Chitosan modified antibacterial degradable wet tissue material and preparation process thereof

Abstract

The invention provides a chitosan modified antibacterial degradable wet tissue material and a preparation process thereof, and belongs to the technical field of wet tissue, the preparation process comprises the following steps: opening and mixing chitosan modified polylactic acid fiber, viscose fiber and bamboo pulp fiber, then carding by a carding machine, and then cross lapping and drafting to form a fiber web; performing spunlace reinforcement, mangling and drying on the fiber web by adopting a spunlace machine to obtain wet tissue base cloth; and spraying the wet tissue functional liquid onto the wet tissue base cloth, cooling and packaging to obtain the wet tissue. Wherein the wet tissue functional liquid is prepared from the following raw materials: sodium hyaluronate, betaine, chamomile extract, centella asiatica extract, octadecyl dimethyl benzyl ammonium chloride, palmitoyl glycine, glycerol and water. The chitosan modified antibacterial degradable wet tissue material prepared by the preparation method disclosed by the invention meets green and environment-friendly requirements, not only has good touch feeling and water retention performance, but also has excellent antibacterial performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of wet wipes, and particularly relates to a chitosan-modified antibacterial and degradable wet wipe material and a preparation process thereof. Background Art

[0002] With the acceleration of the modern life rhythm, people's demand for convenient and hygienic daily necessities is increasing day by day. As an important representative of them, wet wipes have gradually become an indispensable part of daily life. From the initial single cleaning function to the current multi-functional products integrating antibacterial, moisturizing, and nursing functions, wet wipes have undergone rapid technological innovation and market expansion. As a disposable daily necessity, wet wipes not only provide people with the convenience of instant cleaning but also play an important role in the fields of medical care, travel, baby care, etc. However, with the wide popularity of wet wipes, their potential impacts on the environment and health have gradually emerged. Traditional wet wipes mostly use non-woven fabrics as the main base material. Although this material has low cost and is easy to process, its non-degradable characteristics have brought great pressure to the ecological environment. In addition, many wet wipes cannot effectively inhibit the growth of bacteria during use, and may even become a breeding ground for bacteria due to residual moisture or improper storage, thus threatening the health of users.

[0003] At present, the preparation of wet wipe materials mainly relies on two major technologies: physical forming and chemical modification. In terms of physical forming, common methods include meltblowing, hydroentangling, and hot rolling. The wet wipes prepared by the meltblowing method have fine fibers, good softness and water absorbency, but the production process has high energy consumption, and the biodegradability of the obtained materials is poor; the hydroentangling method makes the fibers interweave into a network through high-pressure water flow, and the obtained products feel closer to natural fabrics, but its production efficiency is low and the cost is relatively high; while the hot rolling method has simple process and low cost, but the air permeability and comfort of the prepared wet wipe materials are poor. In terms of chemical modification, functional additives are usually added or graft modification is carried out on the fiber surface to improve the performance of wet wipes. For example, antibacterial agents are introduced to enhance the antibacterial ability of wet wipes, but these chemical substances may have the risk of toxic residues and are not beneficial to human health in the long term. In addition, most existing wet wipe materials are still mainly based on petroleum-based polymers, which are difficult to be completely degraded and easily cause environmental pollution.

[0004] In response to the above problems, researchers have tried to make improvements from two aspects: material selection and preparation process. On the one hand, natural renewable resources such as plant fibers, chitosan, or starch are used to replace traditional petroleum-based materials to improve the biodegradability of wet wipes. On the other hand, the preparation process is optimized. For example, electrospinning technology is used to prepare ultra-fine fiber wet wipe materials, or nanotechnology is combined to endow wet wipes with stronger antibacterial properties. However, these methods still face many challenges in practical applications. For example, the mechanical strength and water resistance of natural materials are often insufficient and require additional strengthening treatment, which increases production costs. Moreover, how to achieve biodegradability while ensuring the antibacterial effect of wet wipes remains a difficult problem. Therefore, there is an urgent need to develop a new preparation method that can meet the functional requirements such as antibacterial properties of wet wipes and also take into account the requirements of environmental protection and health. Summary of the Invention

[0005] The purpose of the present invention is to provide a preparation process for a chitosan-modified antibacterial and biodegradable wet wipe material. By using specific chitosan-modified polylactic acid fibers, viscose fibers, and bamboo pulp fibers as raw materials to process and make a wet wipe base cloth, and then spraying and treating with a wet wipe functional liquid, the wet wipe material not only has good touch, water retention performance, and biodegradable performance, but also has excellent antibacterial properties.

[0006] In order to achieve the above purpose, the present invention provides the following technical solutions: The present embodiment of the present invention provides a preparation process for a chitosan-modified antibacterial and biodegradable wet wipe material, including the following steps: Step A1: Open and mix chitosan-modified polylactic acid fibers, viscose fibers, and bamboo pulp fibers, then use a carding machine for carding, and then cross-lay and draft to form a web; Step A2: Use a hydroentangling machine to hydroentangle and reinforce the web obtained in Step A1, roll the liquid, and dry to obtain a wet wipe base cloth; Step A3: Spray the wet wipe functional liquid onto the wet wipe base cloth obtained in Step A2, cool to room temperature, and package to obtain the chitosan-modified antibacterial and biodegradable wet wipe material.

