JP2020121945A - Foamable aerosol product and hair washing method - Google Patents

Abstract

To provide a foamable aerosol product that can suppress defoaming of foam formed by a propellant containing carbon dioxide, and a hair washing method.SOLUTION: A foamable aerosol product has a container filled with [A] a stock solution containing N-acylglutamic acid salt, α-olefin sulfonate, and alkyl dimethylamino acetic acid betaine, and [B] a propellant containing carbon dioxide, and is used for hair washing.SELECTED DRAWING: None

Description

The present invention relates to effervescent aerosol products and hair cleaning methods.

2. Description of the Related Art In recent years, foamable aerosol products have been widely used, in which a stock solution is filled in a container together with a propellant for convenience of use and bubbles formed after being sprayed from the container are applied to hair.
Of these, attention has been paid to the blood circulation promoting effect of carbon dioxide (carbon dioxide gas). Carbon dioxide is filled in a container as one component of the propellant in the foamable aerosol product as described above, and the injection from this container There has been proposed a technique for treating hair by using foamed foam (see JP-A-2014-111560).

JP, 2014-111560, A

By the way, in the foamable aerosol product in which carbon dioxide is contained in the propellant, the foam formed by spraying from the container is easily defoamed on the hair, and there is room for improvement in suppressing defoaming.

In view of the above circumstances, an object of the present invention is to provide a foamable aerosol product and a hair cleaning method capable of suppressing defoaming of foam formed by a propellant containing carbon dioxide.

The present inventor has conducted extensive studies to suppress defoaming when washing hair using a foam formed by foaming with a propellant containing carbon dioxide, and as a result, N-acyl glutamate and α-olefin sulfonate. , And that the alkyldimethylaminoacetic acid betaine was blended in the stock solution was significant, and the present invention was completed.

That is, the foamable aerosol product according to the present invention is a foamable aerosol product used for hair washing,
A container was filled with a propellant containing [A] N-acylglutamate, an α-olefinsulfonate, and betaine alkyldimethylaminoacetate, and [B] carbon dioxide.

The stock solution [A] is preferably one containing charcoal. This is excellent in cleansing the scalp (removing oil) while suppressing defoaming.

It is preferable that the total amount of the anionic surfactant and the amphoteric surfactant in the stock solution [A] is 15% by mass or less. Here, as the undiluted solution, neither an anionic surfactant other than the three components of N-acylglutamate, α-olefinsulfonate, and betaine alkyldimethylaminoacetate and an amphoteric surfactant were blended. Alternatively, only one of them may be blended. As described above, the total amount of the anionic surfactant (including N-acylglutamate and α-olefinsulfonate) and the amphoteric surfactant (including alkyldimethylaminoacetic acid betaine) in the undiluted solution is 15% by mass or less. By doing so, it becomes possible to suppress the irritation given to the scalp at the time of hair washing.

The hair washing method according to the present invention cleans hair using the foamable aerosol product.

According to the present invention, it is possible to suppress defoaming when hair is washed using foam formed by foaming with a propellant containing carbon dioxide.

Hereinafter, the present invention will be described with reference to the foamable aerosol product and the hair cleaning method of the present embodiment as examples.
The foamable aerosol product of the present embodiment is a foamable aerosol product used for hair washing,
A container was filled with a propellant containing [A] N-acylglutamate, an α-olefinsulfonate, and betaine alkyldimethylaminoacetate, and [B] carbon dioxide.

([A] undiluted solution)
The stock solution [A] contains N-acylglutamate, α-olefinsulfonate, and betaine alkyldimethylaminoacetate (the content of water in the stock solution [A] is, for example, 70% by mass or more). is there.).
By blending the above-mentioned three components in the stock solution, defoaming is suppressed in foaming when the hair is washed using the foam formed by the propellant containing carbon dioxide. As a result, the hairs are prevented from being caught with each other during the hair washing, and the operability of the hair washing is improved. In addition, when scalp massage is also performed in the hair washing, the operability is improved by preventing the hairs from being caught during the massage.
Further, by blending the above three components in the stock solution, it is possible not only to improve the quality of the foam even after foaming when performing hair washing using the foam formed by the propellant containing carbon dioxide. A sufficient amount can be secured.
In addition, the stock solution [A] may optionally be mixed with a known material as a raw material for a hair cleansing agent such as shampoo as long as the effect of the present invention is not impaired.

