WO2025105213A1 - Cosmetic containing hydrophobized powder - Google Patents

Abstract

This invention provides a cosmetic having good stability and capable of achieving a high ultraviolet protection effect. This cosmetic contains (A1) a first hydrophobized powder and (B) water, wherein an (A1) component is dispersed in an aqueous phase, and the average particle diameter of secondary particles in the (A1) component in the aqueous phase is 150 nm or less.

Description

Cosmetics containing hydrophobically treated powder

The present invention relates to a cosmetic comprising a hydrophobically treated powder. More specifically, the present invention relates to a cosmetic comprising a hydrophobically treated powder in an aqueous phase, the secondary particles of which have an average diameter of 150 nm or less.

The purpose of sunscreen cosmetics is to block ultraviolet rays in sunlight and protect the skin from the harmful effects of ultraviolet rays. In order to block ultraviolet rays from reaching the skin and obtain a high SPF (Sun Protection Factor) value, it is conceivable to incorporate a high amount of ultraviolet scattering agents, but in that case, the transparency of the base may decrease, the skin may feel burdensome when applied to the skin, or the skin may become white after application.
Cosmetics have been proposed that have a high SPF value while reducing the feeling of strain on the skin by dispersing powders such as ultraviolet scattering agents in an oil phase by a dispersion method using cavitation (Patent Document 1).

Powder made of metal oxides or the like with hydrophobic surfaces is known as an ultraviolet scattering agent. Such powders are usually present in large amounts in the oil phase, and in order to make them exist in the aqueous phase, it is necessary to improve the dispersion state.

International Publication No. 2020/100803

The inventors' research has surprisingly revealed that by dispersing hydrophobically treated powder with an average secondary particle size of 150 nm or less in the aqueous phase of a cosmetic, it is possible to achieve good stability and a high UV protection effect. The present invention is based on these findings.

According to the present invention, the following inventions are provided.
[1] A cosmetic comprising (A1) a first hydrophobized powder and (B) water,
A cosmetic preparation, comprising: an (A1) component dispersed in an aqueous phase; and an average particle size of secondary particles of the (A1) component in the aqueous phase being 150 nm or less.
[2] The cosmetic preparation according to [1], wherein the aqueous phase further comprises (C) a polyether-modified silicone or polyoxyethylene alkyl ether having an HLB of 5 to 18.
[3] (A2) A second hydrophobized powder and (D) an oil component are further included;
The cosmetic preparation according to [1] or [2], wherein the component (A2) is dispersed in an oil phase, and the average particle size of secondary particles of the component (A2) in the oil phase is 150 nm or less.
[4] The cosmetic preparation according to [3], further comprising (E) glycerin modified at both ends with silicone in the oil phase.
[5] The cosmetic according to [3] or [4], wherein the combined amount of the (A1) component and the (A2) component is 30 mass% or less relative to the total amount of the cosmetic.
[6] The cosmetic preparation according to any one of [3] to [5], wherein the blending amount of the (A1) component is 10 to 100 mass% relative to the combined blending amount of the (A1) component and the (A2) component.
[7] The cosmetic preparation according to any one of [1] to [6], which is an oil-in-water emulsion cosmetic preparation or a water-in-oil emulsion cosmetic preparation.
[8] The cosmetic preparation according to any one of [1] to [7], which is a sunscreen cosmetic preparation.
[9] A method for producing the cosmetic composition according to [1],
an aqueous mixture preparation step of mixing the component (A1) with water to prepare an aqueous mixture;
and an aqueous phase dispersion step of passing the aqueous mixture through a throttle passage as a high-pressure fluid of 50 to 200 MPa and dispersing component (A1) in an aqueous phase by cavitation generated in the throttle passage.
[10] An oily mixture preparation step of mixing the (A2) component and an oil to prepare an oily mixture;
The method according to [9], further comprising an oil phase dispersion step of passing the oil mixture through a throttle passage as a high-pressure fluid of 50 to 200 MPa and dispersing the component (A2) in the oil phase by cavitation generated in the throttle passage.

The present invention provides a cosmetic preparation that has good stability and can achieve a high UV protection effect. Furthermore, the cosmetic preparation of the present invention can suppress the decrease in transparency of the base, reduce the burden on the skin, and improve the feel when used.

