JP7649159B2 - Liquid oil-based cosmetics - Google Patents

Description

The present invention relates to a liquid oil-based cosmetic containing an oil-absorbing powder, and in particular to a liquid oil-based cosmetic using hydrophobically treated silica powder as the oil-absorbing powder.

Liquid oil-based cosmetics in which the oil phase forms a continuous phase, such as water-in-oil compositions, are widely used as cosmetics, and are particularly suitable for use as sunscreens, base cosmetics, and foundations, due to their excellent makeup-lasting properties.

In general, the viscosity of liquid oil-based cosmetics is adjusted to be low in order to improve the feel when used, such as the good spreadability and ease of application. However, in cosmetics with particularly low viscosity, powders may settle and become non-uniform. In such cases, measures are taken to prevent the powder from settling even with a low viscosity (Patent Document 1), or a method is used in which the container is shaken just before use to redisperse the settled powder and return the composition to a uniform state before application (Patent Document 2).

In addition, various powders are used in cosmetics depending on the purpose, and to prevent makeup from coming off due to sebum, powders that absorb sebum, such as spherical organic powders, are blended (Patent Documents 3 and 4).

More specifically, for example, Patent Document 4 discloses a water-in-oil emulsion cosmetic that contains the following components (A), (B), (C) and (H): (A) 0.1-10% by mass of a spherical organic powder having an oil absorption of 1.0 g/g or more and a water absorption of 1.0 g/g or less of squalane, (B) 0.1-10% by mass of a film-forming agent, (C) 5-60% by mass of a volatile oil, and (H) 5-70% by mass of water.

Patent No. 4566124 JP 2007-217393 A JP 2005-97246 A International Publication No. 2019/111831

On the other hand, the use of hydrophobized silica, an inorganic powder, as a powder that absorbs sebum in oil-based cosmetics, particularly low-viscosity water-in-oil cosmetics, has not been fully studied.

In response to this, the inventors focused on liquid oil-based cosmetics that use hydrophobically treated silica powder.

However, through intensive research by the present inventors, it was found that when hydrophobically treated silica powder is used, the problem of poor dispersibility arises.

In particular, as described above, in liquid oil-based cosmetics in which the viscosity is adjusted to be low, the hydrophobically treated silica powder dispersed in the oil phase tends to settle easily. When the hydrophobically treated silica powder settles, it is necessary to redisperse the hydrophobically treated silica powder by shaking. However, it has been found that when the hydrophobically treated silica powder is used, the dispersibility when redispersed by shaking (defined as "redispersibility" in this application) is also poor.

The present invention aims to improve the above situation, and its purpose is to provide a liquid oil-based cosmetic composition in which the hydrophobic treated silica powder has good redispersibility.

The present invention, which achieves the above objective, is as follows:

式（Ｉ）中、Ｒ_１は炭素原子数１～１２の直鎖又は分岐鎖のアルキル基、若しくはフェニル基を示し；Ｒ_２は炭素原子数２～１１のアルキレン基を示し；ｐは１０～１２０の数であり；ｑは１～１１の数である。
〈態様２〉
前記疎水処理シリカ粉末のオレイン酸の吸油量が、１．０ｍｌ／ｇ以上である、態様１に記載の化粧料。
〈態様３〉
前記揮発性シリコーン油が、直鎖ジメチコンである、態様１又は２に記載の化粧料。
〈態様４〉
（ｅ）紫外線散乱剤を更に含む、態様１～３のいずれか一項に記載の化粧料。
〈態様５〉
（ｆ）皮膜形成剤を更に含む、態様１～４のいずれか一項に記載の化粧料。
〈態様６〉
油中水型である、態様１～５のいずれか一項に記載の化粧料。
〈態様７〉
前記疎水処理シリカ粉末が、シリコーン処理されたシリカ粉末である、態様１～６のいずれか一項に記載の化粧料。
〈態様８〉
前記ポリグリセリン変性シリコーンが、ビスブチルジメチコンポリグリセリル－３である、態様１～７のいずれか一項に記載の化粧料。
〈態様９〉
使用時に振とうして再分散させる再分散型化粧料である、請求項１～８のいずれか一項に記載の化粧料。 <Aspect 1>
A liquid oil-based cosmetic composition comprising the following components (a) to (c):
(a) volatile silicone oil 5.0 to 60 mass%;
(b) hydrophobic treated silica powder 0.1 to 10 mass%;
(c) 0.05 to 5.0 mass% of a polyglycerin-modified silicone represented by the following formula (I):

