Skin cleanser

Abstract

A skin cleanser according to the present invention is used as a foam discharged from a non-aerosol foam container. The cleanser contains components (A), (B), and (C). (A) is anionic surfactant, 1 to 20 mass%; (B) is polysaccharide, 0.05 to 0.7 mass%; and (C) is water, 80 mass% or less. The ratio between viscosity v1 and viscosity v2 (v2 / v1) is at least 700, the viscosity v1 and the viscosity v2 each being the viscosity of 1 mass% aqueous solution of the polysaccharide, v1 being at a shear speed of 1.0×103 (s-1) and v2 being at a shear speed of 1.0x10-1 (s-1).

Description

Skin cleanser

[0001] The present invention relates to a skin cleanser.

[0002] Skin cleansing agents that are filled into foam-dispensing containers and discharged as fine foam have the advantages of not only eliminating the need for lathering but also reducing irritation to the skin due to the creamy foam quality, etc. It is desirable for such cleansing agents to produce abundant, elastic foam when discharged from the container.

[0003] In general, thickeners such as water-soluble polymers are used in compositions such as skin cleansers to improve the quality of foam after lathering. For example, Patent Document 1 describes that a cleanser containing an anionic surfactant and a water-soluble polymer exhibiting thixotropy does not increase the pressing pressure and significantly improves the denseness and elasticity of the foam discharged from a foamer container. Patent Document 2 describes a foam-discharged aqueous gel skin cleanser that contains an anionic surfactant, gellan gum, and xanthan gum and has a viscosity of 1,000 to 6,000 cps at 25°C, and that can produce elastic, thick, and long-lasting foam.

[0004] JP 2020-90488 A Patent No. 5745945 A

[0005] However, Patent Document 1 does not pay attention to the thickness of the foam that is ejected. Furthermore, when the amount of water-soluble polymer is increased to increase the viscosity, uneven and large bubbles are formed, which inevitably leads to a deterioration in the foam appearance. Patent Documents 1 and 2 do not state anything about ejecting fine foam and not causing clogging over time. At present, a cleanser that has excellent foam performance, such as foam elasticity and foam thickness, and also has good ejection properties, such as foam appearance, pump pressure, and clogging, has not yet been obtained.

[0006] The inventors of the present invention have conducted extensive research focusing on the shear force applied to the cleanser when it is discharged from a foamer container, and have found that by combining a polysaccharide exhibiting specific viscosity characteristics with an anionic surfactant in the cleanser, it is possible to increase foam elasticity while suppressing pressure, thereby achieving both excellent foam performance and good dischargeability.

[0007] The present invention relates to a composition comprising the following components (A), (B), and (C): (A) an anionic surfactant, 1 to 20% by mass; (B) a 1% by mass aqueous solution of an anionic surfactant, the viscosity of which is such that the viscosity of the anionic surfactant ... ３ (s －１ ) and viscosity v1 at a shear rate of 1.0 × 10 －１ (s －１ (C) 0.05 to 0.7% by mass of a polysaccharide having a viscosity v1 / v2 ratio (v2 / v1) of 700 or more, and (D) 80% by mass or less of water, and the skin cleanser is used by being discharged in the form of foam from a non-aerosol foamer container.

[0008] According to the skin cleanser of this embodiment, foam performance such as foam elasticity and foam thickness can be improved without impairing discharge properties such as foam appearance, pump pressure, and clogging.

[0009] The skin cleanser of this embodiment is used by being discharged in the form of foam from a non-aerosol foamer container, and contains an anionic surfactant (foaming surfactant) as component (A). The anionic surfactant of component (A) is not limited as long as it is one that is commonly used in cleansers, and examples thereof include carboxylic acid surfactants such as fatty acid salts and alkyl ether carboxylates; sulfate esters such as alkyl sulfates and alkyl ether sulfates; sulfonates such as sulfosuccinate alkyl ester salts, polyoxyalkylene sulfosuccinate alkyl ester salts, α-olefin sulfonates and hydroxyalkanesulfonates; N-acylamino acid salts and N-acylalkyltaurine salts.

[0010] Among these, from the viewpoints of foaming ability and foam quality, it is preferable to contain at least one selected from fatty acid salts, alkyl ether carboxylates, N-acylamino acid salts, alkyl ether sulfates, and sulfonates. In particular, from the viewpoint of improving foam quality, it is preferable to contain a fatty acid salt. Furthermore, from the viewpoints of improving detergency and reducing irritation to the skin in addition to foaming ability and foam quality, it is preferable to contain an alkyl ether carboxylate, and it is more preferable to contain both a fatty acid salt and an alkyl ether carboxylate.

[0011] From the viewpoint of improving foaming and rinsing properties, the fatty acid in the fatty acid salt preferably has a linear or branched alkyl or alkenyl group having 9 to 21 carbon atoms. From the same viewpoint, the number of carbon atoms in the group is preferably 11 to 21, more preferably 11 to 17, and even more preferably 11 to 15. From the same viewpoint, the group is preferably an alkyl group, and more preferably a linear alkyl group.

[0012] Specifically, one or more selected from lauric acid, myristic acid, palmitic acid, stearic acid, and behenic acid may be used. Among these, from the same viewpoint as above, it is preferable to include one or more selected from lauric acid, myristic acid, and palmitic acid, and it is more preferable to include one or two selected from lauric acid and myristic acid.

[0013] Components that react with fatty acids to form their salts include alkali metals such as sodium and potassium; alkaline earth metals such as calcium and magnesium; ammonium (NH ４ ＋ organic ammonium compounds such as monoethanolamine, diethanolamine, triethanolamine, AMP (2-amino-2-methyl-1-propanol), and 2-amino-2-hydroxymethyl-1,3-propanediol; and basic amino acids such as L-arginine. Of these, alkali metals are preferred from the viewpoint of improving foaming and rinsing properties.

