Water-in-oil type emulsion cosmetic material

Abstract

Provided is a water-in-oil type emulsion cosmetic material having excellent base agent stability and usability. The water-in-oil type emulsion cosmetic material according to the present disclosure comprises: (A) a spherical inorganic powder that is at least one selected from the group consisting of non-porous silica particles and solid borosilicate particles; and (B) at least one thickener selected from the group consisting of acrylamide-based polymers and acrylic acid-based polymers having no emulsification ability.

Description

Water-in-oil emulsion cosmetics

[0001] The present disclosure relates to a water-in-oil emulsion cosmetic.

[0002] Water-in-oil emulsion cosmetics have superior water resistance compared to oil-in-water emulsion cosmetics, and are characterized by the ability to efficiently incorporate emollient oils, oil-soluble drugs, UV absorbers, etc., and therefore can be used as cosmetics with a high skin care effect. However, water-in-oil emulsion cosmetics are prone to separation of the oil and water phases, and excellent base stability is often required (Patent Document 1).

[0003] Furthermore, water-in-oil emulsion cosmetics are widely used in makeup cosmetics such as foundations and skin care creams, but these applications require excellent usability (elasticity and fit) when spreading.

[0004] International Publication No. 2020 / 100573

[0005] The present disclosure has been made in view of the above circumstances, and an object of the present disclosure is to provide a water-in-oil emulsion cosmetic that is excellent in base stability and ease of use.

[0006] In order to solve the above problems, the present inventors have conducted extensive research and found that the above problems can be solved by using a specific spherical inorganic powder (A) in combination with a specific thickener (B), and have thus completed the present disclosure. Specifically, the present disclosure provides the following.

[0007] [1] A water-in-oil emulsion cosmetic comprising: (A) at least one type of spherical inorganic powder selected from the group consisting of nonporous silica particles and solid borosilicate particles; and (B) at least one type of thickener not having emulsifying ability selected from the group consisting of acrylamide-based polymers and acrylic acid-based polymers.

[0008] [2] The specific surface area of ​​the spherical inorganic powder (A) is 100 m ２ / g or less.

[0009] [3] The cosmetic according to [1] or [2], wherein the oil absorption of the spherical inorganic powder (A) is 50 mL / 100 g or less.

[0010] [4] The cosmetic according to any one of [1] to [3], wherein the content of the spherical inorganic powder (A) is 1 to 10% by mass.

[0011] [5] The cosmetic preparation according to any one of [1] to [4], wherein the content of the thickener (B) is 0.05 to 0.5% by mass.

[0012] [6] The cosmetic according to any one of [1] to [5], wherein the viscosity of the cosmetic is 15,000 mPa·s or more.

[0013] According to the present disclosure, it is possible to provide a water-in-oil emulsion cosmetic that is excellent in base stability and usability.

[0014] Hereinafter, embodiments of the present disclosure will be described in detail, but the present disclosure is not limited to the following embodiments and can be implemented with appropriate modifications within the scope of the purpose of the present disclosure.

[0015] <Water-in-oil emulsion cosmetic> The water-in-oil emulsion cosmetic of the present disclosure (hereinafter also referred to as the "cosmetic of the present disclosure") comprises (A) at least one type of spherical inorganic powder selected from the group consisting of nonporous silica particles and solid borosilicate particles (hereinafter also referred to as the "inorganic powder (A)"), and (B) at least one type of thickener that does not have emulsifying ability and is selected from the group consisting of acrylamide-based polymers and acrylic acid-based polymers (hereinafter also referred to as the "thickener (B)").

[0016] <Inorganic Powder (A)> The cosmetic preparation of the present disclosure contains at least one spherical inorganic powder selected from the group consisting of nonporous silica particles and solid borosilicate particles. By incorporating these spherical inorganic powders, excellent base stability can be achieved. Furthermore, cosmetics incorporating these spherical inorganic powders have a moist, soft, elastic feel and a fitting sensation, and are excellent in usability.

