JP7520466B2 - Hair removal composition - Google Patents

Description

The present invention relates to a hair removal composition.

Hair removal compositions containing thioglycolic acid and/or its salts as a hair removal ingredient are widely used. In these hair removal compositions, thioglycolic acid and/or its salts reduce the disulfide bonds in the keratin that constitutes body hair, thereby exerting a hair removal effect.

The above hair removal composition is generally produced by emulsifying the hair removal component, oily component, and water using an emulsifier.

The following Patent Document 1 discloses a hair removal agent that contains thioglycolic acid or a thioglycolate salt and silicone oil.

The following Patent Document 2 discloses a cream-type hair remover composition that contains thioglycolic acid, sodium hydroxide, calcium hydroxide, a polyoxyethylene alkyl ether having an HLB of 13 or more, an oily substance selected from the group consisting of cetyl alcohol, stearyl alcohol, liquid paraffin, and solid paraffin, and water. This cream-type hair remover composition contains each of the above-mentioned components in specific amounts.

Japanese Patent Application Publication No. 11-246372 Japanese Patent Application Publication No. 5-170624

After the hair removal composition is manufactured by mixing the various components, it may be stored in a specified container (e.g., a drum) for the purpose of storage or transportation. However, if the viscosity of the hair removal composition immediately after manufacture is too high, it may be difficult to pour into the container, or it may take a long time to pour. On the other hand, if the viscosity of the hair removal composition immediately after manufacture is too low, foaming is likely to occur when poured into a container. For this reason, from the viewpoint of the manufacturing process, it is important that the hair removal composition immediately after manufacture has an appropriate viscosity.

Furthermore, conventional hair removal compositions such as those described in Patent Document 1 contain a relatively large amount of salts. Therefore, it is difficult to increase the emulsion stability of conventional hair removal compositions, and it is particularly difficult to increase the emulsion stability in a high-temperature environment. The hair removal composition described in Patent Document 2 can increase the emulsion stability to a certain extent in a room temperature environment. However, it is difficult to increase the emulsion stability in a high-temperature environment even with the hair removal composition described in Patent Document 2.

The object of the present invention is to provide a hair removal composition that can improve the viscosity immediately after production and can enhance the emulsion stability in a high-temperature environment.

The present invention provides a hair removal composition that contains the following components (A), (B), (C), and (D), and in which the mass ratio of the content of component (C) to the content of component (D) is 0.2 or more and 1.5 or less.

Component (A): thioglycolic acid and/or a salt thereof Component (B): polyoxyethylene alkyl ether phosphate Component (C): polyoxyethylene alkyl ether having an HLB value of 12.0 or more Component (D): polyoxyethylene alkyl ether having an HLB value of less than 12.0

The hair removal composition of the present invention preferably has a pH of 12 or higher.

The hair removal composition of the present invention contains specific component (A), specific component (B), specific component (C), and specific component (D), and the mass ratio of the content of component (C) to the content of component (D) is 0.2 or more and 1.5 or less, so that the viscosity immediately after production can be made good and the emulsion stability in a high-temperature environment can be increased.

The present invention is described in detail below.

The hair removal composition of the present invention contains thioglycolic acid and/or a salt thereof, polyoxyethylene alkyl ether phosphate, a polyoxyethylene alkyl ether having an HLB value of 12.0 or more, and a polyoxyethylene alkyl ether having an HLB value of less than 12.0.

In this specification, the above-mentioned "thioglycolic acid and/or its salt" may be referred to as "component (A)."

In this specification, the above-mentioned "polyoxyethylene alkyl ether phosphate" may be referred to as "component (B)."

In this specification, the above-mentioned "polyoxyethylene alkyl ether having an HLB value of 12.0 or more" may be referred to as "component (C)."

In this specification, the above-mentioned "polyoxyethylene alkyl ether having an HLB value of less than 12.0" may be referred to as "component (D)."

The HLB values of components (C) and (D) can be determined by actual measurement.

