A skin-friendly bath oil and a preparation method thereof

Abstract

The present application relates to the technical field of daily chemical products, especially to IPC A61K8, more particularly to a skin-friendly bath oil and a preparation method thereof. In the present application, 40-75 parts of moisturizing agent A, 0.1-5 parts of skin conditioner A, 2-10 parts of surfactant A, 0.1-2 parts of soluble salt, 0.01-2 parts of natural bacteriostatic agent and 5-30 parts of water, 0.1-2 parts of skin conditioner B and 1-10 parts of surfactant B, 0.1-10 parts of moisturizing agent C, 0.001-2 parts of skin conditioner C, 0.001-0.1 parts of essence and 0.001-1 parts of dextrin jointly act, so that the foaming performance, foam stability, stability and use feeling of the bath oil are improved.

Description

Technical Field

[0001] This invention relates to the field of daily chemical products technology, particularly to IPC A61K8, and more specifically to a skin-friendly bath oil and its preparation method. Background Technology

[0002] Essential oils, as highly effective moisturizing active ingredients, are widely used in various serums, creams, foundations, and even shampoos. With societal development, people have increasingly higher demands for their overall skin health, and new product forms like bath oils are gaining more and more attention from consumers. Bath oils are a blend of shower gel and body oils, possessing the same foaming cleansing components as shower gels while being rich in essential oils and plant extracts. They moisturize the skin during bathing, and their pleasant and unique aroma makes bathing more comfortable and relaxing.

[0003] Children's skin barriers are more fragile than adults' and are more susceptible to external stimuli, leading to skin damage. Therefore, it is necessary to develop bath oils that are gentle on children's eyes and skin, soap-free, neutral in formula, and provide a mild cleansing effect.

[0004] In modern society, poor sleep habits and increasingly harsh environments can make skin prone to allergies, and the skin that recovers from an allergic reaction is extremely delicate. Ordinary shower gels may further irritate the skin. Therefore, there is a need to develop a skin-friendly shower oil suitable for children and people with allergies.

[0005] Existing patent CN202011430120.7 discloses a bath oil and its preparation method, comprising 35-55% plant oil, 20-40% detergent, 0.1-1.0% antioxidant, and 20-40% emulsifier. However, excessive amounts of detergent and emulsifier can easily irritate sensitive skin.

[0006] Existing patent CN201910311473.6 discloses a mild bath oil and its preparation method, comprising the following components in parts by weight: 10-50 parts of surfactant, 1-10 parts of moisturizer, 5-20 parts of synthetic oil, 5-20 parts of plant oil and 0.1-1 parts of white willow bark extract. However, the oil content is too high, resulting in less foam and a poor user experience. Summary of the Invention

[0007] To address the problems in the prior art, the first aspect of this invention provides a skin-friendly bath oil, comprising phase A, phase B, and phase C; by mass parts,

[0008] Phase A comprises 40-75 parts of moisturizer A, 0.1-5 parts of skin conditioning agent A, 2-10 parts of surfactant A, 0.1-2 parts of soluble salt, 0.01-2 parts of natural antibacterial agent, and 5-30 parts of water;

[0009] Phase B comprises 0.1 to 2 parts of skin conditioning agent B and 1 to 10 parts of surfactant B;

[0010] Phase C comprises 0.1 to 10 parts of moisturizer C, 0.001 to 2 parts of skin conditioning agent C, 0.001 to 0.1 parts of fragrance, and 0.001 to 1 part of dextrin.

[0011] More preferably, the skin-friendly bath oil comprises phase A, phase B, and phase C; by mass parts,

[0012] Phase A comprises 60-71 parts of moisturizer A, 0.3-0.8 parts of skin conditioning agent A, 4.5-8.0 parts of surfactant A, 0.7-0.8 parts of soluble salt, 0.01-0.1 parts of natural antibacterial agent, and 15-22 parts of water;

[0013] Phase B comprises 0.1 to 0.3 parts of skin conditioning agent B and 2.5 to 3.5 parts of surfactant B;

[0014] Phase C comprises 1 to 5 parts of moisturizer C, 0.001 to 0.3 parts of skin conditioning agent C, 0.001 to 0.1 parts of fragrance, and 0.001 to 0.1 parts of dextrin.

[0015] Preferably, the moisturizer A and moisturizer C include one or more of glycerin, diglycerin, polyglycerin, 1,2-hexanediol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, and polyethylene glycol.

