JP7839088B2 - Cleansing composition - Google Patents

Description

This invention relates to a detergent composition.

Cleansing agents used for facial cleansing generally contain high-grade fatty acid soaps due to their cleansing power and foaming properties. Furthermore, especially in facial cleansers, the combination of surfactants, humectants, and other additives is being considered to improve not only cleansing power but also user experience and moisturizing properties.

For example, Patent Document 1 reports a detergent containing (A) one or more selected from higher fatty acid salts, (B) a betaine-based amphoteric surfactant, (C) polyethylene glycol with an average degree of polymerization of 200 to 1540, (D) glyceryl monostearate with an HLB of 4 or less (excluding the component corresponding to (E)), and (E) a self-emulsifying glyceryl monostearate containing a fatty acid salt.

Japanese Patent Publication No. 2012-214391

The object of the present invention is to provide a novel detergent composition that is well soluble in water and provides good moisturizing properties after washing.

The present invention, which achieves the above objectives, is as follows:

<Aspect 1>
Water and,
Higher fatty acids and/or salts thereof,
A polymer having the structure represented by the following formula (1) is included,
In formula (1) above, ^R1 , ^R2 , and ^R3 are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, A is an alkylene group having 2 to 4 carbon atoms, and m and n are each independently 1.0 to 50.
The number-average molecular weight of the polymer is 10,000 or less, and the IOB value of the polymer is 0.4 to 1.8.
Cleansing composition.
<Aspect 2>
In equation (1) above, A is expressed by the following equation (2):
In formula (2) above, ^R4 is an alkyl group having 1 or 2 carbon atoms.
The composition according to Embodiment 1.
<Aspect 3>
The composition according to embodiment 1 or 2, wherein the polymer is a random copolymer.
<Aspect 4>
A composition according to any one of embodiments 1 to 3, further comprising at least one polyhydric alcohol.
<Aspect 5>
The composition according to embodiment 4, wherein the ratio of the total content of the polyhydric alcohols to the content of the polymer (polyhydric alcohols:polymers) is 5:1 to 80:1.
<Aspect 6>
The composition according to any one of embodiments 1 to 5, wherein the content of a component having a polyethylene glycol skeleton is 0.01% by mass or less.
<Aspect 7>
The composition according to any one of embodiments 1 to 6, wherein the higher fatty acid is a fatty acid having 12 to 18 carbon atoms.
<Pattern 8>
A composition for skin cleansing, according to any one of embodiments 1 to 7.

According to the present invention, a novel detergent composition can be provided that has good water solubility and provides excellent moisturizing properties after washing.

The embodiments of the present invention will be described in detail below. However, the present invention is not limited to the embodiments described below, and can be implemented with various modifications within the scope of the invention's essence.

Cleansing composition
The detergent composition of the present invention (hereinafter also simply referred to as "the composition of the present invention") is
Water and,
Higher fatty acids and/or salts thereof,
A polymer having the structure represented by the following formula (1) is included,
In formula (1), ^R1 , ^R2 , and ^R3 are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, A is an alkylene group having 2 to 4 carbon atoms, and m and n are each independently 1.0 to 50.
The number-average molecular weight of the polymer is 10,000 or less, and the IOB value of the polymer is 0.4 to 1.8.
It is a cleaning agent composition.

The composition of the present invention has good water solubility and retains good moisture after washing. Furthermore, due to its good water solubility, the composition of the present invention also exhibits good foaming properties.

While not limited to theory, this is presumed to be due to the properties of the polymer of the present invention, namely the unique structure shown in formula (1) above, the specific range of number-average molecular weight (10,000 or less), and the specific range of IOB (Inorganic Organic Balance) values (0.4 to 1.8).

Furthermore, the polymer of the present invention, possessing a specific structure, is amphiphilic and tends to dissolve in the aqueous phase, but also has hydrophobic properties. Therefore, it is considered to have good affinity with higher fatty acids and/or their salts and other components (e.g., humectants and nonionic surfactants) and makeup components contained in the composition of the present invention, as well as good affinity with the skin.

Generally, compounds having a polyethylene glycol skeleton are used to improve the water solubility of detergent compositions. In contrast, the polymer of the present invention, in which A in formula (1) is represented by the following formula (2), does not have a polyethylene glycol skeleton, yet compositions of the present invention containing such a polymer exhibit excellent water solubility and moisturizing properties after washing.
( ^R4 is an alkyl group having 1 or 2 carbon atoms)

The propylene glycol and butylene glycol used as raw materials for the portion represented by formula (2) above are more readily available from natural sources compared to ethylene glycol, which is used as a raw material for the polyethylene glycol backbone. Therefore, it is preferable that the polymer of the present invention, which does not have a polyethylene glycol backbone, can improve the water solubility of the composition and the moistness after washing.