Therefore, the hair removal composition of the present invention contains components (A), (B), (C), and (D). In the hair removal composition of the present invention, the mass ratio of the content of component (C) to the content of component (D) (content of component (C)/content of component (D)) is 0.2 or more and 1.5 or less.

The hair removal composition of the present invention has the above-mentioned configuration, which allows for good viscosity immediately after production and improved emulsion stability in high-temperature environments.

The present inventors have found that by using component (B) in a hair removal composition containing component (A), it is possible to improve the emulsion stability in a high-temperature environment. However, if component (B) is simply used, the shape of the emulsion becomes non-uniform, and the viscosity of the hair removal composition immediately after production tends to be excessively low. The present inventors have found that by using components (C) and (D) in a specific mass ratio in addition to component (B), it is possible to improve the viscosity of the hair removal composition immediately after production while maintaining high emulsion stability in a high-temperature environment.

In addition, the hair removal composition of the present invention can suppress changes in viscosity of the hair removal composition after storage, compared to the viscosity of the hair removal composition immediately after production. Therefore, the hair removal composition of the present invention can also provide good viscosity during use. Therefore, the hair removal composition of the present invention is less likely to drip when applied to a target, and is also less likely to cause uneven hair removal.

The hair removal composition of the present invention contains at least component (A), component (B), component (C), and component (D). The hair removal composition of the present invention may contain other components in addition to component (A), component (B), component (C), and component (D).

The above components, such as component (A), component (B), component (C), component (D) and other components, may each be used alone or in combination of two or more.

In this specification, the content of each component means the total content of all of the components contained in the hair removal composition. For example, the content of component (C) means the total content of all components (C) in the hair removal composition.

The following describes in detail each of the components used in the hair removal composition of the present invention.

(Component (A))
Component (A) is thioglycolic acid and/or a salt thereof. Component (A) is a depilatory component. The above-mentioned depilatory composition may contain thioglycolic acid, a thioglycolic acid salt, or both thioglycolic acid and a thioglycolic acid salt as component (A). Only one type of component (A) may be used, or two or more types may be used in combination.

Examples of the thioglycolate salts include calcium thioglycolate, sodium thioglycolate, potassium thioglycolate, magnesium thioglycolate, ammonium thioglycolate, monoethanolamine thioglycolate, and triethanolamine thioglycolate.

In 100% by mass of the above hair removal composition, the content of component (A) in terms of a thioglycolic acid structure is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, even more preferably 2.0% by mass or more, preferably 10.0% by mass or less, and more preferably 8.0% by mass or less. When the content of component (A) in terms of a thioglycolic acid structure is equal to or more than the above lower limit, the hair removal power can be further increased. When the content of component (A) in terms of a thioglycolic acid structure is equal to or less than the above upper limit, the hair removal power and storage stability can be increased, and skin irritation can be reduced.

The above content in terms of thioglycolic acid structure means the content of thioglycolic acid when component (A) is thioglycolic acid, and means the content represented by the following formula when component (A) is a thioglycolic acid salt. In addition, the above content in terms of thioglycolic acid structure means the sum of the content of thioglycolic acid and the content represented by the following formula when component (A) contains both thioglycolic acid and a thioglycolic acid salt.

Thioglycolic acid salt content (mass%) calculated as thioglycolic acid structure = thioglycolic acid salt content (mass%) x (molecular weight of thioglycolic acid/molecular weight of thioglycolic acid salt)

(Component (B))
Component (B) is a polyoxyethylene alkyl ether phosphate. By using component (B), it is possible to improve emulsion stability in a high temperature environment. Component (B) may be used alone or in combination of two or more.

Examples of component (B) include polyoxyethylene lauryl ether phosphate, polyoxyethylene myristyl ether phosphate, polyoxyethylene cetyl ether phosphate, polyoxyethylene stearyl ether phosphate, and polyoxyethylene oleyl ether phosphate.

