Cleansing cosmetics

Abstract

To provide wipe-off cosmetics that allow for easy removal without skin stress during wiping, and can remove aged keratin without skin irritation.SOLUTION: Wipe-off cosmetics comprise (A) a monoester of phosphoric acid and a higher alcohol with a linear structure, or salts thereof, (B) a basic compound, and (C) a monovalent higher alcohol with a linear structure, with the neutralization ratio of the component (B) to the acid value of the component (A) being 0.1 or more and 1.0 or less.EFFECT: This formulation allows for the restoration of the skin's original moisture and smoothness, and is expected to improve skin muddiness.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a cleansing cosmetic that can be removed without burdening the skin during removal and can remove aged keratin without causing skin irritation.

Background Art

[0002] In skin aging, in normal metabolism, a phenomenon often occurs where the stratum corneum (hereinafter referred to as aged keratin), which should become dirt and flake off, does not flake off but remains. This aged keratin is in a hard and dry state, and its moisturizing ability is also significantly reduced. In addition, aged keratin contains melanin pigments that should be excreted. Therefore, when aged keratin does not flake off but remains, the entire stratum corneum also becomes hard and thickened, the skin loses moisture and smoothness, and further changes to a dull appearance with a reduced sense of transparency.

[0003] From the above situation, it is considered that by removing aged keratin, the original moisture and smoothness of the skin can be restored, and dullness can be improved. A cosmetic for this purpose is a cleansing cosmetic. The usage method of the cleansing cosmetic is not limited, but generally, it is often used by applying it to a cosmetic tool such as cotton and wiping the skin.

[0004] Washing the face with a general facial cleanser aims to remove various dirt, mainly oil-soluble dirt such as sebum and makeup accumulated on the skin, by the action of the cleaning components. It is known that various skin components such as cholesterol and sebum are removed during face washing with this cleaning component (Non-Patent Document 1). In addition, it is known that cosmetics generally called cleansing and makeup remover are made for the purpose of removing makeup cosmetics, which are oily components, from the skin. On the other hand, different from general cleaning agents and cleansing, the cleansing cosmetic does not aim to remove oily dirt such as cholesterol and sebum, but has an action of removing water-soluble dirt, particularly aged keratin (Non-Patent Document 2).

[0005] Conventionally, alkaline cosmetics (Patent Document 1) have been known as cosmetics with exfoliating effects. Alkaline cosmetics contain basic substances such as potassium hydroxide and potassium carbonate, which enhance the penetration of water and water-soluble components into aging keratin, making it easier to remove aging keratin. However, alkaline cosmetics can cause skin irritation, raising safety concerns.

[0006] Another issue is that skin irritation can occur due to friction during the wiping process. Conventionally, natural polysaccharides such as xanthan gum and synthetic anionic compounds such as (acrylates / alkyl acrylate (C10-30)) crosspolymer have been incorporated as high-molecular-weight components in cosmetics to impart viscosity to the formulation and suppress skin irritation caused by friction. However, while the inclusion of high-molecular-weight components improves the glide of the cotton soaked in the wiping cosmetic, it also reduces the amount of dead skin cells that can be removed by physical contact with the cotton. In other words, there is a trade-off between the inclusion of high-molecular-weight components and the effectiveness of removing dead skin cells, so there has been a need for a technology that can reduce friction during the wiping process while still making it easier to remove dead skin cells. [Prior art documents] [Non-patent literature]

[0007] [Non-Patent Document 1] Fumio Hashimoto, Michiko Haruyama, Tokio Yamashita, Toshiaki Iso, Adsorption of surfactants to the skin and selective cleansing properties of facial cleansers, J.Soc.Cosmet.Chem.Japan.Vol.23,No.2 1989. [Non-Patent Document 2] Mai Horitsuji, Miho Morita, Akinori Inoue, Noritake Kitatani, Evaluation of the usefulness of wipe-off care, J.Soc.Cosmet.Chem.Japan.Vol.53, No.3 2019. [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 11-322570 [Disclosure of the Invention] [Problems that the invention aims to solve]

[0009] The object of this invention is to provide a wipe-off cosmetic that can remove aging keratin without burdening the skin during wiping and without causing skin irritation. [Means for solving the problem]

