Skin cleansing composition and skin cleansing method

Abstract

To provide a skin cleansing composition excellent in foaming while using a cleansing component different from a fatty acid salt, and a skin cleansing method using the skin cleansing composition.SOLUTION: This skin cleansing composition is obtained by formulating a polyoxyethylene alkyl ether carboxylic acid or its salt with one or more kinds selected from an acylmethyltaurine or its salt, an acylmethylalanine or its salt and an acylglutamic acid or its salt. The skin cleaning method uses the skin cleaning composition.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a skin cleansing composition and a skin cleansing method. [Background technology]

[0002] Skin cleansing compositions contain various ingredients to achieve the desired effects.

[0003] As an example of a skin cleansing composition, Patent Document 1 discloses a skin cleansing composition characterized by containing (A) a fatty acid salt having 12 to 18 carbon atoms, (B) a low-molecular-weight oil gelling agent, and (C) a dihydric alcohol. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-034923 Summary of the Invention [Problem to be solved by the invention]

[0005] Skin cleansing compositions generally contain fatty acid salts as skin cleansing ingredients, as shown in Patent Document 1. However, although skin cleansing compositions containing fatty acid salts foam well, they can sometimes leave the skin feeling less moisturized (as if the skin is dry) or feeling tight after washing.

[0006] Therefore, studies have been conducted to improve the feel of skin after washing by using skin cleansing compositions that contain cleansing ingredients other than fatty acid salts. However, such skin cleansing compositions have sometimes exhibited poor foaming properties during use. Therefore, there is a demand for skin cleansing compositions that contain cleansing ingredients other than fatty acid salts and yet exhibit excellent foaming properties.

[0007] In view of the above circumstances, an object of the present invention is to provide a skin cleansing composition that has excellent foaming properties while using cleansing ingredients other than fatty acid salts. Another object of the present invention is to provide a skin cleansing method using the skin cleansing composition. [Means for solving the problem]

[0008] As a result of extensive research, the present inventors have found that a skin cleansing composition containing a polyoxyethylene alkyl ether carboxylic acid or a salt thereof in combination with one or more selected from acylmethyltaurine or a salt thereof, acylmethylalanine or a salt thereof, and acylglutamic acid or a salt thereof can have excellent foaming properties despite using cleansing components other than fatty acid salts. Based on this finding, the present invention has been completed.

[0009] The present invention includes the following inventions [1] to [6].

[0010] The skin cleansing composition [1] contains a polyoxyethylene alkyl ether carboxylic acid or a salt thereof, and one or more selected from acylmethyltaurine or a salt thereof, acylmethylalanine or a salt thereof, and acylglutamic acid or a salt thereof.

[0011] The skin cleansing composition of [2] is the skin cleansing composition of [1], which contains α-olefin sulfonic acid or a salt thereof.

[0012] The skin cleansing composition of [3] is the skin cleansing composition of [1] or [2], wherein the one or more selected from acylmethyltaurine or a salt thereof, acylmethylalanine or a salt thereof, and acylglutamic acid or a salt thereof are blended with one or more selected from acylmethyltaurine or a salt thereof, and acylmethylalanine or a salt thereof.

[0013] The skin cleansing composition [4] is any one of the skin cleansing compositions selected from the skin cleansing compositions [1] to [3], and contains a diester of malic acid and a monohydric alcohol.

[0014] The skin cleansing composition [5] is any one of the skin cleansing compositions selected from the skin cleansing compositions [1] to [4], wherein the polyoxyethylene alkyl ether carboxylic acid or its salt is a polyoxyethylene alkyl ether carboxylic acid or its salt having an average number of moles of oxyethylene added of 10 or less.

[0015] The skin cleansing method [6] is a skin cleansing method using any one of the skin cleansing compositions [1] to [5]. [Effects of the Invention]

[0016] The skin cleansing composition according to the present invention can provide a skin cleansing composition with excellent foaming properties, and the skin cleansing method according to the present invention can provide a skin cleansing method using the skin cleansing composition with excellent foaming properties. DETAILED DESCRIPTION OF THE INVENTION

[0017] The present invention will be described below based on an embodiment of the present invention (hereinafter referred to as "the present embodiment").

[0018] <Skin cleansing composition> The skin cleansing composition of this embodiment contains a polyoxyethylene alkyl ether carboxylic acid or a salt thereof, and one or more selected from acylmethyltaurine or a salt thereof, acylmethylalanine or a salt thereof, and acylglutamic acid or a salt thereof. The skin cleansing composition of this embodiment has excellent foaming properties due to the blending of a combination of a polyoxyethylene alkyl ether carboxylic acid or a salt thereof and one or more selected from acylmethyltaurine or a salt thereof, acylmethylalanine or a salt thereof, and acylglutamic acid or a salt thereof.

[0019] (Polyoxyethylene alkyl ether carboxylic acid or its salt) The skin cleansing composition of the present embodiment contains one or more polyoxyethylene alkyl ether carboxylic acids or salts thereof.

[0020] As the polyoxyethylene alkyl ether carboxylic acid or a salt thereof, for example, one represented by the following formula (1) can be used. R a -O-(CH2CH2O)n-CH2-COOX a (1) (R a represents a hydrocarbon group having 12 to 24 carbon atoms. The hydrocarbon group having 12 to 24 carbon atoms may be linear or branched, and may be saturated or unsaturated. X a represents hydrogen, an alkali metal, an alkaline earth metal, ammonium, an alkanolamine, or a basic amino acid. n represents the average number of moles of oxyethylene added and is 0.5 to 20.

[0021] The skin cleansing composition of this embodiment may contain either a polyoxyethylene alkyl ether carboxylic acid or a salt of a polyoxyethylene alkyl ether carboxylic acid as the polyoxyethylene alkyl ether carboxylic acid or its salt, or may contain a combination of a polyoxyethylene alkyl ether carboxylic acid and a salt of a polyoxyethylene alkyl ether carboxylic acid.

[0022] Examples of the "salt" in the salt of polyoxyethylene alkyl ether carboxylic acid blended in the skin cleansing composition of this embodiment include alkali metals, alkaline earth metals, ammonium, alkanolamines, and basic amino acids.