From the viewpoint of further improving emulsion stability in a high-temperature environment, it is preferable that component (B) contains polyoxyethylene cetyl ether phosphate and/or polyoxyethylene stearyl ether phosphate.

From the viewpoint of further improving emulsion stability in a high-temperature environment, the average number of moles of ethylene oxide (EO) added in component (B) (average number of moles of EO added in the polyoxyethylene portion) is preferably 3 or more, more preferably 5 or more, and preferably 60 or less, more preferably 40 or less, and even more preferably 25 or less.

From the viewpoint of further improving emulsion stability in a high-temperature environment, the number of carbon atoms in the alkyl group of component (B) is preferably 12 or more, more preferably 14 or more, and preferably 22 or less, more preferably 20 or less.

In 100% by mass of the above hair removal composition, the content of component (B) is preferably 0.5% by mass or more, more preferably 0.8% by mass or more, even more preferably 1.0% by mass or more, preferably 5.0% by mass or less, more preferably 4.0% by mass or less, and even more preferably 3.0% by mass or less. When the content of component (B) is equal to or more than the above lower limit, the emulsion stability in a high-temperature environment can be further improved. When the content of component (B) is equal to or less than the above upper limit, the production cost can be reduced.

(Component (C))
Component (C) is a polyoxyethylene alkyl ether having an HLB value of 12.0 or more. By using component (C) in combination with component (B) and component (D), the effects of the present invention can be achieved. Component (C) may be used alone or in combination of two or more.

The HLB value of component (C) is 12.0 or more. The HLB value of component (C) is preferably 14.0 or more, more preferably 16.0 or more, and preferably 20.0 or less.

Examples of component (C) include polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene myristyl ether, polyoxyethylene octyldodecyl ether, and polyoxyethylene behenyl ether.

From the viewpoint of exerting the effects of the present invention more effectively, the average number of moles of ethylene oxide (EO) added in component (C) (average number of moles of EO added in the polyoxyethylene portion) is preferably 10 or more, more preferably 15 or more, and preferably 50 or less.

In this specification, the number of carbon atoms in the alkyl group of component (C) is 6 or more. From the viewpoint of more effectively exerting the effects of the present invention, the number of carbon atoms in the alkyl group of component (C) is preferably 12 or more, more preferably 14 or more, and preferably 22 or less.

The mass ratio of the content of component (C) to the content of component (D) (content of component (C)/content of component (D)) is 0.2 or more and 1.5 or less. If the mass ratio (content of component (C)/content of component (D)) is less than 0.2, the emulsion stability in a high-temperature environment is likely to decrease. If the mass ratio (content of component (C)/content of component (D)) exceeds 1.5, it is difficult to improve the viscosity of the hair removal composition immediately after production.

The mass ratio of the content of component (C) to the content of component (D) (content of component (C)/content of component (D)) is preferably 0.4 or more, more preferably 0.5 or more, and preferably 1.2 or less, more preferably 0.8 or less. When the mass ratio (content of component (C)/content of component (D)) is equal to or greater than the lower limit, the emulsion stability in a high-temperature environment can be further improved. When the mass ratio (content of component (C)/content of component (D)) is equal to or less than the upper limit, the viscosity of the hair removal composition immediately after production can be further improved.

In 100% by mass of the above hair removal composition, the content of component (C) is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, preferably 5.0% by mass or less, more preferably 4.0% by mass or less. When the content of component (C) is equal to or more than the above lower limit, the emulsion stability in a high temperature environment can be further improved. When the content of component (C) is equal to or less than the above upper limit, the viscosity of the hair removal composition immediately after production can be further improved.

(Component (D))
Component (D) is a polyoxyethylene alkyl ether having an HLB value of less than 12.0. By using component (D) in combination with component (B) and component (C), the effects of the present invention can be achieved. Component (D) may be used alone or in combination of two or more.

The HLB value of component (D) is less than 12.0. The HLB value of component (D) is preferably 11.0 or less, more preferably 10.0 or less.