<water>
The composition of the present invention contains water.

While there are no specific limitations on the type of water used, water used in cosmetics, quasi-drugs, etc., can be used. For example, purified water, deionized water, tap water, etc., can be used.

In the composition of the present invention, the water content is not particularly limited and can be appropriately adjusted, for example, depending on the content of components other than water. More specifically, the water content may be, for example, 5.0% by mass or more, 10% by mass or more, 15% by mass or more, 20% by mass or more, 25% by mass or more, or 30% by mass or more, relative to the total composition, or 80% by mass or less, 70% by mass or less, 60% by mass or less, 50% by mass or less, 40% by mass or less, or 35% by mass or less.

<Higher fatty acids>
The composition of the present invention comprises higher fatty acids and/or salts thereof. That is, the composition of the present invention may contain higher fatty acids, may contain higher fatty acid salts, or may contain a mixture of higher fatty acids and higher fatty acid salts.

Higher fatty acids refer to chain-like monocarboxylic acids with six or more carbon atoms. In this invention, saturated, unsaturated, linear, or branched fatty acids can be used as higher fatty acids, but those with 12 to 18 carbon atoms are preferred. More specifically, the higher fatty acids that may be included in the composition of this invention may include, for example, one or a combination of two or more of the following: lauric acid, myristic acid, palmitic acid, stearic acid, palmitoleic acid, oleic acid, isomyristic acid, isopalmitic acid, and isostearic acid. Among these, from the viewpoint of improving the cleaning effect, it is preferable to use a combination of two or more of lauric acid, myristic acid, palmitic acid, and stearic acid, and more preferably a combination of these four.

In this invention, since the higher fatty acid salt is incorporated for the purpose of constituting a fatty acid soap, the type of higher fatty acid salt is not particularly limited. More specifically, the salt of the higher fatty acid may be, for example, a metal salt such as sodium or potassium salt, an ammonium salt, a monoethanolamine salt, a diethanolamine salt, a triethanolamine salt, an alkanolamine such as 2-amino-2-methylpropanol or 2-amino-2-methylpropanediol, or a basic amino acid salt such as lysine or arginine. Of these, potassium salt is preferred from the viewpoint of improving foaming properties.

In this invention, higher fatty acid salts can be obtained, for example, by neutralizing higher fatty acids with a neutralizing agent during the preparation of the composition. Generally, complete neutralization is not achieved, and the product includes unreacted higher fatty acids. In this invention, the neutralization rate of higher fatty acids is not particularly limited, but is preferably 60-90 mol%, more preferably 70-85 mol%. Therefore, the detergent according to this invention preferably contains 60-90 mol%, more preferably 70-85 mol%, of higher fatty acid salts, and preferably 10-40 mol%, more preferably 15-30 mol%, of higher fatty acids. The content of the neutralizing agent is not particularly limited and can be adjusted as appropriate to achieve the above neutralization rate.

Furthermore, the neutralizing agent used to neutralize higher fatty acids is not particularly limited and is not limited to any neutralizing agent commonly used as an ingredient in higher fatty acid soaps. More specifically, examples of neutralizing agents include hydroxides of alkali metal salts such as potassium hydroxide and sodium hydroxide, hydroxides of alkaline earth metals such as magnesium hydroxide and calcium hydroxide, alkanolamines such as 2-amino-2-methyl-1-propanol, monoethanolamine, diethanolamine, and triethanolamine, basic amino acids such as L-arginine, lysine, and ornithine, aqueous ammonia, ammonium hydroxide, and sodium bicarbonate. Among these, from the viewpoint of improving solubility in water and cleaning effect, one or more selected from sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, aqueous ammonia, monoethanolamine, diethanolamine, and triethanolamine are preferred, one or more selected from sodium hydroxide, potassium hydroxide, aqueous ammonia, monoethanolamine, diethanolamine, and triethanolamine are more preferred, and one or two selected from sodium hydroxide and potassium hydroxide are preferred.

