A chemical-free makeup removing soft tissue and a preparation method thereof

Abstract

The present application relates to a kind of chemical makeup-removing soft wipes and preparation method thereof, belong to the technical field of cosmetic products.The present application is with negative charge polyelectrolyte gel solution modification nano metal oxide, with positive charge polyelectrolyte gel solution modification mesoporous nano silicon oxide, two kinds of modified nanometer materials are mixed with core layer hydrophilic polymer and shell layer hydrophobic polymer respectively in spinning process, by coaxial spinning, three-stage traction stretching and cutting, functional short fiber is prepared, again by non-woven fabric processing technology and ultrasonic activation treatment is made into chemical makeup-removing soft wipes;When the soft wipes meet water, the built-in potential and nano channel between fiber core and shell, which are constructed by the two kinds of modified nanometer materials, can break the water molecule aggregation state and convert it into small molecule water, and small molecule water can quickly penetrate cosmetic oil film, so as to realize the "self-dissolution" makeup-removing effect without chemical solvent dependence.

Description

Technical Field

[0001] This invention belongs to the field of cosmetics technology, and in particular relates to a chemical-free makeup remover wipe and its preparation method. Background Technology

[0002] Traditional liquid makeup removers rely on surfactants, alcohol, and other chemical ingredients. Long-term use can easily damage the skin barrier, cause skin sensitivity, or irritate the eyes, and they are also inconvenient to carry. While existing wet makeup remover wipes solve the portability problem, they still contain chemical solvents. Not only do they not avoid the risks of dry skin and mite growth after makeup removal, but they also require rinsing with plenty of water.

[0003] For example, patent CN 117530898 A discloses a makeup remover wipe and its preparation method. Although it uses various plant extracts such as olive oil extract, aloe vera extract, soapberry extract, lavender extract, chamomile extract, or tea saponin, these ingredients are still chemical substances and fail to meet the requirement of makeup removal without chemical additives. Patent CN 110680757 A discloses a makeup remover wipe made of nanofiber fabric containing trace elements. It only modifies the fiber fabric to improve antibacterial and negative ion absorption functions, but does not address the core problem that absorbent fibers cannot effectively dissolve and remove cosmetics, especially makeup, and the makeup removal effect is not substantially improved.

[0004] Therefore, it is of great significance to develop a soft towel that combines makeup removal and skincare functions without chemical additives. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a chemical-free makeup remover wipe and its preparation method. The method involves modifying nano-metal oxides with a negatively charged polyelectrolyte gel solution and mesoporous nano-silica with a positively charged polyelectrolyte gel solution. During the spinning process, the two modified nanomaterials are mixed with a hydrophilic polymer in the core layer and a hydrophobic polymer in the shell layer. The mixture is then subjected to coaxial spinning, three-stage traction stretching, and cutting to obtain functional short fibers. These fibers are then processed using nonwoven fabric technology and ultrasonic activation to produce the chemical-free makeup remover wipe. When the wipe comes into contact with water, the built-in potential and nanochannels synergistically constructed by the two modified nanomaterials between the fiber core and shell can break the aggregation of water molecules, converting them into small water molecules. These small water molecules can quickly penetrate the cosmetic oil film, thus achieving a "self-dissolving" makeup removal effect without chemical solvent dependence.

[0006] The first objective of this invention is to provide a method for preparing a chemical-free makeup remover wipe, comprising the following steps: S1. Polypolyol, sodium hyaluronate and polystyrene sulfonic acid are dissolved in water to form a gel solution. Nano metal oxides are then added to the gel solution. The mixture is stirred, centrifuged and gelled in sequence to obtain negatively charged polyelectrolyte modified nano metal oxides. S2. Dissolve sodium alginate and polydiallyldimethylammonium chloride in water to form a gel solution. Continue to add mesoporous nano-silica to the gel solution. Perform the first stirring, the first centrifugation, the gelation treatment, the second stirring and the second centrifugation in sequence to obtain positively charged polyelectrolyte modified nano-silica. S3. The shell material is prepared by mixing the negatively charged polyelectrolyte-modified nano-metal oxide and hydrophobic polymer described in S1, and the core material is prepared by mixing the positively charged polyelectrolyte-modified nano-silica and hydrophilic polymer described in S2. The shell material and the core material are coaxially spun, and then subjected to three stages of traction stretching and cutting to obtain functional short fibers. S4. Functional short fibers are prepared into non-woven fabric substrate by hot air bonding method, and then the non-woven fabric substrate is subjected to ultrasonic activation treatment to form a nano-micro rough structure, thus obtaining the chemical-free makeup remover soft towel.