[0017] In the present disclosure, the spherical shape of the spherical inorganic powder includes not only a perfect sphere but also an approximately sphere, an oval sphere, and the like.

[0018] In the present disclosure, the term "non-porous" in non-porous silica particles means that the particles have far fewer pores than porous silica particles, which are silica particles generally used in cosmetics, and does not mean that there are no pores at all on the surface of the silica particles. ２ / g or less (preferably 50m ２ / g or less), it can be said to be non-porous.

[0019] Examples of borosilicate salts include salts of alkali metals such as Na and K, salts of alkaline earth metals such as Mg and Ca, Al salts, and combinations of these salts. Among these, Na borosilicate, Ca borosilicate, Al borosilicate, (Ca / Na) borosilicate, and (Ca / Al) borosilicate are preferred, with (Ca / Na) borosilicate being more preferred.

[0020] The specific surface area of ​​the inorganic powder (A) is preferably 100 m ２ / g or less, more preferably 50m ２ / g or less, more preferably 10m ２ / g or less, particularly preferably 2.5m ２ / g or less, particularly preferably 2.5m ２ / g, most preferably less than 2.3 m ２ / g or less. ２ When the specific surface area of ​​the inorganic powder (A) is 0.01 m / g or less, the cosmetic containing the inorganic powder (A) is likely to have a moist, soft, elastic feel and a good fit, and is likely to have excellent usability. ２ / g or more, 0.05m ２ / g or more, or 0.1m ２ In the present disclosure, the specific surface area of ​​the inorganic powder (A) is a value calculated by measuring the nitrogen adsorption amount of the powder at 77 K using a specific surface area meter and analyzing it by the BET method.

[0021] The oil absorption of the inorganic powder (A) is preferably 50 mL / 100 g or less, more preferably 40 mL / 100 g or less, and even more preferably 30 mL / 100 g or less. When the oil absorption of the inorganic powder (A) is 50 mL / 100 g or less, excellent base stability is easily obtained. In addition, the lower limit of the oil absorption of the inorganic powder (A) is not particularly limited, but is, for example, 1 mL / 100 g or more, 5 mL / 100 g or more, or 10 mL / 100 g or more. In the present disclosure, the oil absorption of the inorganic powder (A) is a value calculated by the following method. Squalane is added dropwise to about 4 g of inorganic powder (A) and kneaded. This dropping and kneading is repeated, and the end point is when the inorganic powder (A) becomes one continuous piece, and the oil absorption is calculated using the following formula. Oil absorption (ml / 100g) = (A / W) x 100 (wherein A represents the amount of squalane dropped (mL), and W represents the mass (g) of the inorganic powder (A).)

[0022] The average particle size of the inorganic powder (A) is not particularly limited, but is, for example, 0.1 to 30 μm, 1 to 15 μm, or 3 to 12 μm. In the present disclosure, the average particle size of the inorganic powder (A) is a value measured as a volume average particle size (D50) using a laser diffraction / scattering particle size distribution analyzer (MT3300EXII; manufactured by Microtrack Bell).

[0023] The inorganic powder (A) may be surface-treated. Specifically, the surface treatment refers to the introduction of a compound onto the surface of the inorganic powder via a chemical bond such as a covalent bond, a hydrogen bond, an ionic bond, or a van der Waals bond, or via physical adsorption. The surface treatment agent is not particularly limited as long as it is one that is commonly used in the field of cosmetics.

[0024] It is preferable that the inorganic powder (A) is substantially free of inorganic powder treated with a silicone compound such as dimethylpolysiloxane (silicone treatment). Specifically, the content of the silicone-treated inorganic powder is preferably 1% by mass or less, and more preferably 0.1% by mass or less, relative to 100% by mass of the content of the inorganic powder (A). Conventionally, silicone-treated inorganic powders have sometimes been used to improve the usability of water-in-oil emulsion cosmetics. The cosmetic of the present disclosure is excellent in usability even without the use of silicone-treated inorganic powder, and therefore the environmental impact caused by the use of silicone-treated inorganic powder can be reduced.

