Water-in-oil emulsion sunscreen cosmetic

Abstract

Provided is a water-in-oil emulsion sunscreen cosmetic which is a silicone-free and non-chemical water-in-oil emulsion sunscreen cosmetic not containing a silicone compound and a UV absorber, which has excellent dispersibility of powder such as a UV scattering agent, has a stable and transparent appearance, and has a sufficiently high UV protection effect with excellent water resistance. The water-in-oil emulsion sunscreen cosmetic of the present invention is characterized by containing (A) a surfactant, (B) a dispersant, (C) an oil component, (D) an organically modified clay mineral, and (E) a UV scattering agent, the content of the aforementioned (E) UV scattering agent being 10% by mass or more, and the water-in-oil emulsion sunscreen cosmetic not containing a silicone compound and a UV absorber.

Description

TECHNICAL FIELD

[0001] The present application relates to a water-in-oil emulsion sunscreen cosmetic. More specifically, it relates to a water-in-oil emulsion sunscreen cosmetic which is free from an organosilicon compound and a powder such as an ultraviolet scattering agent, has excellent dispersibility, has a stable and transparent appearance, and has a sufficient ultraviolet protection effect with excellent water resistance. BACKGROUND

[0002] An organosilicon compound such as a silicone oil is not only used in hair cosmetics such as shampoos, but also widely used in cosmetics for use on the skin such as foundations. The organosilicon compound has characteristics such as high water repellency, a light feeling of use without stickiness, and good spreadability on hair and skin, and has an effect of improving water resistance, feeling of use, and dispersibility of other ingredients of a cosmetic in which it is incorporated. Furthermore, the organosilicon compound is also widely used as a surface treatment agent for powder ingredients.

[0003] The organosilicon compound has the above-described advantages, but also has problems such as that, due to its high water repellency, makeup is difficult to remove with water, and a makeup remover for cleansing places a burden on the skin. Furthermore, the organosilicon compound is generally non-biodegradable, and thus there is a concern that it will accumulate in the environment for a long period of time, pollute the environment, and pose a risk of disrupting the ecosystem. Therefore, in recent years, cosmetics which do not incorporate an organosilicon compound, referred to as "organosilicon-free" or "non-organosilicon", have received attention.

[0004] In addition, particularly cosmetics with a sunscreen effect incorporate an ultraviolet absorber and an ultraviolet scattering agent as a means to help the skin resist ultraviolet rays, but in recent years, from the viewpoint of improving the feeling of use and reducing the burden on the skin, a "non-chemical" type sunscreen cosmetic which contains only an ultraviolet scattering agent that reflects and scatters ultraviolet rays by a physical means and does not contain an ultraviolet absorber that absorbs ultraviolet rays by a chemical action has been proposed.

[0005] For example, Patent Literature 1 discloses a non-chemical type sunscreen cosmetic which contains hydrophobically treated microparticulate zinc oxide and hydrophobically treated microparticulate titanium oxide, a water-soluble high molecular compound, and a spherical powder having a volume average particle diameter of 1 μm or more, and does not contain an organic ultraviolet absorber. However, in the cosmetic disclosed therein, the surface of the ultraviolet scattering agent is treated with an organosilicon compound or an organosilicon-based surfactant, organosilicon oil, or the like is incorporated, and thus an organosilicon compound is incorporated. Such a cosmetic has problems such as that, if the organosilicon compound which contributes to improving the dispersibility of other ingredients such as powders is removed, excellent powder dispersibility, a stable and transparent appearance, and a good feeling of use cannot be obtained.

[0006] Further, Patent Literature 2 discloses a non-chemical and non-silicone skin external agent containing 1 to 6% by weight of a nonionic surfactant which is liquid at normal temperature, 15 to 70% by weight of an oil which is liquid at normal temperature, 1 to 25% by weight of an ultraviolet scattering agent, and 10 to 60% by weight of water. However, the ultraviolet protection power is inherently low, and there are problems that the water resistance is poor and the ultraviolet protection power easily decreases due to contact with moisture.