［上記一般式（１）において、Ｒ^１は、直鎖の飽和又は不飽和の炭素数８以上２２以下の炭化水素基を表す。また、Ｘ及びＹは、水素、ナトリウム、カリウム、トリエタノールアミンを表す。なお、Ｘ及びＹが両方とも水素となることはない。］ (N-acyl glutamate)
The N-acyl glutamate is represented by the following general formula (1).

[In the general formula (1), R ¹ represents a straight-chain saturated or unsaturated hydrocarbon group having 8 or more and 22 or less carbon atoms. Moreover, X and Y represent hydrogen, sodium, potassium, and triethanolamine. Note that neither X nor Y is hydrogen. ]

Examples of the N-acyl glutamate include capryloyl glutamate (eg, capryloyl glutamate 2Na), N-cocoyl glutamate (eg, cocoyl glutamate 2Na, cocoyl glutamate Na, cocoyl glutamate K, cocoyl glutamate TEA), N-lauroyl glutamate (eg Na lauroyl glutamate, 2 Na lauroyl glutamate, K lauroyl glutamate, TEA lauroyl glutamate etc.), N-myristoyl glutamate (eg Na myristoyl glutamate, myristoyl glutamate K etc.), N-palmitoyl glutamate, N-stearoyl glutamate (eg, 2Na stearoyl glutamate, Na stearoyl glutamate, K stearoyl glutamate K, etc.), N-oleoyl glutamate, N-palm fatty acid glutamate (eg, palm fatty acid glutamate Na, etc.), N-olive oil fatty acid glutamate Examples thereof include salts (eg, olive oil fatty acid Na glutamic acid).

By blending N-acyl glutamate with the stock solution [A] of the foamable aerosol product of the present embodiment, a foamy foam formed from the foamable aerosol product has a creamy (mostly fine foam) quality. realizable.

One or two or more of the above-mentioned N-acylglutamates are blended in the stock solution [A].
The lower limit of the amount of the N-acylglutamate compounded in the stock solution [A] is preferably 0.5% by mass or more, and more preferably 1% by mass or more, from the viewpoint of providing a creamy (more fine bubbles) foam quality. In addition, the upper limit of the amount of the N-acylglutamate compounded in the stock solution [A] is preferably 10% by mass or less, and more preferably 5% by mass or less, from the viewpoint of further improving the foam retention.

(Α-olefin sulfonate)
The α-olefin sulfonate is a salt addition product of an alkyl sulfonic acid in which an α-olefin having 10 to 20 carbon atoms is sulfonated.
Examples of the α-olefin sulfonate include Na olefin (C12-14) sulfonate, Na olefin (C14-16) sulfonate, Na olefin (C14-18) sulfonate, sodium tetradecene sulfonate, and the like. ..

By blending the [A] stock solution of the foamable aerosol product of the present embodiment with the α-olefin sulfonate, the quick foaming property when foaming is formed from the foamable aerosol product becomes excellent.

The [A] stock solution is blended with one or more of the above α-olefin sulfonates.
The lower limit of the blending amount of the α-olefin sulfonate in the undiluted solution [A] is preferably 0.5% by mass or more from the viewpoint of further improving the quick foaming property when foaming is formed from the foamable aerosol product. 1 mass% or more is more preferable. In addition, the upper limit of the blending amount of the α-olefin sulfonate in the stock solution [A] is preferably 10% by mass or less, and more preferably 6% by mass or less, from the viewpoint of making the hair feel softer during hair washing. ..

［上記一般式（２）において、Ｒ^２は、アルキル基を表し、例えば、炭素数１０以上１８以下の直鎖状アルキル基である。］ (Alkyldimethylaminoacetic acid betaine)
The alkyldimethylaminoacetic acid betaine is represented by the following general formula (2).

[In the general formula (2), R ² represents an alkyl group, and is, for example, a linear alkyl group having 10 to 18 carbon atoms. ]

Specific examples of the alkyldimethylaminoacetic acid betaine include, for example, lauryldimethylaminoacetic acid betaine, stearyldimethylaminoacetic acid betaine, cetyldimethylaminoacetic acid betaine, myristyldimethylaminoacetic acid betaine, and the like.

