A hand sanitizer for pigment residues and a preparation method thereof

Abstract

The application discloses a hand sanitizer for pigment residues and a preparation method thereof and belongs to the technical field of daily cleaning supplies. The hand sanitizer contains 12-18% of a composite surfactant, 3-6% of a pigment stripping composite agent, 0.5-2% of flexible friction microspheres and auxiliary materials and deionized water in percentage by mass. The composite surfactant is compounded by sodium lauroyl glutamate, cocamide propyl betaine and decyl glucoside in a mass ratio of (3-5):(2-3):1. The pigment stripping composite agent is compounded by hydroxypropyl-beta-cyclodextrin, sodium polyglutamate and sodium lauroyl lactylate in a mass ratio of (2-3.5):1:(1-2). The application can effectively remove various types of hand pigment residues through the synergistic effect of multiple components, has good skin mildness and moisturizing effect after washing, has simple preparation technology, has good system stability and is suitable for industrial production.

Description

Technical Field

[0001] This invention belongs to the technical field of daily cleaning products, specifically relating to a hand sanitizer for use with pigment residue and its preparation method. Background Technology

[0002] With the rapid development of art education, the makeup industry, and the handicraft and cultural creative fields, more and more people are frequently in contact with various pigments in their work and life. Common pigments are mostly composed of colored powders and film-forming matrices: inorganic pigments such as titanium dioxide and iron oxide pigments have small particles that are easily adsorbed onto the skin surface due to static electricity and van der Waals forces, embedding themselves deep in fingerprints and palm lines; organic synthetic pigments and film-forming pigments such as acrylic paints and oil paints contain acrylic resins, drying oils, waxes, and other binding film components, which form a dense film after drying, with strong adhesion to the skin, making them difficult to remove completely by conventional cleaning methods.

[0003] Currently available hand sanitizers are primarily designed for everyday oil and dust stains, and their cleaning efficiency for stubborn pigment residues is generally insufficient, often requiring repeated rinsing and still leaving pigment stains. Existing cleaning products for stubborn stains mainly suffer from two types of technical deficiencies: Firstly, solvent-based cleaning products rely on strong organic solvents such as acetone, ethyl acetate, and isopropanol to dissolve pigment film-forming components. Although they clean quickly, the strong degreasing power of organic solvents can damage the lipid barrier of the stratum corneum of the skin. Long-term use can easily cause dry, flaky, red, and itchy hands, and may even induce contact dermatitis, posing significant skin safety risks. Secondly, high-degreasing cleaning products enhance their cleaning power by increasing the content of strong anionic surfactants such as sodium lauryl sulfate and sodium lauryl ether sulfate. These products have a high pH and excessive degreasing power, which can wash away the skin's natural sebum, resulting in tight and dry hands after washing. Long-term use can also damage the skin barrier and increase the risk of skin sensitivity.

[0004] In addition, existing cleaning products are not designed with a dedicated cleaning system for the mechanism of action of pigment residues, and cannot simultaneously solve multiple problems such as electrostatic adsorption of inorganic pigments, hydrophobic and insoluble organic pigments, and tight adhesion of film-forming pigments. They have shortcomings such as single cleaning target, weak synergistic effect, and low cleaning efficiency.

[0005] Therefore, developing a specialized hand sanitizer that can effectively remove various pigment residues while also being gentle on the skin and repairing the skin barrier is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a hand sanitizer for removing pigment residues and its preparation method. This invention achieves efficient removal of inorganic, organic, and film-forming pigments by constructing a synergistic cleaning system, while maintaining excellent skin compatibility and providing moisturizing and repairing effects after washing. This overcomes the technical defects of existing pigment cleaning products, such as insufficient cleaning power, strong irritation, and dryness and tightness after washing.

[0007] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: This invention provides a hand sanitizer for use with pigment residue, comprising, by weight percentage: 12-18% composite surfactant, 3-6% pigment stripping composite agent, and 0.5-2% flexible friction microspheres; the hand sanitizer also contains excipients and solvents.