Examples of component (D) include polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene myristyl ether, polyoxyethylene octyldodecyl ether, and polyoxyethylene behenyl ether.

From the viewpoint of exerting the effects of the present invention more effectively, the average number of moles of ethylene oxide (EO) added in component (D) (average number of moles of EO added in the polyoxyethylene portion) is preferably 1 or more, preferably 10 or less, and more preferably 8 or less.

In this specification, the number of carbon atoms in the alkyl group of component (D) is 6 or more. From the viewpoint of more effectively exerting the effects of the present invention, the number of carbon atoms in the alkyl group of component (D) is preferably 12 or more, more preferably 14 or more, and preferably 22 or less.

In 100% by mass of the above hair removal composition, the content of component (D) is preferably 1.0% by mass or more, more preferably 1.5% by mass or more, preferably 6.0% by mass or less, more preferably 5.0% by mass or less. When the content of component (D) is equal to or more than the above lower limit, the viscosity of the hair removal composition immediately after production can be made even better. When the content of component (D) is equal to or less than the above upper limit, the emulsion stability in a high-temperature environment can be further improved.

(Other ingredients)
The above hair remover composition may contain other components in addition to the above-mentioned components (A) to (D). Examples of the other components include an oily component, a hair removal promoting component, a nonionic surfactant different from both components (C) and (D), an anionic surfactant different from component (B), an amphoteric surfactant, a polyhydric alcohol, a lower alcohol, a silicone oil, a thickener, an alkali agent, a cooling agent, a preservative, an antioxidant, a metal sequestering agent, a colorant, and a fragrance. Only one type of each of the above other components may be used, or two or more types may be used in combination.

<Oily ingredients>
The hair removal composition preferably contains an oily component. When the hair removal composition contains an oily component, the viscosity of the hair removal composition immediately after production can be made even better.

The above-mentioned oily components include higher alcohols, hydrocarbon oils, ester oils, and fats and oils.

The higher alcohols include alcohols having 16 to 22 carbon atoms. Examples of the alcohols having 16 to 22 carbon atoms include cetyl alcohol, stearyl alcohol, isostearyl alcohol, 2-octyldodecanol, oleyl alcohol, and behenyl alcohol.

The above-mentioned hydrocarbon oils include α-olefin oligomers, light isoparaffin, light liquid isoparaffin, squalane, synthetic squalane, vegetable squalane, liquid isoparaffin, and liquid paraffin.

Examples of the ester oils include capric acid esters such as glyceryl caprate, caprylic acid esters such as glyceryl caprylate, cetyl 2-ethylhexanoate, and isononyl isononanoate.

Examples of the above-mentioned oils and fats include olive oil, rice bran oil, castor oil, coconut oil, camellia oil, macadamia nut oil, sunflower oil, grape seed oil, and avocado oil.

From the viewpoint of improving the viscosity of the hair removal composition immediately after production, the hair removal composition preferably contains an oil component (at least one oil component) selected from the group consisting of higher alcohols, hydrocarbon oils, ester oils, and oils and fats, and more preferably contains higher alcohols and/or hydrocarbon oils.

In 100% by mass of the above hair removal composition, the content of the above higher alcohol is preferably 2.0% by mass or more, more preferably 4.0% by mass or more, preferably 15.0% by mass or less, more preferably 10.0% by mass or less. When the content of the above higher alcohol is equal to or more than the above lower limit and equal to or less than the above upper limit, the viscosity of the hair removal composition immediately after production can be further improved.

In 100% by mass of the hair removal composition, the content of the hydrocarbon oil is preferably 1.0% by mass or more, more preferably 2.0% by mass or more, preferably 10.0% by mass or less, more preferably 5.0% by mass or less. When the content of the hydrocarbon oil is equal to or more than the lower limit and equal to or less than the upper limit, the viscosity of the hair removal composition immediately after production can be further improved.

