HK1185275B - Oil-in-water type emulsified cosmetic for sunscreen - Google Patents

Description

Sunscreen oil-in-water type emulsion cosmetic

Technical Field

The present invention relates to a sunscreen oil-in-water type emulsion cosmetic. More specifically, the present invention relates to a sunscreen oil-in-water type emulsion cosmetic containing hydrophobized zinc oxide as an ultraviolet scattering agent, wherein excellent emulsion stability is exhibited by uniformly and stably dispersing the hydrophobized zinc oxide in an oil phase.

Background

The sunscreen oil-in-water type emulsion cosmetic in which the hydrophobized ultraviolet scattering agent is dispersed in the internal phase can be used as a formulation system capable of achieving both a soft feeling in use and a high SPF.

Titanium oxide and zinc oxide are mainly used as an ultraviolet scattering agent (for example, patent document 1), and titanium oxide has a higher whiteness and a more excellent frictional feeling (きしみ) than zinc oxide, and therefore, zinc oxide is preferably used effectively for the preparation of a sunscreen cosmetic having an excellent appearance and a feeling in use. In addition, in order to stably incorporate zinc oxide into an oil phase, which is an internal phase of an oil-in-water type emulsion cosmetic, a technique of uniformly and stably dispersing zinc oxide in an oil component is extremely important.

As a technique for uniformly dispersing zinc oxide in an oil component, patent document 2 discloses an oil dispersion in which zinc oxide particles used in a sunscreen cosmetic are dispersed in an oil component.

In an example of the method for producing an oil dispersion of zinc oxide particles of patent document 1, a high-speed bead mill containing glass beads is used to disperse zinc oxide particles in oil, and as a method for uniformly dispersing zinc oxide in an oil component, a technique of performing physical uniform dispersion by OB mill (medium dispersion using beads) treatment is used.

However, although the method of uniformly dispersing zinc oxide in an oil component by OB milling has a strong dispersing power, on the other hand, OB milling is indispensable and can be produced only in a factory having OB milling, and therefore, there is a problem that the production site of a sunscreen cosmetic in which zinc oxide is uniformly dispersed in an oil component is limited.

On the other hand, as a sunscreen cosmetic excellent in dispersion stability of zinc oxide during storage, patent document 3 discloses a sunscreen cosmetic in which the surface of zinc oxide is surface-treated with an organic silicon compound having a specific structure, using a volatile organopolysiloxane and a silicone-based dispersant.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2010-222349

Patent document 2: japanese laid-open patent publication No. 5-213618

Patent document 3: japanese patent laid-open publication No. 2009-084171.

Disclosure of Invention

Problems to be solved by the invention

The present inventors have made extensive studies in view of the above-mentioned points, in order to achieve extremely high dispersibility of hydrophobized zinc oxide in sunscreen cosmetics containing the hydrophobized zinc oxide as an ultraviolet scattering agent, and as a result, have found that if a specific oil component and a dispersant are used and zinc oxide hydrophobized with a specific compound is used, an oil-in-water emulsion composition having extremely high dispersibility of zinc oxide in the oil component can be surprisingly obtained, and have completed the present invention.

The present invention aims to provide a sunscreen oil-in-water type emulsion cosmetic containing hydrophobized zinc oxide as an ultraviolet scattering agent, wherein the hydrophobized zinc oxide is uniformly and stably dispersed in an oil phase without using a pulverizing device such as OB mill, thereby exhibiting extremely excellent emulsion stability.

Means for solving the problems

Namely, the present invention provides a sunscreen oil-in-water type emulsion cosmetic characterized by blending the following components (a) to (F):

(A) zinc oxide subjected to hydrophobization treatment with octyltriethoxysilane and/or dimethylpolysiloxane;

(B) volatile oil components;

(C) liquid higher fatty acids;

(D) an organosilicon or sugar ester having a carboxyl group in the structure;

(E) a nonionic surfactant;

(F) and (3) water.