[0014] Examples of alkyl ether carboxylates include those represented by general formula (1).

[0015]

[0016] (In the formula, R １ represents an alkyl or alkenyl group having 8 to 20 carbon atoms, n represents the average number of moles of ethylene oxide added, which is an average of 0.5 to 10, X represents an alkali metal, an alkaline earth metal, or ammonium (NH ４ ＋ ), organic ammonium or basic amino acid.

[0017] In general formula (1), R １From the viewpoint of improving detergency, foaming, and rinsing properties, R preferably has 10 to 18 carbon atoms, and more preferably 12 to 16 carbon atoms. １ is preferably an alkyl group, more preferably a linear alkyl group. From the same viewpoint, the average number of moles of ethylene oxide added, n, is preferably 1 to 6. X may be an alkali metal such as sodium or potassium; an alkaline earth metal such as calcium or magnesium; ammonium (NH ４ ＋ organic ammonium compounds such as monoethanolamine, diethanolamine, triethanolamine, AMP (2-amino-2-methyl-1-propanol), and 2-amino-2-hydroxymethyl-1,3-propanediol; and basic amino acids such as L-arginine. Of these, alkali metals are preferred from the viewpoint of improving foaming and rinsing properties.

[0018] Specifically, from the same viewpoint as above, the composition preferably contains one or more selected from polyoxyethylene lauryl ether carboxylate, polyoxyethylene myristyl ether carboxylate, and polyoxyethylene palmityl ether carboxylate, more preferably contains one or two selected from polyoxyethylene lauryl ether carboxylate and polyoxyethylene myristyl ether carboxylate, and even more preferably contains polyoxyethylene lauryl ether carboxylate. Commercially available products of such ether carboxylic acids or salts thereof include AKYPO RLM 45CA (manufactured by Kao Corporation) and AKYPO LM 26C (manufactured by Kao Corporation).

[0019] From the viewpoint of foaming properties and the like, the N-acylamino acid salt is preferably one in which the acyl group is derived from a saturated or unsaturated, straight-chain or branched fatty acid having 8 to 18 carbon atoms, more preferably one in which the acyl group is derived from a saturated or unsaturated, straight-chain or branched fatty acid having 8 to 16 carbon atoms, and even more preferably one in which the acyl group is derived from a saturated or unsaturated, straight-chain or branched fatty acid having 8 to 14 carbon atoms.

[0020] Examples of such fatty acids include caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, and oleic acid. Among these fatty acids, from the viewpoints of foam quality and storage stability, lauric acid, myristic acid, palmitic acid, and oleic acid are preferred, with lauric acid being more preferred. The acyl group of the N-acylamino acid may be derived from a mixed fatty acid of the above-mentioned fatty acids, for example, one obtained using coconut oil, palm kernel oil, or the like as a raw material. Among these, those obtained using coconut oil fatty acid or palm kernel fatty acid as a raw material are preferred, and those obtained using coconut oil fatty acid as a raw material are more preferred.

[0021] From the viewpoints of foam quality and a pleasant feel after washing, such as soft, moist skin, the amino acid moiety in the N-acylamino acid salt is preferably a neutral amino acid selected from glycine and alanine, or an acidic amino acid selected from glutamic acid and aspartic acid, more preferably an acidic amino acid, and even more preferably glutamic acid. These amino acid moieties may be in the D-form, the L-form, or a mixture of the D- and L-forms, with the L-form being preferred.

[0022] From the viewpoint of foam quality and the like, the N-acylamino acid is preferably N-lauroyl glutamic acid, N-myristoyl glutamic acid, N-cocoyl glutamic acid, N-palm fatty acid glutamic acid, N-lauroylaspartic acid, N-cocoyl glycine, or N-cocoyl alanine; more preferably N-lauroyl glutamic acid, N-myristoyl glutamic acid, N-cocoyl glutamic acid, N-palm fatty acid glutamic acid, N-lauroylaspartic acid, or N-cocoyl glycine; even more preferably N-lauroyl glutamic acid, N-myristoyl glutamic acid, N-cocoyl glutamic acid, or N-lauroylasparagine; even more preferably N-cocoyl glutamic acid or N-lauroylaspartic acid; and particularly preferably N-cocoyl glutamic acid.

[0023] Furthermore, from the viewpoint of ensuring foaming and foam quality, examples of N-acylamino acid salts include alkali metal salts such as sodium and potassium; alkaline earth metal salts such as calcium and magnesium; other inorganic salts such as aluminum and zinc; ammonium salts; organic amine salts such as monoethanolamine, diethanolamine, triethanolamine, AMP (2-amino-2-methyl-1-propanol), and 2-amino-2-hydroxymethyl-1,3-propanediol; and other organic salts such as basic amino acid salts of arginine, lysine, histidine, and ornithine. From the viewpoint of skin irritation, alkali metal salts, triethanolamine salts, and arginine salts are preferred, sodium salts, potassium salts, triethanolamine salts, and arginine salts are more preferred, sodium salts and potassium salts are even more preferred, and sodium salts are even more preferred.

[0024] The alkyl ether sulfate includes those represented by the general formula (2).

[0025]

[0026] (In the formula, R ２ represents an alkyl or alkenyl group having 8 to 22 carbon atoms, m represents the average number of moles of ethylene oxide added and is a number from 0 to 20, and Y represents an alkali metal, alkaline earth metal, or ammonium (NH ４ ＋ ) or organic ammonium.

[0027] In general formula (2), R ２ is an alkyl or alkenyl group having 8 to 22 carbon atoms, and may be either a straight chain or a branched chain. ２ is preferably an alkyl group, more preferably having 12 to 18 carbon atoms, and even more preferably having 12 to 14 carbon atoms. m is preferably 0 to 12. Examples of Y include the same as X in the alkyl ether carboxylate of general formula (1) above.