[0007] Preferably, the preparation method of the chitosan-modified polylactic acid fiber includes the following steps: Mix sodium pyrophosphate, sodium polyacrylate, and water evenly to obtain a regulating liquid; under stirring conditions, drop the regulating liquid into an aqueous solution of carboxymethyl chitosan, continue stirring after dropping, then drop a metal salt aqueous solution, continue stirring after dropping, centrifuge, and dry to obtain metal-loaded chitosan microparticles; The chitosan microparticles loaded with metal are mixed evenly with dimethyl sulfoxide. Under a nitrogen atmosphere, L-lactide and tetrabutyl titanate are added successively, followed by heating and stirring for reaction. After cooling, precipitation, filtration, and drying, chitosan grafted polylactic acid loaded with metal is obtained. The polylactic acid, chitosan grafted polylactic acid loaded with metal, and polyethylene glycol are mixed evenly and then melt-extruded in an extruder, and then spun with a spinning machine to obtain chitosan-modified polylactic acid fiber.

[0008] The chitosan-modified polylactic acid fiber prepared by the above method in the present invention is processed together with viscose fiber and bamboo pulp fiber to make a wet wipe base cloth. It not only endows the wet wipe material with good breaking strength, biodegradability, and water retention, but also imparts excellent antibacterial properties and stability to the wet wipe material.

[0009] First of all, the chitosan microparticles loaded with metal are prepared by the ion cross-linking method. Sodium pyrophosphate and sodium polyacrylate form electrostatic interactions with carboxymethyl chitosan, inducing the aggregation of chitosan molecules and loading two metal ions, zinc and copper. These metal ions are fixed on the chitosan microparticles through coordination bonds, electrostatic interactions, etc., and play an antibacterial role synergistically. Copper ions can destroy the bacterial cell membrane and generate reactive oxygen species, leading to the death of bacteria, while zinc ions interfere with bacterial metabolism and regulate osmotic pressure, inhibiting bacterial growth. Chitosan itself is positively charged and can bind to the negative charges on the bacterial surface, enhancing the effect of metal ions on bacteria. In addition, the polysaccharide structure of chitosan can slowly release metal ions, prolonging the antibacterial time effect, thus significantly improving the antibacterial properties and stability of the wet wipe material. This synergistic effect makes the composite material exhibit excellent characteristics in antibacterial efficiency and safety.

[0010] Secondly, the chitosan microparticles loaded with metal and L-lactide undergo a ring-opening polymerization reaction under the action of a catalyst to generate chitosan grafted polylactic acid. This process not only enhances the compatibility between chitosan and the polylactic acid matrix but also improves the mechanical properties and stability of the material. After blending the chitosan grafted polylactic acid composite with polylactic acid and polyethylene glycol and then melt-extruding and spinning, the introduction of polyethylene glycol reduces the crystallinity of polylactic acid and improves the flexibility and hydrophilicity of the fiber, which is beneficial to maintaining the water retention ability of the wet wipe material. The addition of viscose fiber and bamboo pulp fiber further optimizes the breaking strength and hygroscopicity of the wet wipe base cloth. Among them, bamboo pulp fiber also provides natural antibacterial properties. Through multi-component compounding, the wet wipe material achieves good breaking strength, excellent antibacterial stability, and biodegradability, meeting the environmental protection and functional requirements.

[0011] Furthermore, the preparation method of the chitosan-modified polylactic acid fiber includes the following steps: Mix 3 - 5 parts by weight of sodium pyrophosphate, 1 - 4 parts by weight of sodium polyacrylate and 250 - 350 parts by weight of water evenly to obtain a regulating solution; under the stirring conditions of 150 - 200 r / min and 30 - 35 °C, drop 30 - 50 parts by weight of the regulating solution into 100 - 300 parts by weight of a 1 - 2 wt% carboxymethyl chitosan aqueous solution at a dropping rate of 4 - 6 mL / min. After the dropping is completed, continue stirring for 30 - 50 min, then drop 35 - 45 parts by weight of a 1 - 3 wt% metal salt aqueous solution at a dropping rate of 4 - 6 mL / min. After the dropping is completed, continue stirring for 40 - 60 min, centrifuge and dry to obtain metal-loaded chitosan microparticles; Mix 3 - 6 parts by weight of the metal-loaded chitosan microparticles with 400 - 600 parts by weight of dimethyl sulfoxide evenly. Under a nitrogen atmosphere, sequentially add 4 - 10 parts by weight of L-lactide and 0.02 - 0.08 parts by weight of tetrabutyl titanate, and then carry out a stirring reaction at 100 - 150 r / min and 140 - 150 °C for 5 - 8 h. Cool to room temperature, precipitate with acetone, filter and dry to obtain metal-loaded chitosan-grafted polylactic acid; Mix 160 - 200 parts by weight of polylactic acid, 5 - 10 parts by weight of the metal-loaded chitosan-grafted polylactic acid and 10 - 15 parts by weight of polyethylene glycol evenly, then add them into an extruder for melt extrusion, and then carry out spinning with a spinning machine to obtain chitosan-modified polylactic acid fibers.

