Long-acting cool wet tissue compound liquid, wet tissue and preparation method of wet tissue

Abstract

The invention discloses a long-acting cool wet tissue compound liquid, a wet tissue and a preparation method of the wet tissue, and belongs to the technical field of hygienic products. The compound liquid contains three cool feeling agents, namely natural menthol, menthyl lactate and methyl diisopropyl propionamide, and is matched with betaine, a chamomile extracting solution, aloe barbadensis leaf juice, polyethylene glycol and a surfactant to form an alcohol-free formula; the wet tissue adopts an MPM process three-layer composite structure non-woven fabric base material, surface layer polypropylene fibers, middle layer wood pulp fibers and bottom layer polypropylene fibers, and the overall gram weight is 60-80 g / m < 2 >; the preparation method comprises the following steps: preparing a compound solution, infiltrating the base material, cutting and packaging. Through synergistic compounding of the cool feeling agent and slow release design of the base material, instant cooling reaches 5 DEG C, cool feeling lasts for 4 h, stable cool feeling is still kept after water washing, irritation is low, the wet tissue is suitable for sensitive people, meanwhile, the functions of antibiosis, sweat suppression, oil absorption and deodorization are integrated, the problems that an existing cool feeling wet tissue is unbalanced in cool feeling, insufficient in safety and single in function are solved, and the wet tissue is worthy of popularization and application. And the multi-scene use requirements are met.

Description

Technical Field

[0001] This invention relates to the field of hygiene products technology, specifically to a compound liquid for long-lasting cooling wipes that combines instantaneous cooling sensation with long-lasting continuous cooling sensation, high safety and integrated functions, as well as wipes containing the compound liquid and a method for preparing the wipes, suitable for functional cleaning and care needs in different usage scenarios such as infants, people with sensitive skin, and outdoor workers. Background Technology

[0002] With the rapid development of the functional hygiene products market, cooling wipes, as a sub-category, have shown significant growth, with the market size continuing to expand and demand increasing year by year in domestic and overseas markets such as Southeast Asia and Japan. However, the current cooling wipes industry still faces many technical bottlenecks: On the one hand, it is difficult to balance the instantaneous and lasting cooling effect. Traditional single cooling agents such as menthol can provide a short-term and strong cooling sensation, but they are volatile, highly irritating, and the cooling effect is short-lived. Compound cooling agents are mostly simple combinations that fail to create a synergistic effect and cannot meet users' needs for long-lasting cooling. On the other hand, the safety of ingredients is a prominent issue. Some products contain alcohol or irritating ingredients, making them unsuitable for sensitive skin, infants, and other special groups. Furthermore, stricter regulations on the use of ingredients such as menthol in regions such as the EU further limit the application of traditional formulas. In addition, the base material of existing cooling wipes is not compatible with the cooling compound liquid, making it difficult to achieve a slow release of the cooling agent. The cooling effect is easily lost after washing. At the same time, the functions are relatively simple, only meeting basic cooling needs, and lacking the integration of scenario-based functions such as antibacterial, antiperspirant, oil absorption, and deodorization, thus failing to meet diverse consumer needs. Summary of the Invention

[0003] In view of this, the present invention proposes a long-lasting cooling wipe compound liquid, wipes and preparation method thereof, aiming to solve the technical problems of unbalanced cooling effect, insufficient safety, poor substrate compatibility and single function of existing cooling wipes.

[0004] The technical solution of the present invention is implemented as follows: The present invention provides a long-lasting cooling wipe compound liquid, characterized in that it includes the following components: natural menthol, menthyl lactate, methyl diisopropyl propionamide, betaine, chamomile extract, aloe vera leaf juice, polyethylene glycol, and surfactant, and the compound liquid does not contain alcohol, wherein the surfactant is at least one of hydrogenated castor oil and Tween (polyoxyethylene sorbitan fatty acid ester).

[0005] In some implementations, natural menthol serves as the core ingredient for instant cooling, rapidly acting on nerve endings in the skin's surface to achieve an immediate burst of cooling sensation. Menthyl lactate has sustained-release properties, extending the duration of the cooling effect. Methyl diisopropyl propionamide combines high cooling intensity with gentleness. These three components work synergistically to form an "instant-continuous-gentle" cooling system. Hydrogenated castor oil and Tween are both gentle nonionic surfactants that can form stable complexes with lipid-soluble cooling agents, ensuring uniform dispersion in the aqueous compound solution without increasing skin irritation. The compound solution is alcohol-free, avoiding issues such as skin dryness and irritation caused by alcohol, making it suitable for sensitive individuals. While alcohol as a solvent can improve the solubility of some components, it can also damage the lipid structure of the stratum corneum. This invention optimizes component compatibility, achieving stable dispersion of each component in an alcohol-free system while ensuring gentle use.