[0008] Furthermore, the composite surfactant is composed of sodium lauroyl glutamate, cocamidopropyl betaine, and decyl glucoside in a mass ratio of (3-5):(2-3):1.

[0009] Sodium lauroyl glutamate is an amino acid-based anionic surfactant that produces fine, dense foam with gentle cleaning power and extremely low skin irritation. Cocamidopropyl betaine is an amphoteric surfactant that enhances the foaming performance and hard water resistance of the system while further reducing overall irritation. Decyl glucoside is a nonionic surfactant with excellent wetting and penetrating properties, allowing it to quickly penetrate skin texture and pigment adhesion interfaces, reducing the binding force between pigments and skin. The three surfactants are blended in a specific ratio to achieve excellent cleaning power and foaming performance at a relatively low total active ingredient content, while ensuring the system's gentleness.

[0010] Furthermore, the pigment stripping compound is composed of hydroxypropyl-β-cyclodextrin, sodium polyglutamate, and sodium lauroyl lactylate in a mass ratio of (2-3.5):1:(1-2).

[0011] Hydroxypropyl-β-cyclodextrin, with its hydrophobic inner cavity and hydrophilic outer shell, can encapsulate hydrophobic organic pigment molecules and film-forming resin components through host-guest inclusion, thereby reducing the adhesion of hydrophobic substances to the skin surface. Sodium polyglutamate carries a large number of negative charges, which can disperse inorganic pigment particles through electrostatic repulsion, preventing particle aggregation and redeposition after washing, while also providing long-lasting moisturizing effects. Sodium lauroyl lactylate, an anionic surfactant with both hydrophilic and lipophilic groups, has the ability to reduce interfacial tension. This component can promote the spread of the cleansing system and influence the interfacial properties between pigment particles and the stratum corneum through penetration, helping to weaken interfacial binding. These three components work from three dimensions—organic pigment inclusion, inorganic pigment dispersion, and interfacial regulation—forming a synergistic cleansing system that improves the removal efficiency of various pigments.

[0012] Preferably, the hand sanitizer contains the following components by mass percentage: 13.5-16.5% compound surfactant, 4-5.5% pigment stripping compound, and 1-1.5% flexible tribospheres.

[0013] Furthermore, the composite surfactant is composed of sodium lauroyl glutamate, cocamidopropyl betaine, and decyl glucoside in a mass ratio of (3.5-4.5):(2.25-2.75):1.

[0014] Furthermore, the pigment stripping compound is composed of hydroxypropyl-β-cyclodextrin, sodium polyglutamate, and sodium lauroyl lactylate in a mass ratio of (2.5-3.33):1:(1.47-1.77).

[0015] Preferably, the flexible triboelectric microspheres are polylactic acid microspheres with a particle size of 10-50 μm. Polylactic acid is a biodegradable polymer material with excellent biocompatibility. The microspheres are flexible and can gently remove pigment particles embedded deep in the skin texture through gentle physical friction during rubbing and washing without abrading the stratum corneum or causing mechanical irritation.

[0016] Preferably, the excipients include skin conditioning agents, antibacterial agents, and pH adjusters.

[0017] Preferably, the solvent is deionized water.

[0018] Furthermore, the antibacterial agent is a compound of 1,2-hexanediol and p-hydroxyacetophenone in a mass ratio of 2:1.

[0019] Furthermore, the skin conditioning agent includes ceramide NP, phytosterols, and oat beta-glucan. Ceramides and phytosterols are inherent lipid components of the skin barrier, which can replenish the stratum corneum lipids slightly lost during cleansing and maintain the integrity of the skin barrier; oat beta-glucan can form a breathable moisturizing film on the skin surface, relieving the tightness after washing, while also having a certain soothing and repairing effect, reducing the potential irritation to the skin during the cleansing process.

