Degradable wet tissue and production process thereof

Abstract

The invention relates to the field of wet wipes, and discloses a degradable wet wipe and a production process thereof.The degradable wet wipe comprises a degradable non-woven fabric base material and skin moisturizer, the degradable non-woven fabric base material is prepared from modified polylactic acid fibers and natural fibers through needling and shaping, and the skin moisturizer comprises glycerin, double-layer modified composite lipidosome and a humectant; the modified polylactic acid fiber is prepared by mixing modified titanium dioxide and polylactic acid, granulating and then melt-blowing and spinning, the modified titanium dioxide promotes flaky chitosan to be crosslinked into spheres by using an emulsion polymerization method, quaternization is performed, and then titanium dioxide nanoparticles are attached to the surface by using a hydrothermal method; according to the double-layer modified composite lipidosome, soybean lecithin is used as a main membrane material to construct baicalin-phytosterol ester composite lipidosome, and then chitosan and collagen peptide-sodium carboxymethyl cellulose are self-assembled layer by layer to wrap the surface of the composite lipidosome, so that the degradable wet tissue is prepared. Meanwhile, good oxidation resistance is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of wet wipes, and in particular relates to a degradable wet wipe and a production process thereof. Background Art

[0002] As a convenient cleaning product, wet wipes are widely used in personal care, household cleaning, and healthcare. Degradable wet wipes are products that, under certain conditions, can naturally degrade into harmless substances within a short period of time. Compared to traditional wet wipes, degradable wet wipes are more environmentally friendly and sustainable, making them a relatively environmentally friendly product.

[0003] The base material of wet wipes is typically composed of natural fibers, synthetic fibers, or a composite of both. As consumer demand for wet wipes diversifies, performance requirements are increasingly stringent, particularly in terms of absorbency, flexibility, skin-friendliness, and environmental friendliness. Existing spunlace nonwovens used in wet wipes suffer from shortcomings such as poor biodegradability, limited flexibility, and insufficient antibacterial properties, requiring further improvement. Furthermore, simple antibacterial properties no longer meet market demand and suffer from limited functionality. Summary of the Invention

[0004] In order to solve the deficiencies mentioned in the above background technology, the purpose of the present invention is to provide a degradable wet wipe and a production process thereof. The prepared degradable wet wipe is mild and non-irritating, has high water absorption and antibacterial properties, and has good antioxidant capacity.

[0005] The purpose of the present invention can be achieved through the following technical solutions: A degradable wet wipe comprising a degradable non-woven fabric substrate and a skin care lotion, wherein the degradable non-woven fabric substrate is made by needle-punching modified polylactic acid fiber and natural fiber, and the skin care lotion comprises the following components in parts by weight: 20-40 parts of glycerin, 1-5 parts of double-layer modified composite liposomes, 4-7 parts of a moisturizer, and 65-80 parts of deionized water; The modified polylactic acid fiber is made by mixing modified titanium dioxide and polylactic acid, granulating them, and then melt-blowing them. The modified titanium dioxide is made by promoting the cross-linking of flaky chitosan into spheres through emulsion polymerization and introducing trimethylammonium chloride for quaternization. Then, titanium dioxide nanoparticles are attached to the surface of the quaternized chitosan microspheres through a hydrothermal method. The double-layer modified composite liposomes are prepared by using soybean lecithin as the main membrane material, and employing a thin film-ultrasound method to construct baicalin-phytosterol ester composite liposomes. Subsequently, chitosan and collagen peptide-sodium carboxymethyl cellulose are self-assembled and wrapped layer by layer on the surface of the composite liposomes based on electrostatic interactions.

[0006] Preferably, the moisturizing agent comprises the following components in parts by weight: 2 to 5 parts of butylene glycol, 0.3 to 1 part of xanthan gum, 0.1 to 1 part of trehalose, 0.1 to 0.5 part of sorbitol, 0.1 to 0.5 part of hydroxyethyl cellulose, 0.01 to 0.05 part of Centella asiatica extract, and 0.01 to 0.03 part of sodium hyaluronate.

[0007] Preferably, the natural fiber is one or more combinations of cotton fiber, hemp fiber, bamboo fiber, and wood pulp fiber; and the mass ratio of the modified polylactic acid fiber to the natural fiber is 1:2-5.

