A lactic acid-based shampoo essence and its preparation method

Abstract

This invention relates to a lactic acid-based shampoo essence and its preparation method. The shampoo essence of this invention comprises lactic acid, a cationic conditioning agent complex, a mild surfactant, a moisturizer, a skin feel modifier, a chelating agent, a preservative, a pH adjuster, and deionized water. Lactic acid is used as the main active ingredient and pH adjusting ingredient. The overall product presents a water-like, highly fluid liquid form. It not only regulates the scalp microecology and provides efficient scalp care, but also has excellent hair conditioning function. While providing excellent immediate cleansing and a refreshing feel, it can form a uniform and long-lasting lightweight conditioning film on the hair surface, thereby achieving a balance between quick rinsing and long-lasting smoothness.

Description

Technical Field

[0001] This invention belongs to the field of daily chemical products, specifically relating to a lactic acid-based shampoo essence and its preparation method. Background Technology

[0002] As consumers gain a deeper understanding of scalp and hair care, market demand has shifted from basic cleansing and dandruff removal to a more refined approach that emphasizes both "scalp health maintenance" and "hair aesthetic repair." Against this backdrop, shampoos with organic acids as functional ingredients are gaining popularity due to their claimed effects such as "pH balancing" and "scalp purification." Currently, shampoos based on the concept of "acid" primarily focus on cleansing, dandruff removal, and volume. Their acidity often originates from fermentation products, resulting in unstable pH levels and insufficient smoothing effects on dyed or dry hair. Traditional smoothing shampoos (especially 2-in-1 products) often rely on silicone oil or high-content cationic conditioning agents. While providing smoothness, these can burden the scalp, causing flatness, and lack the ability to actively regulate the scalp's health environment.

[0003] Existing technologies, particularly acidic conditioning shampoos featuring apple cider vinegar, typically use fermented apple cider vinegar extract as their main acidic ingredient and a key selling point. The underlying technology utilizes the acetic acid and small amounts of organic acids in vinegar to lower the shampoo's pH level, helping to close hair cuticles and remove mineral residue from hard water. However, this technology has significant drawbacks: 1. Complexity and instability of ingredients: Apple cider vinegar is a natural fermentation product. Its acidity, types and contents of organic acids are greatly affected by raw materials and processes, resulting in significant pH fluctuations between product batches, which affects the stability and reproducibility of efficacy.

[0004] 2. Limitations of efficacy: Its main functions focus on cleaning and hair shine. Although it has some antibacterial properties, it has a weak ability to regulate scalp keratin metabolism and lacks a systematic repair function for damaged hair. Its smoothing and anti-static effects are often insufficient.

[0005] 3. Poor sensory experience: The strong vinegar smell needs to be masked with a lot of fragrance, and the formula is mostly a traditional high-viscosity emulsion system, which sacrifices the smooth experience needed by dry or damaged hair in pursuit of "cleanliness".

[0006] Repairing shampoos, with cationic conditioning agents at their core, commonly use silicone oil or high-dose cationic polymers to meet repair needs. These shampoos effectively reduce friction and provide instant smoothness by forming a hydrophobic or cationic film on the hair strands. However, their technological shortcomings lie in: 1. Compatibility issues with scalp care: Silicone oil may deposit on the scalp, posing a potential risk of acne or worsening oiliness; high concentrations of cationic conditioners have an excessive affinity for healthy scalps under alkaline or neutral conditions, which may interfere with the normal physiological environment of the scalp.

[0007] 2. Compatibility Challenges with Acidic Systems: Most cationic conditioners exhibit changes in solubility and stability at low pH levels, making them prone to flocculation and precipitation with common anionic surfactants or thickeners in formulations, leading to product failure or surface separation. This fundamentally hinders the integration of "highly effective cationic conditioner" with "stable acidic care" into a single formulation.

[0008] 3. Risk of flat hair: Traditional conditioning systems can easily cause hair roots to flatten, failing to simultaneously satisfy the desire for a refreshing feel for oily scalps and the desire for smoothness for dry hair ends.

