic acid:

[0106] 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 5 to form a surface treatment solution, and the graphene oxide dispersion and the surface treatment solution are mixed to form a blend, wherein the mass ratio of graphene oxide, chitosan quaternary ammonium salt and water in the blend is 1:9:30, and after heating and stirring to react, filtering, washing, and drying to obtain pretreated graphene oxide, the other steps are the same as in Example 1. Example 11

[0107] A high-permeability sanitary product comprising eccentric fibers, which differs from Example 1 in that the graphene oxide is pretreated as follows before being mixed with raw materials such as PE resin and PE grafted acrylic acid:

[0108] 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 to form a surface treatment solution, and the graphene oxide dispersion and the surface treatment solution are mixed to form a blend, wherein the mass ratio of graphene oxide, chitosan quaternary ammonium salt and water in the blend is 1:10:30, and after heating and stirring the reaction, filtering, washing, and drying to obtain pretreated graphene oxide, the other steps are the same as in Example 1. Example 12

[0109] A high-permeability sanitary product containing eccentric fibers, which differs from Example 1 in that the high-permeability non-woven fabric does not contain special-shaped cross-section polyester fibers, and the special-shaped cross-section polyester fibers used as raw materials of the high-permeability non-woven fabric in Example 1 are replaced with ES eccentric fibers of equal mass, and the other steps are the same as Example 1. Comparative Example

[0110] Comparative Example 1

[0111] A high-permeability sanitary product comprising eccentric fibers, which differs from Example 1 in that the PE resin in the raw material of the ES eccentric fiber skin layer is HDPE resin, and the other steps are the same as Example 1.

[0112] Comparative Example 2

[0113] A high-permeability sanitary product comprising eccentric fibers, which differs from Example 1 in that the raw material of the ES eccentric fiber cortex does not contain PE grafted acrylic acid, and the PE grafted acrylic acid in the raw material is replaced with LDPE resin of equal mass, and the other steps are the same as Example 1.

[0114] Comparative Example 3

[0115] A high-permeability sanitary product comprising eccentric fibers, which differs from Example 1 in that the raw material of the ES eccentric fiber cortex does not contain graphene oxide, and the graphene oxide in the raw material is replaced with LDPE resin of equal mass, and the other steps are the same as Example 1.

[0116] Comparative Example 4

[0117] A high-permeability sanitary product comprising eccentric fibers, which differs from Example 1 in that the raw material of the ES eccentric fiber core layer does not contain hyperbranched polyester, and the carboxyl-terminated hyperbranched polyester in the raw material is replaced with PET resin of equal mass, and the other steps are the same as Example 1.

[0118] Comparative Example 5

[0119] A high-permeability sanitary product comprising eccentric fibers, which differs from Example 1 in that the raw material of the ES eccentric fiber core layer does not contain hyperbranched polyester, and the carboxyl-terminated hyperbranched polyester in the raw material is replaced by an equal mass of linear carboxyl-terminated polyester (acid value of 60 mgKOH / g, average molecular weight of 3000 g / mol), and the other steps are the same as in Example 1.

[0120] Comparative Example 6

[0121] A high-permeability sanitary product comprising eccentric fibers, which differs from Example 1 in that the raw material of the ES eccentric fiber core layer does not contain composite microspheres, and the composite microspheres in the raw material are replaced with PET resin of equal mass, and the other steps are the same as Example 1.

[0122] Comparative Example 7

[0123] A high-permeability sanitary product containing eccentric fibers, which differs from Example 1 in that the high-permeability non-woven fabric does not contain ES eccentric fibers, the ES eccentric fibers used as raw materials of the high-permeability non-woven fabric in Example 1 are replaced with bamboo fibers of equal mass, and the other steps are the same as Example 1.

[0124] Performance testing

[0125] Test Example 1

[0126] The following relevant performance test tests were performed on the ES eccentric fibers obtained in step (1) of Examples 1-11 and Comparative Examples 1-6. Each test was performed 3 times. After calculating the test results, the average value was calculated as the final result and the final results were recorded in Table 2.

[0127] 1. Breaking strength: Refer to the relevant method provisions of GB / T14337-2008 "Test method for tensile properties of chemical staple fibers" to test the dry breaking strength and wet breaking strength of ES eccentric fibers;

[0128] 2. Wicking height: Use the LFY-215 fabric capillary effect tester to test the wicking height of the ES eccentric fiber. Fix the ES eccentric fiber on the instrument and add water to the water tank. The test time is 30 minutes.