[0008] Preferably, the method for preparing the double-layer modified composite liposome comprises the following steps: A. Place linoleic acid and phytosterols in a reactor, heat and dissolve them, then add sodium bisulfate, continue heating to 110-125°C, and reflux under condensation for 8-10 hours. After the reaction is complete, cool to room temperature, wash with deionized water to remove the sodium bisulfate, then wash with anhydrous ethanol to remove unreacted products, and finally remove the anhydrous ethanol by rotary evaporation to prepare phytosterol linoleate; B. Soybean lecithin, phytosterol linoleate, and baicalin were ultrasonically mixed and dissolved in methanol, and then the methanol was slowly removed using a rotary evaporator placed in a constant temperature water bath at 40°C until a thin film was formed. Subsequently, phosphate buffer with a pH of 7.4 was added and hydrated using an ultrasonic water bath. The hydrated suspension was further ultrasonically disrupted using an ultrasonic disruptor to prepare baicalin-phytosterol ester complex liposomes; C. Dissolve chitosan in acetic acid solution to obtain a chitosan solution, slowly inject baicalin-phytosterol ester composite liposomes into the chitosan solution while stirring, and continue stirring at room temperature for 55-70 minutes after the injection is completed to prepare chitosan-modified composite liposomes; D. Take 2-(N-morpholino)ethanesulfonic acid buffer solution with a pH of 5.5 in a reactor, add sodium carboxymethyl cellulose and stir to mix evenly, then add 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide, stir and activate for 0.5-1h, then add collagen peptide powder, place at 37-45°C and continue stirring to react for 20-24h. After the reaction is completed, dialyze and freeze-dry to prepare collagen peptide-sodium carboxymethyl cellulose; E. Dissolve collagen peptide-sodium carboxymethyl cellulose in deionized water to obtain a mixed solution. Slowly inject chitosan-modified composite liposomes into the mixed solution while stirring. After the injection is completed, continue stirring at room temperature for 55-70 minutes to prepare double-layer modified composite liposomes.

[0009] Preferably, the preparation method of the modified polylactic acid fiber comprises the following steps: (1) Chitosan was dissolved in acetic acid solution to obtain chitosan solution, Span 80 and liquid paraffin were mixed evenly, the mixture was heated to 45-55°C, chitosan solution and glutaraldehyde were added, and after the cross-linking reaction was completed, the mixture was washed and dried to prepare chitosan microspheres; (2) Chitosan microspheres and isopropanol were mixed, trimethylammonium chloride was added dropwise, and the mixture was reacted at 60-75°C for 0.5-1h. After freeze-drying, the mixture was washed with deionized water and ethanol to obtain quaternized chitosan microspheres. Then, deionized water was added to the quaternized chitosan microspheres, urea and titanium oxysulfate, and the mixture was stirred evenly. The mixture was transferred to a reactor and reacted at 155-160°C for 3-3.5h. Finally, the mixture was washed and dried to obtain modified titanium dioxide. (3) Polylactic acid and modified titanium dioxide are mixed and poured into a twin-screw extruder for mixing and granulation to obtain modified polylactic acid masterbatch, and then the modified polylactic acid masterbatch is melt-blown spun to prepare modified polylactic acid fiber.

[0010] Preferably, in step (2), the addition ratio of quaternized chitosan microspheres, deionized water, urea and titanyl sulfate is 0.15-0.2 g: 40-60 mL: 1 g: 0.08-0.1 g.

[0011] Preferably, in step (3), the mass ratio of polylactic acid to modified titanium dioxide is 1:0.5-1.

[0012] Preferably, in step (3), the operating temperature of the twin-screw extruder is 165-175° C., the feed rate is 4-5 r / min, and the extrusion rate is 45-60 r / min.

[0013] Preferably, the process parameters of melt-blown spinning in step (3) are: hot air pressure of 0.3-0.6 MPa, extruder pressure of 3.5-4 MPa, and operating temperature of 160-230°C.

[0014] A production process for biodegradable wet wipes, comprising the following steps: S1. Weigh each component by weight, mix butylene glycol, xanthan gum, trehalose, sorbitol, hydroxyethyl cellulose, Centella asiatica extract, and sodium hyaluronate to obtain a moisturizing agent, then add glycerin, bilayer modified composite liposomes, and the moisturizing agent to deionized water and stir to obtain a skin care lotion; S2, mixing modified polylactic acid fiber and natural fiber, and using a fiber decompressor to decompose the mixed fiber, and then transferring the mixed fiber to a sheet making device to disperse it evenly and form a sheet structure. After the sheet making is completed, it is naturally dried in the shade and needle punched to prepare a biodegradable non-woven fabric substrate; S3. Dipping or spraying the obtained skin care liquid on a degradable non-woven fabric substrate to prepare a degradable wet wipe.