[0010] As a result of diligent research into the problem, the inventors have found a wipe-off cosmetic that can remove aging keratin without burdening the skin during wiping by combining (A) a monoester of phosphoric acid and a higher alcohol having a linear structure, or a salt thereof, (B) a basic compound, and (C) a monovalent higher alcohol having a linear structure, and by setting the degree of neutralization of (B) with respect to the acid value of (A) to 0.1 or more and 1.0 or less. [Effects of the Invention]

[0011] According to the present invention, aging keratin can be removed without putting a burden on the skin during wiping. This is expected to restore the skin's natural moisture and smoothness, and improve dullness. [Brief explanation of the drawing]

[0012] [Figure 1] Schematic diagram of artificial skin (Left: Part of a plan view, Right: Part of a side view) [Modes for carrying out the invention]

[0013] According to the present invention, a surfactant is formed by neutralizing (A) a monoester of a phosphoric acid and a higher alcohol having a linear structure, or a salt thereof, with (B) a basic compound, in a neutralization reaction where the degree of neutralization of (B) relative to the acid value of (A) is in the range of 0.1 to 1.0. This prevents the penetration of basic components into the skin and exhibits an excellent exfoliating effect while suppressing skin irritation. Furthermore, in addition to this surfactant, (C) oil-in-water emulsion particles prepared with a monovalent higher alcohol having a linear structure exhibit the effect of reducing physical friction during wiping.

[0014] The (A) used in the present invention is a monoester of phosphoric acid and a higher alcohol having a linear structure, or a salt thereof. (A) is not limited as long as it is used in ordinary cosmetics. (A) may be a monoester or a salt that has been partially neutralized in advance with a basic compound. Specific examples of monoesters include, for example, lauryl phosphate and cetyl phosphate. Specific examples of salts that have been partially neutralized in advance with a basic compound include, for example, sodium lauryl phosphate, disodium lauryl phosphate, potassium lauryl phosphate, potassium cetyl phosphate, and cetyl phosphate diethanolamine. The higher alcohol in (A) is preferably in a linear structure from the viewpoint of reducing friction during wiping and its exfoliating effect. The number of carbon atoms in the higher alcohol is not particularly limited, but 12 or more carbon atoms are preferred. Commercially available products include "Hostaphat CC100 (acid value: 250-400)" (Clariant), which contains cetyl phosphate, and "Hostaphat CK100 (acid value: 130-155)" (Clariant) and "AMPHISOL K (acid value: 130-155)" (DSM Nutrition), which contain potassium cetyl phosphate.

[0015] (A) used in the present invention can be used after measuring the acid value by an acid value measurement method in advance for the purpose of confirming the degree of neutralization. Alternatively, when using a commercially available product, the acid value described in the test report may be used. The acid value measurement method is not particularly limited. For example, in the Pharmaceutical Excipient Raw Material Standards 2021 issued by the Pharmaceutical and Life Hygiene Bureau, Pharmaceutical Review and Management Division, Ministry of Health, Labour and Welfare, a method of measuring the number of milligrams of potassium hydroxide (KOH: 56.11) required to neutralize 1 g of the sample can be used, and it can be calculated from Equation (1). The first method of this operation method is defined as follows. First method Except as otherwise specified, precisely weigh the amount of the sample specified in each article, place it in a 250 mL flask, add 50 mL of ethanol (95) or ethanol (95) / diethyl ether mixture (1:1) or ethanol (95) / diethyl ether mixture (2:1), warm to dissolve, and titrate with 0.1 mol / L potassium hydroxide solution while shaking occasionally. (Indicator: 1 mL of phenolphthalein test solution) However, the end point of the titration is the point where the light pink color of the solution persists for 30 seconds. Perform a blank test in the same manner for correction.

[0016]

Equation

[0017] In the present invention, the degree of neutralization calculated using 1 g equivalent of (B) with respect to the acid value of (A) measured in advance by the acid value measurement method is defined by Equation (2). In Equation (2), 1 g equivalent of (B) is the number obtained by dividing the mass per mole of the base by the valence of the base. For example, in the case of sodium hydroxide (NaOH: 40.00), the valence as a base is 1, so 1 g equivalent of sodium hydroxide is 40.00.

[0018]

Equation

[0019] The (A) used in the present invention can be used by one or in combination of two or more types. The amount of (A) used in the present invention is not particularly limited, but from the viewpoint of minimizing friction during wiping and the exfoliating effect, the content is preferably 0.1 to 3% by mass of the total amount of the composition, and more preferably 0.3 to 2% by mass.