[0007] In summary, for non-silicone cosmetics in which high powder dispersibility is difficult to achieve, it is technically very difficult to achieve sufficient ultraviolet protection power by stably dispersing an ultraviolet scattering agent instead of compounding an ultraviolet absorber.

[0008] Prior Art Documents

[0009] Patent Literature

[0010] Patent Literature 1: Japanese Patent Application Laid-Open No. 2019-156800

[0011] Patent Literature 2: Japanese Patent Application Laid-Open No. 2009-234933 SUMMARY

[0012] Problem to be solved by the invention

[0013] The present application has been achieved in order to solve the aforementioned problems, and provides a water-in-oil emulsion sunscreen cosmetic which is non-silicone and non-chemical, which is excellent in the dispersibility of a powder such as an ultraviolet scattering agent, which has a stable and transparent appearance, and which has a sufficient ultraviolet protection effect and excellent water resistance.

[0014] Solution to the problem

[0015] The present inventors have repeatedly conducted intensive research in order to solve the aforementioned problems, and as a result, have found that by compounding a surfactant, a dispersant, and an organically modified clay mineral, it is possible to stably disperse an ultraviolet scattering agent even without compounding a silicone compound, as a result of which it is possible to achieve a sufficient ultraviolet protection effect and excellent water resistance even without compounding an ultraviolet absorber, and to obtain a water-in-oil emulsion sunscreen cosmetic which has a stable and transparent appearance, thereby completing the present application.

[0016] That is, the gist of the present application is:

[0017] A water-in-oil emulsion sunscreen cosmetic containing:

[0018] (A) a surfactant,

[0019] (B) a dispersant,

[0020] (C) an oil fraction,

[0021] (D) organically modified clay mineral, and

[0022] (E) ultraviolet scattering agent,

[0023] The blending amount of the aforementioned (E) ultraviolet scattering agent is 10 mass% or more,

[0024] The water-in-oil emulsion sunscreen cosmetic does not contain a silicone compound and an ultraviolet absorber.

[0025] Effects of the invention

[0026] The water-in-oil emulsion sunscreen cosmetic of the present application is excellent in the stability of the dispersibility of powders such as a silicone compound and an ultraviolet scattering agent even if it does not contain the silicone compound. Therefore, it is possible to achieve a high ultraviolet protection effect even if an ultraviolet absorber is not blended, and it is possible to achieve a stable and transparent appearance. In addition, it also has the effect that the ultraviolet protection effect is not easily reduced even if it comes into contact with moisture. DETAILED DESCRIPTION

[0027] The water-in-oil emulsion sunscreen cosmetic of the present application necessarily contains (A) a surfactant, (B) a dispersant, (C) an oil component, (D) an organically modified clay mineral, and (E) an ultraviolet scattering agent. These will be described in detail below.

[0028] (A) Surfactant

[0029] The (A) surfactant is a surfactant generally used in cosmetics, and is not particularly limited as long as it is a surfactant other than a silicone-based surfactant, and is preferably a lipophilic nonionic surfactant selected from a polyoxyalkylene fatty acid ester or a polyglycerin fatty acid ester. Among these, one or more selected from a polyethylene glycol fatty acid ester, a polyglycerin fatty acid ester, and a polyoxyethylene hydrogenated castor oil can be preferably used. Among these surfactants, those having an HLB of 5 or less are particularly preferred.

[0030] The polyethylene glycol fatty acid ester includes any of a polyethylene glycol mono fatty acid ester and a polyethylene glycol di fatty acid ester. Among these, those having 4 to 12 oxyethylene groups are preferred, and for example, PEG-4 diisostearate, PEG-8 diisostearate, PEG-10 monoisostearate, and the like can be preferably used. As commercially available products, EMALEX DEG-di-IS (NIHON EMULSION Co., Ltd.), EMALEX 400 di-ISEX (NIHON EMULSION Co., Ltd.), EMALEX P1E-10 ES (NIHON EMULSION Co., Ltd.), and the like can be mentioned.