In 100% by mass of the above hair removal composition, the content of the oily component selected from the group consisting of higher alcohols, hydrocarbon oils, ester oils, and fats and oils is preferably 3.0% by mass or more, more preferably 6.0% by mass or more, preferably 30.0% by mass or less, more preferably 20.0% by mass or less. When the content of the oily component is equal to or more than the above lower limit and equal to or less than the above upper limit, the viscosity of the hair removal composition immediately after production can be made even better.

<Hair removal promoting ingredients>
The hair removal promoting component includes a compound represented by the following formula (1).

In this specification, the above "compound represented by formula (1)" may be referred to as "hair removal promoting component (X)." By using hair removal promoting component (X), the hair removal power of component (A) can be increased.

In the above formula (1), R represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and n represents an integer of 2 to 5.

The alkyl group having 1 to 5 carbon atoms may be a straight-chain alkyl group or an alkyl group having a branched structure.

In the above formula (1), R is preferably an alkyl group having 1 or 2 carbon atoms. That is, in the above formula (1), R is preferably a methyl group or an ethyl group. In this case, the hair removal power can be further improved.

In the above formula (1), n is preferably 2 or 3, and more preferably 2. In this case, the hair removal promoting effect is more effectively exerted, and the hair removal power is more effectively enhanced.

In 100% by mass of the above hair removal composition, the content of the hair removal promoting component (X) is preferably 0.02% by mass or more, more preferably 0.1% by mass or more, and preferably 10.0% by mass or less. When the content of the hair removal promoting component (X) is equal to or more than the above lower limit, the hair removal promoting effect is more effectively exerted, and the hair removal power is more effectively enhanced. When the content of the hair removal promoting component (X) is equal to or less than the above upper limit, the hair removal power can be enhanced and skin irritation can be reduced.

<Nonionic surfactant different from both component (C) and component (D)>
The nonionic surfactant may, for example, be polyoxyethylene hydrogenated castor oil.

Examples of the polyoxyethylene hydrogenated castor oil include polyoxyethylene hydrogenated castor oil having an average number of moles of ethylene oxide (EO) added (average number of moles of EO added in the polyoxyethylene portion) of 30 or more and 80 or less.

<Anionic surfactant different from component (B)>
Examples of the anionic surfactant include alkyl sulfates such as sodium lauryl sulfate, triethanolamine lauryl sulfate, sodium myristyl sulfate, sodium stearyl sulfate, sodium oleyl sulfate, and sodium cetyl sulfate; polyoxyethylene alkyl ether sulfates such as sodium polyoxyethylene lauryl ether sulfate and sodium polyoxyethylene myristyl ether sulfate; α-olefin sulfonates such as sodium tetradecene sulfonate; N-acyl esters such as sodium myristoyl methyl taurate, sodium palmitoyl methyl taurate, sodium stearoyl methyl taurate, sodium oleoyl methyl taurate, and sodium coconut oil fatty acid methyl taurate. Methyl taurine salts; alkyl sulfosuccinate salts such as dioctyl sodium sulfosuccinate and disodium lauryl sulfosuccinate; alkyl polyoxyethylene sulfosuccinate salts such as polyoxyethylene lauryl disodium sulfosuccinate; monoalkyl phosphate salts such as sodium lauryl phosphate, sodium cetyl phosphate, and diethanolamine cetyl phosphate; polyoxyethylene lauryl ether sodium phosphate, sodium polyoxyethylene cetyl ether sodium phosphate, sodium polyoxyethylene oleyl ether phosphate, sodium polyoxyethylene alkylphenyl ether phosphate, and triethanolamine polyoxyethylene alkylphenyl ether phosphate. oxyethylene alkyl ether phosphate salts; N-acyl sarcosine salts such as potassium lauroyl sarcosine, triethanolamine lauroyl sarcosine, sodium myristoyl sarcosine, and sodium coconut oil fatty acid sarcosine; N-acyl-N-methyl-β-alanine salts such as sodium lauroyl methyl alanine, triethanolamine lauroyl methyl alanine, sodium myristoyl methyl alanine, and sodium coconut oil fatty acid methyl alanine; sodium lauroyl glutamate, triethanolamine lauroyl glutamate, sodium myristoyl glutamate, potassium stearoyl glutamate, disodium stearoyl glutamate, and coconut oil fatty acid acyl glutamic acid N-acylglutamates such as sodium and coconut oil fatty acid acylglutamate triethanolamine; N-acylglycine salts such as coconut oil fatty acid acylglycine potassium and coconut oil fatty acid acylglycine sodium; alkyl ether glycol acetates such as sodium lauryl glycol acetate (sodium dodecane-1,2-diol acetate), potassium lauryl glycol acetate, sodium myristyl glycol acetate, potassium myristyl glycol acetate, sodium palmityl glycol acetate, potassium palmityl glycol acetate, sodium stearyl glycol acetate, potassium stearyl glycol acetate, sodium behenyl glycol acetate, and potassium behenyl glycol acetate.