[0007] In one embodiment of the present invention, in S1, the polyol is selected from one or more of polyvinyl alcohol, polyethylene glycol and polyglycerol; And / or, the nano-metal oxide is selected from one or more of zinc oxide, titanium oxide, aluminum oxide and zirconium oxide.

[0008] In one embodiment of the present invention, in S1, the mass ratio of the polyol, sodium hyaluronate and polystyrene sulfonic acid is 1.0:(0.3-1.0):(2.0-3.5). And / or, the concentration of the gel solution is 20 g / L-50 g / L; And / or, the mass percentage of the nano-metal oxide is 1%-4%.

[0009] In one embodiment of the present invention, in S1, the temperature of the gelation treatment is 30°C-60°C.

[0010] In one embodiment of the present invention, in S2, the mass ratio of sodium alginate to polydiallyldimethylammonium chloride is 1:(8-14). And / or, the concentration of the gel solution is 50 g / L-80 g / L; And / or, the mesoporous nano-silica accounts for 1%-4% of the mass.

[0011] In one embodiment of the present invention, in S2, the gelation treatment uses a calcium chloride solution with a concentration of 9wt%-11wt%.

[0012] In one embodiment of the present invention, in S3, the hydrophobic polymer is selected from one or more of polyethylene, polypropylene, polylactic acid and polyamide; And / or, the hydrophilic polymer is a polyhydroxy polyester; And / or, the mass percentage of negatively charged polyelectrolyte-modified nano-metal oxide in the shell material is 4%-6%; And / or, the mass percentage of the core material, positively charged polyelectrolyte-modified nano-silica, is 4%-6%.

[0013] In one embodiment of the present invention, in S3, the shell temperature of the coaxial spinning is 170°C-190°C and the core temperature is 195°C-205°C. And / or, the stretching speed of the three-segment traction stretching is 95mpm-105mpm; The initial drawing temperature is 50℃-65℃, and the draw ratio is 1.3-1.6 times; The second drawing temperature is 75℃-85℃, and the draw ratio is 2.1-2.6 times; The three-stage traction temperature is 41℃-46℃, and the draw ratio is 1.1-1.3 times. The three-stage traction stretching, through the matching of gradient temperature and draw parameters, can ensure that the two substrates of the shell and core are fully melted and bonded, avoid interface defects caused by the agglomeration of functional modified components, ensure good shell-core composite without separation, and allow functional components to be uniformly dispersed in the shell and core layers, thereby constructing a stable coaxial core-shell structure. This structure is the basis for the synergistic formation of built-in potential and nanochannels by the negatively charged polyelectrolyte-modified nano-metal oxide in the shell layer and the positively charged polyelectrolyte-modified nano-silica in the core layer, and ultimately becomes the key process support for the fiber to convert ordinary water into small molecule water.

[0014] In one embodiment of the present invention, in S4, the process parameters of the hot air bonding method are as follows: hot air temperature is 130℃-210℃, pressure difference is 0.4Pa-2Pa, and production speed is 20m / min-60m / min. And / or, the ultrasonic activation treatment has a frequency of 25kHz-40kHz, a power of 500W-600W, and a duration of 25s-35s.

[0015] In one embodiment of the present invention, in S4, the height of the nano-micro rough structure is 10μm-50μm and the spacing is 20μm-100μm; by ultrasonic activation treatment, the fiber surface undergoes micro-melting to form uniform micro-protrusions (i.e., nano-micro rough structure). This structure can effectively increase the surface roughness and specific surface area of ​​the nonwoven fabric, thereby improving its mechanical friction, physical adsorption and peeling synergy when in contact with makeup particles. It also complements the high permeability of small molecule water, ultimately achieving efficient physical makeup removal without relying on chemical solvents, and successfully producing a chemical-free makeup remover wipe with both soft texture and excellent makeup removal effect.

[0016] A second objective of this invention is to provide a chemical-free makeup remover wipe prepared by the method described above.

