JP7602864B2 - Skin cleansing spray - Google Patents

Description

The present invention relates to a skin cleansing spray that is sprayed directly onto the skin.

A variety of skin cleansing compositions, such as face washes, body soaps, and shampoos, are available as products intended to cleanse the skin and keep it clean. The mechanism by which skin cleansing compositions cleanse the skin is that the surfactant adsorbs to dirt, reducing the surface tension between the dirt and water, and, together with the mechanical force caused by friction, causes the dirt to float up into the water. For this cleaning mechanism to function effectively, it is necessary to incorporate the surfactant at a concentration equal to or higher than the critical micelle concentration.

On the other hand, surfactants with too strong cleansing power can cause skin irritation, resulting in dry skin and other skin problems. For this reason, various formulas have been proposed that devise combinations and amounts of cleansing ingredients to make the product more mild on the skin. In particular, it is generally accepted that formulas that improve foam quality, such as foaming power and foam retention, are excellent for making the product more mild on the skin, as the foam formed during cleansing is recognized to reduce friction caused by direct contact between the skin and fingers.

For this reason, in recent years, various pump-foamer-type skin cleansers have been proposed, and they have attracted attention not only for their convenience in easily obtaining high-quality foam, but also for their gentleness to the skin. Specifically, Patent Document 1 discloses a liquid skin cleansing product comprising a former container and a liquid skin cleansing composition filled in the former container, the liquid skin cleansing composition containing (A) 3 to 10% by mass of a specific fatty acid salt having a linear or branched monovalent hydrocarbon group having 7 to 21 carbon atoms, (B) a specific copolymer of dimethyldiallylammonium chloride and acrylic acid and/or acrylamide, and (C) a sugar alcohol, and the mass ratio (A)/(B) of the content of component (A) to the content of component (B) is 20 to 250. Patent Document 2 discloses a skin cleansing composition that contains (a) 2 to 9% by mass of a fatty acid salt, (b) 0.5 to 4% by mass of lauryldimethylaminoacetate betaine, and (c) 1 to 10% by mass of one or more dihydric alcohols, and the sum of the amounts (mass%) of the (a) and (b) components (a) + (b) is 3 to 10% by mass, and the ratio of the amounts (b)/(a) is 0.1 to 0.5, and is filled in a former container. Patent Document 3 discloses a cleansing composition that is discharged from a former container and contains (a) lauryldimethylaminoacetate betaine and (b) 4 to 15% by mass of a higher fatty acid soap formed from a fatty acid having 5 to 25 carbon atoms and having a specific composition.

International Publication No. 2014/003114 JP 2016-098182 A International Publication No. 2017/081897

Pump-former type skin cleansing compositions contain a relatively small amount of surfactant, and in that respect, they tend to cause less irritation to the skin than solid or semi-solid skin cleansing compositions. On the other hand, pump-former type skin cleansing compositions are essentially designed to be discharged in a foam state, so it is unavoidable from the standpoint of their composition to contain the minimum amount of surfactant necessary to exert foaming power.

In addition, a wide variety of skin cleansers have been developed to remove dirt and body fluids such as sebum and sweat, excluding skin cleansers intended to remove makeup (cleansing). However, all skin cleansers, without exception, are designed to be lathered before application to the skin, and it is also common knowledge that lathering well before washing is preferable in terms of reducing friction on the skin. Although foam can reduce physical friction by being placed between the skin and the hands, the foam itself is rubbed against the skin, which in turn generates physical friction and is an irritant to the skin. Irritation remains a particular concern for sensitive skin.

As such, there is a limit to how much skin cleansers can reduce the burden on the skin when used in the same way as before. For this reason, it is considered necessary for skin cleansers to be less irritating than ever before so that they can be used on sensitive skin.

Therefore, the present invention aims to provide a skin cleansing composition that is used in a manner different from conventional methods.

The inventors came up with the novel idea of directly spraying the skin cleansing composition onto the skin, without foaming it beforehand, in order to further reduce skin irritation. They also discovered that by making an amphiphilic ester coexist with the surfactant and adjusting the pH to 3 to 8, effective cleansing power can be obtained without foaming it beforehand. The present invention was completed through further investigations based on this finding.

That is, the present invention provides the following aspects.
Item 1. A skin cleansing spray agent containing (A) a surfactant and (B) an amphiphilic ester, having a pH of 3 to 8, and contained in a spray container.
Item 2. The skin cleansing spray according to Item 1, wherein the spray container is a pump-type spray container.
Item 3. The skin cleansing spray according to Item 1, wherein the spray container is an aerosol spray container.
Item 4. The skin cleansing spray according to any one of Items 1 to 3, wherein the component (B) is selected from the group consisting of dicarboxylate bis(polyoxyalkylene alkyl ether) esters, dicarboxylate dialkoxyalkyl esters, and polyglyceryl-10 (eicosadioate/tetradecanedioate).
Item 5. The skin cleansing spray according to any one of Items 1 to 4, wherein the dicarboxylic acid bis(polyoxyalkylene alkyl ether) ester is cyclohexane-1,4-dicarboxylate bis(ethoxydiglycol).
Item 6. The skin cleansing spray according to any one of items 1 to 5, wherein the content of the component (A) is 0.025 to 2% by weight.
Item 7. The skin cleansing spray according to any one of Items 1 to 6, which is applied to sensitive skin.

According to the present invention, the skin cleansing composition can exhibit excellent cleansing power while reducing skin irritation, and therefore, unlike conventional applications in which the skin is foamed before application to the skin, a new application can be provided in which the skin cleansing composition is directly sprayed onto the skin for application. Since cleaning is possible without foaming beforehand, the amount of surfactant in the skin cleansing liquid composition can be significantly reduced compared to the amount contained in conventional skin cleansing liquid compositions, which makes it possible to further reduce skin irritation. Therefore, the skin cleansing spray agent can be suitably used for cleaning skin that has become sensitive to irritation.