[0006] In some embodiments, the proportions of each component by weight percentage are as follows: natural menthol 0.3%-0.8%, menthyl lactate 0.5%-1.2%, methyl diisopropyl propionamide 0.2%-0.6%, betaine 1.0%-2.0%, chamomile extract 0.8%-1.5%, aloe vera leaf juice 1.2%-2.5%, polyethylene glycol 2.0%-3.5%, surfactant 1.0%-3.0%, with the balance being deionized water; the compound solution also contains at least one of an antibacterial agent, an antiperspirant, and an oil-absorbing and deodorizing agent.

[0007] In some implementations, this ratio range is determined based on the functional synergy of the ingredients: the proportion of natural menthol is controlled at 0.3%-0.8%, which ensures both the instantaneous cooling intensity and avoids irritation due to excessive concentration; the proportion of menthyl lactate at 0.5%-1.2% can complement the release rate of natural menthol, ensuring a sustained and stable cooling sensation; the addition of methyl diisopropyl propionamide at 0.2%-0.6% can enhance the cooling effect without increasing irritation; while the proportions of betaine, chamomile extract, and aloe vera leaf juice are designed around moisturizing and soothing functions, forming a synergy with the cooling agent and reducing the potential irritation of the cooling ingredients to the skin; the addition of antibacterial agents, antiperspirants, and oil-absorbing and deodorizing agents is based on the need for "multi-purpose towels," and through ingredient compatibility screening, it is ensured that each functional ingredient has no antagonistic effect with the cooling system, achieving functional integration.

[0008] In some embodiments, the weight ratio of the natural menthol, menthyl lactate, and methyl diisopropyl propionamide is (0.3-0.8):(0.5-1.2):(0.2-0.6).

[0009] In some implementations, the core of this weight ratio design lies in achieving a precise balance of cooling effects, and the three cooling agents form a triple synergistic effect of "target complementarity + release synergy + stimulation neutralization", rather than a simple functional superposition: the ratio of natural menthol to menthyl lactate can adjust the intensity ratio of instantaneous cooling and sustained cooling, avoiding problems such as "rapid decay after being too strong" or "long duration but insufficient initial cooling"; the ratio of methyl diisopropyl propionamide neutralizes the irritation of the first two components, while improving the overall cooling intensity. Specifically, natural menthol acts rapidly on the skin's TRPM8 cold receptors, achieving instantaneous cooling within 1 minute; menthyl lactate slowly penetrates through the stratum corneum, continuously activating TRPM8 receptors and prolonging the duration of the cooling sensation; methyl diisopropyl propionamide (WS-23) acts simultaneously on both TRPM8 receptors and skin nerve endings, with a cooling intensity 1.5 times that of natural menthol, and has no penetration-enhancing effect, blocking the penetration of natural menthol into the stratum corneum. The lipid-soluble properties of menthyl lactate further encapsulate natural menthol, reducing irritation. Furthermore, the adsorption capacity of the three cooling agents differs among the intermediate wood pulp fibers (menthyl lactate > natural menthol > WS-23), resulting in a stepwise release curve from rapid release to steady release and then to slow release after compounding, ensuring a continuous and stable cooling sensation.

[0010] In some embodiments, the antibacterial agent is benzalkonium chloride, with a weight percentage of 0.05%-0.1%; the antiperspirant is aluminum hydroxychloride, with a weight percentage of 0.5%-1.0%; and the oil-absorbing and deodorizing agent is modified starch, with a weight percentage of 1.0%-1.8%.

[0011] In some implementations, benzalkonium chloride is chosen as the antibacterial agent because it has broad-spectrum antibacterial properties, low skin irritation at concentrations of 0.05%-0.1%, good compatibility with the cooling system, and does not affect the effectiveness of the cooling agent. Aluminum hydroxychloride is used as an antiperspirant, which can achieve the function of inhibiting sweat by regulating the permeability of sweat gland ducts, and this concentration range will not cause skin dryness or residue. Modified starch achieves the dual functions of oil absorption and deodorization due to its porous structure, and has good biocompatibility, with no interaction with other components in the compound solution, ensuring stable function.

[0012] The compatibility of the aforementioned multifunctional ingredients with cooling and soothing agents has been specifically optimized, solving three major problems commonly encountered in existing technologies: pH fluctuations, ingredient interactions, and functional antagonism. This is achieved by selecting cationic antibacterial agents, nonionic antiperspirants, and neutral oil-absorbing deodorants to avoid the binding of anions and cations; controlling the concentration of each ingredient within the "effective and non-antagonistic" range to avoid high concentrations inhibiting the penetration of cooling agents or the activity of soothing ingredients; and stabilizing the pH of the system at 5.8-6.2 by adjusting the ratio of deionized water to betaine during the preparation of the compound solution, ensuring compatibility with the skin's stratum corneum and guaranteeing ingredient stability.

[0013] In some embodiments, a long-lasting cooling wipe includes the long-lasting cooling wipe compound liquid described in any one of the above embodiments, and a three-layer composite nonwoven fabric substrate using the MPM process; the three-layer composite nonwoven fabric substrate using the MPM process refers to a composite nonwoven fabric with a middle layer of wood pulp fiber and two upper and lower layers of polypropylene (PP) fiber, which achieves tight interlayer bonding through a specific composite process, taking into account both absorbency and durability.

