JP2021001117A - W/o type pickering emulsion and cosmetic containing the same - Google Patents

Abstract

To provide a design technique of cosmetics having low secondary adhesiveness.SOLUTION: W/O type Pickering emulsion contains a water phase, an oil phase and hydrophobized powder, and contains volatile oil agent by 40 mass% or more with respect to the total amount of oil agent contained in the oil phase.SELECTED DRAWING: Figure 1

Description

The present invention relates to a W / O type pickering emulsion and a cosmetic containing the same.

Conventionally, there has been a problem of so-called "secondary adhesion" in which cosmetics adhere to clothes, cups, etc., or are removed by physical contact such as rubbing by hand.

When secondary adhesion occurs, the makeup breaks down, and it becomes necessary to remake the makeup frequently. In addition, there is a problem that it is difficult to remove cosmetics when they adhere to clothing, which is annoying to many cosmetic users.

As a cosmetic design for preventing secondary adhesion, a method including a polymer emulsion containing a film-forming agent containing a crosslinkable polymer containing a reactive silyl group is known (Patent Documents 1 and 2).

JP-A-2002-327019 Japanese Unexamined Patent Publication No. 2003-20314

However, even with the method using such a film forming agent, secondary adhesion could not be sufficiently prevented.

The cause of the secondary adhesion is that the decorative film is highly adherent, and a part of the decorative film is peeled off by applying a force to the surface (air interface) of the decorative film.

Therefore, as a means for reducing the secondary adhesion, it is conceivable to reduce the adhesiveness of the entire cosmetic film, but in this case, the adhesiveness to the skin is also reduced, and as a result, the secondary adhesion may occur.

Therefore, an object of the present invention is to provide a design technique for cosmetics having low secondary adhesiveness.

As a result of diligent research, the present inventors have found that an emulsion (pickling emulsion) containing a specific oil agent in a specific compounding ratio and emulsified by powder has excellent adhesion to the skin and secondary adhesion. We found that the property was low and completed the present invention.

That is, the present invention that solves the above problems
It is a W / O type pickering emulsion containing an aqueous phase, an oil phase, and a hydrophobic powder, and containing 40% by mass or more of a volatile oil agent with respect to the total amount of the oil agent contained in the oil phase.
The pickering emulsion of the present invention has an extremely high effect of preventing secondary adhesion.

In a preferred embodiment of the present invention, the content of the aqueous phase is 5% by mass or more with respect to the total amount of the W / O type pickering emulsion.
The W / O type pickering emulsion of the present invention having an aqueous phase content of a specific amount or more has an extremely high effect of preventing secondary adhesion.

In a preferred embodiment of the present invention, the hydrophobic powder has an M value of 10 or more.
By using a hydrophobic powder having an M value equal to or higher than the above value, a higher secondary adhesion prevention effect can be obtained.

In a preferred embodiment of the present invention, the hydrophobized powder has a primary particle size of 200 nm or less.

In a preferred embodiment of the present invention, the hydrophobized powder is a powder coated with an acrylic resin and / or an organosilicon compound.

In a preferred embodiment of the present invention, the volatile oil is a hydrocarbon oil and / or a volatile silicone oil.

Further, the present invention that solves the above-mentioned problems is a cosmetic containing the above-mentioned W / O type pickering emulsion.

In a preferred embodiment of the invention, the cosmetic is a foundation or sunscreen.

In addition, the present invention that solves the above problems
The process of preparing the aqueous phase and
Equipped with a process to prepare the oil phase
The oil phase contains an oil agent and a hydrophobic powder, and the oil agent contains 40% by mass or more of a volatile oil agent with respect to the total amount of the oil agent.
A method for producing a W / O type pickering emulsion, which comprises a step of mixing the aqueous phase and the oil phase to prepare an emulsion.

Further, the present inventors further studied the above-mentioned pickering emulsion or a cosmetic film obtained by applying a cosmetic, and found that the makeup has excellent adhesion to the skin and low secondary adhesion. It was found that the membrane has a porous structure in which the hollow space surrounded by the fine particles remains as it is after the emulsified droplets inside volatilize. That is, by observing the structure of the cosmetic film, the cosmetic film having the above-mentioned properties can be identified.

That is, the present invention that solves the above problems
It is an evaluation method of cosmetic film
The step of observing the surface or cross section of the cosmetic film obtained by applying the cosmetic containing the W / O type pickering emulsion and the effect of suppressing secondary adhesion when a porous structure is observed in the cosmetic film. It is a method for evaluating a cosmetic film, which comprises a step of evaluating the cosmetic film to have.

The W / O type pickering emulsion of the present invention and cosmetics containing the same have an extremely high effect of suppressing secondary adhesion. Further, according to the method for evaluating a cosmetic film of the present invention, it is possible to identify a cosmetic product having a high effect of suppressing secondary adhesion.