In formula (I), R ₁ represents a linear or branched alkyl group having 1 to 12 carbon atoms, or a phenyl group; R ₂ represents an alkylene group having 2 to 11 carbon atoms; p is a number from 10 to 120; and q is a number from 1 to 11.
<Aspect 2>
A cosmetic preparation according to aspect 1, wherein the hydrophobically treated silica powder has an oil absorption of oleic acid of 1.0 ml/g or more.
<Aspect 3>
A cosmetic preparation according to aspect 1 or 2, wherein the volatile silicone oil is linear dimethicone.
<Aspect 4>
(e) The cosmetic preparation according to any one of Aspects 1 to 3, further comprising an ultraviolet scattering agent.
<Aspect 5>
The cosmetic preparation according to any one of Aspects 1 to 4, further comprising (f) a film-forming agent.
<Aspect 6>
A cosmetic preparation according to any one of Aspects 1 to 5, which is a water-in-oil type.
Aspect 7
A cosmetic preparation according to any one of Aspects 1 to 6, wherein the hydrophobic treated silica powder is a silicone treated silica powder.
<Aspect 8>
A cosmetic preparation according to any one of Aspects 1 to 7, wherein the polyglycerin-modified silicone is bis-butyldimethicone polyglyceryl-3.
<Aspect 9>
The cosmetic preparation according to any one of claims 1 to 8, which is a redispersible cosmetic preparation that is redispersed by shaking when used.

The present invention can provide a liquid oil-based cosmetic product that has good redispersibility of hydrophobically treated silica powder.

式（Ｉ）中、Ｒ_１は炭素原子数１～１２の直鎖又は分岐鎖のアルキル基、若しくはフェニル基を示し；Ｒ_２は炭素原子数２～１１のアルキレン基を示し；ｐは１０～１２０の数であり；ｑは１～１１の数である。 <Liquid oil-based cosmetics>
The liquid oily cosmetic composition of the present invention (hereinafter also simply referred to as the "cosmetic composition of the present invention") contains the following components (a) to (c):
(a) volatile silicone oil 5.0 to 60 mass%;
(b) hydrophobic treated silica powder 0.1 to 10 mass%;
(c) 0.05 to 5.0 mass% of a polyglycerin-modified silicone represented by the following formula (I):

In formula (I), R ₁ represents a linear or branched alkyl group having 1 to 12 carbon atoms, or a phenyl group; R ₂ represents an alkylene group having 2 to 11 carbon atoms; p is a number from 10 to 120; and q is a number from 1 to 11.

As mentioned above, it was found that when hydrophobically treated silica powder is used in oil-based cosmetics, particularly in low-viscosity water-in-oil cosmetics, there is a problem of poor redispersibility. This is presumably because hydrophobically treated silica powder is made by subjecting the surface of hydrophilic silica powder to a hydrophobic treatment, so part of the powder surface is in a hydrophilic state, which causes it to aggregate in the oil phase.

In order to solve this problem, the inventors have conducted extensive research and found that the incorporation of polyglycerin-modified silicone represented by the above formula (I) results in specifically good redispersibility for hydrophobic treated silica powder. Without being limited to theory, this is believed to be because the affinity between the polyglycerin-modified silicone represented by the above formula (I) used as a dispersant in volatile silicone oil and the hydrophobic treated silica powder is greater than the affinity between this polyglycerin-modified silicone and volatile silicone oil, and therefore the polyglycerin-modified silicone is maintained on the surface of the hydrophobic treated silica powder even when it is shaken to redisperse, and is able to function to disperse the hydrophobic treated silica powder in the volatile silicone oil.

In contrast, other common dispersants are believed to have insufficient affinity for hydrophobic treated silica powder or to be insufficient in their ability to disperse hydrophobic treated silica powder in silicone oil.

It has been known that the polyglycerin-modified silicone represented by the above formula (I) can be used as a silicone surfactant to disperse metal oxide particles such as titanium oxide, but its use from the perspective of redispersion as in the present invention has not been suggested. Furthermore, as shown in Comparative Example 8 described below, it was found that when redispersing metal oxide particles such as silicone-treated titanium oxide, even when the polyglycerin-modified silicone represented by the above formula (I) is blended in the same manner as in the present invention, redispersibility cannot be improved.

