Hair cleansing agent

Abstract

To provide a hair cleansing agent that exhibits mild properties, superior preservation stability under low-temperature conditions, and can be adjusted to an appropriate viscosity as a liquid cleansing agent.SOLUTION: A hair cleansing agent comprises the following components (A)-(C): (A) at least one selected from the group consisting of polyoxyalkylene alkyl ether acetates having an average number of added moles of oxyalkylene groups of more than 0 and 4 or less, and salts thereof; (B) at least one selected from the group consisting of N-acyl amino acids and salts thereof; and (C) fatty acid N-monoethanolamide, wherein the content of the component (A) in the hair cleansing agent is 3.0 mass% or more and 11 mass% or less, and the content of (B1) N-acylalanine and salts thereof in the component (B) is 20 mass% or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a hair cleanser. [Background technology]

[0002] In recent years, amino acid-based surfactants, which have mild properties that cause little irritation to the scalp and skin, have become popular on the market as cleansing components for hair washes. However, amino acid-based surfactants sometimes do not have sufficient cleansing properties, and the present inventors have focused on polyoxyalkylene alkyl ether acetic acid, which has good cleansing properties in addition to mildness.

[0003] As an example of a technology using polyoxyalkylene alkyl ether acetic acid, Patent Document 1 discloses a skin cleanser that combines polyoxyethylene alkyl ether carboxylic acid and a higher fatty acid with a specific surfactant and a water-soluble polymer, and that has high storage stability at low and high temperatures and excellent spreadability when applied to the hands. Patent Document 2 discloses a liquid cleanser that contains an N-acyl acidic amino acid, a specific alkyl ether carboxylic acid, a specific amphoteric surfactant, and water, and that has improved storage stability at low temperatures, is thick yet spreads easily on the skin, has long-lasting foaming properties, is easy to rinse off, and leaves the skin feeling smooth and protected after washing, with reduced irritation to the skin caused by cleansing. Patent Document 3 discloses a cleanser composition that contains a combination of a specific ether carboxylic acid surfactant and a specific glyceryl ether, which is mild to the skin, foams well, leaves skin feeling moisturized after rinsing, and has excellent low-temperature stability. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-79743 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-117967 [Patent Document 3] Japanese Patent Application Laid-Open No. 2001-115187 Summary of the Invention [Problem to be solved by the invention]

[0005] The skin cleanser in Patent Document 1 aims to maintain storage stability at low temperatures by increasing viscosity, but when used as a hair cleanser, it is not suitable because of its poor foaming properties when the viscosity is high. In addition, the higher fatty acids may cause hair to squeak, and the hair may not be easy to run your fingers through after washing.

[0006] Patent Document 2 attempts to suppress the precipitation of N-acyl amino acids at low temperatures by blending specific alkyl ether carboxylic acids with N-acyl amino acids. However, liquid detergents using N-acyl acid amino acids tend to lose viscosity, making them difficult to handle when used in containers other than foamer containers, such as when the liquid detergent is dispensed onto the hands, causing dripping.

[0007] Patent Document 3 uses a specific ether carboxylic acid surfactant, and discloses an improvement in storage stability even though the average number of moles added is relatively high, but does not disclose the storage stability at low temperatures of ether carboxylic acid surfactants with a low average number of moles added.

[0008] Incidentally, it is known that the foaming properties of polyoxyalkylene alkyl ether acetic acids vary depending on the average number of moles of oxyalkylene groups added. To obtain a hair wash agent that foams well, it is preferable to select a polyoxyalkylene alkyl ether acetic acid having an average number of moles of oxyalkylene groups added of 4 or less. On the other hand, if the average number of moles of polyoxyalkylene alkyl ether added is low, storage stability in low-temperature environments tends to decrease, and further, when made into a liquid detergent, the viscosity becomes too low, so improvement in its handleability is also required. The present invention relates to a hair cleanser that has mildness and sufficient cleansing properties, has excellent storage stability in low-temperature environments, and can be adjusted to a suitable viscosity for easy handling as a liquid cleanser. [Means for solving the problem]

[0009] The present inventors have found that a hair wash agent containing a polyoxyalkylene alkyl ether acetic acid having a low average number of added moles in combination with a specific amino acid-derived surfactant and a fatty acid N-methylethanolamide can solve the above-mentioned problems. That is, the present invention provides: The following components (A) to (C): (A) one or more selected from the group consisting of polyoxyalkylene alkyl ether acetic acids and salts thereof, in which the average number of moles of oxyalkylene groups added is more than 0 and not more than 4; (B) one or more selected from the group consisting of N-acylamino acids and salts thereof, and (C) fatty acid N-methylethanolamide, A hair cleanser comprising: The content of the component (A) in the hair wash is 3.0% by mass or more and 11% by mass or less, The present invention relates to a hair wash agent in which the content of (B1) N-acylalanine and salts thereof in the component (B) is 20 mass % or more. [Effects of the Invention]