When the undiluted solution [A] of the effervescent aerosol product of the present embodiment is blended with alkyldimethylaminoacetic acid betaine, excellent foam retention in hair washing is achieved.

[A] The stock solution is blended with one or more of the above alkyldimethylaminoacetic acid betaines.
The lower limit of the blending amount of alkyldimethylaminoacetic acid betaine in the stock solution [A] is preferably 0.5% by mass or more and more preferably 2% by mass or more from the viewpoint of further improving the foam retention in hair washing. In addition, the upper limit of the amount of the alkyldimethylaminoacetic acid betaine mixed in the stock solution [A] is preferably 10% by mass or less, and more preferably 8% by mass or less, from the viewpoint of making the hair feel softer during hair washing.
In addition, the amount of alkyldimethylaminoacetic acid betaine mixed in the stock solution [A] may be larger than the amount of N-acylglutamate and the amount of α-olefinsulfonate.

(Arbitrary raw material in undiluted solution)
As described above, the stock solution [A] optionally contains the raw materials used for known hair cleansing agents such as shampoos. This arbitrary raw material is a component other than the above three components, and examples thereof include charcoal, amphoteric surfactant, anionic surfactant, nonionic surfactant, cationic polymer, polyhydric alcohol, cooling agent, acid, lower alcohol, It may contain components such as sugars, polymer compounds, amino acids, animal and plant extracts, inorganic compounds, fragrances and preservatives. In addition, you may use each arbitrary component individually or in combination of 2 or more types.

The charcoal refers to a dried carbide obtained by heating or the like from wood or bamboo. By blending charcoal, sebum stains on the scalp and pores can be adsorbed, and a scalp cleansing effect can be obtained.
The charcoal is not particularly limited as long as it can be blended with an effervescent aerosol product, and examples thereof include activated carbon, medicinal charcoal, tung charcoal, cedar charcoal, bamboo charcoal, bincho charcoal, hinoki charcoal and the like. From the viewpoint of improving cleansing of the scalp, it is preferable to use powdery one. The upper limit of the volume average particle diameter of charcoal is not particularly limited, but is, for example, 50 μm. The value of the volume average particle diameter of the charcoal can be measured by a laser diffraction/scattering method (as a measuring device, for example, "Microtrac MT3000" manufactured by Nikkiso Co., Ltd. can be used). By setting the upper limit of the volume average particle diameter of charcoal to 50 μm, operability during hair washing can be improved, and clogging of the injection port of the foamable aerosol product can be suppressed. The lower limit of the volume average particle diameter of charcoal is, for example, 0.5 μm.
The lower limit of the content of charcoal in the stock solution [A] is not particularly limited, but may be 0.010 mass% or more, for example. Here, from the viewpoint of sufficiently suppressing the decrease in the amount of foam after foaming during hair washing and improving the foam retention, the content of charcoal in the stock solution [A] is 0.4% by mass or less. preferable. From the viewpoint of improving the foam quality after foaming during hair washing, the content of charcoal in the stock solution [A] is preferably 0.025 mass% or more.

Examples of amphoteric surfactants other than alkyldimethylaminoacetic acid betaine include, for example, amide propyl such as coconut oil fatty acid amide propyl betaine, lauric acid amide propyl betaine, isostearic acid amide propyl betaine, linoleic acid amide propyl and palm kernel fatty acid amide propyl betaine. Amidoalkyl betaine-type amphoteric surfactants including betaine-type amphoteric surfactants; N-coconut oil fatty acid acyl-N'-carboxyethyl-N'-hydroxyethylethylenediamine sodium, 2-alkyl-N-carboxymethyl-N-hydroxy. Imidazoline type amphoteric surfactants such as ethyl imidazolinium betaine, undecyl-N-hydroxyethyl-N-carboxymethyl imidazolinium betaine; N-alkyl-N,N-dimethylammonium-N-propyl sulfonate sodium, N- Sulfobetaine type such as sodium alkyl-N,N-dimethylammonium-N-(2-hydroxypropyl)sulfonate and sodium N-fatty acid amidopropyl-N,N-dimethylammonium-N-(2-hydroxypropyl)sulfonate Amphoteric surfactants; amidoamine oxide type amphoteric surfactants such as lauric acid amidopropyldimethylamine oxide; and the like.