The present invention also provides the oil-in-water emulsion sunscreen cosmetic composition as described above, wherein the amount of the hydrophobized zinc oxide (a) is 3 to 18% by mass based on the total amount of the oil-in-water sunscreen cosmetic composition, and the amount of the volatile oil component (B) is 10/7 times or more the amount of the hydrophobized zinc oxide (a) in terms of mass ratio.

The present invention also provides the suncare oil-in-water type emulsion cosmetic as described above, wherein the volatile oil component (B) is decamethylcyclopentasiloxane and/or isododecane.

Further, the present invention provides a sunscreen oil-in-water type emulsion cosmetic characterized by further comprising (G) an ultraviolet absorber.

Effects of the invention

The present invention provides a sunscreen oil-in-water type emulsion cosmetic containing hydrophobized zinc oxide as an ultraviolet scattering agent, which can exhibit extremely excellent emulsion stability by uniformly and stably dispersing the hydrophobized zinc oxide in an oil phase.

Detailed Description

The present invention will be described in detail below.

[ (A) Zinc oxide hydrophobized with octyltriethoxysilane and/or dimethylpolysiloxane ]

In the present invention, the hydrophobizing agent for zinc oxide is limited to octyl triethoxysilane and/or dimethylpolysiloxane. If a hydrophobizing agent other than these is used, the dispersibility of zinc oxide is deteriorated. The dimethylpolysiloxane preferably has a polymerization degree of 100 to 1000.

The method for hydrophobizing zinc oxide is not particularly limited, and surface treatment is performed according to a conventional method. For example, zinc oxide hydrophobized with octyltriethoxysilane and/or dimethylpolysiloxane can be produced by mixing and stirring zinc oxide in octyltriethoxysilane and/or dimethylpolysiloxane for a certain period of time, and filtering the mixture. The dimethylpolysiloxane used herein is a liquid dimethylpolysiloxane that can be subjected to a hydrophobic treatment.

The zinc oxide used in the present invention is a fine powder, and preferably a fine powder having an average particle diameter of 10 to 80nm is used.

The amount of zinc oxide hydrophobized with octyltriethoxysilane and/or dimethylpolysiloxane is preferably 3 to 18 mass%, more preferably 5 to 12 mass%, and most preferably 5 to 8 mass% based on the total amount of the sunscreen oil-in-water type emulsion cosmetic.

If the amount of zinc oxide hydrophobized with octyltriethoxysilane and/or dimethylpolysiloxane is outside the above range, the dispersibility of zinc oxide may be deteriorated.

[ (B) volatile oil ]

The volatile oil used in the present invention may, for example, be a hydrocarbon oil of relatively low molecular weight, a linear silicone of relatively low molecular weight, or a cyclic silicone of relatively low molecular weight, and particularly preferably light-fluidity isoparaffin, isododecane, isohexadecane, volatile dimethylpolysiloxane, or cyclic polysiloxane. Specifically, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, and hexadecylcycloheptasiloxane are preferable. Light-weight, mobile isoparaffins, isododecane, isohexadecane, decamethylcyclopentasiloxane are particularly preferred.

The volatile oil component used in the present invention is a component constituting an oil phase of an inner phase of the sunscreen oil-in-water type emulsion cosmetic, together with the liquid higher fatty acid of the component (C) and the dispersant of the component (D), wherein the hydrophobized zinc oxide of the component (a) is uniformly dispersed in the oil component of the inner phase.

In the present invention, the hydrophobized zinc oxide of component (a) has dispersion stability, and therefore, a dispersion portion in which component (a) is dispersed only in components (B) to (D) is prepared, and other oil phase components are prepared in other portions. The dispersion portion and the other portion are then mixed to form an oil phase.

The oil component of the inner phase of the sunscreen oil-in-water emulsion cosmetic composition of the present invention is composed of the volatile oil component (B) and the liquid higher fatty acid component (C) as the main components, but it is preferable to blend about 1 to 2 mass% of hydrogenated polydecene with respect to the total amount of the sunscreen oil-in-water emulsion cosmetic composition in order to adjust the usability and improve the compatibility between the oil components.