[0017] The technical solution of the present invention has the following advantages compared with the prior art: (1) The chemical-free makeup remover wipe of the present invention uses nano-modified bicomponent core-shell fiber as the core. Through functional modification of the fiber core-shell structure, a built-in potential and nanochannel are constructed between the core-shell interface. The fiber does not require electricity or additional energy. When it comes into contact with water, it can produce an instantaneous effect through the synergistic effect of the built-in potential and nanochannel, destroying the hydrogen bonds between water molecules and efficiently converting aggregated water into small molecule water with strong penetrating and dissolving effect on cosmetics. The nano metal oxides doped in the fiber shell have both catalytic antibacterial and mite-killing effects. At the same time, the sodium hyaluronate released by the shell can achieve instant hydration and promote the absorption of subsequent skin care products. The small molecule water itself also has certain antibacterial and anti-mite properties, which form a synergistic effect with the nano metal oxides.

[0018] (2) The preparation method described in this invention uses hot air bonding to make nano-modified bicomponent core-shell fibers into non-woven fabric substrates, and then uses ultrasonic activation treatment to form a nano-micro rough structure, which further increases the roughness and friction of the non-woven fabric surface. Combined with the high efficiency of small molecule water penetration and solubility, the two work together to easily achieve physical makeup removal without the need to add additional chemical solvents, effectively avoiding the risk of skin and eye irritation and allergies caused by chemical substances in traditional makeup removal products.

[0019] (3) The chemical-free makeup remover wipes described in this invention are extremely convenient to use and carry. In the dry state, they only need to be soaked in pure water to remove makeup. They are not restricted by liquids when traveling and are suitable for daily use, outdoor activities, business trips and other scenarios. They also integrate multiple functions such as physical makeup removal, antibacterial and anti-mite, instant hydration and promoting the absorption of skin care products, making them more practical. Attached Figure Description

[0020] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein: Figure 1 The image shows a scanning electron microscope (SEM) image of the cross-section of the functional short fiber in Test Example 1 of the present invention; the left image is Example 1 and the right image is Comparative Example 2. Figure 2 This is a particle size distribution diagram of water after soaking the functional short fibers in Test Example 2 of the present invention; where A is ordinary water, B is the example, and C is Comparative Example 1. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0022] In this invention, unless otherwise stated, the degree of polymerization of polyvinyl alcohol used in the embodiments of this invention is 1000.

[0023] In this invention, unless otherwise stated, the molecular weight of the polystyrene sulfonic acid used in the embodiments of this invention is approximately 70,000.

[0024] In this invention, unless otherwise stated, the ultrasonic fusion equipment used in the embodiments of this invention is modified from a conventional ultrasonic plastic welding machine with a mold containing bumps and grooves. Example 1

[0025] The chemical-free makeup remover wipes and their preparation method in this embodiment specifically include the following steps: S1. Preparation of negatively charged polyelectrolyte-modified nano zinc oxide: Polyvinyl alcohol, sodium hyaluronate and polystyrene sulfonic acid were dissolved in water at a mass ratio of 1.0:0.5:2.5 to prepare a negatively charged polyelectrolyte gel solution with a concentration of 30 g / L; nano zinc oxide was dispersed into the gel solution at a mass ratio of 2%, and after stirring and centrifugation, the resulting separation was placed in a 40℃ desiccator for surface gelation treatment to obtain negatively charged polyelectrolyte-modified nano zinc oxide; S2. Preparation of positively charged polyelectrolyte modified nano-silica: Sodium alginate and polydiallyldimethylammonium chloride were dissolved in water at a mass ratio of 1:10 to prepare a positively charged polyelectrolyte gel solution with a concentration of 60 g / L; mesoporous nano-silica was dispersed into the gel solution at a mass ratio of 2%; after stirring and centrifugation, the resulting separation was redispersed in a 10 wt% calcium chloride solution for gelation treatment, and then separated by stirring and centrifugation. The resulting separation was dried in a desiccator at 40℃ to obtain positively charged polyelectrolyte modified nano-silica; S3. Preparation of functional short fibers: During coaxial spinning, negatively charged polyelectrolyte-modified nano-zinc oxide is added to the polylactic acid substrate melt channel of the shell layer at a mass ratio of 5%, and positively charged polyelectrolyte-modified nano-silica is added to the polyhydroxy polyester substrate melt channel of the core layer at a mass ratio of 5%. The mixture is then extruded by a twin-screw extruder with the shell temperature controlled at 180℃ and the core temperature at 200℃. Subsequently, three-stage traction stretching is performed with a stretching speed of 100mpm. The first stretching temperature is 55℃ with a stretching ratio of 1.4 times, the second stretching temperature is 80℃ with a stretching ratio of 2.5 times, and the third stretching temperature is 42℃ with a stretching ratio of 1.2 times. The resulting functional short fibers have a diameter of 1.5D and a length of 38mm. S4. Preparation of chemical-free makeup remover wipes: Functional short fibers are prepared into a basis weight of 40g / m² using a hot air bonding method. 2 The nonwoven fabric substrate was prepared by controlling the hot air temperature at 130℃, the pressure difference at 0.6Pa, and the production speed at 50m / min. The nonwoven fabric substrate was laid flat on an ultrasonic welding machine and subjected to directional activation treatment for 30s under ultrasonic conditions at a frequency of 30kHz and a power of 550W to form a nano-micro rough structure with a height of about 15μm and a spacing of about 30μm, thus obtaining a chemical-free makeup remover wipe. Example 2

