Makeup removing composition

Abstract

The present invention relates to a skin cleansing composition, in particular a composition for washing the face, which is particularly suitable for makeup removal. The composition comprises a synthetic surfactant, a free fatty acid and a specific polymer, and the pH window of the composition is narrow, so that the composition has specific high viscosity and can effectively remove makeup.

Description

Technical Field

[0001] This invention relates to a skin cleansing composition, and more particularly to a composition for washing the face, which is particularly useful and effective for removing makeup. Background Technology

[0002] People enjoy using cosmetics, especially on the face and other exposed areas of the body, for various benefits such as evening skin tone, smoothing age-related fine lines, brightening the complexion, and sun protection. In addition, people use makeup products such as lipstick, foundation, and mascara to beautify their faces to meet individual needs. These products contain a variety of ingredients, which may be particulate, such as pigments, inorganic particles, powders, and sunscreens; oily ingredients, such as organic sunscreens, emollients, and solvents; water-soluble ingredients, such as moisturizers and polymers; and other skin-care active ingredients, such as vitamins and anti-aging active ingredients. These leave-on cosmetics and makeup products are formulated to be highly compatible with the skin. They are claimed to maintain their effectiveness on the skin and remain stable even with prolonged use, such as for 8 to 12 hours, without smudging, becoming dirty, or running even with sweating or exposure to sunlight, pollution, and changing external environments such as heated or air-conditioned rooms. On the one hand, these products must be highly skin-friendly; on the other hand, consumers need a simple, safe, and gentle makeup remover to ensure that these no-rinse cosmetics / makeup products are easily removed without excessive mechanical friction.

[0003] The most commonly used skin cleansing products contain a combination of synthetic surfactants and soap (often referred to as soap-based synthetic detergent compositions) to emulsify oils and particulate matter, thus providing excellent cleansing efficacy. However, such compositions often fall short in terms of facial makeup removal efficiency. The inventors of this invention discovered that makeup removal efficacy is even better when the composition is formulated from a combination of synthetic surfactants (excluding soap) and free fatty acids. However, this type of composition, often referred to as a gel-cream product, lacks the required rheological properties, i.e., the desired feel / viscosity, due to its high water and free fatty acid content. The product must have a certain high viscosity to be easily applied to the face and used for washing without excessive run-off and product waste. Furthermore, the composition also suffers from insufficient formulation stability. They discovered that including a specific polymer, namely a cross-linked acrylate copolymer, can solve this problem within a narrow pH range, enabling the composition to possess not only the required formulation stability but also the required high viscosity. Furthermore, it was found to remain stable under various temperature conditions. Summary of the Invention

[0004] Therefore, one object of the present invention is to provide a facial cleansing composition that can effectively remove makeup.

[0005] Another object of the present invention is to provide a highly effective makeup removal and facial cleansing composition that remains stable under long-term storage and varying temperature conditions.

[0006] Another object of the present invention is to formulate a product that has high makeup removal efficacy, remains stable under prolonged and varying temperature conditions, and is delivered at the required high viscosity for easy application and use.

[0007] This invention relates to a makeup remover composition comprising:

[0008] (i) 1 to 25% by weight of synthetic surfactants;

[0009] (ii) 0.1 to 10% by weight of free fatty acids;

[0010] (iii) 0.1 to 2.5% by weight of a thickener, which is a cross-linked acrylate copolymer;

[0011] (iv) 0.1 to 1% by weight of alkali;

[0012] (iv) 40 to 70% by weight of water;

[0013] The pH value of the composition is in the range of 6.2 to 6.8; and

[0014] The viscosity of the composition is in the range of 15,000 to 35,000 mPa·s. Detailed Implementation

[0015] These and other aspects, features, and advantages will become clear to those skilled in the art upon reading the following detailed description and the appended claims. For the avoidance of doubt, any feature of one aspect of the invention may be applied to any other aspect of the invention. The word “comprising” is intended to mean “including” but does not necessarily mean “consisting of” or “made of”. In other words, the listed steps or options need not be exhaustive. It should be noted that the embodiments given in the following description are intended to illustrate the invention and are not intended to limit the invention to these embodiments alone. Similarly, unless otherwise stated, all percentages are weight / weight percentages. Except for operational and comparative embodiments or otherwise explicitly stated, all figures in this specification and claims indicating the amount of material or reaction conditions, physical properties of the material, and / or uses should be understood to be modified by the word “about”. Numerical ranges expressed in “from x to y” format should be understood to include both x and y. When multiple preferred ranges are described in the form of “from x to y” for a particular feature, it should be understood that all ranges combining different endpoints are also considered.

