An environmentally friendly biodegradable wet wipe and its preparation method

Abstract

This invention discloses an environmentally friendly and biodegradable wet wipe and its preparation method, belonging to the field of wet wipe technology. It includes a wet wipe substrate and a wet wipe impregnation solution. The wet wipe substrate comprises the following raw materials in parts by weight: 67-83 parts modified polylactic acid fiber, 37-49 parts cotton fiber, and 26-38 parts wood pulp fiber. The wet wipe impregnation solution comprises the following raw materials in parts by weight: 80-100 parts deionized water, 2-4 parts glycerol, 1-3 parts propylene glycol, 0.5-1.5 parts hyaluronic acid, and 0.3-0.5 parts preservative. The wet wipe substrate imparts excellent biodegradability to the wet wipe; the addition of modified polyethylene glycol to the modified polylactic acid fiber significantly enhances the hydrophilicity of polylactic acid, and the presence of antibacterial groups in the molecule further synergistically improves the antibacterial properties of the wet wipe. In summary, the wet wipe prepared by this invention possesses both hydrophilicity and antibacterial properties, and is environmentally friendly and biodegradable, possessing significant application value in the field of wet wipe technology.

Description

Technical Field

[0001] This invention belongs to the field of wet wipes technology, specifically, it relates to an environmentally friendly biodegradable wet wipe and its preparation method. Background Technology

[0002] Wet wipes are typically made from pure water, spunlace nonwoven fabric, and propylene glycol, and are used for wiping the face, hands, or skin. Spunlace nonwoven fabric is a nonwoven material that uses high-pressure water jets to puncture and entangle the fiber web, reinforcing it into a fabric. Due to its characteristics, nonwoven fabric production offers advantages such as simple processes, high production efficiency, low cost, wide applications, and diverse sources, leading to its widespread use in clothing linings, medical dressings, industrial filter linings, and thermal insulation packaging, among many other fields.

[0003] Traditional nonwoven fabrics are made from synthetic fibers such as polyethylene, polypropylene, aramid, and polyester, as well as natural fibers such as cotton and linen. This makes them difficult to degrade in the natural environment, leading to frequent waste accumulation after disposal. Statistics show that approximately 70% of the wet wipes generated globally each year end up in landfills or natural water bodies. These non-degradable materials can remain in the soil for hundreds of years, not only consuming vast amounts of land resources but also carrying microplastic particles into marine ecosystems through rainwater runoff, threatening biodiversity.

[0004] With the development of microbial technology, several biodegradable plastics have emerged worldwide, among which polylactic acid (PLA) is gaining increasing popularity. PLA is a polyester polymer obtained by polymerizing lactic acid as the main raw material. Its raw material is starch derived from renewable plant resources, and after use, it can be completely degraded by microorganisms in nature, ultimately producing carbon dioxide and water. Its source and post-processing are extremely environmentally friendly, making it an ideal green polymer material. Therefore, various nonwoven fabrics made from PLA are biodegradable. However, PLA has a strong lipophilicity, which is not conducive to improving the absorbency and water retention of disinfectant wipes. Finally, although PLA fibers possess certain natural antibacterial properties, their antibacterial performance needs further enhancement for disinfectant wipes. In conclusion, there is an urgent need to invent an environmentally friendly biodegradable wipe that combines absorbency and antibacterial properties to meet the higher demands of the wipe technology field. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide an environmentally friendly biodegradable wet wipe and its preparation method.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] An environmentally friendly biodegradable wet wipe, comprising a wet wipe substrate and a wet wipe impregnation solution.

[0008] Furthermore, the wet wipe substrate comprises the following raw materials in parts by weight: 67-83 parts modified polylactic acid fiber, 37-49 parts cotton fiber, and 26-38 parts wood pulp fiber.

[0009] Furthermore, the wet wipe soaking solution comprises the following raw materials in parts by weight: 80-100 parts deionized water, 2-4 parts glycerol, 1-3 parts propylene glycol, 0.5-1.5 parts hyaluronic acid, and 0.3-0.5 parts preservative.

[0010] Furthermore, the preservative is one of parabens, phenoxyethanol, and potassium sorbate.

[0011] Furthermore, the modified polylactic acid fiber is prepared by the following steps:

[0012] Step 1: Dry and mix PLLA (polylactic acid), modified polyethylene glycol, talc, and antioxidant to form a mixture;

[0013] Step 2: Add the mixture to the melt spinning equipment, perform melt spinning, and collect the resulting nascent fibers;

[0014] Step 3: The nascent fibers are subjected to thermal stretching and thermal setting in sequence to obtain modified polylactic acid fibers.