[0023] Examples of polyoxyethylene alkyl ether carboxylic acids or salts thereof that can be incorporated into the skin cleansing composition of this embodiment include polyoxyethylene lauryl ether carboxylic acids or salts thereof having an average number of moles of oxyethylene added of 2 to 20 (such as polyoxyethylene lauryl ether sodium acetate (3 EO), polyoxyethylene lauryl ether sodium acetate (4.5 EO), and polyoxyethylene lauryl ether sodium acetate (10 EO)), polyoxyethylene tridecyl ether carboxylic acids or salts thereof having an average number of moles of oxyethylene added of 2 to 20, polyoxyethylene myristyl ether carboxylic acids or salts thereof having an average number of moles of oxyethylene added of 2 to 20, and polyoxyethylene cetyl ether carboxylic acids or salts thereof having an average number of moles of oxyethylene added of 2 to 20.

[0024] The skin cleansing composition of this embodiment may use, as the polyoxyethylene alkyl ether carboxylic acid or its salt, for example, a polyoxyethylene alkyl ether carboxylic acid or its salt having an average number of moles of oxyethylene added of 10 or less.

[0025] In the skin cleansing composition of this embodiment, it is preferable to use, as the polyoxyethylene alkyl ether carboxylic acid or salt thereof, a polyoxyethylene alkyl ether carboxylic acid or salt thereof having an average number of moles of oxyethylene added of 6 or less, from the viewpoint of superior foaming.

[0026] In order to provide excellent moisturizing feeling, smoothness, and non-stickiness to the skin after washing, the skin cleansing composition of this embodiment is preferably a polyoxyethylene alkyl ether carboxylic acid or a salt thereof having an average number of moles of oxyethylene added of 6 or more. Here, "skin after washing" refers to dry skin after washing with the skin cleansing composition of this embodiment (this meaning will be used in the following description).

[0027] The polyoxyethylene alkyl ether carboxylic acid or a salt thereof blended in the skin cleansing composition of this embodiment may be, for example, laureth-3 carboxylic acid, potassium laureth-3 carboxylic acid, sodium laureth-3 carboxylic acid, laureth-3 carboxylic acid TIPA, laureth-4 carboxylic acid, potassium laureth-4 carboxylic acid, sodium laureth-4 carboxylic acid, potassium laureth-4.5 acetic acid, laureth-5 carboxylic acid, potassium laureth-5 carboxylic acid, sodium laureth-5 carboxylic acid, laureth-6 carboxylic acid, potassium laureth-6 carboxylic acid, sodium laureth-6 carboxylic acid, laureth-8 carboxylic acid, sodium laureth-8 carboxylic acid, laureth-10 carboxylic acid, potassium laureth-10 carboxylic acid, laureth-11 carboxylic acid, sodium laureth-11 carboxylic acid, laureth-12 carboxylic acid, sodium laureth-12 carboxylic acid, laureth-13 carboxylic acid, laureth-13 carboxylic acid Examples of suitable carboxylic acids include sodium laureth-14 carboxylic acid, sodium laureth-14 carboxylate, sodium laureth-16 carboxylate, laureth-17 carboxylic acid, sodium laureth-17 carboxylate, trideceth-3 carboxylic acid, potassium trideceth-3 carboxylate, sodium trideceth-3 carboxylate, trideceth-4 carboxylic acid, potassium trideceth-4 carboxylate, sodium trideceth-4 carboxylate, sodium trideceth-6 carboxylate, trideceth-7 carboxylic acid, potassium trideceth-7 carboxylate, sodium trideceth-7 carboxylate, trideceth-8 carboxylic acid, sodium trideceth-8 carboxylate, sodium trideceth-12 carboxylate, trideceth-15 carboxylic acid, sodium trideceth-15 carvone, potassium trideceth-15 carvone, trideceth-19 carboxylic acid, potassium trideceth-19 carboxylate, sodium trideceth-19 carboxylate, myreth-3 carboxylic acid, myreth-5 carboxylic acid, and sodium ceteth-13 carboxylate.

[0028] The amount of polyoxyethylene alkyl ether carboxylic acid or a salt thereof blended in the skin cleansing composition of the present embodiment is not particularly limited and can be set appropriately.

[0029] The amount of polyoxyethylene alkyl ether carboxylic acid or a salt thereof in the skin cleansing composition of this embodiment is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more, from the viewpoint of superior foaming.

[0030] The amount of polyoxyethylene alkyl ether carboxylic acid or its salt in the skin cleansing composition of this embodiment is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less, from the viewpoint of reducing the risk of skin irritation.

[0031] From the above-mentioned viewpoints, the range of the blending amount of polyoxyethylene alkyl ether carboxylic acid or its salt in the skin cleansing composition of this embodiment is preferably 0.1% by mass or more and 20% by mass or less, more preferably 0.5% by mass or more and 15% by mass or less, and even more preferably 1% by mass or more and 10% by mass or less.

[0032] (One or more selected from acylmethyltaurine or its salt, acylmethylalanine or its salt, and acylglutamic acid or its salt) The skin cleansing composition of this embodiment contains one or more selected from acylmethyltaurine or a salt thereof, acylmethylalanine or a salt thereof, and acylglutamic acid or a salt thereof. In the following description, the "one or more selected from acylmethyltaurine or a salt thereof, acylmethylalanine or a salt thereof, and acylglutamic acid or a salt thereof" contained in the skin cleansing composition of this embodiment may be collectively referred to as "acylmethyltaurine, etc."

[0033] As the acylmethyltaurine or the like to be blended in the skin cleansing composition of this embodiment, acylmethylalanine or a salt thereof is preferred from the viewpoint of excellent foaming properties.

[0034] As the acylmethyltaurine or the like to be blended in the skin cleansing composition of this embodiment, from the viewpoint of providing better moisturizing feeling, smoothness, and non-stickiness to the skin after washing, either acylmethyltaurine or a salt thereof, or acylglutamic acid or a salt thereof is preferred, and acylmethyltaurine or a salt thereof is more preferred.

[0035] (Acylmethyltaurine or its salt) The skin cleansing composition of the present embodiment contains one or more types of acylmethyltaurine or salts thereof as the acylmethyltaurine or the like.

[0036] As the acylmethyltaurine or a salt thereof, for example, one represented by the following formula (2) can be used. R b -CO-N(CH3)-CH2CH2SO3X b (2) (R b represents a hydrocarbon group having 7 to 24 carbon atoms. The hydrocarbon group having 7 to 24 carbon atoms may be linear or branched, and may be saturated or unsaturated. X b represents hydrogen, an alkali metal, an alkaline earth metal, ammonium, an alkanolamine, an amino acid, or taurine or a salt thereof (such as sodium taurate).