The amount of the volatile oil is preferably 5 to 30% by mass, more preferably 7 to 18% by mass, and most preferably 7 to 12% by mass, based on the total amount of the sunscreen oil-in-water type emulsion cosmetic.

If the amount of the volatile oil is outside the above range, the dispersibility of zinc oxide may be deteriorated, and the feeling of use may be reduced.

The amount of the volatile oil is preferably 10/7 or more in terms of a mass ratio, which is the amount of the hydrophobized zinc oxide (a) added.

[ (C) liquid higher fatty acid ]

Examples of the liquid higher fatty acid used in the present invention include isostearic acid, oleic acid, linoleic acid, linolenic acid, etc., and isostearic acid is particularly preferably used.

In the present invention, the liquid higher fatty acid is a component constituting the oil component of the inner phase of the sunscreen oil-in-water type emulsion cosmetic together with the volatile oil component of component (B). In the oil component in the inner phase, the hydrophobized zinc oxide of the component (a) is uniformly dispersed, but if a liquid higher fatty acid is not blended, the dispersibility of the zinc oxide is lowered.

The amount of the liquid higher fatty acid is preferably 0.1 to 1% by mass, more preferably 0.3 to 0.8% by mass, and most preferably 0.5 to 0.7% by mass, based on the total amount of the sunscreen oil-in-water type emulsion cosmetic composition.

If the amount of the liquid higher fatty acid is outside the above range, the dispersibility of zinc oxide may be lowered.

[ (D) organosilicon or saccharide ester having carboxyl group in structure (dispersant) ]

Examples of the organosilicon having a carboxyl group in the structure used in the present invention include carboxydecyltrisiloxane and alkyl acrylate copolymer methylpolysiloxane. Particularly preferred is carboxydecyl trisiloxane.

Examples of the sugar ester used in the present invention include sorbitan sesquiisostearate, dipentaerythritol fatty acid ester, polyoxyethylene sorbitan monooleate, and polyoxyethylene sorbitan monostearate. Sorbitan sesquiisostearate is particularly preferred.

In the present invention, the component (D) functions as a dispersant for uniformly and stably dispersing the hydrophobized zinc oxide in the oil phase.

The amount of the silicone or sugar ester having a carboxyl group in the structure is preferably 0.1 to 0.7% by mass, more preferably 0.2 to 0.6% by mass, and most preferably 0.3 to 0.4% by mass, based on the total amount of the sunscreen oil-in-water type emulsion cosmetic.

If the amount of the silicone or sugar ester having a carboxyl group in the structure is outside the above range, the dispersibility of zinc oxide may be deteriorated.

[ (E) nonionic surfactant ]

The nonionic surfactant used in the present invention is a component blended as an emulsifier in the present invention for the purpose of producing a stable oil-in-water emulsion composition.

Specifically, examples of the lipophilic nonionic surfactant include sorbitan fatty acid esters (for example, sorbitan monooleate, sorbitan monoisostearate, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan sesquioleate, sorbitan trioleate, diglycerol sorbitan penta-2-ethylhexanoate, diglycerol sorbitan tetra-2-ethylhexanoate, and the like); glycerol polyglycerin fatty acid esters (e.g., cottonseed oil fatty acid glyceride, erucic acid glyceride, sesqui oleic acid glyceride, glyceryl monostearate, α' -oleic acid pyroglutamic acid glyceride, glyceryl monostearate, etc.); propylene glycol fatty acid esters (e.g., propylene glycol monostearate); hydrogenated castor oil derivatives; glycerol alkyl ethers, and the like.

