JP7735124B2 - Oil-in-water emulsion composition - Google Patents

Description

This disclosure relates to an oil-in-water emulsion composition.

Oil-in-water emulsion compositions are used in the fields of cosmetics, quasi-drugs, etc.

Patent Document 1 describes an oil-in-water emulsion composition characterized by the incorporation of (A): 0.01 to 2.0% by mass of a water-soluble gelling agent, (B): 0.01 to 1.0% by mass of a water-soluble thickener, (C): 0.01 to 2.0% by mass of a gemini type anionic surfactant, (D): a water-soluble whitening agent, (E): an electrolyte other than (D), and (F): an oil.

Patent Document 2 describes a composition for external use on the skin that contains 1) a melanin production inhibitor consisting of D-pantothenyl alcohol, and 2) one or more substances selected from specific plant extracts, compounds, and other substances.

Patent Document 3 describes an oil-in-water cosmetic containing (a) (sodium acrylate/sodium acryloyldimethyltaurate) copolymer, (b) gellan gum, (c) an electrolyte, and (d) an oil.

Japanese Patent Application Laid-Open No. 2019-142825 Japanese Patent Application Laid-Open No. 2019-019077 JP 2016-190835 A

Oil-in-water emulsion compositions used in cosmetics and other applications are often required to have a good feel when used, such as a fresh, moisturizing sensation. Furthermore, considering the storage of products to which an oil-in-water emulsion composition is applied, emulsion stability is also required of the oil-in-water emulsion composition.

The problem that one embodiment of the present disclosure aims to solve is to provide an oil-in-water emulsion composition that has a fresh, moisturizing feel and excellent emulsion stability.

The present disclosure includes the following embodiments.
[1] Betaine,
(Sodium acrylate/sodium acryloyldimethyltaurate) copolymer;
At least one compound I selected from the group consisting of gellan gum and polyacrylamide;
at least one compound II selected from the group consisting of (PEG-240/decyltetradeceth-20/HDI) copolymer, bisstearyl PEG/PPG-8/6 (SMDI/PEG-400) copolymer, (acrylates/steareth-20 methacrylate) copolymer, and (PEG-150/decyl alcohol/SMDI) copolymer;
an oil agent whose content relative to the total mass of the oil-in-water emulsion composition is 0.10% by mass to 10% by mass;
and water, the content of which is 60% by mass or more relative to the total mass of the oil-in-water emulsion composition;
The viscosity measured with a Brookfield viscometer at 25°C is 1,000 mPa·s to 25,000 mPa·s.
Oil-in-water emulsion composition.
[2] The oil-in-water emulsion composition according to [1], wherein the total content of compound II is 0.01% by mass to 0.5% by mass, based on the total mass of the oil-in-water emulsion composition.
[3] The oil-in-water emulsion composition according to [1] or [2], wherein the content of the (sodium acrylate/sodium acryloyldimethyltaurate) copolymer is 0.10% by mass to 1.0% by mass, based on the total mass of the oil-in-water emulsion composition.
[4] The oil-in-water emulsion composition according to any one of [1] to [3], wherein the total content of Compound I is 0.01% by mass to 0.2% by mass, based on the total mass of the oil-in-water emulsion composition.
[5] The oil-in-water emulsion composition according to any one of [1] to [4], wherein the ratio of the total content of Compound I to the content of (sodium acrylate/sodium acryloyldimethyltaurate) copolymer is 0.01 to 2 by mass.
[6] The oil-in-water emulsion composition according to any one of [1] to [5], wherein the ratio of the total content of compound II to the content of (sodium acrylate/sodium acryloyldimethyltaurate) copolymer is 0.01 to 5 by mass.
[7] The oil-in-water emulsion composition according to any one of [1] to [6], wherein the content of betaine is 0.10% by mass to 20% by mass, based on the total mass of the oil-in-water emulsion composition.
[8] The oil-in-water emulsion composition according to any one of [1] to [7], wherein the oil agent comprises a fatty acid ester oil.
[9] The oil-in-water emulsion composition according to any one of [1] to [8], which is a cosmetic.

One embodiment of the present disclosure provides an oil-in-water emulsion composition that has a fresh, moisturizing feel and excellent emulsion stability.

An example of an embodiment of the oil-in-water emulsion composition according to the present disclosure is described below. However, the oil-in-water emulsion composition according to the present disclosure is not limited to the following embodiment, and can be modified as appropriate within the scope of the intended purpose of the present disclosure.

In the present disclosure, a numerical range indicated using "to" means a range that includes the numerical values before and after "to" as the minimum and maximum values, respectively.
In the present disclosure, in the numerical ranges described in stages, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in the numerical ranges described in the present disclosure, the upper or lower limit value of the numerical range may be replaced with the value shown in the examples.
In the present disclosure, the amount of each component in an oil-in-water emulsion composition means the total amount of the multiple substances present in the oil-in-water emulsion composition, unless otherwise specified, when multiple substances corresponding to each component are present in the oil-in-water emulsion composition.
In the present disclosure, a combination of two or more preferred aspects is a more preferred aspect.
In the present disclosure, "mass %" and "weight %" are synonymous.

In the present disclosure, the term "freshness" refers to the sensation of moisture on the skin immediately after application of the oil-in-water emulsion composition.
In the present disclosure, the term "moisturizing feeling" refers to the feeling of continuous moisture on the skin after application of the oil-in-water emulsion composition.
In the present disclosure, "emulsion stability" refers to the property of suppressing separation of an oil-in-water emulsion composition and maintaining an emulsified state when the oil-in-water emulsion composition is left to age. In the present disclosure, "emulsion stability" can be rephrased as "separation resistance." When the oil-in-water emulsion composition is applied to a cosmetic product, it is sufficient that the emulsion stability is maintained at least during the storage period set for the cosmetic product.