[0020] The basic compound (B) used in the present invention is not particularly limited and can be appropriately selected depending on the purpose. Examples include alkali metal hydroxides, basic amino acids, and organic bases. Examples of alkali metal hydroxides include sodium hydroxide and potassium hydroxide. Examples of basic amino acids include lysine and arginine. Examples of organic bases include ammonium monoethanolamine, diethanolamine, triethanolamine, 2-amino-2-methyl-1-propanol, and 2-amino-2-hydroxymethyl-1,3-propanediol. From the viewpoint of safety in particular, basic amino acids and / or organic bases are preferred, and more specifically, arginine and 2-amino-2-methyl-1-propanol are preferred.

[0021] The amount of (B) used in this invention can be determined in advance using Equation 3, which is a modified version of Equation 2 based on the degree of neutralization. From the viewpoint of preventing the penetration of basic components into the skin and suppressing skin irritation while exhibiting an excellent exfoliating effect, the degree of neutralization is preferably 0.1 or more and 1.0 or less, and more preferably 0.3 or more and 0.8 or less. Within this range of the degree of neutralization, the amount of (B) calculated from Equation 3 is desirable.

[0022]

number

[0023] The (B) used in this invention can be used by one type or in combination of two or more types. When two or more types of (A) and (B) are combined, the degree of neutralization can be calculated from the information of multiple (A) and (B) using equation 4, which is an extension of equation 2.

[0024]

number

[0025] Let's look at a specific example using equation 4. If the acid value of potassium cetyl phosphate (A1) is 143 and its mass percentage is 0.8%, the acid value of potassium lauryl phosphate (A2) is 125 and its mass percentage is 0.2%, the 1g equivalent of arginine (B1) is 174.2 and its mass percentage is 0.22%, and the 1g equivalent of 2-amino-2-methyl-1-propanol (B2) is 89.14 and its mass percentage is 0.1%, then the degree of neutralization can be calculated from equation 4 as 0.960.

[0026] Substitution example for <Number 4> JPEG0007862920000005.jpg38148

[0027] The number of carbon atoms in the (C) monovalent higher alcohol having a linear structure used in the present invention is not particularly limited, but monovalent linear saturated alcohols having 16 to 22 carbon atoms are preferred. Examples include cetyl alcohol, stearyl alcohol, and behenyl alcohol.

[0028] The (C) used in the present invention can be used by one or in combination of two or more types. The amount of (C) used in the present invention is not particularly limited, but from the viewpoint of forming oil-in-water emulsion particles and exhibiting the effect of reducing physical friction during wiping, the content is preferably 0.1 to 6% by mass of the total amount of the composition, and more preferably 0.5 to 4% by mass.

[0029] In addition to the essential components mentioned above, the cleansing cosmetic composition of the present invention may also contain, as necessary, water, surfactants, polyhydric alcohols, lower alcohols, thickeners, water-soluble polymers, preservatives, chelating agents, medicinal ingredients, oils, silicones, antioxidants, UV absorbers, fragrances, pigments, and other components not commonly used in cosmetics, within qualitative and quantitative limits that do not impair the effects of the present invention.

[0030] The method of using the wipe-off cosmetic composition of the present invention is not particularly limited, but one method of use is to apply it to a cosmetic tool such as a cotton pad and wipe the skin with it. For this reason, it is preferable that the wipe-off cosmetic composition of the present invention be in liquid form so that it can be applied to a cosmetic tool. [Examples]

[0031] The present invention will be further explained below with reference to examples. These examples do not limit the present invention in any way. The amounts are expressed as mass% relative to the total amount of the composition.

[0032] For the examples and comparative examples, efficacy tests were conducted using the wipe-off cosmetic formulations shown in Table 1 below. [Manufacturing method for wipe-off cosmetics] Components A, C, and other oily components in the table were heated and dissolved at 80°C. These were then mixed with component B and other aqueous components, which were similarly heated and dissolved at 80°C. After treatment with a homomoxer, the mixture was cooled to room temperature to prepare the sample. Components A' and C'1 in the table were added in accordance with the same procedures as components A and C, respectively. Component C'2 was added after being mixed with the aqueous component.