The skin cleansing spray of the present invention is characterized by containing (A) a surfactant (hereinafter sometimes referred to as component (A)) and (B) an amphiphilic ester (hereinafter sometimes referred to as component (B)), being adjusted to a predetermined pH, and being contained in a spray container. The skin cleansing spray of the present invention is described in detail below.

(A) Surfactant The skin cleansing spray of the present invention contains a surfactant as component (A). The surfactant is not particularly limited, but from the viewpoint of suppressing irritation to the skin, preferred examples include anionic surfactants, nonionic surfactants, amphoteric surfactants, natural surfactants, etc. As the surfactant, one of anionic surfactants, nonionic surfactants, amphoteric surfactants, and natural surfactants may be used alone, or two or more of them may be used in any combination.

Examples of anionic surfactants that can be used in the present invention include carboxylic acid type, sulfonic acid type, sulfate ester type, and phosphate ester type surfactants.

Specific examples of carboxylic acid type surfactants include saturated or unsaturated fatty acids having 6 to 22 carbon atoms, such as octanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, and stearic acid; and N-acylamino acids (carboxylic acid type amino acid anionic surfactants) having saturated or unsaturated N-acyl groups having 8 to 24 carbon atoms, such as octanoyl group, decanoyl group, lauroyl group, myristoyl group, palmitoyl group, and cocoyl group.

Examples of carboxylic acid type amino acid anionic surfactants include N-acyl amino acids having a saturated or unsaturated N-acyl group with 8 to 24 carbon atoms, such as an octanoyl group, a decanoyl group, a lauroyl group, a myristoyl group, a palmitoyl group, and a cocoyl group. Examples of N-acyl amino acids in carboxylic acid type amino acid anionic surfactants include N-acylsarcosine, N-acylaspartic acid, N-acylglutamic acid, and N-acyl-N-methyl-β-alanine. More specific examples of carboxylic acid type amino acid anionic surfactants include N-lauroylsarcosine, cocoylsarcosine, N-lauroylaspartic acid, cocoylaspartic acid, N-lauroylglutamic acid, cocoylglutamic acid, N-lauroyl-N-methyl-β-alanine, and cocoylmethylalanine.

Specific examples of sulfonic acid surfactants include esters of fatty acids with 6 to 22 carbon atoms, such as cocoyl isethionic acid, and isethionic acid; alkylsulfonic acids with 6 to 22 carbon atoms, such as hexanesulfonic acid, octanesulfonic acid, decanesulfonic acid, and dodecanesulfonic acid; alkylbenzenesulfonic acids with an alkyl group with 10 to 16 carbon atoms, such as alkylbenzenesulfonic acid; and N-acyl-N-methyltaurine (sulfonic acid amino acid anionic surfactants) with saturated or unsaturated N-acyl groups with 8 to 24 carbon atoms, such as octanoyl, decanoyl, lauroyl, myristoyl, palmitoyl, and cocoyl groups.

Examples of sulfonic acid type amino acid anionic surfactants include N-acyl-N-methyltaurine having a saturated or unsaturated N-acyl group with 8 to 24 carbon atoms, such as an octanoyl group, a decanoyl group, a lauroyl group, a myristoyl group, a palmitoyl group, or a cocoyl group. More specific examples of sulfonic acid type amino acid anionic surfactants include N-myristoyl-N-methyltaurine, N-lauroyl-N-methyltaurine, and cocoyl methyltaurine.

Specific examples of sulfate ester type surfactants include esters of saturated or unsaturated fatty acids having 10 to 22 carbon atoms, such as lauryl sulfate and myristyl sulfate, and sulfuric acid.Specific examples of phosphate ester type surfactants include esters of saturated or unsaturated fatty acids having 8 to 24 carbon atoms, such as lauryl phosphoric acid, and phosphoric acid.

These anionic surfactants may be in the form of a salt, for example, an alkali metal salt such as a sodium salt or a potassium salt; a triethanolamine (TEA) salt; an ammonium salt, etc.

Among these anionic surfactants, from the viewpoint of obtaining better skin irritation reduction properties and cleaning power, carboxylic acid type surfactants and sulfonic acid type surfactants are preferred, and carboxylic acid type amino acid anionic surfactants and sulfonic acid type amino acid anionic surfactants are more preferred. When the pH of the skin cleansing spray of the present invention is, for example, 3 to 6, carboxylic acid type amino acid anionic surfactants and sulfonic acid type amino acid anionic surfactants are preferably used from the viewpoint of suppressing the feeling of tightness due to insufficient moisturization, or from the viewpoint of suppressing the feeling of tightness due to insufficient moisturization and cleaning power. More specifically, when the pH of the skin cleansing spray of the present invention is, for example, 3 to 4, carboxylic acid type amino acid anionic surfactants and sulfonic acid type amino acid anionic surfactants are preferably used from the viewpoint of suppressing the feeling of tightness due to insufficient moisturization and cleaning power, and when the pH is, for example, 5 to 6, they are preferably used from the viewpoint of suppressing the feeling of tightness due to insufficient moisturization and cleaning power.

Of these, from the viewpoint of cleaning power and/or reduced skin irritation, etc., preferred are N-acyl glutamic acid and N-acylaspartic acid having a saturated or unsaturated acyl group with 8 to 24 carbon atoms, and fatty acid amidosulfonic acids and salts thereof having 8 to 22 carbon atoms, more preferred are cocoyl glutamic acid, N-lauroyl aspartic acid, cocoyl methyl taurine and salts thereof, and even more preferred are triethanolamine cocoyl glutamate, sodium N-lauroyl aspartate, and sodium cocoyl methyl taurine.

These anionic surfactants may be used alone or in combination of two or more.

Nonionic surfactants that can be used in the present invention include, for example, ester type, ether type, ester-ether type, alkanolamide type, alkyl glycoside type, alcohol type, and other surfactants.

Nonionic surfactants are preferably used from the viewpoint of cleaning power and skin irritation reduction when the pH of the skin cleansing spray of the present invention is, for example, 5 to 8, preferably 5 to 6. Specific examples of ester-type surfactants include mono- or diesters of saturated or unsaturated fatty acids having 8 to 20 carbon atoms and glycerin, such as glycol dilaurate, glycol monostearate, glycol distearate, glyceryl monolaurate, glyceryl dilaurate, glyceryl monostearate, and glyceryl distearate; sorbitan fatty acid esters; and sucrose fatty acid esters.