[0037] The skin cleansing composition of the present embodiment may contain either acylmethyltaurine or a salt of acylmethyltaurine as the acylmethyltaurine or its salt, or may contain a combination of acylmethyltaurine and a salt of acylmethyltaurine.

[0038] Examples of the "salt" in the salt of acylmethyltaurine blended in the skin cleansing composition of this embodiment include alkali metal salts (sodium salt, potassium salt, etc.), alkaline earth metal salts, ammonium salts, alkanolamine salts, and amino acid salts.

[0039] Examples of the acyl methyl taurine or a salt thereof that can be incorporated into the skin cleansing composition of this embodiment include caproyl methyl taurine or a salt thereof, lauroyl methyl taurine or a salt thereof, coconut oil fatty acid methyl taurine or a salt thereof, myristoyl methyl taurine or a salt thereof, palmitoyl methyl taurine or a salt thereof, stearoyl methyl taurine or a salt thereof, and oleoyl methyl taurine or a salt thereof.

[0040] Examples of the acyl methyl taurine or salts thereof blended in the skin cleansing composition of this embodiment include, as ingredient names in cosmetics, sodium caproyl methyl taurine, sodium lauroyl methyl taurine, potassium cocoyl methyl taurine, magnesium cocoyl methyl taurine, sodium cocoyl methyl taurine, sodium cocoyl methyl taurine taurine, sodium myristoyl methyl taurine, sodium palmitoyl methyl taurine, sodium stearoyl methyl taurine, and sodium oleoyl methyl taurine.

[0041] (Acylmethylalanine or its salt) The skin cleansing composition of this embodiment contains one or more types of acylmethylalanine or salts thereof as the acylmethyltaurine or the like.

[0042] As the acylmethylalanine or a salt thereof, for example, one represented by the following formula (3) can be used. R c -CO-N(CH3)-CH2CH2-COOX c (3) (R c represents a hydrocarbon group having 7 to 24 carbon atoms. The hydrocarbon group having 7 to 24 carbon atoms may be linear or branched, and may be saturated or unsaturated. X c represents hydrogen, an alkali metal, an alkaline earth metal, ammonium, an alkanolamine, or an amino acid.

[0043] The skin cleansing composition of the present embodiment may contain either acylmethylalanine or a salt of acylmethylalanine as the acylmethylalanine or its salt, or may contain a combination of acylmethylalanine and a salt of acylmethylalanine.

[0044] Examples of the "salt" in the salt of acylmethylalanine blended in the skin cleansing composition of this embodiment include alkali metals, alkaline earth metals, ammonium, alkanolamines, and basic amino acids.

[0045] Examples of the acylmethylalanine or a salt thereof that can be incorporated into the skin cleansing composition of this embodiment include lauroylmethylalanine or a salt thereof (such as sodium lauroylmethyl-β-alanine), cocoylmethylalanine or a salt thereof, and myristoylmethylalanine or a salt thereof.

[0046] Examples of acylmethylalanine salts that can be incorporated into the skin cleansing composition of this embodiment include alkali metal salts (sodium salt, potassium salt, etc.), alkaline earth metal salts, ammonium salts, alkanolamine salts, and amino acid salts.

[0047] Examples of the acylmethylalanine or salts thereof blended in the skin cleansing composition of this embodiment include, as ingredient names in cosmetics, lauroylmethylalanine, lauroylmethylalanine K, lauroylmethylalanine Na, lauroylmethylalanine TEA, cocoylmethylalanine, cocoylmethylalanine Na, myristoylmethylalanine, and myristoylmethylalanine Na.

[0048] (Acylglutamic acid or its salt) The skin cleansing composition of this embodiment contains one or more types of acylglutamic acid or salts thereof as the acylmethyltaurine or the like.

[0049] The acylglutamic acid or a salt thereof that can be incorporated into the skin cleansing composition of this embodiment may be, for example, one represented by the following formula (4). R d -CO-NH-CH(COOX d )-CH2CH2-COOX e (4) (R d represents a hydrocarbon group having 7 to 24 carbon atoms. The hydrocarbon group having 7 to 24 carbon atoms may be linear or branched, and may be saturated or unsaturated. X d , X e represents hydrogen, an alkali metal, an alkaline earth metal, ammonium, an alkanolamine, or an amino acid. d , X e may be the same or different.)

[0050] The skin cleansing composition of this embodiment may contain either acylglutamic acid or a salt of acylglutamic acid as the acylglutamic acid or its salt, or may contain a combination of acylglutamic acid and a salt of acylglutamic acid.

[0051] Examples of the "salt" in the salt of acylglutamic acid blended in the skin cleansing composition of this embodiment include alkali metal salts (monosodium salt, disodium salt, monopotassium salt, dipotassium salt, etc.), alkaline earth metal salts, ammonium salts, alkanolamine salts, and amino acid salts.

[0052] Examples of acyl glutamic acid or a salt thereof that can be incorporated into the skin cleansing composition of this embodiment include caproyl glutamic acid or a salt thereof, lauroyl glutamic acid or a salt thereof, cocoyl glutamic acid or a salt thereof (e.g., sodium N-coconut oil fatty acid acyl-L-glutamate), myristoyl glutamic acid or a salt thereof, palmitoyl glutamic acid or a salt thereof, and stearoyl methyl glutamic acid or a salt thereof.

[0053] Examples of acyl glutamic acid or salts thereof incorporated into the skin cleansing composition of this embodiment include, as ingredient names in cosmetics, disodium capryloyl glutamate, lauroyl glutamic acid, disodium lauroyl glutamate, potassium lauroyl glutamate, sodium lauroyl glutamate, TEA lauroyl glutamate, cocoyl glutamic acid, disodium cocoyl glutamate, potassium cocoyl glutamate, sodium cocoyl glutamate, TEA cocoyl glutamate, myristoyl glutamic acid, potassium myristoyl glutamate, sodium myristoyl glutamate, magnesium palmitoyl glutamate, stearoyl glutamic acid, disodium stearoyl glutamate, aluminum stearoyl glutamate, potassium stearoyl glutamate, sodium stearoyl glutamate, sodium palm fatty acid glutamate, and sodium olive oil fatty acid glutamate.

[0054] In order to provide superior smoothness to the skin after washing, the skin cleansing composition of this embodiment preferably contains cocoyl glutamic acid or a salt thereof as the acyl acyl glutamic acid or a salt thereof.