Examples of the hydrophilic nonionic surfactant include POE-sorbitan fatty acid esters (for example, POE-sorbitan monooleate, POE-sorbitan monostearate and POE-sorbitan tetraoleate); POE-sorbitol fatty acid esters (e.g., POE-sorbitol monolaurate, POE-sorbitol monooleate, POE-sorbitol pentaoleate, POE-sorbitol monostearate, etc.); POE-glycerin fatty acid esters (for example, POE-monooleate such as POE-glycerin monostearate, POE-glycerin monoisostearate and POE-glycerin triisostearate); POE-fatty acid esters (e.g., POE-distearate, POE-monooleate, ethylene glycol distearate, etc.); POE-alkyl ethers (e.g., POE-lauryl ether, POE-oleyl ether, POE-stearyl ether, POE-behenyl ether, POE-2-octyldodecyl ether, POE-cholestanol ether, etc.); pluronic types (e.g., Pluronic, etc.); POE ･ POP-alkyl ethers (e.g., POE ･ POP-cetyl ether, POE ･ POP-2-decyltetradecyl ether, POE ･ POP-monobutyl ether, POE ･ POP-hydrogenated lanolin, POE ･ POP-glyceryl ether, etc.); TetraPOE ･ tetra POP-ethylenediamine condensates (for example, Tetronic); POE-castor oil ･ POE-hydrogenated castor oil derivatives (e.g., POE-castor oil, POE-hydrogenated castor oil monoisostearate, POE-hydrogenated castor oil triisostearate, POE-hydrogenated castor oil monopyroglutamic acid monoisostearic acid diester, POE-hydrogenated castor oil maleate, etc.); POE-beeswax ･ lanolin derivatives (e.g., POE-sorbitol beeswax, etc.); alkanolamides (e.g., coconut oil fatty acid diethanolamide, lauric acid monoethanolamide, fatty acid isopropanolamide, etc.); POE-propylene glycol fatty acid ester; POE-alkylamine; POE-fatty amides; sucrose fatty acid ester; alkyl ethoxy dimethylamine oxide; triolein phosphate and the like.

In the present invention, a hydrophilic surfactant is preferably used.

The amount of the nonionic surfactant is preferably 0.5 to 2.0% by mass, more preferably 0.8 to 1.7% by mass, and most preferably 1.0 to 1.5% by mass, based on the total amount of the sunscreen oil-in-water type emulsion cosmetic composition.

If the amount of the nonionic surfactant is outside the above range, the stability of the oil-in-water emulsion cosmetic may be lowered.

[ (F) Water ]

The water used in the present invention is not particularly limited, and may be pure water or ion-exchanged water, if specifically disclosed.

Water is a component of the aqueous phase that constitutes the outer phase of a sunscreen oil-in-water type emulsion cosmetic, together with other aqueous components.

The amount of water is suitably determined in accordance with the amount of oil constituting the oil phase of the inner phase, and is preferably 40 to 65% by mass, more preferably 45 to 60% by mass, and most preferably 50 to 55% by mass, based on the total amount of the sunscreen oil-in-water type emulsion cosmetic.

If the amount of water is outside the above range, the stability of the oil-in-water emulsion cosmetic may be lowered, and the feeling of use may be lowered.

[ (G) ultraviolet absorber ]

The sunscreen oil-in-water type emulsion cosmetic of the present invention may contain an arbitrary ultraviolet absorber. In order to improve the sunscreen effect, it is preferable to blend one or two or more ultraviolet absorbers.

Specific examples of the ultraviolet absorber include the following compounds.

(1) Benzoic acid-based ultraviolet absorber

Examples thereof include p-aminobenzoic acid (hereinafter abbreviated as PABA), PABA monoglyceride, N-dipropoxypPABA ethyl ester, N-diethoxypPABA ethyl ester, N-dimethylpPABA butyl ester, and N, N-dimethylpPABA ethyl ester.

(2) Anthranilic acid ultraviolet absorber

Such as N-acetyl homomenthyl anthranilate and the like.

(3) Salicylic acid-based ultraviolet absorber

For example, amyl salicylate, menthyl salicylate, homomenthyl salicylate, octyl salicylate, phenyl salicylate, benzyl salicylate, p-isopropyl phenyl salicylate, and the like.