(a) Volatile Silicone Oil
The cosmetic of the present invention contains (a) a volatile silicone oil. By containing a volatile silicone oil, for example, stickiness can be suppressed, and the effect of improving the uniformity when a makeup cosmetic is applied over the cosmetic applied to the skin can be obtained.

In the present invention, "volatile" refers to a material that exhibits a volatile content of more than 5% when left at 105°C for 3 hours under atmospheric pressure. From the viewpoint of further exerting the effects of the present invention, the volatile content that serves as an indicator of volatility is preferably 10% or more, 20% or more, 40% or more, 50% or more, 60% or more, 80% or more, or 100%. In addition, in this disclosure, "non-volatile" refers to a material that exhibits a volatile content of 5% or less when left at 105°C for 3 hours. Here, the volatile content refers to the weight change rate value measured by a gravimetric method after placing filter paper on a glass petri dish and dropping about 0.2 g of the sample on the filter paper.

In the present invention, examples of volatile silicone oils include, but are not limited to, dimethicone. The volatile silicone oil may be either chain-like or cyclic. The chain-like volatile silicone oil may be either linear or branched, with linear silicone oils being particularly preferred.

The viscosity of the volatile silicone oil may be, for example, 0.7 cs to 3.0 cs.

In addition, commercially available volatile silicone oils can be used. Examples of commercially available volatile silicone oils that can be used include, but are not limited to, Silicone KF-96A-2cs (dimethicone), Silicone KF-96A-1.5cs (dimethicone), and Silicone KF56 (diphenylsiloxyphenyl trimethicone) manufactured by Shin-Etsu Chemical Co., Ltd.

In the cosmetic composition of the present invention, one or more volatile silicone oils may be used. The content of the volatile silicone oil in the cosmetic of the present invention may be 5.0% by mass or more, 6.0% by mass or more, 7.0% by mass or more, 8.0% by mass or more, 9.0% by mass or more, 10% by mass or more, 11% by mass or more, 12% by mass or more, 13% by mass or more, 14% by mass or more, 15% by mass or more, 16% by mass or more, 17% by mass or more, 18% by mass or more, 19% by mass or more, 20% by mass or more, 21% by mass or more, 22% by mass or more, 23% by mass or more, 24% by mass or more, 25% by mass or more, 26% by mass or more, 27% by mass or more, 28% by mass or more, 29% by mass or more, or 30% by mass or more, and may be 60% by mass or less, 50% by mass or less, 40% by mass or less, or 30% by mass or less, relative to the total amount of the cosmetic.

(b) Hydrophobically Treated Silica Powder
The cosmetic of the present invention contains (b) a hydrophobically treated silica powder. By containing the hydrophobically treated silica powder, the cosmetic of the present invention can absorb sebum, thereby preventing makeup from coming off due to sebum.

In the present invention, the hydrophobically treated silica powder refers to silica powder whose surface has been hydrophobically treated. Here, the hydrophobizing treatment may be, for example, a silicone-based treatment such as dimethicone or methicone. From the viewpoint of further exerting the effects of the present invention, it is preferable that the hydrophobically treated silica powder is a silicone-treated silica powder.

In the present invention, the silica powder may be porous silica particles or silica particles having an uneven surface, but from the viewpoint of improving the sebum absorption effect, porous silica particles are preferable. The shape of the silica particles is not particularly limited, and may be, for example, spherical, approximately spherical, or spheroidal. The silica particles may be disintegrative silica particles, particularly silica particles that break under the shear force of a finger.

The average particle size of the hydrophobically treated silica powder is not particularly limited and may be, for example, 1 to 30 μm. In the present invention, the average particle size can be calculated as the diameter of a circle equivalent to the projected area of the primary particles observed by SEM or TEM.

In the present invention, the oil absorption of the hydrophobic treated silica powder is evaluated by the amount (ml) of oleic acid that the hydrophobic treated silica powder can absorb per gram (i.e., "oil absorption of oleic acid (ml/g)"). Note that oleic acid is a typical unsaturated free fatty acid in sebum. In the present invention, the oil absorption of oleic acid of the hydrophobic treated silica powder may be 1.0 ml/g or more, 1.1 ml/g or more, 1.2 ml/g or more, 1.3 ml/g or more, 1.4 ml/g or more, 1.5 ml/g or more, 1.6 ml/g or more, 1.7 ml/g or more, 1.8 ml/g or more, 1.9 ml/g or more, 2.0 ml/g or more, 2.1 ml/g or more, 2.2 ml/g or more, or 2.3 ml/g or more, and may be 5.0 ml/g or less. The oil absorption of oleic acid of hydrophobically treated silica powder can be determined by referring to, for example, "JIS-K JIS K 5101-13-1 Japanese Industrial Standards Pigment Test Methods - Part 13: Oil Absorption - Section 1: Refined Linseed Oil Method."