[0009] Therefore, there is an urgent need to improve existing technologies. Summary of the Invention

[0010] The technical problem to be solved by the present invention is to provide a lactic acid-based shampoo essence and its preparation method. The shampoo essence of the present invention uses lactic acid as the main active ingredient and pH adjusting ingredient. It has a water-like, highly fluid liquid form. It can not only regulate the scalp microecology and provide efficient scalp care, but also has excellent hair conditioning function. While providing excellent instant cleansing and refreshing skin feel, it can form a uniform and long-lasting lightweight conditioning film on the hair surface, thereby achieving a balance between quick rinsing and long-lasting smoothness.

[0011] The technical solution adopted by the present invention to solve the above problems is as follows: On one hand, the present invention provides a lactic acid-based shampoo essence water, comprising the following components in weight percentage: 0.5-5% lactic acid, 0.8-5% cationic conditioning agent complex, 2-10% mild surfactant, 1-8% moisturizer, 0.01-1% skin feel modifier, 0.04-0.1% chelating agent, 0.1-1% preservative, 0-0.2% pH adjuster, and the balance being deionized water; Based on the total mass of the shampoo essence water as 100%, the cationic conditioning complex contains 0.5-2% cetrimonium chloride, 0.1-1% polyquaternium-10, and 0.2-2% polyquaternium-47.

[0012] In the above technical solution, high-purity lactic acid is used as the core functional ingredient and pH regulating ingredient to construct and maintain a weakly acidic environment (pH 4.5-5.5) that is most favorable to scalp health. The aim is to achieve gentle regulation of keratin metabolism, active repair and support of the scalp barrier, and potential management of microecological balance, thereby improving the health of the scalp from the root. Lactic acid has the following advantages in scalp care: 1. Physiological compatibility: Lactic acid is an organic acid inherent in the skin, with a very low risk of receptor rejection and good biocompatibility, making it suitable for long-term use. 2. Triple mechanism of action: (1) Keratin regulation: As an α-hydroxy acid (AHA), it can gently break the connection between loose and excessively accumulated keratinocytes, promote the metabolism of old and dead keratin, unclog hair follicles, reduce the "fungal culture medium" formed by the mixture of keratin and sebum, and deprive pathogenic bacteria of the breeding ground from the root, thereby preventing dandruff and folliculitis caused by keratin accumulation from the root. (2) Barrier repair and moisturizing: Lactic acid can stimulate the degradation of filaggrin in the skin, producing more natural moisturizing factors, improving the water-holding capacity, moisturizing capacity and barrier integrity of the scalp stratum corneum. A well-hydrated healthy stratum corneum makes the intercellular connections tighter and the physical properties stronger, which can more effectively prevent the colonization of microorganisms and the penetration of irritants. (3) Potential advantages of microecological regulation: A healthy scalp is weakly acidic (pH 4.5-5.5). Lactic acid can effectively establish and maintain this environment, inhibit the excessive reproduction of harmful bacteria (such as Malassezia), thereby helping to maintain the healthy balance of the scalp microecology. In low pH environments, lactic acid exists primarily in a non-dissociated molecular form. This molecular form has good lipid solubility, enabling it to penetrate the cell membrane of microorganisms. Once inside the cell, it dissociates in the near-neutral intracellular pH environment, releasing hydrogen ions. This leads to a decrease in intracellular pH, inhibition of enzyme activity, and disruption of the transmembrane proton gradient, thereby interfering with energy metabolism and achieving mild antibacterial effects. At the same time, lactic acid itself is a carbon source, and some beneficial skin bacteria can utilize lactic acid as nutrition, while Malassezia and others mainly utilize lipids. By providing an alternative carbon source, lactic acid may indirectly affect the nutrient competition among microorganisms.