Examples of the anionic surfactant other than the N-acyl glutamate and the α-olefin sulfonate include, for example, an acyl amino acid other than N-acyl glutamate or a salt thereof (for example, acyl aspartic acid or a salt thereof, acyl alanine or a salt thereof). Salt, acylmethylalanine or a salt thereof, acylglycine or a salt thereof, etc.; coconut oil fatty acid or a salt thereof (sodium salt, potassium salt etc.), cocoyl isethionic acid or a salt thereof (sodium salt, potassium salt etc.); polyoxy Ethylene lauryl ether sulfuric acid or its salt (sodium salt, potassium salt, etc.); Polyoxyethylene lauryl ether acetic acid or its salt (sodium salt, potassium salt, etc.); Alkylsulfosuccinic acid disodium; Polyoxyethylene sulfosuccinic acid or its salt (sodium) Salt, potassium salt, etc.); sodium lauroyl hydrolyzed silk; isostearic acid hydrolyzed silk AMP (2-amino-2-methyl-1-propanol salt of a condensate of isostearic acid and hydrolyzed silk); cocoyl hydrolyzed soy protein Potassium; salts of cocoyl hydrolyzed collagen (sodium salt, potassium salt, etc.); polyoxyethylene lauryl ether phosphate or salts thereof (sodium salt, potassium salt, etc.) and the like.

The total amount of the anionic surfactant (including N-acylglutamate and α-olefinsulfonate) and the amphoteric surfactant (including alkyldimethylaminoacetic acid betaine) in the stock solution [A] was 15 mass. % Or less is preferable. This makes it possible to reduce the irritation given to the scalp during hair washing. Further, even when the total amount of the compounded ingredients is suppressed to 15% by mass or less to suppress irritation to the scalp, the N-acylglutamate salt, the α-olefinsulfonate salt, and the alkyldimethylamino acid in the stock solution [A] are contained. By incorporating betaine acetate, defoaming during hair washing can be suppressed.
Further, from the viewpoint of suppressing the irritation to the scalp to be small, the anionic surfactant (including N-acylglutamate and α-olefinsulfonate) and the amphoteric surfactant (alkyldimethylaminoacetic acid betaine) in the stock solution [A] are used. It is more preferable that the total of the compounding amounts of (including) and the nonionic surfactant is 15% by mass or less.

As the nonionic surfactant, for example, polyoxyethylene alkyl ether, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol tetra fatty acid ester, glycerin fatty acid ester, polyoxyethylene sorbitol Examples thereof include oxyethylene glycerin fatty acid ester, alkyl glucoside, sorbitan fatty acid ester, polyglycerin fatty acid ester, and sucrose fatty acid ester. [A] The stock solution may be blended with one or more nonionic surfactants, and the blending amount of the nonionic surfactant in the [A] stock solution is, for example, 0.1% by mass or more and 5% by mass or less. is there.

Examples of the cationic polymer include cationized cellulose, cationized guar gum, vinylpyrrolidone/N,N-dimethylaminoethylmethacrylic acid copolymer diethyl sulfate, acrylamide/acrylic acid/dimethyldiallylammonium chloride copolymer, N , N-dimethylaminoethyl diethyl methacrylate sulfate/N,N-dimethylacrylamide/polyethylene glycol dimethacrylate copolymer. By blending the cationic polymer with the stock solution [A], it is possible to improve the finger-passing property when the foam formed by foaming the foamable aerosol product is washed from the hair. [A] The undiluted solution may be mixed with one or more kinds of cationic polymers, and the amount of the cationic polymer in the [A] undiluted solution is, for example, 0.1% by mass or more and 1% by mass or less. ..

Examples of the polyhydric alcohol include ethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, 1,3-butylene glycol, glycerin and polyglycerin. One or more polyhydric alcohols may be blended in the [A] stock solution, and the blending amount of the polyhydric alcohol in the [A] stock solution is, for example, 0.01% by mass or more and 5% by mass or less.