It is a drawing substitute photograph which shows the result of the secondary adhesion test. It is an SEM image which observed the surface of the decorative film of an Example and a comparative example. It is a CT image which observed the cross section of the decorative film of an Example. It is a graph which shows the secondary adhesion amount with respect to the drying time in an Example and a comparative example.

<1> W / O-type pickering emulsion The present invention is a W / O-type pickering emulsion in which an aqueous phase and an oil phase are emulsified with a hydrophobic powder. Hereinafter, each configuration will be described in detail.

(1) Oil phase component The pickering emulsion of the present invention contains an oil agent as an oil phase component.
The content of the oil agent is preferably 10 to 80% by mass, more preferably 20 to 70% by mass, still more preferably 20 to 50% by mass, and particularly preferably 20% by mass, based on the total amount of the pickering emulsion. ~ 40% by mass.

As the oil agent, liquid fats and oils, solid fats and oils, waxes, hydrocarbon oils, higher fatty acids, higher alcohols, ester oils, silicone oils and the like can be contained.

Liquid fats and oils include, for example, avocado oil, camellia oil, turtle oil, macadamia nut oil, corn oil, mink oil, olive oil, rapeseed oil, egg yolk oil, sesame oil, persic oil, wheat germ oil, southern ka oil, castor oil, flaxseed oil. , Saflower oil, cotton seed oil, eno oil, meadowfoam oil, soybean oil, peanut oil, tea seed oil, kaya oil, rice bran oil, cinnamon oil, Japanese millet oil, jojoba oil, germ oil, triglycerin, glycerin trioctanoate, Examples thereof include glycerin triisopalmitate.

Solid fats and oils include cacao fat, coconut oil, horse fat, hardened coconut oil, palm oil, beef tallow, sheep fat, hardened beef tallow, palm kernel oil, lard, beef tallow, mokuro kernel oil, hardened fat, and beef tallow. , Mokuro, hardened castor oil and the like.

Examples of waxes include beeswax, candelilla wax, cotton wax, carnauba wax, baby wax, squid wax, whale wax, montan wax, nukarou, lanolin, capoc wax, lanolin acetate, liquid lanolin, sugar cane, lanolin fatty acid isopropyl, hexyl laurate, reduced lanolin, jojo. Examples thereof include barrow, hard lanolin, cellac wax, POE lanolin alcohol ether, POE lanolin alcohol acetate, POE cholesterol ether, lanolin fatty acid polyethylene glycol, POE hydrogenated lanolin alcohol ether and the like.

Examples of the hydrocarbon oil include liquid paraffin, ozokerite, pristane, paraffin, selecin, squalene, petrolatum, microcrystalline wax and the like.

Examples of higher fatty acids include lauric acid, myristic acid, palmitic acid, stearic acid, behenic (behenic acid) acid, 12-hydroxystearic acid, undecylenic acid, and tall acid.

Examples of the higher alcohol include cetyl alcohol, stearyl alcohol, behenyl alcohol, batyl alcohol, myristyl alcohol, and cetostearyl alcohol.

As ester oils, isopropyl myristate, cetyl octanoate, octyldodecyl myristate, isopropyl palmitate, butyl stearate, hexyl laurate, myristyl myristate, decyl oleate, hexyldecyl dimethyloctanoate, cetyl lactate, myristyl lactate, Lanolin acetate, isocetyl stearate, isocetyl isostearate, sucrose stearate, sucrose oleate, cholesteryl 12-hydroxystearyl, ethylene glycol di-2-ethylhexylate, dipentaerythritol fatty acid ester, N-alkyl glycol monoisostearate, dicaprine Neopentyl glycol acid acid, diisostearyl malate, glycerin di-2-heptyl undecanoate, trimethylol propane tri-2-ethylhexylate, trimethylolpropane triisostearate, pentanerythritol tetra-2-ethylhexylate, tri-2- Glycerin ethylhexylate, trimethylolpropane triisostearate, cetyl2-ethylhexanoate, 2-ethylhexyl palmitate, glycerin trimyristate, glyceride tri-2-heptylundecanoic acid, methyl ester of castor oil fatty acid, oleic acid oil, seto Stearyl alcohol, acetoglyceride, 2-heptyl undecyl palmitate, cetyl palmitate, diisobutyl adipate, N-lauroyl-L-glutamic acid-2-octyldodecyl ester, di-2-heptyl undecyl adipate, ethyl laurate, Di-2-ethylhexyl sebatate, 2-hexyldecyl myristate, 2-hexyldecyl palmitate, 2-hexyldecyl adipate, diisopropyl sebatate, 2-ethylhexyl succinate, ethyl acetate, butyl acetate, amyl acetate, citric acid Examples thereof include triethyl.