[0015] Beneficial effects of the present invention: The present invention uses linoleic acid and phytosterols to prepare phytosterol linoleate, then uses soybean lecithin as the main membrane material, and uses a thin film-ultrasound method to construct baicalin-phytosterol ester composite liposomes. Subsequently, based on electrostatic interaction, collagen peptide-sodium carboxymethyl cellulose can interact with chitosan to form a cation-anion complex that self-assembles layer by layer and wraps on the outer surface of the composite liposome to prepare a double-layered composite liposome modified with chitosan and collagen peptide-sodium carboxymethyl cellulose, thereby forming a barrier around the composite liposome. The stability and antioxidant activity of the composite liposomes are improved, while the protective layer formed by the double-layer modification has a certain sustained-release effect on the composite liposome core material. Furthermore, baicalin, as a flavonoid active ingredient, has multiple skincare benefits, including anti-inflammatory, antioxidant, antibacterial, whitening, and barrier repair. The preparation of baicalin-phytosterol ester composite liposomes can effectively reduce substance loss and protect the active ingredients from external stressors (such as moisture, light, and oxidation). Furthermore, the incorporation of phytosterol esters and baicalin in the composite liposomes have a synergistic antioxidant effect. The present invention incorporates the double-layer modified composite liposomes into skincare lotion components, resulting in a mild, non-irritating effect. It exhibits excellent skincare efficacy, as well as antibacterial and anti-inflammatory effects. Furthermore, the skincare lotion components are more stable, allowing for long-term storage and extending the shelf life of the lotion.

[0016] The present invention utilizes an emulsion polymerization method to connect amino groups and hydroxyl groups in chitosan through the aldehyde group of glutaraldehyde, promotes the cross-linking of flaky chitosan into spheres, and increases its specific surface area. Trimethylammonium chloride is then introduced into chitosan microspheres for quaternization, prompting the formation of irregular depressions on the surface of the chitosan microspheres, thereby further enhancing the specific surface area. Subsequently, a hydrothermal method is used to enable titanium dioxide to adhere to the surface of the quaternized chitosan microspheres to prepare modified titanium dioxide. The modified titanium dioxide is mixed with polylactic acid and granulated, and then melt-blown spinning is performed to prepare modified polylactic acid fibers. The chitosan has the advantages of biodegradability, water solubility, adhesion, antibacterial properties, etc. At the same time, the modified titanium dioxide in the polylactic acid matrix absorbs water, significantly enhancing the hydrophilicity and water absorption of the material, so that a large amount of OH - And water molecules attack the ester bonds of polylactic acid, causing molecular chain breakage and accelerating the water degradation process of polylactic acid. Then, the present invention needle-punches the modified polylactic acid fiber and natural fiber into a degradable non-woven fabric substrate with good air permeability and moisture permeability. DETAILED DESCRIPTION

[0017] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0018] Example 1 A method for preparing a double-layer modified composite liposome comprises the following steps: A. Place linoleic acid and phytosterol in a molar ratio of 3:1 in a reactor, heat and dissolve, then add 2% sodium bisulfate, continue heating to 120°C, and reflux under condensation for 8 hours. After the reaction is completed, cool to room temperature, wash with deionized water to remove sodium bisulfate, then wash with anhydrous ethanol to remove unreacted matter, and finally remove anhydrous ethanol by rotary evaporation to prepare phytosterol linoleate; B. 50 mg of soybean lecithin, 5 mg of phytosterol linoleate, and 1 mg of baicalin were dissolved in 6 mL of methanol by ultrasonic mixing. The methanol was then slowly removed by rotary evaporation in a 40°C constant temperature water bath until a thin film was formed. 10 mL of phosphate buffer with a pH of 7.4 was then added and hydrated in an ultrasonic water bath. The hydrated suspension was further ultrasonically disrupted using an ultrasonic disruptor to prepare baicalin-phytosterol ester complex liposomes. C. Chitosan was dissolved in a 1% by volume acetic acid solution to obtain a 0.2% chitosan solution. Baicalin-phytosterol ester composite liposomes were slowly injected into the chitosan solution at a volume ratio of 1:1 while stirring. After the injection, stirring was continued at room temperature for 60 minutes to prepare chitosan-modified composite liposomes. D. Take 50 mL of 2-(N-morpholino)ethanesulfonic acid buffer solution with a pH of 5.5 and a concentration of 0.2 mol / L in a reactor, add 0.6 g of sodium carboxymethyl cellulose and stir to mix evenly, then add 0.38 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 0.11 g of N-hydroxysuccinimide, stir and activate for 1 hour, then add 0.6 g of collagen peptide powder, place at 40 ° C and continue stirring to react for 20 hours. After the reaction is completed, dialyze and freeze-dry to prepare collagen peptide-sodium carboxymethyl cellulose; E. Dissolve collagen peptide-sodium carboxymethyl cellulose in deionized water to obtain a mixture with a concentration of 0.02%. Slowly inject chitosan-modified composite liposomes into the mixture at a volume ratio of 1:1 while stirring. After the injection is completed, continue stirring at room temperature for 60 minutes to prepare double-layer modified composite liposomes.