[0010] The hair cleanser of the present invention has mildness and sufficient cleansing properties, excellent storage stability in low-temperature environments, and can be adjusted to a suitable viscosity that makes it easy to handle as a liquid cleanser. DETAILED DESCRIPTION OF THE INVENTION

[0011] [Hair cleanser] The hair cleansing agent of the present invention comprises: (A) one or more selected from the group consisting of polyoxyalkylene alkyl ether acetic acids and salts thereof, in which the average number of moles of oxyalkylene groups added is more than 0 and not more than 4; (B) one or more members selected from the group consisting of N-acylamino acids and salts thereof, and (C) fatty acid N-methylethanolamide, A hair cleanser comprising: The content of the component (A) in the hair wash is 3.0% by mass or more and 11% by mass or less, In the hair wash, the content of (B1) N-acylalanine and salts thereof in the component (B) is 20% by mass or more. By virtue of the above-described constitution, the hair cleanser of the present invention is a hair cleanser that has mildness and sufficient cleansing properties, has excellent storage stability in low-temperature environments, and can be adjusted to an appropriate viscosity that is easy to handle.

[0012] <Definition> In the present invention, "hair" primarily refers to human head hair, but also includes hair that has been cut off from the human head. In the present invention, "comprises component X" or "contains component X" also means "composed of component X." In the present invention, storage stability at -5°C is used as an index of "storage stability in a low-temperature environment." If the storage stability at -5°C is excellent, the hair cleanser can be suitably used even in usage environments in cold regions. Hereinafter, "storage stability in a low-temperature environment" will also be simply referred to as "low-temperature stability."

[0013] The reason why the hair cleansing agent of the present invention having the above-described structure exhibits the effects of the present invention is not clear, but is presumed to be as follows. The hair wash composition of the present invention contains, as component (A), one or more polyoxyalkylene alkyl ether acetic acids and salts thereof, each having an average number of moles of oxyalkylene groups added that is greater than 0 and not greater than 4; as component (B), one or more N-acylamino acids and salts thereof, and as component (C), a fatty acid N-methylethanolamide. The hair cleanser can be imparted with cleansing properties by containing component (A). More specifically, when washing hair with the hair cleanser, dirt such as sebum is trapped in the micelles formed by component (A), an anionic surfactant, and the dirt trapped in the micelles is washed away during rinsing. On the other hand, when component (A) is exposed to a low-temperature environment below the Krafft point, the packing between the surfactants becomes dense, hydrate crystals are precipitated, and stability (transparency) is thought to decrease. However, in the present invention, by blending component (B), an amino acid surfactant with a bulky hydrophilic group, components (A) and (B) form mixed micelles even in a low-temperature environment, which is thought to lower the Krafft point and improve low-temperature stability. Furthermore, it is difficult to thicken a hair cleanser using only component (A) and component (B). However, by incorporating component (C), the formation and growth of mixed micelles is promoted, thereby thickening the hair cleanser and enabling viscosity adjustment, while maintaining the improved low-temperature stability described above.

[0014] <Component (A): Polyoxyalkylene alkyl ether acetic acid and salts thereof having an average number of moles of oxyalkylene groups added that is more than 0 and not more than 4> The hair wash agent of the present invention contains, as component (A), one or more selected from the group consisting of polyoxyalkylene alkyl ether acetic acids and salts thereof, each having an average number of moles of oxyalkylene groups added that is greater than 0 and not greater than 4. Component (A) is a carboxylic acid surfactant, and the inclusion of component (A) in the hair wash agent can impart cleansing properties.

[0015] From the viewpoints of mildness, detergency, low-temperature stability, viscosity adjustment, blend stability, and ease of availability, component (A) used in the present invention comprises one or more polyoxyalkylene alkyl ether acetic acids and salts thereof, each having an average number of moles of oxyalkylene groups added of more than 0 and not more than 4. Here, examples of polyoxyalkylene alkyl ether acetic acids and salts thereof include compounds represented by the following general formula (I). R 1 -O-(R2 O) n -CH2-COOM (I) (In formula (I), R 1 represents a linear or branched alkyl group having 8 to 22 carbon atoms, R 2 represents an alkylene group having 2 or 3 carbon atoms, M represents a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium, an alkanolamine or a basic amino acid, and n is the average number of moles added and is a number greater than 0 and equal to or less than 4.

[0016] In formula (1), R 1 is preferably a linear or branched alkyl group having from 10 to 18 carbon atoms, more preferably a linear or branched alkyl group having from 12 to 16 carbon atoms, and even more preferably a linear alkyl group having from 12 to 16 carbon atoms. Also, n is preferably from 1 to 3. In formula (1), R 2 is preferably an ethylene group having 2 carbon atoms. In formula (1), M is preferably a hydrogen atom, an alkali metal or ammonium, more preferably an alkali metal, even more preferably sodium or potassium, and still more preferably sodium.