[0055] The amount of acylmethyltaurine and the like to be blended in the skin cleansing composition of this embodiment is not particularly limited and can be set as appropriate.

[0056] The blending amount of acylmethyltaurine etc. in the skin cleansing composition of this embodiment is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more, from the viewpoint of superior foaming.

[0057] The amount of acylmethyltaurine and the like in the skin cleansing composition of this embodiment is preferably 15% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less, from the viewpoint of achieving better non-stickiness on the skin after washing.

[0058] From the above-mentioned viewpoints, the blending amount of acylmethyltaurine, etc. in the skin cleansing composition of this embodiment is preferably 0.1% by mass or more and 15% by mass or less, more preferably 0.5% by mass or more and 10% by mass or less, and even more preferably 1% by mass or more and 5% by mass or less.

[0059] (mass ratio: polyoxyethylene alkyl ether carboxylic acid or its salt / acylmethyl taurine, etc.) In the skin cleansing composition of this embodiment, the mass ratio of the amount of polyoxyethylene alkyl ether carboxylic acid or a salt thereof to the amount of acylmethyltaurine, etc. (polyoxyethylene alkyl ether carboxylic acid or a salt thereof / acylmethyltaurine, etc.) is not particularly limited, but is, for example, 0.5 or more and 10 or less.

[0060] (optional ingredient) The skin cleansing composition of this embodiment may contain ingredients (hereinafter referred to as "optional ingredients") other than the above-mentioned polyoxyethylene alkyl ether carboxylic acid or a salt thereof, acylmethyl taurine, etc. The optional ingredients may be known ingredients used in skin cleansing compositions, and examples thereof include water, anionic surfactants (excluding polyoxyethylene alkyl ether carboxylic acid or a salt thereof, acylmethyl taurine, etc.), cationic surfactants, amphoteric surfactants, monohydric alcohols, polyhydric alcohols, sugars, esters (such as diesters of malic acid and monohydric alcohols), oils and fats, hydrocarbons, waxes, silicones, polymeric compounds (such as cationic polymers and amphoteric polymers), amino acids, animal and plant extracts, substances derived from microorganisms, inorganic compounds, fragrances, preservatives, sequestering agents, and ultraviolet absorbers.

[0061] (water) The skin cleansing composition of this embodiment preferably contains water, from the viewpoint of facilitating the incorporation of polyoxyethylene alkyl ether carboxylic acid or a salt thereof, acylmethyl taurine, etc. The amount of water to be incorporated is not particularly limited and may be set appropriately, but is, for example, 65% by mass or more and 85% by mass or less.

[0062] (α-olefin sulfonic acid or its salt) From the viewpoint of achieving superior foaming, the skin cleansing composition of this embodiment preferably contains one or more types of α-olefin sulfonic acid or salts thereof.

[0063] The α-olefin sulfonic acid or a salt thereof blended in the skin cleansing composition of this embodiment may be, for example, an alkylsulfonic acid or a salt thereof in which an α-olefin having from 10 to 20 carbon atoms is sulfonated. Furthermore, examples of the "salt" in the salt of α-olefin sulfonic acid include sodium salt, potassium salt, and triethanolamine salt.

[0064] The skin cleansing composition of this embodiment may contain either α-olefin sulfonic acid or a salt of α-olefin sulfonic acid as the α-olefin sulfonic acid or its salt, or may contain a combination of α-olefin sulfonic acid and a salt of α-olefin sulfonic acid.

[0065] Examples of the α-olefin sulfonic acid or a salt thereof that can be incorporated into the skin cleansing composition of this embodiment include sodium tetradecene sulfonate.

[0066] Examples of the α-olefin sulfonic acid or salts thereof blended in the skin cleansing composition of this embodiment include, as ingredient names in cosmetics, sodium olefin (C12-14) sulfonate, sodium olefin (C14-16) sulfonate, sodium olefin (C14-18) sulfonate, sodium olefin (C16-18) sulfonate, and sodium olefin C16 sulfonate.

[0067] The amount of α-olefin sulfonic acid or a salt thereof blended in the skin cleansing composition of this embodiment is not particularly limited and can be set appropriately.

[0068] The amount of α-olefin sulfonic acid or a salt thereof in the skin cleansing composition of this embodiment is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more, from the viewpoint of superior foaming.

[0069] The amount of α-olefin sulfonic acid or its salt in the skin cleansing composition of this embodiment is preferably 15% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less, from the viewpoint of reducing the risk of skin irritation.

[0070] From the above-mentioned viewpoints, the amount of α-olefin sulfonic acid or its salt in the skin cleansing composition of this embodiment is preferably 0.1% by mass or more and 15% by mass or less, more preferably 0.5% by mass or more and 10% by mass or less, and even more preferably 1% by mass or more and 5% by mass or less.

[0071] (mass ratio: (polyoxyethylene alkyl ether carboxylic acid or its salt + acylmethyl taurine, etc.) / α-olefin sulfonic acid or its salt) In the skin cleansing composition of this embodiment, the mass ratio of the total amount of polyoxyethylene alkyl ether carboxylic acid or its salt and acylmethyl taurine, etc. to the amount of α-olefin sulfonic acid or its salt ((polyoxyethylene alkyl ether carboxylic acid or its salt + acylmethyl taurine, etc.) / α-olefin sulfonic acid or its salt) is not particularly limited, but is, for example, 0.5 or more and 10 or less.

[0072] (diester of malic acid and monohydric alcohol) The skin cleansing composition of this embodiment may contain one or more diesters of malic acid and a monohydric alcohol. From the viewpoint of providing a more excellent moisturizing feeling and smoothness to the skin after washing, the skin cleansing composition of this embodiment preferably contains a diester of malic acid and a monohydric alcohol.

[0073] The "monohydric alcohol" in the diester of malic acid and a monohydric alcohol includes, for example, a monohydric alcohol having a hydrocarbon group with 12 to 24 carbon atoms. The hydrocarbon group with 12 to 24 carbon atoms may be linear or branched, and may be saturated or unsaturated.

[0074] The diester of malic acid and a monohydric alcohol blended in the skin cleansing composition of this embodiment may have a molecular weight of 800 or less. The diester of malic acid and a monohydric alcohol may be liquid at 25°C. "Liquid at 25°C" means that the diester has fluidity when left standing at 25°C.