[0028] Specifically, from the same viewpoint as above, examples thereof include one or more selected from polyoxyethylene (1) lauryl ether sodium sulfate, polyoxyethylene (1) lauryl ether ammonium sulfate, polyoxyethylene (1) myristyl ether sodium sulfate, polyoxyethylene (2) lauryl ether sodium sulfate, and polyoxyethylene (2) myristyl ether sodium sulfate. Among these, it is preferable to include one or more selected from polyoxyethylene (1) lauryl ether sodium sulfate, polyoxyethylene (1) lauryl ether ammonium sulfate, and polyoxyethylene (2) lauryl ether sodium sulfate.

[0029] In this specification, the numerical values ​​in parentheses for these compounds mean the average number of moles of ethylene oxide added. Commercially available alkyl ether sulfates include EMALE 125HP (manufactured by Kao Corporation, polyoxyethylene (1) lauryl ether sodium sulfate), EMALE 125A (manufactured by Kao Corporation, polyoxyethylene (1) lauryl ether ammonium sulfate), and EMALE 227 (manufactured by Kao Corporation, polyoxyethylene (2) lauryl ether sodium sulfate).

[0030] Examples of sulfonates include alkyl sulfonates and alkenyl sulfonates.

[0031] The alkyl group constituting the alkyl sulfonate is preferably a hydroxyalkyl sulfonic acid or salt thereof having 12 to 22 carbon atoms, more preferably a hydroxyalkyl sulfonic acid or salt thereof in which a sulfo group is bonded to any carbon atom except the terminal carbon atom, and even more preferably a hydroxyalkyl sulfonic acid or salt thereof having 12 to 18 carbon atoms in which a sulfo group is bonded to any carbon atom except the terminal carbon atom. Even more preferably, a hydroxyalkyl sulfonic acid or salt thereof is a linear hydrocarbon having 12 to 18 carbon atoms in which a hydroxyl group is bonded to any carbon atom except the terminal carbon atom and a sulfo group is bonded to any carbon atom except the terminal carbon atom.

[0032] These hydroxyalkyl sulfonic acids or salts thereof having 12 to 22 carbon atoms may be used alone or in combination of two or more. From the viewpoint of being able to control foaming ability and foam quality, it is preferable to use a combination of two or more depending on the purpose of use. Furthermore, from the viewpoint of foaming ability and foam quality, a hydroxyalkyl sulfonic acid or salt thereof having 16 carbon atoms, or a hydroxyalkyl sulfonic acid or salt thereof having 18 carbon atoms, is preferred. Furthermore, it is preferable to use a mixture of a hydroxyalkyl sulfonic acid or salt thereof having 16 carbon atoms and a hydroxyalkyl sulfonic acid or salt thereof having 18 carbon atoms, and in this case, the mass ratio of the hydroxyalkyl sulfonic acid or salt thereof having 16 carbon atoms to the hydroxyalkyl sulfonic acid or salt thereof having 18 carbon atoms (hydroxyalkyl sulfonic acid or salt thereof having 16 carbon atoms / hydroxyalkyl sulfonic acid or salt thereof) is preferably 9 / 1 to 1 / 9, more preferably 8 / 2 to 2 / 8, and even more preferably 5 / 5 to 2 / 8. The use of these mixtures can improve the feel during rinsing.

[0033] Examples of salts constituting alkylsulfonates include salts formed from alkali metals such as sodium and potassium, alkaline earth metals such as calcium and magnesium, ammonium, and organic ammonium salts such as monoethanolamine, diethanolamine, triethanolamine, AMP (2-amino-2-methyl-1-propanol), 2-amino-2-hydroxymethyl-1,3-propanediol, etc. Of these, alkali metal salts and ammonium salts are preferred from the viewpoint of commercial availability.

[0034] The alkenyl sulfonic acid or salt thereof is preferably a straight-chain hydrocarbon having 12 to 22 carbon atoms and a double bond, and more preferably an alkenyl sulfonic acid or salt thereof that is a straight-chain hydrocarbon having 12 to 18 carbon atoms and a double bond, in which a sulfo group is bonded to any carbon atom except the terminal carbon atom. Even more preferably, the alkenyl sulfonic acid or salt thereof is a straight-chain hydrocarbon having 12 to 18 carbon atoms and a double bond, in which 70% or more of the double bonds are located at positions 3 or higher internally in the straight-chain hydrocarbon, and in which a sulfo group is bonded to any carbon atom except the terminal carbon atom. These alkenyl sulfonic acids or salts thereof having 12 to 22 carbon atoms may be used alone or in combination of two or more. From the viewpoint of being able to control foaming ability and foam quality, it is preferable to use a combination of two or more depending on the purpose of use.

[0035] Furthermore, from the viewpoint of foaming ability and foam quality, C16 alkenyl sulfonic acids or salts thereof, or C18 alkenyl sulfonic acids or salts thereof are preferred. Also, it is preferable to use a mixture of C16 alkenyl sulfonic acids or salts thereof and C18 alkenyl sulfonic acids or salts thereof, in which case the mass ratio of C16 alkenyl sulfonic acids or salts thereof to C18 alkenyl sulfonic acids or salts thereof is preferably 1 / 9 to 9 / 1, more preferably 2 / 8 to 8 / 2, and even more preferably 5 / 5 to 2 / 8. Use of such a mixture can improve the feel during rinsing.

[0036] Examples of salts constituting the alkenyl sulfonate include salts formed from alkali metals such as sodium and potassium, alkaline earth metals such as calcium and magnesium, ammonium, and organic ammonium salts such as monoethanolamine, diethanolamine, triethanolamine, AMP (2-amino-2-methyl-1-propanol), 2-amino-2-hydroxymethyl-1,3-propanediol, etc. Of these, alkali metal salts and ammonium salts are preferred from the viewpoint of commercial availability.