[0016] The topical compositions of this invention are intended for personal care or cosmetic use and may also be referred to as personal care compositions or cosmetic compositions. As used herein, "personal care composition" means a composition for external use (i.e., for use on the outer surface of human skin and / or hair). Such compositions can be categorized as no-rinse or wash-off types and include any human product used to improve appearance, cleanliness, odor control, or overall aesthetics. The compositions of this invention are preferably wash-off cleansing compositions containing synthetic surfactants.

[0017] As used in this article, “skin” refers to the skin of the face and various parts of the body (such as the neck, arms, hands, legs, and scalp), which are the exposed areas where people typically apply leave-on cosmetic compositions, especially color makeup compositions.

[0018] The compositions of the present invention are of the cleaning type, i.e., the so-called wash-off or rinse-off type. These forms refer to compositions that are typically diluted with water and then applied to a localized surface, such as the face, and rinsed off with plenty of water after a few minutes. The cleaning compositions of the present invention are in liquid form with a viscosity in the range of 15,000 to 35,000 cps (or millipascal-seconds; mPa·s), preferably in the range of 15,000 to 25,000 cps (or millipascal-seconds; mPa·s), more preferably in the range of 16,000 to 22,000 cps (or millipascal-seconds). The composition is preferably a Newtonian fluid. The viscosity of the product was measured using a Brookfield viscometer equipped with an RV6 rotor at 20 rpm (lasting 30 to 60 seconds, preferably 30 seconds) at 25 ± 2°C.

[0019] The compositions of the present invention comprise one or more surfactants selected from anionic, amphoteric, and nonionic surfactants. Preferably, the surfactant is selected from one or two of anionic and amphoteric surfactants, and most preferably a combination of both.

[0020] The anionic surfactant is preferably selected from alkyl ether sulfates, primary alkyl sulfates, secondary alkyl sulfonates, alkylbenzene sulfonates, or ethoxylated alkyl sulfates. Sodium dodecyl ether sulfate (SLES) is particularly preferred. The SLES used in this invention typically preferably has 1 to 3 ethylene oxide (EO) groups. The content of SLES is preferably 3 to 14% of the dry weight of the composition, more preferably 6 to 12%. SLES is typically provided in the form of a 30% aqueous solution. Other surfactants that may be included in this invention are cocamidoyl monoethanolamine (CMEA). The content of CMEA is preferably 1 to 3% of the weight of the composition. A preferred aspect of the liquid cleaning composition of this invention involves a surfactant comprising a mixture of sodium lauryl ether sulfate (SLES) and cocamidoyl monoethanolamine (CMEA). The composition may also contain alkyl polyglucosides, preferably with a carbon chain length of C6 to C4. 16 .

[0021] Another surfactant that can be used in the liquid cleaning composition of the present invention is an amphoteric surfactant, preferably a betaine surfactant, more preferably an alkylamidopropyl betaine surfactant, such as cocamidopropyl betaine. In a preferred embodiment, the composition contains 0.1 to 5% by weight, preferably 0.5 to 4% by weight, more preferably 1 to 3% by weight of an amphoteric surfactant.

[0022] The nonionic surfactants included in the liquid cleaning composition of the present invention are preferably polyoxyethylene sorbitan alkyl esters (sold as Tween surfactants), fatty alcohol ethoxylates (sold as Brij surfactants), alkylphenol ethoxylates (sold as Triton surfactants), fatty acid ethoxylates (sold as Myrj surfactants), and alkyl polyglucosides (sold under the name Plantacare surfactants). The total amount of surfactants included in the composition of the present invention is preferably 5 to 15% by weight of the composition, more preferably 7 to 15%.

[0023] The compositions of the present invention contain 0.1 to 10% by weight of free fatty acids. Free fatty acids refer to the amount of fatty acids present in the composition, excluding any fatty acids that may be converted into soap by the addition of alkali. The content of free fatty acids is preferably 0.1 to 6% by weight of the composition, more preferably 4 to 6%. The free fatty acids preferably contain C10 to C16 fatty acids, more preferably C12 to C14 fatty acids. For the amount of alkali contained in the compositions of the present invention, the amount of soap generated in situ therefrom is at most 1% by weight of the composition, preferably 0.1 to 0.5% by weight.

[0024] The compositions of the present invention comprise a thickener, which is a crosslinked acrylate copolymer. It is a liquid acrylic rheology modifier designed for suspending, stabilizing, and thickening surfactant-based personal care products and soap-based cleaning systems. A particularly preferred copolymer used in the compositions of the present invention is Lubrizol's Carbopol Aqua SF-1 acrylic emulsion polymer. It is particularly suitable for formulations containing high levels of surfactants. It is an alkali-swellable acrylic emulsion polymer. The thickener is present in an amount of 0.1 to 2.5% by weight of the composition, preferably 0.2 to 2.4%. The compositions of the present invention are prepared by adding an alkali thereto. The alkali is added to ensure that the pH of the composition is carefully adjusted to the range of 6.2 to 6.8. The pH of the composition is measured at 25°C using a calibrated pH meter.