[0015] Furthermore, the raw materials are as follows by weight: 62-76 parts PLLA polylactic acid, 12-18 parts modified polyethylene glycol, 1-3 parts talc, and 3-6 parts antioxidant.

[0016] Furthermore, the antioxidant is a hindered phenolic antioxidant.

[0017] Furthermore, the drying temperature is 80-120℃, and the time is 6-12 hours.

[0018] Furthermore, the spinning temperature of the melt spinning is 180-220℃, and the spinning speed is 300-400m / min.

[0019] Adding a small amount of talc to modified polylactic acid (PLA) fibers can enhance the mechanical properties of PLA; adding hindered phenolic antioxidants can also improve the antioxidant properties of PLA.

[0020] Furthermore, the modified polyethylene glycol is prepared through the following steps:

[0021] A1. Under a nitrogen atmosphere, pyridine, polyethylene glycol, and anhydrous toluene were added sequentially to a 500 mL three-necked flask containing a stir bar. After stirring until homogeneous, the apparatus was heated. When the temperature reached 70°C, thionyl chloride was slowly added dropwise to the flask. The reaction was carried out at a constant temperature for 5 hours. During the reaction, the solution changed from a colorless solution to a white emulsion. After the reaction was completed, the mixture was allowed to stand and separate into layers. The upper layer was directly filtered to remove pyridine chloride, and the upper filtrate was obtained. The lower oily substance was then washed with toluene. After washing, the mixture was mixed with the upper filtrate and distilled using a rotary evaporator to remove thionyl chloride and most of the toluene. After cooling and filtration, the remaining toluene was removed by distillation again to obtain chlorinated polyethylene glycol.

[0022] Under the catalysis of pyridine, excess thionyl chloride reacts with polyethylene glycol; the reaction equation is shown below:

[0023]

[0024] A2. 5,5-Dimethylhydantoin, deionized water and sodium hydroxide were added sequentially to a 500 mL three-necked flask containing a stir bar. After stirring continuously until the solute was completely dissolved, chlorinated polyethylene glycol was added. The apparatus was heated and the reaction was stirred at a constant temperature for 4 h when the temperature reached 50 °C. After the reaction was completed, the water in the solution was removed by vacuum distillation using a rotary evaporator. The obtained solid was dissolved in anhydrous ethanol and filtered to obtain the intermediate product.

[0025] Under the catalysis of sodium hydroxide, chlorinated polyethylene glycol undergoes a nucleophilic substitution reaction with 5,5-dimethylhydantoin. The molar ratio of the two substances is controlled at 2:1 (with a slight excess of 5,5-dimethylhydantoin). The reaction equation is shown below:

[0026]

[0027] A3. Add the intermediate product, tert-butanol and deionized water sequentially to a 500mL three-necked flask containing a stir bar. After stirring evenly, add sodium hypochlorite to the three-necked flask. Place the apparatus under light-protected conditions and stir at room temperature for 6 hours. After the reaction is complete, perform vacuum distillation using a rotary evaporator and vacuum dry to obtain modified polyethylene glycol.

[0028] Under the action of sodium hypochlorite, the NH bond in the intermediate product molecule is transformed into an N-Cl bond, yielding modified polyethylene glycol.

[0029] Furthermore, in step A1, the ratio of pyridine, polyethylene glycol, anhydrous toluene, and thionyl chloride is 2.1 g: 100 g: 200 mL: 29.7 g.

[0030] Furthermore, in step A2, the ratio of 5,5-dimethylhydantoin, deionized water, sodium hydroxide, and chlorinated polyethylene glycol is 26.7 g: 150 mL: 9.6 g: 102.1 g.

[0031] Furthermore, in step A3, the ratio of the intermediate product, tert-butanol, deionized water, and sodium hypochlorite is 121.7g:80mL:70mL:14.8g.

[0032] Polyethylene glycol (PEG) contains a large number of ether bonds, making it a high-molecular-weight compound with excellent hydrophilicity. Using PEG as a raw material to modify polylactic acid (PLA) can significantly improve PLA's hydrophilicity. Furthermore, this invention modifies PEG by introducing chloramine groups into its molecular chain, releasing active halogens that disrupt microbial cell membranes, inhibit enzyme activity, oxidize nucleic acids, and interfere with protein function, achieving a highly efficient bactericidal effect. It also exhibits a broad antibacterial spectrum, is relatively safe for humans, and greatly enhances the antibacterial properties of PLA. Finally, this invention selects PEG with a molecular weight of 1000, which has a relatively large molecular weight, making it less prone to migration within the PLA matrix and exhibiting more stable performance.