[0075] Examples of the diester of malic acid and a monohydric alcohol blended in the skin cleansing composition of this embodiment include, as ingredient names in cosmetics, dialkyl (C12,13) ​​malate, diisostearyl malate, diethylhexyl malate, and dioctyldodecyl malate.

[0076] The amount of the diester of malic acid and a monohydric alcohol in the skin cleansing composition of this embodiment is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more, from the viewpoint of providing a more excellent moisturizing feeling and smoothness to the skin after washing.

[0077] The amount of the diester of malic acid and a monohydric alcohol in the skin cleansing composition of this embodiment is preferably 3% by mass or less, more preferably 2% by mass or less, and even more preferably 1% by mass or less, from the viewpoint of providing excellent non-stickiness on the skin after washing.

[0078] From the above-mentioned viewpoints, the blending amount of the diester of malic acid and a monohydric alcohol in the skin cleansing composition of this embodiment is preferably 0.01% by mass or more and 3% by mass or less, more preferably 0.05% by mass or more and 2% by mass or less, and even more preferably 0.1% by mass or more and 1% by mass or less.

[0079] (Amphoteric surfactant) The skin cleansing composition of this embodiment may contain one or more amphoteric surfactants.

[0080] Examples of amphoteric surfactants that may be incorporated into the skin cleansing composition of this embodiment include fatty acid amidopropyl betaines, alkyldimethylaminoacetic acid betaines, imidazolinium betaines (such as N-coconut oil fatty acid acyl-N'-carboxyethyl-N'-hydroxyethylethylenediamine sodium, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, and undecyl-N-hydroxyethyl-N-carboxymethylimidazolinium betaine), sulfobetaines (such as sodium N-alkyl-N,N-dimethylammonium-N-propylsulfonate, sodium N-alkyl-N,N-dimethylammonium-N-(2-hydroxypropyl)sulfonate, and sodium N-fatty acid amidopropyl-N,N-dimethylammonium-N-(2-hydroxypropyl)sulfonate), and amine oxides (such as lauric acid amidopropyl dimethylamine oxide).

[0081] Examples of amphoteric surfactants that may be blended in the skin cleansing composition of this embodiment include, as ingredient names in cosmetics, sodium lauramidopropyl betaine, cocamidopropyl betaine, myristamidopropyl betaine, isostearamidopropyl betaine, lauryl betaine, cocobetaine, myristyl betaine, oleyl betaine, behenyl betaine, sodium lauroamphoacetate, disodium lauroamphodiacetate, sodium cocoamphoacetate, disodium cocoamphodiacetate, sodium cocoamphopropionate, disodium cocoamphodipropionate, lauryl betaine, sodium lauroamphoacetate, sodium cocoamphodiacetate, sodium cocoamphopropionate, disodium cocoamphodipropionate, sodium lauroamphoacetate, sodium lauroamphodipropionate, sodium lauroamphoacetate, sodium lauroamphodiacet ...acetate, sodium lauroamphodipropionate, sodium lauroamphoacetate, sodium lauroamphoacetate, sodium lauroamphoacetate, sodium lauroamphodipropionate, sodium lauroamphoacetate, sodium lauroamphoacetate, sodium lauroamphoacetate, sodium lauroampho Examples of suitable hydroxysultaines include decylamine oxide, lauramine oxide, myristamine oxide, cocoamine oxide, stearamine oxide, oleamine oxide, behenamine oxide, lauramidopropylamine oxide, myristamidopropylamine oxide, cocamidopropylamine oxide, decyltetradecylamine oxide, dihydroxyethyl lauramine oxide, and dihydroxyethyl cocamine oxide.

[0082] When an amphoteric surfactant is blended into the skin cleansing composition of this embodiment, the amount of amphoteric surfactant blended is not particularly limited and may be set as appropriate, for example, from 0.1% by mass to 10% by mass.

[0083] (fatty acid or fatty acid salt) The skin cleansing composition of this embodiment may contain a fatty acid or a fatty acid salt. From the viewpoint of providing a more excellent moisturizing feeling on the skin after washing, the skin cleansing composition of this embodiment preferably does not contain a fatty acid or a fatty acid salt, or the content of a fatty acid or a fatty acid salt is preferably 5% by mass or less. The "content of a fatty acid or a fatty acid salt" means the total content of a fatty acid and a fatty acid salt in the skin cleansing composition of this embodiment (when only a fatty acid or a fatty acid salt is contained, this means the content of that fatty acid, and when only a fatty acid and a fatty acid salt are contained, this means the total content of each).

[0084] When the skin cleansing composition of this embodiment contains a fatty acid or a fatty acid salt, the content thereof is preferably 5% by mass or less, more preferably 3% by mass or less, even more preferably 1% by mass or less, even more preferably 0.5% by mass or less, and particularly preferably 0.01% by mass or less, from the viewpoint of providing a more excellent moisturizing feeling on the skin after washing. When the skin cleansing composition of this embodiment contains a fatty acid or a fatty acid salt, the content thereof is, for example, 0.001% by mass or more.

[0085] Examples of the fatty acid or fatty acid salt that may be contained in the skin cleansing composition of this embodiment include fatty acids or fatty acid salts having 8 to 24 carbon atoms.

[0086] Examples of the "salt" in the fatty acid salt that may be contained in the skin cleansing composition of this embodiment include alkali metal salts, alkaline earth metal salts, ammonium salts, alkanolamine salts, and amino acid salts.

[0087] The fatty acid or fatty acid salt that may be contained in the skin cleansing composition of this embodiment may be, for example, a straight-chain fatty acid or fatty acid salt, a branched-chain fatty acid or fatty acid salt, or a hydroxyl-containing fatty acid or fatty acid salt. Examples of straight-chain fatty acids or fatty acid salts include lauric acid or a salt thereof, myristic acid or a salt thereof, palmitic acid or a salt thereof, stearic acid or a salt thereof, behenic acid or a salt thereof, and oleic acid or a salt thereof. Examples of branched-chain fatty acids or fatty acid salts include isostearic acid or a salt thereof, 2-ethylhexanoic acid or a salt thereof, and 18-methyleicosanoic acid or a salt thereof. Examples of hydroxyl-containing fatty acids include hydroxylauric acid or a salt thereof, and hydroxystearic acid or a salt thereof.