[0025] It was observed that outside this pH range, the compositions of the present invention do not possess the desired viscosity. Below pH 6.2, the viscosity drops to an unacceptably low level. As a skin cleansing composition, this is most commonly used for facial makeup removal. In doing so, the foam generated by dilution may come into contact with mucous membranes such as the eyes and nose, causing irritation. Therefore, for such applications, the pH should be as close to 7 as possible, preferably above 6.2. When the pH is above 6.8, a sharp decrease in viscosity of the compositions of the present invention was observed. Therefore, it is important to adjust the pH to the range of 6.2 to 6.8 by carefully adding the required amount of alkali.

[0026] The added base can be one or more of sodium hydroxide, potassium hydroxide, or triethanolamine, with potassium hydroxide being preferred. Depending on the base or combination of bases used, the amount added can be from 0.1 to 10% by weight, preferably from 0.1 to 2% by weight. When potassium hydroxide is used, its amount is preferably from 0.1 to 1% by weight of the dry weight of the composition, more preferably from 0.4 to 0.6%.

[0027] The compositions of the present invention may contain a humectant, which is typically a polyol. Preferably, the humectant is at least one selected from propylene glycol, dipropylene glycol, polypropylene glycol, polyethylene glycol, sorbitol, hydroxypropyl sorbitol, hexanediol, 1,3-butanediol, isopentanediol, 1,3-propylene glycol, pentanediol, hexanediol, 1,2,6-hexanetriol, glycerin, ethoxylated glycerin, and propoxylated glycerin. Preferred humectants are selected from one or more of glycerin, 1,3-butanediol, propylene glycol, 1,3-propylene glycol, pentanediol, hexanediol, and sorbitol. Glycerin is the most preferred humectant. The amount of humectant used is preferably 0.1% to 20% by weight of the composition, more preferably 5% to 15%.

[0028] The composition of the present invention is in the form of a viscous liquid, with a viscosity range as described above. The water content is 40 to 70% by weight of the composition, preferably 40 to 65%, more preferably 50 to 65%.

[0029] The composition may include other known ingredients, such as electrolytes, fragrances, pigments, preservatives, emollients, and sunscreens.

[0030] The present invention will now be illustrated by means of the following embodiments.

[0031] Example

[0032] Example A,1: Makeup removal effect of the composition of the present invention and the control sample

[0033] The compositions according to the present invention (Example 1) are shown in Table 1. The compositions of the control sample (Example A) are shown in Table 2.

[0034] Table 1: Example 1:

[0035] Element weight% Sodium lauryl ether sulfate (70%) 13.5 Cocamidopropyl betaine (30%) 8.0 Myristic acid 3.0 Lauric acid 3.0 Potassium hydroxide (85%) 0.6 Crosslinked acrylate copolymer (30%) 6.5 glycerin 5.0 Propylene glycol 7.0 Phenoxyethanol 0.6 water Up to 100

[0036] The composition has a pH of 6.4 and a viscosity of 26,000.

[0037] Table 2: Example A

[0038] Element weight% Myristic acid 25.00 Palmitic acid 3.85 stearic acid 3.15 Lauric acid 3.00 Potassium hydroxide (85%) 8.33 Decyl glucoside (50%) 5.00 Propylene glycol 7.50 glycerin 22.5 Glycol distearate 3.00 water Up to 100

[0039] The composition has a pH of 9.2 and a viscosity of 70,000.

[0040] The makeup removal effects of the two compositions from Example 1 and Example A were tested. The method used to measure the efficacy is as follows:

[0041] This study aimed to evaluate the cleansing and makeup removal (MUR) efficacy of the tested products. The evaluation employed in vitro assessment techniques. The skin sample used in the study was an artificial skin matrix that mimicked human skin. Its surface morphology, pH value, critical surface tension, chemical reactivity, and ionic strength were similar to human skin. To simulate a real-life scenario, in vitro skin was used as the matrix and exposed to a car exhaust chamber.

[0042] The presence of cosmetics is visible through the color of the skin's surface. The effectiveness of rinsing is determined by assessing the presence of a white undertone to reduce or remove cosmetics.

[0043] Image evaluation is related to visual appearance. The evaluation is based on grayscale assessment using pixels. Analysis is performed using the standard NIH-published software Image J*.

[0044] Determination of the cleaning / MUR efficacy of the test products:

[0045] Step 1: Prepare skin samples: Cut the in vitro skin samples into appropriate shapes and sizes.

[0046] Step 2: Imaging 1: Capture a digital image of a skin sample on a white background.

[0047] Step 3: Makeup: Apply a standard foundation product evenly to a skin sample, then leave it for 10 to 15 minutes before applying other makeup products such as Kajal and lipstick.