[0026] The process is basically the same as in Example 1, except that the preparation of the functional short fibers includes the following steps: In the coaxial spinning process, negatively charged polyelectrolyte-modified nano-zinc oxide is added to the shell polyamide substrate melt channel at a mass ratio of 5%, and positively charged polyelectrolyte-modified nano-silica is added to the core polyester substrate melt channel at a mass ratio of 5%. The mixture is then extruded by a twin-screw extruder with the shell temperature controlled at 180℃ and the core temperature at 200℃. Subsequently, it undergoes three-stage traction stretching with a stretching speed of 110mpm. The first traction temperature is 60℃ with a stretching ratio of 1.5 times, the second traction temperature is 80℃ with a stretching ratio of 2.2 times, and the third traction temperature is 45℃ with a stretching ratio of 1.2 times. After cutting, functional short fibers with a diameter of 2.0D and a length of 38mm are obtained. Example 3

[0027] The chemical-free makeup remover wipes and their preparation method in this embodiment specifically include the following steps: S1. Negatively charged polyelectrolyte-modified nano-zinc oxide: Polyvinyl alcohol, sodium hyaluronate, and polystyrene sulfonic acid were dissolved in water at a mass ratio of 1.0:0.8:3.0 to prepare a negatively charged polyelectrolyte gel solution with a concentration of 40 g / L; nano-zinc oxide was dispersed into the gel solution at a mass ratio of 3%, and after stirring and centrifugation, the resulting separation was placed in a 50℃ desiccator for surface gelation treatment to obtain negatively charged polyelectrolyte-modified nano-zinc oxide; S2. Positively charged polyelectrolyte modified nano-silica: Sodium alginate and polydiallyldimethylammonium chloride were dissolved in water at a mass ratio of 1:12 to prepare a positively charged polyelectrolyte gel solution with a concentration of 70 g / L. Mesoporous nano-silica was dispersed into the gel solution at a mass ratio of 3%. After stirring and centrifugation, the resulting separation was redispersed in a 10 wt% calcium chloride solution for gelation treatment. After stirring and centrifugation, the resulting separation was placed in a 50°C desiccator to dry, thus obtaining positively charged polyelectrolyte modified nano-silica.

[0028] S3. Preparation of functional short fibers: During coaxial spinning, negatively charged polyelectrolyte-modified nano-zinc oxide is added to the polylactic acid substrate melt channel of the shell layer at a mass ratio of 5%, and positively charged polyelectrolyte-modified nano-silica is added to the polyester substrate melt channel of the core layer at a mass ratio of 5%. The mixture is then extruded by a twin-screw extruder with the shell temperature controlled at 180℃ and the core temperature at 200℃. Subsequently, three-stage traction stretching is performed with a stretching speed of 100mpm. The first stretching temperature is 55℃ with a stretching ratio of 1.4 times, the second stretching temperature is 80℃ with a stretching ratio of 2.5 times, and the third stretching temperature is 42℃ with a stretching ratio of 1.2 times. The resulting functional short fibers have a diameter of 1.5D and a length of 38mm. S4. Preparation of chemical-free makeup remover wipes: Functional short fibers are prepared into a basis weight of 40g / m² using a hot air bonding method. 2 The nonwoven fabric substrate was prepared by controlling the hot air temperature at 130℃, the pressure difference at 0.6Pa, and the production speed at 50m / min. The nonwoven fabric substrate was laid flat on an ultrasonic welding machine and subjected to directional activation treatment for 30s under ultrasonic conditions at a frequency of 35kHz and a power of 550W to form a nano-micro rough structure with a height of about 15μm and a spacing of about 30μm, thus obtaining a chemical-free makeup remover wipe. Comparative Example 1