[0031] As the polyglyceryl fatty acid ester, for example, polyglyceryl-2 stearate, polyglyceryl-2 oleate, polyglyceryl-2 dioleate, polyglyceryl-2 isostearate, polyglyceryl-2 diisostearate, polyglyceryl-2 triisostearate, polyglyceryl-4 stearate, polyglyceryl-4 oleate, polyglyceryl-4 tristearate, polyglyceryl-4 pentaoleate, polyglyceryl-6 laurate, polyglyceryl-6 myristate, polyglyceryl-6 stearate, polyglyceryl-6 oleate, polyglyceryl-6 tristearate, polyglyceryl-6 tetrasuccinate, polyglyceryl-6 penta stearate, polyglyceryl-6 pentaoleate, polyglyceryl-6 polyricinoleate, polyglyceryl-10 laurate, polyglyceryl-10 myristate, polyglyceryl-10 stearate, polyglyceryl-10 isostearate, polyglyceryl-10 oleate, polyglyceryl-10 linoleate, polyglyceryl-10 distearate, polyglyceryl-10 diisostearate, polyglyceryl-10 tristearate, polyglyceryl-10 trioleate, polyglyceryl-10 penta stearate, polyglyceryl-10 penta hydroxystearate, polyglyceryl-10 penta isostearate, polyglyceryl-10 pentaoleate, polyglyceryl-10 hepta stearate, polyglyceryl-10 heptaoleate, polyglyceryl-10 deca stearate, polyglyceryl-10 deca isostearate, polyglyceryl-10 decaoleate, polyglyceryl-10 deca macadamia oilate, polyglyceryl-10 polyricinoleate, and the like can be exemplified. As the commercially available products, WOGEL-18DV (Matsumoto Fine Chemical Co., Ltd.), SUNSOFT A-193E-C (Taiyo Chemical Industry Co., Ltd.), COSMOL 42SV (Nikko Chemicals Co., Ltd.), and the like can be exemplified.

[0032] As the polyoxyethylene hydrogenated castor oil, for example, PEG-10 hydrogenated castor oil, PEG-20 hydrogenated castor oil, PEG-25 hydrogenated castor oil, PEG-30 hydrogenated castor oil, PEG-40 hydrogenated castor oil, PEG-50 hydrogenated castor oil, PEG-60 hydrogenated castor oil, PEG-80 hydrogenated castor oil, PEG-100 hydrogenated castor oil, and the like can be exemplified.

[0033] As the lower limit of the blending amount of the (A) surfactant in the water-in-oil emulsion sunscreen cosmetic of the present application, 1% by mass or more, further preferably 2% by mass or more, particularly preferably 4% by mass or more is preferable. In addition, as the upper limit of the blending amount of the (A) surfactant, 10% by mass or less, further preferably 8% by mass or less, particularly preferably 5% by mass or less is preferable. When the blending amount of the (A) surfactant is less than 1% by mass, there is a tendency to become emulsified poorly, and when it exceeds 10% by mass, there is a tendency to produce stickiness, and the use feeling is impaired or the water resistance is decreased.

[0034] (B) Dispersant

[0035] (B) dispersing agent is a component for dispersing a powder such as (E) ultraviolet scattering agent in the oil phase of the water-in-oil emulsion sunscreen cosmetic of the present application, and is not particularly limited as long as it is a dispersing agent other than silicone type and is generally used in cosmetics.

[0036] As a preferable example of (B) dispersing agent, one or more selected from liquid higher fatty acid, sorbitan fatty acid ester, and polyhydroxy stearic acid can be used. Among them, polyhydroxy stearic acid is particularly preferable.

[0037] Liquid higher fatty acid can include, for example, isostearic acid, oleic acid, linoleic acid, linolenic acid, and the like. Isostearic acid is particularly preferable. As a commercial product, isostearic acid SX (Sanyo Chemical Industries, Co., Ltd.) or the like can be used.