[0019] Example 2 A method for preparing modified polylactic acid fiber comprises the following steps: (1) 1.5 g of chitosan was dissolved in 100 mL of 1.5% acetic acid solution to obtain chitosan solution. 4 mL of Span 80 and 96 mL of liquid paraffin were mixed evenly, and the mixture was heated to 50 °C. 10 mL of chitosan solution and 0.4 mL of glutaraldehyde were added. After the cross-linking reaction was completed, the mixture was washed and dried to obtain chitosan microspheres. (2) 0.5 g of chitosan microspheres were mixed with 10 mL of isopropanol, 2 mL of trimethylammonium chloride was added dropwise, and the mixture was reacted at 70 ° C for 1 h. After freeze-drying, the mixture was washed with deionized water and ethanol to obtain quaternized chitosan microspheres. Then, 40 mL of deionized water was added with 0.15 g of quaternized chitosan microspheres, 0.8 g of urea and 0.08 g of titanyl sulfate. After stirring evenly, the mixture was transferred to a reactor and reacted at 160 ° C for 3 h. Finally, the mixture was washed and dried to prepare modified titanium dioxide. (3) Polylactic acid and modified titanium dioxide were mixed in a mass ratio of 1:0.8 and poured into a twin-screw extruder for mixing and granulation. The working temperature was 170°C, the feed rate was 4 r / min, and the extrusion rate was 50 r / min to obtain modified polylactic acid masterbatch. The modified polylactic acid masterbatch was then melt-blown spun at a hot air pressure of 0.4 MPa, an extruder pressure of 3.8 MPa, and a working temperature of 199°C to prepare modified polylactic acid fiber.

[0020] Example 3 A production process for biodegradable wet wipes comprises the following steps: S1. Weigh each component by weight, mix 2.2 parts of butylene glycol, 0.5 parts of xanthan gum, 0.15 parts of trehalose, 0.2 parts of sorbitol, 0.1 parts of hydroxyethyl cellulose, 0.01 parts of Centella asiatica extract, and 0.01 parts of sodium hyaluronate to obtain a moisturizing agent, then add 25 parts of glycerin, 1.2 parts of the double-layer modified composite liposomes prepared in Example 1, and 4.1 parts of the moisturizing agent to 68 parts of deionized water, stir evenly, and prepare a skin care lotion; S2. The modified polylactic acid fiber and cotton fiber prepared in Example 2 are mixed in a mass ratio of 1:2.5, and the mixed fiber is decomposed using a fiber decompressor. The mixed fiber is then transferred to a sheet making device and evenly dispersed to form a sheet structure. After the sheet making is completed, the sheet is naturally dried in the shade and needle punched to form a degradable non-woven fabric substrate; S3. Impregnate the obtained skin care liquid on a degradable non-woven fabric substrate to prepare a degradable wet wipe.