Silicone oils include chain siloxanes such as dimethylpolysiloxane, methylphenylpolysiloxane, methylhydrogenpolysiloxane, diphenyltrimethicone, and diphenylsiloxyphenyltrimethicone, pentasiloxane, decamethylpolysiloxane, dodecamethylpolysiloxane, and tetra. Examples thereof include cyclic siloxanes such as methyltetrahydrogenpolysiloxane.

The pickering emulsion of the present invention contains 40% by mass or more of a volatile oil agent with respect to the total amount of the oil agent.
Preferred examples of the volatile oil agent include volatile silicone oil, volatile hydrocarbon oil, volatile ester oil, volatile natural animal and vegetable oil, and volatile fluorine oil, and volatile silicone oil and volatile hydrocarbon oil are included. More preferred.

Volatile silicone oils include dimethylpolysiloxane, methyltrimethicone, tris (trimethylsilyl) methylsilane, tetrakis (trimethylsilyl) silane, hexacyclotrisiloxane, octamethyltetracyclosiloxane, cyclopentasiloxane, decamethylcyclopentasiloxane, dodecamethyl. Examples thereof include cyclohexasiloxane and tetradecamethylcycloheptasiloxane.

Examples of the volatile hydrocarbon oil include decane, undecane, dodecane, tridecane, isooctane, isodecan, isododecane, isohexadecane, cyclodecane and cyclododecane.

The pickering emulsion of the present invention preferably contains both a volatile oil agent and a non-volatile oil agent.
The content of the volatile oil agent with respect to the total amount of the oil agent is preferably 42% by mass or more, and more preferably 45% by mass or more.
The upper limit of the volatile oil agent with respect to the total amount of the oil agent is preferably 80% by mass or less, more preferably 65% by mass or less, further preferably 60% by mass or less, and particularly preferably 55% by mass or less, which is the most. It is preferably 50% by mass or less.

(2) Aqueous phase component The content of water in the aqueous phase of the pickering emulsion of the present invention is preferably 5% by mass or more, more preferably 25% by mass or more, and further preferably 35% by mass or more. , Especially preferably 40% by mass or more, and most preferably 45% by mass or more.
By setting the water content in such a range, after the emulsified droplets in the cosmetic film volatilize, the occupied area of the porous structure in the cosmetic film becomes large, and the secondary adhesion effect is further enhanced.

The water content is preferably 90% by mass or less, more preferably 80% by mass or less, further preferably 70% by mass or less, particularly preferably 60% by mass or less, and most preferably. It is 50% by mass or less.
The water content is preferably 1 to 60% by mass, more preferably 5 to 50% by mass or more, further preferably 20 to 50% by mass, and particularly preferably 30 to 50% by mass. Most preferably, it is 40 to 50% by mass or more.

The water content is preferably 0.05 to 2 parts by mass, more preferably 0.1 to 2 parts by mass, and further preferably 1 part by mass with respect to 1 part by mass of the total amount of the oil agent described in (1) above. It is 0.4 to 2 parts by mass, particularly preferably 0.6 to 1.5 parts by mass, and particularly preferably 0.8 to 1.2 parts by mass.
The water content is preferably 0.05 to 5 parts by mass, more preferably 0.5 to 4 parts by mass, and further preferably 1 to 3 parts by mass with respect to 1 part by mass of the volatile oil agent. Parts, particularly preferably 1.0 to 2.5 parts by mass,

The lower limit of the content of the total amount of the aqueous phase with respect to the total amount of the picker rig emulsion is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 30% by mass or more, and particularly preferably 40. It is mass% or more, and most preferably 45 mass% or more.
The upper limit is preferably 90% by mass or less, more preferably 80% by mass or less, further preferably 70% by mass or less, particularly preferably 60% by mass or less, and most preferably 55% by mass or less. Is.

The content of the total amount of the aqueous phase with respect to the total amount of the pickering emulsion is preferably 5 to 70% by mass, more preferably 20 to 60% by mass, still more preferably 30 to 60% by mass, and particularly preferably. Is 40 to 60% by mass, most preferably 45 to 55% by mass.

The aqueous phase in the pickering emulsion of the present invention may contain components usually used in cosmetics without particular limitation, but for example, it is preferable to contain the following components.
Examples of polyols include polyethylene glycol, glycerin, 1,3-butylene glycol, erythritol, sorbitol, xylitol, martitol, propylene glycol, dipropylene glycol, diglycerin, isoprene glycol, 1,2-pentanediol, 2,4-he. Xylene glycol, 1,2-hexanediol, 1,2-octanediol and the like can be mentioned, and among them, glycerin, 1,3-butylene glycol and sorbitol are preferably mentioned. These contents are preferably 0.5 to 20% by mass, and more preferably 3 to 10% by mass of the entire pickering emulsion. Moreover, these contents are preferably 3 to 15% by mass, more preferably 5 to 10% by mass of the aqueous phase.