[0020] The present invention also provides a method for preparing the above-mentioned hand sanitizer for pigment residue, comprising the following steps: Step 1: Add the amount of deionized water specified in the formula to a container, add oat β-glucan at 200-300 rpm, stir until completely dissolved, and heat to 45-50℃; Step 2: Add the components of the composite surfactant and pigment stripping composite agent in the prescribed amounts in sequence, and stir at a constant speed for 20-30 minutes; Step 3: Add the formulated amount of flexible friction microspheres, stir at 800-1200 rpm for 10-15 min, turn on the cooling water to cool down, and when the system temperature drops to 35-40℃, add the formulated amount of ceramide NP, phytosterol and antibacterial agent, stir evenly, adjust the pH value, filter and discharge to obtain the hand sanitizer.

[0021] The beneficial effects of this invention are: 1. This invention utilizes the synergistic effect of composite surfactants, pigment stripping composites, and flexible friction microspheres to work through multiple pathways, including emulsification and decontamination, molecular encapsulation, electrostatic dispersion of particles, interfacial penetration, and physical-assisted friction. It has a good removal effect on hand residues with different adhesion mechanisms, such as acrylic paint, watercolor paint, and cosmetic paint, and its cleaning performance is superior to that of ordinary daily hand sanitizers.

[0022] 2. The formulation of this invention does not use strong organic solvents or strong degreasing surfactants. Instead, it employs a mild compound system of amino acid surfactants, amphoteric surfactants, and nonionic surfactants, combined with flexible polylactic acid microspheres. Tests have shown that it has low skin irritation and can reduce the risk of skin damage during the cleansing process.

[0023] 3. The formula of this invention contains skin conditioning ingredients such as ceramide NP, phytosterols and oat β-glucan, which, together with the moisturizing and water-locking effect of sodium polyglutamate, result in good skin moisture retention after washing and minimal changes in transepidermal water loss. This helps maintain the basic state of the skin barrier and relieves the tightness that often occurs after washing with conventional cleansing products. Detailed Implementation

[0024] To further illustrate the present invention, detailed descriptions are provided below through the following embodiments. The raw materials used in the following embodiments and comparative examples of the present invention are all commercially available products; the raw material companies listed below represent one of the ways to purchase the raw materials.

[0025] I. Raw Material Description Sodium lauroyl glutamate: purchased from Guangzhou Huayu Fine Chemical Co., Ltd.; Cocamidopropyl betaine: purchased from Guangzhou Huayu Fine Chemical Co., Ltd.; Decyl glucoside: purchased from Shanghai Fakai Chemical Co., Ltd.; Sodium lauroyl lactyl lactate: purchased from Hubei Qifei Pharmaceutical Chemical Co., Ltd.; Hydroxypropyl-β-cyclodextrin: purchased from Shandong Binzhou Zhiyuan Biotechnology Co., Ltd.; Sodium polyglutamate: purchased from Shandong Freda Biotechnology Co., Ltd.; Polylactic acid microspheres: particle size 20-30μm, purchased from Shenzhen Jusheng Biotechnology Co., Ltd.; All other raw materials are commercially available.

[0026] II. Examples 1-5 The hand sanitizer for pigment residue of the present invention was prepared according to the raw material mass percentages shown in Table 1. A total of 5 examples were set up, and the preparation methods of each example are as follows: Step 1: Add the amount of deionized water specified in the formula to the mixing tank, turn on the stirrer, add oat β-glucan at 28℃ and 250 rpm, stir until completely dissolved, and then heat to 48℃. Step 2: Add sodium lauroyl glutamate, cocamidopropyl betaine, decyl glucoside, hydroxypropyl-β-cyclodextrin, sodium polyglutamate, and sodium lauroyl lactylate in sequence, and stir at 250 rpm for 25 minutes. Step 3: Add polylactic acid microspheres, increase the speed to 1000 rpm and stir until evenly dispersed. Turn on the cooling water to cool down. When the temperature drops to 38°C, add ceramide NP, phytosterol and 1,2-hexanediol and p-hydroxyacetophenone pre-mixed antibacterial agent evenly mixed. Stir at 200 rpm for 8 minutes. Add pH adjuster to adjust pH to 6.5. Filter through 100 mesh filter cloth to obtain the hand sanitizer of Examples 1-5.