[0017] Specific examples of the polyoxyalkylene alkyl ether carboxylic acid and its salt include polyoxyethylene lauryl ether acetic acid (laureth acetic acid) and polyoxyethylene lauryl ether sodium acetate (sodium laureth acetate), each of which has an average number of moles of oxyalkylene groups added of more than 0 and 4 or less. Commercially available laureth acetate products include "Kao Akipo LM-26C" (average number of moles added, n = 2.6) manufactured by Kao Corporation. Commercially available sodium laureth acetate products include "Kao Akipo LM-26SD" (average number of moles added, n = 2.6) manufactured by Kao Corporation and the "Viewlite LCA" series (average number of moles added, n = 2 to 4) manufactured by Sanyo Chemical Industries, Ltd. The component (A) can be used alone or in combination of two or more.

[0018] <Component (B): N-acylamino acids and their salts> The hair cleanser of the present invention contains one or more N-acylamino acids and their salts as component (B). By including component (B) in the hair cleanser, the low-temperature stability of the hair cleanser can be improved. The component (B) used in the present invention contains one or more selected from the group consisting of N-acylamino acids and their salts from the viewpoints of mildness, low-temperature stability, viscosity adjustment, blend stability, and easy availability. In this specification, N-acylamino acids refer to amino acid surfactants in which the amino group of amino acids and related compounds is acylated, and also include compounds in which the hydrogen atom of the amino group is substituted with a methyl group. Here, examples of amino acid related compounds include taurine and the like and their derivatives.

[0019] Examples of amino acids that form amino acid-derived structures in N-acylamino acids and salts thereof include neutral amino acids such as glycine, alanine (including both α-alanine and β-alanine), methylalanine, valine, leucine, isoleucine, cysteine, proline, serine, threonine, and sarcosine (N-methylglycine); acidic amino acids such as glutamic acid and aspartic acid; and, as mentioned above, taurine and its derivative, methyltaurine. Among these, from the viewpoints of low-temperature stability, viscosity adjustment, and blending stability, methylalanine, glutamic acid, aspartic acid, methyltaurine, and sarcosine are preferred, and methylalanine is more preferred. When these amino acids have optical isomers, they may be either the D-form, the L-form, or a mixture of the D- and L-forms, but the L-form is preferred.

[0020] From the viewpoints of mildness, low-temperature stability, viscosity adjustment, and blend stability, the acyl group in the N-acylamino acid and salts thereof is preferably a saturated or unsaturated, straight-chain or branched-chain acyl group having from 8 to 22 carbon atoms. Examples of the acyl group include caproyl, capryloyl, caprinoyl, lauroyl, myristoyl, palmitoyl, stearoyl, isostearoyl, oleoyl, linoleoyl, cocoyl (coconut oil fatty acid acyl group), palm oil fatty acid acyl group, palm kernel oil fatty acid acyl group, beef tallow fatty acid acyl group, and straight-chain or branched chain synthetic fatty acid acyl groups. Of these, the number of carbon atoms in the acyl group is more preferably 10 or more, even more preferably 12 or more, from the viewpoints of mildness, low-temperature stability, viscosity adjustment, and blend stability, and is more preferably 20 or less, even more preferably 18 or less, and still more preferably 16 or less. Specifically, the acyl group is preferably one or more selected from the group consisting of a lauroyl group, a myristoyl group, a palmitoyl group, a stearoyl group, and a cocoyl group, and more preferably one or more selected from the group consisting of a lauroyl group and a cocoyl group.

[0021] Here, as the N-acylamino acid and its salt, from the viewpoints of mildness, low-temperature stability, viscosity adjustment, blending stability, and easy availability, the component (B) contains component (B1) N-acylalanine and its salt. Preferred types of these salts include sodium salt, potassium salt, arginine salt, and triethanolamine salt. The N-acylalanine includes compounds in which the amino group of alanine is acylated, including compounds in which the hydrogen atom bonded to the acylated amino group is substituted with a methyl group or a hydroxyethyl group. As mentioned above, the alanine used here includes not only α-alanine but also β-alanine. Specific examples of this component (B1) include N-lauroylmethylalanine, N-myristoylmethylalanine, N-cocoylmethylalanine, N-lauroylhydroxyethyl-β-alanine, and salts thereof, with sodium N-lauroylmethylalanine being preferred.

[0022] (B1) As N-acylalanine and its salts, commercially available amino acid surfactants can also be used. Examples of commercially available N-acylalanine and its salts include "Alanon ACE" (coconut oil fatty acid methylalanine sodium), "Alanon ALE" (lauroylmethyl-β-alanine sodium), "Alanon ALTA" (N-lauroyl-N-methyl-β-alanine triethanolamine), "Alanon AME" (myristoylmethyl-β-alanine sodium), and "Luminovail HS-L" (lauroylhydroxyethyl-β-alanine sodium), all manufactured by Kawaken Fine Chemical Co., Ltd. The component (B1) can be used alone or in combination of two or more.

[0023] In addition, the N-acylamino acid and its salt used other than component (B1) is preferably one or more selected from the group consisting of N-acylglutamic acid, N-acylaspartic acid, N-acylmethyltaurine and their salts, from the viewpoints of mildness, low-temperature stability, viscosity adjustment, blending stability, and easy availability. In addition, the types of these salts preferably include sodium salts, potassium salts, arginine salts, and triethanolamine salts.