<Amphoteric surfactant>
Examples of the amphoteric surfactant include alkylamidobetaine-type amphoteric surfactants such as lauric acid amidopropyl betaine and coconut oil fatty acid amidopropyl betaine; glycine-type amphoteric surfactants such as alkylglycine salts, carboxymethylglycine salts, and N-acylaminoethyl-N-2-hydroxyethylglycine salts; aminopropionic acid-type amphoteric surfactants such as alkylaminopropionates and alkyliminodipropionates; alkyldimethylaminoacetic acid betaines, alkylamidopropyldimethylaminoacetic acid betaines, and alkyldihydroxyethyl aminoacetic acid betaine type amphoteric surfactants such as alkylaminoacetic acid betaine; sulfobetaine type amphoteric surfactants such as alkylhydroxysulfobetaine; imidazolinium type amphoteric surfactants such as alkylcarboxymethylhydroxyethylimidazolinium betaine; N-alkyl-N,N-dimethylammonium-N-propyl sulfonate; N-alkyl-N,N-dimethylammonium-N-(2-hydroxypropyl) sulfonate; and N-fatty acid amidopropyl-N,N-dimethylammonium-N-(2-hydroxypropyl) sulfonate.

<Polyhydric alcohol>
Examples of the polyhydric alcohol include ethylene glycol, propylene glycol, dipropylene glycol, polyethylene glycol, 1,3-butylene glycol, glycerin, concentrated glycerin, diglycerin, triglycerin, glucose, maltose, maltitol, sucrose, mannitol, sorbitol, 1,2-pentanediol, 1,2-hexanediol, and 1,2-octanediol.

<Lower alcohol>
The lower alcohol includes ethanol and the like.

<Silicone oil>
Examples of the silicone oil include methylpolysiloxane, highly polymerized methylpolysiloxane, methylphenylpolysiloxane, dimethiconol, methylhydrogenpolysiloxane, alcohol-modified silicone, alkyl-modified silicone, and amino-modified silicone.

<Thickener>
The thickening agent includes xanthan gum, carboxyvinyl polymer, hydroxymethylcellulose, hydroxypropylmethylcellulose, etc. The carboxyvinyl polymer may be an alkyl-modified carboxyvinyl polymer.

<Alkaline agent>
The hair removal composition preferably contains an alkaline agent.

Examples of the alkaline agent include sodium hydroxide, potassium hydroxide, calcium hydroxide, ammonia, ammonium bicarbonate, ammonium carbonate, sodium bicarbonate, sodium carbonate, isopropanolamine, monoethanolamine, diethanolamine, triethanolamine, and 2-amino-2-methyl-1-propanol.

From the viewpoint of ease of adjusting the pH to the required level for the hair removal composition, it is preferable that the alkaline agent is an alkaline agent (at least one alkaline agent) selected from the group consisting of sodium hydroxide, potassium hydroxide, and calcium hydroxide.