[0037] Either an alkenyl sulfonic acid or a salt thereof, or an alkyl sulfonic acid or a salt thereof may be used, or a mixture of these alkenyl sulfonic acids or salts thereof and alkyl sulfonic acids or salts thereof may be used. When a mixture of these is used, the mass ratio of the alkenyl sulfonic acid or a salt thereof to the alkyl sulfonic acid or a salt thereof (alkenyl sulfonic acid or a salt thereof / alkyl sulfonic acid or a salt thereof) is preferably 5 / 95 to 50 / 50, and more preferably 10 / 90 to 30 / 70. The alkenyl sulfonic acid or a salt thereof, and the alkyl sulfonic acid or a salt thereof can be produced, for example, by the method described in JP 2015-28123 A.

[0038] Component (A) may be used alone or in combination of two or more. From the viewpoints of foam elasticity during ejection and foam thickness during cleansing, the content of component (A) in the skin cleanser is preferably 1% by mass or more, and more preferably 3% by mass or more. From the viewpoint of ejection performance, the content of component (A) in the skin cleanser is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less. The content of component (A) in the skin cleanser is preferably 1 to 20% by mass, more preferably 3 to 15% by mass, and even more preferably 3 to 10% by mass.

[0039] The polysaccharide of component (B) acts as a thickener, and when prepared as a 1% by mass aqueous solution, it thickens at a shear rate of 1.0 x 10 ３ (s －１ ) and viscosity v1 at a shear rate of 1.0 × 10 －１ (s －１ The ratio of v2 / v1 to the viscosity v2 at the viscosity v1 at the time of discharge is preferably 700 or more. From the viewpoints of foam appearance during discharge and ease of pumping, v2 / v1 is preferably 800 or more, and more preferably 900 or more.

[0040] Here, the viscosity was measured by setting a 1% by mass aqueous solution of component (B) in a rheometer, leaving it to stand for 5 minutes, and then measuring the viscosity at a shear rate of 0.1 to 1,000 s －１ / Measurement time: (9-2) s, the value obtained by measurement at 30° C. More specifically, the measurement is performed under the following conditions.

[0041] (Measurement equipment) MCR302, Modular Compact Rheometer, Anton Paar Measuring Cell: P-PTD200 Measuring System: CP75-1 / Ti, d=0.041 (Measurement conditions) A 1% by mass aqueous solution of component (B) was placed between plates and allowed to stand for 5 minutes, after which the shear rate was adjusted to 0.1-1000 s －１ / Measurement time: (9-2) s, measured at 30 ° C. That is, shear rate: 0.1 s －１ When the measurement time is 9 seconds, the shear rate is 1000 seconds. －１ The viscosity is measured by changing the shear rate and the measurement time, for example, by setting the measurement time to 2 seconds when the shear rate is 100%.

[0042] Component (B) having the viscosity characteristics described above can be said to be a polysaccharide with pseudoplastic properties. Even when the viscosity of the skin cleansing liquid is increased, the viscosity at the time of ejection is sufficiently reduced, making it possible to obtain uniform bubbles while maintaining a low pressure. In other words, compared to when the viscosity is increased using conventional water-soluble polymers with thixotropy, a high viscosity and high foam elasticity can be achieved.

[0043] It is believed that pseudoplastic polysaccharides exert a thickening effect by entangling their large molecular chains, and that under high shear stress, the entanglement of the molecular chains is dissociated, resulting in a decrease in viscosity. By using such polysaccharides in combination with component (A), it has become possible to suppress an increase in the pressing pressure of the former, even though the foam is thick and resistant to collapse after being discharged from the former.

[0044] Component (B) has a viscosity v1 of, for example, 20 to 50 mPa·s, and a viscosity v2 of, for example, 20,000 to 70,000 mPa·s. Component (B) is not particularly limited as long as the viscosity ratio (v2 / v1) is 700 or greater, and at least one selected from the group consisting of xanthan gum, cationized xanthan gum, diutan gum, and welan gum can be used. Among these polysaccharides, xanthan gum and cationized xanthan gum are more preferred from the viewpoints of foam elasticity during discharge, foam appearance during discharge, ease of pumping, foam thickness during cleaning, and the possibility of clogging.

[0045] Specific examples of component (B) include commercially available products such as Echo Gum T (Sumitomo Pharma Food & Chemical Co., Ltd.), Echo Gum (Sumitomo Pharma Food & Chemical Co., Ltd.), Keldent (Sumitomo Pharma Food & Chemical Co., Ltd.), Keldent SFT (Sumitomo Pharma Food & Chemical Co., Ltd.), Nomcoat ZZ (The Nisshin Oillio Group, Ltd.), San Ace C (Sanei Gen F.F.I. Inc.), Labol Gum CX (Sumitomo Pharma Food & Chemical Co., Ltd.), KELKO-CARE Diutan Gum (The Lubrizol Corporation), and Welan Gum BG3810 (Sansho Corporation).

[0046] Component (B) may be used alone or in combination of two or more. From the viewpoints of foam elasticity during discharge and foam thickness during cleansing, the content of component (B) in the skin cleanser is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.3% by mass or more. From the viewpoints of foam appearance during discharge, ease of pump depression, foam thickness during cleansing, and the possibility of clogging, the content of component (B) is preferably 0.7% by mass or less, more preferably 0.5% by mass or less, and even more preferably 0.3% by mass or less. The content of component (B) in the skin cleanser is preferably 0.05 to 0.7% by mass, more preferably 0.1 to 0.5% by mass, and even more preferably 0.1 to 0.3% by mass.