[0025] The content of the inorganic powder (A) is preferably 1 to 10% by mass, more preferably 3 to 9% by mass, and even more preferably 5 to 8% by mass, relative to 100% by mass of the cosmetic of the present disclosure. When the content of the inorganic powder (A) is 1% by mass or more, the desired effects are likely to be obtained. Furthermore, when the content of the inorganic powder (A) is 10% by mass or less, excellent base stability is likely to be obtained.

[0026] <Thickener (B)> The cosmetic preparation of the present disclosure includes (B) at least one thickener selected from the group consisting of an acrylamide-based polymer and an acrylic acid-based polymer, which does not have emulsifying ability. By blending the thickener (B) in addition to the inorganic powder (A), elasticity is synergistically improved, resulting in better usability.

[0027] In the present disclosure, an acrylamide-based polymer is a polymer having structural units derived from acrylamide or a derivative thereof. Examples of the acrylamide-based polymer include polyacrylamide, poly(acrylamide derivatives), copolymers of acrylamide and acrylamide derivatives, and copolymers of at least one monomer selected from the group consisting of acrylamide and acrylamide derivatives with other monomers (e.g., (meth)acrylic acid, (meth)acrylates, (meth)acrylic acid esters, vinylpyrrolidone, etc.).

[0028] Examples of acrylamide derivatives include N-substituted acrylamides and N,N-disubstituted acrylamides. Examples of N-substituted acrylamides include acryloyldimethyltaurine or a salt thereof. Examples of acryloyldimethyltaurine salts include alkali metal salts such as sodium salt, potassium salt, and lithium salt; salts with Group 2 elements such as calcium salt and magnesium salt; and ammonium salts. Examples of N,N-disubstituted acrylamides include dialkylacrylamides such as dimethylacrylamide.

[0029] As the acrylamide-based polymer, a polymer having a structural unit derived from an acrylamide derivative is preferred, a polymer containing at least one structural unit selected from the group consisting of a structural unit derived from dimethylacrylamide and a structural unit derived from acryloyldimethyltaurine or a salt thereof is more preferred, and a polymer containing a structural unit derived from acryloyldimethyltaurine or a salt thereof is even more preferred. Specific preferred examples of the acrylamide polymer include (dimethylacrylamide / sodium acryloyldimethyltaurate) crosspolymer, (sodium acrylate / sodium acryloyldimethyltaurate) copolymer, (ammonium acryloyldimethyltaurate / vinylpyrrolidone) copolymer, (sodium acryloyldimethyltaurate / hydroxyethyl acrylate) copolymer, (acryloyldimethyltaurate / sodium acrylate / dimethylacrylamide) crosspolymer, (sodium acryloyldimethyltaurate / acrylic acid / acrylamide / sodium acrylate) copolymer, (ammonium acryloyldimethyltaurate / dimethylacrylamide / lauryl methacrylate / laureth-4 methacrylate) crosspolymer, (ammonium acryloyldimethyltaurate / beheneth-25 methacrylate) crosspolymer, and (ammonium acryloyldimethyltaurate / steareth-25 methacrylate) crosspolymer.

[0030] In the present disclosure, the acrylic acid-based polymer refers to a polymer having structural units derived from acrylic acid, an acrylic acid salt, or an acrylic acid ester (excluding the above-mentioned acrylamide-based polymers). Examples of the acrylic acid-based polymer include polyacrylic acid, poly(acrylic acid salt), poly(acrylic acid ester), copolymers obtained from at least two monomers selected from the group consisting of acrylic acid, an acrylic acid salt, and an acrylic acid ester, and copolymers of at least one monomer selected from the group consisting of acrylic acid, an acrylic acid salt, and an acrylic acid ester with another monomer (e.g., vinylpyrrolidone).

[0031] Examples of acrylate salts include alkali metal salts such as sodium salts, potassium salts, and lithium salts; salts with Group 2 elements such as calcium salts and magnesium salts; and ammonium salts. Examples of acrylate esters include alkyl acrylates.

