A plant-based, sulfate-free amino acid oily cleansing composition, and a method of preparing and using the same

Abstract

The application discloses a plant-based sulfate-free amino acid oily cleaning composition and a preparation method and application thereof. The system is a low-water oily cleaning system with amino acid surfactant as the core and compounded carboxylic acid mild surfactant, does not contain sulfate surfactant, and reduces the dependence on traditional large amounts of water, alcohol and PEG ether cosolvent. Plant oils such as rice bran oil and grape seed oil are used as base oil, and polar oils or branched fatty alcohols such as C12-15 alcohol benzoate, isostearyl alcohol and hexyl decanol are used, which are neutralized by aminomethyl propanol and coordinated with a small amount of water to realize the stable dispersion or dissolution of lauroyl alanine and other amino acid surfactants in the oily system, and a clear and transparent, moisturizing and mild and easy-to-rinse bath oil or cleansing oil is prepared. Test results show that the system has the characteristics of mild low irritation, fine foam, no tightness and dryness after washing, no obvious oil film residue and the like, is suitable for sensitive skin, dry skin and pure beauty cleaning and care products, and has good application value.

Description

Technical Field

[0001] This invention belongs to the field of daily chemical products, specifically relating to a plant-based sulfate-free amino acid oily cleaning composition, its preparation method, and its application. Background Technology

[0002] As people's living standards improve, consumers are increasingly demanding higher standards for the safety, gentleness, and functionality of personal care products, especially in the body wash sector. Consumers not only require products with excellent cleansing effects but also emphasize their gentle care and nourishing properties for the skin. Sensitive skin care and clean beauty have become core industry trends. Currently, mainstream bath and cleansing products on the market are mainly divided into two categories: one is saponified shower gel, which uses soap base, obtained through the saponification reaction of fatty acids with potassium hydroxide or sodium hydroxide, as its core ingredient, combined with other auxiliary ingredients. However, this type of product has inherent defects such as poor stability and strong alkalinity. Long-term use can easily lead to moisture loss from the skin surface, causing discomfort such as dryness, tightness, and itching, failing to meet the needs of people with sensitive and dry skin. Another type is surfactant-based shower gel, which uses various surfactants as the core cleaning ingredients and is formulated with moisturizing, thickening and other auxiliary ingredients. Although the cleaning power is improved, some surfactants (such as sulfates) have excessive degreasing power and are highly irritating. Long-term use will damage the skin's surface lipid film, damage the skin's natural barrier, reduce the skin's tolerance to external stimuli, and easily cause problems such as sensitivity and redness. At the same time, this type of product generally has the drawbacks of leaving a slippery feeling after use and not cleaning thoroughly, which seriously affects the consumer's user experience.

[0003] Currently available transparent bath oil products primarily use sulfate surfactants such as MIPA and TIPA salts as the core of their cleansing system, combined with a large amount of PEG ethers such as lauryl ether-3 and lauryl ether-4 as solvents. While this system boasts advantages such as excellent transparency and rapid foaming, it suffers from several technical shortcomings: First, sulfate surfactants have strong degreasing power, which can easily damage the skin barrier with long-term use, failing to meet the core requirements of "safe ingredients, gentle and non-irritating" in pure beauty products and the industry trend of sensitive skin care. Second, the use of PEG ether solvents can introduce the risk of dioxane residue, violating pure beauty products' strict standards for ingredient safety. Third, the system itself has a noticeable odor, requiring the addition of large amounts of fragrance to mask it; however, excessive fragrance can further increase the irritation and sensitization risk of the formula, contradicting the needs of sensitive skin care. Fourth, this system does not address the industry pain point of poor compatibility between amino acid surfactants and plant oils, failing to achieve a balance between gentle cleansing and nourishing effects.