In this disclosure, the term "process" refers not only to an independent process, but also to a process that cannot be clearly distinguished from other processes, as long as the intended purpose of that process is achieved.

<Oil-in-water emulsion composition>
The oil-in-water emulsion composition according to the present disclosure comprises:
Betaine and
(Sodium acrylate/sodium acryloyldimethyltaurate) copolymer;
At least one compound I (hereinafter also simply referred to as "compound I") selected from the group consisting of gellan gum and polyacrylamide;
at least one compound II (hereinafter also simply referred to as "compound II") selected from the group consisting of (PEG-240/decyltetradeceth-20/HDI) copolymer, bisstearyl PEG/PPG-8/6 (SMDI/PEG-400) copolymer, (acrylates/steareth-20 methacrylate) copolymer, and (PEG-150/decyl alcohol/SMDI) copolymer;
an oil agent whose content relative to the total mass of the oil-in-water emulsion composition is 0.1% by mass to 10% by mass;
and water, the content of which is 60% by mass or more relative to the total mass of the oil-in-water emulsion composition;
The viscosity measured at 25°C with a Brookfield viscometer is 1,000 mPa·s to 25,000 mPa·s.

The oil-in-water emulsion composition according to the present disclosure has a refreshing feel, excellent moisturizing sensation, and excellent emulsion stability.

Measures for obtaining an oil-in-water emulsion composition that has a refreshing feel when used include, for example, reducing the viscosity of the composition or incorporating small amounts of ingredients such as oils and humectants. However, oil-in-water emulsion compositions that employ such measures tend to lack a moisturizing feel or exhibit reduced emulsion stability. Furthermore, when an oil-in-water emulsion composition is modified to increase the amount of ingredients such as oils and humectants in order to improve the moisturizing feel, or when the viscosity is increased by increasing the amount of emulsifier or adding a thickener in order to improve emulsion stability, the refreshing feel tends to be lost. Furthermore, the more water contained in the composition, the more refreshing the feel can be experienced. When various ingredients such as humectants, emollients, and active ingredients are added to the composition to improve the feel of moisture or to achieve other desired functions, the amount of water is reduced relatively, which can also lead to a reduction in the refreshing feel.

In light of these circumstances, the present disclosure provides an oil-in-water emulsion composition that contains betaine, (sodium acrylate/sodium acryloyldimethyltaurate) copolymer, Compound I, Compound II, a specified amount of oil, and a specified amount of water, and has a viscosity of 1,000 mPa·s to 25,000 mPa·s, thereby providing a fresh feeling, an excellent moisturizing feel, and excellent emulsion stability (resistance to separation).

On the other hand, none of the compositions described in Patent Documents 1 to 3 focus on oil-in-water emulsion compositions that contain betaine, (sodium acrylate/sodium acryloyldimethyltaurate) copolymer, Compound I, Compound II, a specified amount of oil, and a specified amount of water, and have a viscosity of 1,000 mPa·s to 25,000 mPa·s, and are therefore unable to achieve all of the desired freshness, moisturizing feel, and emulsion stability.

The oil-in-water emulsion composition according to the present disclosure is described in detail below.

[(A) Betaine]
The oil-in-water emulsion composition according to the present disclosure contains betaine. By containing betaine, the oil-in-water emulsion composition has excellent freshness and moisturizing feeling and improved emulsion stability. Furthermore, betaine also contributes to suppressing stickiness.

Betaine is trimethylglycine, having the structure shown below, and is sometimes called glycine betaine or betaine anhydrous.

Betaine is an organic compound found in many living organisms. It can be obtained, for example, by extracting and purifying sugar beet molasses.

Betaine (i.e., trimethylglycine) may be a commercially available product. Examples of commercially available betaine include Amicort (trade name) from Asahi Kasei Finechem Co., Ltd. and Betafin BP (trade name) from Ebisu Chemical Industry Co., Ltd.

From the viewpoints of freshness, moisturizing feeling, and emulsion stability, the betaine content is preferably 0.10% to 20% by mass, more preferably 0.50% to 15% by mass, and even more preferably 5.0% to 15% by mass, relative to the total mass of the oil-in-water emulsion composition.

[(B) (Sodium acrylate/sodium acryloyldimethyltaurate) copolymer]
The oil-in-water emulsion composition according to the present disclosure contains a (sodium acrylate/sodium acryloyldimethyltaurate) copolymer, which contributes to freshness and emulsion stability.

Furthermore, the inclusion of (sodium acrylate/sodium acryloyldimethyltaurate) copolymer can contribute to a pseudo-fresh feeling when the oil-in-water emulsion composition is applied to the skin. This is thought to be because the (sodium acrylate/sodium acryloyldimethyltaurate) copolymer has low salt tolerance due to the presence of ionic groups, which causes the viscosity of the oil-in-water emulsion composition to drop instantly when applied to the skin.

(Sodium acrylate/sodium acryloyldimethyltaurate) copolymer is a copolymer of sodium acrylate and sodium acryloyldimethyltaurate.

The (sodium acrylate/sodium acryloyldimethyltaurate) copolymer may be a commercially available product. An example of a commercially available (sodium acrylate/sodium acryloyldimethyltaurate) copolymer is SIMULGEL EG QD from SEPPIC Corporation, which is a mixture containing water and isohexadecene as a solvent.

From the viewpoints of freshness and emulsion stability, the content of (sodium acrylate/sodium acryloyldimethyltaurate) copolymer is preferably 0.10% by mass to 1.0% by mass, more preferably 0.15% by mass to 0.60% by mass, and even more preferably 0.20% by mass to 0.60% by mass, relative to the total mass of the oil-in-water emulsion composition.