[0088] Examples of the fatty acid or fatty acid salt that may be contained in the skin cleansing composition of the present embodiment include, as ingredient names in cosmetics, lauric acid, potassium laurate, magnesium laurate, sodium laurate, TEA laurate, zinc laurate, TEA (lauric acid / myristate), hydroxylauric acid, myristic acid, aluminum myristate, calcium myristate, DIPA myristate, potassium myristate, magnesium myristate, MIPA myristate, sodium myristate, TEA myristate, TIPA myristate, zinc myristate, aluminum dimyristate, aluminum (myristate / palmitate), stearic acid, aluminum stearate, calcium stearate, Examples include potassium stearate, lithium stearate, magnesium stearate, sodium stearate, TEA stearate, zinc stearate, magnesium aluminum hydroxide stearate, aluminum distearate, aluminum di / tristearate, aluminum tristearate, isostearic acid, aluminum isostearate, potassium isostearate, sodium isostearate, behenic acid, calcium behenate, potassium behenate, sodium behenate, oleic acid, potassium oleate, sodium oleate, zinc ethylhexanoate, hydroxystearic acid, potassium hydroxystearate, sodium hydroxystearate, potassium-containing soap base, potassium soap, potassium soap base, coconut potassium soap, and soap base.

[0089] The skin cleansing composition of this embodiment may contain a fatty acid salt by blending the fatty acid salt into the skin cleansing composition. Alternatively, the skin cleansing composition of this embodiment may contain a fatty acid salt by blending a fatty acid (for example, a fatty acid having from 8 to 24 carbon atoms) and an alkali into the skin cleansing composition and forming the fatty acid salt in the composition with the fatty acid and the alkali.

[0090] Examples of alkalis that may be contained in the skin cleansing composition of this embodiment include organic alkalis (2-amino-2-hydroxymethyl-1,3-propanediol, 2-amino-2-ethyl-1-propanol, triethanolamine, arginine, etc.), alkali metal hydroxides (potassium hydroxide, sodium hydroxide, etc.), and inorganic alkalis (ammonia, etc.).

[0091] (Dosage form) The dosage form of the skin cleansing composition of this embodiment when used is not particularly limited, and examples thereof include liquid, cream, gel, solid, paste, and foam (foam).

[0092] (viscosity) The viscosity of the skin cleansing composition of this embodiment is not particularly limited and may be set appropriately. The viscoelasticity value, which is an index of viscosity of the skin cleansing composition of this embodiment, can be measured, for example, using a rheometer (e.g., a stress-controlled rheometer "Rheo Stress 6000" (trade name) manufactured by HAAKE) at a shear rate of 36 s under the conditions of a measurement temperature of 25°C, a diameter of a cone-plate sensor of 35 mm, an inclination angle of the cone-plate sensor of 2°, a steady flow curve mode, and a waiting time of 1 minute. -1 The viscoelasticity measured is 100 mPa·s or more and 5000 mPa·s or less.

[0093] (pH) The pH of the skin cleansing composition of this embodiment at 25° C. is not particularly limited, but is, for example, 4.0 to 7.0. The pH value can be measured by adjusting the skin cleansing composition to 25° C. using a known pH meter.

[0094] (exterior) The appearance of the skin cleansing composition of this embodiment is not particularly limited, and may be, for example, transparent, opaque, or pearlescent. The term "transparent" refers to a state in which, when the skin cleansing composition of this embodiment is left standing in a colorless, transparent glass bottle at 25° C., the appearance can be seen through the glass bottle.

[0095] (Manufacturing method) The method for producing the skin cleansing composition of this embodiment may be any known method for producing skin cleansing compositions, depending on the dosage form to be used. For example, the composition may be produced by mixing a polyoxyethylene alkyl ether carboxylic acid or a salt thereof with one or more compounds selected from the group consisting of acylmethyltaurine or a salt thereof, acylmethylalanine or a salt thereof, and acylglutamic acid or a salt thereof. In this method, a solvent (such as water) may be used as needed.

[0096] (Application) The skin cleansing composition of the present embodiment is used for cleansing the skin. The areas to which the skin cleansing composition of the present embodiment can be applied are not particularly limited, but examples thereof include the skin of the trunk, arms, hands, feet, fingers, neck, face, etc.

[0097] The skin cleansing composition of the present embodiment may be used for cleansing skin other than the face, or may be used for cleansing facial skin. Furthermore, the skin other than the face may be used for cleansing skin of a site other than the face.

[0098] (Product form) The product form of the skin cleansing composition of this embodiment is not particularly limited, but examples include body soap, body shampoo, shower gel, hand soap, hand wash, facial cleanser, cleansing agent, and makeup remover.

[0099] (How to use) The skin cleansing composition of the present embodiment may be used in a manner similar to that of a known skin cleansing composition, for example, by moistening the skin with water, applying the skin cleansing composition of the present embodiment to the skin, rinsing with water, and then drying the skin.

[0100] <Skin cleansing method> The skin cleansing method of the present embodiment is a method of cleansing skin using the skin cleansing composition of the present embodiment described above.

[0101] As the skin cleansing method of this embodiment, any known skin cleansing method may be employed other than using the skin cleansing composition of this embodiment. Therefore, for example, the above-described method for using the skin cleansing composition of this embodiment may be used. [Example]

[0102] The present invention will be described in detail below based on examples, but the present invention should not be construed as being limited by the descriptions in these examples.

[0103] (Experimental Example 1) In Experimental Example 1, the evaluation results of the skin cleansing compositions of Examples 1 to 5 and Comparative Examples 1 to 3 are shown below.

[0104] (Production of Skin Cleansing Compositions of Examples 1 to 5 and Comparative Examples 1 to 3) The following ingredients were mixed in a conventional manner to give the compositions shown in Tables 1 and 2, to produce skin cleansing compositions (body shampoos) of Examples 1 to 5 and Comparative Examples 1 to 3.

[0105] (Ingredients used) Sodium polyoxyethylene lauryl ether acetate (4.5EO), sodium polyoxyethylene lauryl ether acetate (10EO), sodium cocoyl methyl taurate, sodium lauroylmethyl-β-alanine, sodium N-cocoyl acyl-L-glutamate, sodium tetradecene sulfonate, diisostearyl malate, lauramidopropyl betaine, isostearamidopropyl betaine, dipropylene glycol, phenoxyethanol, citric acid, purified water.