In addition, the pickering emulsion of the present invention may contain a thickener. Thickeners include xanthan gum, gellan gum, guagam, quince seed, carrageenan, galactan, arabic gum, pectin, mannan, starch, curdlan, methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, methyl hydroxypropyl cellulose, chondroitin sulfate, dermatan sulfate, Glycogen, heparan sulfate, hyaluronic acid, sodium hyaluronate, traganth gum, keratane sulfate, chondroitin, mucoitin sulfate, hydroxyethyl guagam, carboxymethyl guagam, dextran, keratosulfate, locust bean gum, succinoglucan, carrageenic acid, chitin, chitosan, Examples thereof include carboxymethyl chitin, agar, polyvinyl alcohol, polyvinylpyrrolidone, carboxyvinyl polymer, sodium polyacrylate, polyethylene glycol, sodium acrylate graft starch, stearoxyhydroxypropylmethyl cellulose, bentonite and the like. These contents are preferably 0.05 to 5% by mass, more preferably 0.1 to 1% by mass of the entire pickering emulsion. The content of these is preferably 0.1 to 3% by mass, more preferably 0.3 to 1% by mass in the aqueous phase.

(3) Hydrophobized powder Examples of the hydrophobized powder include inorganic powders such as silica, titanium dioxide, tin oxide, viscous minerals, aluminum oxide, nanoparticulate precipitated calcium carbonate, coal, magnesium oxide, and magnesium trisilicate. In addition, any of organic powders such as ethyl cellulose, crystalline fatty alcohol and fatty acid, polystyrene, and resin particles such as polymethyl methacrylate (PMMA) can be used, and the surface of these powders is hydrophobized as necessary. Can be used.
Preferably, a partially hydrophobized powder having a partially hydrophobized surface of these powders is used.

Examples of the hydrophobizing treatment include a method of treating the powder with a hydrophobizing agent such as an organosilicon compound, silicone, hydrocarbon oil, fatty acid, fatty acid amide, fatty acid ester, higher alcohol, and polyoxyalkylene compound.
Particularly preferably, the powder is treated using an organosilicon compound or silicone as a hydrophobizing agent.

Organosilicon compounds include hexamethyldisilazane, monomethylsilane, dimethylsilane, trimethylsilane, trimethylethoxysilane, isobutyltrimethoxysilane, trimethylchlorosilane, dimethyldichlorosilane, methyltrichlorosilane, dimethylethoxysilane, dimethyldimethoxysilane, and diphenyldi. Examples thereof include ethoxysilane, hexamethyldisiloxane, and palmitylsilane. These can be used in one or a mixture of two or more.

Examples of the silicone include dimethyl silicone, methylphenyl silicone, α-methylstyrene modified silicone, chlorphenyl silicone, fluorine-modified silicone and the like.

The lower limit of the M value of the hydrophobized powder in the pickering emulsion of the present invention can be preferably 10 or more, more preferably 15 or more, and particularly preferably 20 or more.

The M value is a value indicating the degree of hydrophobicity of the fine particles, and it can be said that the higher the M value, the higher the hydrophobicity. The M value is the minimum necessary for uniformly dispersing the measurement sample in a mixed solution of water and methanol. It is expressed by the volume ratio of the amount of methanol, and can be determined by the following method.

[Calculation method of M value]
0.2 g of the measurement sample (hydrophobicized powder fine particles) is added to 50 mL of water in a beaker having a volume of 250 mL, and then methanol is gradually added dropwise from the burette. At this time, the solution in the beaker is constantly stirred with a magnetic stirrer, and the end point is when the entire amount of the measurement sample is uniformly suspended in the solution. The volume percentage of methanol in the water / methanol mixed solution in the beaker at this end point is the M value.
The M value of the hydrophobized powder can be adjusted by the hydrophobization rate. The M value or the hydrophobization rate can be adjusted by appropriately setting the mixing ratio of the powder and the hydrophobizing agent and the treatment time.

The average primary particle size of the hydrophobized powder is preferably 200 nm or less, more preferably 100 nm or less, still more preferably 50 nm or less, more preferably 30 nm or less, and particularly preferably 15 nm or less.
By setting the particle size of the hydrophobized powder within the above range, the emulsified particles can be adjusted to be small, and the stability of the preparation is improved.

In the present invention, the average primary particle diameter is not particularly limited and means the diameter of the primary particles measured by a method generally used for particles. Specifically, from a transmitted electron micrograph, It is obtained as the arithmetic mean of the major axis and the minor axis of the particles.

The content of the hydrophobized powder with respect to the total amount of the pickering emulsion of the present invention is preferably 0.3 to 5% by mass, more preferably 0.4 to 4% by mass, still more preferably 0.5 to 3% by mass. It is particularly preferably 0.7 to 2.5% by mass, and most preferably 1 to 2% by mass.

The content of the hydrophobized powder is preferably 0.1 to 1 part by mass, more preferably 0.2 to 1 part by mass, and further preferably 0.3 to 1 part by mass with respect to 10 parts by mass of the oil agent. , Particularly preferably 0.4 to 1 part by mass, and most preferably 0.5 to 0.8 part by mass.