[0004] Amino acid surfactants have become a preferred ingredient in gentle cleansing products due to their close pH value to that of human skin, excellent biodegradability, strong skin affinity, and mild, low-allergenic properties. However, in existing technologies, solid N-acyl amino acid salts (such as lauroyl alanine) are highly polar and have extremely poor compatibility with non-polar plant oils, making it difficult to achieve stable compounding. To solve this compatibility problem, existing technologies typically introduce large amounts of small molecule alcohols (such as ethanol and propylene glycol) or water as co-solvents to assist in the dissolution of solid N-acyl amino acid salts in plant oil systems. However, this introduces new technical drawbacks: on the one hand, the introduction of small molecule alcohols and water can lead to stability problems such as crystallization, turbidity, and layering in low-temperature environments (<10℃) due to decreased solubility of amino acid surfactants, affecting product storage and use; on the other hand, the introduction of water reduces the product's preservative stability, increases the risk of microbial growth, and weakens the nourishing activity of plant oils, failing to meet the product requirement of "balancing cleansing and nourishment," severely limiting the application and promotion of amino acid surfactants in oil-based cleansing systems.

[0005] Existing bath and cleansing systems all have obvious technical defects: they are either highly irritating, easily damage the skin barrier, and have a high risk of causing allergies, or they have poor stability, poor ingredient compatibility, and cannot achieve both cleansing and nourishing effects. They are all unable to meet the current consumer demand for gentle, safe, highly moisturizing, and highly foaming cleansing products, and are especially unable to adapt to the industry development trend of pure beauty and sensitive skin care.

[0006] Therefore, developing a sulfate-free amino acid oil-based cleaning system that is free from sulfate irritation, has low sensitization risk, enables true dissolution of amino acid surfactants in anhydrous vegetable oil systems, and combines high moisturizing and high foaming properties is of great practical significance and industry application value, and is also a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0007] To address the problems existing in the prior art, this invention provides a plant-based sulfate-free amino acid oil-based cleaning composition, its preparation method, and its application. This composition is a sulfate-free, low-water oil-based cleaning system. It uses amino acid surfactants such as lauroyl alanine as the core, combined with mild carboxylic acid surfactants. The polar coupling of the oil phase structures of rice bran oil, grape seed oil, C12-15 benzoate, isostearyl alcohol, and hexyldecyl alcohol improves the compatibility of the amino acid surfactants in the oil-based system. Simultaneously, the neutralization and adjustment using aminomethylpropanol and trace amounts of water ensures that the composition can still form a clear, homogeneous, mild, and easily rinsed cleaning product under low-water conditions.

[0008] On one hand, the present invention provides a sulfate-free amino acid oil-based cleaning composition comprising the following components: rice bran oil, grape seed oil, C12-15 benzoate, lauroyl alanine, isostearyl alcohol, lauryl ether-5 carboxylic acid, aminomethyl propanol, water, hexyldecyl alcohol, optional fragrance, and antioxidant.

[0009] Specifically, by weight percentage, the composition of each component is as follows: rice bran oil 10-60%, grape seed oil 5-40%, C12-15 benzoyl ester 5-35%, lauroyl alanine 5-20%, isostearyl alcohol 2-15%, lauryl ether-5 carboxylic acid 2-12%, aminomethyl propanol 1-7%, water 0.01-1.0%, hexyl decyl alcohol 0.5-8%, fragrance 0-3%, and antioxidant 0.01-0.2%.

[0010] Specifically, by weight percentage, the composition of each component is as follows: rice bran oil 25-35%, grape seed oil 10-20%, C12-15 benzoyl ester 15-25%, lauroyl alanine 10-14%, isostearyl alcohol 6-10%, lauryl ether-5 carboxylic acid 6-9%, aminomethyl propanol 3.5-5%, water 0.1-0.5%, hexyl decyl alcohol 1-4%, fragrance 0.5-2%, and antioxidant 0.05-0.15%.

[0011] Preferably, the proportions of each component are as follows: 29% rice bran oil (ORYZA SATIVA), 20% C12-15 benzoate, 16% grape seed oil (VITIS VINIFERA), 12% lauroyl alanine, 8% isostearyl alcohol, 7.4% lauryl ether-5 carboxylic acid, 4.275% aminomethylpropanol, 0.225% water, 2% hexyldecyl alcohol, 1% fragrance, and 0.1% pentaerythritol tetra(bis-tert-butylhydroxyhydrogenated cinnamic acid) ester.