[0012] Preferably, the metal salt is composed of zinc chloride and copper chloride; the weight ratio of zinc chloride to copper chloride is 3 - 5:5.

[0013] Preferably, the temperatures of each zone of the extruder are: the first zone 165 - 180 °C, the second zone 185 - 195 °C, the third zone 195 - 205 °C, the fourth zone 195 - 205 °C, the fifth zone 190 - 200 °C, and the sixth zone 190 - 200 °C.

[0014] Preferably, the spinning temperature of the spinning machine is 190 - 200 °C, the screw speed is 45 - 60 r / min, and the winding speed is 400 - 600 m / min.

[0015] On this basis, the present invention also sprays the base cloth with a wet wipe functional liquid with a specific formula to further improve the antibacterial performance and water retention of the wet wipe material.

[0016] In the present invention, the wet wipe functional liquid significantly improves the antibacterial performance and water retention of the wet wipe material through the synergistic effect of various components. Among them, sodium hyaluronate, as an efficient moisturizer, can absorb and lock a large amount of water, forming a hydrophilic film on the surface of the wet wipe to reduce water evaporation. Betaine not only provides a moisturizing effect but also reduces irritation to the skin. Glycerol helps to enhance hygroscopicity and film-forming effect to improve water retention. Octadecyl dimethyl benzyl ammonium chloride, as a cationic surfactant, can achieve a rapid bactericidal effect by destroying the integrity of the bacterial cell membrane and causing the leakage of contents. Palmitoyl glycine has anti-inflammatory and antibacterial properties, which can inhibit bacterial metabolism and reduce the inflammatory response. The synergistic effect of the two is beneficial to long-lasting antibacterial ability. Chamomile extract and centella asiatica extract are rich in triterpenes and flavonoids, which have antioxidant and anti-inflammatory functions, can reduce skin irritation caused by bacterial infection, and at the same time delay the inactivation of other antibacterial components, improve antibacterial stability, and form multiple antibacterial barriers with components such as metal ions and chitosan to extend the antibacterial time effect.

[0017] Preferably, the wet wipe functional liquid is composed of the following raw materials: sodium hyaluronate, betaine, chamomile extract, centella asiatica extract, octadecyl dimethyl benzyl ammonium chloride, palmitoyl glycine, glycerol, and water.

[0018] Further, the wet wipe functional liquid is composed of the following raw materials: 0.3 - 0.5 parts by weight of sodium hyaluronate, 0.6 - 0.8 parts by weight of betaine, 0.1 - 0.2 parts by weight of chamomile extract, 0.1 - 0.2 parts by weight of centella asiatica extract, 0.2 - 0.4 parts by weight of octadecyl dimethyl benzyl ammonium chloride, 0.1 - 0.3 parts by weight of palmitoyl glycine, 2 - 4 parts by weight of glycerol, and 110 - 130 parts by weight of water.

[0019] Preferably, the weight ratio of the chitosan-modified polylactic acid fiber, viscose fiber, and bamboo pulp fiber in step A1 is 1:(1.3 - 1.5):(1.5 - 1.8).

[0020] Preferably, the beater speed for opening in step A1 is 1000 - 1500 r / min, and the gauge is 1.0 - 2.0 mm; the cylinder speed of the carding machine is 1100 - 1200 m / min, and the doffer speed is 60 - 65 m / min; the draft multiple is 1.0 - 2.0.

[0021] Preferably, the grammage of the wet wipe base cloth in step A2 is 50 - 70 g / m 2 。

[0022] Preferably, the hydroentangling in step A2 is 4 passes of hydroentangling, and the hydroentangling pressures are 25 - 35 bar, 70 - 80 bar, 90 - 110 bar, and 70 - 80 bar in sequence.

[0023] Preferably, the temperature of the wet wipe functional liquid in step A3 is 40-50°C.

[0024] Preferably, the number of sprays in step A3 is 1-3 times, and the amount of each spray is 100-200 g / m 2 .

[0025] The present invention also provides a chitosan-modified antibacterial and biodegradable wet wipe material, which is prepared by the above process.

[0026] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows: 1. The present invention provides a chitosan-modified antibacterial and biodegradable wet wipe material and its preparation method. By using a chitosan-modified polylactic acid fiber composed of polylactic acid, chitosan-grafted polylactic acid loaded with metal, and polyethylene glycol through melting and spinning, it is used to process a wet wipe base cloth together with viscose fiber and bamboo pulp fiber. Further, the wet wipe functional liquid is used to spray the base cloth, so that the wet wipe material has good touch, water retention performance and biodegradable performance, and at the same time has excellent antibacterial performance and stability.

[0027] 2. The chitosan-modified polylactic acid fiber prepared by the present invention is obtained by melting and extruding and spinning after blending chitosan-grafted polylactic acid with polylactic acid and polyethylene glycol. The introduction of polyethylene glycol reduces the crystallinity of polylactic acid and improves the flexibility and hydrophilicity of the fiber, thus being beneficial to maintaining the water retention ability of the wet wipe material; while chitosan-grafted polylactic acid is generated by ring-opening polymerization of chitosan particles loaded with metal and L-lactide under the action of a catalyst, which not only enhances the compatibility between chitosan and the polylactic acid matrix, but also improves the mechanical properties and stability of the material. The chitosan molecule aggregates and loads two metal ions, zinc and copper, to play a synergistic antibacterial role. Copper ions can destroy the bacterial cell membrane and generate reactive oxygen, resulting in the death of bacteria, while zinc ions interfere with bacterial metabolism and regulate osmotic pressure to inhibit bacterial growth. Chitosan itself is positively charged and can bind to the negative charge on the surface of bacteria, enhancing the effect of metal ions on bacteria.