Examples of the cooling agent include menthol. You may mix|blend 1 type, or 2 or more types of cooling agents with [A] stock solution, and the compounding quantity of the cooling agent in [A] stock solution is 0.05 mass% or more and 1 mass% or less, for example.

Examples of the acid include organic acids such as malic acid, lactic acid, tartaric acid, citric acid, succinic acid and glycolic acid; inorganic acids such as phosphoric acid, sulfuric acid and hydrochloric acid; One or two or more kinds of acids may be blended in the [A] stock solution, and the blending amount of the acid in the [A] stock solution is, for example, 0.1% by mass or more and 1.5% by mass or less.

(Formulation)
The stock solution [A] is preferably liquid. When the viscosity of the liquid [A] stock solution is measured using a B-type viscometer (temperature: 25° C., rotor: appropriately set according to viscosity, rotor rotation speed: 60 rpm), 60 seconds from the start of viscosity measurement The value after elapse is preferably 10 mPa·s or more and 20,000 mPa·s or less, more preferably 20 mPa·s or more and 15,000 mPa·s or less, and further preferably 30 mPa·s or more and 12,000 mPa·s or less.

(PH)
The pH of the stock solution [A] is preferably weakly acidic. By keeping the pH weakly acidic, it is possible to suppress the carbon dioxide from becoming a carbonate and enhance the blood circulation promoting effect, and it is possible that the foamability and the dischargeability are deteriorated due to the increase in viscosity due to the decrease in pH. Can be suppressed. The pH of the stock solution [A] is preferably 4.0 or more and 6.8 or less, and more preferably 4.5 or more and 6.5 or less.

(Chloride ion concentration)
The chloride ion concentration of the stock solution [A] is preferably 500 mass ppm or less from the viewpoint of suppressing the corrosion of the container described later.
The chloride ion concentration refers to an analysis value by an ion chromatograph (for example, by using a Dionex "ICS-2000" equipped with a Dionex anion exchange column "IonPac AS18", the chloride ion concentration The analytical value is obtained.).

([B] propellant)
The container of the foamable aerosol product of the present embodiment is filled with [B] propellant. The [B] propellant foams the [A] stock solution ejected from the container.

[B] The propellant contains carbon dioxide. As a result, carbon dioxide can be included in the foamed foam, so that blood circulation in the scalp can be promoted and cleansing (removal of oil) of the scalp can be performed.
In the foamable aerosol product of the present embodiment, the concentration of carbon dioxide filled in the container is 0.8% by mass or more, 1.0% by mass or more is preferable, and 1.1% by mass or more is preferable. Further, the concentration of carbon dioxide filled in the container can be, for example, 3.0% by mass or less. Here, the concentration of carbon dioxide filled in the container is calculated by “(carbon dioxide)/([A] stock solution and [B] propellant filled in container)×100”.

The [B] propellant may further contain one kind or two or more kinds as components other than carbon dioxide. Such components include, for example, liquefied petroleum gas (LPG), isopentane, dimethyl ether, nitrogen and mixtures thereof.
The liquefied petroleum gas is not particularly limited, but may be, for example, propane and n-butane (normal butane), propane and i-butane (isobutane), or propane, n-butane and i-butane. Liquefied petroleum gas is speculated to contribute to the initial foaming property due to its high volatility.
Isopentane is speculated to contribute to the persistence of the foam when removed from the container. When isopentane is filled together with the liquefied gas, the amount of the liquefied gas is preferably larger than that of isopentane in order to improve the foamability.

The propellant [B] may be composed of carbon dioxide only, but it is preferable to use both carbon dioxide and liquefied petroleum gas from the viewpoint of exhausting the contents as much as possible while obtaining the blood circulation promoting effect.
In addition, as compared with the foam formed by foaming with a propellant other than carbon dioxide, the foam containing carbon dioxide may be defoamed by the hair washing operation, but as described above, [A] The defoaming can be suppressed by mixing the three components in the stock solution.

The propellant [B] is preferably 0.5 parts by mass or more and 30 parts by mass or less, more preferably 1 part by mass or more and 20 parts by mass or less, and further preferably 2 parts by mass or more and 15 parts by mass or less with respect to 100 parts by mass of the stock solution. preferable. By setting the filling amount of the propellant within the above range, the undiluted solution can be efficiently ejected.