[0033] A method for preparing environmentally friendly biodegradable wet wipes includes the following steps:

[0034] Modified polylactic acid fiber, cotton fiber, and wood pulp fiber are laid in layers in the order of upper, middle, and lower layers to form a fiber web. The fiber web is then reinforced using a hydroentangling process to form a nonwoven fabric. The nonwoven fabric is dried, then wound into rolls using a winding device, cut, and then soaked in a wet wipe solution before being sealed and packaged to obtain environmentally friendly and biodegradable wet wipes.

[0035] The beneficial effects of this invention are:

[0036] 1. The wet wipe substrate obtained by the present invention is modified polylactic acid fiber, cotton fiber and wood pulp fiber, which endows the wet wipe with excellent biodegradability and is environmentally friendly;

[0037] 2. By adding antioxidants, talc, and modified polyethylene glycol, polylactic acid is modified. The modified polyethylene glycol can significantly enhance the hydrophilicity of polylactic acid and has antibacterial groups attached to its molecules. It can also work synergistically with polylactic acid to improve the antibacterial properties of the wipes.

[0038] In summary, the wet wipes produced by this invention have both hydrophilic and antibacterial properties, and are environmentally friendly and biodegradable, thus possessing significant application value in the field of wet wipe technology. Detailed Implementation

[0039] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0040] Example 1

[0041] Preparation of modified polyethylene glycol:

[0042] A1. Under a nitrogen atmosphere, 2.1 g pyridine, 100 g polyethylene glycol, and 200 mL anhydrous toluene were added sequentially to a 500 mL three-necked flask containing a stir bar. After stirring evenly, the apparatus was heated. When the temperature reached 70 °C, 29.7 g thionyl chloride was slowly added dropwise to the flask. The reaction was carried out at a constant temperature for 5 h. During the reaction, the solution changed from a colorless solution to a white emulsion. After the reaction was completed, the solution was allowed to stand and separate into layers. The upper layer solution was directly filtered to remove pyridine chloride, and the upper filtrate was obtained. The lower oily substance was then washed with toluene. After washing, the mixture was mixed with the upper filtrate and distilled using a rotary evaporator to remove thionyl chloride and most of the toluene. After cooling and filtration, the remaining toluene was removed by distillation again to obtain chlorinated polyethylene glycol.

[0043] A2. 26.7 g of 5,5-dimethylhydantoin, 150 mL of deionized water and 9.6 g of sodium hydroxide were added sequentially to a 500 mL three-necked flask containing a stir bar. After stirring continuously until the solute was completely dissolved, 102.1 g of chlorinated polyethylene glycol was added. The apparatus was heated, and when the temperature reached 50 °C, the reaction was stirred at a constant temperature for 4 h. After the reaction was completed, the water in the solution was removed by vacuum distillation using a rotary evaporator. The obtained solid was dissolved in anhydrous ethanol and filtered to obtain the intermediate product.

[0044] A3. Add 121.7g of intermediate product, 80mL of tert-butanol and 70mL of deionized water to a 500mL three-necked flask containing a stir bar in sequence. After stirring evenly, add 14.8g of sodium hypochlorite to the three-necked flask. Place the apparatus under light-proof conditions and stir at room temperature for 6 hours. After the reaction is complete, perform vacuum distillation using a rotary evaporator and vacuum drying to obtain modified polyethylene glycol.

[0045] Example 2

[0046] Preparation of modified polyethylene glycol:

[0047] A1. Under a nitrogen atmosphere, 4.1 g of pyridine, 200 g of polyethylene glycol, and 400 mL of anhydrous toluene were added sequentially to a 1000 mL three-necked flask containing a stir bar. After stirring evenly, the apparatus was heated. When the temperature reached 70 °C, 59.4 g of thionyl chloride was slowly added dropwise to the flask. The reaction was carried out at a constant temperature for 5 h. During the reaction, the solution changed from a colorless solution to a white emulsion. After the reaction was completed, the solution was allowed to stand and separate into layers. The upper layer solution was directly filtered to remove pyridine chloride, and the upper filtrate was obtained. The lower oily substance was then washed with toluene. After washing, the mixture was mixed with the upper filtrate and distilled using a rotary evaporator to remove thionyl chloride and most of the toluene. After cooling and filtration, the remaining toluene was removed by distillation again to obtain chlorinated polyethylene glycol.