[0021] Example 4 A production process for biodegradable wet wipes comprises the following steps: S1. Weigh each component by weight, mix 3 parts of butylene glycol, 0.5 parts of xanthan gum, 0.5 parts of trehalose, 0.2 parts of sorbitol, 0.2 parts of hydroxyethyl cellulose, 0.02 parts of Centella asiatica extract, and 0.02 parts of sodium hyaluronate to obtain a moisturizing agent, then add 34 parts of glycerin, 2.4 parts of the double-layer modified composite liposomes prepared in Example 1, and 5.5 parts of the moisturizing agent to 72 parts of deionized water, stir evenly, and prepare a skin care lotion; S2. The modified polylactic acid fiber and cotton fiber prepared in Example 2 are mixed in a mass ratio of 1:4, and the mixed fiber is decomposed using a fiber decompressor. The mixed fiber is then transferred to a sheet making machine and dispersed evenly to form a sheet structure. After the sheet is made, it is naturally dried in the shade and needle punched to prepare a degradable non-woven fabric substrate; S3. Impregnate the obtained skin care liquid on a degradable non-woven fabric substrate to prepare a degradable wet wipe.

[0022] Example 5 A production process for biodegradable wet wipes comprises the following steps: S1. Weigh each component by weight, and evenly mix 4.7 parts of butylene glycol, 0.8 parts of xanthan gum, 0.7 parts of trehalose, 0.4 parts of sorbitol, 0.4 parts of hydroxyethyl cellulose, 0.04 parts of Centella asiatica extract, and 0.03 parts of sodium hyaluronate to obtain a moisturizing agent. Then, add 38 parts of glycerin, 4.1 parts of the double-layer modified composite liposomes prepared in Example 1, and 6.7 parts of the moisturizing agent to 79 parts of deionized water, stir evenly, and prepare a skin care lotion. S2. The modified polylactic acid fiber and cotton fiber prepared in Example 2 are mixed in a mass ratio of 1:5, and the mixed fiber is decomposed using a fiber decompressor. The mixed fiber is then transferred to a sheet making machine and dispersed evenly to form a sheet structure. After the sheet making is completed, the sheet is naturally dried in the shade and needle punched to form a degradable non-woven fabric substrate; S3. Impregnate the obtained skin care liquid on a degradable non-woven fabric substrate to prepare a degradable wet wipe.

[0023] Comparative Example 1 A production process for biodegradable wet wipes comprises the following steps: S1. Weigh each component by weight, and evenly mix 4.7 parts of butylene glycol, 0.8 parts of xanthan gum, 0.7 parts of trehalose, 0.4 parts of sorbitol, 0.4 parts of hydroxyethyl cellulose, 0.04 parts of Centella asiatica extract, and 0.03 parts of sodium hyaluronate to obtain a moisturizing agent. Then, add 38 parts of glycerin, 4.1 parts of baicalin-phytosterol ester complex liposomes prepared in Example 1, and 6.7 parts of the moisturizing agent to 79 parts of deionized water, stir evenly, and prepare a skin care lotion. S2. The modified polylactic acid fiber and cotton fiber prepared in Example 2 are mixed in a mass ratio of 1:5, and the mixed fiber is decomposed using a fiber decompressor. The mixed fiber is then transferred to a sheet making machine and dispersed evenly to form a sheet structure. After the sheet making is completed, the sheet is naturally dried in the shade and needle punched to form a degradable non-woven fabric substrate; S3. Impregnate the obtained skin care liquid on a degradable non-woven fabric substrate to prepare a degradable wet wipe.

[0024] Comparative Example 2 A production process for biodegradable wet wipes comprises the following steps: S1. Weigh each component by weight, and evenly mix 4.7 parts of butylene glycol, 0.8 parts of xanthan gum, 0.7 parts of trehalose, 0.4 parts of sorbitol, 0.4 parts of hydroxyethyl cellulose, 0.04 parts of Centella asiatica extract, and 0.03 parts of sodium hyaluronate to obtain a moisturizing agent. Then, add 38 parts of glycerin and 6.7 parts of the moisturizing agent to 79 parts of deionized water, stir evenly, and prepare a skin care lotion. S2. The modified polylactic acid fiber and cotton fiber prepared in Example 2 are mixed in a mass ratio of 1:5, and the mixed fiber is decomposed using a fiber decompressor. The mixed fiber is then transferred to a sheet making machine and dispersed evenly to form a sheet structure. After the sheet making is completed, the sheet is naturally dried in the shade and needle punched to form a degradable non-woven fabric substrate; S3. Impregnate the obtained skin care liquid on a degradable non-woven fabric substrate to prepare a degradable wet wipe.