[0129] 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).

[0130] Table 2

[0131]

[0132] 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.

[0133] 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.

[0134] According to 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 of the cortex to the core layer, quickly stores and diffuses laterally, and avoids penetration blockage caused by local saturation. The hollow porous composite microspheres can further expand after absorbing liquid, expand the internal pores of the core layer, and provide a larger liquid storage capacity space, which significantly enhances the liquid absorption and storage capacity of the ES eccentric core fiber. The terminal carboxyl polyester does not have a highly branched molecular chain structure. After the fiber absorbs liquid, when the liquid is locally saturated, the diffusion and diversion capacity of the liquid is insufficient, thereby limiting the liquid absorption and storage capacity of the fiber.

[0135] According to 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 achieve 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. The present application optimizes the usage ratio of HDPE and LDPE. By grafting acrylic acid on HDPE, the hydrophilicity of HDPE is improved and the tempered structure of HDPE is optimized, making the fiber as a whole softer while ensuring excellent mechanical properties.

[0136] According to the performance test results of Example 1, Examples 9-11 and Comparative Example 3, it can be seen that the chitosan quaternary ammonium salt is cationically modified by adsorption on the surface of graphene oxide, and the quaternary ammonium group can form a chemical bond with the carboxyl group of PE grafted acrylic acid and the carboxyl group of the core layer end carboxyl hyperbranched polyester, which effectively promotes the uniformity of dispersion of graphene oxide in the cortex raw material, so that the lamellar structure of graphene oxide can promote the liquid absorption and diffusion ability of the fiber, and at the same time enhances the interfacial bonding ability between graphene oxide and the PE matrix, and between the cortex and the core layer, thereby further improving the hydrophilicity and mechanical properties of the fiber.

[0137] Test Example 2

[0138] The following relevant performance test tests were performed on the high permeability non-woven fabrics obtained in step (2) of Examples 1-12 and Comparative Examples 1-7. Each test was performed 3 times. After calculating the test results, the average value was calculated as the final result and the final results were recorded in Table 3.

[0139] 1. Liquid penetration time: GB / T 24218.13-2010 Textiles / Nonwovens Test Methods - Part 8: Determination of Liquid Penetration Time (Simulated Urine) Determine the primary liquid penetration time of high-permeability nonwovens. Use a vernier caliper to measure the longest length of liquid diffusion along the diffusion center on the surface of the high-permeability nonwoven as the liquid penetration diffusion length;

[0140] 2. Liquid holdup: Cut the high-permeability non-woven fabric into 2cm×2cm pieces, weigh the cut sample and record it as W1. Then, condition the sample in a standard environment with a temperature of 20±2℃ and a humidity of 65±5% for 24 hours to ensure that the moisture content of the sample is stable. Centrifuge the sample at 200r / min for 1 minute to ensure that the liquid in the non-woven fabric sample does not drip freely. Then weigh it and record it as W2. Calculate the liquid holdup according to the formula: Liquid holdup = W2 / W1×100%.

[0141] Table 3

[0142]

[0143] According to the performance test results in Table 3, it can be seen that the high-permeability non-woven fabric made of ES eccentric core fiber, special-section fiber and bamboo fiber of the present application has the ability of efficient liquid absorption, rapid penetration and efficient liquid storage, and has huge application potential in the field of sanitary products, especially when used as the surface material of sanitary products. After absorbing the liquid, it can quickly penetrate and absorb, and diffuse laterally, which can effectively prevent local liquid accumulation and reduce the problem of liquid reverse osmosis. It effectively reduces the problem of liquid retention on the surface of sanitary products during use, which cannot be quickly absorbed and causes side leakage, thereby improving the comfort of sanitary products.