Specific examples of ether-type surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polyoxypropylene glycols, etc.

Examples of ester/ether type surfactants include polyoxyethylene hydrogenated castor oil, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene hexitane fatty acid ester, sorbitan fatty acid ester polyethylene glycol, etc.

Specific examples of alkanolamide surfactants include cocamide DEA (coconut oil fatty acid diethanolamide), lauric acid diethanolamide, oleic acid diethanolamide, stearic acid diethanolamide, etc.

Specific examples of alkyl glycoside surfactants include octyl glucoside, decyl glucoside, lauryl glucoside, etc.

Examples of alcohol-based surfactants include cetanol, stearyl alcohol, and oleyl alcohol.

Among these nonionic surfactants, from the viewpoint of obtaining better skin irritation reduction and cleaning power, preferred are ester/ether type surfactants and alkanolamide type surfactants, more preferred are polyoxyethylene hydrogenated castor oil and cocamide DEA, and even more preferred is polyoxyethylene hydrogenated castor oil.

These nonionic surfactants may be used alone or in combination of two or more.

Examples of amphoteric surfactants that can be used in the present invention include alkyl betaine type, fatty acid amidopropyl betaine type, and amine oxide type surfactants.

Specific examples of alkyl betaine type surfactants include lauryl dimethyl amino acetate betaine, stearyl dimethyl amino acetate betaine, octadecyl aminomethyl dimethyl sulfopropyl betaine, etc.

Specific examples of fatty acid amidopropyl betaine amphoteric surfactants include amidobetaines (amino acid-based amphoteric surfactants) such as cocamidopropyl betaine, and sulfobetaines such as cocamidopropyl hydroxysultaine.

Specific examples of amine oxide amphoteric surfactants include lauryl dimethylamine N-oxide and oleyl dimethylamine N-oxide.

These amphoteric surfactants may be in the form of a salt, for example, an alkali metal salt such as a sodium salt or a potassium salt; a triethanolamine (TEA) salt; an ammonium salt, etc.

Among these amphoteric surfactants, from the viewpoint of reducing skin irritation and obtaining better cleaning power, fatty acid amidopropyl betaine type surfactants are preferred, more preferably amidobetaines (amino acid-based amphoteric surfactants) such as cocamidopropyl betaine, and even more preferably cocamidopropyl betaine.

These amphoteric surfactants may be used alone or in combination of two or more.

The natural surfactants used in the present invention include lecithin and lysolecithin; saponins such as quillaja saponin, soybean saponin, yucca saponin, soybean saponin, beet saponin, adzuki bean saponin, carrot saponin, tea seed saponin, loofah saponin, and Centella saponin.

Lecithin is a mixture of phospholipids such as phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, and phosphatidylinositol, as well as other components such as triglycerides, fatty acids, and carbohydrates from vegetable oils, and is a well-known ingredient in pharmaceuticals, quasi-drugs, and cosmetics.

Lecithin may be natural lecithin derived from animals or plants (e.g., soybean lecithin, egg yolk lecithin, etc.), chemically processed natural lecithin, or purified natural lecithin. Chemically processed natural lecithin includes hydrogenated lecithin obtained by hydrogenation (e.g., fully hydrogenated lecithin and partially hydrogenated lecithin), and hydroxide lecithin obtained by hydroxide treatment. Refined natural lecithin includes lecithin with an increased phosphatidylcholine content using a solvent such as acetone.

Lysolecithin includes the lyso form of the above-mentioned lecithin (natural lecithin, chemically treated natural lecithin, and purified natural lecithin). Lysolecithin has a structure in which the fatty acid at the 2nd position of phosphatidylcholine has been removed by hydrolysis (dissolution) of lecithin with an enzyme such as phospholipase A2.

Among these natural surfactants, from the viewpoint of obtaining better skin irritation reduction properties and cleaning power, lecithin, lysolecithin, and saponin are preferred, lecithin and lysolecithin are more preferred, and lysolecithin is even more preferred.

These natural surfactants may be used alone or in combination of two or more.

The content of the (A) component in the skin cleansing spray of the present invention is not particularly limited and can be appropriately determined according to the cleaning power to be imparted. Since the skin cleansing spray of the present invention can clean the skin without applying physical friction, the amount of surfactant in the skin cleansing spray can be significantly reduced compared to the amount contained in the conventional skin cleansing liquid composition, and the cleaning power can be effectively exerted even with a small amount of surfactant that does not originally exert an effective cleaning power. From this viewpoint, the content of the (A) component in the skin cleansing spray of the present invention is preferably 0.025 to 2% by weight. Furthermore, from the viewpoint of further suppressing skin irritation and a feeling of tightness due to insufficient moisture, the upper limit of the above content range of the (A) component may be 1.5% by weight or less, preferably 1% by weight or less, more preferably 0.9% by weight or less, even more preferably 0.6% by weight or less, and even more preferably 0.2% by weight or less. On the other hand, from the viewpoint of obtaining a superior cleaning power, the lower limit of the range of the content of component (A) is preferably 0.1% by weight or more, more preferably 0.5% by weight or more, even more preferably 1.5% by weight or more, and particularly preferably 1.8% by weight or more.

The skin cleansing spray of the present invention contains an amphiphilic ester as component (B). Component (B) does not exhibit a cleansing effect alone, but by coexisting with component (A), the cleansing power of the skin cleansing spray can be improved while maintaining low irritation.

In the present invention, the amphiphilic ester is one that dissolves at 2% by mass or more at room temperature in ion-exchanged water adjusted to a conductivity of 70 to 110 μs/m, as measured by the method specified in the general testing method of the Japanese Pharmacopoeia, and dissolves at 10% by mass or more in the oil agent isotridecyl isononanoate (Salacos 913, manufactured by Nisshin Oillio Group, Ltd.) at room temperature (25°C), and ester-based surfactants are excluded.