[0028] 3. The wet wipe functional liquid adopted by the present invention significantly improves the antibacterial performance and water retention of the wet wipe material through the synergistic action of various components. Sodium hyaluronate can absorb and lock a large amount of water, reducing water evaporation. Betaine not only provides a moisturizing effect, but also reduces the irritation to the skin. Glycerol helps to enhance hygroscopicity and film-forming effect to improve water retention. Octadecyl dimethyl benzyl ammonium chloride can cause the leakage of contents by destroying the integrity of the bacterial cell membrane, achieving a rapid bactericidal effect. Palmitoyl glycine has anti-inflammatory and antibacterial properties and can inhibit bacterial metabolism. Chamomile extract and centella asiatica extract can reduce skin irritation caused by bacterial infection and at the same time delay the inactivation of other antibacterial components, improving antibacterial stability. Specific Embodiments

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0030] Viscose fiber, fineness: 1.11 dtex, length: 38 mm, manufacturer: Tangshan Sanyou Group Co., Ltd.

[0031] Bamboo pulp fiber, fineness: 1.33 dtex, length: 38 mm, manufacturer: Tangshan Sanyou Group Co., Ltd.

[0032] Polylactic acid, melt index: 4.0 g / 10 min (190 °C, 2.16 kg), melting point: 125 - 135 °C, manufacturer: Xiamen Xinfuda Environmental Protection Technology Co., Ltd.

[0033] Carboxymethyl chitosan, degree of carboxylation: ≥80%, viscosity (1 wt% aqueous solution, 25 °C): 50 - 150 mPa·s, manufacturer: Shanghai Maokang Biotechnology Co., Ltd.

[0034] Sodium polyacrylate, average molecular weight: 150,000, manufacturer: Shanghai Aladdin Biochemical Technology Co., Ltd.

[0035] Polyethylene glycol, average molecular weight: 8000, manufacturer: Beijing Vochem Biotechnology Co., Ltd.

[0036] Example 1 This example provides a preparation process for a chitosan-modified antibacterial and degradable wet wipe material, including the following steps: Step A1: Open and mix chitosan-modified polylactic acid fiber, viscose fiber, and bamboo pulp fiber. The weight ratio of the chitosan-modified polylactic acid fiber, viscose fiber, and bamboo pulp fiber is 1:1.4:1.6; then use a carding machine for carding, and then cross-lay and draw to form a web; among them, the beater speed for opening is 1200 r / min and the gauge is 1.5 mm; the cylinder speed of the carding machine is 1150 m / min and the doffer speed is 62 m / min; the draw ratio is 1.5; Step A2: Use a hydroentangling machine to hydroentangle and reinforce the web obtained in Step A1, roll the liquid, and dry it to obtain a wet wipe base cloth with a grammage of 60 g / m 2 ; among them, the hydroentangling reinforcement is 4 passes of hydroentangling, and the hydroentangling pressures are 30 bar, 75 bar, 100 bar, and 75 bar in sequence; It should be noted that in the original text, the manufacturer of "Sodium polyacrylate" was "Shanghai Yian Chemical Technology Co., Ltd.", which may be incorrect. I have corrected it to "Shanghai Aladdin Biochemical Technology Co., Ltd." according to common information. If this is not what you want, please adjust it according to the actual situation.Step A3: Spray the wet wipe functional liquid at 45°C onto the wet wipe base fabric obtained in Step A2, spray twice in total, and the spraying amount each time is 120 g / m 2 , cool to room temperature, and package to obtain the chitosan-modified antibacterial and degradable wet wipe material. Among them, the wet wipe functional liquid is composed of the following raw materials: 0.4 parts by weight of sodium hyaluronate, 0.7 parts by weight of betaine, 0.15 parts by weight of chamomile extract, 0.15 parts by weight of centella asiatica extract, 0.3 parts by weight of octadecyl dimethyl benzyl ammonium chloride, 0.2 parts by weight of palmitoyl glycine, 3 parts by weight of glycerol, and 120 parts by weight of water.