[0014] In some implementations, the three-layer composite structure is designed based on the optimization of cooling agent release and user experience: the top layer of polypropylene fiber has skin-friendly and breathable properties, which can quickly conduct the compound liquid to the skin surface, achieving a rapid onset of instant cooling; the middle layer of wood pulp fiber has high adsorption capacity, which can fully load the cooling agent and functional components in the compound liquid, forming a "storage-slow release" system, extending the duration of cooling and various functions, while retaining some of the loaded components after washing, ensuring residual cooling; the bottom layer of polypropylene fiber has good water-locking and leak-proof properties, preventing the compound liquid from being lost and improving the durability of the wipes. The combination of the three layers achieves the functional synergy of "conduction-storage-locking", solving the problem of poor compatibility of traditional single-substrate materials.

[0015] In some embodiments, the overall basis weight of the three-layer composite nonwoven fabric substrate is 70 g / m². 2 The surface polypropylene fiber has a basis weight of 10-15 g / m². 2 The weight of the intermediate layer wood pulp fiber is 40-50 g / m³. 2 The weight of the bottom polypropylene fiber is 10-15 g / m². 2 The ratio of the three-layer composite nonwoven fabric substrate to the compounded liquid is 1:3.

[0016] In some implementations, the fiber basis weight of each layer is designed to optimize for functional requirements and wood pulp content: overall basis weight 70 g / m². 2 Balancing user comfort with component load, the middle layer contains 40-50g / m² of wood pulp fiber. 2 The weight is sufficient to load a adequate amount of compounded liquid and meet the requirements for long-lasting release; the surface and bottom polypropylene fibers each contain 10-15 g / m². 2 The weight ensures both skin-friendliness and water-locking performance, while avoiding slow penetration of the compound liquid due to excessive weight. The optimized 1:3 liquid-to-material ratio ensures full wetting of the substrate, allowing for sufficient loading of cooling agents and functional ingredients, while preventing liquid residue buildup during use due to excessive compound liquid, thus achieving a balance between user experience and efficacy.

[0017] In some embodiments, the long-lasting cooling wipes are sealed in aluminum foil packaging and stored at an ambient temperature of ≤30°C.

[0018] In some implementations, the aluminum foil sealed packaging is designed to prevent the loss of volatile components (such as natural menthol) in the compound solution, avoid the reduction of cooling effect, and isolate external moisture and bacteria to ensure the safety of the product during storage. The limitation of storage environment temperature ≤30°C is because the cooling agent is easily volatilized at high temperatures, and some functional ingredients (such as chamomile extract and aloe vera leaf juice) may be unstable in high temperature environments. This limitation can ensure that the product maintains its original efficacy and stability during storage.

[0019] In some embodiments, a method for preparing a long-lasting cooling wipe includes the following steps: (1) Preparation of compound solution: Mix the raw materials according to the components and proportions described in any one of the above items to prepare the long-lasting cooling wipe compound solution; (2) Substrate impregnation: The three-layer composite nonwoven fabric is arranged in the impregnation equipment and the compound liquid is sprayed until the substrate is completely penetrated; (3) Cutting and packaging: Cut the soaked substrate to the preset size, seal and package it to obtain the long-lasting cooling wet wipes.

[0020] In some implementations, the design of the preparation method is optimized around the stability of components and the loading effect on the substrate: the order of steps in preparing the compound solution is determined based on the solubility and stability of each component, dissolving water-soluble components first, and then adding fat-soluble components such as cooling agents to avoid component clumping or failure; the substrate impregnation adopts a spray method, which can ensure that the compound solution penetrates evenly to all layers of the three-layer structure, especially the middle layer of wood pulp fiber, to ensure sufficient loading and avoid inconsistent cooling or functional effects caused by uneven local impregnation; the cutting and packaging steps emphasize timely sealing to reduce the loss of volatile components in the compound solution in subsequent processes and ensure the final efficacy of the product.

[0021] In some embodiments, the preparation of the compound solution in step (1) specifically includes: first heating deionized water to 35-40°C, adding polyethylene glycol, betaine and at least one of the antibacterial agent, antiperspirant, and oil-absorbing deodorant, and stirring at 500 r / min for 15 min until the raw materials are completely dissolved; adding natural menthol, menthyl lactate, methyl diisopropyl propionamide and surfactant, and stirring at 800 r / min for 20 min; after mixing, adding chamomile extract, aloe vera leaf juice and fragrance, stirring at low speed for 5 min and letting stand to degas for 10 min.

[0022] In some embodiments, the parameters of this specific preparation process are designed with clear specificity: a heating temperature of 35-40℃ can both increase the dissolution rate of components such as polyethylene glycol and betaine and avoid the deterioration of components caused by high temperature; a stirring speed of 500r / min and a stirring time of 15min ensure that water-soluble components are fully dissolved and evenly dispersed; the addition of cooling agents is because cooling agents such as natural menthol are volatile, and a low temperature environment can reduce their evaporation loss, while a high stirring speed of 800r / min can ensure that fat-soluble cooling agents are evenly dispersed in the aqueous system and avoid agglomeration; finally, low-speed stirring and standing to degas are to remove air bubbles in the compound solution, avoid uneven wetting caused by air bubbles during subsequent substrate wetting, and at the same time ensure that the wet wipes have a smooth feel when used.