The amphiphilic ester is not particularly limited, but from the viewpoint of obtaining better skin irritation reduction properties and cleaning power, it is preferable that it is selected from the group consisting of dicarboxylate bis(polyoxyalkylene alkyl ether) esters, dicarboxylate dialkoxyalkyl esters, and polyglyceryl-10 (eicosane diacid/tetradecanedioic acid). As the amphiphilic ester, any one of dicarboxylate bis(polyoxyalkylene alkyl ether) esters, dicarboxylate dialkoxyalkyl esters, and polyglyceryl-10 (eicosane diacid/tetradecanedioic acid) may be used alone, or two or more kinds may be used in combination. Among these amphiphilic esters, dicarboxylate bis(polyoxyalkylene alkyl ether) esters are more preferable from the viewpoint of obtaining better skin irritation reduction properties and cleaning power.

The dicarboxylic acid bis(polyoxyalkylene alkyl ether) ester used in the present invention is a diester compound of a dicarboxylic acid and a polyoxyalkylene alkyl ether. Specific examples of the dicarboxylic acid constituting the diester compound of the dicarboxylic acid bis(polyoxyalkylene alkyl ether) ester include, for example, oxalic acid, malonic acid, succinic acid, tartaric acid, malic acid, glutaric acid, adipic acid, pemelic acid, suberic acid, azelaic acid, sebacic acid, aspartic acid, glutamic acid, acetone dicarboxylic acid, phthalic acid, and cyclohexane-1,4-dicarboxylic acid. Examples of the polyoxyalkylene alkyl ether constituting the diester compound include, for example, polyoxyethylene monoalkyl ether, and more specifically, for example, diethylene glycol monoethyl ether and triethylene glycol monoethyl ether.

Among these dicarboxylic acid bis(polyoxyalkylene alkyl ether) esters, from the viewpoint of obtaining better skin irritation reduction properties and cleaning power, preferably, a diester compound of cyclohexane-1,4-dicarboxylic acid and diethylene glycol monoethyl ether, specifically, a compound called cyclohexane-1,4-dicarboxylic acid bisethoxydiglycol, represented by the INCI name (International Cosmetic Ingredient Dictionary and Handbook, 13th Edition, Vol. 1, CTFA, 2010, p. 331): BIS-ETHOXYDIGLYCOL CYCLOHEXANE 1,4-DICARBOXYLATE, and a diester compound of succinic acid and diethylene glycol monoethyl ether, specifically, a diester compound of succinic acid and diethylene glycol monoethyl ether, represented by the INCI name (International Cosmetic Ingredient Dictionary and Handbook, 13th Edition, Vol. 1, CTFA, 2010, p. 331): BIS-ETHOXYDIGLYCOL CYCLOHEXANE 1,4-DICARBOXYLATE, are used. Ingredient Dictionary and Handbook, 13th Edition, Vol. 1, CTFA, 2010, pp. 331-332): Examples include a compound called bis-ethoxydiglycol succinate, which is represented as BIS-ETHOXYDIGLYCOL SUCCINATE, and more preferably bis-ethoxydiglycol cyclohexane-1,4-dicarboxylate.

In the present invention, a specific example of the bis-ethoxydiglycol cyclohexane-1,4-dicarboxylate is "Neosolue-Aquilio (trade name)" manufactured by Nippon Fine Chemicals Co., Ltd., and the like. A specific example of the bis-ethoxydiglycol succinate is "Hi-Aquostar DCS (trade name)" manufactured by Kokyu Alcohol Kogyo Co., Ltd., and the like.

These dicarboxylic acid bis(polyoxyalkylene alkyl ether) esters may be used alone or in combination of two or more.

The dicarboxylic acid dialkoxyalkyl ester used in the present invention is a diester compound of a dicarboxylic acid and an alkoxy alcohol. Specific examples of the dicarboxylic acid constituting the diester compound of the dicarboxylic acid dialkoxyalkyl include oxalic acid, malonic acid, succinic acid, tartaric acid, malic acid, glutaric acid, adipic acid, pemelic acid, suberic acid, azelaic acid, sebacic acid, aspartic acid, glutamic acid, acetone dicarboxylic acid, phthalic acid, and cyclohexane-1,4-dicarboxylic acid. Examples of the alkoxy alcohol constituting the diester compound include 2-methoxyethanol and 2-ethoxyethanol.

Among these dicarboxylate dialkoxyalkyl esters, from the viewpoint of obtaining the effects of the present invention more satisfactorily, a diester compound of succinic acid and 2-ethoxyethanol, specifically diethoxyethyl succinate, is preferred.

These dicarboxylic acid dialkoxyalkyl esters may be used alone or in combination of two or more.

The polyglyceryl-10 (eicosane diacid/tetradecanedioic acid) used in the present invention is not particularly limited, but examples include "Neosolue-Aqua (trade name)" and "Neosolue-AquaS (trade name)" manufactured by Nippon Fine Chemical Co., Ltd.

The content of component (B) in the skin cleansing spray of the present invention is not particularly limited, but may be, for example, 0.1% by weight or more. From the viewpoint of obtaining even better cleansing power and/or from the viewpoint of further reducing the feeling of tightness due to insufficient moisturization, the content of component (B) is preferably 0.5% by weight or more, more preferably 1.5% by weight or more, and more preferably 2% by weight or more. The upper limit of the range of the content of component (B) is not particularly limited, but from the viewpoint of the stability of the skin cleansing spray, for example, it may be 5% by weight or less, preferably 4% by weight or less, and more preferably 3% by weight or less.

In the skin cleansing spray of the present invention, the ratio of component (A) to component (B) is not particularly limited and is determined by the above-mentioned respective contents, but from the viewpoint of obtaining better skin irritation reduction properties and cleaning power, for example, 0.1 to 100 parts by weight, preferably 0.1 to 10 parts by weight, more preferably 0.5 to 5 parts by weight, and even more preferably 1 to 5 parts by weight of component (B) per 1 part by weight of component (A).