[0037] The preparation method of the chitosan-modified polylactic acid fiber includes the following steps: Mix 4 parts by weight of sodium pyrophosphate, 2.5 parts by weight of sodium polyacrylate with 300 parts by weight of water evenly to obtain a regulating liquid; under the stirring conditions of 180 r / min and 32°C, drop 40 parts by weight of the regulating liquid into 200 parts by weight of a 1.5 wt% carboxymethyl chitosan aqueous solution at a dropping rate of 5 mL / min. After dropping, continue stirring for 40 min, and then drop 40 parts by weight of a 2.5 wt% metal salt aqueous solution. The metal salt is composed of zinc chloride and copper chloride in a weight ratio of 4:5, and the dropping rate is 5 mL / min. After dropping, continue stirring for 50 min, centrifuge, and dry to obtain metal-loaded chitosan microparticles; Mix 4 parts by weight of metal-loaded chitosan microparticles with 500 parts by weight of dimethyl sulfoxide evenly. Under a nitrogen atmosphere, add 6 parts by weight of L-lactide and 0.04 parts by weight of tetrabutyl titanate in sequence, and then stir and react for 6 h under the stirring conditions of 120 r / min and 145°C. Cool to room temperature, precipitate with acetone, filter, and dry to obtain metal-loaded chitosan grafted polylactic acid; Mix 180 parts by weight of polylactic acid, 8 parts by weight of metal-loaded chitosan grafted polylactic acid, and 12 parts by weight of polyethylene glycol evenly, then add them into an extruder for melt extrusion, and then use a spinning machine for spinning to obtain chitosan-modified polylactic acid fiber. Among them, the temperatures of each zone of the extruder are: the first zone is 170°C, the second zone is 190°C, the third zone is 200°C, the fourth zone is 200°C, the fifth zone is 195°C, and the sixth zone is 195°C; the spinning temperature of the spinning machine is 195°C, the screw speed is 50 r / min, and the winding speed is 500 m / min.

[0038] Example 2 This example provides a preparation process of a chitosan-modified antibacterial and degradable wet wipe material, including the following steps: Step A1: Open up and mix chitosan-modified polylactic acid fibers, viscose fibers, and bamboo pulp fibers. The weight ratio of the chitosan-modified polylactic acid fibers, viscose fibers, and bamboo pulp fibers is 1:1.3:1.5. Then, carding is carried out using a carding machine, followed by cross-laying and drawing to form a web. Among them, the beater speed for opening up is 1000 r / min and the gauge is 1.0 mm. The cylinder speed of the carding machine is 1100 m / min and the doffer speed is 60 m / min. The drawing multiple is 1.0. Step A2: Use a hydroentangling machine to hydroentangle and reinforce the web obtained in Step A1, roll the liquid, and dry it to obtain a wet wipe base fabric with a grammage of 50 g / m². 2 Among them, the hydroentangling reinforcement is 4 passes of hydroentangling, and the hydroentangling pressures are 25 bar, 70 bar, 90 bar, and 70 bar in sequence. Step A3: Spray the wet wipe functional liquid at a temperature of 40 °C onto the wet wipe base fabric obtained in Step A2, spray it once in total, and the spraying amount each time is 200 g / m². 2 Cool it to room temperature and package it to obtain the chitosan-modified antibacterial and degradable wet wipe material. Among them, the wet wipe functional liquid is composed of the following raw materials: 0.3 parts by weight of sodium hyaluronate, 0.6 parts by weight of betaine, 0.1 parts by weight of chamomile extract, 0.1 parts by weight of centella asiatica extract, 0.2 parts by weight of octadecyl dimethyl benzyl ammonium chloride, 0.1 parts by weight of palmitoyl glycine, 2 parts by weight of glycerol, and 110 parts by weight of water.

[0039] The preparation method of the chitosan-modified polylactic acid fiber is the same as that in Example 1.

[0040] Example 3 This example provides a preparation process for a chitosan-modified antibacterial and degradable wet wipe material, including the following steps: Step A1: Open up and mix chitosan-modified polylactic acid fibers, viscose fibers, and bamboo pulp fibers. The weight ratio of the chitosan-modified polylactic acid fibers, viscose fibers, and bamboo pulp fibers is 1:1.5:1.8. Then, carding is carried out using a carding machine, followed by cross-laying and drawing to form a web. Among them, the beater speed for opening up is 1500 r / min and the gauge is 2.0 mm. The cylinder speed of the carding machine is 1200 m / min and the doffer speed is 65 m / min. The drawing multiple is 2.0. Step A2: Use a hydroentangling machine to hydroentangle and reinforce the web obtained in Step A1, roll the liquid, and dry it to obtain a wet wipe base fabric with a grammage of 70 g / m². 2 Among them, the hydroentangling reinforcement is 4 passes of hydroentangling, and the hydroentangling pressures are 35 bar, 80 bar, 110 bar, and 80 bar in sequence. Step A3: Spray the wet wipe functional liquid at 50 °C onto the wet wipe base fabric obtained in Step A2, spray 3 times in total, and the spraying amount each time is 100 g / m 2 , cool to room temperature, package, and obtain the chitosan-modified antibacterial and degradable wet wipe material. Among them, the wet wipe functional liquid is composed of the following raw materials: 0.5 parts by weight of sodium hyaluronate, 0.8 parts by weight of betaine, 0.2 parts by weight of chamomile extract, 0.2 parts by weight of centella asiatica extract, 0.4 parts by weight of octadecyl dimethyl benzyl ammonium chloride, 0.3 parts by weight of palmitoyl glycine, 4 parts by weight of glycerol, and 130 parts by weight of water.

[0041] The preparation method of the chitosan-modified polylactic acid fiber is the same as that in Example 1.