[0032] The acrylic acid-based polymer is preferably a polymer having a structural unit derived from acrylic acid. A specific example of a suitable acrylic acid-based polymer is a carboxyvinyl polymer (carbomer).

[0033] The content of the thickener (B) is preferably 0.01 to 1 mass%, more preferably 0.05 to 0.5 mass%, relative to 100 mass% of the cosmetic of the present disclosure. When the content of the thickener (B) is within the above range, excellent usability is likely to be obtained.

[0034] <Optional Components> In addition to the above-described essential components, the cosmetic preparation of the present disclosure may contain aqueous components and oily components commonly used in the field of cosmetics. Examples of such components include powder components other than the inorganic powder (A), non-volatile oils, coloring materials, pH adjusters, moisturizers, thickeners other than the thickener (B), surfactants, stabilizers, colorants, preservatives, antioxidants, UV absorbers, and fragrances.

[0035] The water content is, for example, 20 to 50% by mass, or 30 to 40% by mass, relative to 100% by mass of the cosmetic of the present disclosure.

[0036] The cosmetic preparation of the present disclosure may be substantially free of silicone elastomers such as dimethicone / vinyl dimethicone crosspolymer and dimethicone crosspolymer. Specifically, the content of silicone elastomer is preferably 1% by mass or less, and more preferably 0.1% by mass or less, relative to 100% by mass of the cosmetic preparation of the present disclosure. Conventionally, silicone elastomers have been included in cosmetics to improve the usability of water-in-oil emulsion cosmetics, but the cosmetic preparation of the present disclosure has excellent usability even without the inclusion of silicone elastomers.

[0037] Furthermore, the cosmetic preparation of the present disclosure may be substantially free of silicone. Specifically, the silicone content is preferably 1% by mass or less, and more preferably 0.1% by mass or less, relative to 100% by mass of the cosmetic preparation of the present disclosure. Conventionally, silicone has been included in cosmetics to improve the usability of water-in-oil emulsion cosmetics, but the cosmetic preparation of the present disclosure has excellent usability even without the inclusion of silicone.

[0038] The viscosity of the cosmetic preparation of the present disclosure at 30° C. is preferably 15,000 mPa·s or more, and more preferably 20,000 mPa·s or more and 35,000 mPa·s or less. The viscosity of the cosmetic preparation of the present disclosure at 30° C. is a value measured at 30° C. using a Brookfield viscometer (rotor No. 4, rotation speed 12 rpm).

[0039] The cosmetic preparation of the present disclosure can be produced by conventional methods, and the stirring method during emulsification, emulsification temperature, order of adding the oil phase and the water phase, and the rate of adding the phases may be appropriately set.

[0040] The cosmetic preparation of the present disclosure may be in the form of, for example, an emulsion or a cream.

[0041] The cosmetic preparation of the present disclosure is particularly suitable for makeup cosmetics such as foundations, etc. Therefore, the cosmetic preparation of the present disclosure can be provided in the form of a liquid foundation, a makeup base, a BB cream, a CC cream, a cushion foundation, etc.

[0042] The present disclosure will be described in more detail based on examples, but the present disclosure is not limited to these examples.

[0043] Examples 1 to 8 and Comparative Examples 1 to 6 Water-in-oil emulsion cosmetics having the compositions shown in Tables 1 and 2 were prepared as follows. The components listed in Group A were mixed uniformly to obtain Mixture A. The components listed in Group B were added to Mixture A and uniformly dispersed using a homomixer to obtain Dispersion AB. The components listed in Group C were mixed uniformly to obtain Mixture C. Mixture C was added to Dispersion AB while stirring using a homomixer, and emulsified until a single phase was obtained. The emulsion was degassed to obtain a water-in-oil emulsion cosmetic.

[0044] The viscosity of the prepared cosmetic materials was measured. The prepared cosmetic materials were also evaluated as follows. The results are shown in Tables 1 and 2.