(4) Cinnamic acid ultraviolet absorbent

For example, octyl cinnamate, ethyl 4-isopropyl cinnamate, methyl 2, 5-diisopropyl cinnamate, ethyl 2, 4-diisopropyl cinnamate, methyl 2, 4-diisopropyl cinnamate, propyl p-methoxycinnamate, isopropyl p-methoxycinnamate, isoamyl p-methoxycinnamate, octyl p-methoxycinnamate (2-ethylhexyl p-methoxycinnamate), 2-ethoxyethyl p-methoxycinnamate, cyclohexyl p-methoxycinnamate, ethyl α -cyano- β -phenylcinnamate, 2-ethylhexyl α -cyano- β -phenylcinnamate, glyceryl mono-2-ethylhexanoyl-di-p-methoxycinnamate, etc.

(5) Triazine-based ultraviolet absorber

Such as bisresorcinyltriazine.

More specifically, there are bis { [ 4- (2-ethylhexyloxy) -2-hydroxy ] phenyl } -6- (4-methoxyphenyl) 1,3, 5-triazine, 2,4, 6-tris {4- (2-ethylhexyloxycarbonyl) anilino }1,3, 5-triazine and the like.

(6) Other ultraviolet absorbers

For example 3- (4' -methylbenzylidene) -d, l-camphor, 3-benzylidene-d, l-camphor, 2-phenyl-5-methylbenzoxazole, 2' -hydroxy-5-methylphenylbenzotriazole, 2- (2' -hydroxy-5 ' -tert-octylphenyl) benzotriazole, 2- (2' -hydroxy-5 ' -methylphenyl) benzotriazole, dianhydrofenylmethane, 4-methoxy-4 ' -tert-butyldibenzoylmethane, 5- (3, 3-dimethyl-2-norbornenyl) -3-pentan-2-one. Pyridazine derivatives such as dimorpholinopyridazinone.

The amount of the ultraviolet absorber is suitably determined, and is preferably 5 to 15% by mass, more preferably 7.5 to 12% by mass, and most preferably 8 to 10% by mass, based on the total amount of the sunscreen oil-in-water type emulsion cosmetic.

[ oil-in-water type emulsion cosmetic ]

The sunscreen oil-in-water type emulsion cosmetic of the present invention may contain, in addition to the above essential components, components normally contained in cosmetics, such as a moisturizing agent, a thickener, a powder, an alcohol, a natural polymer, a synthetic polymer, a saccharide, an antioxidant, a buffer, various kinds of extract solutions, a stabilizer, a preservative, a pigment, and a perfume, as appropriate, within a range not impairing the effects of the present invention.

In the method for producing a sunscreen oil-in-water type emulsion cosmetic of the present invention, the dispersion of the zinc oxide hydrophobized with octyltriethoxysilane and/or dimethylpolysiloxane as the component (a) is prepared by mixing and stirring only the volatile oil component as the component (B) having good dispersibility, the liquid higher fatty acid as the component (C), and the dispersant as the component (D) with an HM mixer or the like to prepare a dispersion portion. Then, other oil components such as an oil component and a lipophilic ultraviolet absorber are prepared in the other part, and the other part is mixed with the dispersion part to prepare an oil phase. On the other hand, water as component (F), a hydrophilic nonionic surfactant as component (E), and aqueous components such as ethanol, a thickener, and a humectant are mixed to prepare an aqueous phase. Finally, the water phase and the oil phase are emulsified by a conventional method to obtain the sunscreen oil-in-water type emulsified cosmetic of the present invention.

The sunscreen oil-in-water type emulsion cosmetic of the present invention is an emulsion composition having extremely excellent emulsion stability.

Further, the sunscreen oil-in-water type emulsion cosmetic of the present invention uses zinc oxide as an ultraviolet scattering agent, and zinc oxide is uniformly dispersed in an oil phase, so that the problem of the ultraviolet scattering agent being conspicuous in whiteness during application can be suppressed, and the sunscreen oil-in-water type emulsion cosmetic has an excellent feeling of use that is non-abrasive and tender, and is suitable for use as, for example, a sunscreen emulsion or a sunscreen cream.