[0024] Specific examples of N-acylamino acids and their salts other than component (B1) include N-capryloyl glutamic acid, N-2-ethylhexanoyl glutamic acid, N-lauroyl glutamic acid, N-myristoyl glutamic acid, N-palmitoyl glutamic acid, N-stearoyl glutamic acid, N-cocoyl glutamic acid, N-palm oil fatty acid acyl glutamic acid, N-tallow fatty acid acyl glutamic acid, N-lauroyl aspartic acid, N-myristoyl aspartic acid, N-palmitoyl aspartic acid, N-stearoyl aspartic acid, N-cocoyl aspartic acid, N-lauroyl methyl taurine, N-myristoyl methyl taurine, N-cocoyl methyl taurine and their salts.The types of these salts include, for example, sodium salt, potassium salt, arginine salt, and triethanolamine salt.

[0025] As the N-acylamino acid and its salt other than component (B1), commercially available amino acid surfactants can also be used. Commercially available N-acylamino acid and its salt other than component (B1) include, for example, "Amisoft CS-22BE" (N-coconut oil fatty acid acyl-L-glutamic acid monosodium salt), "Amisoft LS-11" (N-lauroyl-L-glutamic acid monosodium salt), "Amisoft CS-11(F)" (N-cocoyl-L-glutamic acid monosodium salt), "Amisoft MS-11" (N-myristoyl-L-glutamic acid monosodium salt), "Amisoft MK-11" and "Amisoft MK-11(F)" (N-myristoyl-L-glutamic acid potassium salt), "Amisoft GS-11P" (mixture of N-stearoyl-L-glutamic acid monosodium salt and N-cocoyl-L-glutamic acid monosodium salt), and "Amisoft" manufactured by Ajinomoto Co., Inc. HS-11P" (N-stearoyl-L-glutamic acid sodium); "Aminoformer FCMT-L" (mixed fatty acid (C12,14) acyl-L-aspartic acid triethanolamine) manufactured by Asahi Kasei Finechem Co., Ltd.; "Diapon K-SF" (cocoyl methyl taurate sodium), "Diapon K-SG" (cocoyl methyl taurate sodium), "Diapon HF-SF" (caproyl methyl taurate sodium) manufactured by NOF Corporation. The component (B) other than the component (B1) can be used alone or in combination of two or more.

[0026] In the hair wash agent of the present invention, component (B) contains component (B1), and the content of component (B1) in component (B) is 20% by mass or more from the viewpoints of mildness, low-temperature stability, viscosity adjustment, and blending stability. The content of component (B1) in component (B) is preferably 25% by mass or more, more preferably 30% by mass or more, even more preferably 40% by mass or more, even more preferably 50% by mass or more, even more preferably 60% by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, and preferably 100% by mass or less. The content of component (B1) in component (B) may be 100% by mass.

[0027] <Component (C): Fatty acid N-methylethanolamide> The hair cleanser of the present invention contains a fatty acid N-methylethanolamide as component (C). Component (C) maintains the low-temperature stability achieved by the blending of components (A) and (B) above, while enabling the liquid hair cleanser to have an appropriate viscosity. In addition, when combined with components (A) and (B), component (C) strengthens the foam film, contributing to improved foaming power and foam persistence during cleansing.

[0028] This fatty acid N-methylethanolamide is a nonionic surfactant obtained by a condensation reaction between a fatty acid and N-methylethanolamine. From the viewpoints of mildness, low-temperature stability, viscosity adjustment, blend stability, and easy availability, the fatty acid N-methylethanolamide preferably has an acyl group having from 8 to 22 carbon atoms, more preferably from 8 to 20 carbon atoms, and even more preferably from 8 to 18 carbon atoms.

[0029] Specific examples of fatty acid N-methylethanolamides include coconut oil fatty acid N-methylethanolamide. Commercially available fatty acid N-methylethanolamides include "Aminone C-11S" (coconut oil fatty acid N-methylethanolamide) manufactured by Kao Corporation. The component (C) can be used alone or in combination of two or more.

[0030] <Component (D): Amphoteric surfactant> The hair cleansing agent of the present invention may further contain an amphoteric surfactant as component (D) for the purpose of adding cleansing properties and conditioning effects. This component (D) is an optional component. Examples of the amphoteric surfactant (D) used herein include betaine surfactants and amine oxide surfactants. Among these, betaine surfactants are preferred from the viewpoints of mildness, low-temperature stability, viscosity adjustment, blend stability, and easy availability. One or more amphoteric surfactants can be used.

[0031] Examples of betaine surfactants include carboxybetaine surfactants such as alkyldimethylaminoacetic acid betaine and fatty acid amidopropyl betaine; sulfobetaine surfactants such as alkylsulfobetaine and alkylhydroxysulfobetaine; imidazoline betaine surfactants; and phosphobetaine surfactants.