[0106] In Tables 1 to 4, the numerical values ​​in the ingredient columns are % by mass, and a "-" indicates that the ingredient is not blended. In the ingredient columns of Tables 1 to 4, the "appropriate amount" of citric acid refers to the amount that results in a pH of 5.4 at 25°C for the skin cleansing composition of each Example or Comparative Example, and the "amount that totals 100" of purified water refers to the amount of purified water that results in the total amount of the skin cleansing composition of each Example or Comparative Example being 100% by mass. In Tables 1 to 4, the "EO" at the end of each polyoxyethylene lauryl ether sodium acetate is an abbreviation for oxyethylene, and the number before EO indicates the average number of moles of oxyethylene added.

[0107] (evaluation) The foaming was evaluated as follows using the skin cleansing compositions of Examples 1 to 5 and Comparative Examples 1 to 3 prepared above. For Examples 1 to 5, the condition of the skin after washing (moisturizing feeling of the skin after washing, smoothness of the skin after washing, and non-stickiness of the skin after washing) was also evaluated.

[0108] (Method for evaluating foaming) The skin cleansing composition of Example 1 was diluted 5-fold with tap water to prepare a solution. This 5-fold dilution was placed in a facial cleansing whisk (trade name: Hoippurun (manufactured by Inomata Chemical Co., Ltd.)) and foamed 15 times. The foam generated in the facial cleansing whisk was then transferred to a 300 mL tall beaker. The height of the foam contained in the beaker was then measured using a ruler from the bottom of the beaker. The foam height was measured at three different points in the beaker, and the average value (N = 3) was calculated. This procedure was performed four times, and an average value (N = 4) was calculated from the four average values ​​calculated each time, and this average value was designated as the "foam height (cm)." The foam height (cm) values ​​for the skin cleansing compositions of Examples 2 to 6 and Comparative Examples 1 to 3 were also obtained in the same manner as for the skin cleansing composition of Example 1. Note that a larger foam height (cm) indicates better foaming.

[0109] (How to evaluate skin condition after washing) The skin cleansing compositions of Examples 1 to 5 were diluted 5-fold with tap water and lathered using a facial cleansing whisk in the same manner as the foaming evaluation method described above. Subsequently, 5 g of the foam from the facial cleansing whisk was applied to wet skin (forearm from elbow to wrist) to cleanse the skin. The skin was then rinsed with running water to wash off the foam, towel-dried, and then dried. The moisturizing feeling, smoothness, and non-stickiness of the skin (dry skin after cleansing) after washing with each skin cleansing composition were scored according to the following evaluation criteria (evaluation criteria: skin cleansing composition of Example 5). The evaluations were performed by six panelists who routinely evaluate skin cleansing compositions, and the evaluation scores of each panelist were added together to determine the total score. The higher the total score of each evaluation point, the better the skin cleansing composition is in each evaluation item of moisturizing feeling, smoothness, and non-stickiness compared to the skin cleansing composition of Example 5, which was used as the evaluation standard.

[0110] (Evaluation score for moisturizing sensation) 1: Compared to skin cleansed with the skin cleansing composition of Example 5, the skin feels more moisturized (the skin feels more moisturized and hydrated to the touch after washing than in Example 5). 0: The skin feels moisturized after washing to the same extent as skin washed with the skin cleansing composition of Example 5 (when touching the skin after washing, it feels moist and moisturized to the same extent as in Example 5). -1: Compared to skin cleansed with the skin cleansing composition of Example 5, the skin felt less moisturized after washing (the skin felt drier and less moisturized to the touch than in Example 5).

[0111] (Smoothness rating) 1: Compared to skin cleansed with the skin cleansing composition of Example 5, the skin felt smoother after washing (skin felt smoother to the touch after washing than did skin cleansing composition of Example 5). 0: The smoothness of the skin after washing is as excellent as that of the skin washed with the skin cleansing composition of Example 5 (the smoothness when touching the skin after washing is the same as that of Example 5). -1: The skin felt less smooth after washing than the skin washed with the skin cleansing composition of Example 5 (the skin felt rougher and more frictional to the touch after washing than the skin washed with the composition of Example 5, and was less smooth).

[0112] (Evaluation score for non-stickiness) 1: The skin felt less sticky after washing compared to the skin washed with the skin cleansing composition of Example 5 (the skin felt less sticky to the touch after washing than in Example 5). 0: The skin felt less sticky after washing, to the same extent as skin washed with the skin cleansing composition of Example 5 (the skin felt less sticky when touched after washing, to the same extent as in Example 5). -1: Skin felt sticky after washing compared to skin washed with the skin cleansing composition of Example 5 (skin felt sticky after washing more than in Example 5).

[0113] (Evaluation results) Tables 1 and 2 show the evaluation results of foaming (foam height (cm)) for the skin cleansing compositions of Examples 1 to 5 and the skin cleansing compositions of Comparative Examples 1 to 3.

[0114] [Table 1]

[0115] [Table 2]

[0116] The results shown in Tables 1 and 2 show that the skin cleansing compositions of Examples 1 to 5, which contain polyoxyethylene alkyl ether carboxylic acid or a salt thereof and acylmethyl taurine, etc., all had higher foaming (cm) values ​​and superior foaming properties than the skin cleansing compositions of Comparative Examples 1 to 3, which do not contain either polyoxyethylene alkyl ether carboxylic acid or a salt thereof or acylmethyl taurine, etc. Therefore, it can be seen that the skin cleansing compositions containing polyoxyethylene alkyl ether carboxylic acid or a salt thereof and acylmethyl taurine, etc., have superior foaming properties.

[0117] The results shown in Tables 1 and 2 indicate that the skin cleansing compositions of Examples 1 to 4, which contained α-olefin sulfonic acid or a salt thereof, had higher foaming (cm) values ​​and better foaming properties than the skin cleansing composition of Example 5, which did not contain α-olefin sulfonic acid or a salt thereof. Therefore, it can be seen that skin cleansing compositions containing α-olefin sulfonic acid or a salt thereof in addition to polyoxyethylene alkyl ether carboxylic acid or a salt thereof and acylmethyl taurine, etc., have better foaming properties. Furthermore, the skin cleansing composition of Example 3 had a higher foaming (cm) value and better foaming properties than the skin cleansing compositions of Examples 1, 2, and 4. Therefore, it can be seen that the use of acylmethylalanine or a salt thereof as the acylmethyl taurine, etc., in skin cleansing compositions provides even better foaming properties.