[(C) Compound I]
The oil-in-water emulsion composition according to the present disclosure contains at least one compound I selected from the group consisting of gellan gum and polyacrylamide. By containing compound I, the oil-in-water emulsion composition according to the present disclosure has a fresh and moisturizing feel and excellent emulsion stability.

Gellan gum is a polysaccharide produced extracellularly by the microorganism Sphingomonas elodea, and has the property of forming a resilient gel when swollen with water. Known types of gellan gum include native and deacylated forms in which the acetyl and glyceryl groups present in the 1-3 linked glucose are removed. The gellan gum encompassed by Compound I may be either native or deacylated.

Gellan gum may be a commercially available product. Examples of commercially available gellan gum include deacylated Kelcogel "HM" and "CG-HA," and native Kelcogel "LT-100" and "CG-LA" (all manufactured by CP Kelco).

In the present disclosure, polyacrylamide is a general term for polymers containing a structural unit represented by "-CH ₂ -CH(CONH ₂ )-". Polyacrylamide may be a homopolymer or a copolymer. Polyacrylamide may contain a structural unit other than the structural unit represented by "-CH ₂ -CH(CONH ₂ )-". Some of the hydrogen atoms in the structural unit represented by "-CH ₂ -CH(CONH ₂ )-" may be substituted with atoms or atomic groups other than hydrogen atoms, within the scope of the present disclosure.

The oil-in-water emulsion composition according to the present disclosure may contain both gellan gum and polyacrylamide as compound I, or may contain only one of gellan gum and polyacrylamide. From the standpoint of freshness, it is preferable to contain gellan gum.

Any known polyacrylamide can be used as the polyacrylamide, and polyacrylamide that can be used in the fields of cosmetics or quasi-drugs is preferable.

Polyacrylamide may be a commercially available product. Examples of commercially available polyacrylamide include Seppic's composite raw materials Sepigel 305 (polyacrylamide, hydrogenated polyisobutene, laureth-7, water) and Sepigel 501 (polyacrylamide, polysorbate 85, mineral oil, isoparaffin).

The total content of Compound I is preferably 0.01% by mass to 0.2% by mass, more preferably 0.02% by mass to 0.15% by mass, and even more preferably 0.02% by mass to 0.10% by mass, relative to the total mass of the oil-in-water emulsion composition.

From the viewpoints of freshness, moisturizing feeling, and emulsion stability, the ratio [(C)/(B)] of the total content of Compound I (C) to the content of (sodium acrylate/sodium acryloyldimethyltaurate) copolymer (B) is preferably 0.01 to 2 by mass, and more preferably 0.1 to 1.

[(D) Compound II]
The oil-in-water emulsion composition according to the present disclosure contains at least one compound II selected from the group consisting of (PEG-240/decyltetradeceth-20/HDI) copolymer, bisstearyl PEG/PPG-8/6 (SMDI/PEG-400) copolymer, (acrylates/steareth-20 methacrylate) copolymer, and (PEG-150/decyl alcohol/SMDI) copolymer. PEG is an abbreviation for polyethylene glycol, PPG is an abbreviation for polypropylene glycol, HDI is an abbreviation for hexamethylene diisocyanate, and SMDI is an abbreviation for methylene diphenyl diisocyanate. By containing compound II, the oil-in-water emulsion composition according to the present disclosure has a fresh, moisturizing feel and excellent emulsion stability. Among these, (PEG-240/decyltetradeceth-20/HDI) copolymer is particularly preferred.

Compounds included in Compound II are compounds that can function as associative thickeners. An associative thickener is a polymer that has a hydrophobic moiety at the end of a molecular chain containing a hydrophilic moiety (e.g., a polyether chain), and exhibits a thickening effect in aqueous liquids when the hydrophobic moieties associate with each other or with a hydrophobic substance.

Compound II may be commercially available.
Commercially available (PEG-240/decyltetradeceth-20/HDI) copolymers include, for example, ADEKA Corporation's ADEKA NOL GT-700 and a composite raw material, ADEKA NOL GT-730 ((PEG-240/decyltetradeceth-20/HDI) copolymer, BG, water).
An example of a commercially available product of bisstearyl PEG/PPG-8/6 (SMDI/PEG-400) copolymer is AQUPEC (registered trademark) HU C2002 (Sumitomo Seika Chemicals Co., Ltd.).
Commercially available acrylates/steareth-20 methacrylate copolymers include, for example, ACULYN® 22 RHEOLOGY MODIFIER (Dow Chemicals).
A commercially available example of the (PEG-150/decyl alcohol/SMDI) copolymer is ACULYN® 44 (DOW CHEMICALS).

From the viewpoints of freshness, moisturizing feeling, and emulsion stability, the content of Compound II is preferably 0.01% by mass to 0.5% by mass, more preferably 0.05% by mass to 0.25% by mass, and even more preferably 0.05% by mass to 0.20% by mass, relative to the total mass of the oil-in-water emulsion composition.

From the viewpoints of freshness, moisturizing feeling, and emulsion stability, the ratio [(D)/(B)] of the total content of Compound II (D) to the content (B) of (sodium acrylate/sodium acryloyldimethyltaurate) copolymer is preferably 0.01 to 5 by mass, and more preferably 0.1 to 1.

From the viewpoint of freshness and anti-stickiness effects, the ratio [(D)/(C)] of the total content of compound II (D) to the total content of compound I (C) is preferably 0.60 to 5.0 by mass, and more preferably 1.0 to 4.0.

[(E) Oil]
The oil-in-water emulsion composition according to the present disclosure contains an oil, and the content of the oil relative to the total mass of the oil-in-water emulsion composition is 0.10% by mass to 10% by mass.