[0012] Preferably, the rice bran oil and / or grape seed oil can be replaced with any one or more of olive seed oil, castor seed oil, safflower seed oil, wild soybean oil, rice germ oil, camellia seed oil, sweet almond oil, or almond oil.

[0013] Specifically, the C12-15 benzoate, isostearyl alcohol, and hexyldecyl alcohol can be replaced by any one or more of higher polar esters or branched fatty alcohols, such as octyldodecyl alcohol, isostearic acid, coconut oil acid, and oleic acid.

[0014] Specifically, the lauryl ether-5 carboxylic acid can be replaced by any one or more of lauryl ether-4 carboxylic acid, lauryl ether-6 carboxylic acid, or lauryl ether-13 carboxylic acid.

[0015] Specifically, the aminomethylpropanol can be replaced by any one of tromethamine, tetrahydroxypropyl ethylenediamine, or triethanolamine.

[0016] Specifically, the antioxidant is selected from any one of pentaerythritol tetra(bis-tert-butylhydroxyhydrocinnamic acid) ester, tocopherol, tocopherol acetate, or butylated hydroxytoluene.

[0017] On the one hand, the present invention provides a preparation process for the sulfate-free amino acid oil-based cleaning composition, comprising the following steps: (1) C12-15 alcohol benzoate, lauroyl alanine, isostearyl alcohol, lauryl ether-5 carboxylic acid, aminomethyl propanol, water, hexyldecyl alcohol and antioxidant are added to the main pot in sequence, stirred and heated to 85-90°C, and dissolved until a transparent, lump-free liquid is formed; (2) the temperature is kept at 55-75°C and stirred for 20-60 minutes; (3) rice bran oil, grape seed oil and other basic vegetable oils are added and stirred and cooled to room temperature; optionally, fragrance is added after the temperature drops below 45°C, and stirred until uniform and transparent, and discharged after passing inspection; preferably, the temperature in step (2) is kept at 60-65°C and the stirring time is 40-60 minutes.

[0018] On the other hand, the present invention provides the application of the sulfate-free amino acid oil-based cleaning composition in the preparation of cleaning products. Preferably, the application is in the preparation of bath oil and facial cleansing oil. Preferably, the cleaning product has the characteristics of gentle cleaning, fine foaming, moisturizing without tightness and easy rinsing, and is suitable for the cleansing and care of sensitive skin and dry skin.

[0019] Compared with existing technologies, the present invention has the following beneficial effects: The sulfate-free amino acid oil-based cleaning composition of the present invention does not contain sulfate surfactants, reducing the risk of sulfate irritation from the source; the polar oil coupling system composed of rice bran oil, grape seed oil, C12-15 benzoate, isostearyl alcohol, and hexyldecyl alcohol improves the compatibility between amino acid surfactants and the oil phase; and lauryl ether-5 carboxylic acid, aminomethylpropanol, and trace amounts of water synergistically improve the composition's transparency and cleaning performance. Supplementary tests showed that the sample in the examples did not exhibit irritation in the zebrafish embryo method, and all 30 cases in the human closed patch test showed negative reactions; in consumer use tests, most subjects recognized its fine foam, gentle comfort, easy rinsing, and non-drying feel after rinsing, indicating that the composition combines gentleness, moisturizing sensation, and cleaning experience, and has good prospects for industrial application. Attached Figure Description

[0020] Figure 1 This is the result of the uniformity verification of the sulfate-free amino acid oil-based cleaning composition of Example 1.

[0021] Figure 2 These are layered photos of the proportioned recipe. Detailed Implementation

[0022] The present invention will be further described below with reference to specific embodiments, and the advantages and features of the present invention will become clearer as a result of the description. However, these embodiments are merely illustrative and do not constitute any limitation on the scope of protection defined by the claims of the present invention.

[0023] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that the upper and lower limits of the range and each intermediate value between them are specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, are also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0024] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0025] Formulations of each component in Examples 1-2 and Comparative Examples 1-3

[0026] This invention provides a sulfate-free amino acid oil-based cleaning composition, and the bath oil prepared according to this composition is shown in Table 1. The formulations of the components in each embodiment and comparative example are also provided. Example 1 is a preferred formulation for a supplementary test sample.