[0038] Sorbitan fatty acid ester can include, for example, sorbitan sesquiisostearate, sorbitan isostearate, sorbitan sesquioleate, sorbitan trioleate, and the like. Sorbitan sesquiisostearate, sorbitan isostearate, and sorbitan sesquioleate, which are liquid at room temperature, are particularly preferable. As a commercial product, ESTEMOL 182V (Nisshin OilliO Group, Inc.), EMALEX SPIS-150 (NIHON EMULSION Co., Ltd.), NIKKOL SI-15RV (Nikko Chemicals Co., Ltd.), EMALEX SPO-150 (NIHON EMULSION Co., Ltd.), NIKKOL SO-15V (Nikko Chemicals Co., Ltd.), NOFABLE SO-852S (NOF Corporation), COSMOL 82 (Nisshin OilliO Group, Inc.), and the like, as sorbitan sesquiisostearate, and EMALEX SPO-150 (NIHON EMULSION Co., Ltd.), NIKKOL SO-15V (Nikko Chemicals Co., Ltd.), NOFABLE SO-852S (NOF Corporation), COSMOL 82 (Nisshin OilliO Group, Inc.), and the like, as sorbitan sesquioleate, can be used.

[0039] Polyhydroxy stearic acid is a polymer of hydroxystearic acid having one hydroxyl group. The polymerization degree of hydroxystearic acid is preferably 3 to 12, and further preferably 4 to 8. As a commercial product, SALACOS HS-6C (Nisshin OilliO Group, Inc.) or the like can be used.

[0040] The lower limit of the blending amount of (B) dispersing agent in the water-in-oil emulsion sunscreen cosmetic of the present application is 0.5% by mass or more, further preferably 1% by mass or more, and particularly preferably 2.5% by mass or more. In addition, the upper limit of the blending amount of (B) dispersing agent is 10% by mass or less, further preferably 5% by mass or less, and particularly preferably 4% by mass or less. When the blending amount of (B) dispersing agent is less than 0.5% by mass, there is a tendency that the powder dispersion is poor, and when it exceeds 10% by mass, there is a tendency that the use feeling is impaired due to stickiness or emulsification is poor.

[0041] (C) oil

[0042] The (C) oil component constituting the oil phase can include, in addition to silicone oil, for example, hydrocarbon oil, ester oil, higher alcohol having a carbon number of 12 to 22, fatty acid having a carbon number of 12 to 22, and the like.

[0043] As the hydrocarbon oil, for example, liquid paraffin, liquid isoparaffin such as hydrogenated polyisobutene, heavy liquid isoparaffin, liquid petrolatum, squalane, pristane, squalene, volatile hydrocarbon oil (e.g., isododecane, isohexadecane, and the like), and the like can be mentioned.

[0044] As the ester oil, for example, isononyl isononanoate, isononyl isononanoate, octyldodecyl myristate, isopropyl myristate, isohexadecyl myristate, alkyl (C12-C15) benzoate such as benzoic acid alkyl ester, isopropyl palmitate, ethylhexyl palmitate, 2-hexyldecyl palmitate, and the like; monoester oil such as di-2-ethylhexyl sebacate, diisopropyl sebacate, diethylene glycol didecanoate, neopentyl glycol dicaprate, neopentyl glycol di(2-ethylhexanoate), diisostearyl malate, and the like; diester oil such as tri(2-ethylhexanoate) glycerin, tri(octanoate / decanoate) glycerin, and the like; and triester oil and the like can be mentioned.

[0045] As the higher alcohol having a carbon number of 12 to 22, for example, oleyl alcohol, 2-decyltetradecyl alcohol, dodecanol, isostearyl alcohol, octyldodecanol, and the like can be mentioned.

[0046] As the fatty acid having a carbon number of 12 to 22, for example, oleic acid, isostearic acid, linoleic acid, linolenic acid, and the like can be mentioned.

[0047] As the lower limit of the blending amount of the (C) oil component in the water-in-oil emulsion sunscreen cosmetic of the present application, 10% by mass or more, further preferably 20% by mass or more, and particularly preferably 30% by mass or more is preferable. In addition, as the upper limit of the blending amount of the (C) oil component, 90% by mass or less, further preferably 70% by mass or less, and particularly preferably 50% by mass or less is preferable. When the blending amount of the (C) oil component is less than 10% by mass, there is a tendency that powder dispersion becomes poor, and when it exceeds 90% by mass, there is a tendency that the use feeling becomes greasy.

[0048] (D) Organic Modified Clay Mineral

[0049] The (D) organic modified clay mineral is one of colloidal hydrous aluminum silicate having a three-layer structure, and a clay mineral represented by the following general formula (1) modified with a quaternary ammonium salt type cationic surfactant is representative.