[0016] Preferably, the skin conditioning agent A includes at least one of TEA salt of cocoyl glutamate, sodium lauroyl glutamate, and potassium cocoyl glutamate.

[0017] Preferably, the surfactant A comprises one or more of the following: cocamidopropyl betaine, sodium cocoyl glycinate, potassium cocoyl glycinate, sodium lauroyl sarcosinate, sodium lauroamphoacetate, lauryl hydroxysulfonate, sodium palmitoyl sarcosinate, and sodium lauroyl aspartate.

[0018] Preferably, the mass ratio of cocamidopropyl betaine to sodium lauroyl sarcosinate is (2-5):(1-5); more preferably, it is (4-5):(2-3); even more preferably, it is 4.5:2.7.

[0019] In this invention, by controlling the mass ratio of surfactant A to surfactant B to be (2-10):3, and especially when the mass ratio of cocamidopropyl betaine, sodium lauroyl sarcosinate, and lauryl ether-3 is (2-5):(1-5):3, the foaming power of the skin-friendly bath oil is improved. Different surfactants have different foaming abilities, with no discernible pattern. In this invention, cocamidopropyl betaine, sodium lauroyl sarcosinate, and lauryl ether-3 are specifically selected and compounded in a specific ratio, significantly reducing the surface tension of water. When the skin-friendly bath oil is used, the hydrophilic groups of the surfactants extend into the aqueous solution, and the lipophilic groups extend into the air bubbles, forming an oriented monolayer at the gas-liquid interface of the bubbles. When the bubbles rise to the liquid surface, they adsorb cocamidopropyl betaine, sodium lauroyl sarcosinate, and lauryl ether-3, forming a bilayer. As bubbles are continuously generated, a dense foam is obtained. As a bath oil, consumers prefer a lot of dense foam and the ability to play with the foam during bathing. However, the inventors found in experiments that although the bubbles are dense, they do not last long and the foam disappears quickly, which can easily lead to a poor bathing experience for consumers.

[0020] Preferably, the water-soluble salt includes one or more of sodium chloride, tetrasodium EDTA, disodium EDTA, and ammonium chloride.

[0021] Preferably, the natural antibacterial agent includes one or more of p-hydroxyacetophenone, ethylhexylglycerin, and glyceryl decanoate.

[0022] Preferably, the skin conditioning agent B includes one or more of olive (Olea europaea) fruit oil, sunflower (Helianthus sannuus) seed oil, tea (Camellia sinensis) seed oil, and apricot (Prunus armeniaca) kernel oil.

[0023] Preferably, the mass ratio of olive (OLEA EUROPAEA) fruit oil to sunflower (HELIANTHUS ANNUUS) seed oil is (1-5):1; more preferably, it is (1-3):1; even more preferably, it is 1:1.

[0024] Preferably, the surfactant B includes at least one of lauryl ether-3, sodium lauryl ether-5 carboxylate, and lauryl ether-7.

[0025] Preferably, the mass ratio of surfactant A to surfactant B is (2-10):3; more preferably, it is (6.5-8):3; even more preferably, it is 7.2:3.

[0026] Preferably, the mass ratio of the cocoyl glutamic acid TEA salt to surfactant A and surfactant B is (0.1-5):(2-10):3; more preferably, it is 0.58:7.2:3.

[0027] In this invention, the foam stability of skin-friendly bath oil was improved by adding 0.1 to 5 parts of cocoyl glutamic acid (TEA) salt. The inventors unexpectedly discovered that the foam disappearance time was prolonged after adding TEA salt. The inventors believe that the addition of TEA salt may increase the surface viscosity of the liquid film in systems containing fruit oils and plant oils, thereby increasing foam stability and extending foam lifespan.

[0028] Furthermore, controlling the mass ratio of cocoyl glutamate TEA salt to surfactant A and surfactant B to be (0.1–5):(2–10):3 effectively emulsifies equal amounts of olive (OLEA EUROPAEA) fruit oil and sunflower (HELIANTHUS ANNUUS) seed oil in this system, thereby improving the stability of the skin-friendly bath oil and preventing phase separation during long-term transportation or storage. The inventors have creatively discovered that in this system, the above-mentioned surfactants, combined with olive (OLEA EUROPAEA) fruit oil and sunflower (HELIANTHUS ANNUUS) seed oil, exhibit the best emulsification effect, allowing the bath oil to maintain good stability under different environments and preventing precipitation.