[0023] In some embodiments, the weight ratio of betaine, chamomile extract, and aloe vera leaf juice is (1.0-2.0):(0.8-1.5):(1.2-2.5).

[0024] In some implementations, this weight ratio is designed to optimize the synergistic effects of moisturizing and soothing: betaine, as a moisturizer, can quickly replenish and lock in skin moisture, building a moisturizing barrier for the skin; chamomile extract focuses on soothing and calming, reducing the potential irritation of the cooling agent to the skin; and aloe vera leaf juice has both moisturizing and repairing functions. The ratio of the three components is carefully selected to ensure synergy in moisturizing, soothing, and repairing, which not only improves the skin's tolerance to the cooling ingredients but also avoids skin discomfort caused by excessive amounts of a single ingredient. This complements the cooling system and further enhances the user experience of the product.

[0025] The present invention has the following advantages over the prior art: This invention solves the problem of existing cooling wipes' inability to simultaneously achieve instant cooling and long-lasting effects through a precise blend of three cooling agents: natural menthol, menthyl lactate, and methyl diisopropyl propionamide, designed in specific proportions. Furthermore, the addition of moisturizing and soothing ingredients such as betaine and chamomile extract, along with an alcohol-free formula, significantly reduces product irritation, making it suitable for sensitive skin, infants, and other special populations, thus overcoming the safety deficiencies of existing products. The MPM process, with its three-layer composite non-woven fabric substrate, optimizes the release characteristics of the cooling agents, achieving a slow release of the cooling agents. The residual cooling sensation after washing improves the compatibility between the substrate and the compounding solution, overcoming the problem of poor cooling retention of traditional substrates. Furthermore, by integrating antibacterial, antiperspirant, oil-absorbing, and deodorizing functional ingredients, this invention achieves multiple uses for a single wipe, meeting diverse scenario-based needs and changing the current situation of single-function cooling wipes. Simultaneously, targeted manufacturing processes and packaging and storage designs ensure the stability and consistency of product efficacy. The overall technical solution forms a functionally synergistic, safe, and reliable long-lasting cooling wipe system, effectively solving many pain points of existing technologies. Detailed Implementation

[0026] 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 a part of the embodiments of the present invention, and not all of the 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.

[0027] Example 1 1. Preparation of the compound solution: Deionized water was used as the remaining solvent and heated to 35°C. 2.0% polyethylene glycol, 1.0% betaine, and 0.05% benzalkonium chloride (antibacterial agent) were added and stirred at 500 r / min for 15 min until all raw materials were completely dissolved. 0.3% natural menthol, 0.5% menthyl lactate, 0.2% methyl diisopropyl propionamide, and 1.0% hydrogenated castor oil were added and stirred at 800 r / min for 20 min to ensure uniform dispersion of the cooling agent. Finally, 0.8% chamomile extract, 1.2% aloe vera leaf juice, and 0.03% fragrance were added and stirred at 300 r / min for 5 min. The mixture was allowed to stand for 10 min to remove bubbles, thus obtaining the long-lasting cooling wipe compound solution.

[0028] 2. Substrate impregnation: A three-layer composite nonwoven fabric substrate using the MPM process is selected, with an overall basis weight of 70 g / m². 2 The surface layer has a concentration of 10g / m³. 2 Polypropylene fiber, with an intermediate layer of 40g / m 2 Wood pulp fiber, bottom layer is 10g / m 2 Polypropylene fibers; place the substrate in an impregnation device, and spray the prepared compound solution evenly at a liquid-to-solid ratio of 1:3 (weight of nonwoven fabric: weight of compound solution), and impregnate for 30 seconds until the substrate is completely penetrated.

[0029] 3. Cutting and Packaging: Cut the soaked substrate into a preset size of 20cm×15cm, seal it with aluminum foil, and you will get the long-lasting cooling wipes. The finished product should be stored in a cool and dry environment with a temperature of ≤30℃.

[0030] Example 2 1. Preparation of the compound solution: Using deionized water as the remaining solvent, heat it to 38℃, add 2.8% polyethylene glycol, 1.5% betaine, 0.08% benzalkonium chloride (antibacterial agent), 0.7% aluminum hydroxychloride (antiperspirant), and 1.4% modified starch (oil absorbent and deodorant). Stir at 500 rpm for 15 min until all raw materials are completely dissolved. Add 0.5% natural menthol, 0.8% menthyl lactate, 0.4% methyl diisopropyl propionamide, and 2.0% Tween-80. Stir at 800 rpm for 20 min to ensure uniform dispersion of the cooling agent. Finally, add 1.2% chamomile extract, 1.8% aloe vera leaf juice, and 0.05% fragrance. Stir at 300 rpm for 5 min and let stand for 10 min to remove bubbles to obtain the long-lasting cooling wipe compound solution.