[0048] A2. 53.4 g of 5,5-dimethylhydantoin, 300 mL of deionized water and 19.2 g of sodium hydroxide were added sequentially to a 1000 mL three-necked flask containing a stir bar. After stirring continuously until the solute was completely dissolved, 204.2 g of chlorinated polyethylene glycol was added. The apparatus was heated and the reaction was carried out at 50 °C for 4 h with constant temperature stirring. After the reaction was completed, the water in the solution was removed by vacuum distillation using a rotary evaporator. The obtained solid was dissolved in anhydrous ethanol and filtered to obtain the intermediate product.

[0049] A3. Add 243.4 g of intermediate product, 160 mL of tert-butanol and 140 mL of deionized water to a 1000 mL three-necked flask containing a stir bar. After stirring evenly, add 29.6 g of sodium hypochlorite to the three-necked flask. Place the apparatus under light-proof conditions and stir at room temperature for 6 hours. After the reaction is complete, perform vacuum distillation using a rotary evaporator and vacuum drying to obtain modified polyethylene glycol.

[0050] Example 3

[0051] Preparation of modified polylactic acid fibers:

[0052] Step 1: 62g of PLLA polylactic acid (molecular weight 1000), 12g of modified polyethylene glycol prepared in Example 1, 1g of talc powder and 3g of antioxidant 1010 are dried at 80°C for 6 hours and then mixed to form a mixture.

[0053] Step 2: Add the mixture to the melt spinning equipment, melt spin at a temperature of 180℃ and a spinning speed of 300m / min, and collect the resulting nascent fibers;

[0054] Step 3: The nascent fibers are subjected to thermal stretching and thermal setting in sequence to obtain modified polylactic acid fibers.

[0055] Example 4

[0056] Preparation of modified polylactic acid fibers:

[0057] Step 1: 76g of PLLA polylactic acid (molecular weight 1000), 18g of modified polyethylene glycol prepared in Example 2, 3g of talc powder and 6g of antioxidant 1010 are dried at 120°C for 12 hours and then mixed to form a mixture.

[0058] Step 2: Add the mixture to the melt spinning equipment, melt spin at a temperature of 220℃ and a spinning speed of 400m / min, and collect the resulting nascent fibers;

[0059] Step 3: The nascent fibers are subjected to thermal stretching and thermal setting in sequence to obtain modified polylactic acid fibers.

[0060] Example 5

[0061] 67g of modified polylactic acid fiber, 37g of cotton fiber, and 26g of wood pulp fiber prepared in Example 3 were laid out in layers in the order of upper, middle and lower layers to form a fiber web. The fiber web was then reinforced by a hydroentangling process to obtain a nonwoven fabric.

[0062] Example 6

[0063] 75g of modified polylactic acid fiber, 43g of cotton fiber, and 32g of wood pulp fiber prepared in Example 4 were laid out in layers in the order of upper, middle and lower layers to form a fiber web. The fiber web was then reinforced by a hydroentangling process to obtain a nonwoven fabric.

[0064] Example 7

[0065] 83g of modified polylactic acid fiber, 49g of cotton fiber, and 38g of wood pulp fiber prepared in Example 4 were laid out in layers in the order of upper, middle and lower layers to form a fiber web. The fiber web was then reinforced by a hydroentangling process to obtain a nonwoven fabric.

[0066] Example 8

[0067] 67g of modified polylactic acid fiber, 37g of cotton fiber, and 26g of wood pulp fiber prepared in Example 3 were laid out in layers in the order of upper, middle, and lower layers to form a fiber web. The fiber web was then reinforced using a hydroentangling process to obtain a nonwoven fabric. The nonwoven fabric was dried, then wound into a roll using a winding device, cut, and then soaked in a wet wipe solution before being sealed and packaged to obtain an environmentally friendly and biodegradable wet wipe.

[0068] The wet wipe soaking solution is prepared by uniformly mixing 80g deionized water, 2g glycerol, 1g propylene glycol, 0.5g hyaluronic acid, and 0.3g p-hydroxybenzoate.

[0069] Example 9

[0070] 83g of modified polylactic acid fiber, 49g of cotton fiber, and 38g of wood pulp fiber prepared in Example 4 were laid out in layers in the order of upper, middle, and lower layers to form a fiber web. The fiber web was then reinforced using a hydroentangling process to obtain a nonwoven fabric. The nonwoven fabric was dried, then wound into a roll using a winding device, cut, and then soaked in a wet wipe solution before being sealed and packaged to obtain an environmentally friendly and biodegradable wet wipe.

[0071] The wet wipe soaking solution is prepared by uniformly mixing 100g deionized water, 4g glycerol, 3g propylene glycol, 1.5g hyaluronic acid, and 0.5g potassium sorbate.