[0027] Table 1. Raw material ratios for Examples 1-5 (unit: wt%) III. Comparative Examples 1-11 Based on the formulation of Example 3, 11 comparative examples were set up and prepared using the same method. The comparative examples are as follows: Comparative Example 1: Hydroxypropyl-β-cyclodextrin was not added, and the reduced mass was made up with deionized water. The remaining components were the same as in Example 3. Comparative Example 2: No sodium polyglutamate was added; the reduced mass was made up with deionized water; the remaining components were the same as in Example 3. Comparative Example 3: Sodium lauroyl lactyl lactate was not added, and the reduced mass was made up with deionized water. The remaining components were the same as in Example 3. Comparative Example 4: Sodium lauroyl lactyl lactate was replaced with sodium lauroyl glutamate, i.e., the amount of sodium lauroyl glutamate was increased to 9.25 wt%, and the remaining components were the same as in Example 3; Comparative Example 5: Without the addition of sodium lauroyl glutamate, the missing amount was made up by the remaining components cocamidopropyl betaine and decyl glucoside in a mass ratio of 5:2, that is, cocamidopropyl betaine increased to 10.7 wt% and decyl glucoside increased to 4.3 wt%. Comparative Example 6: Sodium lauroyl glutamate was replaced with sodium laureth sulfate, and the remaining components were the same as in Example 3; Comparative Example 7: No cocamidopropyl betaine was added. The missing amount was made up by the remaining components sodium lauroyl glutamate and decyl glucoside in a mass ratio of 8:2, that is, sodium lauroyl glutamate was increased to 12 wt% and decyl glucoside was increased to 3 wt%. The remaining components were the same as in Example 3. Comparative Example 8: Decyl glucoside was not added. The missing amount was made up by the remaining components sodium lauroyl glutamate and cocamidopropyl betaine in a mass ratio of 8:5, that is, sodium lauroyl glutamate was increased to 9.2 wt% and cocamidopropyl betaine was increased to 5.8 wt%. The remaining components were the same as in Example 3. Comparative Example 9: No polylactic acid microspheres were added; the reduced mass was made up with deionized water; the remaining components were the same as in Example 3. Comparative Example 10: A commercially available ordinary hand sanitizer (the main cleaning ingredients are sodium laureth sulfate and cocamidopropyl betaine). Comparative Example 11: A commercially available solvent-based detergent specifically for artists.

[0028] IV. Performance Testing 1. Pigment residue cleaning effect test 1.1 Test Subjects Thirty-two healthy volunteers, half male and half female, with no broken skin or history of allergies on their hands, were randomly divided into 16 groups of two people each.

[0029] 1.2 Test Methods Three 3cm×3cm square test areas were marked on the inside of each volunteer's forearms, for a total of six test areas per person. 0.1g of acrylic paint (bright red acrylic, air-dried for 30 minutes), watercolor paint (deep red watercolor, air-dried for 15 minutes), and matte lipstick (makeup paint, air-dried for 10 minutes) were evenly applied to the three test areas on each arm to form a uniform paint residue layer.

[0030] A single-blind test was conducted, with each group of volunteers corresponding to one test sample. 0.2g of the test hand sanitizer was taken, and the hands were rubbed for 1 minute according to the standard seven-step handwashing method, rinsed with room temperature running water for 10 seconds, and allowed to air dry for 30 minutes.