[0013] In addition, lactic acid has the following advantages over other acidic ingredients: (1) Stable physicochemical properties: High-purity lactic acid is a colorless or slightly yellow clear liquid with no strong odor. Unlike apple cider vinegar, it will not have a negative impact on the color and smell of the product, which greatly enhances the freedom of formulation and the premium feel of the product. (2) Predictable and quantifiable efficacy: The single and clear chemical component makes it possible to have a predictable linear relationship between its added concentration and the pH value and efficacy intensity of the final product, ensuring the consistency between product batches and the reliability of efficacy. (3) Excellent compatibility: Lactic acid has good compatibility with various anionic surfactants, amphoteric surfactants and nonionic surfactants. More importantly, it can coexist stably with cationic conditioners (such as cetrimonium chloride and polyquaternium salts) under acidic conditions. This is the key technology to achieve the coexistence of "cleaning" and "repairing" in the same formulation.

[0014] Furthermore, in the aforementioned technical solution, the cationic conditioning agent complex comprises cetrimonium chloride, polyquaternium-10, and polyquaternium-47. Specifically, cetrimonium chloride, as a small-molecule cationic conditioning agent, rapidly adsorbs onto the negatively charged areas of damaged hair, providing basic antistatic and softening effects. Polyquaternium-10 and polyquaternium-47 form a high-molecular-weight cationic network, creating a lightweight, continuous conditioning film on the hair surface. This film significantly repairs the hair cuticle, reduces friction, and delivers excellent wet combing properties and a smooth, shiny feel after drying. When these three components are combined in a specific ratio in an acidic aqueous solution system, they form a breathable, strong, and lightweight conditioning film, with significantly better antistatic effects and improved wet combing compared to the use of any single or any two components. By introducing the aforementioned cationic conditioning agent complex, the aim is to form a lightweight, strong, and breathable conditioning film on the hair surface even without relying on silicone oil or high-viscosity matrices. This mask is designed to provide superior instant smoothness, significant anti-static effects, and long-lasting shine, while preventing flat hair roots.

[0015] This invention relates to a lactic acid-based scalp microecology-regulating shampoo essence. By incorporating lactic acid, an effective ingredient, with pH-regulating components into a water-based shampoo system, and compounding it with a cationic conditioning agent complex composed of cetrimonium chloride, polyquaternium-10, and polyquaternium-47, the resulting shampoo essence not only regulates the scalp microecology and provides highly effective scalp care, but also has excellent hair conditioning properties. Its overall high-flow liquid form allows it to instantly contact and spread on the scalp and hair like a serum, enabling the active lactic acid ingredient to act on the target point with "zero delay." Its keratin regulation and pH regulation efficiency are far higher than that of high-viscosity products. The cleansing sensation brought by lactic acid itself, combined with the residue-free and easy-to-rinse characteristics of the water-based formulation, provides excellent immediate cleansing and a refreshing feel while forming a uniform and long-lasting lightweight conditioning film on the hair surface, thus achieving a balance between quick rinsing, lightweight and residue-free, and long-lasting smoothness.

[0016] Furthermore, the mild surfactant is at least one of cocamidopropyl betaine, decyl glucoside, disodium lauryl ether sulfosuccinate, sodium methyl lauroyl taurate, and sodium cocoyl ethanesulfonate.

[0017] In the above technical solution, the present invention uses one or two of the above-mentioned ingredients in any proportion, which are extremely mild decyl glucoside, combined with sodium methyl lauroyl taurate to provide a delicate amino acid cleansing feel, and disodium lauryl ether sulfosuccinate to balance gentleness and cleaning power. Simultaneously, cocamidopropyl betaine is added to optimize the foam texture and further reduce the irritation of the system.

[0018] Furthermore, the moisturizer is glycerin.

[0019] Among the above technical solutions, glycerin has advantages such as good moisturizing effect, high safety, and low cost. Glycerin is a natural moisturizing factor that can absorb moisture from the air, helping hair maintain moisture balance and making hair smoother and shinier; it is mild in nature, with little irritation to the scalp and hair, and is suitable for all hair types, including sensitive scalps; in addition, glycerin is relatively inexpensive, making it a high-value moisturizing ingredient.