[0029] It is basically the same as Example 1, except that positively charged polyelectrolyte modified nano-silica is not added to the core polyester substrate. Comparative Example 2

[0030] The basic structure is the same as in Example 1, except that the three-stage traction stretching is adjusted to a single-stage traction stretching, that is, the stretching speed is set to 130 mpm, the temperature of the first stage is 80°C, and the stretching ratio is 4.8 times. Comparative Example 3

[0031] It is basically the same as Example 1, except that: no directional activation is performed. Test Example 1

[0032] Based on Example 1 and Comparative Example 2, the cross-sections of the functional short fibers were characterized by scanning electron microscopy, and the results are as follows: Figure 1 As shown. From Figure 1As can be seen, in Example 1, a distinct, continuous, uniform shell-core interface without any peeling or cracks is formed between the shell and core layers of the functional short fiber cross-section. This fully demonstrates that a stable coaxial core-shell structure was successfully constructed through coaxial spinning combined with a three-stage traction stretching process. The gradient temperature and stretching parameters matched under this process not only ensured the full melting and bonding of the two substrate layers of the shell and core, but also avoided interface bonding defects caused by the agglomeration of functional modified components, resulting in uniform dispersion of functional components in the shell and core layers. In contrast, Comparative Example 2, due to the use of a one-stage traction stretching process, showed no clear distinction between the shell and core interfaces in the cross-section of its functional short fiber. The interface was blurred and there were local peeling and loose structure phenomena. This was because the single high-temperature, high-ratio stretching caused uneven stress and mismatched melting states in the two substrate layers of the shell and core, making it impossible to form an effective interface bonding force, thereby destroying the integrity of the coaxial structure. Test Example 2

[0033] Based on Example 1 and Comparative Example 1, functional short fibers were immersed in an equal amount of ordinary water (particle size 166.5 nm). The particle size of the water after immersion was measured using a dynamic light scattering instrument. The results are as follows. Figure 2 As shown. From Figure 2 It can be seen that the particle size of water after soaking the functional short fibers in Example 1 becomes 78.38 nm, which is significantly smaller than that of ordinary water. In contrast, the particle size of water after soaking the functional short fibers in Comparative Example 1 is 153.6 nm, which is not much different from that of ordinary water. This result confirms that the formation of the built-in potential and nanochannels between the core and shell of the functional short fiber must rely on the addition of corresponding modified nano-oxides to both the core and shell layers. In Example 1, the negatively charged polyelectrolyte-modified nano-zinc oxide in the shell layer and the positively charged polyelectrolyte-modified nano-silica in the core layer form a synergistic effect to construct a stable built-in potential and nanochannels, which can instantly break the aggregation between water molecules and transform ordinary aggregated water into small molecule water. In contrast, Comparative Example 1, lacking the positively charged polyelectrolyte-modified nano-silica in the core layer, cannot form an effective built-in potential and complete nanochannels, and therefore cannot achieve a significant reduction in the particle size of water molecules. This further confirms the key role of dual-modified nano-oxides in constructing the special structure of functional short fibers and realizing the water molecule refinement function. Test Example 3