[0027] Table 1. Formulation components (mass percentage) of each embodiment

[0028]

[0029] The preparation process of this composition is as follows:

[0030] (1) Add the raw materials numbered 2, 4, 6, 7, 8, 9, and 11 into the main pot in sequence, stir and heat to 85-90℃, stir and dissolve evenly until the liquid is transparent and free of lumps;

[0031] (2) Keep warm to 60-65℃ and stir for 40-60 minutes;

[0032] (3) Add the basic vegetable oil raw materials of serial number 1 and 3, stir and cool down to room temperature; optionally, add the fragrance of serial number 10 after the temperature drops below 45℃, stir until uniform and transparent, and discharge after inspection.

[0033] Performance Evaluation

[0034] To verify the technical effect of the sulfate-free amino acid oil-based cleaning system of the present invention, the properties and stability of the samples prepared in Examples 1-2 and Comparative Examples 1-3 were evaluated; and the sample obtained in Example 1 was selected for foam morphology, mildness, human patch application and consumer use tests.

[0035] (1) Evaluation of properties and stability

[0036] Test method: Take 100g of each of the bath oil samples prepared in Examples 1-2 and Comparative Examples 1-3, put them into transparent test bottles and seal them. Place the test bottles under normal temperature (25℃), high temperature (45℃ constant temperature oven) and low temperature (5℃ refrigerator, -8℃ refrigerator) conditions respectively, and observe the appearance of the samples after standing for the initial period, 1 week and 4 weeks. Record whether turbidity, crystal precipitation or stratification occurs.

[0037] Test Results: The stability test results for each group of samples are shown in Table 2; Examples 1 and 2 remained clear, transparent, homogeneous, and without stratification under all stability conditions, and their homogeneity verification results are shown in Table 2. Figure 1 Comparative Examples 1-3 exhibited unstable phenomena such as stratification or low-temperature crystallization. Typical stratification states are shown below. Figure 2 .

[0038] Table 2. Stability of formulations in each example and comparative example

[0039]

[0040] As shown in Table 2, the bath oils prepared in Examples 1 and 2 remained clear and transparent, without layering or crystallization, under normal, high, and low temperature conditions. Comparative Examples 1 and 2 showed layering under normal or low temperature conditions, while Comparative Example 3 showed crystallization under low temperature conditions. This indicates that the synergistic ratio between C12-15 benzoic acid esters, isostearyl alcohol, lauryl ether carboxylic acid components and base vegetable oils plays an important role in maintaining the transparency, uniformity, and stability of the oil-based amino acid system.

[0041] (2) Foam performance test (mixer foaming method)

[0042] Test Method: This test aims to simulate the mechanical shearing foaming process generated when consumers use a foaming net or bath sponge during actual bathing. Accurately weigh 5.0g of the test sample and add it to a graduated transparent homogenizer or tissue homogenizer pre-filled with 95.0mL of standard hard water (temperature controlled at 35±1℃). Turn on the instrument and stir at a constant speed of 3000r / min for 60 seconds. After stopping stirring, observe the appearance, density, and skin feel of the foam.

[0043] Test results: The foam morphology of the sample from Example 1 was compared with that of commercially available sulfate-based bath oil. The results are shown in Table 3.

[0044] Table 3. Foam Performance Test Results (Mixer Foaming Method)

[0045]

[0046] As shown in Table 3, the sample of Example 1 can form a finer and denser foam morphology under mechanical shearing conditions, indicating that the low water-oil-based amino acid cleaning system of the present invention can still achieve a good foaming experience while maintaining the moisturizing feel of the oil phase.

[0047] The following zebrafish embryo method mild and non-irritating test, human skin closed patch test and consumer use test all used the sample obtained in Example 1 as the test sample to verify the mildness, safety and actual user experience of the preferred embodiment; Example 2 and Comparative Examples 1-3 are mainly used for the above stability difference comparison.