[0048] Step 4: Imaging 2: Capture a digital image of the skin sample on a white background.

[0049] Step 5: Rinsing: Pre-wet the in vitro skin sample, spread an appropriate amount of test product on the sample surface, and add water. Rub the sample surface back and forth 5 times in a linear horizontal direction with uniform pressure. Then rinse the surface with running deionized water for 60 seconds.

[0050] Step 6: Drying the skin sample: Dry the in vitro skin sample for 15 minutes under controlled temperature and humidity (25±50℃ and 50±10%RH).

[0051] Step 7: Imaging 3: Capture a digital image of the skin sample on a white background.

[0052] Input the imaging data (images 1, 2, and 3) into the software and calculate the mean and standard deviation of the selected evaluation area using the following formula:

[0053]

[0054] In this case, %clean = (image 3 – image 2) / (image 1 – image 2) × 100.

[0055] It can be seen that, compared with the sample of Example A, the sample of Example 1 spreads more evenly and more easily on the hand.

[0056] Makeup removal efficacy (% cleansing) is summarized in Table 3 below:

[0057] Table 3

[0058] Example %clean 1 96.4 A 15.3

[0059] Compared with the control, the p-value of the data in Example 1 was <0.001.

[0060] The effect of pH on sample viscosity:

[0061] The compositions of Example 1 were prepared at different pH values ​​by varying the amount of alkali used. The viscosity of the samples was measured as described above. The data are summarized in Table 4 below:

[0062] Table 4:

[0063]

[0064] The data in Table 4 above indicate that the optimal pH range for this composition is between 6.2 and 6.8. Below this range, the viscosity decreases slightly. Furthermore, these low pH ranges are not recommended due to their skin-friendly nature. Above the desired pH range, the viscosity decreases sharply.

[0065] The data in Table 4 show that, although the amount of crosslinked acrylate copolymer in all these compositions in Table 4 is constant (1.95% by weight), pH still affects viscosity.

[0066] In addition, additional compositions according to the invention (Example 2) and compositions other than those of the invention (Example B) were prepared and are shown in Tables 5 and 6 below.

[0067] Table 5: Example 2

[0068] Element weight% Sodium lauryl ether sulfate (70%) 13.5 Cocamidopropyl betaine (30%) 8.0 Myristic acid 3.0 Lauric acid 3.0 Potassium hydroxide (85%) 1 Crosslinked acrylate copolymer (30%) 6.5 glycerin 5.0 Propylene glycol 7.0 Phenoxyethanol 0.6 water Up to 100

[0069] The composition has a pH of about 6.8 and a viscosity of about 18450 cps (or mPa·s).

[0070] Table 6: Example B

[0071] Element weight% Sodium lauryl ether sulfate (70%) 13.5 Cocamidopropyl betaine (30%) 8.0 Myristic acid 3.0 Lauric acid 3.0 Potassium hydroxide (85%) 2 Crosslinked acrylate copolymer (30%) 6.5 glycerin 5.0 Propylene glycol 7.0 Phenoxyethanol 0.6 water Up to 100

[0072] The composition has a pH of about 7.8 and a viscosity of about 8390 cps (or mPa·s).

Claims

1. A makeup remover composition comprising (i) 1 to 25% by weight of synthetic surfactants; (ii) 0.1 to 10% by weight of free fatty acids; (iii) 0.1 to 2.5% by weight of a thickener, which is a cross-linked acrylate copolymer; (iv) 0.1 to 1% by weight of alkali; (iv) 40 to 70% by weight of water; The pH value of the composition is in the range of 6.2 to 6.8; and The viscosity of the composition is in the range of 15,000 to 35,000 mPa·s.

2. The composition according to claim 1, wherein the synthetic surfactant is selected from one or more of anionic, nonionic, and amphoteric surfactants.

3. The composition according to claim 2, wherein the anionic surfactant is sodium lauryl ether sulfate.

4. The composition according to claim 2 or 3, wherein the amphoteric surfactant is alkylamidopropyl betaine.

5. The composition according to any one of the preceding claims, comprising 5 to 15% by weight of a surfactant.

6. The composition according to any one of the preceding claims, comprising 0.1 to 6% by weight, preferably 4 to 6% by weight, of free fatty acids.

7. The composition according to any one of the preceding claims further comprises 0.1 to 20% by weight, preferably 5 to 15% by weight, of a moisturizer.

8. The composition according to any one of the preceding claims, wherein the base is potassium hydroxide, sodium hydroxide or triethanolamine, preferably potassium hydroxide.

9. The composition according to claim 8, comprising 0.4 to 0.6% by weight of potassium hydroxide.

10. The composition according to any one of the preceding claims, comprising up to 1% by weight of soap.

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