The hydrophobic silica powder may be commercially available. An example of a commercially available hydrophobic silica powder is SA-SA-705 (product name) manufactured by Miyoshi Kasei Co., Ltd., but is not limited to this.

In the cosmetic of the present invention, one or more types of hydrophobic treated silica powder can be used. From the viewpoint of improving the sebum absorption effect, the content of the hydrophobic treated silica powder in the cosmetic of the present invention may be 0.1 mass% or more, 0.5 mass% or more, 1.0 mass% or more, 1.5 mass% or more, 2.0 mass% or more, 2.5 mass% or more, 3.0 mass% or more, 3.5 mass% or more, 4.0 mass% or more, 4.5 mass% or more, 5.0 mass% or more, 5.5 mass% or more, 6.0 mass% or more, 6.5 mass% or more, 7.0 mass% or more, 7.5 mass% or more, or 8.0 mass% or more, and may be 10 mass% or less, 9.0 mass% or less, 8.0 mass% or less, 7.0 mass% or less, or 6.0 mass% or less.

式（Ｉ）中、Ｒ_１は炭素原子数１～１２の直鎖又は分岐鎖のアルキル基、若しくはフェニル基を示し；Ｒ_２は炭素原子数２～１１のアルキレン基を示し；ｐは１０～１２０の数であり；ｑは１～１１の数である。 (c) Polyglycerin-modified silicone
The cosmetic of the present invention contains (c) polyglycerin-modified silicone. As described above, the cosmetic of the present invention can improve the redispersibility of the hydrophobic treated silica powder by containing this polyglycerin-modified silicone. The polyglycerin-modified silicone is represented by the following formula (I).

In formula (I), R ₁ represents a linear or branched alkyl group having 1 to 12 carbon atoms, or a phenyl group; R ₂ represents an alkylene group having 2 to 11 carbon atoms; p is a number from 10 to 120; and q is a number from 1 to 11.

The polyglycerin-modified silicone represented by the above formula (I) can be obtained, for example, by adding a solution of chloroplatinic acid in isopropyl alcohol to a mixture of polyglycerin diallyl ether and one-terminated hydrogenated dimethylpolysiloxane, heating and reacting the mixture, adding an aqueous hydrochloric acid solution to the mixture, subjecting the mixture to thermal hydrolysis, adding sodium bicarbonate water to neutralize the mixture, purifying the mixture, and evaporating the mixture. Note that the polyglycerin-modified silicone according to the present invention is not limited to this manufacturing method.

The polyglycerin-modified silicone of the present invention includes, for example, bis-butyl dimethicone polyglyceryl-3, which is defined in the cosmetic labeling name, but is not limited to this.

In addition, the polyglycerin-modified silicone represented by the above formula (I) may be a commercially available product.

In the cosmetic of the present invention, one or more polyglycerin-modified silicones represented by the above formula (I) can be used. The content of the polyglycerin-modified silicones represented by the above formula (I) in the cosmetic of the present invention may be 0.05% by mass or more, 0.1% by mass or more, 0.2% by mass or more, 0.3% by mass or more, 0.4% by mass or more, 0.5% by mass or more, 0.6% by mass or more, 0.7% by mass or more, 0.8% by mass or more, 0.9% by mass or more, 1.0% by mass or more, 1.2% by mass or more, 1.5% by mass or more, 1.8% by mass or more, 2.0% by mass or more, 2.2% by mass or more, 2.5% by mass or more, 2.8% by mass or more, 3.0% by mass or more, 3.2% by mass or more, or 3.5% by mass or more, and may be 5.0% by mass or less, 4.0% by mass or less, or 3.0% by mass or less, based on the total amount of the cosmetic, from the viewpoint of improving the redispersibility of the hydrophobic treated silica powder.

<Other Ingredients>
The cosmetic preparation of the present invention may contain the above-mentioned components (a) to (c) in a total amount of 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, or 90% by mass or more relative to the total amount of the cosmetic preparation. The cosmetic preparation of the present invention may further contain other components in addition to the above-mentioned components (a) to (c). The other components will be described below as examples, but are not intended to limit the cosmetic preparation of the present invention.