[0031] 2. Substrate impregnation: A three-layer composite nonwoven fabric substrate using the MPM process is selected, with an overall basis weight of 70 g / m². 2 The surface layer has a concentration of 14 g / m³. 2 The polypropylene fiber and the intermediate layer are 45g / m 2 Wood pulp fiber, bottom layer 14g / m 2 Polypropylene fibers; place the substrate in an impregnation device, spray the above compounded solution evenly at a liquid-to-solid ratio of 1:3, and impregnate for 30 seconds until the substrate is completely penetrated.

[0032] 3. Cutting and Packaging: Cut the impregnated substrate into 20cm×15cm sizes, seal it with aluminum foil, and store the finished product in an environment with a temperature ≤30℃.

[0033] Example 3 1. Preparation of the compound solution: Using deionized water as the remaining solvent, heat it to 40℃, add 3.5% polyethylene glycol, 2.0% betaine, 0.1% benzalkonium chloride (antibacterial agent), 1.0% aluminum hydroxychloride (antiperspirant), and 1.8% modified starch (oil absorbent and deodorant). Stir at 500 rpm for 15 min until all raw materials are completely dissolved. Add 0.8% natural menthol, 1.2% menthyl lactate, 0.6% methyl diisopropyl propionamide, 1.5% hydrogenated castor oil, and 1.5% Tween-60. Stir at 800 rpm for 20 min to ensure uniform dispersion of the cooling agent. Finally, add 1.5% chamomile extract, 2.5% aloe vera leaf juice, and 0.08% fragrance. Stir at 300 rpm for 5 min and let stand for 10 min to remove bubbles to obtain the long-lasting cooling wipe compound solution.

[0034] 2. Substrate impregnation: A three-layer composite nonwoven fabric substrate using the MPM process is selected, with an overall basis weight of 80 g / m². 2 The surface layer has a concentration of 15g / m³. 2 Polypropylene fiber, with an intermediate layer of 50g / m2 Wood pulp fiber, bottom layer is 15g / m 2 Polypropylene fibers; place the substrate in an impregnation device, spray the above compounded solution evenly at a liquid-to-solid ratio of 1:3, and impregnate for 30 seconds until the substrate is completely penetrated.

[0035] 3. Cutting and Packaging: Cut the impregnated substrate into 20cm×15cm sizes, seal it with aluminum foil, and store the finished product in an environment with a temperature ≤30℃.

[0036] Comparative Example 1 1. Preparation of the compound solution: Except for the cooling agent which contains only 0.5% natural menthol and 0.8% menthyl lactate (methyl diisopropyl propionamide is removed), the remaining components (polyethylene glycol 2.8%, betaine 1.5%, benzalkonium chloride 0.08%, aluminum hydroxychloride 0.7%, modified starch 1.4%, chamomile extract 1.2%, aloe vera leaf juice 1.8%, fragrance 0.05%, Tween-80 2.0%, with the balance being deionized water), the order of addition, and the stirring parameters (temperature, speed, and time) are completely consistent with those in Example 2, and the compound solution is prepared.

[0037] 2. Substrate impregnation: The same MPM process was used as in Example 2 for the three-layer composite nonwoven fabric substrate and the liquid-to-material ratio was 1:3. The substrate was impregnated for 30 seconds until it was completely penetrated.

[0038] 3. Cutting and Packaging: The cutting dimensions, aluminum foil sealing packaging method, and storage conditions are the same as in Example 2.

[0039] Comparative Example 2 1. Preparation of compound solution: The compound solution was prepared in accordance with the same composition, preparation steps and stirring parameters as in Example 2.

[0040] 2. Substrate impregnation: Select a substrate weight of 45 g / m². 2 Using conventional spunlace nonwoven fabric (without a three-layer composite structure) as the substrate, the compound solution is sprayed evenly at a liquid-to-material ratio of 1:3 and soaked for 30 seconds until the substrate is completely penetrated.

[0041] 3. Cutting and Packaging: The cutting dimensions, aluminum foil sealing packaging method, and storage conditions are the same as in Example 2.

[0042] Comparative Example 3 1. Preparation of compound solution: The cooling agent contains only 1.7% natural menthol (the total content is the same as the sum of the three cooling agents in Example 2). 5% alcohol is added as a solvent. The remaining functional components (0.08% benzalkonium chloride, 0.7% aluminum hydroxychloride, and 1.4% modified starch) and preparation steps and stirring parameters are the same as in Example 2. Polyethylene glycol, betaine, chamomile extract, and aloe vera leaf juice are removed to prepare the compound solution.

[0043] 2. Substrate impregnation: Select a substrate weight of 45 g / m². 2 Using conventional spunlace nonwoven fabric as the substrate, the compound solution is sprayed evenly at a liquid-to-material ratio of 1:3 and soaked for 30 seconds until the substrate is completely penetrated.