[0072] Comparative Example 1

[0073] In the preparation process of Example 7, only the modified polylactic acid fiber was replaced with an equal amount of ordinary polylactic acid fiber, while the other conditions remained unchanged, and a nonwoven fabric was obtained.

[0074] Comparative Example 2

[0075] Use commercially available polylactic acid nonwoven fabric.

[0076] The following performance tests were conducted on Examples 5, 6, and 7, and Comparative Examples 1 and 2:

[0077] The antibacterial rates of Streptococcus mutans and Staphylococcus aureus were determined according to the national standard GB / T 20944.3-2008.

[0078] The water absorption ratio was determined according to the national standard GB / T 24218-2017.

[0079] The compost degradation was determined using standard ISO 14855:1999.

[0080] The measurement results are shown in the table below:

[0081]

[0082] As can be seen from the table above, the nonwoven fabric prepared in the embodiments of the present invention has higher hydrophilicity and antibacterial properties than the comparative example, and is also biodegradable. Using it as a raw material for wet wipes can improve the hydrophilicity and antibacterial properties of wet wipes. Therefore, the present invention has important application value in the field of wet wipe technology.

[0083] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0084] The above description is merely an example and illustration of the present invention. Any modifications or additions made by those skilled in the art to the specific embodiments described, or any substitutions made in a similar manner, should fall within the protection scope of the present invention.

Claims

1. An environmentally friendly biodegradable wet wipe, comprising a wet wipe substrate and a wet wipe impregnation solution, characterized in that, The wet wipe substrate comprises the following raw materials in parts by weight: 67-83 parts modified polylactic acid fiber, 37-49 parts cotton fiber and 26-38 parts wood pulp fiber; The modified polylactic acid fiber is obtained by melt spinning from the following raw materials in parts by weight: 62-76 parts PLLA polylactic acid, 12-18 parts modified polyethylene glycol, 1-3 parts talc powder and 3-6 parts antioxidant. The modified polyethylene glycol is prepared through the following steps: A1. Under nitrogen protection, pyridine, polyethylene glycol and anhydrous toluene were added to the flask in sequence. After stirring evenly, the mixture was heated to 70°C, and then thionyl chloride was added dropwise. The mixture was kept at a constant temperature for 5 hours. After the reaction was completed, chlorinated polyethylene glycol was obtained. A2. Add 5,5-dimethylhydantoin, deionized water and sodium hydroxide to the flask in sequence. After stirring until the solute is dissolved, add chlorinated polyethylene glycol. Heat to 50°C and stir at a constant temperature for 4 hours. The reaction is complete and the intermediate product is obtained. A3. Add the intermediate product, tert-butanol and deionized water to the flask in sequence, stir well, then add sodium hypochlorite to the flask. Under light-protected conditions, stir the reaction at room temperature for 6 hours until the reaction is complete, and obtain modified polyethylene glycol.

2. The environmentally friendly biodegradable wet wipe according to claim 1, characterized in that, In step A1, the ratio of pyridine, polyethylene glycol, anhydrous toluene, and thionyl chloride is 2.1 g: 100 g: 200 mL: 29.7 g.

3. The environmentally friendly biodegradable wet wipe according to claim 1, characterized in that, In step A2, the ratio of 5,5-dimethylhydantoin, deionized water, sodium hydroxide, and chlorinated polyethylene glycol is 26.7 g: 150 mL: 9.6 g: 102.1 g.

4. The environmentally friendly biodegradable wet wipe according to claim 1, characterized in that, In step A3, the ratio of intermediate product, tert-butanol, deionized water, and sodium hypochlorite is 121.7g:80mL:70mL:14.8g.

5. The environmentally friendly biodegradable wet wipe according to claim 1, characterized in that, The wet wipe soaking solution comprises the following raw materials in parts by weight: 80-100 parts deionized water, 2-4 parts glycerol, 1-3 parts propylene glycol, 0.5-1.5 parts hyaluronic acid, and 0.3-0.5 parts preservative.

6. The environmentally friendly biodegradable wet wipe according to claim 5, characterized in that, The preservative is one of parabens, phenoxyethanol, and potassium sorbate.

7. A method for preparing an environmentally friendly biodegradable wet wipe according to any one of claims 1-6, characterized in that... This includes the following steps: Modified polylactic acid fiber, cotton fiber, and wood pulp fiber are laid out in layers in the order of upper, middle, and lower layers to form a fiber web. Then, a nonwoven fabric is formed using a hydroentangling process. The nonwoven fabric is dried, rolled up, cut, and then soaked in a wet wipe solution before being packaged to obtain environmentally friendly and biodegradable wet wipes.

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