(d) Water
The cosmetic preparation of the present invention may contain (d) water. As the water, water that can be used in cosmetics, such as ion-exchanged water, may be used.

In the cosmetic of the present invention, when water is contained, the content of water may be 5.0% by mass or more, 10% by mass or more, 12% by mass or more, 15% by mass or more, 18% by mass or more, 20% by mass or more, 22% by mass or more, 25% by mass or more, 28% by mass or more, 30% by mass or more, 32% by mass or more, 35% by mass or more, 38% by mass or more, 40% by mass or more, 42% by mass or more, or 45% by mass or more, and may be 70% by mass or less, 60% by mass or less, or 50% by mass or less, based on the total amount of the cosmetic.

(e) Ultraviolet Scattering Agent)
The cosmetic preparation of the present invention may further contain an ultraviolet ray scattering agent. The ultraviolet ray scattering agent exhibits the effect of scattering or blocking ultraviolet rays.

Examples of ultraviolet scattering agents include, but are not limited to, titanium oxide, zinc oxide, cerium oxide, or powders of mixtures thereof. Furthermore, the titanium oxide and zinc oxide may be fine particles of titanium oxide and zinc oxide having a particle size of, for example, 10 to 50 nm. Furthermore, the titanium oxide and zinc oxide may be surface-treated. Examples of surface treatments include, but are not limited to, fatty acid treatment and fatty acid ester treatment.

Also, commercially available UV scattering agents can be used.

In the cosmetic of the present invention, when an ultraviolet scattering agent is included, the content thereof may be, for example, 1.0% by mass or more, 2.0% by mass or more, 3.0% by mass or more, 4.0% by mass or more, 5.0% by mass or more, or 6.0% by mass or more relative to the total amount of the cosmetic, and may be 25% by mass or less, 20% by mass or less, 15% by mass or less, or 10% by mass or less.

((f) Film-Forming Agent)
The cosmetic composition of the present invention may further contain a film-forming agent. The film-forming agent can provide a makeup-lasting effect.

Examples of film-forming agents include, but are not limited to, fluorine-modified silicone resins, trimethylsiloxysilicate, and alkyl silicone resins. The film-forming agent may be in a solid state at 25°C, and if in a solid state, may be dissolved in a solvent before use.

Also, commercially available film-forming agents can be used. Examples of commercially available film-forming agents include, but are not limited to, fluorosilicone resin X66-C8636 (trifluoroalkyldimethyltrimethylsiloxysilicate/dimethicone) manufactured by Momentive Performance Materials Japan LLC.

In the cosmetic of the present invention, when a film-forming agent is included, its content may be, for example, 0.1% by mass or more, 0.5% by mass or more, 1.0% by mass or more, 1.5% by mass or more, 2.0% by mass or more, 2.5% by mass or more, or 3.0% by mass or more, and may be 10% by mass or less, 8% by mass or less, 6% by mass or less, or 4% by mass or less, relative to the total amount of the cosmetic. When the film-forming agent is dissolved in a solvent, its content as a solid content may be within the above range.

(Surfactant)
The polyglycerin-modified silicone represented by the above-mentioned formula (I) is a type of silicone-based surfactant that functions as a dispersant, but the cosmetic preparation of the present invention may further contain other surfactants, for example, surfactants that function as emulsifiers, and may further contain, for example, silicone-based surfactants or nonionic surfactants such as polyglycerin fatty acid esters.

Here, examples of silicone surfactants other than the polyglycerin-modified silicone represented by the above formula (I) include, but are not limited to, polyether-modified silicones in which the polyether chain is located on the side chain (hereinafter also simply referred to as "polyether-modified silicones"), polyglycerin-modified silicones, etc.

Specific examples of these surfactants include, but are not limited to, PEG-10 dimethicone, PEG-9 polydimethylsiloxyethyl dimethicone, and lauryl PEG-9 polydimethylsiloxyethyl dimethicone, as defined by the cosmetic labeling name.

Commercially available products of these surfactants include, but are not limited to, KF-6017, KF-6028, and KF-6038 manufactured by Shin-Etsu Chemical Co., Ltd.

(Non-volatile silicone oil)
The cosmetic of the present invention may further contain an oil component other than the above-mentioned volatile silicone oil, for example, a non-volatile silicone oil. Examples of non-volatile silicone oils include, but are not limited to, silicone oils other than the above-mentioned volatile silicone oils, such as the commercially available silicone KF-96A-6T (dimethicone).