[0050] (X, Y) 2―3 (Si, Al)4O 10 (OH)2Z 1 / 3 • nH2O (1)

[0051] (wherein, X = Al, Fe(III), Mn(III), Cr(III), Y = Mg, Fe(II), Ni, Zn, Li, Z = K, Na, Ca)

[0052] As specific examples, dimethyldistearylammonium hectorite (distearyldimethylammonium hectorite), dimethylalkylammonium hectorite, benzyldimethylstearylammonium hectorite, distearyldimethylammonium chloride-treated aluminum magnesium silicate, and the like can be given. Among them, distearyldimethylammonium hectorite is particularly preferable. As commercially available products, BENTONE 27 (benzyldimethylstearyl ammonium chloride-treated hectorite: Nomura Microsilica Co., Ltd.) and BENTONE 38 (distearyldimethylammonium chloride-treated hectorite: Nomura Microsilica Co., Ltd.) can be used.

[0053] As the lower limit of the blending amount of the (D) organically modified clay mineral in the water-in-oil emulsion sunscreen cosmetic of the present application, 0.1% by mass or more, further preferably 0.2% by mass or more, and particularly preferably 0.3% by mass or more is preferable. Also, as the upper limit of the blending amount of the (D) organically modified clay mineral, 1% by mass or less, further preferably 0.85% by mass or less, and particularly preferably 0.7% by mass or less is preferable. When the blending amount of the (D) organically modified clay mineral is less than 0.1% by mass, there is a tendency that sufficient water resistance cannot be obtained, and when it exceeds 1% by mass, there is a tendency that the use feeling becomes heavy.

[0054] (E) Ultraviolet Ray Scattering Agent

[0055] The (E) ultraviolet ray scattering agent can use a particulate powder which is subjected to hydrophobic treatment with a treating agent other than a surface organic silicon type.

[0056] As the particulate powder, one or two or more selected from the group consisting of titanium oxide, zinc oxide, barium sulfate, iron oxide, talc, mica, sericite, kaolin, mica titanium, Prussian blue, chromium oxide, chromium hydroxide, silicon dioxide, cerium oxide, and the like can be given. From the viewpoint of optical properties, a powder having a refractive index of 1.5 or more, such as zinc oxide, titanium oxide, cerium oxide, is particularly preferable.

[0057] As the method of hydrophobic treatment of the surface of the particulate powder, silica treatment with silica, hydrous silica, or the like; alkyl dextrin treatment with dextrin palmitate or the like; distearyldimethylammonium chloride treatment; fluorine treatment with perfluoroalkyl phosphate, perfluoroalcohol, or the like; amino acid treatment with N-acyl glutamic acid or the like; lecithin treatment; metal soap treatment with aluminum stearate treatment, magnesium isostearate treatment, or the like; fatty acid treatment; inorganic compound treatment; alkyl phosphate treatment, and the like can be given.

[0058] (E) The average primary particle diameter of the ultraviolet scattering agent is not particularly limited, and is preferably 100 nm or less, more preferably 80 nm or less. When the average primary particle diameter greatly exceeds 100 nm, a tendency to become a cause of floating white or white marks can be observed. The average primary particle diameter is measured by a conventional method such as a number average particle diameter obtained by image analysis using an electron microscope photograph.

[0059] (E) As the ultraviolet scattering agent, a commercially available product can also be used, and as a preferable commercially available product, ST-485SA (Titan Kogyo Co., Ltd.) which is an ultrafine particulate titanium oxide subjected to surface treatment with stearic acid, titanium oxide MT-100TV (TAYCA Co., Ltd.), and the like can be mentioned.