Other Components In addition to the above-mentioned components, the skin cleansing spray of the present invention may contain other bases and additives required for formulation, etc., within the scope of not impairing the effects of the present invention. Such additives are not particularly limited as long as they are pharma- ceutically acceptable, and examples of such additives include aqueous bases such as water, lower alcohols having 1 to 5 carbon atoms (ethanol, isopropanol, etc.), and polyhydric alcohols (ethylene glycol, 1,3-butylene glycol (1,3-BG), propylene glycol, isoprene glycol, diethylene glycol, dipropylene glycol, polypropylene glycol, glycerin, etc.); preservatives (phenoxyethanol, methylparaben, propylparaben, benzoic acid, sodium benzoate, sorbic acid, etc.), flavoring agents (citral, 1,8-cineole, citronellal, fa Lunesol, etc.), colorants (tar dyes (Brown No. 201, Blue No. 201, Yellow No. 4, Yellow No. 403, etc.), cocoa dyes, chlorophyll, aluminum oxide, etc.), thickeners (hydroxypropyl cellulose, hydroxyethyl cellulose, cross-linked acrylic acid polymers, carboxyvinyl polymers, hypromellose, polyvinylpyrrolidone, sodium alginate, ethyl cellulose, sodium carboxymethyl cellulose, xanthan gum, carrageenan, etc.), pH adjusters (phosphoric acid, hydrochloric acid, formic acid, acetic acid, citric acid, glycolic acid, glucuronic acid, chloroacetic acid, succinic acid, fumaric acid, tartaric acid, maleic acid, malonic acid, malic acid, milk Acid, benzoic acid, potassium phosphate, dipotassium phosphate, disodium phosphate, trisodium phosphate, ammonium phosphate, pentasodium triphosphate, potassium citrate, sodium citrate (trisodium citrate), calcium citrate, sodium glycolate, sodium silicate, sodium succinate, trisodium sulfosuccinate, sodium fumarate, potassium tartrate, disodium tartrate, tetrapotassium pyrophosphate, disodium pyrophosphate, tetrasodium pyrophosphate, sodium borate, potassium sulfate, sodium bisulfate, sodium hydroxide, potassium hydroxide, triethanolamine, triisopropanol amines, etc., preferably citric acid and potassium hydroxide. ), wetting agents (sodium dl-pyrrolidone carboxylate solution, D-sorbitol solution, macrogol, etc.), stabilizers (dibutyl hydroxytoluene, butyl hydroxyanisole, sodium edetate, sodium metaphosphate, L-arginine, L-aspartic acid, DL-alanine, glycine, sodium erythorbate, propyl gallate, sodium sulfite, sulfur dioxide, chlorogenic acid, catechin, rosemary extract, etc.), antioxidants, ultraviolet absorbers, chelating agents, adhesives, buffers, solubilizing agents, solubilizers, preservatives, and other additives. These substrates and additives may be used alone or in combination of two or more. The content of these substrates and additives can be appropriately set depending on the formulation form, etc.

In addition to the above-mentioned components, the skin cleansing spray of the present invention may contain other pharmacological ingredients as necessary within the scope of the present invention, so long as the effects of the present invention are not impaired. Examples of such pharmacological ingredients include vitamins (vitamin A, vitamin B1, vitamin B2, vitamin B5, vitamin B6, vitamin B12, vitamin C, vitamin D, vitamin K, niacin, folic acid, biotin, lycopene, etc.), antihistamines (diphenhydramine, diphenhydramine hydrochloride, etc.), local anesthetics (procaine, tetracaine, bupivacaine, mepivacaine, chloroprocaine, proparacaine, meprylcaine or salts thereof, orthocaine, oxethazaine, oxypolyethyleneoxydecane, scopolamine extract, percaine, etc.), and the like. These include minpase, tesitdesitin, etc.), anti-inflammatory agents (indomethacin, felbinac, diclofenac sodium, loxoprofen sodium, etc.), skin protectants (collodion, castor oil, etc.), blood circulation promoting ingredients (vanillylamide nonylate, benzyl nicotinate, capsaicin, chili pepper extract, etc.), cooling agents (menthol, camphor, borneol, peppermint water, peppermint oil, etc.), mucopolysaccharides (sodium chondroitin sulfate, glucosamine, hyaluronic acid, cationized hyaluronic acid (dihydroxypropyltrimonium hyaluronate, etc.), etc.). These pharmacological ingredients may be used alone or in combination of two or more. When these pharmacological ingredients are contained, the content may be appropriately set depending on the type of pharmacological ingredient used, the expected effect, etc.

pH
The pH of the skin cleansing spray of the present invention is adjusted to 3 to 8 from the viewpoint of reducing skin irritation and obtaining cleaning power. The preferred pH of the skin cleansing spray of the present invention may vary depending on the type of component (A), etc., but for example, when a carboxylic acid type amino acid anionic surfactant and/or a sulfonic acid type amino acid anionic surfactant is used as the component (A), from the viewpoint of suppressing a feeling of tension due to insufficient moisture, or from the viewpoint of suppressing a feeling of tension due to insufficient moisture and cleaning power, it is preferably 3 to 6, more preferably 3 to 5, from the viewpoint of suppressing a feeling of tension due to insufficient moisture, it is even more preferably 3 to 4, and from the viewpoint of suppressing a feeling of tension due to insufficient moisture and cleaning power, it is even more preferably 5 to 6; when a nonionic surfactant is used as the component (A), it is preferably 5 to 8, more preferably 5 to 6, from the viewpoint of cleaning power and reducing skin irritation. In the present invention, pH refers to the pH at 25°C.

Form The skin cleansing spray of the present invention is in the form of a liquid or gel at room temperature. The viscosity of the skin cleansing spray of the present invention is 10,000 mPa·s or less, preferably 5,000 mPa·s or less at 20° C. The viscosity is a value measured by a BL viscometer (rotor No. 3, 6 rpm, 20° C.).

The container for storing the skin cleansing spray of the present invention is not particularly limited, but is limited to being a spray type container. The spray type container in the present invention is one that discharges the contents in a mist state, and is different from a pump foamer container that discharges the skin cleansing agent composition in a foam state.