[0047] In this embodiment, the mass ratio (A) / (B) of component (A) to component (B) is preferably 100 or less, more preferably 50 or less, and even more preferably 20 or less, from the viewpoints of the possibility of clogging, foam appearance, foam elasticity during discharge, and foam thickness during cleaning. Furthermore, from the viewpoints of the foam appearance during discharge, ease of pumping, foam thickness during cleaning, and the possibility of clogging, it is preferably 5 or more, more preferably 7 or more, and even more preferably 10 or more. Furthermore, the mass ratio (A) / (B) of component (A) to component (B) is preferably 5 to 100, more preferably 7 to 50, and even more preferably 10 to 20.

[0048] In this embodiment, the content of water in component (C), which is the remainder of components (A) and (B) and other components contained as necessary, is specified to be 80% by mass or less. A water content of 80% by mass or less can also suppress clogging. From the viewpoint of the possibility of clogging, the water content is preferably 80% by mass or less. Furthermore, from the viewpoints of foam appearance upon discharge, ease of pumping, and foam thickness upon washing, the water content in the skin cleanser is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more. Furthermore, the water content in the skin cleanser is preferably 50 to 80% by mass, more preferably 60 to 80% by mass, and even more preferably 70 to 80% by mass.

[0049] The skin cleanser of this embodiment preferably further contains a humectant (D) from the viewpoint of further improving the density of the foam after discharge from the foamer container through the synergistic effect of components (A) and (B). A polyol that is liquid at 25°C can be used as the humectant. Examples of polyols that are liquid at 25°C include ethylene glycol, diethylene glycol, hexylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, isoprene glycol, 1,3-butylene glycol, 1,3-propanediol, glycerin, diglycerin, triglycerin, tetraglycerin, hexaglycerin, and decaglycerin trimethylpropanol. Among these, from the viewpoints of foaming and the dense feel of the discharged foam, dihydric or trihydric alcohols are preferred, and propylene glycol and glycerin are more preferred.

[0050] The moisturizing agent of component (D) may be used alone or in combination of two or more. From the viewpoints of foam elasticity, foam thickness, and suppressing the possibility of clogging, the content of component (D) in the skin cleanser is preferably 10% by mass or more, and more preferably 15% by mass or more. Furthermore, from the viewpoints of foam appearance upon discharge, ease of pumping, and foam thickness upon cleansing, the content is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less. Furthermore, the content of component (D) in the skin cleanser is preferably 10 to 40% by mass, more preferably 15 to 30% by mass, and even more preferably 20 to 30% by mass.

[0051] From the viewpoint of foaming, the skin cleanser of this embodiment may further contain an amphoteric surfactant as component (E). Examples of amphoteric surfactants include alkyl sulfobetaines, alkylhydroxysulfobetaines, alkylcarbobetaines, alkylamidohydroxysulfobetaines, alkylamidoamine-type betaines, and alkylimidazoline-type betaines. Here, the number of carbon atoms in the alkyl group of the amphoteric surfactant is preferably 8 to 20, and more preferably 8 to 14.

[0052] Among these, from the viewpoint of foam thickness during washing, the amphoteric surfactant can be selected from alkylamidopropylbetaine having an alkyl group having 8 to 14 carbon atoms and alkylhydroxysulfobetaine, with alkylhydroxysulfobetaine being more preferred and laurylhydroxysulfobetaine being even more preferred.

[0053] The amphoteric surfactant may be used alone or in combination of two or more. From the viewpoint of foam thickness during cleansing, the content of the amphoteric surfactant in the skin cleanser is preferably 0.1% by mass or more, more preferably 0.5% by mass or more. From the same viewpoint, it is preferably 3% by mass or less, more preferably 1% by mass or less. The content of the amphoteric surfactant in the skin cleanser is preferably 0.1 to 3% by mass, more preferably 0.5 to 1% by mass.

[0054] In addition to the above-mentioned components, the skin cleanser of this embodiment may contain components commonly used in ordinary cleansers to the extent that the effects of this embodiment are not impaired. Examples include surfactants other than those mentioned above, lower alcohols such as ethanol and isopropyl alcohol, aromatic alcohols such as benzyl alcohol and benzyloxyethanol, cellosolves such as ethyl cellosolve and butyl cellosolve, carbitols such as ethyl carbitol and butyl carbitol, moisturizing ingredients such as sugar (derivatives), amino acid (derivatives), animal and plant (protein) derivatives, and animal and plant extracts, silicone derivatives such as polyoxyalkylene-modified silicone, inorganic or organic salts such as sodium sulfate, sodium carbonate, sodium bicarbonate, potassium chloride, sodium chloride, and sodium citrate, pH adjusters such as acids and alkalis, anti-inflammatory agents such as glycyrrhetinic acid, glycyrrhizinic acid, and derivatives thereof, disinfectants such as isopropylmethylphenol, preservatives, sequestering agents, antioxidants, ultraviolet absorbers, fragrances, vitamins, natural pigments such as chlorophyll and β-carotene, and colorants such as tar pigments.

[0055] From the viewpoints of ensuring a good feel during use and maintaining low irritation to the skin, the pH of the skin cleanser of this embodiment is preferably in the range of pH 5 to 11, and more preferably pH 6 to 10. The pH of the skin cleanser is measured using a pH electrode for the undiluted solution at 30°C.

[0056] The skin cleanser of this embodiment is liquid, and from the viewpoints of foam elasticity upon discharge, foam appearance upon discharge, ease of pumping, and foam thickness upon cleansing, the viscosity at 30°C is preferably 10 to 4000 mPa·s, more preferably 20 to 2000 mPa·s, and even more preferably 100 to 1000 mPa·s. Furthermore, from the viewpoints of foam appearance upon discharge, ease of pumping, and foam thickness upon cleansing, the viscosity is preferably 4000 mPa·s or less, more preferably 2000 mPa·s or less, and even more preferably 1000 mPa·s or less. Furthermore, particularly from the viewpoints of foam elasticity upon discharge and foam thickness upon cleansing, the viscosity is preferably 10 mPa·s or more, more preferably 20 mPa·s or more, and even more preferably 100 mPa·s or more.