In this disclosure, the term "oil" is used to collectively refer to a group of compounds consisting of hydrocarbon oils, ester oils, silicone oils, animal and vegetable oils, higher fatty acids, and higher alcohols. The oils used in this disclosure may be selected from, for example, compounds belonging to these groups that have a proven track record of being commonly used as oils in the fields of cosmetics or quasi-drugs.

The oil-in-water emulsion composition according to the present disclosure may contain one type of oil agent alone, or two or more types.

The oil may be liquid, semi-solid, or solid at room temperature (25°C, same below). The oil may be a commercially available product or a synthetic product.

The oil agent is preferably at least one selected from the group consisting of hydrocarbon oils, ester oils, and animal and vegetable oils.

From the perspective of freshness, the oil preferably contains an ester oil, and more preferably contains an ester oil that is liquid at room temperature. Ester oil refers to an oil that has an ester bond in its molecular structure.

Examples of hydrocarbon oils include liquid paraffin, isoparaffin, ethylene-propylene copolymer, hydrogenated polyisobutene, squalane, petrolatum, paraffin wax, ceresin wax, microcrystalline wax, Fischer-Tropsch wax, and polyethylene wax.

Ester oils are made from a variety of esters that combine acids such as fatty acids and polybasic acids with alcohols such as lower alcohols, higher alcohols, and polyhydric alcohols.

Ester oils include, for example, isopropyl myristate, octyldodecyl myristate, cholesteryl stearate, tricaprylin, diethylhexyl succinate, diisopropyl adipate, diisobutyl adipate, diisostearyl malate, neopentyl glycol diethylhexanoate, pentaerythrityl tetraethylhexanoate, cetyl ethylhexanoate, caprylic/capric triglyceride, phytosteryl/octyldodecyl lauroyl glutamate, triisostearin, glyceryl stearate, glyceryl diisostearate, and triethylhexanoin. Ingredients include phytosteryl/behenyl dimer dilinoleate, phytosteryl/isostearyl/cetyl/stearyl/behenyl dimer dilinoleate, isopropyl palmitate, phytosteryl macadamiate, pentaerythrityl tetrabehenate/benzoate/ethylhexanoate, ethylhexyl palmitate, myristyl myristate, tripropylene glycol dipivalate, isotridecyl isononanoate, pentaerythritol rosinate, glyceryl behenate/eicosanedioate, and polyglyceryl-10 behenate/eicosanedioate.

Examples of silicone oils include linear polysiloxanes such as dimethylpolysiloxane (dimethicone, methylphenylpolysiloxane, decamethyltetrasiloxane, and methylhydrogenpolysiloxane), cyclic polysiloxanes such as octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, and tetramethyltetrahydrogencyclotetrasiloxane, and caprylyl methicone.

Examples of animal and vegetable oils include jojoba seed oil, avocado oil, almond oil, olive oil, cocoa oil, sesame oil, wheat germ oil, safflower oil, shea butter, turtle oil, camellia oil, persic oil, castor oil, grape oil, macadamia nut oil, palm oil, rosehip oil, soybean oil, egg yolk oil, hydrogenated castor oil, hydrogenated palm oil, hydrogenated cocoa oil, hydrogenated turtle oil, hydrogenated mink oil, cow tallow, mink oil, lanolin (also known as wool fat), beeswax, Japan wax, gay wax, carnauba wax, candelilla wax, and montan wax.

Examples of higher fatty acids include stearic acid, lauric acid, myristic acid, palmitic acid, oleic acid, isostearic acid, hydroxystearic acid, and behenic acid.

Examples of higher alcohols include cetyl alcohol, stearyl alcohol, myristyl alcohol, oleyl alcohol, isostearyl alcohol, lauryl alcohol, and behenyl alcohol.

In one embodiment, the oil is preferably at least one selected from the group consisting of triethylhexanoin, tri(caprylic/capric)glyceryl, and diethylhexyl succinate.

From the viewpoint of freshness, the content of the oil is preferably 0.10% to 10% by mass, and more preferably 1.0% to 7.5% by mass, relative to the total mass of the oil-in-water emulsion composition.

[(F) Water]
The oil-in-water emulsion composition according to the present disclosure contains water, and the water content relative to the total mass of the oil-in-water emulsion composition is 60 mass % or more.

There are no particular restrictions on the type of water used, and natural water, purified water, distilled water, ion-exchanged water, pure water, ultrapure water (such as Milli-Q water), etc. can be used. Milli-Q water is ultrapure water obtained using a Milli-Q water production system manufactured by Merck Millipore, a company owned by Merck & Co.

The water contained in the oil-in-water emulsion composition is preferably purified water, distilled water, ion-exchanged water, pure water, or ultrapure water, as these contain fewer impurities.

From the perspective of freshness, a larger amount of water is preferable. The water content in the oil-in-water emulsion composition according to the present disclosure is preferably 60% by mass or more, and more preferably 70% by mass or more, based on the total mass of the oil-in-water emulsion composition. The upper limit of the water content is not particularly limited, but can be, for example, 90% by mass.

[Other added ingredients]
The oil-in-water composition according to the present disclosure may contain other additive components in addition to betaine, (sodium acrylate/sodium acryloyldimethyltaurate) copolymer, Compound I, Compound II, oil, and water.

Other additive ingredients include, for example, additive ingredients commonly used in cosmetics or quasi-drugs. Other additive ingredients include, for example, functional ingredients that exhibit useful beauty effects (e.g., moisturizing effects, skin conditioning effects, etc.) when used in cosmetics. Further additive ingredients include whitening agents such as tranexamic acid and arbutin, anti-inflammatory agents such as stearyl glycyrrhetinate, dipotassium glycyrrhizinate, and allantoin, surfactants such as polyglycerin fatty acid esters and lecithin, carotenoids such as astaxanthin, preservatives such as phenoxyethanol and ethylhexylglycerin, vitamin E compounds such as tocopherol, polyhydric alcohols, colorants, thickeners, pH adjusters such as sodium hydroxide and hydrochloric acid, buffers, fragrances, antibacterial agents, ultraviolet absorbers, active oxygen scavengers, antimicrobial agents, and minerals.