In the present invention, by storing the skin cleansing spray in a spray container in this manner, the skin cleansing spray is directly applied to the skin by spraying, without foaming before application to the skin. This makes it easy to apply to the skin, and avoids physical friction caused by the hands, etc., during application. Examples of spray containers include pump spray containers, which are non-aerosol spray containers, and aerosol spray containers. The aperture (inner diameter of the nozzle) of the spray container is, for example, 0.01 to 3 mmφ, preferably 0.1 to 1 mmφ. When the spray container is a pump spray container, the amount sprayed per push is, for example, 0.05 to 1.2 g, preferably 0.1 to 0.3 g.

Uses The skin cleansing spray of the present invention is used to remove body fluids such as oils and fats, sweat, and dirt from the skin, and is not used as a makeup remover (cleansing). The skin cleansing spray of the present invention is used by applying it directly to the skin without diluting it with water or foaming it. The amount of use per application varies depending on the concentration of the surfactant and the level of dirt, but for example, when used for face washing, it is 0.5 to 3 g, preferably 1 to 2 g.

More specifically, the skin cleaning spray can be applied directly to the area to be cleaned by spraying from a spray container without taking it in the hand. In this way, by directly applying the skin cleaning spray to the area to be cleaned, it is possible to clean only by using the mechanical force of the liquid flow without applying any physical friction such as friction between the skin of the area to be cleaned and the hands, or between the skin of the area to be cleaned and the air bubbles. Since the skin cleaning spray of the present invention is a formulation with excellent cleaning power, by cleaning using the mechanical force of the liquid flow without applying physical friction in this way, the burden on the skin during cleaning is significantly reduced, making it possible to perform an extremely gentle cleaning method. In this way, a cleaning method that does not create foam allows for quick cleaning, and it is easy to realize that the amount of surfactant is small and that it is gentle on the skin, and it is easy to obtain the satisfaction of consumers who are highly conscious of pursuing skin-friendly cleaning. Note that the skin cleaning spray of the present invention is particularly suitable for a cleaning method that does not apply physical friction to the skin as described above, but does not exclude a method of use in which the skin cleaning spray is applied to the area to be cleaned and then scrubbed with hands, etc.

The skin cleansing spray of the present invention can be used to clean any part of the body, and is not particularly limited, and may be used on the hands, hair, scalp, body, face, etc. The skin cleansing spray of the present invention is applied to the part to be cleaned by spraying, and is therefore suitable for use on the hair, scalp, and body from the viewpoint of ease of application. In addition, the skin cleansing spray of the present invention can exert excellent cleaning power without foaming in advance, and is therefore suitable for use on the face, which is sensitive to irritation. Furthermore, the skin cleansing spray of the present invention is preferably used for sensitive skin, since it is low-irritation and has excellent cleaning power. Sensitive skin refers to skin that is chronically or temporarily hypersensitive to specific components of topical agents (e.g., surfactants, preservatives, fragrances, etc.) and ultraviolet rays. Preferred examples of sensitive skin to which the skin cleansing spray of the present invention is applied include skin that has become chronically or temporarily sensitive enough to feel irritation when a skin cleansing spray containing component (A) and not containing component (B) is applied, and particularly includes skin that has become chronically or temporarily sensitive enough to feel irritation when a skin cleansing spray containing, for example, 0.025 to 2% by weight of component (A) and not containing component (B), and adjusted to a pH of 3 to 8, is applied.

After washing, the skin cleansing spray can be washed off with water. When washing off with water, it can be done in the same way as normal face washing, but from the viewpoint of reducing the burden on the skin, it is preferable to wash off using the mechanical force of a water flow without causing friction with the hands.

In addition, since the surfactant concentration of the skin cleansing spray of the present invention can be extremely low, in this case, it is not necessary to rinse it off after cleaning. For this reason, the skin cleansing spray of the present invention is also suitable for use in wiping in hospitals, for skin cleansing treatments such as face washing in beauty salons and hairdressers, and for use as disaster supplies. If it is not rinsed off, the skin cleansing spray remaining on the cleaned area may be absorbed and removed using a water-absorbent substrate such as a towel or tissue.

The skin cleansing spray of the present invention is produced by mixing the aforementioned components (A) and (B) and other components that are added as necessary, preparing the mixture to have a predetermined form and pH, and then storing the mixture in a spray container. When the spray container is an aerosol spray container, the spray container is produced by storing the mixture together with a propellant such as gas.

The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these.

[Reference test example]
Skin cleansing sprays having the compositions shown in Tables 1 to 4 were prepared. Details of each component shown in Tables 1 to 4 are as follows. The skin cleansing sprays shown in Tables 1 to 4 were liquid, and all had a viscosity at 20°C (measured with a BL viscometer (Brookfield B-type viscometer) rotor No. 3 at 6 rpm) in the range of 5000 mPa·s or less, and the pH at 25°C was in the range of 3 to 8 except for Reference Example 1 (pH at 25°C was about 10).
Sodium laurate (NONSAL LN-1 (product name) manufactured by NOF Corporation)
・ TEA-Cocoyl Glutamate ("Amisoft CT-12S (product name)" manufactured by Ajinomoto Co., Inc.)
- Sodium methyl cocoyl taurate ("Diapon K-SF (product name)" manufactured by NOF Corporation)
- Sodium N-lauroyl aspartate solution (20% by weight) ("Aminoformer FLDS-L (product name)" manufactured by Asahi Kasei Fine Chemical Co., Ltd.)
Polyoxyethylene lauryl ether acetic acid ("Kao Akipo RLM-45 (product name)" manufactured by Kao Corporation)
Cocamide DEA ("Amizol CDE-G (product name)" manufactured by Kawaken Fine Chemical Co., Ltd.)
PEG-60 hydrogenated castor oil (polyoxyethylene hydrogenated castor oil; "NIKKOL HCO-60 (product name)" manufactured by Nikko Chemicals Co., Ltd.)
- Polyoxyethylene sorbitan monostearate (Kao Corporation, Rheodor TW-S120V)
Glycerin mono-2-ethylhexyl ether (SEPPIC "Sensiva"
SC 50 JP (product name)”)
Cocamidopropyl betaine ("Softazoline CPB (product name)" manufactured by Kawaken Fine Chemicals Co., Ltd.)
Lauryl hydroxysulfobetaine solution (30% by weight) ("Amphitol 20HD (product name)" manufactured by Kao Corporation)
- Lysolecithin ("Lysolecithin Kyowa (product name)" manufactured by Kyowa Hakko Bio Co., Ltd.)
Quillaja extract ("Quillaja extract BG" manufactured by Maruzen Pharmaceutical Co., Ltd., saponin content 5% by weight)
Cyclohexane-1,4-dicarboxylate bisethoxydiglycol ("Neosolue-Aquilio (product name)" manufactured by Nippon Fine Chemicals Co., Ltd.)
Bisethoxydiglycol succinate ("High Aquostar DCS (product name)" manufactured by Kokyu Alcohol Kogyo Co., Ltd.)