[0057] In this embodiment, the viscosity of the skin cleanser is measured at 30°C using a Brookfield viscometer (TVB-10 viscometer, manufactured by Toki Sangyo Co., Ltd.). Viscosities of less than 100 mPa·s are measured with rotor No. 1 (rotation speed) at 60 rpm, viscosities of 100 to 199 mPa·s are measured with rotor No. 1 (rotation speed) at 30 rpm, viscosities of 200 to 499 mPa·s are measured with rotor No. 1 (rotation speed) at 12 rpm, viscosities of 500 to 2499 mPa·s are measured with rotor No. 2 (rotation speed) at 12 rpm, and viscosities of 2500 mPa·s or higher are measured with rotor No. 3 (rotation speed) at 12 rpm.

[0058] The skin cleanser of this embodiment is filled in a non-aerosol foamer container. Any non-aerosol foamer container can be used as long as it can mix the skin cleanser with air and discharge it as foam, but examples include pump foamer containers that discharge the skin cleanser by pressing a pump head. Specifically, foamer containers described in Japanese Patent Nos. 7223643, 7193999, 7221031, etc. can be used.

[0059] Among these, from the viewpoints of convenience in the environment in which the skin cleanser is used and of obtaining a dense and elastic foam, a pump foamer container that discharges by pressing the pump head is preferred, and from the viewpoint of further improving the foam quality, a pump foamer container equipped with a porous membrane filter in the discharge flow path is more preferred. From the viewpoint of obtaining a finer and better foam quality, such a porous membrane filter is preferably a 90 to 400 mesh filter, more preferably a 200 to 400 mesh filter, and even more preferably a 200 to 305 mesh filter. Preferably, one to three such porous filters are arranged in the discharge flow path, and more preferably two filters are arranged.

[0060] Pump former containers have a complex driving mechanism and are easily affected by pressure. The skin cleanser of this embodiment is a liquid composition containing an anionic surfactant as a foaming surfactant, a predetermined polysaccharide, and water in predetermined ratios. Therefore, even when stored in a non-aerosol foamer container such as a pump former container, an increase in pressure can be suppressed and dense, highly elastic foam can be ejected. Regarding the mixing ratio of the skin cleanser to air in the pump former container, for example, from the viewpoint of obtaining a good amount of foam and foam quality that makes it easy to wash the skin, the density of the ejected foam (mass of skin cleanser / volume of air) is set to 0.03 to 0.14 g / cm. ３ Preferably, it is 0.05 to 0.11 g / cm ３ is more preferred.

[0061] The skin cleanser of this embodiment is preferably used as a skin cleanser in a non-aerosol foam container, and among skin cleansers, it is preferably used as a hand soap, facial cleanser, or body soap. The skin cleanser of this embodiment can be used to cleanse the skin using a common skin cleansing method. For example, the foam discharged from the non-aerosol foam container can be taken into the hands, applied directly to the skin as is without diluting with water, lathered to cleanse, and then rinsed with warm water from a shower or the like. Alternatively, the foam discharged from the container can be taken into the hands and spread directly on the skin with the hands to cleanse.

[0062] Furthermore, methods for cleansing the skin include washing with the hands, as well as washing with a sponge, towel, scrubbing brush, or the like made of chemical fibers such as cotton or nylon. However, from the viewpoint of reducing irritation to the skin and effectively exerting foam performance and a feeling of use, the method of taking the foam directly into the hands and washing the skin with the hands is preferred.

[0063] While the preferred embodiments of the present invention have been described above, the technical scope of the present invention is not limited to the scope of the above-described embodiments. Various modifications and improvements can be made to the above-described embodiments.

[0064] In relation to the above-mentioned embodiment, the present invention further discloses the following skin cleanser.