[0033] (Low friction when wiping) [Evaluation Method] The coefficient of static friction (μS) was measured using a surface texture measuring instrument (Shinto Kagaku Co., Ltd.: TYPE-14) with the cosmetic materials prepared in the examples and comparative examples. A circular piece of cotton (Pure Touch Cotton: Naris Cosmetics Co., Ltd.: 310g / m²) with a diameter of 30mm was placed on an artificial skin holder with a radius of R50mm that mimicked the curvature of a finger. 2 A cotton ball was placed between two pieces of material, and 1.5 ml of cosmetic solution was dropped onto it. This holder was then attached to the arm of the measuring instrument, and a 50 g weight was placed on top as a horizontal load. The artificial skin described below was placed on the moving platform of the measuring instrument. The static friction coefficient was measured at a moving speed of 3,000 mm / min. [Evaluation Criteria] The static friction coefficient was divided into four levels and used as an evaluation value. These four levels represent a range where differences can be clearly perceived through sensory evaluation by expert panelists. ◎: Less than 1.3 (Very low friction on the skin, excellent) ○: 1.3 or higher to less than 1.4 (less friction on the skin, excellent) △: 1.4 or higher but less than 1.5 (friction against the skin is felt) ×: 1.5 or higher (high friction on the skin)

[0034] Figure 1 is a schematic diagram of the artificial skin used for the measurement. Artificial skin with a pattern of skin furrows and ridges was fabricated on a 50mm x 90mm x 10mm flat plate using a 3D printer with UV-curable acrylic resin. The artificial skin has a pattern as shown on the left side of the figure, and each pattern was fabricated to be a square with sides of 0.6mm, with a skin furrow width of 0.15mm (the cross-section is roughly rectangular with a slightly narrower base) and a skin furrow depth of 0.025mm.

[0035] (Exfoliating effect) [Evaluation Method] The amount of aged keratin removed during wiping was confirmed by protein quantification using the cosmetic formulations prepared in the examples and comparative examples. One mL of lotion was applied to a cotton pad, and a 5 cm x 14 cm area was wiped 20 times in a consistent direction on the back of a person who had been washed with warm water. The wiping was performed with consistent pressure. The wiped cotton pads were placed in a tube, 1.5 mL of 8M urea was added, and the tubes were incubated overnight at 37°C to extract the protein. The extract was squeezed out with a syringe, the sample solution was collected, and protein quantification was performed using the BCA method to measure the amount of protein removed. 40 μL of the collected sample solution was added to a 96-cell culture cluster. Reagent A (1% bicinchoninic acid, 2% Na2CO3, 0.16% tartaric acid, 0.4% NaOH, 0.95% NaHCO3 aqueous solution) and Reagent B (4% CuSO4·5H2O aqueous solution) were mixed in a 50:1 ratio and added in 200 μL portions. After incubation at 37°C for 30 minutes, the absorbance at 540 nm was measured. Simultaneously, a calibration curve was created by diluting bovine blood albumin (BSA) three times, starting from a concentration of 0.4 mg / mL and diluting it 2-fold each time. Protein solubility was calculated from this calibration curve. Using this method, a higher value indicates a greater amount of protein removed, and therefore a higher effectiveness in removing aged keratin. [Evaluation Criteria] The protein quantification results were divided into four levels and used as evaluation values. ◎: 0.28mg or more (Particularly effective at removing aging dead skin cells, extremely superior) ○: 0.24mg or more to less than 0.28mg (high effectiveness in removing aging keratin) △: 0.20mg or more but less than 0.24mg (almost no effect on removing aging keratin) ×: Less than 0.20mg (No effect on removing aging dead skin cells)

[0036] (skin irritation) [Evaluation Method] Using the lotions prepared according to the example formulation and the comparative example formulation, 10 monitors who had previously experienced skin problems with cleansing cosmetics used the products for one week. A questionnaire was administered regarding the presence or absence of skin problems such as itching and redness, and the safety of the products was evaluated. [Safety Evaluation Criteria] ○: Out of 10 participants, 0 reported experiencing skin problems. △: 1 to 2 out of 10 participants reported experiencing skin problems. ×: More than 3 out of 10 participants reported experiencing skin problems.