[0020] Furthermore, the skin feel modifier is at least one of PEG-7 coconut oil-based glyceryl ester, propylene glycol, hydrolyzed vegetable protein PG-propylsilanetriol, Argan kernel oil, nut seed oil, and Aloe vera leaf juice.

[0021] In the above technical solutions, PEG-7 coconut oil-based glyceryl ester, a high-performance emollient, greatly improves the spreadability and texture of the formula, resulting in a silky smooth product texture. It is often used as a solubilizer for fragrances and essential oils and leaves a light, non-greasy moisturizing film on the skin / hair, enhancing the post-use feel. Propylene glycol is a classic and highly effective moisturizer and solvent that captures moisture from the air, maintaining the hydration of the hair and scalp cuticle. Simultaneously, it helps other active ingredients penetrate better. Hydrolyzed plant protein PG-propylsilanetriol is a complex skin feel modifier, belonging to silanized proteins. It combines the moisturizing and repairing abilities of hydrolyzed plant proteins with the film-forming and smoothing properties of silanol, forming a light film on the skin or hair surface, providing a silky, non-greasy feel. At the same time, hydrolyzed plant proteins also replenish nutrients to the skin and hair, enhancing moisturizing effects, making the skin softer and smoother, and the hair smoother and easier to comb. Plant oils (argan kernel oil / argan seed oil) and silanized proteins deeply nourish and repair hair. Aloe vera leaf juice, in conjunction with lactic acid, further enhances the product's soothing and moisturizing scalp care properties, improving its gentleness.

[0022] Furthermore, the chelating agent is EDTA-2Na.

[0023] Furthermore, the preservative is at least one selected from octyl glycol, benzyl alcohol, ethylhexylglycerin, phenoxyethanol, and p-hydroxyacetophenone.

[0024] In the above technical solution, the present invention uses one or more of the above ingredients in any proportion. The present invention preferably uses caprylyl glycol, benzyl alcohol, and ethylhexylglycerin as alternatives or synergistic solutions to traditional preservatives to form a "polyol preservative enhancement system". This system not only provides reliable preservative protection, but also brings additional benefits such as reducing irritation, enhancing moisturizing, and promoting the penetration of active ingredients, making every cleansing a care for the scalp barrier.

[0025] Furthermore, the pH adjuster is sodium hydroxide. On the other hand, the present invention also provides a method for preparing the above-mentioned shampoo essence, comprising the following steps: A. Add the chelating agent and mild surfactant to deionized water at 80℃-85℃, stir evenly, and then keep warm to defoam, to obtain material 1; B. Add cationic conditioner complex to material 1 and keep warm. Homogenize until there are no particles, then stir and cool to 45℃-60℃ to obtain material 2. C. Add a humectant to material 2 and stir well to obtain material 3; D. Add skin feel modifier and preservative to material 3, stir evenly to obtain material 4; E. Add lactic acid to material 4 and adjust the pH to 3.5-4.5 with a pH adjuster to obtain the shampoo essence.

[0026] The preparation method of the shampoo essence water of the present invention is simple and suitable for industrial production.