In the composition of the present invention, the content of higher fatty acids and/or salts thereof is not particularly limited. For example, it may be 5.0% by mass or more, 10% by mass or more, 15% by mass or more, 20% by mass or more, or 25% by mass or more, relative to the whole composition. It may also be 60% by mass or less, 55% by mass or less, 50% by mass or less, 45% by mass or less, 40% by mass or less, 35% by mass or less, or 30% by mass or less. In the present invention, "content of higher fatty acids and/or salts thereof" means "content of higher fatty acids" when higher fatty acids are included alone, "content of higher fatty acid salts" when higher fatty acid salts are included alone, and "total content of higher fatty acids and higher fatty acid salts" when both higher fatty acids and higher fatty acid salts are included. Furthermore, when preparing a composition by separately adding the fatty acid that forms the basis of the fatty acid portion of the higher fatty acid salt and a neutralizing agent, if the reaction is carried out in equivalent amounts, the amount of the obtained higher fatty acid salt is calculated as the "content of higher fatty acids and/or their salts." If there is a remaining amount of the higher fatty acid that forms the basis of the fatty acid portion of the higher fatty acid salt, the sum of that remaining amount and the amount of the obtained higher fatty acid salt is calculated as the "content of higher fatty acids and/or their salts."

<The polymer of the present invention>
The polymer of the present invention has a structure represented by the following formula (1):

In formula (1), ^R1 , ^R2 , and ^R3 are each independently a hydrogen atom or a C1-C4 alkyl group. Examples of C1-C4 alkyl groups in the present invention include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, and tert-butyl groups. Furthermore, these alkyl groups may have substituents as long as they do not impair the effects of the present invention. Substituents are not particularly limited and include, for example, halogen groups.

According to one embodiment of the present invention, in formula (1), ^R1 , ^R2 , and ^R3 may each be independently a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, or a tert-butyl group.

According to one embodiment of the present invention, in formula (1), ^R1 is preferably a hydrogen atom, a methyl group, or an ethyl group. Furthermore, when m is 2 or more, that is, when there are multiple ^R1s , each ^R1 may be the same or different, and it is particularly preferable that at least a portion of ^R1 is a methyl group. When at least a portion of ^R1 is a methyl group, it is preferable, for example, from the viewpoint of improving the feel of the composition of the present invention.

According to one embodiment of the present invention, in formula (1), ^R1 may be a mixture of hydrogen atoms and an alkyl group having 1 to 4 carbon atoms. That is, part of ^R1 may be hydrogen atoms and the other part may be an alkyl group having 1 to 4 carbon atoms. Preferably, part of ^R1 is hydrogen atoms and the other part is a methyl group.

According to one embodiment of the present invention, in formula (1), ^R2 is preferably a hydrogen atom, a methyl group, or an ethyl group, and is more preferably a methyl group.

According to one embodiment of the present invention, in formula (1), ^R2 may be a mixture of hydrogen atoms and an alkyl group having 1 to 4 carbon atoms. That is, part of ^R2 may be hydrogen atoms and the other part may be an alkyl group having 1 to 4 carbon atoms. Preferably, part of ^R2 is hydrogen atoms and the other part is a methyl group.

According to one embodiment of the present invention, in formula (1), ^R3 is preferably a hydrogen atom, a methyl group, or an ethyl group, and is more preferably a methyl group.

According to one embodiment of the present invention, in formula (1), it is preferable that at least one of ^R2 and ^R3 is a methyl group.

In formula (1), A is an alkylene group having 2 to 4 carbon atoms. More specifically, A may be, for example, an ethylene group, a propylene group, a butylene group, an isobutylene group, etc., but is not limited to these. In particular, A is preferably represented by the following formula (2):

In formula (2), ^R4 is an alkyl group having 1 or 2 carbon atoms. More specifically, ^R4 may be a methyl group or an ethyl group.

In equation (1), m and n represent the average number of moles added to each constituent unit. m and n are independently between 1.0 and 50, and more specifically, they may be 1.0 or greater, 1.5 or greater, 2.0 or greater, 3.0 or greater, 4.0 or greater, 5.0 or greater, 6.0 or greater, 7.0 or greater, 8.0 or greater, 9.0 or greater, or 10 or greater. They may also be 50 or less, 45 or less, 40 or less, 35 or less, 34 or less, 32 or less, 30 or less, 28 or less, 26 or less, 25 or less, 24 or less, 22 or less, 20 or less, 18 or less, 16 or less, 15 or less, 14 or less, 12 or less, 10 or less, or 5.0 or less.

Furthermore, in formula (1), m is preferably between 1.0 and 14, and more preferably between 2.0 and 5.0. Also, in formula (1), n is preferably between 2.0 and 34, and more preferably between 6.0 and 12.