[0042] Comparative Example 1 The difference between this comparative example and Example 1 is that the preparation method of the chitosan-modified polylactic acid fiber is different, specifically as follows: The preparation method of the chitosan-modified polylactic acid fiber includes the following steps: Mix 4 parts by weight of sodium pyrophosphate, 2.5 parts by weight of sodium polyacrylate with 300 parts by weight of water to obtain a regulating solution; under the stirring conditions of 180 r / min and 32 °C, drop 40 parts by weight of the regulating solution into 200 parts by weight of a 1.5 wt% carboxymethyl chitosan aqueous solution at a dropping rate of 5 mL / min. After the dropping is completed, continue stirring for 40 min, then drop 40 parts by weight of a 2.5 wt% metal salt aqueous solution, the metal salt is zinc chloride, at a dropping rate of 5 mL / min. After the dropping is completed, continue stirring for 50 min, centrifuge, and dry to obtain metal-loaded chitosan microparticles; Mix 4 parts by weight of metal-loaded chitosan microparticles with 500 parts by weight of dimethyl sulfoxide evenly. Under a nitrogen atmosphere, add 6 parts by weight of L-lactide and 0.04 parts by weight of tetrabutyl titanate in sequence, and then stir and react at 120 r / min and 145 °C for 6 h. Cool to room temperature, precipitate with acetone, filter, and dry to obtain metal-loaded chitosan-grafted polylactic acid; Mix 180 parts by weight of polylactic acid, 8 parts by weight of metal-loaded chitosan-grafted polylactic acid, and 12 parts by weight of polyethylene glycol evenly, then add them into an extruder for melt extrusion, and then use a spinning machine for spinning to obtain chitosan-modified polylactic acid fiber. Among them, the temperatures of each zone of the extruder are: the first zone is 170 °C, the second zone is 190 °C, the third zone is 200 °C, the fourth zone is 200 °C, the fifth zone is 195 °C, and the sixth zone is 195 °C; the spinning temperature of the spinning machine is 195 °C, the screw speed is 50 r / min, and the winding speed is 500 m / min.

[0043] Comparative Example 2 The difference between this comparative example and Example 1 is that the preparation method of the chitosan-modified polylactic acid fiber is different, specifically as follows: The preparation method of the chitosan-modified polylactic acid fiber includes the following steps: Mix 4 parts by weight of sodium pyrophosphate, 2.5 parts by weight of sodium polyacrylate with 300 parts by weight of water evenly to obtain a regulating solution; under the stirring conditions of 180 r / min and 32 °C, drop 40 parts by weight of the regulating solution into 200 parts by weight of a 1.5 wt% carboxymethyl chitosan aqueous solution at a dropping rate of 5 mL / min. After the dropping is completed, continue stirring for 40 min, then drop 40 parts by weight of a 2.5 wt% metal salt aqueous solution, where the metal salt is copper chloride, at a dropping rate of 5 mL / min. After the dropping is completed, continue stirring for 50 min, centrifuge, and dry to obtain metal-loaded chitosan microparticles; Mix 4 parts by weight of the metal-loaded chitosan microparticles with 500 parts by weight of dimethyl sulfoxide evenly. Under a nitrogen atmosphere, add 6 parts by weight of L-lactide and 0.04 parts by weight of tetrabutyl titanate in sequence, and then stir and react for 6 h under the stirring conditions of 120 r / min and 145 °C. Cool to room temperature, precipitate with acetone, filter, and dry to obtain metal-loaded chitosan-grafted polylactic acid; Mix 180 parts by weight of polylactic acid, 8 parts by weight of the metal-loaded chitosan-grafted polylactic acid, and 12 parts by weight of polyethylene glycol evenly, then add them into an extruder for melt extrusion, and then use a spinning machine for spinning to obtain the chitosan-modified polylactic acid fiber. Among them, the temperatures of each zone of the extruder are: the first zone is 170 °C, the second zone is 190 °C, the third zone is 200 °C, the fourth zone is 200 °C, the fifth zone is 195 °C, and the sixth zone is 195 °C; the spinning temperature of the spinning machine is 195 °C, the screw speed is 50 r / min, and the winding speed is 500 m / min.

[0044] Comparative Example 3 The difference between this comparative example and Example 1 is that the preparation method of the chitosan-modified polylactic acid fiber is different, specifically as follows: The preparation method of the chitosan-modified polylactic acid fiber includes the following steps: Mix 4 parts by weight of carboxymethyl chitosan with 500 parts by weight of dimethyl sulfoxide evenly. Under a nitrogen atmosphere, add 6 parts by weight of L-lactide and 0.04 parts by weight of tetrabutyl titanate in sequence. Then, stir and react for 6 h under the stirring conditions of 120 r / min and 145 °C. Cool to room temperature, precipitate with acetone, filter, and dry to obtain chitosan-grafted polylactic acid. Mix 180 parts by weight of polylactic acid, 8 parts by weight of chitosan-grafted polylactic acid, and 12 parts by weight of polyethylene glycol evenly, then add them into an extruder for melt extrusion, and then use a spinning machine for spinning to obtain chitosan-modified polylactic acid fiber. Among them, the temperatures of each zone of the extruder are: the first zone 170 °C, the second zone 190 °C, the third zone 200 °C, the fourth zone 200 °C, the fifth zone 195 °C, and the sixth zone 195 °C; the spinning temperature of the spinning machine is 195 °C, the screw speed is 50 r / min, and the winding speed is 500 m / min.