[0044] 3. Cutting and Packaging: The cutting dimensions, aluminum foil sealing packaging method, and storage conditions are the same as in Example 2.

[0045] Comparative Example 4 1. Preparation of compound solution: The compound solution was prepared in accordance with the same composition, preparation steps and stirring parameters as in Example 2.

[0046] 2. Substrate impregnation: Select a two-layer composite nonwoven fabric substrate (surface layer 34g / m²). 2 Polypropylene fiber, bottom layer 39g / m 2 Polypropylene fibers, total weight 73g / m 2 Remove the middle layer of wood pulp fiber), spray the compound solution evenly at a liquid-to-material ratio of 1:3, and soak for 30 seconds until the substrate is completely penetrated.

[0047] 3. Cutting and Packaging: The cutting dimensions, aluminum foil sealing packaging method, and storage conditions are the same as in Example 2.

[0048] Comparative Example 5 1. Preparation of compound solution: The proportion of cooling agent was adjusted to 1.0% natural menthol, 0.3% menthyl lactate, and 0.1% methyl diisopropyl propionamide (exceeding the proportion range defined in claim 3). The remaining components, addition order, and stirring parameters were completely consistent with those in Example 2, and the compound solution was prepared.

[0049] 2. Substrate impregnation: The same MPM process was used as in Example 2 for the three-layer composite nonwoven fabric substrate and the liquid-to-material ratio was 1:3. The substrate was impregnated for 30 seconds until it was completely penetrated.

[0050] 3. Cutting and Packaging: The cutting dimensions, aluminum foil sealing packaging method, and storage conditions are the same as in Example 2.

[0051] Comparative Example 6 We directly purchased the top 3 best-selling cooling and antibacterial wipes on the market (labeled with "long-lasting" function). Their ingredients include alcohol and a single menthol cooling agent. The base material is conventional spunlace nonwoven fabric. They were stored under the normal conditions indicated on the product label and used directly for performance testing.

[0052] Performance verification 1. Instantaneous cooling rate test Referring to the relevant temperature testing methods in the GB / T38722-2020 standard "Wet Wipes", 30 healthy volunteers (aged 18-45, half male and half female, with no history of skin diseases or allergies) were selected. Before the test, the volunteers sat quietly for 30 minutes in a constant temperature and humidity environment of 25℃ and 50% humidity. The initial skin temperature (T0) of the inner forearm (test area 5cm×5cm) was measured using a skin thermometer with an accuracy of ±0.1℃. Then, each test sample (Examples 1-3, Comparative Examples 1-6) was applied to the test area, and the skin temperature of the area was measured immediately after 1 minute (T1). The difference between T0 and T1 was calculated as the instantaneous cooling amplitude, and the average value of the test results of the 30 volunteers was taken as the final data.

[0053] 2. Duration of cooling sensation test Sensory evaluation was used, with the same 30 volunteers and testing environment as the instantaneous cooling amplitude test. Volunteers applied each test sample to the inner forearm for 1 minute, and then continuously evaluated the intensity of the cooling sensation using a 10-point scale (1 point = no cooling sensation, 10 points = extremely strong cooling sensation). Scores were recorded every 15 minutes; when the score dropped to 3 points or below, timing was stopped, and this time period was considered the duration of the cooling sensation. The average of the results from the 30 volunteers was taken as the final data.

[0054] 3. Test on residual cooling sensation after washing Each test sample was cut into 5cm×5cm pieces and rinsed three times in clean water (25℃), each rinse lasting 30 seconds (using gentle rubbing to simulate a washing scenario after actual use). After rinsing, the sample surface moisture was dried with clean filter paper, and the cooling intensity was immediately tested (the test method was consistent with the sensory evaluation in the cooling duration test). The cooling intensity after washing was recorded as S1. At the same time, the initial cooling intensity of the unwashed samples from the same batch was tested (recorded as S0). The cooling residual rate was calculated using the formula "Cooling residual rate = (S1 / S0) × 100%", and the average value of the three parallel sample test results was taken as the final data.

[0055] 4. Skin irritation test According to ISO 10993-10 "Biological evaluation of medical devices - Part 10: Skin irritation and sensitization tests", six healthy guinea pigs (weighing 250-300g, half male and half female) were selected. Each test sample was cut to a size of 2cm × 2cm, removed from its packaging, and directly applied to the hair-removed area on the guinea pig's back (hair removal area 5cm × 5cm; no skin abnormalities were observed for 24 hours after hair removal). The sample was secured with medical tape and removed after 24 hours. Skin reactions were observed at 1 hour, 24 hours, and 48 hours after sample removal. A standard scoring scale was used (0 = no reaction, 1 = mild erythema, 2 = significant erythema + mild edema, 3 = severe erythema + moderate edema, 4 = severe erythema + severe edema + erosion). The average score of the six guinea pigs was taken as the final data.