According to one embodiment of the present invention, in formula (1), m+n may be 4.0 or greater, 4.5 or greater, 5.0 or greater, 6.0 or greater, 7.0 or greater, 8.0 or greater, 9.0 or greater, 10 or greater, 11 or greater, 12 or greater, 13 or greater, 14 or greater, or 15 or greater, and may also be 50 or less, 45 or less, 40 or less, 35 or less, 30 or less, 25 or less, 20 or less, 15 or less, or 12 or less.

According to one embodiment of the present invention, in equation (1), m:n may be 1:10 to 10:1.

The polymer of the present invention has a number-average molecular weight of 10,000 or less. More specifically, the number-average molecular weight of the polymer of the present invention may be, for example, 10,000 or less, 5,000 or less, 3,500 or less, 3,000 or less, 2,500 or less, 2,000 or less, 1,500 or less, 1,400 or less, 1,300 or less, 1,200 or less, 1,100 or less, 1,000 or less, 900 or less, 800 or less, 700 or less, or 600 or less, and may also be 130 or more, 150 or more, 200 or more, 250 or more, 300 or more, 350 or more, 400 or more, 450 or more, or 500 or more. Furthermore, the number-average molecular weight of the polymer of the present invention is preferably 300 or more and 3,500 or less, and more preferably 500 or more and 1,200 or less.

The IOB value of the polymer of the present invention is 0.4 to 1.8. More specifically, the IOB value of the polymer of the present invention may be, for example, 0.4 or higher, 0.5 or higher, 0.6 or higher, or 0.7 or higher, and may also be 1.8 or lower, 1.6 or lower, 1.4 or lower, or 1.2 or lower. Furthermore, it is preferable that the IOB value of the polymer of the present invention is 0.7 or higher and 1.2 or lower.

Here, IOB value is an abbreviation for Inorganic/Organic Balance, and it represents the ratio of inorganic value to organic value, serving as an indicator of the degree of polarity of an organic compound. Specifically, the IOB value is expressed as IOB value = inorganic value / organic value. For each of the "inorganic value" and "organic value," for example, one carbon atom in a molecule has an "organic value" of 20, and one hydroxyl group has an "inorganic value" of 100. The "inorganic value" and "organic value" are set according to various atoms or functional groups. The IOB value of an organic compound can be calculated by summing the "inorganic value" and "organic value" of all atoms and functional groups in the organic compound (see, for example, "Organic Concept Diagrams - Fundamentals and Applications" by Yoshio Koda, pp. 11-17, Sankyo Publishing, 1984). For the method of determining the IOB value, please refer to the method described in the examples.

The polymer of the present invention may be a block copolymer or a random copolymer, but a random copolymer is preferred.

The method for producing the polymer of the present invention is not particularly limited, and may, for example, be carried out by addition polymerization of epoxides corresponding to each constituent unit. Furthermore, the addition polymerization may be block polymerization or random polymerization, but random polymerization is preferred.

Furthermore, the polymer production method of the present invention may further include reacting the polymer obtained by the above addition polymerization with an alkyl halide. Through the reaction with the alkyl halide, the hydroxyl groups within the polymer molecule are sequestered by the alkyl group, thereby allowing the overall hydrophobicity of the polymer to be adjusted as desired. In the present invention, the sequestering rate of hydroxyl groups by the alkyl group within the polymer molecule may be, for example, 30% or more, 35% or more, 40% or more, 45% or more, 50% or more, or 55% or more, and may also be 60% or less, 59% or less, 58% or less, 57% or less, 56% or less, or 55% or less. The sequestering rate of hydroxyl groups by the alkyl group can be determined by the method described in the examples.

One of the key features of the polymer of this invention is its combination of high water solubility and high lipid solubility.

The solubility of the polymer of the present invention in water may be, for example, 10% by mass or more, 20% by mass or more, 30% by mass or more, 40% by mass or more, or 50% by mass or more.

Furthermore, the solubility of the polymer of the present invention can be indicated by, for example, its solubility in olive oil. The solubility of the polymer of the present invention in olive oil may be, for example, 0.01% by mass or more, 0.05% by mass or more, 0.10% by mass or more, 0.50% by mass or more, or 1.00% by mass or more. The upper limit of the solubility of the polymer of the present invention in olive oil is not particularly limited and may be, for example, 10% by mass or less.