[0034] The antibacterial rate and other properties of the soft towels prepared in the examples and comparisons were tested: (1) Antibacterial rate test: According to GB 15979-2024 "Hygienic requirements for disposable sanitary products", Candida albicans ATCC 10231, Staphylococcus aureus ATCC 6538 and Escherichia coli ATCC 25922 were used as test strains. Each sample was contacted with the corresponding strain and the contact time was controlled to be 1 min. Then, the samples were cultured and counted according to the standard procedure, and the antibacterial rate of each sample against the three strains was calculated. (2) Dust mite inactivation rate test: According to GB / T24253-2009 "Evaluation of anti-mite performance of textiles", each sample was treated with dust mites and the contact time was controlled to be 60 min. Then, the dust mite inactivation rate of each sample was tested and calculated according to the standard procedure. (3) in water 17 O half-peak width test: Liquid NMR was used. After relevant pretreatment, the water content of each sample was measured by an NMR spectrometer. 17 The half-width at half maximum (WHM) of O is recorded, and the test results for each sample are recorded. Table 1 shows the final measured properties of the cotton towel: Table 1

[0035] As shown in Table 1, the chemical-free makeup remover wipes in the embodiments all exhibited significant antibacterial effects, with inhibition rates of over 95% against Escherichia coli, Staphylococcus aureus, and Candida albicans, and a dust mite inactivation rate exceeding 85%, demonstrating strong mite-proof performance. Simultaneously, in water... 17 The half-width at half-maximum (WWHM) of all samples is less than 80 Hz, which is within the range of small molecule water. This confirms that small molecule clusters of water have been successfully formed in the cotton towel system. This excellent performance is attributed to the fact that the embodiments, through specific functional component modification methods and process optimization, have constructed stable built-in potentials and nanochannels within the functional short fibers, providing core support for the realization of antibacterial, anti-mite, and water molecule refinement functions.

[0036] Comparing Example 1 and Comparative Example 1, it can be seen that Comparative Example 1, which did not add positively charged polyelectrolyte-modified nano-silica to the core polyester substrate, showed significantly reduced antibacterial rates against Escherichia coli, Staphylococcus aureus, and Candida albicans, as well as significantly reduced inactivation rates against house dust mites; in water 17 The half-width at half-maximum (WWHM) of O was 112 Hz, which does not conform to the WWHM range of small molecule water, indicating that small molecule water clusters were not formed. This suggests that the synergistic effect of positively charged polyelectrolyte-modified nano-silica and negatively charged polyelectrolyte-modified nano-zinc oxide is indispensable. Only through their combined action can a stable built-in potential and complete nanochannels be constructed, thereby effectively improving the antibacterial and anti-mite properties of the product and promoting the formation of small molecule water clusters.

[0037] Comparing Example 1 and Comparative Example 2, it can be seen that Comparative Example 2, which uses a single-stage traction stretching method, has a lower antibacterial rate and a lower dust mite inactivation rate than Example 1; in water 17The half-width at half-maximum (WWHM) of 108 Hz does not conform to the WWHM range of small molecule water, indicating the failure to form small molecule water clusters. This is because the one-stage high-temperature, high-ratio stretching process resulted in uneven stress and mismatched melting states between the two substrate layers of the shell and core, failing to form a clearly defined, tightly bonded coaxial core-shell structure. Instead, it led to blurred interfaces, localized delamination, and a loose structure, damaging the structural integrity of the functional short fibers and causing uneven distribution of functional components. This, in turn, affected the stable construction of the built-in potential and nanochannels, ultimately resulting in a significant decrease in product performance. In contrast, the three-stage traction stretching process, through gradient temperature and stretching parameter matching, ensured the full melting and bonding of the two substrate layers of the shell and core, while avoiding interfacial bonding defects caused by the agglomeration of functional modified components. This ensured the uniform dispersion of functional components in the shell and core layers, providing a process guarantee for the product to achieve the expected performance.

[0038] Comparing Example 1 and Comparative Example 3, it can be seen that Comparative Example 3, without ultrasonic directional activation treatment, has the same antibacterial rate as Example 1, and the dust mite inactivation rate is also the same as Example 1. 17 The half-peak width (WHM) of 73 Hz is close to that of 71 Hz in Example 1, which is within the range of small molecule water's WHM. This indicates that the ultrasonic directional activation treatment did not significantly affect the product's antibacterial and anti-mite properties or the formation of small molecule water clusters. This further confirms that the coaxial shell-core structure of the functional short fibers and the synergistic effect of the core-shell dual-modified nano-oxides are the key factors determining the product's core performance. The ultrasonic directional activation treatment mainly affects the subsequent structural optimization of the nonwoven fabric substrate, enhancing physical friction and achieving a synergistic makeup removal effect, rather than being the dominant factor in the core performance. Test Example 4