<Cleaning power evaluation>
The prepared skin cleansing sprays were evaluated for their cleansing power by 10 panelists specializing in cosmetic evaluation. Specifically, each skin cleansing spray was placed in a pump-type spray container ("Z-155-C110 (trade name)" manufactured by Takemoto Container Co., Ltd., spray amount per push is 0.15 g), and 1.5 g was applied by spraying directly onto the face. The spray was left for about 5 seconds, and then washed off with water without touching the face with hands. After holding the face with a towel to absorb the water, the feeling of removing dirt from the skin was evaluated by sensory evaluation and scored based on the following index.

5 points: Dirt was thoroughly removed 4 points: Dirt was removed 3 points: Neither 2 points: Dirt was not removed very much 1 point: Dirt was not removed at all

The scores obtained by the 10 panelists were totaled and the degree of cleaning power was evaluated according to the following classification. The results are shown in Tables 1 to 4.
◎: 45 points or more
○: 40 points or more and less than 45 points
△: 35 points or more and less than 40 points
×: Less than 35 points

<Evaluation of tension sensation>
The prepared skin cleansing sprays were evaluated for their feeling of tightness by 10 panelists specializing in cosmetic evaluation. Specifically, each skin cleansing spray was placed in a pump-type spray container ("Z-155-C110 (product name)" manufactured by Takemoto Container Co., Ltd. (amount sprayed per push is 0.15 g) and 1.5 g was applied by spraying directly onto the face. The product was left for about 5 seconds, and then the skin was washed with water without touching the face with the hands. After holding the face with a towel to absorb the water, the feeling of tightness immediately after washing was evaluated by sensory evaluation and scored based on the following index. The stronger the feeling of tightness, the more insufficient moisture was indicated.

5 points: no sense of tension at all 4 points: almost no sense of tension 3 points: only slight sense of tension 2 points: some sense of tension 1 point: strong sense of tension

The scores obtained by the 10 panelists were totaled, and the degree of tightness was evaluated according to the following classification. The results are shown in Tables 3 and 4.
◎: 45 points or more
○: 40 points or more and less than 45 points
△: 35 points or more and less than 40 points
×: Less than 35 points

<Cultured epidermis skin irritation test (in vitro evaluation of skin irritation)>
The prepared skin cleansing spray was subjected to a cultured epidermis skin irritation test as follows.
1. Preparation of cultured epidermis model LabCyte EPI-MODEL24 The assay medium was warmed and added to a 24-well assay plate in 0.5 mL portions. The cultured epidermis model LabCyte EPI-MODEL24 (lot number: LCE24-180226-A) was transferred to the 24-well assay plate to which the assay medium had been added. After confirming that there were no air bubbles on the bottom of the culture cup, the cup was placed in a _CO2 incubator and left to stand for at least 1 hour before exposure to the test substance.

2. Application of test substance and washing Of the 24 epidermal models, 12 were used (the remaining ones were kept in pre-culture until the main test). The 24-well assay plate was removed from the _CO2 incubator. The assay medium was warmed and added to the third row of the 24-well assay plate at 1.0 mL each. The test substance (each skin cleaning spray agent) was dropped at 25 μL onto the cultured epidermis in the culture cup without using a pump-type spray container, and the whole was exposed. After 1 minute, 5 minutes, and 10 minutes of exposure, the test substance was removed by suction, and the cultured epidermis model in the cup was washed with phosphate buffer solution (PBS) and transferred to the third row of the 24-well assay plate.

3. MTT test The MTT test is a method to measure the amount of MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] taken up into cells.
This method measures the cell viability by extracting the formazan dye produced when [H2O3] is reduced by mitochondrial dehydrogenase in the cells with an organic solvent and measuring the absorbance at 570 nm.

10 mL of MTT medium was prepared with a final concentration of 0.5 mg/mL. The MTT medium was warmed and added to the fourth row of a 24-well assay plate in 0.5 mL portions. The cultured epidermis model was transferred to the fourth row of a 24-well assay plate, placed in a CO2 incubator, and subjected to the MTT reaction for 3 hours. After the MTT reaction was completed, the cultured skin was picked up with tweezers and transferred to a 1.5 mL microtube. 300 μL of isopropanol was added to the microtube to completely immerse the cultured epidermis model. After that, the microtube was left to stand for 2 hours, and the microtube was vortexed to extract the pigment. The extract (200 mL) was added to each well of a 96-well plate. In addition, 200 μL of isopropanol was added to A1 as a blank (negative control). The absorbance at 570 nm and 650 nm was measured using a microplate reader. The absorbance at 570 nm minus the absorbance at 650 nm was used as the measured value, and the viability of the test substance was calculated using the following formula.