When non-volatile silicone oil is included, its content may be, for example, 1.0 to 10% by mass relative to the total amount of the cosmetic.

(Water-soluble components)
The cosmetic composition of the present invention may further contain a water-soluble component such as a lower alcohol, for example, ethanol, propanol, butanol, pentanol, and hexanol, but is not limited thereto.

When water-soluble ingredients are included, their content may be, for example, 1.0 to 10% by mass relative to the total amount of the cosmetic.

(Ultraviolet absorber)
The cosmetic composition of the present invention may further contain an ultraviolet absorbing agent. Examples of the ultraviolet absorbing agent include, but are not limited to, benzoic acid derivatives, salicylic acid derivatives, cinnamic acid derivatives, dibenzoylmethane derivatives, β,β-diphenylacrylate derivatives, benzophenone derivatives, benzylidene camphor derivatives, phenylbenzimidazole derivatives, triazine derivatives, phenylbenzotriazole derivatives, anthranil derivatives, imidazoline derivatives, benzalmalonate derivatives, and 4,4-diarylbutadiene derivatives.

When an ultraviolet absorber is included, its content may be, for example, 1.0 to 10% by mass relative to the total amount of the cosmetic.

(Coloring agent)
The cosmetic of the present invention may further contain a coloring agent, examples of which include, but are not limited to, red pigments such as red iron oxide or iron titanate, yellow pigments such as yellow iron oxide or ocher, black pigments such as black iron oxide, purple pigments such as mango violet, green pigments such as chromium oxide, blue pigments such as Prussian blue, and mixtures thereof.

When a coloring agent is included, its content may be, for example, 0.001 to 10% by mass relative to the total amount of the cosmetic.

In addition to the above, the cosmetic of the present invention may further contain ingredients that can be used in ordinary cosmetic preparations, such as preservatives, thickeners, pH adjusters, fragrances, moisturizers, blood circulation promoters, cooling agents, antiperspirants, disinfectants, or skin activators, so long as the effects of the present invention are not impaired.

<form>
The cosmetic composition of the present invention may be a redispersible cosmetic composition that is redispersed by shaking when used.

The cosmetic of the present invention may be a water-in-oil type. Water-in-oil type cosmetics are preferred from the viewpoints of moisturizing properties and water resistance.

Here, the water-in-oil cosmetic can be produced by a conventional method. More specifically, the cosmetic of the present invention may be produced by the following procedure. That is, at a predetermined temperature of about 25°C, the powder phase (hydrophobically treated silica powder, and optionally added UV scattering agents, colorants, etc.) is added to the mixed oil phase components (volatile silicone oil, and optionally added film-forming agents, etc.) and dispersed. Thereafter, the water phase components (water, and optionally added water-soluble components) are added and stirred to obtain the water-in-oil cosmetic.

The cosmetic of the present invention may be applied to cosmetics such as emulsions, makeup bases, liquid foundations, and sunscreens. The cosmetic of the present invention may be used alone or overlaid with powder cosmetics such as liquid foundations, powder foundations, and face powders.

<viscosity>
The viscosity of the cosmetic of the present invention may be, for example, 10,000 mPa·s or less, or 8,000 mPa·s or less from the viewpoint of improving spreadability and ease of application, and may be 100 mPa·s or more from the viewpoint of suppressing dripping during application. Note that in the present invention, the viscosity of the cosmetic may be measured using, for example, a BL-type viscometer (VS-A type, manufactured by Shibaura Systems Co., Ltd., 30° C.) with a rotor No. 3 under measurement conditions of 12 rpm and 1 minute.

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these. In the following, the contents are shown in mass % unless otherwise specified.

The cosmetics of the examples and comparative examples shown in Tables 1 and 2 below were prepared by conventional methods, and the redispersibility of each of the obtained cosmetics was evaluated according to the following criteria. The results are shown in Table 1.

(Evaluation of redispersibility)
The cosmetic compositions of each of the Examples and Comparative Examples were centrifuged using a Hitachi centrifuge (himac CF702), and the state of each cosmetic composition was evaluated. The evaluation criteria were as follows:
A: No sedimentation of particles occurs when shaken up and down 10 times;
B: When shaken up and down 10 times, some of the particles settle;
C: When shaken up and down 10 times, most of the particles (more than half by visual inspection) settled.