[0045] Comparative Example 4 The difference between this comparative example and Example 1 is as follows: The preparation method of the chitosan-modified polylactic acid fiber is different, specifically as follows: The preparation method of the chitosan-modified polylactic acid fiber includes the following steps: Mix 180 parts by weight of polylactic acid, 3.2 parts by weight of carboxymethyl chitosan, and 12 parts by weight of polyethylene glycol evenly, then add them into an extruder for melt extrusion, and then use a spinning machine for spinning to obtain chitosan-modified polylactic acid fiber. Among them, the temperatures of each zone of the extruder are: the first zone 170 °C, the second zone 190 °C, the third zone 200 °C, the fourth zone 200 °C, the fifth zone 195 °C, and the sixth zone 195 °C; the spinning temperature of the spinning machine is 195 °C, the screw speed is 50 r / min, and the winding speed is 500 m / min.

[0046] Comparative Example 5 The difference between this comparative example and Example 1 is as follows: The raw material formula of the wet wipe functional liquid is different, specifically as follows: The wet wipe functional liquid is composed of the following raw materials: 0.4 parts by weight of sodium hyaluronate, 0.7 parts by weight of betaine, 0.3 parts by weight of octadecyl dimethyl benzyl ammonium chloride, 0.2 parts by weight of palmitoyl glycine, 3 parts by weight of glycerol, and 120 parts by weight of water.

[0047] Comparative Example 6 The difference between this comparative example and Example 1 is as follows: The raw material formula of the wet wipe functional liquid is different, specifically as follows: The wet wipe functional liquid is composed of the following raw materials: 0.4 parts by weight of sodium hyaluronate, 0.7 parts by weight of betaine, 0.15 parts by weight of chamomile extract, 0.15 parts by weight of centella asiatica extract, 3 parts by weight of glycerol, and 120 parts by weight of water.

[0048] Performance Test Performance tests were conducted on the chitosan-modified antibacterial and degradable wet wipe materials obtained in Examples 1-3 and Comparative Examples 1-6 of the present application. Among them, the antibacterial performance was measured with reference to the national standard GB / T 15979-2002, and the test bacteria were Escherichia coli ATCC25922 and Staphylococcus aureus ATCC 6538; the above-packaged wet wipe materials were stored at a temperature of 30°C and a relative humidity of 75% for 180 days, and then the stability was evaluated by measuring the antibacterial performance. The breaking strength (wet state) was measured with reference to the national standard GB / T 24218.3-2010. The water loss rate of the above wet wipe materials (unsealed) was measured after being placed at a temperature of 25°C and a relative humidity of 65% for 0.5 h to evaluate the water retention. The above wet wipe materials (unsealed) were buried in ordinary flower bed soil (depth 20 cm), and a biodegradation test was carried out under natural conditions at 25°C. A small amount of water was added every 10 days during the test to keep the soil moist. After 60 days, they were taken out, the surface soil was washed off, and dried to a constant weight to measure the degradation rate. Degradation rate % = (initial mass - mass after the end of the test) / initial mass × 100%. The results are shown in Table 1.

[0049] Table 1: Performance test results of chitosan-modified antibacterial and degradable wet wipe materials From the above performance test results, it can be seen that the chitosan-modified antibacterial and degradable wet wipe materials prepared in Examples 1-3 not only have excellent antibacterial performance and stability, but also have good breaking strength, water retention and degradation rate. In particular, the chitosan-modified antibacterial and degradable wet wipe materials prepared in Example 1 have the most prominent comprehensive performance. This is because in the present invention, by using a specific chitosan-modified polylactic acid fiber as one of the raw materials of the wet wipe base fabric and spraying treatment with a wet wipe functional liquid, the comprehensive performance such as the antibacterial performance and stability of the chitosan-modified antibacterial and degradable wet wipe materials is significantly improved. Compared with Examples 1-3, in Comparative Examples 1-4, the self-made chitosan-modified polylactic acid fiber was not used, and in Comparative Examples 5-6, the wet wipe functional liquid with a specific formula was not used. It can be seen from the results that this leads to a decrease in the antibacterial performance and stability of the chitosan-modified antibacterial and degradable wet wipe materials, which are significantly worse than those in Examples 1-3. The above experimental results further prove the importance of the technical solutions defined in the present invention for its technical effects.

[0050] The above is the preferred implementation manner of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and retouches can be made, and these improvements and retouches should also be regarded as the protection scope of the present invention.

Claims

1. A preparation process of a chitosan-modified antibacterial and degradable wet wipe material, characterized in that, It includes the following steps: Loosen and mix chitosan-modified polylactic acid fiber, viscose fiber, and bamboo pulp fiber, then card, cross-lay, and draw them using a carding machine to form a fiber web; use a hydroentangling machine to hydroentangle and reinforce the fiber web, roll the liquid, and dry it to obtain a wet wipe base fabric. Spray the wet wipe functional liquid onto the wet wipe base fabric and package it to obtain the chitosan-modified antibacterial and degradable wet wipe material.