[0039] The makeup removal efficiency of the soft wipes prepared in the examples and comparisons, as well as commercially available makeup remover wipes (SANA, Japan), was tested. (1) Makeup removal efficiency test: Each sample was cut into 5cm×5cm size and equilibrated for 24h at 25℃ and 50% relative humidity. The skin on the inner side of the forearm of a healthy adult volunteer after cleaning and drying was selected as the test area. A 2cm×2cm area with a thickness of 0.1mm was evenly applied with a uniform waterproof lipstick using a quantitative applicator. After standing for 8h in the same environment, the K / S value of 3 points in the area after application was tested with a calibrated handheld color tester and the average value was taken. Then, the corresponding sample was wiped 5 times with a force of 5N in the same direction. After the skin was free of residual fibers, the K / S value of the original point after wiping was tested and the average value was taken. The makeup removal rate (%) was calculated according to the formula "(K / S value after application - K / S value after wiping) / K / S value after application × 100%". Each sample was tested in parallel 3 times and the final average value was taken. (2) Immersion water test: Weigh 5g of each sample and put them into clean conical flasks. Add 100mL of deionized water to each conical flask to ensure that the sample is completely submerged in the water. Let it stand and soak for 30min at a constant temperature of 25℃. During this period, gently shake the conical flask once every 10min for 10s each time to ensure that the sample is in full contact with the water. After soaking, use rapid qualitative filter paper to filter the soaking liquid in each conical flask to remove residual fibers and impurities and collect the clear soaking water sample. Use a calibrated precision pH meter (accuracy 0.01) to measure the pH value of each soaking water sample at 25℃. Each sample is measured in parallel 3 times. Before each measurement, rinse the pH meter electrode 3 times with the corresponding soaking water sample. Record the pH value of each measurement and calculate the average value as the final pH value of the soaking water of the sample. Table 2 shows the final measured properties of the cotton towel: Table 2

[0040] As shown in Table 2, the makeup removal rate of the soft wipes in this embodiment reached 93%, slightly higher than that of commercially available makeup remover wipes that rely on chemical solvents. Furthermore, the pH of the soaking water for all three was consistently 7.3, indicating neutrality and compatibility with the skin's physiological environment. This effectively avoids skin irritation or barrier damage that may result from chemical makeup removers. In contrast, commercially available makeup remover wipes contain ethanol, which can damage the skin's surface, and are explicitly labeled as not suitable for contact with eyes. This embodiment, through coaxial spinning combined with a three-stage traction stretching process, successfully constructed a coaxial core-shell structure within functional short fibers. This structure features a synergistic effect between a negatively charged polyelectrolyte-modified nano-zinc oxide shell and a positively charged polyelectrolyte-modified nano-silica core, forming a stable internal potential and nanochannels. This structure can convert ordinary aggregated water into small molecule clusters, efficiently dissolving and removing cosmetics without the need for chemical solvents. Simultaneously, the neutral pH of the soaking water further ensures gentle skincare.

[0041] Comparative Example 1, lacking the addition of positively charged polyelectrolyte-modified nano-silica to the core layer, failed to form an effective built-in potential and complete nanochannels. Comparative Example 2, employing a one-stage traction stretching method, resulted in the destruction of the coaxial core-shell structure and uneven distribution of functional components. Neither could achieve water molecule refinement or efficient makeup removal; they could only rely on physical friction and adsorption to function, thus exhibiting only moderate makeup removal effects. The pH of the soaking water in Comparative Example 1 was 6.8, slightly acidic, while the pH of the soaking water in Comparative Example 2 was 7.3, neutral. This indicates that the synergistic effect of the dual-modified nano-oxides in the core and shell not only affects the makeup removal effect but also has a certain correlation with the pH stability of the soaking water.

[0042] Comparative Example 3, which did not undergo ultrasonic directional activation treatment, had a makeup removal rate of 82%, which was still significantly lower than that of the Example. The pH of the soaking water was 6.8, which was slightly acidic but still mild, confirming that ultrasonic etching only played a synergistic role in makeup removal.