In the composition of the present invention, the content of the polymer of the present invention is not particularly limited and may be, for example, 0.001% by mass or more, 0.005% by mass or more, 0.01% by mass or more, 0.05% by mass or more, 0.1% by mass or more, 0.5% by mass or more, 1.0% by mass or more, 2.0% by mass or more, 3.0% by mass or more, or 4.0% by mass or more. Alternatively, it may be 10.0% by mass or less, 9.0% by mass or less, 8.0% by mass or less, 7.0% by mass or less, 6.0% by mass or less, 5.0% by mass or less, 4.0% by mass or less, 3.0% by mass or less, 2.0% by mass or less, or 1.0% by mass or less.

<Other ingredients>
The composition of the present invention may further contain other components, as long as they do not impair the effects of the present invention. Other components are described below illustratively, but the present invention is not limited to these.

As mentioned above, generally, compounds having a polyethylene glycol skeleton are used to improve the water solubility of detergent compositions. In contrast, the polymer of the present invention, represented by formula (2) above, where A in formula (1) is, does not have a polyethylene glycol skeleton. Nevertheless, compositions containing such polymers of the present invention exhibit excellent water solubility and moisturizing properties after washing. The compositions of the present invention may substantially contain no components having a polyethylene glycol skeleton, or if they do, their content may be 0.01% by mass or less, 0.005% by mass or less, or 0.001% by mass or less.

(Polyhydric alcohol)
The composition of the present invention preferably further contains at least one polyhydric alcohol, because polyhydric alcohols can impart moisture after washing. Therefore, polyhydric alcohols can also be referred to as moisturizers, depending on the type.

A polyhydric alcohol is an alcohol having two or more hydroxyl groups in its molecule. In this invention, the polyhydric alcohol is not particularly limited and includes, for example, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, dipropylene glycol, glycerin, diglycerin, sorbitan, sorbitol, maltitol, glucose, and sucrose. Of these, from the viewpoint of further improving the effects of this invention, it is preferable that the polyhydric alcohol includes at least one selected from the group consisting of dipropylene glycol, glycerin, and sorbitol.

In the composition of the present invention, the content of polyhydric alcohols (or the total content in the case of two or more types of polyhydric alcohols) is not particularly limited. For example, it may be 5.0% by mass or more, 10% by mass or more, 15% by mass or more, 20% by mass or more, 25% by mass or more, or 30% by mass or more relative to the entire composition, or it may be 60% by mass or less, 55% by mass or less, 50% by mass or less, 45% by mass or less, 40% by mass or less, 35% by mass or less, or 30% by mass or less.

Furthermore, in the composition of the present invention, if a polyhydric alcohol is included, the ratio of the total content of the polyhydric alcohol to the content of the polymer of the present invention (polyhydric alcohol: polymer of the present invention) is not particularly limited and may be, for example, 5:1 to 80:1, or 5:1 to 70:1, 5:1 to 60:1, or 8:1 to 30:1.

(Surfactants)
The composition of the present invention preferably further contains a surfactant. The surfactant is not particularly limited, but for example, from the viewpoint of improving foam quality and foam retention, a nonionic surfactant is preferred, and from the viewpoint of improving foaming ability, an amphoteric surfactant is preferred. For this reason, the composition of the present invention preferably uses both a nonionic surfactant and an amphoteric surfactant in combination.

Nonionic surfactants are not particularly limited and include, for example, polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, and polyoxyethylene stearyl ether; polyoxyethylene polyoxypropylene alkyl ethers such as polyoxyethylene polyoxypropylene lauryl ether, polyoxyethylene polyoxypropylene cetyl ether, polyoxyethylene polyoxypropylene stearyl ether, and polyoxyethylene polyoxypropylene decyltetradecyl ether; polyoxyethylene alkylphenyl ethers such as polyoxyethylene octylphenyl ether and polyoxyethylene nonylphenyl ether; sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monostearate, and sorbitan monooleate; and polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monostearate, and polyoxyethylene sorbitan trioleate. Examples include oxyethylene sorbitan fatty acid esters; glycerin fatty acid esters such as glyceryl laurate, glyceryl myristate, glyceryl stearate, glyceryl isostearate, and glyceryl behenate; polyoxyethylene fatty acid glycers such as polyoxyethylene glyceryl monostearate, polyoxyethylene glyceryl monooleate, polyoxyethylene glyceryl triisostearate, polyoxyethylene (caprylic/capric acid) glyceryl, and polyoxyethylene glyceryl isostearate; polyglycerin fatty acid esters such as diglyceryl monostearate, decaglyceryl monooleate, polyglyceryl caprylate, and polyglyceryl laurate; polyoxyethylene fatty acid esters such as polyethylene glycol monolaurate and polyethylene glycol monostearate; polyoxyethylene castor oil; hydrogenated castor oil; polyoxyethylene hydrogenated castor oil; polyoxyethylene lanolin; and polyoxyethylene reduced lanolin.