The content of the alkaline agent in 100% by mass of the above hair removal composition is preferably 0.7% by mass or more, more preferably 0.8% by mass or more, and preferably 10.0% by mass or less. When the content of the alkaline agent is equal to or more than the above lower limit and equal to or less than the above upper limit, it becomes easier to adjust the pH of the hair removal composition to within a suitable range, and the hair removal power can be further enhanced.

<Refreshing agent>
The cooling agents include 1-menthol, 1,8-cineole, camphor, and the like.

<Preservatives>
Examples of the preservatives include methylparaben, ethylparaben, propylparaben, isopropylparaben, butylparaben, isobutylparaben, and phenoxyethanol.

<Water>
The hair removal composition preferably contains water. The water is preferably purified water.

The water content in the hair removal composition can be adjusted as appropriate depending on the content of other ingredients. In 100% by mass of the hair removal composition, the water content is preferably 60.0% by mass or more, more preferably 65.0% by mass or more, preferably 90.0% by mass or less, more preferably 85.0% by mass or less.

(Other details of the hair removal composition)
The properties of the above hair remover composition are not particularly limited. The properties of the above hair remover composition may be milky, creamy, or paste-like. From the viewpoint of more effectively exerting the effects of the present invention, the properties of the above hair remover composition are preferably milky or creamy, and more preferably creamy. The above hair remover composition is preferably a milky or creamy hair remover composition, and more preferably a creamy hair remover composition.

The pH of the hair removal composition is preferably 11.0 or more, more preferably 11.5 or more, even more preferably 12 or more, and preferably 13.5 or less, more preferably 13.0 or less. If the pH is equal to or higher than the lower limit, the hair removal effect can be further increased, and if the pH is equal to or lower than the upper limit, skin irritation can be further suppressed.

The viscosity of the above hair removal composition at 35°C immediately after production is preferably 1000 mPa·s or more, more preferably 3000 mPa·s or more, even more preferably 5000 mPa·s or more, preferably 50,000 mPa·s or less, more preferably 40,000 mPa·s or less, even more preferably 30,000 mPa·s or less.

The viscosity is measured using a viscometer with a No. 4 rotor at a rotation speed of 12 rpm or 6 rpm for a rotation time of 1 minute. The viscometer may be a TV-25 model viscometer manufactured by Toki Sangyo Co., Ltd.

The method for producing the above hair removal composition can be a method for producing a known hair removal composition. Examples of the method for producing the above hair removal composition include a method in which each component is stirred and homogenized using a paddle mixer or the like.

The hair removal composition is not particularly limited, but may be used, for example, in a form contained in a container. When the hair removal composition is in the form of a milky lotion or cream, the container is preferably a tube container.

The present invention will be specifically described below with reference to examples and comparative examples. The present invention is not limited to the following examples. Note that the following Examples 4 to 6 are reference examples.

The following ingredients were used in the examples and comparative examples.

(Component (A))
Calcium thioglycolate (thioglycolic acid structure conversion rate: 50.0%)
Thioglycolic acid

(Component (B))
Polyoxyethylene cetyl ether phosphate (20E.O.), average number of moles of ethylene oxide added: 20
Polyoxyethylene cetyl ether phosphate (10E.O.), average number of moles of ethylene oxide added: 10
Polyoxyethylene stearyl ether phosphate (10E.O.), average number of moles of ethylene oxide added: 10

(Component (C))
Polyoxyethylene cetyl ether (20 E.O.), average number of moles of ethylene oxide added: 20, HLB value (measured by actual method): 17.0
Polyoxyethylene cetyl ether (40E.O.), average number of moles of ethylene oxide added: 40, HLB value (measured by actual method): 20.0
Polyoxyethylene stearyl ether (21E.O.), average number of moles of ethylene oxide added: 21, HLB value (measured by actual method): 18.0