The "other common ingredients" in Table 1 are shown in Table 2 below.

表１から明らかなように、実施例１～３の化粧料は、いずれも再分散性が良好であることが分かった。

As is clear from Table 1, it was found that all of the cosmetics of Examples 1 to 3 had good redispersibility.

In contrast, Comparative Examples 1 to 7, which do not contain "bis-butyl dimethicone polyglyceryl-3," were found to have poor redispersibility. In Comparative Examples 2 to 7, it was also found that the redispersibility could not be improved even when other surfactants were added in place of "bis-butyl dimethicone polyglyceryl-3."

In addition, in Comparative Example 8, when "silicone-treated titanium oxide" was dispersed using "bis-butyldimethicone polyglyceryl-3" instead of the hydrophobic treated silica powder of the present invention, it was found that redispersibility was poor.

(Measurement of the oil absorption of oleic acid by hydrophobically treated silica powder)
The oil absorption of oleic acid was measured for the hydrophobic treated silica powder (silicone treated silica) used in the examples, with reference to "JIS-K JIS K 5101-13-1 Japanese Industrial Standards Pigment Test Methods - Part 13: Oil Absorption - Section 1: Refined Linseed Oil Method".

More specifically, 100 g of hydrophobic treated silica powder was weighed out, and the oil absorption of the hydrophobic treated silica powder was measured using olein instead of refined linseed oil.

As a result of the measurement, it was found that the oil absorption of oleic acid of the hydrophobically treated silica powder used in the examples was 240-250 ml/100 g.

(Viscosity Measurement)
The cosmetics of Examples 1 to 3 were measured using a BL type viscometer (VS-A type, manufactured by Shibaura Systems Co., Ltd., 30°C) at 12 rpm and 1 minute using a rotor No. 3. As a result, the viscosity of each of the cosmetics of Examples 1 to 3 was 2000 mPa·s.

<Prescription example>
Formulation examples of the cosmetic composition of the present invention are given below, but the present invention is not limited to these examples.

Formulation example Sunscreen Ingredients Content (mass%)
Water Residual Ethanol 6.0%
Volatile dimethicone 22%
Non-volatile dimethicone 4.0%
Diphenylsiloxyphenyl trimethicone 3.0%
Trifluoroalkyldimethyltrimethylsiloxysilicate/Dimethicone
2.6%
PEG-10 Dimethicone 0.9%
Bisbutyldimethicone polyglyceryl-3 1.0%
Ethylhexyl methoxycinnamate 5.0%
Bisethylhexyloxyphenol methoxyphenyl triazine 0.5%
Fatty acid treated titanium dioxide 1.0%
Fatty acid ester treated zinc oxide 6.0%
Silicone-treated silica 5.0%
Polyhydroxybutyric acid 0.1%
Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) 0.1%
Phenoxyethanol 0.5%
Total 100%

Claims (9)

A liquid oil-based cosmetic composition comprising the following components (a) to (c):
(a) volatile silicone oil 5.0 to 60 mass%;
(b) 3.0 to 10% by mass of hydrophobic treated silica powder;
(c) 0.05 to 5.0 mass% of a polyglycerin-modified silicone represented by the following formula (I):

In formula (I), R ₁ represents a linear or branched alkyl group having 1 to 12 carbon atoms, or a phenyl group; R ₂ represents an alkylene group having 2 to 11 carbon atoms; p is a number from 10 to 120; and q is a number from 1 to 11. The cosmetic preparation according to claim 1, wherein the oil absorption of the hydrophobically treated silica powder with oleic acid is 1.0 ml/g or more. The cosmetic preparation according to claim 1 or 2, wherein the volatile silicone oil is linear dimethicone. (e) The cosmetic preparation according to any one of claims 1 to 3, further comprising an ultraviolet light scattering agent. The cosmetic preparation according to any one of claims 1 to 4, further comprising (f) a film-forming agent. The cosmetic preparation according to any one of claims 1 to 5, which is a water-in-oil type. The cosmetic preparation according to any one of claims 1 to 6, wherein the hydrophobic treated silica powder is a silicone treated silica powder. The cosmetic preparation according to any one of claims 1 to 7, wherein the polyglycerin-modified silicone is bis-butyldimethicone polyglyceryl-3. The cosmetic preparation according to any one of claims 1 to 8 is a redispersible cosmetic preparation that is redispersed by shaking when used.