[0045] <Base Stability> The prepared cosmetic was filled into a 50 mL jar (made of resin) and left to stand at room temperature, 50°C, for 4 weeks. Thereafter, the emulsified state was examined with the naked eye and a microscope, and evaluated based on the following evaluation criteria. (Evaluation criteria) A: No phase separation at all, and stable with no change in either the emulsified particles or viscosity B: No phase separation, but some of the emulsified particles are broken or the viscosity has decreased C: Phase separation has occurred

[0046] <Usability> The prepared cosmetic was applied at a concentration of 2 mg / cm to the inside of the forearm of expert panelists (10 women). ２The subjects were asked to respond to the feel (elasticity and fit) of the cosmetic when spreading it over a specified area, and the elasticity and fit were evaluated based on the following evaluation criteria. In the present disclosure, "elasticity" refers to the feeling that the cosmetic does not become watery under the pressure of application and has a moderate elasticity when spreading it. Furthermore, "fit" refers to the feeling that the cosmetic blends well with the skin when spreading it. (Evaluation criteria (elasticity)) A: 9 or more people answered that there was an elasticity B: 6 to 8 people answered that there was an elasticity C: 5 or less people answered that there was an elasticity (Evaluation criteria (fit)) A: 9 or more people answered that there was an elasticity B: 6 to 8 people answered that there was an elasticity C: 5 or less people answered that there was an elasticity

[0047]

[0048] ＊１ : Vegelight C912LC (manufactured by Grant Industries, Inc.) ＊２ : PolyAquol VO4 (manufactured by Innovacos) ＊３ : Surface treatment with polyglyceryl-2 tetraisostearate ＊４ : CHIFFONSIL 5 (manufactured by JGC Catalysts and Chemicals, spherical non-porous silica, average particle size: 4 to 6 μm, specific surface area: 2.2 m) ２ / g, oil absorption: 20mL / 100g) ＊５ COVABEAD CRYSTAL (manufactured by Sensient Cosmetic Technologies, spherical solid borosilicate, average particle size: 10 μm, specific surface area: 0.5 m) ２ / g, oil absorption: 30mL / 100g)) ＊６ : SIMULGEL EG (manufactured by SEPPIC, (meth)acrylamide polymer) ＊７ ARISTOFLEX AVC (manufactured by Clariant Japan, (meth)acrylamide polymer) ＊８ Carbopol 980 (manufactured by Lubrizol Japan, (meth)acrylic acid polymer)

[0049] ＊９ : Sunsphere L-51S (AGC Si-Tech Co., Ltd., porous silica, average particle size: 8-10 μm, specific surface area: 301 m ２ / g, oil absorption: 161mL / 100g) ＊１０ : ADEKA NOL GT-930 (manufactured by ADEKA Corporation)

[0050] As shown in Tables 1 and 2, the water-in-oil emulsion cosmetics of the examples containing the specified spherical solid inorganic powder (A) and the specified thickener (B) are found to be excellent in base stability and usability.

Claims

1. A water-in-oil emulsion cosmetic comprising: (A) at least one type of spherical inorganic powder selected from the group consisting of non-porous silica particles and solid borosilicate particles; and (B) at least one type of thickener not having emulsifying ability selected from the group consisting of acrylamide-based polymers and acrylic acid-based polymers.

2. The specific surface area of ​​the spherical inorganic powder (A) is 100 m ２ The cosmetic according to claim 1, wherein the viscosity is 1 / g or less.

3. The cosmetic according to claim 1, wherein the oil absorption of the spherical inorganic powder (A) is 50 mL / 100 g or less.

4. The cosmetic according to claim 1, wherein the content of the spherical inorganic powder (A) is 1 to 10% by mass.

5. The cosmetic preparation according to claim 1, wherein the content of the thickener (B) is 0.05 to 0.5% by mass.

6. The cosmetic according to any one of claims 1 to 5, wherein the viscosity of the cosmetic is 15,000 mPa·s or more.

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