Examples

The present invention will be described more specifically with reference to the following examples, but the present invention is not limited thereto. Unless otherwise specified, the amount of the additive is expressed as% by mass relative to the total amount.

Emulsions as sunscreen oil-in-water emulsion cosmetics were prepared according to the formulations shown in "table 1" and "table 2" by a conventional method, and the following evaluations were performed.

[ dispersibility of hydrophobized Zinc oxide ]

The dispersion state of the hydrophobized zinc oxide in the emulsions of the examples and comparative examples immediately after production was visually observed using an optical microscope (400 × magnification), and was judged according to the following evaluation criteria.

< evaluation criteria >

O: the fine particles of the hydrophobized zinc oxide are uniformly dispersed in the oil component.

And (delta): the fine particles of the hydrophobized zinc oxide were dispersed in the oil, but the uniformity was slightly poor.

X: the fine particles of the hydrophobized zinc oxide are not uniformly dispersed in the oil component, but are present locally.

[ emulsion stability of oil-in-water emulsion cosmetic ]

The emulsions of examples and comparative examples were allowed to stand in thermostatic chambers at-5 ℃, 0 ℃, RT, 37 ℃, and 50 ℃ for 1 month, and then the dispersion state of the emulsified particles in the emulsions was visually observed using an optical microscope (400 times), and evaluated according to the following evaluation criteria.

< evaluation criteria >

O: in the emulsions placed in the thermostatic chambers at the respective temperatures, the emulsified particles were uniformly dispersed, and no change in appearance was observed.

X: in the emulsions placed in the thermostatic chambers at the respective temperatures, the emulsified particles were not uniformly dispersed, and an emulsion in which zinc oxide was removed from the internal phase was observed in terms of appearance.

[ Table 1]

< preparation method >

[ preparation of aqueous phase ]

The mixture was dissolved by adding (11), (12) and (22) to (1). Wetting (3) with (4), (5) and (6), and mixing with (1). Mixing a part of the ion-exchanged water (23) with the aqueous solution (10) obtained, and mixing the resulting solution with the solution (1).

[ preparation of oil phase ]

The mixture of (7), (8) and (9) was uniformly mixed and heated to 70 ℃. This was mixed with a dispersion portion of zinc oxide obtained by adding (19) to (21) to the oil components obtained by mixing (13) to (18) and dispersing the mixture in an HM mixer.

[ preparation of oil-in-Water emulsion composition ]

The oil phase (70 ℃ C.) containing the mixture (25) was emulsified in the above aqueous phase (70 ℃ C.). The mixed portion of (24) (2) was added and cooled to obtain an emulsion.

[ Table 2]

< preparation method >

Emulsions of the oil-in-water type emulsion cosmetics of comparative examples 1 to 7 were produced based on the production methods of the examples in table 1.

As is clear from "table 1" and "table 2", the sunscreen oil-in-water type emulsion cosmetics of examples 1 to 4, which contain all the essential components of the present invention, exhibited excellent effects in both dispersibility and emulsion stability of the hydrophobized zinc oxide.

That is, if the above-mentioned effects are considered from the viewpoint of the dispersant, it is understood from examples 1 to 4 and comparative example 1 that the use of a specific dispersant as the component (D) which is an essential component of the present invention has excellent effects in terms of dispersibility and emulsion stability of the hydrophobized zinc oxide.

However, in the case of using a dispersant other than the component (D) in comparative example 1 (in comparative example 1, a dispersant having a commonly used glycerin skeleton is used as the dispersant), the same effects as in examples 1 to 4 of the present invention are not exhibited, and the effects of dispersibility and emulsion stability of the hydrophobized zinc oxide are deteriorated. In addition, in comparative examples 2 and 3 in which no dispersant was used, the effects of dispersibility and emulsion stability of the hydrophobized zinc oxide were deteriorated.