[0065] <1> The following components (A), (B), and (C): (A) an anionic surfactant 1 to 20 mass %; (B) a 1 mass % aqueous solution with a viscosity of 1.0 x 10 at a shear rate of 1.0 x 10 ３ (s －１ ) and viscosity v1 at a shear rate of 1.0 × 10 －１ (s －１(C) 0.05 to 0.7% by mass of a polysaccharide having a viscosity v1 / v2 ratio (v2 / v1) of 700 or more and (D) 80% by mass or less of water, said skin cleanser being dispensed in the form of foam from a non-aerosol foamer container. <2> The skin cleanser according to <1>, wherein the (A) anionic surfactant contains at least one selected from laureth 6-carboxylic acid, laureth 4-carboxylic acid, sodium cocoyl glutamate, polyoxyethylene sodium lauryl sulfate, and an internal olefin sulfonate composition. <3> The skin cleanser according to <1> or <2>, wherein the (A) anionic surfactant contains at least one selected from lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, and salts thereof. <4> The skin cleanser according to any one of <1> to <3>, wherein the (A) anionic surfactant contains at least one selected from the group consisting of polyoxyethylene (1) sodium lauryl ether sulfate, polyoxyethylene (1) lauryl ether ammonium sulfate, polyoxyethylene (1) sodium myristyl ether sulfate, polyoxyethylene (2) sodium lauryl ether sulfate, and polyoxyethylene (2) sodium myristyl ether sulfate. <5> The skin cleanser according to any one of <1> to <4>, wherein the (D) moisturizer contains at least one polyol that is liquid at 25°C selected from the group consisting of ethylene glycol, diethylene glycol, hexylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, isoprene glycol, 1,3-butylene glycol, 1,3-propanediol, glycerin, diglycerin, triglycerin, tetraglycerin, hexaglycerin, and decaglycerin trimethylpropanol. <6> The skin cleanser according to any one of <1> to <5>, wherein the amphoteric surfactant (E) contains at least one selected from alkylamidopropyl betaine and alkylhydroxysulfobetaine having an alkyl group having 8 to 14 carbon atoms. <7> The skin cleanser according to any one of <1> to <6>, wherein the content of the component (A) in the skin cleanser is 1 to 20% by mass, preferably 3 to 15% by mass, and more preferably 3 to 10% by mass.<8> The skin cleanser according to any one of <1> to <7>, wherein the content of component (B) in the skin cleanser is 0.05 to 0.7% by mass, preferably 0.1 to 0.5% by mass, and more preferably 0.1 to 0.3% by mass. <9> The skin cleanser according to any one of <1> to <8>, wherein the content of component (C) in the skin cleanser is 50 to 80% by mass, preferably 60 to 80% by mass, and more preferably 70 to 80% by mass. <10> The skin cleanser according to any one of <1> to <9>, wherein the content of component (D) in the skin cleanser is 10 to 40% by mass, preferably 15 to 30% by mass, and more preferably 20 to 30% by mass. <11> The skin cleanser according to any one of <1> to <10>, having a viscosity at 30°C of 10 to 4000 mPa·s, preferably 20 to 2000 mPa·s, and more preferably 100 to 1000 mPa·s. <12> The skin cleanser according to any one of <1> to <11>, having a pH in the range of 5 to 11, and preferably in the range of 6 to 10. <13> The skin cleanser according to any one of <1> to <12>, wherein the component (B) has a v2 / v1 ratio of 700 or more, preferably 800 or more, and more preferably 900 or more. <14> The skin cleanser according to any one of <1> to <13>, wherein the mass ratio (A) / (B) of the component (A) to the component (B) is 5 to 100, preferably 7 to 50, and more preferably 10 to 20. <15> The skin cleanser according to any one of <3> to <14>, wherein the anionic surfactant (A) contains both a fatty acid salt and an alkyl ether carboxylate. <16> The skin cleanser according to any one of <1> to <15>, wherein the non-aerosol foamer container is a pump foamer container that discharges the skin by pressing a pump head.

[0066] Next, examples of the present invention will be described, but the present invention is not limited to these examples.

[0067] A 1% by mass aqueous solution of each of the polysaccharides shown in Table 1 was prepared, and the solution was stirred at a shear rate of 1.0 × 10 ３ (s －１ ) viscosity v1 at shear rate 1.0 × 10－１ (s －１ The viscosity v2 at a shear rate of 1.0 × 10 was measured, and the ratio (v2 / v1) was calculated. The acrylate copolymer was neutralized with potassium hydroxide to a pH of 7 to thicken the mixture, and then the viscosity v2 was measured at a shear rate of 1.0 × 10 ３ (s －１ ) viscosity v1 at shear rate 1.0 × 10 －１ (s －１ The viscosity v2 at each temperature was measured, and the ratio (v2 / v1) was calculated. The results are shown in Table 1.

[0068]

[0069] The ingredients used in preparing the skin cleanser are listed in Table 2 below, along with their label names and raw material names.

[0070]

[0071] Skin cleansers of Examples and Comparative Examples were produced with the compositions shown in Tables 3 to 9 below. For production, each component was added to water and dissolved by mixing and stirring. The viscosity and pH of the skin cleansers before filling were measured. Furthermore, each skin cleanser was filled into a discharge container X-2080 (Yoshino Kogyosho Co., Ltd.), which has the gas-liquid mixing mechanism described in the Examples of Japanese Patent No. 7193999, and discharged to examine foam performance and dischargeability. Specifically, the foam elasticity during discharge, foam appearance during discharge, ease of pumping, possibility of clogging, and foam thickness during washing were evaluated. The results obtained are also shown in Tables 3 to 9.

[0072] (Evaluation Methods) (1) Viscosity: The viscosity of each skin cleanser was measured at 30°C for 1 minute using a Brookfield viscometer (TVB-10 viscometer, manufactured by Toki Sangyo Co., Ltd.). Viscosities of less than 100 mPa·s were measured with rotor No. 1 (rotational speed) at 60 rpm, viscosities of 100 to 199 mPa·s were measured with rotor No. 1 (rotational speed) at 30 rpm, viscosities of 200 to 499 mPa·s were measured with rotor No. 1 (rotational speed) at 12 rpm, viscosities of 500 to 2499 mPa·s were measured with rotor No. 2 (rotational speed) at 12 rpm, and viscosities of 2500 mPa·s or higher were measured with rotor No. 3 (rotational speed) at 12 rpm.

[0073] (2) pH: The pH of each undiluted skin cleanser solution was measured at 30° C. using a pH electrode (manufactured by Horiba Ltd., Model: F-72).

[0074] (3) Foam Elasticity at the Time of Discharge: Three expert panelists discharged foam from the nozzle of the container onto the palm of one hand wetted with water (liquid volume: 2 mL), and immediately thereafter pressed their other hand against the discharged foam, and evaluated the degree of foam elasticity felt by the other hand according to the following criteria. The evaluations were determined by discussion based on the evaluations of the three expert panelists. 5: Very elastic. 4: Elastic. 3: Somewhat elastic. 2: Somewhat lacking elasticity. 1: No elasticity. Foam elasticity is considered acceptable if it is rated 3 or higher.