[0032] The alkyldimethylaminoacetic acid betaine preferably has an alkyl group having from 8 to 22 carbon atoms, more preferably from 10 to 20 carbon atoms, and specific examples include lauryldimethylaminoacetic acid betaine and stearyldimethylaminoacetic acid betaine. The fatty acid amidopropyl betaine preferably includes those having an acyl group having from 8 to 18 carbon atoms, more preferably from 10 to 16 carbon atoms. Specific examples include lauric acid amidopropyl betaine (lauramidopropyl betaine), palm kernel oil fatty acid amidopropyl betaine, and coconut oil fatty acid amidopropyl betaine (cocamidopropyl betaine).

[0033] The alkyl sulfobetaine preferably includes an alkyl sulfobetaine having an alkyl group having from 8 to 22 carbon atoms, more preferably from 10 to 18 carbon atoms. Specific examples of alkyl sulfobetaine include lauryl dimethyl sulfoethyl betaine, lauryl dimethyl sulfopropyl betaine, myristyl dimethyl sulfoethyl betaine, myristyl dimethyl sulfopropyl betaine, stearyl dimethyl sulfoethyl betaine, stearyl dimethyl sulfopropyl betaine, and coconut oil fatty acid dimethyl sulfopropyl betaine.

[0034] The alkylhydroxysulfobetaine preferably includes an alkyl group having from 8 to 22 carbon atoms, more preferably from 10 to 18 carbon atoms, and at least one hydroxy group. Specific examples of alkylhydroxysulfobetaine include lauryl dimethyl sulfo(hydroxyethyl)betaine, lauryl dimethyl sulfo(hydroxypropyl)betaine (also known as lauryl hydroxysultaine or lauryl hydroxysulfobetaine), myristyl dimethyl sulfo(hydroxyethyl)betaine, myristyl dimethyl sulfo(hydroxypropyl)betaine, stearyl dimethyl sulfo(hydroxypropyl)betaine, bis-(2-hydroxyethyl)sulfoethyl betaine, and lauryl bis-(2-hydroxyethyl)sulfopropyl betaine.

[0035] Examples of imidazoline betaine amphoteric surfactants include N-acylaminoethyl-N-2-hydroxyethylaminocarboxylates, such as N-cocoacyl-N'-carboxymethyl-N'-hydroxyethylethylenediamine (also known as sodium cocoamphoacetate or 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine), N-cocoacyl-N'-carboxyethyl-N'-hydroxyethylethylenediamine (sodium cocoamphopropionate), and N-lauroyl-N'-carboxymethyl-N'-hydroxyethylethylenediamine sodium (sodium lauroamphoacetate). An example of the phosphobetaine type amphoteric surfactant is lauryl hydroxyphosphobetaine.

[0036] Among the above, from the viewpoints of mildness, low-temperature stability, viscosity adjustment, formulation stability, and easy availability, the amphoteric surfactant is more preferably one or more selected from the group consisting of carboxybetaine type or sulfobetaine type, even more preferably one or more selected from the group consisting of fatty acid amidopropyl betaine and alkylhydroxysulfobetaine, and even more preferably one or more selected from the group consisting of lauric acid amidopropyl betaine and lauryl dimethyl sulfo(hydroxypropyl)betaine.

[0037] <Aqueous medium> Hair washes typically contain an aqueous medium. Examples of the aqueous medium include water and water-soluble organic solvents. Examples of the water-soluble organic solvent include lower alcohols such as ethanol and isopropyl alcohol; and low-molecular-weight diols or triols having 6 or less carbon atoms, such as 1,3-butylene glycol, glycerin, ethylene glycol, propylene glycol, and dipropylene glycol. Among these, it is preferable to use water as the aqueous medium.

[0038] <Other ingredients> The hair cleanser of the present invention may contain other components besides components (A) to (D) as appropriate, provided that the purpose of the present invention is not impaired. Examples of such components include surfactants other than components (A) to (D), and components typically incorporated into hair cleansers, such as antioxidants, oils, polymers, antidandruff agents, vitamins, bactericides, anti-inflammatory agents, preservatives, chelating agents, moisturizers, ceramides, fragrances, colorants, UV absorbers, and pH adjusters.

[0039] As anionic surfactants other than component (A), one or more selected from the group consisting of (A') polyoxyalkylene alkyl ether acetic acids and salts thereof, each having an average number of moles of oxyalkylene groups added of more than 4, may be used. This (A') polyoxyalkylene alkyl ether acetic acid and its salt, in which the average number of moles of oxyalkylene groups added exceeds 4, is a compound having a similar structure to the compound represented by general formula (I) described above for component (A), except that the average number of moles added, n, exceeds 4.

[0040] Specific examples of the polyoxyalkylene alkyl ether carboxylic acid and its salt include polyoxyethylene lauryl ether acetic acid (laureth acetic acid) and polyoxyethylene lauryl ether sodium acetate (sodium laureth acetate), which have an average number of moles of oxyalkylene groups added of more than 4. Commercially available products of sodium laureth acetate include "Kao Akipo RLM-45NV" (average number of moles added, n=4.5) and "Kao Akipo RLM-100NV" (average number of moles added, n=10) manufactured by Kao Corporation.