[0031] Before applying the pigment, the initial skin color value (L*a*b* value) is measured using a skin colorimeter and recorded as E. 初 After applying the pigment, the color values ​​of each area before and after cleaning were recorded as E. 未清洗 and E 清洗后 The color difference value before cleaning is calculated and recorded as ΔE. 未清洗 The color difference value after cleaning is recorded as ΔE. 清洗后 Then calculate the pigment cleaning rate using the formula: Cleaning rate (%) = (ΔE) 未清洗 -ΔE 清洗后 ) / ΔE 未清洗×100%, the average value of each test group is taken, and the results are shown in Table 2.

[0032] 1.3 Test Results Table 2. Cleaning rate (%) of different pigments for each sample group 1.4 Results Analysis Examples 1-5 show a cleaning rate of over 84% for acrylic, watercolor, and lipstick pigments, significantly better than commercially available hand sanitizers. Example 3 exhibits the best overall performance, with cleaning rates of 92.6%, 95.3%, and 90.4%, respectively. The data shows an initial increase followed by a decrease, validating the rationality of the dosage range and the scientific validity of the optimized formulation. The three components of the pigment stripping composite agent demonstrate a significant synergistic effect: the absence of any single component significantly reduces the cleaning rate for all three types of pigments, confirming a synergistic effect through organic inclusion, inorganic dispersion, and interfacial penetration. The three components of the composite surfactant are indispensable; the absence of any component leads to decreased cleaning power due to insufficient wetting penetration, foaming solubilization, or detergency. Replacing with traditional sulfate surfactants did not improve cleaning power and significantly increased irritation, demonstrating the superior "cleaning-mild" balance of the mild surfactant system of this invention. Polylactic acid flexible microspheres can assist in removing pigments embedded deep within textures, complementing chemical cleaning. Overall, this product has cleaning power close to that of solvent-based detergents, while being significantly gentler, filling the gap in gentle, dedicated pigment cleaning products.

[0033] 2. Stimulation test The irritancy of each group of samples was evaluated according to the relevant methods in "SN / T 2329-2025 Eye Irritation / Corrosivity Test of Chicken Embryo Viral Allantoic Membrane in Imported and Exported Cosmetics". The irritation score IS value was calculated based on the phenomena of vascular bleeding, coagulation, and angiolysis. The scoring criteria were: IS < 1 for no irritation, 1 ≤ IS < 5 for mild irritation, 5 ≤ IS < 9 for moderate irritation, and 9 ≤ IS < 21 for severe irritation. The test results are shown in Table 3.

[0034] Table 3 Irritation test results for each group of samples Results analysis: The irritation scores of all embodiments of the present invention are below 0.9, which is considered non-irritating. The mildness is significantly better than that of conventional hand sanitizers and solvent-based hand sanitizers, proving that the formulation system of the present invention has excellent skin compatibility.

[0035] 3. Post-wash moisturizing performance test Twelve volunteers were recruited and randomly divided into three groups of four. After sitting quietly in a constant temperature and humidity room (temperature 22℃, relative humidity 50%) for 30 minutes, the basal skin moisture content and transepidermal water loss (TEWL) value of the inner palm were measured. After washing their hands using the standard method, the samples were left to stand in the same environment for 1 hour, and the corresponding indicators were tested again. The skin moisture retention rate and TEWL change rate were calculated. The results are shown in Table 4.

[0036] Table 4. Moisturizing performance of each group of samples after washing Results Analysis: In Example 3 of this invention, the skin moisture retention rate reached 91.2% one hour after washing, and the TEWL only increased slightly, indicating that the skin barrier was not significantly damaged. In contrast, the comparative examples all showed varying degrees of moisture loss and increased TEWL, with the solvent-based comparative example 11 showing the most significant increase. This proves that the hand sanitizer of this invention can effectively maintain skin moisture and barrier integrity while providing highly efficient cleaning, leaving no tightness or dryness after washing.