(container)
The container in the foamable aerosol product of the present embodiment may be a known pressure-resistant container, and the material thereof is, for example, a metal such as aluminum, aluminum alloy, tin plate, or steel. Further, the surface of the metal container may be plated. Further, this container may have a resin layer laminated on the inner surface or may have an inner bag inside. Furthermore, this container may or may not have an inner bag filled with [A] stock solution and [B] propellant inside.

(Gauge pressure)
From the viewpoint of safety, the gauge pressure of the container in the foamable aerosol product of the present embodiment is 0.80 MPa or less at a temperature condition of 25° C., and preferably 0.65 MPa or less.

(Use and hair washing method)
The effervescent aerosol product of the present embodiment can be used not only for shampoo but also for hair washing applications in which the treatment time is relatively long compared to shampoos such as scalp massage and scalp spa. A hair cleaning method is provided. The hair washing includes washing of hair and scalp. Here, the treatment time of scalp massage, scalp spa, etc. is 5 minutes or more and 20 minutes or less, for example.
When performing hair washing, scalp massage, scalp spa, etc. using the foam formed by foaming the foamable aerosol product of the present embodiment, the bubbles are hard to disappear during the period from the procedure to the procedure. Since the finger passage is improved and the squeezing of the hair during washing can be reduced, it is easy to perform the treatment.

Hereinafter, the present invention will be specifically described based on Examples, but the present invention is not limited to these Examples.

(Preparation of undiluted solution)
Stock solutions (A-1 to A-4 and B-1 to B-4) were prepared by mixing the components shown in Table 1, Table 3 and Table 5 with water.
As the N-acyl glutamate, sodium N-coconut oil fatty acid acyl-L-glutamate is used, as the α-olefin sulfonate, sodium tetradecene sulfonate, and as the alkyl dimethyl amino acetic acid betaine, lauryl dimethyl amino acetic acid. Betaine was used.

(Preparation of Examples 1 to 4, Comparative Example 1, and Reference Examples A to C)
Each of the stock solutions prepared above and the propellant were mixed so that the propellant was 7.1 parts by mass with respect to 92.9 parts by mass of the stock solution, and the mixture was filled in a pressure vessel made of aluminum. As shown in Tables 4 and 6, the foamable aerosol products of Examples 1 to 4, Comparative Example 1, and Reference Examples A to C were obtained. The composition of the propellant was isopentane 1.1 parts by mass, LPG 4.8 parts by mass, and carbon dioxide 1.2 parts by mass.

(Evaluation of foam state after discharge (before foaming))
The evaluation of the state of foam after discharge (before foaming) was performed by the following evaluation method and evaluation criteria.

(Evaluation method)
By discharging 3 g of the content from each of the foamable aerosol products of Examples 1 to 4, Comparative Example 1 and Reference Examples A to C, and comparing the discharged foam-like discharge product with a reference, The state (the amount of foam (the size of the entire foam)) was visually evaluated. The results of each evaluation were obtained by a panel of three panelists who evaluate them on a daily basis.

(Evaluation criteria)
◯: The amount of bubbles is large as compared with the standard.
-: The amount of bubbles is equivalent to that of the standard.
X: The amount of bubbles is small as compared with the standard.

(Evaluation of foam amount after foaming and foam quality after foaming)
Each evaluation of the amount of foam after foaming and the quality of foam after foaming was performed by the following evaluation methods and evaluation criteria.

After randomly rinsing the hair with warm water to a Japanese woman with randomly selected hair that is longer than the shoulder, apply different foaming aerosol product exhalations to the left and right half of the woman's head. did. Specifically, one wet hair was coated with 3 g of the foam-like discharge product discharged from the foamable aerosol product (Example 1 or Comparative Example 1) as a reference, and the other wet hair was evaluated. 3 g of the foam-like discharge product discharged from the foamable aerosol products of Examples 1 to 4, Comparative Example 1 and Reference Examples A to C were applied, and the reference and evaluation-target foam-like discharge products were not mixed. Thus, foaming was performed with a finger for about 2 minutes. After the foaming was completed, the amount and quality of the foam present on the left and right hairs were visually evaluated (evaluation of "foam amount after foaming" and "foam quality after foaming"). The results of each evaluation were obtained by a panel of three panelists who evaluate them on a daily basis.