[0041] Examples of anionic surfactants other than component (A) and component (B) include sulfate-type anionic surfactants such as alkyl sulfates, alkenyl sulfates, polyoxyalkylene alkyl ether sulfates, polyoxyalkylene alkenyl ether sulfates, and alkylene alkyl phenyl ether sulfosuccinate sulfates; and sulfonic acid-type anionic surfactants such as alkyl sulfosuccinate ester salts, polyoxyalkylene alkyl sulfosuccinate ester salts, alkanesulfonates, and alkenesulfonates. Of these, sulfonic acid-type anionic surfactants are preferred, and alkenesulfonates are more preferred, with sodium olefin (C14-16)sulfonate being a specific example.

[0042] <Content> In terms of mildness, low-temperature stability, viscosity adjustment, and blending stability, the hair cleansing agent of the present invention preferably contains each component in the following ranges.

[0043] The content of component (A) in the hair wash is 3.0% by mass or more and 11% by mass or less from the viewpoints of mildness, low-temperature stability, viscosity adjustment, and blend stability. From the same viewpoints as above, the content of component (A) is preferably 4.0% by mass or more, more preferably 4.5% by mass or more, even more preferably 5.0% by mass or more, still more preferably 5.5% by mass or more, and preferably 10% by mass or less, more preferably 9.0% by mass or less, even more preferably 8.0% by mass or less, and still more preferably 7.0% by mass or less.

[0044] From the viewpoint of cleansing properties, the content of component (A') in the hair wash is, for example, 5.0 mass % or less, preferably 3.0 mass % or less, more preferably 1.0 mass % or less, and even more preferably 0 mass %.

[0045] From the viewpoints of mildness, low-temperature stability, viscosity adjustment, and blending stability, the content of component (B) in the hair wash is preferably 2.0% by mass or more, more preferably 3.0% by mass or more, even more preferably 4.0% by mass or more, still more preferably 4.5% by mass or more, and is preferably 18% by mass or less, more preferably 14% by mass or less, even more preferably 10% by mass or less, and still more preferably 8.0% by mass or less.

[0046] From the viewpoints of mildness, low-temperature stability, viscosity adjustment, and blending stability, the content of component (B1) in the hair wash is preferably 1.0% by mass or more, more preferably 1.5% by mass or more, even more preferably 1.8% by mass or more, still more preferably 2.2% by mass or more, still more preferably 3.0% by mass or more, and is preferably 18% by mass or less, more preferably 10% by mass or less, even more preferably 10% by mass or less, still more preferably 8.0% by mass or less, and still more preferably 6.0% by mass or less.

[0047] The content of the anionic surfactant other than components (A) and (B) is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 3% by mass or more, based on the total amount of the hair wash, from the viewpoint of further improving foaming without impairing the object of the present invention. Also, from the viewpoint of improving foam rinse-off and suppressing residual feeling after rinsing, the content of the anionic surfactant other than components (A) and (B) is preferably 20% by mass or less, more preferably 17% by mass or less, and even more preferably 15% by mass or less, based on the total amount of the hair wash.

[0048] From the viewpoints of mildness, low-temperature stability, viscosity adjustment, and blending stability, the content of component (C) in the hair wash is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, even more preferably 1.5% by mass or more, still more preferably 2.0% by mass or more, and is preferably 8.0% by mass or less, more preferably 6.0% by mass or less, even more preferably 5.0% by mass or less, and still more preferably 4.0% by mass or less.

[0049] From the viewpoints of mildness, low-temperature stability, viscosity adjustment, and blending stability, the content of component (D) in the hair wash is preferably 0% by mass or more, more preferably 0.5% by mass or more, even more preferably 1.0% by mass or more, still more preferably 1.5% by mass or more, and is preferably 8.0% by mass or less, more preferably 6.0% by mass or less, even more preferably 4.0% by mass or less, and still more preferably 3.0% by mass or less.

[0050] From the viewpoint of adjusting the concentration and viscosity of the hair wash to an appropriate level, the content of the aqueous medium in the hair wash is preferably 60% by mass or more, more preferably 65% ​​by mass or more, even more preferably 70% by mass or more, and is preferably 94% by mass or less, more preferably 92% by mass or less, even more preferably 90% by mass or less.

[0051] From the viewpoints of mildness, low-temperature stability, viscosity adjustment, and blending stability, the mass ratio of component (B) to component (A) in this hair wash [(B) / (A)] is preferably 0.6 or more, more preferably 0.8 or more, even more preferably 0.9 or more, still more preferably 0.95 or more, still more preferably 1.0 or more, and is preferably 5.0 or less, more preferably 4.0 or less, even more preferably 3.0 or less, still more preferably 2.0 or less, still more preferably 1.5 or less, and still more preferably 1.2 or less. From the viewpoints of mildness, low-temperature stability, viscosity adjustment, and blending stability, the mass ratio of component (B1) to component (A) in this hair wash [(B1) / (A)] is preferably 0.25 or more, more preferably 0.40 or more, even more preferably 0.50 or more, still more preferably 0.54 or more, and is preferably 4.0 or less, more preferably 2.0 or less, even more preferably 1.5 or less, and still more preferably 1.2 or less.