[0075] (4) Foam appearance upon dispensing: Three expert panelists pressed the pump with their palms to dispense foam, visually inspected its appearance, and evaluated it according to the following criteria. The evaluation was determined through discussion based on the evaluations of the three expert panelists. 5: The bubbles are all of the same size and are fine. 4: The bubbles are all of the same size, but there are coarse bubbles (diameter of approximately 3 mm or less). 3: The bubbles are all of the same size, but there are some slightly larger bubbles (diameter less than approximately 5 mm). 2: The bubbles are all of different sizes, with slightly larger bubbles (diameter less than approximately 5 mm) accounting for more than half of the surface. 1: The bubbles are all of different sizes, with large bubbles (diameter of approximately 5 mm or more) accounting for more than half of the surface. A rating of 3 or higher for foam appearance is acceptable.

[0076] (5) Ease of pressing the pump: Three expert panelists evaluated the ease of pressing the pump when they pressed it with their palm to expel foam from the nozzle, according to the following criteria. The ratings were determined through discussion based on the evaluations of the three expert panelists. 5: Very easy to press. 4: Easy to press. 3: Somewhat easy to press. 2: Somewhat heavy and difficult to press. 1: Very heavy and difficult to press. A rating of 3 or higher for the ease of pressing of the pump is acceptable.

[0077] (6) Possibility of clogging: 2 mL of the undiluted solution of the skin cleanser was dropped into a 5 cm diameter Petri dish, and left to stand uncovered in an environment of 30°C and 20% relative humidity, and the state of the liquid after 24 hours was evaluated. A: The entire liquid was transparent (no crystals precipitated), and when cigarette paper (RIZLA BLUE DOUBLE) was pressed against the sample surface, the fluid liquid adhered to the cigarette paper. B: Crystals precipitated in part of the liquid, but when the cigarette paper was pressed against the sample surface, the fluid liquid adhered to the cigarette paper. C: Crystals precipitated throughout the liquid, and when the cigarette paper was pressed against the sample surface, the fluid liquid did not adhere to the cigarette paper. The possibility of clogging was passed if it was A or B.

[0078] (7) Thickness of foam during washing: Three expert panelists dispensed foam from the nozzle of the container onto the palm of one hand wetted with water (liquid volume: 2 mL), then immediately placed their other hand over the dispensed foam and rubbed their hands together 20 times, after which the degree of foam thickness (volume) was evaluated according to the following criteria. The evaluation was determined by discussion based on the evaluations of the three expert panelists. 5: Very thick. 4: Thick. 3: Somewhat thick. 2: Somewhat thin. 1: Thin. A foam thickness of 3 or higher was considered acceptable.

[0079] The skin cleanser of the present invention is required to have a viscosity and pH within a predetermined range and to pass all evaluation items. All values ​​shown in the table are values ​​for the active ingredients.

[0080]

[0081]

[0082]

[0083]

[0084]

[0085]

[0086]

[0087] The skin cleanser of the example passed all evaluations of foam elasticity when dispensed, foam appearance when dispensed, ease of pressing the pump, possibility of clogging, and foam thickness when cleansing, confirming that it combines excellent foam performance with good dispenseability.

Claims

1. The following components (A), (B), and (C): (A) 1 to 20 mass% anionic surfactant; (B) a 1 mass% aqueous solution with a viscosity of 1.0 x 10 at a shear rate of 1.0 x 10 ３ (s －１ ) and viscosity v1 at a shear rate of 1.0 × 10 －１ (s －１ (C) 0.05 to 0.7 mass % of a polysaccharide having a viscosity v1 / v2 ratio (v2 / v1) of 700 or more, and (D) 80 mass % or less of water, and the skin cleanser is used by being discharged in the form of foam from a non-aerosol foamer container.

2. The skin cleanser according to claim 1, wherein the anionic surfactant (A) contains at least one selected from fatty acid salts, alkyl ether carboxylates, N-acylamino acid salts, alkyl ether sulfates, and sulfonates.

3. A skin cleanser according to claim 1 or 2, wherein the polysaccharide (B) contains at least one selected from the group consisting of xanthan gum, cationized xanthan gum, diutan gum, and welan gum.

4. The skin cleanser according to claim 3, wherein the mass ratio (A) / (B) of said component (A) to said component (B) is 5 to 100.

5. A skin cleanser according to claim 1 or 2, further comprising 10 to 40% by mass of a moisturizing agent (D).

6. A skin cleanser according to claim 5, wherein the moisturizing agent (D) is a polyol that is liquid at 25°C.

7. A skin cleanser according to claim 1 or 2, further comprising (E) an amphoteric surfactant.

8. A skin cleanser according to claim 7, wherein the amphoteric surfactant (E) contains at least one selected from sulfobetaine type, aminoacetic acid betaine type, glycine type, and amine oxide type.

9. The skin cleanser according to claim 1 or 2, which has a viscosity at 30°C of 10 to 4000 mPa·s.

10. A non-aerosol foamer container and the following components (A), (B), and (C): (A) 1 to 20 mass% anionic surfactant; (B) a 1 mass% aqueous solution with a viscosity of 1.0 x 10 at a shear rate of 1.0 x 10 ３ (s －１ ) and viscosity v1 at a shear rate of 1.0 × 10 －１ (s －１ and (C) 0.05 to 0.7 mass % of a polysaccharide having a viscosity v1 / v2 ratio (v2 / v1) of 700 or more, and (D) 80 mass % or less of water, wherein the skin cleanser is used by being discharged in the form of foam from the non-aerosol foamer container.

11. A foaming surfactant 1 to 20% by mass and a polysaccharide, the viscosity of which in a 1% by mass aqueous solution is such that the shear rate is 1.0 x 10 ３ (s －１ ) Shear rate 1.0 × 10 －１ (s －１ 0.05 to 0.7% by mass of a polysaccharide having a viscosity v1 / v2 ratio (v2 / v1) of 700 or more at a temperature of 1000°C, and 80% by mass or less of water, and discharging the liquid composition in the form of foam from a non-aerosol foamer container containing the liquid composition.

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