[0029] Preferably, the skin conditioning agent C comprises at least three of the following: lactobacillus fermentation product, turmeric root extract, gardenia fruit extract, honeysuckle flower extract, and magnolia extract.

[0030] Preferably, the fragrance is a daily-use fragrance.

[0031] In this invention, by adding a portion of dextrin, the stability and solubility of skin conditioning agent B can be further improved. The inventors hypothesize that in the dextrin molecule, hydroxyl groups are mainly distributed outside the cavity, while glycosidic bonds and oxygen atoms are located inside the cavity; this results in a hydrophobic interior and a hydrophilic exterior. When a portion of dextrin is added, it can encapsulate a small portion of the oils that precipitate due to external stimuli, thereby improving the stability and solubility of skin conditioning agent B, thus maximizing the effect of the oils and better caring for the skin.

[0032] A second aspect of this invention provides a method for preparing a skin-friendly bath oil, comprising the following steps:

[0033] S1: Add phase A into the main pot, heat to 70-80℃, and mix until completely dissolved;

[0034] S2: Add phase B to the container, heat to 40-50℃, and after it is completely dissolved, add it to the main pot; heat to 55-65℃ and mix until completely dissolved;

[0035] S3: Add the moisturizing agent C and skin conditioning agent C from phase C to the container, stir to dissolve, add phase C to the main pot, and mix at 40-50℃ until completely dissolved;

[0036] S4: After the temperature cools down to 30-40℃, discharge the material to obtain skin-friendly bath oil.

[0037] Beneficial effects

[0038] 1. In this invention, by controlling the mass ratio of surfactant A to surfactant B to be (2-10):3, especially when the mass ratio of cocamidopropyl betaine, sodium lauroyl sarcosinate, and lauryl ether-3 is (0.1-5):(2-10):3, the foaming power of the skin-friendly bath oil is improved.

[0039] 2. In this invention, by adding 0.1 to 5 parts of cocoyl glutamic acid (TEA) salt, the foam stability of the skin-friendly bath oil is improved.

[0040] 3. In this invention, by adding and controlling the mass ratio of cocoyl glutamic acid TEA salt and surfactant A to surfactant B to (0.1-5):(2-10):3, equal amounts of olive (OLEAEUROPAEA) fruit oil and sunflower (HELIANTHUS ANNUUS) seed oil can be emulsified well in this system, thereby improving the stability of the skin-friendly bath oil and preventing phase separation during long-term transportation or storage.

[0041] 4. In this invention, by adding a portion of dextrin, the stability of skin conditioner B can be further improved, as can its solubility.

[0042] 5. In this invention, 40-75 parts of moisturizer A, 0.1-5 parts of skin conditioning agent A, 2-10 parts of surfactant A, 0.1-2 parts of soluble salt, 0.01-2 parts of natural antibacterial agent, 5-30 parts of water, 0.1-2 parts of skin conditioning agent B, 1-10 parts of surfactant B, 0.1-10 parts of moisturizer C, 0.001-2 parts of skin conditioning agent C, 0.001-0.1 parts of fragrance, and 0.001-1 part of dextrin work together to improve the foaming performance, foam stabilization performance, stability, and user experience of the bath oil. Attached Figure Description

[0043] Figure 1This is a graph showing the foam height of the bath oil in Example 1;

[0044] Figure 2 This is a graph showing the foam height of the bath oil in Comparative Example 1;

[0045] Figure 3 The graph shows the results of stratum corneum moisture content in Example 1 and Comparative Example 1. Detailed Implementation

[0046] Example 1

[0047] Example 1 provides a skin-friendly bath oil. Some of the raw materials were purchased from the following manufacturers: glycerin from PROCTER & GAMBLE INTERNATIONAL OPERATIONS SA SINGAPORE BRANCH; lauryl ether-3 from Kao (Shanghai) Chemical Co., Ltd.; olive (OLEA EUROPAEA) fruit oil and sunflower (HELIANTHUS ANNUUS) seed oil from Northstar Lipids Ltd.; and daily-use fragrance from Shanghai Heyun Fragrance & Flavor Co., Ltd. All other raw materials were commercially available. See Table 1 for details.