[0052] (Method for manufacturing hair cleanser) The method for producing the hair cleansing agent of the present invention is not particularly limited. For example, the hair cleansing agent can be produced by blending components (A) to (C), and optionally component (D) and other components, using a known method, such as the method described in the Examples, and mixing them using a known stirring device or the like.

[0053] The hair cleanser thus obtained may be in any form, such as liquid or foam, but is preferably in liquid form. When the hair wash agent of the present invention is in liquid form, for ease of handling, its viscosity at 30°C is preferably 700 mPa·s or more, more preferably 900 mPa·s or more, even more preferably 1100 mPa·s or more, and preferably 4000 mPa·s or less, more preferably 3500 mPa·s or less, even more preferably 3000 mPa·s or less. The viscosity of the hair wash at 30°C can be measured, for example, using a Brookfield viscometer, specifically by the method described in the Examples.

[0054] From the viewpoints of mildness, low-temperature stability, viscosity adjustment, and formulation stability, the pH of the hair wash of the present invention is preferably 4.5 or more, more preferably 5.0 or more, even more preferably 5.5 or more, and still more preferably 5.8 or more, and is preferably 7.0 or less, more preferably 6.5 or less, and even more preferably 6.3 or less. The pH of this hair wash simulates the pH at the time of application to hair and is the value at 25°C when diluted 20 times by mass with ion-exchanged water, and can be measured specifically by the method described in the Examples. The pH can be adjusted by adding a known pH adjuster to the desired pH. As the pH adjuster, an organic acid, particularly an α-hydroxy acid, is preferably used, and specific examples include malic acid, citric acid, lactic acid, glycolic acid, etc. These organic acids may be used alone or in combination of two or more. Furthermore, as another pH adjuster, a base such as sodium hydroxide, potassium hydroxide, or ammonium chloride may be used in combination with these organic acids. [Example]

[0055] The present invention will be described below with reference to examples, but the present invention is not limited to the scope of the examples.

[0056] [Examples 1 to 14, Comparative Examples 1 to 7] (Preparation and Evaluation of Hair Cleansing Agents) Components (A), (B), (C), and (D) were mixed according to the formulations shown in Tables 1 and 2, and then heated to 70 to 80°C to completely dissolve in water (purified water). If any unneutralized component (A) remained, it was neutralized by adding sodium hydroxide (caustic soda). Subsequently, a polymer and an oil were added as other ingredients and stirred until uniform. After cooling to room temperature, preservatives, fragrances, and pH adjusters (citric acid and sodium hydroxide (caustic soda)) were added to adjust the pH to 6.2, yielding a hair cleanser. The pH was measured using an aqueous dispersion prepared by diluting the hair cleanser to 5% (20 times by mass) with purified water, and measuring the pH at 25°C using a pH meter (HM-42X, manufactured by DKK-TOA Corporation).

[0057] The hair cleansing agents obtained in each example were evaluated for appearance and viscosity by the methods described below. The results are shown in Tables 1 and 2. The blending amount (mass %) of each component shown in the table is the amount of active ingredient.

[0058] <Appearance at 25℃> Approximately 100 mL of the hair cleanser obtained in each example was filled into a 110 mL transparent glass container, sealed, and left to stand in a constant temperature room at 25°C for at least 24 hours. The appearance of these hair cleansers after storage under the above conditions was judged visually and by measuring the haze value using a TZ7700 simultaneous spectroscopic colorimeter and turbidity analyzer (manufactured by Nippon Denshoku Industries Co., Ltd., 50 mm light path length cell), and judged and evaluated according to the following criteria. [Evaluation criteria] ◎: No precipitate or insoluble matter is visually observed, and the haze value is less than 10% ○: No precipitate or insoluble matter is visually observed, and the haze value is 10% or more but less than 25% ×: Precipitate or insoluble matter is visually confirmed, or the haze value is 25% or more.

[0059] <Appearance at -5°C (low temperature stability)> Approximately 100 mL of the hair cleanser obtained in each example was filled into a 110 mL transparent glass container, sealed, and left to stand in a constant temperature room at -5°C for at least 24 hours. The appearance of these hair cleansers after storage under the above conditions was judged visually and by measuring the haze value using a TZ7700 simultaneous spectrophotometer and turbidity analyzer (manufactured by Nippon Denshoku Industries Co., Ltd., 50 mm light path length cell), and the low temperature stability was evaluated according to the following criteria. [Evaluation criteria] ◎: No precipitate or insoluble matter is visually observed, and the haze value is less than 10% ○: No precipitate or insoluble matter is visually observed, and the haze value is 10% or more but less than 25% ×: Precipitate or insoluble matter is visually confirmed, or the haze value is 25% or more.