In the composition of the present invention, the content of a nonionic surfactant is not particularly limited. For example, it may be 0.1% by mass or more, 0.5% by mass or more, 1.0% by mass or more, 1.5% by mass or more, 2.0% by mass or more, 2.5% by mass or more, 3.0% by mass or more, 3.5% by mass or more, or 4.0% by mass or more, relative to the total composition. Alternatively, it may be 10% by mass or less, 9.0% by mass or less, 8.0% by mass or less, 7.0% by mass or less, 6.0% by mass or less, 5.0% by mass or less, 4.0% by mass or less, 3.0% by mass or less, or 2.0% by mass or less.

The amphoteric surfactant is not particularly limited and includes, for example, glycine-type amphoteric surfactants, aminopropionic acid-type amphoteric surfactants, amidopropyl betaine-type amphoteric surfactants, aminoacetic acid betaine-type amphoteric surfactants, and sulfobetaine-type amphoteric surfactants. More specifically, examples of amphoteric surfactants include alkyldiaminoethylglycine hydrochloride, sodium lauryldiaminoethylglycine, lauryl betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolium betaine (also called "sodium cocoamphoacetate"), sodium laurylaminopropionate, laurylaminopropionate triethanolamine, sodium laurylaminodipropionate, coconut oil fatty acid acyl-N-carboxyethyl-N-hydroxyethylethylenediamine sodium, coconut oil fatty acid acyl-N-carboxyethoxyethyl-N-carboxyethylethylenedi Examples include disodium amine, coconut oil fatty acid amidopropyl betaine, palm oil fatty acid amidopropyl betaine, lauric acid amidopropyl betaine, ricinoleic acid amidopropyl betaine, lauryldimethylaminoacetic acid betaine, coconut oil alkyldimethylaminoacetic acid betaine, stearyldimethylaminoacetic acid betaine, stearyl dihydroxyethyl betaine, lauric acid amidopropyl acetate betaine, lauryl hydroxysulfobetaine, lauric acid amidopropyl hydroxysulfobetaine, myristate acid amidopropyl hydroxysulfobetaine, and coconut oil fatty acid amidopropyl hydroxysulfobetaine.

In the composition of the present invention, the content of the amphoteric surfactant, if present, is not particularly limited. For example, it may be 0.1% by mass or more, 0.5% by mass or more, 1.0% by mass or more, 1.5% by mass or more, 2.0% by mass or more, 2.5% by mass or more, 3.0% by mass or more, 3.5% by mass or more, or 4.0% by mass or more, relative to the total composition. Alternatively, it may be 10% by mass or less, 9.0% by mass or less, 8.0% by mass or less, 7.0% by mass or less, 6.0% by mass or less, 5.0% by mass or less, 4.0% by mass or less, 3.0% by mass or less, or 2.0% by mass or less.

In addition to the components described above, the composition of the present invention may optionally contain other components commonly added to skin cleansing agents, provided that these do not impair the effects of the present invention. Examples of such components include, but are not limited to, buffering agents (e.g., citric acid, sodium citrate, etc.), chelating agents (e.g., EDTA, etc.), dyes, and fragrances.

Method for producing the composition of the present invention
The method for producing the composition of the present invention is not particularly limited and can be carried out, for example, by mixing the essential components described above with other components that may be added as desired. Furthermore, when mixing, means such as heating or stirring may be used as needed.

Uses of the composition of the present invention
The composition of the present invention can be suitably used, for example, as a skin cleanser or a skin moisturizing cleanser. The composition of the present invention can be particularly suitably used as a facial cleanser. Furthermore, because the composition of the present invention has excellent foaming properties, it may be called, for example, a facial cleansing foam.

Furthermore, the product form of the composition of the present invention is not particularly limited and may be, for example, a paste, a foam, an emulsion, or a gel. Here, "paste" means exhibiting a paste-like (glue-like) state at room temperature (25°C).

The present invention will be further explained with reference to the following examples, but the present invention is not limited to these examples.

《Synthesis Examples 1 and 2》
The following synthesis examples 1 and 2 synthesized polymers having the structure represented by the following formula (3):
In formula (3), the terms in brackets [] represent random copolymers.

<Synthesis Example 1>
Synthesis Example 1: Polymer 1 with ^R1 = H, ^R2 = H, ^R3 = _CH3 , ^R4 = _CH3 , m = 2.0, and n = 6.0
Polymer 1 was obtained by synthesis using the method described below.