[0048] (3) Zebrafish embryo method: a mild and non-irritating test

[0049] The experiment was designed according to "T / HPCIA 006-2022 Determination of Mild Irritation of Cosmetics - Zebrafish Embryo Method" to verify the mild and non-irritating efficacy of the sample in Example 1 with blank control and positive control.

[0050] Table 4. Effects of the sample on the number of wriggling movements in zebrafish embryos

[0051]

[0052] The results showed that there was no significant difference between the sample group in Example 1 and the blank control group (p>0.05), indicating that the sample at a concentration of 1% had no irritating effect on zebrafish embryos.

[0053] (4) Human skin closed patch test

[0054] In accordance with the 2015 edition of the "Cosmetic Safety Technical Specifications", a closed patch test was conducted on human skin. The sample obtained in Example 1 was used as the test substance. The test substance was diluted into a 1% aqueous solution and applied to the normal skin on the flexor side of the subject's forearm. The patch was removed after 24 hours, and the skin reaction was observed at 30 min, 24 h, and 48 h after removal. The test results are shown in Table 5.

[0055] Table 5. Results of human skin occlusive patch test

[0056]

[0057] The results showed that the test substance and the blank control had negative reactions at the observation time points of 30 min, 24 h and 48 h, indicating that the sample of Example 1 had no obvious adverse reactions to humans.

[0058] (5) Consumer usage test

[0059] According to report number ZYXF20260626-003, a 7-day consumer use test was conducted on the bath oil sample obtained in Example 1, and the percentage of people who scored N≥4 (satisfied / very satisfied) was counted.

[0060] Table 6. Summary of Consumer Usage Test Results

[0061]

[0062] The results showed that the subjects gave good feedback on the gentleness, rinseability and moisturizing feel of the sample in Example 1. In particular, the approval rate reached 100% in indicators such as "gentle cleaning process without stinging, itching or discomfort", "no obvious oil film residue, no slippery or sticky feeling" and "skin does not feel tight or dry after bathing".

[0063] Therefore, based on the sample from Example 1 and the results of supplementary tests, the preferred formulation of the sulfate-free amino acid oil-based cleaning system (bath oil) determined in this application is shown in Table 7.

[0064] Table 7. Preferred Formulas for Transparent Amino Acid Bath Oils

[0065]

[0066] The basic vegetable oils listed in numbers 1 and 3 can be replaced with basic vegetable oils such as olive seed oil (OLEA EUROPAEA), castor seed oil (RICINUS COMMUNIS), safflower seed oil (CARTHAMUS TINCTORIUS), wild soybean oil (GLYCINE SOJA), rice germ oil (ORYZA SATIVA), camellia seed oil (CAMELLIA JAPONICA), sweet almond oil (PRUNUS AMYGDALUSDULCIS), or apricot kernel oil (PRUNUS ARMENIACA).

[0067] Raw materials numbered 2, 5, and 9 can be replaced with higher polar esters or branched fatty alcohols such as octyl dodecanol, isostearic acid, coconut oil acid, and oleic acid.

[0068] Raw material number 6 can be replaced with any one or more of lauryl ether-4 carboxylic acid, lauryl ether-6 carboxylic acid, or lauryl ether-13 carboxylic acid.

[0069] Raw material number 7 can be replaced with tromethamine, tetrahydroxypropyl ethylenediamine or triethanolamine.

[0070] Raw material number 11 can be replaced with tocopherol (vitamin E), tocopherol acetate, or butylated hydroxytoluene.

[0071] This invention demonstrates that, through component selection and precise formulation, the system can simultaneously meet requirements such as skin-friendly balance, gentle and low-irritation properties, transparency and uniformity, and easy rinsing. By utilizing polar oil coupling technology and a low-water neutralization system, the compatibility of amino acid surfactants in the oil-based system can be improved while maintaining a high plant oil content, thus satisfying consumers' dual needs for moisturizing cleansing and a gentle experience, and has significant practical value.