Additive components may be added directly to the oil-in-water composition, or may be added in the form of microcapsules, liposomes, etc., in which the additive components are encapsulated. Liposomes may have a single-lamellar structure, in which the lipid bilayer is single, or a multi-lamellar structure, in which the lipid bilayer is multiple. However, from the perspective of the amount of component encapsulation, liposomes with a single-lamellar structure are preferred. Liposomes can be manufactured based on or with reference to known manufacturing methods for liposomes.

[viscosity]
The oil-in-water emulsion composition according to the present disclosure has a viscosity (hereinafter also simply referred to as "viscosity") of 1,000 mPa·s to 25,000 mPa·s as measured with a Brookfield viscometer at 25°C. A viscosity of 1,000 mPa·s to 25,000 mPa·s contributes to both freshness and emulsion stability.

In this disclosure, the viscosity of an oil-in-water emulsion composition is measured using the following method and conditions.

-Measurement method-
50 g of the oil-in-water emulsion composition is filled into a glass container having a diameter of 40 mm and a height of 75 mm, sealed, and stored for 24 hours in an environment of 25° C. After storage, the viscosity of the oil-in-water emulsion composition is measured using a Brookfield viscometer under the following measurement conditions.
- Measurement conditions -
Measurement temperature: 25℃
Rotor: M3 rotor,
Rotation speed: 12 rpm (revolutions per minute, same below)
Rotation time: 60 seconds B-type viscometer: B-type viscometer "TV-10M" manufactured by Toki Sangyo Co., Ltd.

The viscosity of the oil-in-water emulsion composition is 1,000 mPa·s to 25,000 mPa·s, more preferably 1,500 mPa·s to 20,000 mPa·s, and even more preferably 2,000 mPa·s to 10,000 mPa·s.

[Uses of oil-in-water emulsion composition]
The oil-in-water emulsion composition according to the present disclosure can be applied to cosmetic products such as cosmetics and quasi-drugs, for example.

Cosmetics incorporating the oil-in-water emulsion composition of the present disclosure have a fresh, moisturizing feel and excellent emulsion stability.

Applications of cosmetics include, but are not limited to, skin care cosmetics (skin lotion, emulsion, serum, sunscreen, pack, etc.), body cosmetics (body lotion, body sunscreen, etc.), and scalp cosmetics.

[Method of producing oil-in-water emulsion composition]
The method for producing the oil-in-water emulsion composition according to the present disclosure is not particularly limited.
The oil-in-water emulsion composition according to the present disclosure can be produced using betaine, (sodium acrylate/sodium acryloyldimethyltaurate) copolymer, Compound I, Compound II, an oil, water, and, if desired, the above-mentioned additive components, according to a known method for producing an oil-in-water emulsion composition.

A preferred method for producing the oil-in-water emulsion composition according to the present disclosure is, for example, a method in which an aqueous phase composition containing at least betaine, (sodium acrylate/sodium acryloyldimethyltaurate) copolymer, Compound I, Compound II, and water is mixed with an oil phase composition containing at least an oil agent, and emulsified and dispersed.

The aqueous phase composition can be prepared, for example, by mixing betaine, (sodium acrylate/sodium acryloyldimethyltaurate) copolymer, Compound I, Compound II, water, and aqueous additive components among the additive components that are optionally blended.
When preparing the aqueous phase composition, all of the components to be incorporated into the aqueous phase composition may be mixed at once, or each component to be incorporated into the aqueous phase composition may be mixed in several batches.
The components to be blended in the aqueous phase composition may be simply mixed in the aqueous phase composition, but it is preferable that they are mixed uniformly.
The mixing method is not particularly limited, and any commercially available mixing means may be used.
Examples of the mixing means include a stirrer, a paddle mixer, an impeller mixer, a homomixer, a disper mixer, an ultra mixer, a high-pressure homogenizer, an ultrasonic homogenizer, etc. Among these, the mixing means is preferably at least one selected from the group consisting of a homomixer and a disper mixer.

When compound I is mixed with water and other components to be contained in the aqueous phase composition, the stirring temperature is preferably set to 70° C. to 90° C. The temperature when mixing the other components is not particularly limited and can be set appropriately depending on the components to be mixed, etc.
The means for adjusting the temperature is not particularly limited.
A common heating device (for example, a water bath) can be used to adjust the temperature.

The stirring conditions for mixing the components are not particularly limited as long as they are thoroughly mixed, and can be set appropriately depending on the mixing method. For example, when using a homomixer as the mixing method, the components can typically be stirred at 500 rpm (revolutions per minute; hereinafter the same) to 8000 rpm for 5 to 60 minutes.

The oil phase composition can be prepared, for example, by mixing an oil agent with an oily additive component among the optional additive components. Note that a preparation using only a single oil agent as the oil phase component is also included in one embodiment of the oil phase composition of the present disclosure.
When preparing the oil phase composition, all of the components to be incorporated into the oil phase composition may be mixed at once, or each component to be incorporated into the oil phase composition may be mixed in several batches.
The components to be blended in the oil phase composition may be simply mixed in the oil phase composition, but it is preferable that they are mixed uniformly.
The mixing method is not particularly limited, and any commercially available mixing means may be used.
Examples of the mixing means include a stirrer, a paddle mixer, an impeller mixer, a homomixer, a disper mixer, an ultra mixer, a high-pressure homogenizer, an ultrasonic homogenizer, etc. Among these, the mixing means is preferably at least one selected from the group consisting of a homomixer and a disper mixer.