Description of the Invention

[Cosmetics]
The present invention relates to a cosmetic preparation comprising (A1) a first hydrophobized powder (hereinafter sometimes referred to as component (A1), the same applies to other components) and (B) water. Component (A1) is dispersed in an aqueous phase, and the average particle size of its secondary particles is 150 nm or less, preferably 10 to 130 nm.
One of the features of the cosmetic preparation according to the present invention is that the aggregation of powder particles is greatly suppressed and the secondary particle size of the powder particles is small. The cosmetic preparation according to the present invention includes those in which the powder maintains a dispersed state over a normal storage period, and further includes those in which the powder settles during a normal storage period in the art, but can be redispersed by stirring the cosmetic preparation or shaking the container by a method normal in the art.

The cosmetic preparation according to the present invention may further comprise an oil phase.
Preferably, the cosmetic according to the present invention further comprises (A2) a second hydrophobized powder and (D) an oil component. In this case, the component (A2) is dispersed in the oil phase, and the average particle size of the secondary particles is 150 nm or less, preferably 10 to 130 nm.
In a preferred embodiment of the present invention, the components (A1) and (A2) are dispersed in both the aqueous phase and the oil phase, respectively, with average particle sizes of 150 nm or less.

Regarding the average particle size of the secondary particles of the hydrophobized powder, the average particle size and particle size distribution of the submicron particles dispersed in a liquid can be measured using dynamic light scattering.
The average particle size of the primary particles can be measured by a nitrogen adsorption method.

(A1) First Hydrophobized Powder The (A1) component is a hydrophobized powder, dispersed in the aqueous phase of the cosmetic, and has an average particle size of the secondary particles of 150 nm or less. The hydrophobized powder is preferably a hydrophobized metal oxide powder. The hydrophobized powder is preferably a powder having an ultraviolet scattering function, i.e., an ultraviolet scattering agent. The average primary particle size of the hydrophobized powder is generally 10 nm or more and 100 nm or less. Specific examples of hydrophobized metal oxides include titanium oxide, zinc oxide, cerium oxide, talc, silica, mica, sericite, kaolin, mica titanium, black iron oxide, yellow iron oxide, red ocher, ultramarine, iron blue, chromium oxide, chromium hydroxide, etc. Among these, titanium oxide and zinc oxide are preferred because of their high ultraviolet scattering function. In addition, a composite powder in which particles made of a material other than titanium oxide are coated with titanium oxide can also be used.

The hydrophobic treatment applied to the powder may be a treatment that introduces hydrophobic groups to the particle surface or forms a coating of a hydrophobic substance. Specifically, the hydrophobic treatment may be a wet method using a solvent, a gas phase method, a mechanochemical method, or the like. In addition, as a treatment agent for the hydrophobic treatment, silicones such as methylhydrogenpolysiloxane, dimethylpolysiloxane, and triethoxycaprylylsilane, dextrin fatty acid esters, higher fatty acids, higher alcohols, fatty acid esters, metal soaps, alkyl phosphate ethers, fluorine compounds, or hydrocarbons such as squalane and paraffin, etc. can be used. Since component (A1) is dispersed in the aqueous phase, silicone treatment is preferred as the hydrophobic treatment.

The (A1) component may be used alone or in combination with two or more other components. The amount of the (A1) component is preferably 0.1 to 30% by mass, more preferably 0.5 to 10% by mass, and even more preferably 1 to 3% by mass, based on the total amount of the cosmetic.

(A2) Second hydrophobized powder The cosmetic according to the present invention may further contain (A2) a second hydrophobized powder. The (A2) component is a hydrophobized powder that is dispersed in the oil phase in the cosmetic, and the average particle size of the secondary particles is 150 nm or less. The (A1) component and the (A2) component may be the same or different. The preferred (A2) component is the same as the above-mentioned (A1) component.

The (A2) component may be used alone or in combination with two or more other components. The amount of the (A2) component is preferably 0.5 to 15% by mass, and more preferably 1 to 10% by mass, based on the total amount of the cosmetic.