The content of the hydrophobized powder is preferably 0.1 to 3 parts by mass, more preferably 0.1 to 1 part by mass, still more preferably 0.1 to 0.5 parts by mass with respect to 10 parts by mass of the water. It is by mass, particularly preferably 0.2 to 0.3 parts by mass.

(4) Pickering Emulsion The pickering emulsion of the present invention is a water-in-oil (W / O type) emulsion. In the pickering emulsion of the present invention, in addition to the above components, any component usually used in cosmetics can be contained within a range that does not impair the effects of the invention. Such optional components include, for example, anionic surfactants such as fatty acid soap (sodium laurate, sodium palmitate, etc.), potassium lauryl sulfate, triethanolamine ether alkyl sulfate, stearyltrimethylammonium chloride, benzalconium chloride, lauryl. Cationic surfactants such as amine oxide, imidazoline-based amphoteric surfactants (2-cocoyl-2-imidazolinium hydroxide-1-carboxyethyroxy disodium salt, etc.), betaine-based surfactants (alkylbetaine, amide, etc.) (Betaine, sulfobetaine, etc.), amphoteric surfactants such as acylmethyltaurine, sorbitan fatty acid esters (sorbitan monostearate, sorbitan sesquioleate, etc.), glycerin fatty acids (glycerin monostearate, etc.), propylene glycol fatty acid esters Classes (propylene glycol monostearate, etc.), hardened castor oil derivative, glycerin alkyl ether, POE sorbitan fatty acid esters (POE sorbitan monooleate, polyoxyethylene sorbitan monostearate, etc.), POE sorbit fatty acid esters (POE-sorbit) Monolaurate, etc.), POE glycerin fatty acid esters (POE-glycerin monoisostearate, etc.), POE fatty acid esters (polyethylene glycol monoolate, POE distearate, etc.), POE alkyl ethers (POE2-octyldodecyl ether, etc.), POE alkylphenyl ethers (POE nonylphenyl ethers, etc.), pluronic types, POE / POP alkyl ethers (POE / POP2-decyltetradecyl ethers, etc.), silicone ethers such as triethoxycaprylylsilane, tetronics, Nonionic surfactants such as POE castor oil / hardened castor oil derivative (POE castor oil, POE cured castor oil, etc.), sucrose fatty acid ester, alkyl glucoside, moisturizing ingredients such as sodium pyrrolidone carboxylate, lactic acid, sodium lactate, etc. Powders such as mica, talc, kaolin, synthetic mica, calcium carbonate, magnesium carbonate, silicic acid anhydride (silica), aluminum hydroxide, iron oxide, titanium oxide, aluminum oxide, barium sulfate, etc., which may be surface-treated. Kind, may be surface-treated, cobalt oxide, ultramarine, dark blue, zinc oxide inorganic pigments, may be surface-treated, iron oxide titanium dioxide sintered body, etc. Composite pigments, pearl agents such as mica titanium, fish phosphorus foil, bismuth oxychloride, which may be surface-treated, red 202, red 228, red 226, yellow 4, which may be raked. Blue No. 404, Yellow No. 5, Red No. 505, Red No. 230, Red No. 223, Orange No. 201, Red No. 213, Yellow No. 204, Yellow No. 203, Blue No. 1, Green No. 201, Purple No. 201, Red 204 Organic pigments such as No., polyethylene powder, polymethyl methacrylate, nylon powder, organic powders such as organopolysiloxane elastomer, lower alcohols such as ethanol and isopropanol, vitamin A or its derivatives, vitamin B6 hydrochloride, vitamins B6 tripalmitate, vitamin B6 dioctanoate, vitamin B2 or its derivatives, vitamin Bs such as vitamin B12, vitamin B15 or its derivatives, vitamin Es such as α-tocopherol, β-tocopherol, γ-tocopherol, vitamin E acetate, Vitamins such as vitamin D, vitamin H, pantothenic acid, pantetin, pyroquinolinquinone, paraaminobenzoic acid, paraaminobenzoic acid monoglycerin ester, N, N-dipropoxyparaaminobenzoic acid ethyl ester, N, N-diethoxyparaamino Benzoic acid derivatives such as benzoic acid ethyl ester, N, N-dimethylparaaminobenzoic acid ethyl ester, N, N-dimethylparaaminobenzoic acid butyl ester, N, N-dimethylparaaminobenzoic acid ethyl ester, diethylaminohydroxybenzoyl hexyl benzoate; Anthranic acid derivatives such as homomentyl-N-acetylanthranilate; salicylic acid and sodium salts thereof, amyl salicylate, menthyl salicylate, homomentyl salicylate, octyl salicylate, phenyl salicylate, benzyl salicylate, p-isopropanol phenyl salicylate and other salicylic acid derivatives; Synnamate, Ethyl-4-isopropylsinnamate, Methyl-2,5-diisopropylsinnamate, Ethyl-2,4-diisopropylsinnamate, Methyl-2,4-diisopropylsinnamate, propyl-p-methoxycinnamate, isopropyl -P-methoxycinnamate, isoamyl-p-methoxycinnamate, 2-ethylhexyl p-methoxycinnamate (ethylhexyl methoxycinnamate, octyl paramethoxycinnamate), 2-ethoxy Ethyl-p-methoxycinnamate (synoxate), cyclohexyl-p-methoxycinnamate, ethyl-α-cyano-β-phenylcinnamate, 2-ethylhexyl 2-cyano-3,3-diphenylacrylate (octocrylene), glyceryl Silica skin acid derivatives such as mono-2-ethylhexanoyl-diparamethoxycinnamate, ferulic acid and derivatives thereof; 2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'- Dihydroxy-4,4'-dimethoxybenzophenone, 2,2', 4,4'-tetrahydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone (oxybenzophenone-3), 2-hydroxy-4-methoxy-4'-methyl Benzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonate, 4-phenylbenzophenone, 2-ethylhexyl-4'-phenyl-benzophenone-2-carboxylate, 2-hydroxy-4-n-octoxybenzophenone, Benzophenone derivatives such as 4-hydroxy-3-carboxybenzophenone; 3- (4'-methylbenzylene) -d, l-camfer, 3-benziliden-d, l-campar; 2-phenyl-5-methylbenzoxazole; 2,2'-Hydroxy-5-methylphenylbenzotriazole; 2- (2'-hydroxy-5'-t-octylphenyl) benzotriazole; 2- (2'-hydroxy-5'-methylphenylbenzotriazole; dibenzalazine) Dianisoylmethane; 5- (3,3-dimethyl-2-norbornylidene) -3-pentan-2-one; dibenzoylmethane derivatives such as 4-t-butylmethoxydibenzoylmethane; octylriazone; urocanic acid and Urocanic acid derivatives such as ethyl urocanate; 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 1- (3,4-dimethoxyphenyl) -4,4-dimethyl-1,3-pentandione, Hydantin derivatives such as 2-ethylhexyl dimethoxybenzidenedioxoimidazolidine propionate; phenylbenzimidazole sulfonic acid, terephthalilidene dicanfursulfonic acid, drometrizole trisiloxane, methyl anthranilate, bisethylhexyloxyphenol methoxyphenyltriazine, Rutin and its derivatives, orizanol and its derivatives An ultraviolet absorber such as a derivative of the above can be preferably exemplified.