The stirring temperature is not particularly limited as long as it is a temperature condition that allows uniform mixing and dispersion, but it is preferable to set it to, for example, 60°C to 90°C.
The means for adjusting the temperature is not particularly limited.
A common heating device (for example, a water bath) can be used to adjust the temperature.
The stirring time is not particularly limited and can be appropriately set depending on the type of stirring tool or stirring device, the composition of the oil phase composition, and the like.
A preferred example of the stirring temperature and stirring time is a stirring temperature of 80° C. and a stirring time of 1 hour.

The method of emulsification and dispersion is not particularly limited.
Although emulsification and dispersion may be carried out by a step of mixing the oil phase composition and the aqueous phase composition all at once, it is preferable to carry out emulsification and dispersion by a step of stirring the aqueous phase composition and adding the oil phase composition little by little to the stirred aqueous phase composition while mixing.
For emulsification and dispersion, a conventional emulsification means utilizing shearing action, such as a stirrer, impeller, homomixer, or continuous flow shearing device, can be used.
For the purpose of further uniforming the particle size, the emulsification dispersion may be carried out multiple times.

The ratio of the oil phase composition to the aqueous phase composition (oil phase composition/aqueous phase composition) is not particularly limited, but is preferably 1/99 to 50/50 by mass, more preferably 3/97 to 40/60, even more preferably 5/95 to 30/70, and particularly preferably 10/90 to 20/80.

The method for producing an oil-in-water emulsion composition according to the present disclosure may include steps other than the step of mixing the oil phase composition and the aqueous phase composition (so-called other steps) as needed.
Examples of other steps include a degassing step, a heat sterilization step, a cooling step, a removal step, etc. Methods known in the art may be applied to the degassing step, heat sterilization step, cooling step, removal step, etc.

The oil-in-water emulsion composition according to the present disclosure will be explained in more detail below using examples, but the oil-in-water emulsion composition according to the present disclosure is not limited to the following examples.

Example 1
Of the ingredients listed in Table 1 below, betaine and water were mixed and stirred for 10 minutes using a stirrer in a water bath at 80°C. To the resulting mixture, gellan gum and (PEG-240/decyltetradeceth-20/HDI) copolymer were added, and the mixture was stirred at 4000 rpm for 20 minutes using a homomixer (model name: Homomixer MARK II 2.5, Primix Corporation). Next, (sodium acrylate/sodium acryloyldimethyltaurate) copolymer was added, and the mixture was mixed at 4000 rpm for 5 minutes using a homomixer to obtain an aqueous phase composition.

Next, among the components listed in Table 1 below, triethylhexanoin, an oil (ester oil), was placed in a container and heated and stirred for 10 minutes using a stirrer in a water bath at 80°C to obtain an oil phase composition.
Next, the aqueous phase composition was stirred at 4000 rpm using a homomixer, and the oil phase composition was added little by little to the stirred aqueous phase composition. After the addition, the mixture was stirred and mixed at 4000 rpm for 20 minutes to obtain an oil-in-water emulsion composition of Example 1.

[Examples 2 to 21 and Comparative Examples 1 to 14]
The oil-in-water emulsion compositions of Examples 2 to 21 and the comparative compositions of Comparative Examples 1 to 14 were obtained in the same manner as in Example 1, except that in the preparation of the oil-in-water emulsion composition of Example 1, the components and their blending amounts were appropriately changed so as to obtain the compositions shown in Tables 1 to 6 below.

[Evaluation and Measurement]
The oil-in-water emulsion compositions obtained in the examples and the comparative compositions obtained in the comparative examples were used as evaluation samples to carry out the following evaluations and measurements. The results are shown in Tables 1 to 6.

The unit (%) for the amount of each component listed in Tables 1 to 6 is "% by mass," and the amount of water makes the total amount of each composition 100% by mass.

In Tables 1 to 6, a "-" in the composition column means that the corresponding ingredient is not included.

In addition, Example 1 listed in Tables 2-3 and Tables 5-6 is listed for comparison with the Examples and Comparative Examples listed in each table, and is the same as Example 1 listed in Table 1.

1. Evaluation of physical properties immediately after preparation (initial physical properties) 1-1. Viscosity The viscosity was measured by the following measurement method and measurement conditions.

-Measurement method-
50 g of the evaluation sample was filled into a glass container having a diameter of 40 mm and a height of 75 mm, sealed, and stored for 24 hours in an environment of 25° C. After storage, the viscosity of each evaluation sample was measured using a Brookfield viscometer under the following measurement conditions.

- Measurement conditions -
Measurement temperature: 25℃
Rotor: M3 rotor,
Rotation speed: 12 rpm
Rotation time: 60 seconds B-type viscometer: B-type viscometer "TV-10M" manufactured by Toki Sangyo Co., Ltd.

The evaluation samples were visually observed, and the particle size (median size) of the emulsified particles was measured using a laser diffraction/scattering particle size distribution analyzer, and the emulsification properties were evaluated according to the following ranks, with "A" being the most excellent rank.

The laser diffraction/scattering particle size distribution analyzer used was a laser diffraction/scattering particle size distribution analyzer manufactured by Horiba, Ltd. (product name: LA960).

~Rank~
A: No oil floating was observed, and the particle size of the emulsified particles was less than 5 μm.
B: No oil floating was observed, and the particle size of the emulsified particles was 5 μm or more and less than 10 μm.
C: Oil floating was observed and the particle size of the emulsified particles was 10 μm or more.

2. Evaluation of Feeling in Use The feeling in use of the evaluation samples, specifically, freshness, moisturizing feeling, and stickiness, was evaluated as follows.