[0025] Comparative Example 3 A production process for biodegradable wet wipes comprises the following steps: S1. Weigh each component by weight, and evenly mix 4.7 parts of butylene glycol, 0.8 parts of xanthan gum, 0.7 parts of trehalose, 0.4 parts of sorbitol, 0.4 parts of hydroxyethyl cellulose, 0.04 parts of Centella asiatica extract, and 0.03 parts of sodium hyaluronate to obtain a moisturizing agent. Then, add 38 parts of glycerin, 4.1 parts of the double-layer modified composite liposomes prepared in Example 1, and 6.7 parts of the moisturizing agent to 79 parts of deionized water, stir evenly, and prepare a skin care lotion. S2, the modified polylactic acid fiber and the cotton fiber are mixed in a mass ratio of 1:5, and the mixed fiber is decomposed by a fiber decompressor, and then the mixed fiber is transferred to a sheet making device to be evenly dispersed and form a sheet structure. After the sheet is completed, it is naturally dried in the shade and needle punched to prepare a degradable non-woven fabric substrate; S3. Impregnate the obtained skin care liquid on a degradable non-woven fabric substrate to prepare a degradable wet wipe.

[0026] The preparation method of the modified polylactic acid fiber in step S2 comprises the following steps: Polylactic acid and nano-titanium dioxide were mixed in a mass ratio of 1:0.8 and poured into a twin-screw extruder for mixing and granulation. The working temperature was 170°C, the feed rate was 4r / min, and the extrusion rate was 50r / min to obtain modified polylactic acid masterbatch. The modified polylactic acid masterbatch was then melt-blown spun with a hot air pressure of 0.4MPa, an extruder pressure of 3.8MPa, and a working temperature of 199°C to prepare modified polylactic acid fiber.

[0027] Performance testing A. The double-layer modified composite liposomes and baicalin-phytosterol ester composite liposomes prepared in Example 1 were tested for sustained-release performance: the test results showed that the double-layer modified composite liposomes released 20.8% of baicalin within the first 30 days, while the cumulative release rate of baicalin-phytosterol ester composite liposomes was 26.5%. After 60 days, the cumulative release rate of the double-layer modified composite liposomes was 71.4%, while the cumulative release rate of baicalin-phytosterol ester composite liposomes was 86.5%, indicating that the stability of the composite liposomes modified with chitosan and collagen peptide-sodium carboxymethyl cellulose was improved, and the release of baicalin could be better controlled.

[0028] B. The degradable non-woven fabric substrates prepared in Examples 3-5 and Comparative Example 3 were subjected to performance testing: (1) Degradation performance test: The sample was dried and weighed, and the initial mass (M0) was recorded. The sample was then buried at the bottom of a flower pot, covered with rotten leaves and fertilizer, and the flower pot was placed outdoors for a degradation experiment. After 40 days, the sample was removed from the flower pot, cleaned, dried, weighed, and the mass (M1) was recorded. The formula for calculating the weight loss rate of the sample is: weight loss rate = (M0-M1) / M0×100%. The data results are shown in Table 1.

[0029] (2) Water absorption test: The sample was weighed after absorbing water (W0), and then weighed after drying (W1). The water absorption rate after 48 hours of water absorption was tested: water absorption rate = (W0-W1) / W0×100%. The data results are shown in Table 1.

[0030] (3) Breaking strength test: The breaking strength test was carried out in accordance with GB / T 24218.3-2010, and the data results are shown in Table 1.

[0031] (4) Antibacterial performance test: The test was carried out in accordance with the GB 15979-2002 method. The test bacteria were Escherichia coli. The antibacterial rate was evaluated according to the following standards: Grade A, bactericidal rate ≥ 95%; Grade B: 95% > bactericidal rate ≥ 90%; Grade C: bactericidal rate < 90%. The data results are shown in Table 1.

[0032] Table 1 Test results of biodegradable non-woven fabric substrate performance

[0033] From the data results in Table 1, it can be seen that the degradable non-woven fabric substrates prepared in Examples 3-5 of the present invention have good breaking strength, are biodegradable, environmentally friendly, and have high water absorption and antibacterial grades. In Comparative Example 3, polylactic acid and nano-titanium dioxide are simply mixed, and the measured breaking strength is lower than that of Examples 3-5. The possible reason is that the agglomeration of nano-titanium dioxide causes its mechanical properties to decrease. At the same time, the measured water absorption and antibacterial grades are worse than those of Examples 3-5, indicating that the prepared modified titanium dioxide has improved the water absorption and antibacterial properties of the substrate to a certain extent.