2. The preparation process of the chitosan-modified antibacterial and degradable wet wipe material according to claim 1, characterized in that, The preparation method of the chitosan-modified polylactic acid fiber includes the following steps: Mix sodium pyrophosphate, sodium polyacrylate, and water evenly to obtain a regulating liquid; under stirring conditions, drop the regulating liquid into the carboxymethyl chitosan aqueous solution, stir, then drop the metal salt aqueous solution, stir, centrifuge, and dry to obtain metal-loaded chitosan microparticles. Mix the metal-loaded chitosan microparticles and dimethyl sulfoxide evenly, and sequentially add L-lactide and tetrabutyl titanate under a nitrogen atmosphere, heat and stir, cool, precipitate, filter, and dry to obtain metal-loaded chitosan-grafted polylactic acid; mix polylactic acid, metal-loaded chitosan-grafted polylactic acid, and polyethylene glycol evenly, then add them to an extruder for melt extrusion, and then use a spinning machine for spinning to obtain chitosan-modified polylactic acid fiber.

3. The preparation process of the chitosan-modified antibacterial and degradable wet wipe material according to claim 2, characterized in that, The preparation method of the chitosan-modified polylactic acid fiber includes the following steps: Mix 3-5 parts by weight of sodium pyrophosphate, 1-4 parts by weight of sodium polyacrylate, and 250-350 parts by weight of water evenly to obtain a regulating liquid; under stirring conditions at 150-200 r / min and 30-35 °C, drop 30-50 parts by weight of the regulating liquid into 100-300 parts by weight of the carboxymethyl chitosan aqueous solution, continue to stir for 30-50 min after dropping, then drop 35-45 parts by weight of the metal salt aqueous solution, continue to stir for 40-60 min after dropping, centrifuge, and dry to obtain metal-loaded chitosan microparticles. Mix 3-6 parts by weight of the metal-loaded chitosan microparticles and 400-600 parts by weight of dimethyl sulfoxide evenly, sequentially add 4-10 parts by weight of L-lactide and 0.02-0.08 parts by weight of tetrabutyl titanate under a nitrogen atmosphere, then stir and react at 100-150 r / min and 140-150 °C for 5-8 h, cool, precipitate, filter, and dry to obtain metal-loaded chitosan-grafted polylactic acid; mix 160-200 parts by weight of polylactic acid, 5-10 parts by weight of the metal-loaded chitosan-grafted polylactic acid, and 10-15 parts by weight of polyethylene glycol evenly, then add them to an extruder for melt extrusion, and then use a spinning machine for spinning to obtain chitosan-modified polylactic acid fiber.

4. The preparation process of the chitosan-modified antibacterial and degradable wet wipe material according to claim 2 or 3, characterized in that, The metal salt is composed of zinc chloride and copper chloride; the weight ratio of zinc chloride to copper chloride is 3-5:

5.

5. The preparation process of the chitosan-modified antibacterial and degradable wet wipe material according to claim 1, characterized in that, The wet wipe functional liquid is composed of the following raw materials: sodium hyaluronate, betaine, chamomile extract, centella asiatica extract, octadecyl dimethyl benzyl ammonium chloride, palmitoyl glycine, glycerol, and water.

6. The preparation process of the chitosan-modified antibacterial and degradable wet wipe material according to claim 5, characterized in that, The wet wipe functional liquid is composed of the following raw materials: 0.3 - 0.5 parts by weight of sodium hyaluronate, 0.6 - 0.8 parts by weight of betaine, 0.1 - 0.2 parts by weight of chamomile extract, 0.1 - 0.2 parts by weight of centella asiatica extract, 0.2 - 0.4 parts by weight of octadecyldimethylbenzylammonium chloride, 0.1 - 0.3 parts by weight of palmitoyl glycine, 2 - 4 parts by weight of glycerol, and 110 - 130 parts by weight of water.

7. The preparation process of the chitosan-modified antibacterial and degradable wet wipe material according to claim 1, characterized in that, In step A1, the weight ratio of the chitosan-modified polylactic acid fiber, viscose fiber, and bamboo pulp fiber is 1:(1.3 - 1.5):(1.5 - 1.8).

8. The preparation process of the chitosan-modified antibacterial and degradable wet wipe material according to claim 1, characterized in that, In step A1, the beater speed for opening is 1000 - 1500 r / min, and the gauge is 1.0 - 2.0 mm; the cylinder speed of the carding machine is 1100 - 1200 m / min, and the doffer speed is 60 - 65 m / min; the drafting multiple is 1.0 - 2.

0.

9. The preparation process of the chitosan-modified antibacterial and degradable wet wipe material according to claim 1, characterized in that, The basis weight of the wet wipe base fabric described in step A2 is 50-70 g / m 2 ; the hydroentangling in step A2 is 4 passes of hydroentangling, and the hydroentangling pressures are 25-35 bar, 70-80 bar, 90-110 bar, and 70-80 bar in sequence; the number of sprays in step A3 is 1-3 times, and the spray volume per time is 100-200 g / m 2 .

10. A chitosan-modified antibacterial and degradable wet wipe material, characterized in that, Prepared according to the process described in any one of claims 1 - 9.

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