The combined amount of the components (A1) and (A2) is preferably 30% by mass or less, more preferably 1 to 20% by mass, and even more preferably 2 to 12% by mass, relative to the total amount of the cosmetic.
In the cosmetic preparation according to the present invention, aggregation of the hydrophobized powder is suppressed and the secondary particle size is small, so that a high UV protection effect can be achieved with a smaller amount than the amount of powder normally blended. By suppressing the amount of hydrophobized powder blended in the cosmetic preparation, the decrease in the transparency of the base can be suppressed and the feeling of use can be improved.

The cosmetic preparation according to the present invention comprises water (B). As the water, water used in cosmetics, quasi-drugs, etc., can be used, such as purified water, ion-exchanged water, tap water, etc.
The blending amount of water is preferably 10 to 35% by mass, more preferably 10 to 25% by mass, based on the total amount of the cosmetic according to the present invention.

(C) Polyether-modified silicone or polyoxyethylene alkyl ether The cosmetic preparation according to the present invention preferably further comprises (C) a polyether-modified silicone or a polyoxyethylene alkyl ether in the aqueous phase. Component (C) can improve the dispersion state of component (A1) in the aqueous phase.
The HLB (hydrophile-lipophile balance) of component (C) is 5 to 18, more preferably 5 to 16, and even more preferably 6 to 10. Within this range, the initial dispersibility and dispersion stability of component (A1) in the aqueous phase can be improved. In the present invention, the HLB value is a value calculated by the Griffin method.

The component (C) is preferably a polyether-modified silicone. The polyether-modified silicone is preferably a dimethicone having a PEG chain and/or a PPG chain, more preferably a dimethicone having a PEG chain. The average number of moles of alkylene oxide added may be 8 or more and 40 or less. It may also be an alkyl ether of dimethicone having a PEG and/or PPG chain terminal. A preferred example of a polyether-modified silicone is PEG-12 dimethicone. The silicone chain of the polyether-modified silicone may be either a straight chain or a branched chain, but is preferably a straight chain. It may be a polyether-modified alkyl-modified silicone further having an alkyl side chain, but is preferably unalkyl-modified.

The (C) component may be blended in one or more types. The blended amount of the (C) component is preferably 0.01 to 10 mass % relative to the total amount of the cosmetic, more preferably 0.05 to 5 mass %, and even more preferably 0.05 to 1 mass %.

The cosmetic composition according to the present invention may further comprise an oil component (D). Examples of the oil component (D) include silicone oils, hydrocarbon oils, higher fatty acids, higher alcohols, ester oils, and liquid fats and oils, and preferably silicone oils, hydrocarbon oils, and ester oils.
Examples of silicone oils include dimethicone, methylphenylpolysiloxane, methylhydrogenpolysiloxane, methicone hexamethyldisiloxane, octamethyltrisiloxane, decamethyltetrasiloxane, hexadecamethylheptasiloxane, and caprylyl methicone.
Examples of hydrocarbon oils include isododecane, isohexadecane, isoparaffin, liquid paraffin, ozokerite, squalane, pristane, paraffin, ceresin, squalene, petrolatum, and microcrystalline wax.
Examples of the ester oil include octyl octanoate, nonyl nonanoate, cetyl octanoate, isopropyl myristate, octyldodecyl myristate, isopropyl palmitate, ethylhexyl palmitate, butyl stearate, hexyl laurate, myristyl myristate, decyl oleate, hexyldecyl dimethyloctanoate, cetyl lactate, myristyl lactate, lanolin acetate, isocetyl stearate, isocetyl isostearate, cholesteryl 12-hydroxystearate, ethylene glycol di-2-ethylhexanoate, dipentaerythritol fatty acid ester, N-alkyl glycol monoisostearate, neopentyl glycol dicaprate, tripropylene glycol pivalate, diisostearyl malate, glycerin di-2-heptylundecanoate, glycerin diisostearate, trimethylolpropane tri-2-ethylhexanoate, triisostearate trimethylolpropane, pentaerythritol tetra-2-ethylhexanoate, glycerin tri-2-ethylhexanoate, glycerin trioctanoate, glycerin triisopalmitate, trimethylolpropane triisostearate, cetyl 2-ethylhexanoate-2-ethylhexyl palmitate, glycerin trimyristate, tri-2-heptylundecanoate glyceride, castor oil fatty acid methyl ester, oleyl oleate, acetoglyceride, Examples of the glyceryl ester include 2-heptylundecyl palmitate, diisobutyl adipate, N-lauroyl-L-glutamic acid-2-octyldodecyl ester, di-2-heptylundecyl adipate, ethyl laurate, di-2-ethylhexyl sebacate, 2-hexyldecyl myristate, 2-hexyldecyl palmitate, 2-hexyldecyl adipate, diisopropyl sebacate, 2-ethylhexyl succinate, triethyl citrate, and cetyl ethylhexanoate.