[0027] The present invention has the following beneficial effects: 1. This invention relates to a lactic acid-based shampoo essence water. By incorporating lactic acid, the main active ingredient, along with pH-regulating components into a water-based shampoo system, and compounding it with a cationic conditioning agent complex composed of cetrimonium chloride, polyquaternium-10, and polyquaternium-47, the resulting shampoo essence water exhibits a water-like, highly fluid liquid form. On one hand, it can instantly contact and spread on the scalp and hair strands like a serum, allowing the active lactic acid components to act on the target points with "zero delay." Its keratin-regulating and pH-regulating efficiency is far higher than that of high-viscosity products. The cleansing sensation brought by lactic acid itself, combined with the residue-free and easy-to-rinse characteristics of the water-based formulation, provides excellent immediate cleansing and a refreshing feel while forming a uniform and long-lasting lightweight conditioning film on the hair surface. This achieves a unified effect of quick rinsing, lightweight and residue-free texture, and long-lasting smoothness. This product fundamentally reshapes the cleansing and care process, giving consumers a revolutionary experience of instant penetration, ultimate refreshment, and no colloidal burden. On the other hand, this product achieves precise scalp care by utilizing high-purity lactic acid as its core active ingredient and pH-regulating component. It constructs and maintains a stable, slightly acidic environment (pH 4.5-5.5) optimal for scalp health, gently regulating keratin metabolism, actively repairing and supporting the scalp barrier, and potentially managing the microecological balance, thereby improving scalp health from its root. This shampoo essence provides a new solution for developing innovative shampoo products that combine highly effective scalp care with superior hair conditioning.

[0028] 2. The shampoo essence of the present invention has stable properties, overcoming the technical obstacle that cationic conditioning agents are difficult to be compatible with acidic liquid systems and are prone to failure, as is traditionally understood.

[0029] 3. The preparation method of the shampoo essence water of the present invention is simple and suitable for industrial production. Detailed Implementation

[0030] To make the technical problems, solutions, and advantages of this invention clearer, a detailed description will be provided below with reference to specific examples. However, the scope of protection of this invention is not limited to the following specific embodiments. The described embodiments are merely some, not all, of the embodiments of this invention, and are not intended to limit the invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0031] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0032] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0033] Examples 1-4 of the present invention provide a lactic acid-based shampoo essence, and Comparative Examples 1-3 provide a shampoo composition. The dosage formulas of the raw materials used in their preparation are shown in Table 1 below; the units are by mass percentage.

[0034] Table 1. Raw material formulations for Examples 1-4 and Comparative Examples 1-3

[0035] The preparation method of the shampoo essence water in Example 1 above includes the following steps: A. Add the chelating agent EDTA-2Na and the mild surfactants cocamidopropyl betaine, disodium lauryl ether sulfosuccinate, and decyl glucoside to deionized water at 80°C, stir evenly, and then keep warm to defoam, to obtain material 1; B. Add cationic conditioning agent complex cetrimonium chloride, polyquaternium-10, and polyquaternium-47 to material 1 and keep warm. After homogenization until there are no particles, stir and cool to 50°C to obtain material 2. C. Add glycerin, a humectant, to material 2 and stir well to obtain material 3; D. Add preservatives caprylyl glycol, ethylhexylglycerin, benzyl alcohol, and skin feel modifiers PEG-7 coconut oil glyceryl ester, propylene glycol, hydrolyzed vegetable protein PG-propylsilanetriol, argan kernel oil, nut seed oil, and aloe vera leaf juice to material 3, stir well, and obtain material 4. E. Add lactic acid to material 4 and adjust the pH to 3.5-4.5 with sodium hydroxide, a pH adjuster, to obtain the shampoo essence.

[0036] The methods for preparing shampoo essence or shampoo composition in Examples 2-4 and Comparative Examples 1-3 can be obtained in the same way. If there are components that are not added / replaced, they can be deleted / replaced in the corresponding preparation steps.

[0037] The products prepared in Examples 1-4 and Comparative Examples 1-3 were evaluated for efficacy using instrumental efficacy testing and consumer ratings, and their storage stability was also tested. The testing methods are as follows, and the test results are shown in Table 2.

[0038] 1. Consumer trial of instrument efficacy testing Fifty-six healthy volunteers aged 20 to 30 years, screened and confirmed to have excessive scalp oil secretion, were recruited to undergo scalp oil, scalp moisture, and scalp volume tests. All participants were randomly assigned to seven groups of eight, corresponding to the four embodiments and three comparative examples of this invention. To ensure baseline consistency, volunteers were not allowed to wash their hair the night before the test and were instructed to avoid combing their hair as much as possible during the 48-hour test period to minimize the impact of human intervention on the natural distribution of scalp oil. All procedures were conducted in a strictly controlled temperature and humidity environment, and volunteers were required to sit quietly for 30 minutes beforehand to acclimatize. The shampooing process was performed by the same trained operator, using the exact same massage techniques, 5 ml of product, and rinsing time. After shampooing, the hair was completely dried using a hairdryer on medium heat.