2-1. Freshness The evaluation samples immediately after preparation were used by 10 monitors in the following manner to evaluate freshness.
Specifically, the monitors were asked to take 100 μL of the evaluation sample on their fingers and spread it on the inside of the forearm of the opposite arm, and the degree of moisture felt on the skin after application (i.e., freshness) was used to evaluate the freshness using the following rankings.
The rank selected by each monitor most frequently was regarded as the result of the freshness evaluation, and if the number of selections was the same, the better rank was regarded as the result of the freshness evaluation. The best evaluation rank was "A".

~Rank~
A: I feel a strong sense of freshness.
B: It feels fresh.
C: Slightly refreshing feeling.
D: Doesn't feel fresh.

2-2. Moisture Sensation Immediately after preparation, the evaluation samples were used by 10 monitors in the following manner to evaluate the moisture sensation.
Specifically, the monitors were asked to take 100 μL of the evaluation sample on their fingers and spread it on the inside of the forearm of the opposite arm, and the feeling of lasting moisture on the skin after application (i.e., moisturizing feeling) was evaluated using the following evaluation ranks.
The rank selected by each monitor most frequently was regarded as the evaluation result of the moisturizing feeling, and in the case of the same number of selections, the better rank was regarded as the evaluation result of the moisturizing feeling. The best evaluation rank was "A".

~Rank~
A: I feel a strong moisturizing sensation.
B: Feels moisturizing.
C: Slight moisturizing sensation.
D: No moisturizing feeling.

2-3. Stickiness Immediately after preparation, the evaluation samples were used by 10 monitors in the following manner to evaluate stickiness.
Specifically, the monitors were asked to take 100 μL of the evaluation sample on their fingers and spread it on the inside of the forearm of the opposite arm, and the stickiness of the skin surface during spreading or after application was evaluated using the following rankings.
The rank selected by each monitor most frequently was regarded as the evaluation result for stickiness, and if the number of selections was the same, the better rank was regarded as the evaluation result for stickiness. The best evaluation rank was "A".

~Rank~
A: It doesn't feel sticky.
B: Almost no stickiness is felt.
C: Slight stickiness is felt.
D: Feels sticky.

3. Evaluation of emulsion stability (separation resistance) A specified amount of the evaluation sample was filled into a disposable cell (made of polycarbonate, optical path length 10 mm) designed specifically for the Lumicizer device. The disposable cell filled with the evaluation sample was set in a Lumicizer, a particle size distribution analyzer for multiple samples and dispersibility evaluation manufactured by LUM JAPAN Co., Ltd., and the device was operated under the following measurement conditions to perform a measurement process and obtain a transmitted light profile. The change in transmittance before and after the measurement process obtained from the transmitted light profile of each evaluation sample was used as an index, and emulsion stability (separation resistance) was evaluated using the following evaluation ranks. A smaller change in transmittance means that no separation occurred in the evaluation sample. The best evaluation rank is "A."
- Measurement conditions -
Measurement temperature: 25℃
Gravitational acceleration: ×2300g
Operating time: 632 minutes

~Rank~
A: The change in transmittance is less than 10. B: The change in transmittance is 10 or more but less than 20. C: The change in transmittance is 20 or more.

The results shown in Tables 1 to 6 reveal the following.
Each of the oil-in-water emulsion compositions of the Examples had a fresh feeling, an excellent moisturizing feel, and excellent emulsion stability.
On the other hand, Comparative Example 1, which did not contain betaine, did not provide a moisturizing feeling and was also poor in emulsion stability.
Comparative Examples 2 and 3, which did not contain the (sodium acrylate/sodium acryloyldimethyltaurate) copolymer, and Comparative Examples 4 and 5, which used other polymers instead of the (sodium acrylate/sodium acryloyldimethyltaurate) copolymer, were unable to achieve both freshness and emulsion stability. Comparative Examples 2 and 3 also had poor emulsifiability immediately after preparation.
Comparative Examples 6 and 7, which did not contain Compound I, and Comparative Examples 8 to 12, which used other components instead of Compound I, all had poor emulsion stability.
Comparative Example 13, which did not contain Compound II, did not provide a moisturizing feeling and was also poor in emulsion stability.
In Comparative Example 14, in which the content of the oil exceeded 10% by mass, no fresh feeling was obtained.

The details of each component shown in Tables 1 to 6 will be explained below.
- Betaine (Amicort, Asahi Kasei Finechem Co., Ltd.)
- (Sodium acrylate/sodium acryloyldimethyltaurate) copolymer (SIMULGEL EG QD, SEPPIC)
Acrylates/C10-30 alkyl acrylate crosspolymer (PEMULEN TR-2, Loop Resor Co., Ltd.)
Carbomer (Carbopol 980, Loop Resor Co., Ltd.)
Gellan gum (Kelcogel HM, CP Kelco, Compound I)
Polyacrylamide (SEPIGEL 305, SEPPIC, Compound I)
・Xanthan gum (Nomcoat ZZ, Nisshin Oillio Group Co., Ltd.)
・Agar (Ina Agar CS-120, Ina Foods)
Locust bean gum (GENUGUM RL-200-Z, Sansho Co., Ltd.)
Sodium dilauramidoglutamide lysine (Pellicer® L-30, Asahi Kasei Finechem)
(PEG-240/Decyltetradeceth-20/HDI) copolymer (GT-700, ADEKA Corporation, Compound II)
Bisstearyl PEG/PPG-8/6 (SMDI/PEG-400) copolymer (AQUPEC® HU C200, Sumitomo Seika Chemicals Co., Ltd., Compound II)
Acrylates/steareth-20 methacrylate copolymer (ACULYN® 22 RHEOLOGY MODIFIER, The Dow Chemical Company, Compound II)
PEG-150/Decyl Alcohol/SMDI Copolymer (ACULYN® 44, Dow Chemicals, Compound II)
Triethylhexanoin (TIO, Nisshin Oillio Group, Ltd., oil)
・Caprylic/capric triglyceride (Coconard MT, Kao, oil)
Diethylhexyl succinate (KAK DIOS, Kokyu Alcohol Kogyo Co., Ltd., oil)
・Squalane (NIKKOL refined olive squalane, Nikko Chemicals Co., Ltd., oil)

Example 22
1. Preparation of liposome-containing composition A An oil phase composition A, an aqueous phase composition A-1, and an aqueous phase composition A-2 were each prepared, and the resulting oil phase composition A, aqueous phase composition A-1, and aqueous phase composition A-2 were mixed, stirred, emulsified, and allowed to form liposomes, thereby preparing liposome-containing composition A.