As described above, the pickering emulsion of the present invention may use a surfactant, but its content is preferably as small as possible. The content of the surfactant is preferably 5% by mass or less, more preferably 1% by mass or less, still more preferably 0.1% by mass or less, and particularly preferably 0% by mass.

The pickering emulsion of the present invention is suitable as an external preparation for skin because of its high effect of suppressing secondary adhesion.
Of these, it is preferably used in cosmetics, and is preferably used as a sunscreen, a makeup base, a foundation, and the like. As the foundation, it is particularly preferable to use it as a liquid foundation.

The pickering emulsion of the present invention can be produced by the following production method.
First, a step of preparing an aqueous phase containing the above-mentioned optional components as appropriate and a step of preparing the above-mentioned oil phase are provided.
The oil phase contains an oil agent and a hydrophobic powder, and the oil agent contains 40% by mass or more of a volatile oil agent with respect to the total amount of the oil agent.

Next, by mixing the aqueous phase and the oil phase, emulsification of the aqueous phase and the oil phase with the hydrophobic powder occurs, and the W / O type pickering emulsion of the present invention is produced.

In the state where the pickering emulsion of the present invention and the cosmetic containing the same are stored in a container, the powder is present at the interface between the aqueous phase and the oil phase, and the emulsified state is maintained.

The present inventors have confirmed that when this is applied to the skin, after the emulsified droplets volatilize, a hollow space surrounded by fine particles remains as it is, resulting in a porous structure.

From this finding, it is considered that the excellent effect of suppressing secondary adhesion in the pickering emulsion and the cosmetic of the present invention is due to the porous structure after the volatilization of the emulsion droplets.

<2> Evaluation Method of Cosmetic Film The present invention is an evaluation method for a cosmetic film, which was completed based on the above findings.
The method for evaluating a cosmetic film of the present invention includes a step of observing the surface or cross section of the cosmetic film obtained by applying a cosmetic containing a W / O type pickering emulsion.
Observation of the surface of the cosmetic film can be performed using, for example, a microscope. As the microscope, an optical microscope, an electron microscope, or the like can be used, and it is preferable to use a scanning electron microscope (SEM).
Observation of the surface of the cosmetic film can be performed using, for example, an X-ray CT apparatus.