[0034] C. The biodegradable wet wipes prepared in Examples 3-5 and Comparative Examples 1-3 were subjected to performance testing: (1) The antioxidant capacity test uses the ORAC analysis method. ORAC is the abbreviation of oxidative free radical absorbance capacity, which is also called antioxidant capacity. It is based on the principle that free radicals destroy fluorescent probes and cause changes in fluorescence intensity. Trolox, a water-soluble analog of vitamin E, is used as the quantitative standard. The analysis is performed using a fluorescence microplate analyzer. The data results are shown in Table 2.

[0035] (2) Antibacterial performance test: The test was carried out in accordance with the GB15979-2002 method. The test bacteria were Escherichia coli. The antibacterial rate was evaluated according to the following standards: Grade A, bactericidal rate ≥ 95%; Grade B: 95% > bactericidal rate ≥ 90%; Grade C: bactericidal rate < 90%. The data results are shown in Table 2.

[0036] Table 2 Test results of biodegradable wet wipes performance

[0037] It can be seen from the data in Table 2 that the degradable wet wipes prepared in Examples 3-5 of the present invention have good antioxidant capacity and antibacterial properties. In Comparative Example 1, the baicalin-phytosterol ester composite liposomes were not double-layer modified, and the average antioxidant capacity measured was worse than that of Examples 3-5. In Comparative Example 2, no double-layer modified composite liposomes were added, and the average antioxidant capacity and antibacterial grade measured were significantly lower than those of Examples 3-5, indicating that the addition of double-layer modified composite liposomes improved the antioxidant capacity and antibacterial properties of the degradable wet wipes. The antibacterial grade measured in Comparative Example 3 was lower than that of Examples 3-5, which may be due to the agglomeration of nano-titanium dioxide and the failure to introduce quaternized chitosan microspheres.

[0038] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these 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 any one or more embodiments or examples.

[0039] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention, and such changes and modifications fall within the scope of the invention as claimed.

Claims

1. A degradable wet wipe, characterized in that: The invention comprises a degradable non-woven fabric substrate and a skin care lotion, wherein the degradable non-woven fabric substrate is made by needle-punching modified polylactic acid fiber and natural fiber, and the skin care lotion comprises the following components by weight: 20-40 parts of glycerin, 1-5 parts of double-layer modified composite liposomes, 4-7 parts of moisturizer, and 65-80 parts of deionized water; The modified polylactic acid fiber is made by mixing modified titanium dioxide and polylactic acid, granulating them, and then melt-blowing them. The modified titanium dioxide is made by promoting the cross-linking of flaky chitosan into spheres through emulsion polymerization and introducing trimethylammonium chloride for quaternization. Then, titanium dioxide nanoparticles are attached to the surface of the quaternized chitosan microspheres through a hydrothermal method. The double-layer modified composite liposomes are prepared by using soybean lecithin as the main membrane material, and employing a thin film-ultrasound method to construct baicalin-phytosterol ester composite liposomes. Subsequently, chitosan and collagen peptide-sodium carboxymethyl cellulose are self-assembled and wrapped layer by layer on the surface of the composite liposomes based on electrostatic interactions.

2. The degradable wet wipes according to claim 1, characterized in that: The moisturizing agent comprises the following components in parts by weight: 2-5 parts of butylene glycol, 0.3-1 part of xanthan gum, 0.1-1 part of trehalose, 0.1-0.5 part of sorbitol, 0.1-0.5 part of hydroxyethyl cellulose, 0.01-0.05 part of Centella asiatica extract, and 0.01-0.03 part of sodium hyaluronate.

3. The degradable wet wipes according to claim 1, characterized in that The natural fiber is one or more combinations of cotton fiber, hemp fiber, bamboo fiber, and wood pulp fiber; and the mass ratio of the modified polylactic acid fiber to the natural fiber is 1:2-5.