(Evaluation criteria)
The evaluation criteria of the amount of foam after foaming and the quality of foam after foaming are shown below.

Amount of foam after foaming ○: The amount of foam is larger than the standard.
-: The amount of bubbles is equivalent to that of the standard.
X: The amount of bubbles is small as compared with the standard.

Foam quality after whipping ◯: Excellent in creaminess of foam (the amount of fine bubbles) compared to the standard.
-: Compared with the standard, the creaminess of bubbles (the amount of fine bubbles) is equivalent.
X: Inferior in creaminess of foam (amount of fine bubbles) as compared with the standard.

(Evaluation of foam retention)
The foam retention was evaluated by the following evaluation method and evaluation criteria.

(Evaluation method)
A plurality of hair bundles having a length of 45 cm and a weight of 7.5 g were prepared from Japanese hair of the same person who had been subjected to a hair dyeing treatment and whose hair tips had been damaged. After rinsing the above-mentioned hair bundle with warm water for about 5 seconds, foam-like discharge discharged from the foamable aerosol products of Examples 1 to 4, Comparative Example 1 and Reference Examples AC to each wet hair bundle. 0.5 g of the product was applied to the hair bundle, and the hair bundle was foamed with a finger for 30 seconds. After foaming, the mixture was allowed to stand for 2 minutes, the bubbles remaining in the hair bundle were scraped off, and the whole amount was transferred to a 50 mL or 200 mL graduated cylinder, and the transferred foam was evaluated according to the following evaluation criteria. The evaluation was performed by one panelist who evaluates on a daily basis.

(Evaluation criteria)
○: The amount of bubbles transferred to the graduated cylinder is larger than that of the standard.
Equal: Equal amount of foam transferred to the graduated cylinder compared to the standard.
X: The amount of bubbles transferred to the graduated cylinder is smaller than that of the standard.

It was confirmed that the above-mentioned Example 1 was excellent in the amount of foam after foaming, the foam quality, and the foam retention when Comparative Example 1 was used as a reference. Particularly, in Example 1, the total amount of the amphoteric surfactant and the anionic surfactant blended in the stock solution was smaller than that in Comparative Example 1, and irritation to the scalp was suppressed to a small level, but It was superior to Comparative Example 1 in foam amount, foam quality, and foam retention.
During the treatment, it was confirmed that the amount of bubbles on the hair decreased in Comparative Example 1, but it was confirmed that the amount of bubbles on the hair was maintained or increased in Example 1.

According to the above-mentioned Example 2-3, even when charcoal (Bincho charcoal having a volume average particle diameter of 50 μm or less) is mixed in the stock solution, the amount of foam after foaming, foam quality, and foam are the same as in Example 1. It was confirmed to be excellent in holding.
According to Example 4, when the amount of charcoal blended in the stock solution was large, the foam quality after foaming was excellent, but the foam amount and foam retention after foaming were poor. However, it was confirmed that Example 4 was superior to Comparative Example 1 not only in foam quality after foaming but also in foam amount and foam retention after foaming (not shown in the table).

In Reference Examples A to C, the total compounding amount of the amphoteric surfactant and the anionic surfactant was the same as that of Comparative Example 1 (the amphoteric surfactant is not compounded, so the anionic surfactant is not mixed). The amount of the anionic surfactant was changed and the type and amount of the anionic surfactant were verified, and it was confirmed that the foam quality and the foam amount after foaming were inferior to those of Comparative Example 1.

Claims (4)

A foamable aerosol product used for hair washing,
[A] A stock solution containing N-acylglutamate, α-olefinsulfonate, and betaine alkyldimethylaminoacetate, and [B] a foamable aerosol product in which a container is filled with a propellant containing carbon dioxide. The foamable aerosol product according to claim 1, wherein charcoal is added to the stock solution. The foamable aerosol product according to claim 1 or 2, wherein the total amount of the anionic surfactant and the amphoteric surfactant blended in the stock solution is 15% by mass or less. A hair washing method for washing hair using the foamable aerosol product according to claim 1.