[0060] As the lower limit of the blending amount of the (E) ultraviolet scattering agent in the water-in-oil emulsion sunscreen cosmetic of the present application, 10% by mass or more, further preferably 15% by mass or more, particularly preferably 20% by mass or more is preferable. In addition, as the upper limit of the blending amount of the (E) ultraviolet scattering agent, 40% by mass or less, further preferably 35% by mass or less, particularly preferably 30% by mass or less is preferable. When the blending amount of the (E) ultraviolet scattering agent is less than 10% by mass, a sufficient ultraviolet protection effect cannot be obtained. In particular, if the blending amount of the (E) ultraviolet scattering agent is 20% by mass or more, a high protection effect is obtained and is preferable. On the other hand, if it exceeds 40% by mass, there is a tendency that the emulsion stability deteriorates due to poor dispersion of the powder.

[0061] The water-in-oil emulsion sunscreen cosmetic of the present application is a "silicone-free" cosmetic which does not contain a silicone compound, and is a "non-chemical" cosmetic which does not contain an ultraviolet absorber.

[0062] However, a trace amount of a silicone compound and an ultraviolet absorber can also be contained within a range that does not impair the effects of the present application and in which the disadvantages (poor washability, adverse effects on the environment or the skin, and the like) brought about by the silicone compound and the ultraviolet absorber are negligible. For example, in the case of a silicone oil, the blending amount should be stopped at 10% by mass or less of the entire oil, preferably 5% by mass or less of the entire oil, further preferably 1% by mass or less of the entire oil.

[0063] The "silicone compound" in the present specification refers to a compound having a siloxane (-Si-O-Si-) structure in the molecule (for example, organosilicon and siloxane) and silane (monosilane, oligosilane, polysilane, and silane derivatives such as alkylsilane, alkoxy silane, and the like), including silicone oil, silicone elastomer, silicone surfactant, and a powder subjected to surface treatment with a silicone compound. Note that the "silicone compound" of the present application does not include silicon dioxide (SiO2).

[0064] In addition, the "ultraviolet absorber" in the present specification means a water-soluble ultraviolet absorber and an oil-soluble ultraviolet absorber which are usually incorporated in sunscreen cosmetics. Examples include benzoic acid derivatives, salicylic acid derivatives, cinnamic acid derivatives, dibenzoylmethane derivatives, β,β-diphenyl acrylate derivatives, benzophenone derivatives, benzylidene camphor derivatives, phenyl benzimidazole derivatives, triazine derivatives, phenyl benzimidazole derivatives, anthranilic acid derivatives, imidazoline derivatives, benzylmalonate derivatives, 4,4-diarylbutadiene derivatives, and the like.

[0065] <Optional ingredients>

[0066] In the water-in-oil emulsion sunscreen cosmetic of the present application, in addition to the above-described (A) to (E) components, a component usually used in cosmetics can be incorporated within a range not impairing the effects of the present application. For example, an aqueous component, an alcohol, a humectant, a thickening agent, a powder component, a stabilizing agent, a chelating agent, a preservative, a perfume, and the like can be appropriately incorporated as needed.

[0067] The water-in-oil emulsion sunscreen cosmetic of the present application can be provided as a cosmetic of a type in which, when not in use, powders such as the ultraviolet scattering agent settle, and in which, when in use, the powders are uniformly redispersed by shaking.

[0068] The water-in-oil emulsion sunscreen cosmetic of the present application can be provided not only in the form of, for example, a sunscreen cream, a sunscreen lotion, a sunscreen milk, but also as a foundation, a makeup base, a color cosmetic, a hair cosmetic, and the like which impart a sunscreen effect.

[0069] Examples

[0070] The present application is further explained in detail by the following specific examples, but the present application is not limited by the following examples. In addition, the amounts incorporated in the following examples and the like indicate mass % unless otherwise specified. Before the specific description of each example, the evaluation methods employed are described.

[0071] <Transparency>

[0072] Each sample was filled in a plastic sample cell having an optical path length of 10 mm x an optical path width of 10 mm, and the transmittance in the wavelength region of 500 nm light was measured using a spectrophotometer (U-4100 manufactured by HITACHI, Ltd.). Compared with the transmittance of Example 1 of Table 1, evaluation was performed according to the following criteria.

[0073] (Evaluation Criteria)

[0074] A: Higher transmittance than Example 1

[0075] B: Same transmittance as Example 1

[0076] C: Lower than Example 1

[0077] <Emulsification stability>

[0078] Each sample was prepared, visually observed, and evaluated by the following criteria.