[0056] 5. Antibacterial rate test According to the antibacterial test method in GB15979-2002 "Hygienic Standard for Disposable Sanitary Products", *Escherichia coli* (ATCC25922) and *Staphylococcus aureus* (ATCC6538) were selected as test strains. Each test sample was cut into 1cm × 1cm pieces and placed in a bacterial solution (concentration 1 × 10⁻⁶). 6 The samples were cultured in petri dishes containing CFU / mL at 37℃ for 24 hours. A blank control group (containing bacterial culture without samples) was set up at the same time. After the culture was completed, the number of colonies was counted by plate counting method. The antibacterial rate was calculated according to the formula "antibacterial rate = (number of colonies in blank control group - number of colonies in sample group) / number of colonies in blank control group × 100%". The average value of the three parallel test results was taken as the final data.

[0057] 6. Sweat suppression rate test Thirty healthy volunteers (aged 18-45, half male and half female, with normal axillary sweating) were selected and sat quietly for 30 minutes in an environment of 30℃ and 60% humidity. Sterile absorbent cotton was weighed and applied to the volunteers' armpits, fixed for 30 minutes, then removed, weighed, and the initial sweat secretion was recorded (blank group). The next day at the same time, each test sample (cut to 5cm×5cm) was applied to the volunteers' armpits for 1 minute. After removing the sample, sterile absorbent cotton was placed in the same manner, and after 30 minutes, it was removed, weighed, and the sweat secretion after using the sample was recorded (experimental group). The sweat suppression rate was calculated using the formula "sweat suppression rate = (sweat secretion in the blank group - sweat secretion in the experimental group) / sweat secretion in the blank group × 100%", and the average of the test results of the 30 volunteers was taken as the final data.

[0058] 7. Oil absorption rate test Cut each test sample into 2cm×2cm sizes and weigh them (recorded as m0). Immerse the sample completely in liquid paraffin, let it stand for 30 minutes, then remove it, blot off the excess liquid paraffin on the surface with filter paper, and weigh it again (recorded as m1). Calculate the oil absorption rate using the formula "oil absorption rate = (m1-m0) / m0×100%", and take the average of the test results of 3 sets of parallel samples as the final data.

[0059] 8. Skin moisture loss rate (TEWL) test A skin moisture loss tester was used, with the same 30 volunteers and testing environment as the instantaneous cooling amplitude test. Before the test, the initial moisture loss (M0) of the test area on the inner forearm of each volunteer was measured. Each test sample was applied to the test area for 1 minute, removed, and left to stand for 2 hours. The moisture loss in that area was measured again (M1). The skin moisture loss rate was calculated using the formula "Skin moisture loss rate = (M1 - M0) / M0 × 100%", and the average of the results from the 30 volunteers was taken as the final data.

[0060] Performance verification data results

[0061] Examples 1-3, through a specific ratio of natural menthol, menthyl lactate, and methyl diisopropyl propionamide, combined with a three-layer composite nonwoven fabric substrate using MPM technology and an alcohol-free soothing formula, achieved a synergistic effect of instantaneous cooling and long-lasting cooling, while maintaining a stable cooling residue after washing. It also possesses integrated functions such as low irritation, antibacterial, antiperspirant, and oil absorption, adapting to the needs of different people and scenarios. Comparative experiments showed that Comparative Example 1, lacking methyl diisopropyl propionamide, had a significantly reduced duration of cooling and mildness; Comparative Example 2, using conventional spunlace nonwoven fabric, had a cooling residue rate of less than 30% after washing; Comparative Example 3, containing alcohol and a single cooling agent, had a skin irritation score of 3.0 and a significantly increased moisture loss rate; Comparative Example 4, lacking the middle layer of wood pulp fiber, showed a deteriorated cooling effect; Comparative Example 5, with an unbalanced ratio of cooling agents, showed an imbalance between cooling intensity and mildness; and Comparative Example 6, a commercially available product, was comprehensively inferior to this invention in terms of cooling durability, multifunctional integration, and safety. The above comparison confirms that the cooling agent compound system, the three-layer composite substrate design, and the process parameter optimization of the present invention form a synergistic effect, effectively solving the core pain points of the prior art. The technical solution is stable, feasible, and has significant advantages.

[0062] To verify the synergistic effect of the three cooling agents, release rate tests and stimulus neutralization effect tests were conducted. The experimental data are shown in the table below:

[0063] Note: The specific test methods are as follows: 1. Cooling agent release rate (HPLC method): A C18 column (4.6 mm × 250 mm, 5 μm) was used. The mobile phase was methanol-acetonitrile-0.01 mol / L potassium dihydrogen phosphate buffer (50:30:20, v / v / v). The column temperature was 30℃, the detection wavelength was 210 nm, the flow rate was 1.0 mL / min, and simulated skin sweat buffer (pH=5.5) was used as the receiving medium. Diffusion was performed at 32℃. 2. Irritation-related indicators (in vitro skin model method): EpiDerm was used. TM The model (EPI-200) was incubated at 37℃ and 5% CO2 for 24 hours, and the transepidermal water loss (TEWL value) and the secretion of the inflammatory factor IL-1α were measured.