[0043] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for preparing a chemical-free makeup remover wipe, characterized in that, Includes the following steps: S1. Polypolyol, sodium hyaluronate and polystyrene sulfonic acid are dissolved in water to form a gel solution. Nano metal oxides are then added to the gel solution. The mixture is stirred, centrifuged and gelled in sequence to obtain negatively charged polyelectrolyte modified nano metal oxides. S2. Dissolve sodium alginate and polydiallyldimethylammonium chloride in water to form a gel solution. Continue to add mesoporous nano-silica to the gel solution. Perform the first stirring, the first centrifugation, the gelation treatment, the second stirring and the second centrifugation in sequence to obtain positively charged polyelectrolyte modified nano-silica. S3. The shell material is prepared by mixing the negatively charged polyelectrolyte-modified nano-metal oxide and hydrophobic polymer described in S1, and the core material is prepared by mixing the positively charged polyelectrolyte-modified nano-silica and hydrophilic polymer described in S2. The shell material and the core material are coaxially spun, and then subjected to three stages of traction stretching and cutting to obtain functional short fibers. S4. Functional short fibers are prepared into non-woven fabric substrate by hot air bonding method, and then the non-woven fabric substrate is subjected to ultrasonic activation treatment to form a nano-micro rough structure, thus obtaining the chemical-free makeup remover soft towel.

2. The method for preparing the chemical-free makeup remover wipes according to claim 1, characterized in that, In S1, the polyol is selected from one or more of polyvinyl alcohol, polyethylene glycol, and polyglycerol; And / or, the nano-metal oxide is selected from one or more of zinc oxide, titanium oxide, aluminum oxide and zirconium oxide.

3. The method for preparing the chemical-free makeup remover wipes according to claim 1, characterized in that, In S1, the mass ratio of the polyol, sodium hyaluronate, and polystyrene sulfonic acid is 1.0:(0.3-1.0):(2.0-3.5). And / or, the concentration of the gel solution is 20 g / L-50 g / L; And / or, the mass percentage of the nano-metal oxide is 1%-4%.

4. The method for preparing the chemical-free makeup remover wipes according to claim 1, characterized in that, In S1, the temperature of the gelation treatment is 30℃-60℃.

5. The method for preparing the chemical-free makeup remover wipes according to claim 1, characterized in that, In S2, the mass ratio of sodium alginate to polydiallyldimethylammonium chloride is 1:(8-14). And / or, the concentration of the gel solution is 50 g / L-80 g / L; And / or, the mesoporous nano-silica accounts for 1%-4% of the mass.

6. The method for preparing the chemical-free makeup remover wipes according to claim 1, characterized in that, In S2, the gelation treatment uses a calcium chloride solution with a concentration of 9wt%-11wt%.

7. The method for preparing the chemical-free makeup remover wipes according to claim 1, characterized in that, In S3, the hydrophobic polymer is selected from one or more of polyethylene, polypropylene, polylactic acid, and polyamide; And / or, the hydrophilic polymer is a polyhydroxy polyester; And / or, the mass percentage of negatively charged polyelectrolyte-modified nano-metal oxide in the shell material is 4%-6%; And / or, the mass percentage of the core material, positively charged polyelectrolyte-modified nano-silica, is 4%-6%.

8. The method for preparing the chemical-free makeup remover wipes according to claim 1, characterized in that, In S3, the shell temperature of the coaxial spinning is 170℃-190℃, and the core temperature is 195℃-205℃. And / or, the stretching speed of the three-segment traction stretching is 95mpm-105mpm; The initial drawing temperature is 50℃-65℃, and the draw ratio is 1.3-1.6 times; The second drawing temperature is 75℃-85℃, and the draw ratio is 2.1-2.6 times; The three-stage drawing temperature is 41℃-46℃, and the drawing ratio is 1.1-1.3 times.

9. The method for preparing the chemical-free makeup remover wipes according to claim 1, characterized in that, In S4, the process parameters for the hot air bonding method are as follows: hot air temperature is 130℃-210℃, pressure difference is 0.4Pa-2Pa, and production speed is 20m / min-60m / min; And / or, the ultrasonic activation treatment has a frequency of 25kHz-40kHz, a power of 500W-600W, and a duration of 25s-35s.

10. A chemical-free makeup remover wipe prepared by the method according to any one of claims 1-9.

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