(Preparation of Oil Phase Composition A)
Polyoxyethylene phytosterol (average number of moles of oxyethylene groups added: 20), hydrogenated lecithin (hydrogenated soybean phospholipid, phosphatidylcholine content: 90% or more), cholesterol, ascorbyl tetra-2-hexyldecanoate, stearyl glycyrrhetinate, and absolute ethanol were mixed and dissolved by heating at 60°C for 10 minutes, thereby obtaining an oil phase composition A.

(Preparation of aqueous phase compositions A-1 and A-2)
Disodium hydrogen phosphate anhydrous, sodium dihydrogen phosphate, tranexamic acid (Maruzen Pharmaceuticals Co., Ltd.), Sanguisorba officinalis extract (Jiyu Extract Powder, Maruzen Pharmaceuticals Co., Ltd.), and purified water were mixed and dissolved by heating at 60°C for 10 minutes, to obtain aqueous phase composition A-1.
Also, methyl parahydroxybenzoate and purified water were mixed and dissolved by heating at 60° C. for 10 minutes to obtain aqueous phase composition A-2.

(Preparation of Liposome-Containing Composition A)
The aqueous phase composition A-1 obtained above was stirred with a homomixer (3400 rpm) while being kept at 60°C, and then the oil phase composition A was added to the aqueous phase composition A-1.
After the addition, stirring was continued for 45 minutes at 3400 rpm. After stirring, the mixture was cooled to 35°C or below, and after cooling, aqueous phase composition A-2 was added. The mixture was homogenized by stirring and mixing, and then filtered through a 230 mesh filter cloth to obtain a cosmetic composition (liposome-containing composition A).

[Composition] [Content (mass%)]
・Polyoxyethylene phytosterol 0.05
・Hydrogenated lecithin 0.55
・Cholesterol 0.15
Glyceryl tetra-2-hexyldecanoate 0.05
・Stearyl glycyrrhetinate 0.0025
・Absolute ethanol 10.05
Disodium hydrogen phosphate anhydrous 0.065
・Sodium dihydrogen phosphate 0.003
Tranexamic acid 0.050
Sanguisorba officinalis extract 0.05
・Methylparaben 0.2
・Remaining purified water

2. Preparation of oil-in-water emulsion composition An oil-in-water emulsion composition having the following composition was prepared (total amount 100% by mass).
[Composition] [Content (mass%)]
(Sodium acrylate/sodium acryloyldimethyltaurate) copolymer 0.35
・Gellan gum 0.10
・(PEG-240/Decyltetradeceth-20/HDI) copolymer 0.15
・Triethylhexanoin 5.0
・Caprylic/capric triglyceride 1.0
・Glycerin 2.0
・1,3 Butylene Glycol 10.0
・Betaine 10.0
Tranexamic acid 2.0
・Glycyrrhetinic acid stearyl 0.1
γ-oryzanol 0.001
・Lecithin 0.01
・Polyglyceryl-10 oleate 0.01
・Sucrose stearate 0.01
Liposome-containing composition A (prepared as above) 1.0
・Phenoxyethanol 0.20
・Methylparaben 0.10
・Fragrance (appropriate amount) ・Remaining amount of water

Claims (5)

betaine , the content of which is 0.10% by mass to 20% by mass relative to the total mass of the oil-in-water emulsion composition ;
a (sodium acrylate/sodium acryloyldimethyltaurate) copolymer in an amount of 0.10% by mass to 1.0% by mass relative to the total mass of the oil-in-water emulsion composition ;
at least one compound I selected from the group consisting of gellan gum and polyacrylamide , the content of which is 0.01% by mass to 0.2% by mass relative to the total mass of the oil-in-water emulsion composition ;
at least one compound II selected from the group consisting of (PEG-240/decyltetradeceth-20/HDI) copolymer, bisstearyl PEG/PPG-8/6 (SMDI/PEG-400) copolymer, (acrylates/steareth-20 methacrylate ) copolymer, and (PEG-150/decyl alcohol/SMDI) copolymer, the content of which is 0.01% by mass to 0.5% by mass relative to the total mass of the oil-in-water emulsion composition;
an oil agent whose content relative to the total mass of the oil-in-water emulsion composition is 0.10% by mass to 10% by mass;
and water, the content of which is 60% by mass or more relative to the total mass of the oil-in-water emulsion composition;
The viscosity measured with a Brookfield viscometer at 25°C is 1,000 mPa·s to 25,000 mPa·s.
Oil-in-water emulsion composition. 2. The oil-in-water emulsion composition according to claim 1 , wherein the ratio of the total content of Compound I to the content of (sodium acrylate/sodium acryloyldimethyltaurate) copolymer is 0.01 to 2 on a mass basis. 3. The oil-in-water emulsion composition according to claim 1 or claim 2 , wherein the ratio of the total content of compound II to the content of (sodium acrylate/sodium acryloyldimethyltaurate) copolymer is 0.01 to 5 on a mass basis. The oil-in-water emulsion composition according to any one of claims 1 to 3 , wherein the oil comprises an ester oil. The oil-in-water emulsion composition according to any one of claims 1 to 4 , which is a cosmetic.