Next, the method for evaluating a decorative film of the present invention includes a step of evaluating a decorative film having a secondary adhesion suppressing effect when a porous structure is observed in the decorative film.
As described above, it is presumed that the presence of the porous structure of the decorative film having a porous structure can suppress the secondary adhesion because the secondary adhesion destination such as clothes and the liquid component in the decorative film do not come into direct contact with each other. To.
Further, since the decorative film having a porous structure has high structural strength due to the porous structure, it is presumed that the decorative film is resistant to rubbing.

The evaluation method of the present invention preferably has a more excellent secondary adhesion suppression as a decorative film having a occupancy rate of less than 50% when the occupancy rate of the porous structure with respect to the thickness of the decorative film exceeds 50%. It is provided with an evaluation step of evaluating the cosmetic film as having an effect.
The reference value of the occupancy rate in the evaluation is preferably 55%, more preferably 70%, further preferably 75%, particularly preferably 80%, and most preferably 95%.
The evaluation step is based on the finding that the larger the occupancy ratio of the porous structure with respect to the thickness of the decorative film, the higher the effect of suppressing secondary adhesion.

The occupancy rate can be derived by calculation.
First, the decorative film is observed, and when a porous structure is confirmed, the particle size of the porous structure is measured. The particle size of this porous structure can be assumed to be the particle size of water droplets in the W / O emulsion. It is possible to calculate the occupancy rate of the porous structure with respect to the thickness of the decorative film when powders having an arbitrary particle size and having emulsifying ability are adsorbed and stacked.

<Test Example 1> Preparation of emulsion The aqueous phase and oil phase shown in Table 1 below were prepared, mixed and emulsified to produce a foundation.
The "powder" in Table 1 is a powder having no emulsifying ability, and the "silylated silica" in the "emulsifier" column is the "hydrophobicized powder" in the present specification. In this test, silylated silyl having an average primary particle diameter of 12 nm and an M value of 10 or more was used.
Further, "W / O (P)" in Table 1 means a W / O type pickering emulsion, and "W / O" means a W / O type emulsion that is not a pickering emulsion.

<Test Example 2> Secondary Adhesiveness Evaluation Test The following tests were carried out on Example 1, Comparative Example 1 and Comparative Example 2 to evaluate the secondary adhesiveness.
The foundation adjusted in Test Example 1 was applied to 5 cm × 5 cm artificial leather at 2 mg / cm ² .
After drying for 10 minutes, a 5 cm × 5 cm white cloth (100% cotton) was allowed to stand from above so as to cover the foundation applied to the artificial leather.
Further, a weight of 300 g was placed on it, and the white cloth was pulled out in that state.

The foundation adhering to the white cloth was visually confirmed. In addition, a white cloth was photographed, and the part where the foundation was attached and the part where the foundation was not attached were binarized, and the area ratio of these was obtained. The results are shown in Table 1 and FIG.

From the results of Table 1 and FIG. 1, a pickling emulsion containing an aqueous phase, an oil phase, and a hydrophobic powder, and containing 40% by mass or more of a volatile oil agent with respect to the total amount of the oil agent contained in the oil phase. It can be seen that the secondary adhesiveness of Examples 1 to 5 is extremely low.

On the other hand, Comparative Example 1 (corresponding to a conventional liquid foundation) emulsified with a silicone-based surfactant regardless of powder, and Comparative Example 2 using only an oil agent as a dispersion medium without containing water are secondary. Adhesion was high.

Further, Comparative Example 2 in which water was not contained and only an oil agent was used as a dispersion medium had excellent adhesion to the skin and was easy to dry, but had high secondary adhesion. From this result, it can be seen that the water-in-oil emulsification system is one of the factors that reduce the secondary adhesion.

Further, Comparative Example 3 in which the volatile oil agent was less than 40% by mass in the total amount of the oil agent had high secondary adhesion.
From this result, it was found that a composition having excellent secondary adhesiveness can be obtained by containing at least 40% by mass or more of the volatile oil agent in the total amount of the oil agent.

<Test Example 3> Observation of Membrane Structure A foundation was prepared according to the formulation shown in Table 2 below (Example 6, Comparative Example 4, Comparative Example 5).
The prepared foundation was applied onto artificial leather at a rate of 0.2 mg / cm ² , dried for 30 minutes, and then surface-observed using SEM.
In the foundation of Example 2, a cross-sectional observation was further performed using an X-ray CT apparatus. The results are shown in FIGS. 2 and 3.

<Test Example 4> Change in secondary adhesion amount for each drying time In the secondary adhesion evaluation test of Test Example 2, the drying time was changed to 1 minute, 3 minutes, 5 minutes, 10 minutes, and 15 minutes. The secondary adhesiveness of Example 6, Comparative Example 4, and Comparative Example 5 was evaluated. Each verification was carried out at N = 3, and the average value was calculated. The results are shown in FIG.