On the other hand, from the results of comparative examples 4 to 6, it is understood that even when the dispersant of the component (D) used in the present invention is used, the effect of the dispersibility and the emulsion stability of the hydrophobized zinc oxide is deteriorated when the treating agent for the zinc oxide is not octyltriethoxysilane or dimethylpolysiloxane used in the component (a) (the hydrophobized zinc oxide of comparative examples 4 to 6 is hydrophobized by using dextrin palmitate as a hydrophobizing agent in general).

Further, from the results of comparative example 7, it is understood that even when the dispersant of the component (D) and the hydrophobized zinc oxide of the component (a) which are essential components of the present invention are used, if the liquid higher fatty acid of the component (C) is not blended, the dispersibility of the hydrophobized zinc oxide is lowered.

As described above, it was found that when dibutyldipolysiloxane polyglycerol was used as the dispersant and when no dispersant was added, zinc oxide could not be dispersed well regardless of the volatile oil content used.

In the case of zinc oxide treated with dextrin palmitate, the zinc oxide could not be dispersed well regardless of the dispersant used.

From the above results, it is considered that in order to adsorb the dispersant on the surface of zinc oxide to improve the dispersibility, it is important to make the surface treatment agent of zinc oxide and the dispersant compatible with each other.

In addition, the incorporation of isostearic acid as a liquid higher fatty acid is also effective for improving dispersibility. It is considered that the adsorption mechanism on the surface of zinc oxide contributes to the improvement of dispersibility, similarly to the dispersant.

The emulsions of examples 1 to 4 of the present invention are sunscreen oil-in-water emulsion cosmetics which suppress the property of the ultraviolet scattering agent that the whiteness is conspicuous when applied, and have a non-rubbing feel and a tender and excellent feeling of use.

Industrial applicability

The present invention is a sunscreen cosmetic composition containing hydrophobized zinc oxide as an ultraviolet scattering agent, which can stably disperse hydrophobized zinc oxide uniformly in an oil phase by using a specific essential compounding ingredient without using a pulverizing device such as OB mill, and can exhibit excellent emulsion stability even when prepared into an emulsion composition, and is therefore extremely useful as a sunscreen oil-in-water type emulsion cosmetic composition.

Further, according to the present invention, since the property of the ultraviolet scattering agent that the whiteness degree is conspicuous at the time of application is suppressed and the excellent feeling of use that is free from rubbing and is tender is provided, a very useful sunscreen oil-in-water type emulsion cosmetic can be provided.

Claims (4)

1. A sunscreen oil-in-water emulsion cosmetic characterized by containing the following components (A) to (F):

(A) zinc oxide hydrophobized with octyl triethoxysilane or dimethylpolysiloxane in an amount of 3 to 18% by mass based on the total amount of the sunscreen oil-in-water emulsion cosmetic;

(B) a volatile oil component in an amount of 5 to 30% by mass relative to the total amount of the sunscreen oil-in-water type emulsion cosmetic;

(C) liquid higher fatty acids;

(D) 0.1 to 0.7 mass% of an organosilicon or sugar ester having a carboxyl group in the structure, based on the total amount of the sunscreen oil-in-water type emulsion cosmetic;

(E) a nonionic surfactant;

(F) and (3) water.

2. The sunscreen oil-in-water type emulsion cosmetic composition according to claim 1, wherein the content of the hydrophobized zinc oxide (A) is 3 to 18% by mass relative to the total amount of the sunscreen oil-in-water type emulsion cosmetic composition, and the content of the volatile oil component (B) is 10/7 times or more the content of the hydrophobized zinc oxide (A) in terms of a mass ratio.

3. The oil-in-water emulsion cosmetic formulation for sunscreen according to claim 1 or 2, wherein the volatile oil component (B) is decamethylcyclopentasiloxane and/or isododecane in an amount of 5 to 30 mass% with respect to the total amount of the oil-in-water emulsion cosmetic formulation for sunscreen.

4. The sunscreen oil-in-water type emulsion cosmetic according to any one of claims 1 to 3, further comprising (G) an ultraviolet absorber in an amount of 5 to 15% by mass based on the total amount of the sunscreen oil-in-water type emulsion cosmetic.