[0039] (1) Scalp oil test: Scalp oil testing method: In this sebum measurement method, a special test tape is bent and fixed into a ring structure, ensuring its ring end face is in full contact with the scalp surface. Upon contact, scalp lipids adhere to the tape surface and alter its light transmittance. The tape is then unfolded and smoothed, placed in the sample-carrying slider of the scalp oil tester, and pushed into the detection chamber. The instrument uses a photoelectric scanning system to read the transmittance data at various locations on the tape, generating a transmittance distribution spectrum. The peak intensity of this spectrum has a quantitative relationship with the adsorbed lipid mass, which can be converted into the oil content per unit area of ​​the scalp. The ring end face serves as the effective working area for sampling in contact with the scalp during this process.

[0040] (2) Scalp moisture test: use The scalp moisture meter collects and records the moisture content of the test area and control area at various test points and time periods. During testing, the ring-shaped tip of the probe is placed precisely over the uneven skin surface or scalp to obtain the corresponding data. The rate of change in scalp moisture before and after sample application is calculated.

[0041] (3) Hair volume test: Images of dry hair were taken before and after sample application using a facial image analyzer. The area of ​​the hair strands was analyzed and calculated using Image-Pro Plus 6.0 to verify the product's effectiveness in improving hair volume. The more points the software identified and the larger the area, the more voluminous the hair. The rate of change in hair volume before and after sample application was calculated.

[0042] 2. Performance testing of the detached hair strand instrument (1) Hair gloss test: The gloss of the smooth hair strand surface was measured using a precision gloss meter. Light is reflected on the front and back surfaces of the hair, and when passing through the hair, it is affected by melanin or micropores, resulting in different degrees of light absorption or scattering, thus exhibiting different gloss levels. The degree of hair damage, the cleanliness of the hair and scalp, and the distribution of deposits on the hair surface are all important factors affecting hair gloss. Using the same batch of real human hair strands, divided into 7 groups, the gloss change rate of the hair strands before and after use was measured to evaluate whether the samples had a gloss effect.

[0043] (2) Dry hair combing strength test: Using real human hair strands, the strands were numbered, rinsed with water at a constant speed of 40℃ for 1 minute, rubbed for 1 minute, and repeated twice. Then rinsed with water at a constant speed of 40℃ for 1 minute. The wet hair strands were gently combed neatly with a comb and hung in a constant temperature and humidity room for more than 4 hours. The combing strength test values ​​of the hair strands before and after the test were obtained. The hair combing instrument was turned on, the instrument displacement was set to 245 mm, and the speed was 300 mm / min. The combing strength curve of each hair strand was tested, ensuring that the starting point of the test for each hair strand was the same and that the hair ends completely through the comb. The test was repeated 3 times, ensuring that the test values ​​differed within 0.004 N. The average combing strength and the rate of change of the average combing strength were calculated.

[0044] 3. Consumer demographic ratings One hundred and forty participants aged 18-50 with itchy, oily scalp and long hair were recruited and randomly divided into seven groups of 20 each. Participants had no history of severe allergies to skincare or haircare products; no serious systemic diseases, immunodeficiency, or autoimmune diseases; and had not used hormonal medications or immunosuppressants within the past week. The seven groups used products from Examples 1-4 and Comparative Examples 1-3 (twice a week). During each wash, a sufficient amount of product was applied to the hair and scalp, gently massaged for three minutes, and then rinsed thoroughly with warm running water. Hair was then blow-dried. Participants agreed not to use any cosmetics that could affect the results or to undergo chemical treatments such as perming or dyeing during the trial. After eight weeks of testing, volunteers rated scalp oil control and comfort levels before and after using the products. A score of 0-10 was used, with higher scores indicating a better user experience.