[0079] (Evaluation criteria)

[0080] A: No precipitation or separation was observed, and it was extremely stable

[0081] B: Emulsification was possible, but precipitation or separation over time was observed

[0082] C: Emulsification was not possible

[0083] <UV protection effect (SPF)>

[0084] The SPF value of each sample was measured in accordance with the international standard, i.e., ISO 24444 (2019). Compared with the transmittance of Example 1 of Table 1, evaluation was performed in accordance with the following criteria.

[0085] (Evaluation criteria)

[0086] A: The SPF value was higher than Example 1

[0087] B: The SPF value was the same as Example 1

[0088] C: The SPF value was lower than Example 1

[0089] <Water resistance>

[0090] Each sample was dropped on an S plate (a V-shaped groove-equipped PMMA plate of 5 x 5 cm, SPF MASTER-PA01) in an amount of 2 mg / cm 2 , spread with a finger for 60 seconds, dried for 15 minutes, and a coating film was formed. Using an uncoated plate as a control, the absorbance (400 to 280 nm) of the formed coating film was measured using a U-3500 type automatic recording spectrophotometer manufactured by Hitachi, Ltd., and the absorbance cumulative value before water bathing was calculated from the obtained measurement data.

[0091] Next, the measured plate was immersed in water, and stirred in this state in water for 30 minutes (with a 3-1 motor, 300 rpm). Then, after drying for about 15 to 30 minutes until the water droplets on the surface disappeared, the absorbance was measured again, and the absorbance cumulative value after water bathing was calculated from the obtained measurement data.

[0092] The water resistance, i.e., the change rate (%) of the absorbance cumulative value after water bathing, was calculated from the following formula.

[0093] Change rate (%) of absorbance cumulative value after water bathing = (absorbance cumulative value after water bathing - absorbance cumulative value before water bathing) / absorbance cumulative value before water bathing x 100

[0094] (absorbance cumulative value after water bath) / (absorbance cumulative value before water bath) x 100

[0095] Examples 1 to 8 and Comparative Examples 1 to 3

[0096] A water-in-oil emulsion sunscreen cosmetic having the composition shown in Tables 1 and 2 below was prepared as follows: the oily ingredient was heated and melted, and the powder was dispersed therein, and the water phase prepared separately was added thereto, and emulsified by stirring treatment, whereby the preparation was prepared. The transparency, emulsion stability, ultraviolet protection effect (SPF), and water resistance were evaluated according to the above evaluation methods.

[0097] [Table 1]

[0098]

[0099] [Table 2]

[0100]

[0101] As shown in Tables 1 and 2 above, Examples 1 to 8 were able to stably emulsify even without the use of an organic silicon compound by the use of a surfactant, a dispersant, and an organically modified clay mineral, and were able to disperse the ultraviolet scattering agent well. In addition, since a sufficient amount of the ultraviolet scattering agent was stably dispersed, an excellent ultraviolet protection effect was obtained even without the use of an ultraviolet absorber, and turbidity did not occur.

[0102] On the other hand, when an organic silicon-based surfactant was used, the emulsion stability and ultraviolet protection effect were insufficient in addition to the fact that a cosmetic without an organic silicon compound could not be obtained (Comparative Examples 1 to 3).

[0103] Note that although the data are not shown one by one, any of the examples and comparative examples showed a water resistance of the same degree as Example 1.

[0104] Examples 9 and Comparative Examples 4 to 9

[0105] A water-in-oil emulsion sunscreen cosmetic having the composition shown in Table 3 below was prepared in the same manner as above, and the transparency, emulsion stability, ultraviolet protection effect (SPF), and water resistance were evaluated according to the above evaluation methods.

[0106] [Table 3]

[0107]

[0108] As shown in Table 3 above, when using a dispersant that does not belong to the silicone compound, excellent results were obtained for all evaluation items (Example 9), and when using a silicone-based dispersant, results were obtained in which, in addition to the fact that a cosmetic without silicone was not achieved, dispersibility was poor and transparency was impaired (Comparative Examples 4 to 6).