[0060] <Viscosity> Approximately 100 mL of the hair cleanser obtained in each example was filled into a 110 mL transparent glass container, sealed, and allowed to stand at 30°C for at least 1 hour. After that, the viscosity was measured using a B-type viscometer (TVB-10, manufactured by Toki Sangyo Co., Ltd.) (rotor No. 3, 12 rpm, 1 minute later).

[0061] [Table 1]

[0062] [Table 2]

[0063] The ingredients listed in the table are as follows: *1: Polyoxyethylene lauryl ether acetic acid (laureth-4 carboxylic acid), Kao Corporation's "Kao Akipo LM-26C" (average number of moles added in formula (I): 2.6) *2: Polyoxyethylene lauryl ether sodium acetate (sodium laureth-4 carboxylate), Kao Corporation's "Kao Akipo LM-26SD" (average number of moles added in formula (I): 2.6) *3: Sodium lauroylmethylalanine, "Alanon ALE" manufactured by Kawaken Fine Chemicals Co., Ltd. *4: Sodium cocoyl glutamate, Ajinomoto Co., Inc. "Amisoft CS-22BE" *5: Sodium methyl cocoyl taurate, NOF Corporation "Diapon K-SF" *6: Sodium lauroyl aspartate, "Aminoformer FLDS-L" manufactured by Asahi Kasei Finechem Co., Ltd. *7: Sodium olefin (C14-C16) sulfonate, Aekyung Chemical Co., Ltd. "ASCO AOS-35(M)" *8: Cocamidomethyl MEA, Kao Corporation's "Aminone C-11S" *9: Cocamide MEA, "Amizol CME" manufactured by Kawaken Fine Chemical Co., Ltd. *10: Lauryl hydroxysultaine: Kao Corporation's "Amphitol 20HD" *11: Lauramidopropyl betaine: Kao Corporation's "Amphitol 20AB" *12: Polyquaternium-10, Kao Corporation's "Kachisero M-80" *13: Benzyl alcohol, Valtris Specialty Chemicals "Benzyl Alcohol (PERFUME GRADE)" *14: Sodium benzoate, Fushimi Pharmaceutical Co., Ltd. "Sodium benzoate solution (35%)" *15: Isodecyl glyceryl ether, Kao Corporation's "Penetol GE-ID" *16: Polyoxyethylene (8) lauryl ether (laureth-6), Kao Corporation's "Emulgen 108" *17:PPG-3 Caprylyl Ether, Kao Corporation's "Kao Sofcare GP-1" *18: Sodium hydroxide, Nankai Chemical Co., Ltd. "48% caustic soda" *19: Citric acid, Showa Kako Co., Ltd. "Citric acid aqueous solution (50%)"

[0064] Tables 1 and 2 show that the hair cleansing agents of the present invention, which contain the specified components in the specified amounts, have excellent low-temperature stability and an appropriate viscosity for a liquid hair cleansing agent. In contrast, the hair cleansing agents of Comparative Example 1, which contains a large amount of component (A), Comparative Example 3, which does not contain component (B), Comparative Examples 2, 4, and 5, which contain a low content of component (B1) in component (B), and Comparative Examples 6 and 7, which do not contain component (C), either have poor low-temperature stability or the viscosity cannot be adequately adjusted for a liquid hair cleansing agent.

Claims

1. The following components (A) to (C): (A) one or more polyoxyalkylene alkyl ether acetic acids and salts thereof, each having an average number of moles of oxyalkylene groups added of more than 0 and not more than 4; (B) one or more selected from the group consisting of N-acylamino acids and salts thereof, and (C) fatty acid N-methylethanolamides, A hair cleanser comprising: the content of the component (A) in the hair wash is 3.0% by mass or more and 11% by mass or less, A hair wash, in which the content of (B1) N-acylalanine and salts thereof in the component (B) is 20% by mass or more.

2. 2. The hair wash according to claim 1, wherein the mass ratio of the component (B) to the component (A) [(B) / (A)] is 0.8 or more and 4.0 or less.

3. The component (A) is a compound represented by the following general formula (I): R １ -O-(R ２ O) ｎ -CH ２ -COOM (I) (In formula (I), R １ represents a linear or branched alkyl group having 8 to 22 carbon atoms, R ２ represents an alkylene group having 2 or 3 carbon atoms, M represents a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium, an alkanolamine or a basic amino acid, and n is the average number of moles added and is a number greater than 0 and equal to or less than 4.

4. The hair wash according to claim 1 or 2, further comprising component (D) an amphoteric surfactant.

5. The hair wash according to claim 4, wherein the component (D) is a betaine surfactant.

6. 3. The hair wash according to claim 1, which has a viscosity at 30°C of 700 mPa·s or more and 4000 mPa·s or less.

7. 3. The hair wash according to claim 1, which has a pH of 4.5 or more and 6.5 or less at 25°C when diluted 20 times by mass with ion-exchanged water.

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