[0045] 4. Product storage stability test 28-day stability test at 48℃: a. Before placing the sample in a 48℃ oven, record the initial state in detail, including appearance, color, initial odor, whether the texture is uniform, and pH, and take photos for archiving; b. Label the samples and place them in a 48℃ oven; c. Remove samples on days 1, 3, and 7, allow them to cool to room temperature (approximately 30-60 minutes) before observation and evaluation. Thereafter, remove samples weekly for observation and evaluation (i.e., on days 14, 21, and 28). d. Record the following for each observation: Appearance changes: presence or absence of layering, precipitation, crystallization, color darkening / lightening, oil droplet precipitation; Odor changes: Has the odor become sour, rancid, or has other unusual smells? Texture / viscosity change: Whether it has become thinner or thicker compared to the initial record; pH changes: Record whether there are significant fluctuations in pH value; If none of the above indicators change, the product storage stability test is passed.

[0046] Table 2 Performance test results of Examples 1-4 and Comparative Examples 1-3

[0047] According to the test results in Table 2, after using the products of Examples 1-4 and Comparative Example 2 (which added lactic acid), the oil on the scalp was significantly reduced, indicating that lactic acid has a significant oil-controlling effect. A comparison of Examples 1-4 and Comparative Examples 1-3 shows that the lactic acid-added shampoo essence of this invention significantly improves the control of scalp oil secretion. Furthermore, a comparison of Examples 1-4 shows that the oil-controlling effect of the shampoo essence is better with increasing lactic acid content.

[0048] Furthermore, according to the test results in Table 2, comparing Comparative Examples 1-3 reveals that Comparative Example 2, which only added 2% lactic acid, showed a strong improvement in scalp moisture, hair volume, hair shine, dry hair combing ability, and user comfort, indicating that lactic acid has a strong improving effect in these aspects. Comparing Examples 1-4 with Comparative Examples 1-3 shows that Examples 1-4, which simultaneously added lactic acid and a cationic conditioning agent complex, showed a significant improvement in scalp moisture, hair volume, hair shine, dry hair combing ability, and user comfort, indicating that combining lactic acid and a cationic conditioning agent complex into the shampoo essence water can achieve better improvement in these aspects. Comparing Examples 1-3 shows that the higher the lactic acid content, the better the improvement in scalp moisture, hair volume, hair shine, dry hair combing ability, and user comfort. Example 4, which added 4% lactic acid, showed worse effects in these areas compared to Example 3.

[0049] In addition, according to the test results in Table 2, the stability test results show that the products of Examples 1-4 and Comparative Examples 1-3 are all stable systems, indicating that the cationic conditioner complex added in this invention can exist stably in an acidic environment containing lactic acid, overcoming the technical obstacle that cationic conditioners are difficult to be compatible with acidic liquid systems and are prone to failure in the traditional understanding.

[0050] In conclusion, Example 3, with the addition of 3% lactic acid, is the optimal formulation.

[0051] Furthermore, standardized rinsing efficiency tests were conducted on Example 3, Pantene lotion repair shampoo, and Dove silicone-free air-feel shampoo. The test methods are as follows, and the test results are shown in Table 3.

[0052] Standardized rinsing efficiency test method: Samples were used to perform standard cleaning and rinsing on moderately damaged human hair strands of the same length, and the total rinsing time, total water consumption, and wet slipperiness score were recorded.

[0053] Table 3 Standardized Flushing Efficiency Test Results

[0054] As shown in Table 3, the total rinsing time and total water consumption of the sample in Example 3 of this invention are the lowest, even better than the Dove silicone-free air-feel shampoo which claims to be refreshing. The slippery feeling of wet hair during the rinsing stage is lower than that of Pantene lotion repair shampoo and Dove silicone-free air-feel shampoo, indicating that the sample of this invention has high rinsing efficiency and a refreshing feeling during the rinsing stage.