The cell viability was classified according to the following criteria, and the skin irritation was evaluated. The results are shown in Tables 3 and 4.
◎: 90% or more
○: 75% or more but less than 90%
△: 65% or more but less than 75%
×: 50% or more but less than 65% ××: Less than 50%

As shown in Tables 1 to 4, no cleaning power was observed in the skin cleansing sprays (Reference Comparative Examples 1 to 10) containing a surfactant alone at a concentration of 0.025 to 2% by weight. In contrast, the skin cleansing sprays (Reference Examples 1 to 20) containing an amphiphilic ester (Reference Comparative Examples 11 to 15) that does not show cleaning power alone together with 0.025 to 2% by weight of a surfactant, were able to obtain excellent cleaning power simply by spraying directly onto the skin from a spray container, using the mechanical force of the liquid flow without any physical friction. In other words, it was demonstrated that cleaning that is gentle on the skin is possible.

As shown in Reference Examples 1 to 3, even skin cleansing sprays containing more than 2% by weight of surfactant alone can provide excellent cleansing power simply by spraying them directly onto the skin. On the other hand, taking into consideration the skin irritation caused by the surfactant concentration shown in Reference Examples 1 to 3, when the surfactant concentration was set to 2% by weight or less as shown in Reference Examples 9 to 20, not only was the cleansing power excellent but also low irritation was achieved. In other words, it was shown that by setting the surfactant concentration of the skin cleansing spray to be sprayed directly onto the skin to 0.025 to 2% by weight, it is possible to achieve cleansing that is both physically and chemically gentle on the skin.

[Test Example]
Skin cleansing sprays were prepared with the compositions shown in Tables 5 and 6. Details of each component shown in Tables 5 and 6 are as shown in the Reference Test Examples. The skin cleansing sprays shown in Tables 5 and 6 had a viscosity of 5000 mPa·s or less at 20°C (measured with a BL viscometer (Brookfield B-type viscometer) rotor No. 3 at 6 rpm).

<pH measurement>
The pH of each of the prepared skin cleansing compositions was measured at 25° C. using a HORIBA benchtop pH meter (F-72).

<Cleaning power evaluation>
The prepared skin cleansing compositions were evaluated for their detergency in the same manner as in the Reference Test Examples, and the results are shown in Tables 5 and 6.

<Irritation sensation evaluation>
The prepared skin cleansing compositions were subjected to an irritation evaluation by 10 panelists specializing in cosmetic evaluation. Specifically, each skin cleansing composition was placed in a pump-type spray container ("Z-155-C110 (product name)" manufactured by Takemoto Container Co., Ltd. (amount sprayed per push is 0.15 g) and 1.5 g was applied by spraying directly onto the entire body. The composition was left for about 5 seconds, and then washed with water without touching the skin with the hands. The skin was held down with a towel to absorb the water, and the irritation was scored by sensory evaluation based on the following criteria.

5 points: No irritation felt at all 4 points: Little irritation felt 3 points: Slight irritation felt 2 points: Irritation felt 1 point: Strong irritation felt

The scores obtained by the 10 panelists were totaled and the degree of irritation was evaluated according to the following classification. The results are shown in Tables 5 and 6.
◎: 45 points or more
○: 40 points or more and less than 45 points
△: 35 points or more and less than 40 points
×: Less than 35 points

<Evaluation of tension sensation>
The degree of the feeling of tightness was evaluated in the same manner as in the Reference Test Example, except that the evaluation of the feeling of tightness was performed not only immediately after washing, but also 5 minutes and 10 minutes after washing. The results are shown in Tables 5 and 6.

As shown in Tables 5 and 6, in the skin cleansing sprays (Examples 1 to 15) containing 2% by weight of surfactant, amphipathic ester, and pH adjusted to 3 to 8, it was found that excellent cleansing power could be obtained simply by spraying directly onto the skin from a spray container, without any physical friction, and by utilizing the mechanical force of the liquid flow. In addition, in the skin cleansing sprays (Comparative Examples 1 to 5) containing 2% by weight of surfactant and amphipathic ester, but with a pH below 3, irritation was increased, and depending on the type of surfactant, reduced cleansing power and increased tightness due to insufficient moisturization were observed, while in the skin cleansing sprays (Comparative Examples 6 to 10) with a pH above 8, increased tightness due to insufficient moisturization were observed, and depending on the type of surfactant, increased irritation and reduced cleansing power were observed.

Claims (7)

A skin cleansing spray agent containing (A) an anionic surfactant, a nonionic surfactant, an amphoteric surfactant, and/or a natural surfactant, and (B) an amphiphilic ester selected from the group consisting of a dicarboxylate bis(polyoxyalkylene alkyl ether) ester, a dicarboxylate dialkoxyalkyl ester, and polyglyceryl-10 (eicosadioate/tetradecanedioate), having a pH of 3 to 8, and contained in a spray-type container that is not a pump foamer container and discharges in a foam state,
It is used to spray directly onto the hands, body, or face, and to cleanse using the mechanical force of the liquid flow , and then to rinse with water or to absorb and remove the skin cleansing spray remaining on the cleansed area using a water-absorbent substrate; and
A skin cleansing spray that is not to be used as a makeup remover. A skin cleansing spray agent containing (A) a surfactant as a cleansing component and (B) an amphiphilic ester selected from the group consisting of a dicarboxylate bis(polyoxyalkylene alkyl ether) ester, a dicarboxylate dialkoxyalkyl ester, and polyglyceryl-10 (eicosadioate/tetradecanedioate), having a pH of 3 to 8, and contained in a spray-type container that is not a pump foamer container and discharges the agent in a foam state,
It is used to spray directly onto the hands, body, or face, and to cleanse using the mechanical force of the liquid flow , and then to rinse with water or to absorb and remove the skin cleansing spray remaining on the cleansed area using a water-absorbent substrate; and
A skin cleansing spray that is not to be used as a makeup remover. The skin cleansing spray according to claim 1 or 2, wherein the spray container is a pump-type spray container. The skin cleansing spray according to claim 1 or 2, wherein the spray container is an aerosol spray container. The skin cleansing spray according to any one of claims 1 to 4, wherein the dicarboxylic acid bis(polyoxyalkylene alkyl ether) ester is cyclohexane-1,4-dicarboxylate bisethoxydiglycol. The skin cleansing spray according to any one of claims 1 to 5, wherein the content of component (A) is 0.025 to 2% by weight. The skin cleansing spray according to any one of claims 1 to 6, which is applied to sensitive skin.