[0118] Table 3 shows the evaluation results of the skin cleansing compositions of Examples 1 to 5 in terms of moisturizing feeling, smoothness, and non-stickiness.

[0119] [Table 3]

[0120] Comparing the evaluation results of the skin cleansing compositions of Examples 1 and 2 from the results shown in Table 3, the skin cleansing composition of Example 2 (containing sodium polyoxyethylene lauryl ether acetate (10 EO)) was superior in the evaluation results of moisturizing feel, smoothness, and non-stickiness compared to the skin cleansing composition of Example 1 (containing sodium polyoxyethylene lauryl ether acetate (4.5 EO)). Therefore, it can be seen that when a polyoxyethylene lauryl ether carboxylic acid or a salt thereof having an average number of moles of oxyethylene added of 6 or more is used as the polyoxyethylene alkyl ether carboxylic acid or a salt thereof in a skin cleansing composition, the composition is superior in moisturizing feel, smoothness, and non-stickiness.

[0121] Comparing the evaluation results of the skin cleansing compositions of Examples 1, 3, and 4 from the results shown in Table 3, the evaluation results for moisturizing feel, smoothness, and non-stickiness were superior for the skin cleansing composition of Example 1 (containing sodium coconut oil fatty acid methyl taurate), the skin cleansing composition of Example 4 (containing sodium N-coconut oil fatty acid acyl-L-glutamate), and the skin cleansing composition of Example 3 (containing sodium lauroylmethyl-β-alanine), in that order. Therefore, it can be seen that skin cleansing compositions using either acyl methyl taurine or a salt thereof, or acyl glutamic acid or a salt thereof as the acyl methyl taurine, etc., are excellent in moisturizing feel, smoothness, and non-stickiness, and that using acyl methyl taurine or a salt thereof as the acyl methyl taurine, etc., are even more excellent in moisturizing feel, smoothness, and non-stickiness. Furthermore, the skin cleansing compositions of Examples 1 to 4, which contained α-olefin sulfonic acid or a salt thereof, were superior in smoothness and non-stickiness compared to the skin cleansing composition of Example 5, which did not contain α-olefin sulfonic acid or a salt thereof. Therefore, it can be seen that skin cleansing compositions containing α-olefin sulfonic acid or a salt thereof in addition to polyoxyethylene alkyl ether carboxylic acid or a salt thereof, acylmethyl taurine, etc., are superior in smoothness and non-stickiness.

[0122] (Experimental Example 2) In Experimental Example 2, the evaluation results of the skin cleansing compositions of Examples 1 and 6 are shown below.

[0123] (Production of Skin Cleansing Composition of Example 6) The skin cleansing composition (body shampoo) of Example 6 was produced by mixing the components used in the production of the skin cleansing compositions of Examples 1 to 5 and Comparative Examples 1 to 3 in Experimental Example 1 and diisostearyl malate in a conventional manner to obtain the composition shown in Table 3.

[0124] (evaluation) The skin cleansing composition of Example 1 produced in Experimental Example 1 and the skin cleansing composition of Example 6 produced above were used to evaluate foaming in the same manner as in Experimental Example 1. The skin cleansing compositions of Examples 1 and 6 were also evaluated for their post-wash skin condition (moisturizing feeling of skin after washing, smoothness of skin after washing, and non-stickiness of skin after washing) in the same manner as in Experimental Example 1. In this case, the evaluation of the post-wash skin condition was based on the skin cleansing composition of Example 1.

[0125] (Evaluation results) Table 4 shows the evaluation results for foaming (foam height (cm)) of the skin cleansing compositions of Examples 1 and 6. Table 5 also shows the evaluation results for moisturizing feel, smoothness, and non-stickiness of the skin cleansing compositions of Examples 1 and 6.

[0126] [Table 4]

[0127] From the results shown in Table 4, the skin cleansing composition of Example 1 (containing no diisostearyl malate) and the skin cleansing composition of Example 6 (containing diisostearyl malate) both had higher foaming (cm) values ​​and were superior in foaming compared to the skin cleansing compositions of Comparative Examples 1 to 3 shown in Table 2.

[0128] [Table 5]

[0129] The results shown in Table 5 show that the skin cleansing composition of Example 6 (containing diisostearyl malate) was superior in the evaluation results of moisturizing feel, smoothness, and non-stickiness compared to the skin cleansing composition of Example 1 (containing no diisostearyl malate), and was particularly superior in the evaluation results of moisturizing feel and smoothness. Therefore, it can be seen that the use of diisostearyl malate in a skin cleansing composition results in excellent moisturizing feel, smoothness, and non-stickiness.

[0130] (Prescription example) Formulation examples of skin cleansing compositions are shown below (formulations 1 to 60).

[0131] (Prescriptions 1-30) Tables 6 to 9 show the body shampoos with formulations 1 to 30. In the tables, the names of ingredients are the names of ingredients displayed in cosmetics, and the numbers in the ingredient column are mass %.

[0132] [Table 6]

[0133] [Table 7]

[0134] [Table 8]

[0135] [Table 9]

[0136] (Prescriptions 31-60) The body shampoos of Formulations 31 to 60 were prepared by replacing 0.1 mass % of water in each of the body shampoos of Formulations 1 to 30 in Tables 6 to 9 with 0.1 mass % of diisostearyl malate.

Claims

1. Polyoxyethylene alkyl ether carboxylic acid or a salt thereof, and one or more selected from acylmethyltaurine or a salt thereof, acylmethylalanine or a salt thereof, and acylglutamic acid or a salt thereof; A skin cleansing composition containing

2. 2. The skin cleansing composition according to claim 1, which contains α-olefin sulfonic acid or a salt thereof.

3. 3. The skin cleansing composition according to claim 1, wherein the one or more selected from acylmethyltaurine or a salt thereof, acylmethylalanine or a salt thereof, and acylglutamic acid or a salt thereof are blended with one or more selected from acylmethyltaurine or a salt thereof, and acylmethylalanine or a salt thereof.

4. 3. The skin cleansing composition according to claim 1, further comprising a diester of malic acid and a monohydric alcohol.

5. 3. The skin cleansing composition according to claim 1, wherein the polyoxyethylene alkyl ether carboxylic acid or salt thereof is a polyoxyethylene alkyl ether carboxylic acid or salt thereof having an average number of moles of oxyethylene added of 10 or less.

6. A method for cleansing skin using the skin cleansing composition according to claim 1 or 2.

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