128 g of methanol and 6.4 g of potassium hydroxide as a catalyst were charged into an autoclave. After replacing the air in the autoclave with dry nitrogen, the catalyst was completely dissolved at 80°C while stirring. Next, a mixture of 592 g of glycidol and 1392 g of propylene oxide was added dropwise at 95°C over 20 hours using a dropping device, followed by stirring for 5 hours. The reaction composition was removed from the autoclave, neutralized with hydrochloric acid to pH 6-7, and treated under reduced pressure of -0.095 MPa (50 mmHg) at 100°C for 1 hour to remove any remaining water. Further filtration was performed to remove the salts formed after treatment, yielding 1,2000 g of the polymer from Synthesis Example 1.

Below, various physical properties were determined for the obtained polymer 1.

(number average molecular weight)
The number-average molecular weight of the obtained polymer 1 was calculated by gel permeation chromatography (GPC). The system used was a SHODEX® GPC101 GPC-dedicated system, with a SHODEX RI-71s differential refractometer, a SHODEX KF-G guard column, and three SHODEX KF804L columns mounted in sequence. The column temperature was 40°C, and tetrahydrofuran was flowed at a flow rate of 1 ml/min as the developing solvent. 0.1 ml of a 0.1 wt% tetrahydrofuran solution of the obtained reaction product was injected, and a chromatogram representing refractive index intensity and elution time was obtained using the BORWIN GPC calculation program. Using polyethylene glycol as the standard, the number-average molecular weight was determined from this chromatogram to be approximately 530.

(Weight average molecular weight)
The weight-average molecular weight of the obtained polymer 1 was determined by GPC calculation in the same manner as described above, and was approximately 859.

(Polydispersity)
Based on the number-average molecular weight and weight-average molecular weight obtained above, the polydispersity Mw/Mn of polymer 1 was 1.62.

(IOB value)
The IOB value of the obtained polymer 1 was determined to be 1.1, as follows.

More specifically, in polymer 1, the organic value was calculated using a carbon value of 20 and an iso branching value of -10. The inorganic value was calculated using a hydroxyl group value of 100 and an ether bond value of 20.
• Methanol moiety: (1 carbon atom, 1 hydroxyl group) x 1
Organic content value: 20
Inorganic value: 100
Glycidol moiety: (3 carbon atoms, 1 iso-branch, 1 hydroxyl group, 1 ether bond) x 2
Organic content value: (60 - 10) × 2 = 100
Inorganic value: (100 + 20) × 2 = 240
• Propylene oxide moiety: (3 carbon atoms, 1 iso-branch, 1 ether bond) x 6
Organic content value: (60 - 10) × 6 = 300
Inorganic value: 20 × 6 = 120
Based on the above, the total organic value is 420 and the total inorganic value is 460, resulting in an IOB value of 1.09.

(cloud point)
A 5 wt% aqueous solution was prepared from the obtained polymer 1, heated to 85°C, and then cooled. The temperature at which it became a clear solution was 74°C. Therefore, it was found that the cloud point of polymer 1 is 74°C.

(Hydroxyl value)
The hydroxyl value of the obtained polymer 1 was measured according to the measurement method of JIS K-1557-1 and was found to be 294.

(Solubility in water)
The solubility of the obtained polymer 1 in water was determined to be 50% by mass or more, using the same method as described later in the "compatibility evaluation" section.

(Solubility in olive oil)
The solubility of the obtained polymer 1 in olive oil was determined as follows: Polymer 1 was mixed with olive oil to a concentration of 1.0 wt%, and its appearance was checked. A uniform appearance was marked with "○". In this case, the solubility of polymer 1 in olive oil was 1.0 mass%.

The various physical properties of polymer 1 measured above are shown in Table 1 below.

<Synthesis Example 2>
Synthesis Example 2: Polymer 2 of ^R1 = H and _CH3 , ^R2 = H and _CH3 , ^R3 = _CH3 , ^R4 = _CH3 , m = 2.0, and n = 6.0
Polymer 2 was obtained by synthesis using the method described below.