[0048] Table 1

[0049]

[0050]

[0051] The second aspect of this embodiment provides a method for preparing a skin-friendly bath oil, comprising the following steps:

[0052] S1: Add phase A into the main pot, heat to 75°C, and mix until completely dissolved;

[0053] S2: Add phase B to the container, heat to 45℃, and after it is completely dissolved, add it to the main pot; heat to 55-65℃ and mix until completely dissolved;

[0054] S3: Add the glycerin, gardenia fruit extract and dextrin from phase C to the container and stir to dissolve. Add all the ingredients from phase C to the main pot and mix at 45°C until completely dissolved.

[0055] S4: After the temperature cools down to 35℃, discharge the material to obtain skin-friendly bath oil.

[0056] Comparative Example 1

[0057] The specific implementation method of Comparative Example 1 is the same as that of Example 1, except that the skin-friendly bath oil, by mass parts, includes phase A, phase B and phase C;

[0058] Phase A comprises 62.1190 parts glycerol, 2.7000 parts cocamidopropyl betaine, 4.5000 parts potassium cocoyl glycinate, 3.0000 parts sodium cocoyl aminopropionate, 2.0000 parts PEG-7 glyceryl cocoate, 0.2000 parts citric acid, 0.2000 parts caprylyl glycol, and 20.8000 parts water;

[0059] Phase B comprises 3.0000 parts lauryl ether-3, 1.0000 parts PEG-40 hydrogenated castor oil, 0.1100 parts olive (OLEA EUROPAEA) fruit oil, 0.1100 parts sunflower (HELIANTHUS ANNUUS) seed oil, and 0.0500 parts (daily use) fragrance.

[0060] Phase C comprises 0.0250 parts of Lactobacillus fermentation product, 0.1610 parts of Curcuma longa root extract, 0.0100 parts of butylene glycol, 0.0040 parts of 1,2-hexanediol, 0.0081 parts of Gardenia flower extract, and 0.0029 parts of dextrin.

[0061] Comparative Example 2

[0062] The specific implementation of Comparative Example 2 is the same as that of Example 1, except that the surfactant A does not contain sodium lauroyl sarcosinate, and the corresponding missing part is adjusted by skin conditioning agent A, cocoyl glutamate TEA salt.

[0063] Comparative Example 3

[0064] The specific implementation method of Comparative Example 3 is the same as that of Example 1, except that the mass fraction of sodium lauroyl sarcosinate in surfactant A is 0.9 parts, and the corresponding missing part is adjusted by skin conditioning agent A, cocoyl glutamate TEA salt.

[0065] Comparative Example 4

[0066] The specific implementation method of Comparative Example 4 is the same as that of Example 1, except that the mass fraction of sodium lauroyl sarcosinate in surfactant A is 3.9 parts, and the excess part is adjusted with skin conditioning agent A, cocoyl glutamate TEA salt.

[0067] Performance testing

[0068] The subjects were 20 adults with sensitive skin, aged 18-40 years. All subjects had healthy skin and met the voluntary inclusion criteria. They were randomly assigned to two groups of 10 each: one group underwent a foaming test, and the other underwent a moisturizing effect test. The bath oils prepared in Example 1 and Comparative Example 1 were used respectively.

[0069] 1. Foaming property test

[0070] (1) The foam height of the two bath oils was measured using a foam analyzer. The test results are as follows: Figure 1 As shown in Table 2.

[0071] Results: The foam height of the bath oil prepared in Example 1 was 1.9 times that of Comparative Example 1, which means that the foaming degree of the bath oil prepared in Example 1 is better than that of the comparative example.

[0072] Table 2

[0073] Foam height (cm) Example 1 Comparative Example 1 001 110.2 57.2 002 105 60.4 003 107.2 51 average 107.5 56.2

[0074] One group of volunteers wet their hands and the laboratory staff took quantitative samples; 0.4 mL of the bath oil prepared in Example 1 and Comparative Examples 1-4 were taken respectively; 1 mL of water was added; the volunteers rubbed the oil 10 times to create foam, and the foam was observed. The test results are shown in Table 3.

[0075] Results: All 10 volunteers believed that the foaming effect of the bath oil prepared in Example 1 was better than that of the bath oil prepared in the comparative example.