(Component (D))
Polyoxyethylene stearyl ether (5E.O.), average number of moles of ethylene oxide added: 5, HLB value (measured): 9.5
Polyoxyethylene stearyl ether (2E.O.), average number of moles of ethylene oxide added: 2, HLB value (actual measurement method): 8.0

(Other ingredients)
Calcium hydroxide Sodium hydroxide Liquid paraffin Cetanol Cetostearyl alcohol Stearyl alcohol Diethylene glycol monoethyl ether (In the above formula (1), R: ethyl group, n: 2)
purified water

(Examples 1 to 12 and Comparative Examples 1 to 7)
Hair removal compositions were prepared by blending the ingredients (unit: mass %) shown in Tables 1 to 3 below. The blend amounts in the tables are shown as pure amounts.

(evaluation)
The obtained hair removal composition was evaluated as follows. The evaluation of Test Examples 2 to 4 was carried out by a panel of three experts, who discussed and decided the evaluation results.

(Test Example 1: pH)
The pH of the resulting hair remover composition was measured using a pH meter ("pH meter F-74" manufactured by Horiba, Ltd.).

(Test Example 2: Viscosity of hair removal composition immediately after production)
The depilatory composition immediately after production was visually observed. The temperature of the depilatory composition at the time of observation was 35° C. The viscosity of the depilatory composition immediately after production was evaluated according to the following criteria.

<Evaluation criteria for viscosity of hair removal composition immediately after production>
A: Creamy in nature and excellent in viscosity (viscosity at 35°C is about 5000 to about 30000 mPa·s)
B1: Slightly hard, but creamy in nature, with good viscosity (viscosity at 35°C is about 30,000 to about 50,000 mPa·s)
B2: Although the fluidity is somewhat high, the property is creamy and the viscosity is good (viscosity at 35°C is about 1000 to about 5000 mPa·s)
C: The property is not creamy and the viscosity is poor (viscosity at 35°C is less than about 1000 mPa·s)

(Test Example 3: Viscosity in a high temperature environment (observation after storage at 50°C for 1 day))
After the evaluation of Test Example 2, the hair remover composition was stored at room temperature (25° C.) for one day, and further stored at 50° C. for one day. The condition of the hair remover composition after storage at 50° C. for one day was visually confirmed.

<Evaluation criteria for viscosity under high temperature environment (observation after storage at 50°C for 1 day)>
A: The product is creamy in nature and has excellent viscosity. B: The product has a slightly high fluidity but is creamy in nature and has good viscosity. C: The product is not creamy in nature and has poor viscosity (excessively low viscosity).

(Test Example 4: Emulsion stability in a high temperature environment (observation after storage at 50° C. for 14 days))
After the evaluation of Test Example 3 was performed, the hair removal composition was stored for an additional 13 days at 50° C. The condition of the hair removal composition after storage was visually confirmed.

<Evaluation criteria for emulsion stability under high temperature environment (observation after storage at 50°C for 14 days)>
A: There is no or only slight change in properties before and after storage for 14 days (good emulsion stability)
B: A slight separation of the aqueous layer was observed on the surface of the hair removal composition (slightly good emulsion stability)
C: The hair removal composition is separated into two layers, an aqueous layer and an oil layer (poor emulsion stability)

The compositions and results are shown in Tables 1 to 3 below.

Claims (3)

The composition includes the following component A, the following component B, the following component C, and the following component D,
A hair removal composition, wherein a mass ratio of the content of said component C to the content of said component D is 0.4 or more and 0.8 or less.
Component A: thioglycolic acid and/or a salt thereof Component B: polyoxyethylene alkyl ether phosphate Component C: polyoxyethylene alkyl ether having an HLB value of 12.0 or more Component D: polyoxyethylene alkyl ether having an HLB value of less than 12.0 The hair removal composition according to claim 1 , wherein the HLB value of said component C is 16.0 or more. The hair removal composition according to claim 1 or 2 , which has a pH of 12 or more.