128 g of methanol and 6.4 g of potassium hydroxide as a catalyst were charged into an autoclave. After replacing the air in the autoclave with dry nitrogen, the catalyst was completely dissolved at 80°C while stirring. Next, a mixture of 592 g of glycidol and 1392 g of propylene oxide was added dropwise at 95°C over 20 hours using a dropping device, and then stirred for 2 hours. Next, 244 g of potassium hydroxide was charged, the system was replaced with dry nitrogen, and then 200 g of methyl chloride was injected under pressure at a temperature of 80-130°C and reacted for 5 hours. After that, the reaction composition was removed from the autoclave, neutralized with hydrochloric acid to pH 6-7, and treated at a reduced pressure of -0.095 MPa (50 mmHg) and 100°C for 1 hour to remove the contained water. Further filtration was performed to remove the salts formed after treatment, and 2,1820 g of polymer was obtained. A sample was taken before reacting with methyl chloride, and the hydroxyl value of the purified sample was 125. This indicated that the ratio of methyl groups to hydrogen atoms ( _CH3 /H) in ^R2 and ^R3 was 0.57. In other words, the hydroxyl group chelating rate of polymer 2 was 57%.

Similar to the case of polymer 1 described above, various physical properties were determined for the obtained polymer 2, and the results are shown in Table 1 below.

Examples 1-8, Comparative Examples 1 and 2, and Reference Example 1
A paste-like cleansing composition was prepared using the formulations shown in Table 2 below. Unless otherwise specified, the values in Table 2 represent the amount of each ingredient, and the unit is mass percent.

Furthermore, the usability (water solubility during washing and moisturizing effect after washing) of each obtained composition was comprehensively evaluated by five expert sensory evaluation panel members when they washed their faces, using the composition of Comparative Example 1 as a baseline. The evaluation criteria are as follows, and the evaluation results are shown in Table 2.

<Dissolving in water during washing>
・Reference composition: Comparative example 1
• Evaluation results:
"A": Clearly better solubility in water compared to Comparative Example 1;
"B": Slightly better solubility in water compared to Comparative Example 1;
"C": Approximately the same as Comparative Example 1;
"D": Slightly less soluble in water compared to Comparative Example 1;
"E": Its solubility in water is clearly worse compared to Comparative Example 1.

Furthermore, solubility in water was determined by the ease with which the composition dissolved when 1 g of the composition sample was mixed with 10 g of water.

<Moisturizing effect after washing>
・Reference composition: Comparative example 1
• Evaluation results:
"A": Compared to Comparative Example 1, the skin feels noticeably more moisturized;
"B": Compared to Comparative Example 1, the skin feels slightly more moisturized;
"C": Approximately the same as Comparative Example 1;
"D": Compared to Comparative Example 1, the skin feels slightly less moisturized;
"E": Compared to Comparative Example 1, the skin feels noticeably less moisturized.

As is clear from the results in Table 2, the detergent compositions of Examples 1 to 8 were all found to be significantly improved compared to Comparative Example 1 in both water solubility and post-wash moisturizing properties.

On the other hand, in Comparative Example 2, although the type of amphoteric surfactant was changed, no improvement was observed in either water solubility or post-wash moisturizing effect compared to Comparative Example 1.

Furthermore, while the detergent composition of Reference Example 1 shows clear improvements in both water solubility and post-wash moisturizing properties compared to Comparative Example 1, this Reference Example detergent composition contains a component having a polyethylene glycol skeleton.

In contrast, the cleaning compositions of Examples 1 to 8 were found to be excellent in both water solubility and post-wash moisturizing properties, even though none of them contained components with a polyethylene glycol skeleton, such as polyethylene glycol.

Claims (8)

Water and,
Higher fatty acids and/or salts thereof,
A polymer having the structure represented by the following formula (1) is included,
In formula (1) above, ^R1 , ^R2 , and ^R3 are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, A is an alkylene group having 2 to 4 carbon atoms, and m and n are each independently 1.0 to 50.
The number-average molecular weight of the polymer is 10,000 or less, and the IOB value of the polymer is 0.4 to 1.8.
Cleansing composition. In equation (1) above, A is expressed by the following equation (2):
In formula (2) above, ^R4 is an alkyl group having 1 or 2 carbon atoms.
The composition according to claim 1. The composition according to claim 1 or 2, wherein the polymer is a random copolymer. The composition according to claim 1 or 2, further comprising at least one polyhydric alcohol. The composition according to claim 4, wherein the ratio of the total content of the polyhydric alcohols to the content of the polymer (polyhydric alcohols:polymers) is 5:1 to 80:1. The composition according to claim 1 or 2, wherein the content of a component having a polyethylene glycol skeleton is 0.01% by mass or less. The composition according to claim 1 or 2, wherein the higher fatty acid is a fatty acid having 12 to 18 carbon atoms. A composition according to claim 1 or 2, for use in skin cleansing.