4. The degradable wet wipes according to claim 1, characterized in that: The preparation method of the double-layer modified composite liposome comprises the following steps: A. Place linoleic acid and phytosterols in a reactor, heat and dissolve them, then add sodium bisulfate, continue heating to 110-125°C, and reflux under condensation for 8-10 hours. After the reaction is complete, cool to room temperature, wash with deionized water to remove the sodium bisulfate, then wash with anhydrous ethanol to remove unreacted products, and finally remove the anhydrous ethanol by rotary evaporation to prepare phytosterol linoleate; B. Soybean lecithin, phytosterol linoleate, and baicalin were ultrasonically mixed and dissolved in methanol, and then the methanol was slowly removed using a rotary evaporator placed in a constant temperature water bath at 40°C until a thin film was formed. Subsequently, phosphate buffer with a pH of 7.4 was added and hydrated using an ultrasonic water bath. The hydrated suspension was further ultrasonically disrupted using an ultrasonic disruptor to prepare baicalin-phytosterol ester complex liposomes; C. Dissolve chitosan in acetic acid solution to obtain a chitosan solution, slowly inject baicalin-phytosterol ester composite liposomes into the chitosan solution while stirring, and continue stirring at room temperature for 55-70 minutes after the injection is completed to prepare chitosan-modified composite liposomes; D. Take 2-(N-morpholino)ethanesulfonic acid buffer solution with a pH of 5.5 in a reactor, add sodium carboxymethyl cellulose and stir to mix evenly, then add 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide, stir and activate for 0.5-1h, then add collagen peptide powder, place at 37-45°C and continue stirring to react for 20-24h. After the reaction is completed, dialyze and freeze-dry to prepare collagen peptide-sodium carboxymethyl cellulose; E. Dissolve collagen peptide-sodium carboxymethyl cellulose in deionized water to obtain a mixed solution. Slowly inject chitosan-modified composite liposomes into the mixed solution while stirring. After the injection is completed, continue stirring at room temperature for 55-70 minutes to prepare double-layer modified composite liposomes.

5. The degradable wet wipes according to claim 1, characterized in that: The preparation method of the modified polylactic acid fiber comprises the following steps: (1) Chitosan was dissolved in acetic acid solution to obtain chitosan solution, Span 80 and liquid paraffin were mixed evenly, the mixture was heated to 45-55°C, chitosan solution and glutaraldehyde were added, and after the cross-linking reaction was completed, the mixture was washed and dried to prepare chitosan microspheres; (2) Chitosan microspheres and isopropanol were mixed, trimethylammonium chloride was added dropwise, and the mixture was reacted at 60-75°C for 0.5-1h. After freeze-drying, the mixture was washed with deionized water and ethanol to obtain quaternized chitosan microspheres. Then, deionized water was added to the quaternized chitosan microspheres, urea and titanium oxysulfate, and the mixture was stirred evenly. The mixture was transferred to a reactor and reacted at 155-160°C for 3-3.5h. Finally, the mixture was washed and dried to obtain modified titanium dioxide. (3) Polylactic acid and modified titanium dioxide are mixed and poured into a twin-screw extruder for mixing and granulation to obtain modified polylactic acid masterbatch, and then the modified polylactic acid masterbatch is melt-blown spun to prepare modified polylactic acid fiber.

6. The degradable wet wipes according to claim 5, characterized in that: In the step (2), the addition ratio of quaternized chitosan microspheres, deionized water, urea and titanyl sulfate is 0.15-0.2 g:40-60 mL:1 g:0.08-0.1 g.

7. The degradable wet wipes according to claim 5, characterized in that: In the step (3), the mass ratio of polylactic acid to modified titanium dioxide is 1:0.5~1.

8. The degradable wet wipes according to claim 5, characterized in that: In step (3), the operating temperature of the twin-screw extruder is 165-175° C., the feed rate is 4-5 r / min, and the extrusion rate is 45-60 r / min.

9. The degradable wet wipes according to claim 5, characterized in that: The process parameters of melt-blown spinning in step (3) are: hot air pressure of 0.3-0.6 MPa, extruder pressure of 3.5-4 MPa, and operating temperature of 160-230°C.

10. A production process for the biodegradable wet wipes according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Weigh each component by weight, mix butylene glycol, xanthan gum, trehalose, sorbitol, hydroxyethyl cellulose, Centella asiatica extract, and sodium hyaluronate to obtain a moisturizing agent, then add glycerin, bilayer modified composite liposomes, and the moisturizing agent to deionized water and stir to obtain a skin care lotion; S2, mixing modified polylactic acid fiber and natural fiber, and using a fiber decompressor to decompose the mixed fiber, and then transferring the mixed fiber to a sheet making device to disperse it evenly and form a sheet structure. After the sheet making is completed, it is naturally dried in the shade and needle punched to prepare a biodegradable non-woven fabric substrate; S3. Dipping or spraying the obtained skin care liquid on a degradable non-woven fabric substrate to prepare a degradable wet wipe.

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