[0064] Experimental data showed that the cumulative release rate at 1 minute after the three cooling agents were combined (35.2%) was significantly lower than that of natural menthol alone (68.5%), avoiding the skin irritation caused by a sudden increase in cooling intensity. This aligns with the complementary target design of "rapid onset of natural menthol + smooth transition of WS-23". The cumulative release rate at 4 hours (92.3%) was higher than that of the combination of the three agents (85.7%) and single application (41.2%), achieving a long-lasting cooling effect and confirming the synergistic effect of "stepwise release". Simultaneously, the in vitro skin TEWL value (8.2 g / h) was significantly lower. m 2 The secretion levels of the inflammatory factor IL-1α (12.8 pg / mL) were significantly lower than those of the two combined (12.5 g / mL). m 2 25.3 pg / mL) and menthol alone (18.6 g / h) m 2 (48.5 pg / mL), demonstrating that the irritant effect of natural menthol was effectively neutralized by WS-23 and menthyl lactate, exhibiting a significant triple synergistic effect. The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A long-lasting cooling wipe compound solution, characterized in that, It includes the following ingredients: natural menthol, menthyl lactate, methyl diisopropyl propionamide, betaine, chamomile extract, aloe vera leaf juice, polyethylene glycol, and surfactant, and the compound solution does not contain alcohol. The surfactant is at least one of hydrogenated castor oil and Tween.

2. The long-lasting cooling wipe compound solution according to claim 1, characterized in that, The percentage of each ingredient by weight is as follows: natural menthol 0.3%-0.8%, menthyl lactate 0.5%-1.2%, methyl diisopropyl propionamide 0.2%-0.6%, betaine 1.0%-2.0%, chamomile extract 0.8%-1.5%, aloe vera leaf juice 1.2%-2.5%, polyethylene glycol 2.0%-3.5%, surfactant 1.0%-3.0%, with the balance being deionized water; the compound solution also contains at least one of an antibacterial agent, an antiperspirant, and an oil-absorbing and deodorizing agent.

3. The long-lasting cooling wipes compound solution according to claim 2, characterized in that, The weight ratio of natural menthol, menthyl lactate, and methyl diisopropyl propionamide is (0.3-0.8):(0.5-1.2):(0.2-0.6).

4. The long-lasting cooling wipes compound solution according to claim 2, characterized in that, The antibacterial agent is benzalkonium chloride, with a weight percentage of 0.05%-0.1%; the antiperspirant is aluminum hydroxychloride, with a weight percentage of 0.5%-1.0%; and the oil-absorbing and deodorizing agent is modified starch, with a weight percentage of 1.0%-1.8%.

5. A long-lasting cooling wet wipe, characterized in that, The invention includes the long-lasting cooling wipe compound liquid as described in any one of claims 1-4, and the MPM process three-layer composite structure nonwoven fabric substrate; the three-layer composite structure nonwoven fabric substrate is composed of a surface layer of polypropylene fiber, a middle layer of wood pulp fiber, and a bottom layer of polypropylene fiber.

6. The long-lasting cooling wipes according to claim 5, characterized in that, The overall basis weight of the three-layer composite nonwoven fabric substrate is 60-80 g / m². 2 The surface polypropylene fiber has a basis weight of 10-15 g / m². 2 The weight of the intermediate layer wood pulp fiber is 40-50 g / m³. 2 The weight of the bottom polypropylene fiber is 10-15 g / m². 2 The ratio of the three-layer composite nonwoven fabric substrate to the compounded liquid is 1:

3.

7. The long-lasting cooling wipes according to claim 5, characterized in that, The long-lasting cooling wipes are sealed in aluminum foil packaging and stored at an ambient temperature of ≤30℃.

8. A method for preparing a long-lasting cooling wet wipe, characterized in that, Includes the following steps: (1) Preparation of compound solution: Mix the raw materials according to the components and proportions described in any one of claims 1-4 to prepare a long-lasting cooling wet wipe compound solution; (2) Substrate impregnation: The MPM process three-layer composite nonwoven fabric is arranged in the impregnation equipment and the compound solution is sprayed until the substrate is completely penetrated; (3) Cutting and packaging: Cut the soaked substrate to the preset size, seal and package it to obtain the long-lasting cooling wet wipes.

9. The preparation method according to claim 8, characterized in that, The preparation of the compound solution in step (1) specifically includes: first heating deionized water to 35-40℃, adding polyethylene glycol, betaine and at least one of the antibacterial agent, antiperspirant, and oil-absorbing deodorant, and stirring at 500r / min for 15min until the raw materials are completely dissolved; adding natural menthol, menthyl lactate, methyl diisopropyl propionamide and surfactant, and stirring at 800r / min for 20min; after mixing, adding chamomile extract, aloe vera leaf juice and fragrance, stirring at low speed for 5min and letting stand to degas for 10min.

10. The long-lasting cooling wipes compound solution according to claim 2, characterized in that, The weight ratio of betaine, chamomile extract, and aloe vera leaf juice is (1.0-2.0):(0.8-1.5):(1.2-2.5).

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