[0037] [Table 1]

[0038] According to Table 1, in Examples 1-5, the oil-in-water emulsion particles formed with (C) and a surfactant neutralized in a neutralization reaction between (A) and (B) in a range of 0.1 to 1.0 in relation to the acid value of (A) prevented the penetration of basic components into the skin, suppressed skin irritation, while exhibiting excellent exfoliation effects and reducing physical friction during wiping. In Examples 6 and 7, it was confirmed that similar effects could be obtained even when the types of (A), (B), and (C) were changed. Furthermore, it was confirmed that similar effects could be obtained in Example 8 when two types of (B) were used, and in Example 9 when two types of (A) and two types of (B) were used. On the other hand, in Comparative Example 1, the degree of neutralization of (B) relative to the acid value of (A) was 0.1 or less, and a sufficient exfoliating effect was not obtained. In Comparative Example 2, the degree of neutralization of (B) relative to the acid value of (A) was 1.0 or more, suggesting that the basic component penetrated the skin and induced skin irritation. In Comparative Example 3, instead of component (A), an anionic surfactant with a structure similar to component (A), consisting of a fatty acid with an alkyl group and glutamic acid, was used. However, the prepared oil-in-water emulsion particles were unstable, and the oil and water separated after 24 hours of preparation, so it did not show an effect of reducing physical friction during wiping. In Comparative Example 4, a nonionic surfactant with an acid value of 1 or less was used. The prepared oil-in-water emulsion particles were in good condition, but it did not show an effect of reducing physical friction during wiping. Furthermore, since this nonionic surfactant lacks a functional group to neutralize basic compounds, the basic component induced skin irritation. Comparative Example 5 used a monohydric higher alcohol with a branched structure instead of component (C). The oil-in-water emulsion particles prepared in the same manner as in Comparative Example 3 were unstable and did not show an effect of reducing physical friction during wiping. Comparative Example 6 used a polymer component instead of component (C). It showed an effect of reducing physical friction during wiping, but it was confirmed that the exfoliation effect was inhibited.

[0039] The results in Table 1 show that the wipe-off cosmetic composition of the example achieved both reduced friction on the skin and the effect of removing aged keratin without causing skin irritation. By using the present invention, it is possible to provide a wipe-off cosmetic composition that can be wiped off without burdening the skin and can remove aged keratin without causing skin irritation.

[0040] The compositions for each formulation were prepared using conventional methods. It was confirmed that all formulations exhibited the effects of the present invention.

[0041] (1) Wipe-off gel: Example formulation 1 Ingredient name Amount (%) Cetyl phosphate 3 2-amino-2-hydroxymethyl-1,3-propanediol 0.7 Behenyl alcohol 6 Hydroxypropyl methylcellulose 0.05 Polyethylene glycol (average molecular weight: 1540) 1 Methylphenylpolysiloxane 2 1,3-Butylene glycol 8 Preservative (appropriate amount) Purified water residue Total 100 Neutralization degree: 0.997

[0042] (2) Toner for wiping off: Formula example 2 Ingredient Name | Amount (%) | Potassium Cetyl Phosphate | 1 Sodium hydroxide 0.05 Cetanol 0.5 1,3-Butylene glycol 8 Glycerin 4 Glyceryl tri-2-ethylhexanoate 0.2 PEG-50 Hydrogenated Castor Oil 0.5 PPG-6 Decyltetradeceth-30 0.5 Sodium carbonate 0.025 Sodium bicarbonate 0.05 Preservative (appropriate amount) Purified water residue Total 100 Degree of neutralization: 0.490

[0043] (3) Wipe-off serum: Formula example 3 Ingredient name Amount (%) Lauryl phosphate (acid value: 400) 0.1 Arginine 0.05 Potassium hydroxide 0.02 Stearyl alcohol 1 1,3-Butylene glycol 5 Polysorbate 20 1 Sodium hyaluronate 0.05 Carboxyvinyl polymer 0.01 Ethanol 5 Disodium edetate (appropriate amount) Preservative (appropriate amount) Purified water residue Total 100 Degree of neutralization: 0.903 [Industrial applicability]

[0044] By using the present invention, it is possible to provide a wipe-off cosmetic that removes aging keratin without burdening the skin during wiping and without causing skin irritation.

Claims

1. (A) Monoesters of phosphoric acid and higher alcohols having a linear structure, or salts thereof. (B) Basic compounds (C) Monovalent higher alcohols having a linear structure An oil-in-water type wipe-off cosmetic composition characterized by containing (A) and having a degree of neutralization of (B) relative to the acid value of (A) of 0.1 or more and 1.0 or less.

2. (B) The oil-in-water type wipe-off cosmetic composition according to claim 1, wherein the basic compound is a basic amino acid and / or an organic base.

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