[0072] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A plant-based, sulfate-free, amino acid-based oil-based cleaning composition, characterized in that, It includes the following components: rice bran oil, grape seed oil, C12-15 alcohol benzoate, lauroyl alanine, isostearyl alcohol, lauryl ether-5 carboxylic acid, aminomethyl propanol, water, hexyl decyl alcohol, optional fragrance, and antioxidants.

2. The composition according to claim 1, characterized in that, The composition of each component by weight percentage is as follows: rice bran oil 10-60%, grape seed oil 5-40%, C12-15 benzoyl ester 5-35%, lauroyl alanine 5-20%, isostearyl alcohol 2-15%, lauryl ether-5 carboxylic acid 2-12%, aminomethyl propanol 1-7%, water 0.01-1.0%, hexyl decyl alcohol 0.5-8%, fragrance 0-3%, antioxidant 0.01-0.2%.

3. The composition according to claim 2, characterized in that, The components, by weight percentage, are as follows: rice bran oil 25-35%, grape seed oil 10-20%, C12-15 benzoate 15-25%, lauroyl alanine 10-14%, isostearyl alcohol 6-10%, lauryl ether-5 carboxylic acid 6-9%, aminomethyl propanol 3.5-5%, water 0.1-0.5%, hexyl decyl alcohol 1-4%, fragrance 0.5-2%, and antioxidant 0.05-0.15%. Preferably, the components are as follows: rice bran oil 29%, C12-15 benzoate 20%, grape seed oil 16%, lauroyl alanine 12%, isostearyl alcohol 8%, lauryl ether-5 carboxylic acid 7.4%, aminomethyl propanol 4.275%, water 0.225%, hexyl decyl alcohol 2%, fragrance 1%, and pentaerythritol tetra(bis-tert-butylhydroxyhydrogenated cinnamic acid) ester 0.1%.

4. The composition according to claim 1, characterized in that, The rice bran oil and / or grape seed oil may be replaced with any one or more of olive seed oil, castor seed oil, safflower seed oil, wild soybean oil, rice germ oil, camellia seed oil, sweet almond oil, or almond oil.

5. The composition according to claim 1, characterized in that, The C12-15 benzoate, isostearyl alcohol, and hexyldecyl alcohol can be replaced by any one or more of the higher polar esters or branched fatty alcohols, such as octyldodecyl alcohol, isostearic acid, coconut oil acid, and oleic acid.

6. The composition according to claim 1, characterized in that, The lauryl ether-5 carboxylic acid may be replaced by any one or more of lauryl ether-4 carboxylic acid, lauryl ether-6 carboxylic acid, or lauryl ether-13 carboxylic acid.

7. The composition according to claim 1, characterized in that, The aminomethylpropanol can be replaced by any one of tromethamine, tetrahydroxypropyl ethylenediamine, or triethanolamine.

8. The composition according to claim 1, characterized in that, The antioxidant is selected from any one of pentaerythritol tetra(bis-tert-butylhydroxyhydrocinnamic acid) ester, tocopherol, tocopherol acetate, or butylated hydroxytoluene.

9. A preparation process for the composition according to any one of claims 1-8, characterized in that, The process includes the following steps: (1) C12-15 alcohol benzoate, lauroyl alanine, isostearyl alcohol, lauryl ether-5 carboxylic acid, aminomethyl propanol, water, hexyldecyl alcohol and antioxidant are added to the main pot in sequence, stirred and heated to 85-90℃, and dissolved until a transparent liquid without lumps is formed; (2) the temperature is kept at 55-75℃ and stirred for 20-60 minutes; (3) rice bran oil, grape seed oil and other basic vegetable oils are added and stirred and cooled to room temperature; optionally, when the system temperature drops below 45℃, fragrance is added and stirred until it is uniform and transparent. After passing the inspection, the material is discharged; preferably, the temperature in step (2) is 60-65℃ and the stirring time is 40-60 minutes.

10. The use of the composition according to any one of claims 1-8 in the preparation of a cleaning product, preferably, the use is in the preparation of a bath oil or facial cleanser, preferably, the cleaning product has the characteristics of gentle cleansing, fine foaming, moisturizing without tightness and easy rinsing, and is suitable for the cleansing and care of sensitive skin and dry skin.

Images