[0076] Table 3

[0077]

[0078]

[0079] 2. Moisturizing effect test

[0080] Laboratory staff marked a 3*3cm box on the inside of the volunteer's arm, and took a 0.2ml sample of blank (water) or the bath oil prepared in Example 1 or Comparative Example 1 within the box. The sample was then rubbed in a circular motion for 10 circles. After rinsing with running water, the sample was equilibrated in a constant temperature and humidity laboratory for 20 minutes. The moisture content (%) of the test site was then measured using a stratum corneum moisture content probe. Specific results are shown in Table 4 and... Figure 3 .

[0081] Results: Ten volunteers used the bath oil. The moisture content data obtained by the stratum corneum moisture content probe showed that the bath oil prepared in Example 1 had a better moisturizing effect and stronger hydration after use.

[0082] Table 4

[0083]

[0084] 3. Appearance and stability tests

[0085] The bath oil prepared in Example 1 and the bath oils prepared in Comparative Examples 1-4 were observed for changes in color, odor, water content, and physical properties to conduct stability tests. Internal control standards for the contents were referenced; if the contents separated, turned yellow, or lost fragrance, the product was considered unqualified. Test temperatures: -15℃ / 5℃ / 10℃ / 15℃ / 25℃ / 37℃ / 45℃ / cycles; Observation periods: 24h / 48h / 1 week / 2 weeks / 3 weeks / 4 weeks / 5 weeks / 6 weeks / 7 weeks / 8 weeks / 9 weeks.

[0086] The sample placed at -15℃ was turbid when it was first taken out, but became clear after being placed at room temperature for 2 hours and 4 hours. The sample did not show any discoloration, odor, or stratification during the entire process. Under other conditions, the sample did not show any turbidity, discoloration, odor, or stratification during the entire process. The stability is recorded as A1.

[0087] The sample placed at -15℃ showed turbidity upon initial removal, but became clear after 2h and 4h at room temperature. No discoloration, odor, or stratification occurred during the entire process. Under other conditions, the sample did not show turbidity, discoloration, odor, or stratification during the entire process. The stability is recorded as A2.

[0088] Samples placed at -15℃ and 5℃ showed turbidity and precipitation immediately upon removal from the container. After being placed at room temperature for 2 hours and 4 hours, the samples became clear. No discoloration, off-odor, or stratification occurred during the entire process. Under other conditions, the samples did not show turbidity, discoloration, off-odor, or stratification during the entire process. The stability was recorded as A3.

[0089] Samples placed at -15℃, 5℃, and 10℃ were initially turbid, but became clear after being placed at room temperature for 2 hours and 4 hours, respectively. No discoloration, off-odor, or stratification occurred during the entire process. Under other conditions, no turbidity, discoloration, off-odor, or stratification occurred during the entire process. The stability was recorded as B1.

[0090] Samples placed at -15℃, 5℃, and 10℃ showed turbidity upon initial removal, but became clear after 2 hours and 4 hours at room temperature. No discoloration, off-odor, or stratification occurred during the entire process. Under other conditions, no turbidity, discoloration, off-odor, or stratification occurred during the entire process, and the stability was recorded as B2.

[0091] Samples placed at -15℃, 5℃, and 45℃ showed turbidity upon initial removal. After being placed at room temperature for 2 hours and 4 hours, the samples still showed precipitation. No discoloration, off-odor, or stratification occurred during the entire process. Under other conditions, the samples did not show turbidity, discoloration, off-odor, or stratification during the entire process. The stability is recorded as C.

[0092] The results are shown in Table 4.

[0093] Results: A 9-week stability observation showed that the bath oil prepared in Example 1 was cloudy only when first taken out of the container at -15℃, and became clear after being placed at room temperature. No discoloration, off-odor, or stratification occurred throughout the process. Compared with other comparative examples, the bath oil prepared in Example 1 exhibited higher stability.

[0094] Table 4

[0095]

[0096]

Claims

1. A skin-friendly bath oil, characterized in that, The formula is shown in the table below. 。 2. A method for preparing the skin-friendly bath oil according to claim 1, characterized in that, Includes the following steps: S1: Add phase A into the main pot, heat to 70-80℃, and mix until completely dissolved; S2: Add phase B to the container, heat to 40-50℃, and after it is completely dissolved, add it to the main pot; heat to 55-65℃ and mix until completely dissolved; S3: Add the moisturizing agent C and skin conditioning agent C from phase C to the container, stir to dissolve, add phase C to the main pot, and mix at 40-50℃ until completely dissolved; S4: After the temperature cools down to 30-40℃, discharge the material to obtain skin-friendly bath oil.

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