[0144] According to the performance test results of Examples 1-6, Example 12 and Comparative Example 7, it can be seen that the ES eccentric fibers of the present application can significantly improve the liquid absorption permeability and liquid storage capacity of the non-woven fabric when used to prepare the surface non-woven fabric of sanitary products. Blending a small amount of special-section polyester fibers into the ES eccentric fibers can further increase the pores between the non-woven fibers, forming a three-dimensional diversion channel to assist in diversion. When the non-woven fabric absorbs liquid, the liquid can be quickly diffused and spread in the surface layer and then absorbed and stored by the ES eccentric fibers, further improving the liquid absorption and penetration speed of the non-woven fabric, effectively preventing local liquid accumulation problems, reducing liquid reverse osmosis and side leakage problems caused by inability to absorb liquid quickly, and improving the comfort of use of sanitary products.

[0145] According to the performance test results of Example 1 and Comparative Examples 1-6, it can be seen that when ES eccentric core fibers are used to prepare high-permeability non-woven fabrics, the liquid absorption, penetration and storage capacity of the core layer raw materials have a greater impact on the fibers than the skin layer raw materials.

[0146] According to 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 makes the non-woven fabric have stronger liquid storage and rapid penetration capabilities. The carboxyl-terminated hyperbranched polyester and polyvinyl alcohol are both highly water-absorbing substances that can reduce the penetration resistance of water. The hollow porous structure cooperates with the highly branched molecular chain structure of the hyperbranched polyester 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 of the cortex into 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 of the core layer, avoiding penetration blockage caused by local saturation and optimizing the uniformity of liquid distribution. The hollow porous composite microspheres quickly attract water molecules into the internal pores of the composite microspheres during liquid absorption and then further expand, expanding the internal pores of the core layer, forming a secondary diversion effect, providing a larger liquid storage capacity space, and further enhancing the ability of the non-woven fabric to diffuse laterally after liquid absorption. In Example 7, it is difficult to effectively form a hollow porous structure but a solid structure is formed, which seriously reduces the liquid absorption and storage capacity of the composite microspheres and limits the liquid absorption, diffusion and storage capacity of the surface layer of the sanitary product non-woven fabric prepared from ES eccentric core fibers.

[0147] According to 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 with acrylic acid and then mixing it with low-density LDPE as the matrix of the cortex, a balance between the mechanical stability of the cortex and the hydrophilic permeability is achieved, the problem of cortex cracking is prevented, and the detergent penetration ability and excellent mechanical properties of the high-permeability non-woven fabric prepared by ES eccentric core fibers are ensured, while maintaining the softness and comfort of the ES eccentric core fibers.

[0148] According to 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, effectively promoting the hydrophilic water absorption capacity of the non-woven fabric, and after imbibing, the non-woven fabric quickly penetrates into the fiber core layer along the graphene oxide for liquid storage. The chitosan quaternary ammonium salt is cationically modified by adsorption on the surface of the graphene oxide. The quaternary ammonium group can form a chemical bond with the carboxyl group of the PE grafted acrylic acid and the carboxyl group of the core layer carboxyl-terminated hyperbranched polyester, effectively promoting the dispersion uniformity of the graphene oxide in the cortex raw material, enhancing the interfacial bonding ability between the graphene oxide and the PE matrix, and between the cortex and the core layer, maintaining the structural stability of the fiber when the hollow porous microspheres in the inner layer of the ES eccentric fiber absorb and expand, and then further storing liquid in the gap generated by the expansion.

[0149] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are 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 core-skin bicomponent structure. The raw materials of the skin layer 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, in parts by weight. The raw materials of the core layer of the ES eccentric fibers comprise 45-65 parts of PET resin, 15-25 parts of carboxyl-terminated hyperbranched polyester, and 15-25 parts of composite microspheres. The PE resin is LDPE, and the PE matrix resin in the PE grafted acrylic acid is HDPE. The composite microspheres are hollow porous microspheres made of carboxyl-terminated hyperbranched polyester as the core and polyvinyl alcohol as the shell.

2. The high-permeability sanitary product comprising eccentric fibers according to claim 1, 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.

3. The high permeability sanitary product comprising eccentric fibers according to claim 2, characterized in that: The cross-linking agent is carbodiimide and N-hydroxysuccinimide in a mass ratio of 1:(0.8-1).

4. 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.

5. A method for preparing a high-permeability sanitary product comprising eccentric fibers according to any one of claims 1 to 4, 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, carboxyl-terminated 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.

6. The method for preparing a high-permeability sanitary product comprising eccentric fibers according to claim 5, characterized in that: The graphene oxide is pretreated as follows before being mixed with the PE resin and the 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 the graphene oxide to the 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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