Example 6 was excellent in suppressing the secondary adhesion of the skin, and Comparative Examples 4 and 5 could not confirm the effect of suppressing the secondary adhesion. This result is in good agreement with the result of Test Example 2.
From FIGS. 2 and 3, it was possible to confirm that the cosmetic film obtained from the foundation of Example 6 had a porous structure having a cavity of about 5 μm, which was presumed to have been formed after the emulsified droplets had evaporated. In the foundation using a surfactant (Comparative Example 4) and the foundation of the dispersion using an oil agent (Comparative Example 5), the porous structure could not be confirmed, and agglomeration of powder was observed in some places.
As described above, the emulsified foundation adopting the form of the pickering emulsion can form a decorative film having a porous structure, and has an excellent effect of suppressing secondary adhesion due to the porous structure. confirmed.

Further, from the results of FIG. 3, the foundation of Example 6 had a high effect of suppressing secondary adhesion regardless of the leaving time. In particular, in the result of leaving the foundation for 1 minute on the assumption that the foundation was not dry, the amount of secondary adhesion was significantly suppressed as compared with Comparative Examples 4 and 5.

<Test Example 4> Confirmation test of influence of aqueous phase amount A foundation was prepared according to the formulation shown in Table 3 below.
The same test as in Test Example 4 was performed for each foundation, and the amount of secondary adhesion was evaluated. The results are shown in Table 3. As the dimethicone in Table 3, a non-volatile one was used unlike Tables 1 and 2.

<Test Example 5> Simulation of Porous Structure Occupancy in Cosmetic Film In Examples 7 to 12, 12 nm powder is adsorbed around 5 μm water droplets in a W / O emulsion, and the decorative film is stacked. The occupancy of the porous structure with respect to the thickness of was calculated. The results are shown in Table 3.

From the results in Table 3, it was shown that the greater the content of the aqueous phase or the content of water with respect to the total amount of the pickering emulsion, the more excellent the effect of suppressing secondary adhesion.
In particular, Examples 7, 8 and 9 having an aqueous phase content of 30% by mass or more or a water content of 25% by mass or more have a particularly excellent effect of suppressing secondary adhesion.
Examples 7 and 12 had the most excellent effect of suppressing secondary adhesion, and the secondary adhesion rate was less than 6% when the drying time was 1 minute, and the secondary adhesion rate was less than 1% when the drying time was 15 minutes. .. From this result, it was shown that the pickering emulsion of the present invention can form a decorative film having an excellent secondary adhesion suppressing effect even when the types of volatile oils are different.

Although the secondary adhesion suppressing effect of Examples 10 and 11 is inferior to that of Comparative Example 5 when the drying time is 15 minutes, the secondary adhesion suppressing effect when the drying time is 1 minute is Comparative Example. Better than 5. From this result, Examples 10 and 11 have an excellent effect of suppressing secondary adhesion as compared with Comparative Examples in a state in which secondary adhesion is most likely to occur and is not dried after coating. It can be said that.

The present invention can be applied to the design of a film structure having excellent adhesion and low secondary adhesion.

Claims (10)

A W / O type pickering emulsion containing an aqueous phase, an oil phase, and a hydrophobic powder, and containing 40% by mass or more of a volatile oil agent with respect to the total amount of the oil agent contained in the oil phase. .. The W / O-type pickering emulsion according to claim 1, wherein the content of the total amount of the aqueous phase is 5% by mass or more with respect to the total amount of the W / O-type pickering emulsion. The W / O type pickering emulsion according to claim 1 or 2, wherein the hydrophobic powder has an M value of 10 or more. The W / O type pickering emulsion according to any one of claims 1 to 3, wherein the primary particle size of the hydrophobized powder is 200 nm or less. The W / O type pickling emulsion according to any one of claims 1 to 4, wherein the hydrophobized powder is a powder coated with an acrylic resin and / or an organosilicon compound. .. The W / O type pickling emulsion according to any one of claims 1 to 5, wherein the volatile oil agent is a hydrocarbon oil and / or a volatile silicone oil. A cosmetic comprising the W / O type pickering emulsion according to any one of claims 1 to 6. The cosmetic according to claim 7, which is a foundation or a sunscreen agent. The process of preparing the aqueous phase and
Equipped with a process to prepare the oil phase
The oil phase contains an oil agent and a hydrophobic powder, and the oil agent contains 40% by mass or more of a volatile oil agent with respect to the total amount of the oil agent.
A method for producing a W / O type pickering emulsion, which comprises a step of mixing the aqueous phase and the oil phase to prepare an emulsion. It is an evaluation method of cosmetic film
The step of observing the surface or cross section of the cosmetic film obtained by applying the cosmetic containing the W / O type pickering emulsion and the effect of suppressing secondary adhesion when a porous structure is observed in the cosmetic film. A method for evaluating a cosmetic film, which comprises a step of evaluating the cosmetic film to have.