[0109] In addition, when an oil component of the silicone type was used, in addition to the fact that a cosmetic without silicone was not achieved, sufficient ultraviolet protection effect was not obtained (Comparative Examples 7 to 9).

[0110] Note that, although data are not shown one by one, any of the examples and comparative examples showed water resistance to the same degree as Example 1.

[0111] <Example 10 and Comparative Examples 10 to 13>

[0112] A water-in-oil emulsion sunscreen cosmetic having the composition shown in Table 4 below was prepared in the same manner as described above, and transparency, emulsion stability, ultraviolet protection effect (SPF), and water resistance were evaluated in accordance with the evaluation method described above.

[0113] [Table 4]

[0114]

[0115] As shown in Table 4 above, when using a UV scattering agent that was surface-treated with a hydrophobizing agent that does not belong to the silicone compound, excellent results were obtained for all evaluation items (Example 10), and when using a UV scattering agent that was surface-treated with a hydrophobizing agent of the silicone type, results were obtained in which, in addition to the fact that a cosmetic without silicone was not achieved, dispersibility was poor and transparency was impaired (Comparative Examples 10 to 13).

[0116] Note that, although data are not shown one by one, any of the examples and comparative examples showed water resistance to the same degree as Example 1.

[0117] <Comparative Example 14>

[0118] A water-in-oil emulsion sunscreen cosmetic that was different from Example 1 only in that it did not contain an organically modified clay mineral (Comparative Example 14) was prepared in the same manner as described above, and transparency, emulsion stability, ultraviolet protection effect (SPF), and water resistance were evaluated in accordance with the evaluation method described above. The composition and evaluation results are shown in Table 5 below together with Example 1.

[0119] [Table 5]

[0120]

[0121] As shown in Table 5 above, the result of not compounding the organo-modified clay mineral was that sufficient ultraviolet protection was not obtained, and the water resistance was greatly deteriorated (Comparative Example 14).

Claims

1. A water-in-oil emulsion sunscreen cosmetic comprising: (A) a surfactant 1 to 10 mass%, (B) a dispersing agent 0.5 to 10 mass%, (C) an oil component 10 to 70 mass%, (D) an organically modified clay mineral 0.1 to 1 mass%, and (E) a UV scattering agent 10 to 40 mass%, (B) the dispersing agent comprises isostearic acid and sorbitan sesquiisostearate, The water-in-oil emulsion sunscreen cosmetic does not contain a silicone compound and a UV absorber.

2. The water-in-oil emulsified sunscreen cosmetic according to claim 1, wherein (A) the surfactant is a lipophilic nonionic surfactant selected from the group consisting of a polyoxyalkylene fatty acid ester or a polyglycerin fatty acid ester.

3. The water-in-oil emulsified sunscreen cosmetic according to claim 2, wherein (A) the surfactant is one or more selected from the group consisting of a polyethylene glycol fatty acid ester, a polyglycerin fatty acid ester, and a polyoxyethylene hydrogenated castor oil.

4. The water-in-oil emulsified sunscreen cosmetic according to any one of claims 1 to 3, wherein (A) the HLB of the surfactant is 5 or less.

5. The water-in-oil emulsified sunscreen cosmetic according to any one of claims 1 to 3, wherein (D) the organically modified clay mineral is lithium hectorite with a di-stearyl dimethyl ammonium.

6. The water-in-oil emulsified sunscreen cosmetic according to any one of claims 1 to 3, wherein (E) the UV scattering agent is hydrophobically treated with any of silica, an alkyl dextrin, distearyl dimethyl ammonium chloride, fluorine, an amino acid, lecithin, a metal soap, a fatty acid, and an alkyl phosphate ester.

7. The water-in-oil emulsified sunscreen cosmetic according to any one of claims 1 to 3, wherein (E) the UV scattering agent is hydrophobically treated with an inorganic compound.

8. The water-in-oil emulsified sunscreen cosmetic according to any one of claims 1 to 3, wherein (E) the UV scattering agent is present in an amount of 20 mass% or more.

9. The water-in-oil emulsion sunscreen cosmetic according to any one of claims 1 to 3, which, when not in use, causes powder to settle due to standing, and, when in use, causes the powder to be uniformly redispersed by shaking.

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