[0037] 4. Anti-redeposition performance test Prepare 100 mL of 0.5% iron oxide red pigment suspension, add 1 g of the test hand sanitizer, and place a dried and weighed pure cotton white cloth (2 cm × 2 cm) in the solution. Shake and wash at 30℃ for 10 min. Remove the cloth and rinse 5 times with clean water. After drying at 60℃, measure the whiteness using a whiteness meter. Calculate the whiteness retention rate based on the whiteness of the undyed white cloth. Repeat the experiment 3 times and take the average value. The results are shown in Table 5. The higher the whiteness retention rate, the better the anti-redeposition performance.

[0038] Table 5. Redeposition resistance of each sample group Note: The initial whiteness value (average) is 83.54.

[0039] 5. Stability Test The samples from Example 3 were stored for 3 months under ambient temperature (25°C), high temperature (45°C), and low temperature (-15°C) conditions, respectively, and their appearance was observed. The results showed that the samples remained homogeneous and stable throughout, with no stratification, precipitation, or discoloration, and the polylactic acid microspheres did not aggregate. This indicates that the hand sanitizer system of the present invention has excellent stability and meets the storage requirements of daily chemical products.

[0040] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A hand sanitizer for use with pigment residue, characterized in that, The hand sanitizer contains the following components by weight percentage: 12-18% compound surfactant, 3-6% pigment stripping compound, and 0.5-2% flexible tribospheres; The hand sanitizer also contains excipients and solvents; The composite surfactant is composed of sodium lauroyl glutamate, cocamidopropyl betaine, and decyl glucoside in a mass ratio of (3-5):(2-3):1; The pigment stripping compound is composed of hydroxypropyl-β-cyclodextrin, sodium polyglutamate, and sodium lauroyl lactylate in a mass ratio of (2-3.5):1:(1-2).

2. The hand sanitizer for pigment residue according to claim 1, characterized in that, The hand sanitizer contains the following components by weight percentage: 13.5-16.5% compound surfactant, 4-5.5% pigment stripping compound, and 1-1.5% flexible tribospheres; The composite surfactant is composed of sodium lauroyl glutamate, cocamidopropyl betaine, and decyl glucoside in a mass ratio of (3.5-4.5):(2.25-2.75):

1. The pigment stripping compound is composed of hydroxypropyl-β-cyclodextrin, sodium polyglutamate, and sodium lauroyl lactylate in a mass ratio of (2.5-3.33):1:(1.47-1.77).

3. The hand sanitizer for pigment residue according to claim 1 or 2, characterized in that, The flexible triboelectric microspheres are polylactic acid microspheres with a particle size of 10-50 μm.

4. The hand sanitizer for pigment residue according to claim 1, characterized in that, The excipients include skin conditioning agents, antibacterial agents, and pH adjusters.

5. The hand sanitizer for pigment residue according to claim 1, characterized in that, The solvent is deionized water.

6. The hand sanitizer for pigment residue according to claim 4, characterized in that, The antibacterial agent is a compound of 1,2-hexanediol and p-hydroxyacetophenone in a mass ratio of 2:

1.

7. The hand sanitizer for pigment residue according to claim 4, characterized in that, The skin conditioning agents include ceramide NP, phytosterols, and oat beta-glucan.

8. A method for preparing a hand sanitizer for removing pigment residue as described in claim 7, characterized in that, Includes the following steps: Step 1: Add the amount of deionized water specified in the formula to a container, add oat β-glucan at 200-300 rpm, stir until completely dissolved, and heat to 45-50℃; Step 2: Add the components of the composite surfactant and pigment stripping composite agent in the prescribed amounts in sequence, and stir at a constant speed for 20-30 minutes; Step 3: Add the formulated amount of flexible friction microspheres, stir at 800-1200 rpm for 10-15 min, turn on the cooling water to cool down, and when the system temperature drops to 35-40℃, add the formulated amount of ceramide NP, phytosterol and antibacterial agent, stir evenly, adjust the pH value, filter and discharge to obtain the hand sanitizer.

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