[0055] The adsorption and distribution of fluorescently labeled cations were observed for Example 3 and Pantene emulsion repair shampoo. The test methods are as follows, and the test results are shown in Table 4.

[0056] Method for observing the adsorption and distribution of fluorescently labeled cations: In Example 3 and Pantene emulsion repair shampoo, 0.01% of the same fluorescently labeled cationic conditioner polyquaternium-10 was added respectively. The same real human hair strands were treated with the two labeled products respectively, rinsed and blow-dried, and placed under a laser confocal microscope to observe the fluorescence signal distribution map and quantitatively analyze the data.

[0057] Table 4. Observation results of adsorption and distribution of fluorescently labeled cations

[0058] As shown in Table 4, after treating the hair strands with Pantene emulsion repair shampoo, although the hair strands adsorbed a large amount of cationic conditioner, the cationic conditioner was unevenly distributed and tended to accumulate at the damaged areas. After treating the hair strands with the sample of Example 3 of this invention, although the total adsorption amount of cationic conditioner was low, the film formed was uniform, indicating that the cationic conditioner, with the assistance of the lactic acid and aqueous system, can form a high-quality and effective repair film.

[0059] The lactic acid-based shampoo essence of this invention has a water-like, highly fluid liquid form. It not only regulates the scalp microecology and provides efficient scalp care, but also has excellent hair conditioning function. While providing excellent instant cleansing and refreshing skin feel, it can form a uniform and long-lasting lightweight conditioning film on the hair surface, thereby achieving a balance between quick rinsing and long-lasting smoothness.

[0060] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0061] Furthermore, it should be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0062] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A lactic acid-based shampoo essence, characterized in that, It includes the following components by weight percentage: lactic acid 0.5-5%, cationic conditioning complex 0.8-5%, mild surfactant 2-10%, moisturizer 1-8%, skin feel modifier 0.01-1%, chelating agent 0.04-0.1%, preservative 0.1-1%, pH adjuster 0-0.2%, balance deionized water; Based on the total mass of the shampoo essence water as 100%, the cationic conditioning complex contains 0.5-2% cetrimonium chloride, 0.1-1% polyquaternium-10, and 0.2-2% polyquaternium-47.

2. The shampoo essence water according to claim 1, characterized in that, The mild surfactant is at least one of cocamidopropyl betaine, decyl glucoside, disodium lauryl ether sulfosuccinate, sodium methyl lauroyl taurate, and sodium cocoyl hydroxyethanesulfonate.

3. The shampoo essence water according to claim 1, characterized in that, The moisturizer is glycerin.

4. The shampoo essence water according to claim 1, characterized in that, The skin feel modifier is at least one of PEG-7 coconut oil-based glyceryl ester, Argan kernel oil, nut seed oil, hydrolyzed vegetable protein PG-propylsilanetriol, propylene glycol, and aloe vera leaf juice.

5. The shampoo essence water according to claim 1, characterized in that, The chelating agent is EDTA-2Na.

6. The shampoo essence water according to claim 1, characterized in that, The preservative is at least one of octyl glycol, benzyl alcohol, ethylhexylglycerin, phenoxyethanol, and p-hydroxyacetophenone.

7. The shampoo essence water according to claim 1, characterized in that, The pH adjuster is sodium hydroxide.

8. A method for preparing a shampoo essence as described in any one of claims 1-7, comprising the following steps: A. Add the chelating agent and mild surfactant to deionized water at 80℃-85℃, stir evenly, and then keep warm to defoam, to obtain material 1; B. Add cationic conditioner complex to material 1 and keep warm. Homogenize until there are no particles, then stir and cool to 45℃-60℃ to obtain material 2. C. Add a humectant to material 2 and stir well to obtain material 3; D. Add skin feel modifier and preservative to material 3, stir evenly to obtain material 4; E. Add lactic acid to material 4 and adjust the pH to 3.5-4.5 with a pH adjuster to obtain the shampoo essence.

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