The (D) component may be blended in one or more types. The blended amount of the (D) component is preferably 10 to 80 mass % relative to the total amount of the cosmetic, and more preferably 20 to 60 mass %.

(E) Glycerin modified at both ends with silicone The cosmetic preparation according to the present invention may further comprise (E) glycerin modified at both ends with silicone. Component (E) can improve the dispersion state of component (A2) in the oil phase.
The component (E) is preferably represented by formula (1).
During the ceremony,
R ¹ is a C _1-12 alkyl group or a phenyl group, preferably a methyl group;
^R2 is a _C2-11 alkylene group, preferably a trimethylene group;
m is 10 to 120;
n is 1 to 11.
The alkyl and alkylene groups can be straight-chained or branched.
The weight average molecular weight of the component (E) is preferably 2,000 to 30,000. The weight average molecular weight can be calculated, for example, by gel permeation chromatography using polystyrene standards.
Examples of component (E) include bisbutyldimethicone polyglyceryl-3.

The component (E) may be used alone or in combination with two or more other components. The amount of component (E) used is preferably 0.1 to 20% by mass, and more preferably 0.5 to 10% by mass, based on the total amount of the cosmetic.

The cosmetic preparation according to the present invention may contain ingredients other than those mentioned above that are commonly used in cosmetics, provided that the ingredients do not impair the effects of the present invention. Examples of these ingredients include thickeners, moisturizers, UV absorbers, medicines, stabilizers, pH adjusters, preservatives, pigments, dyes, surfactants, powdered ingredients, fragrances, etc.

[Production method of cosmetics]
The method for producing a cosmetic according to the present invention is not particularly limited, but in a preferred embodiment, the method comprises the following steps:
The method comprises: (I) an aqueous mixture preparation step of mixing component (A1) and water to prepare an aqueous mixture; and (II) an aqueous phase dispersion step of passing the aqueous mixture as a high-pressure fluid of 50 to 200 MPa through a throttle passage and dispersing component (A1) in an aqueous phase by cavitation generated in the throttle passage.
The method for producing a cosmetic preparation according to the present invention can further include the following steps: (III) an oily mixture preparation step of mixing the (A2) component and an oil to prepare an oily mixture; and (IV) an oil phase dispersion step of passing the oily mixture as a high-pressure fluid of 50 to 200 MPa through a throttle flow path and dispersing the (A2) component in an oil phase by cavitation generated in the throttle flow path.

(I) Aqueous mixture preparation step In this step, water as a dispersion medium, component (A1), and optional components as required are mixed while stirring to prepare an aqueous mixture. In this step, it is preferable to include component (C) as an optional component for improving dispersibility. Other optional components include, for example, moisturizers, stabilizers, preservatives, thickeners, etc.

(II) Aqueous Phase Dispersion Step In this step, the aqueous mixture prepared in step (I) is homogenized based on the principle of cavitation to prepare an aqueous phase dispersion. Cavitation is a physical phenomenon in which bubbles are generated and disappear in a short time due to pressure differences in a liquid flow. Specifically, the mixture obtained in step (I) is given a flow velocity, and the liquid is passed through a throttle channel to generate fine bubbles due to cavitation, and the aqueous phase dispersion is obtained by the impact force. The flow velocity is given by an ultra-high pressure flow of 50 to 200 MPa. If it is less than 50, the dispersion effect may be insufficient, which is not preferable.

(III) Oily mixture preparation step In this step, the oil as a dispersion medium, the (A2) component, and any other component as necessary are mixed while stirring to prepare an oily mixture. In this step, it is preferable to include the (E) component as the optional component for improving dispersibility. Other optional components include, for example, moisturizers, stabilizers, preservatives, thickeners, etc., but it is also a preferred embodiment to not include any other optional components than the (E) component.

(IV) Oil phase dispersion step In this step, the oil mixture prepared in step (III) is homogenized based on the principle of cavitation to prepare an oil phase dispersion. The method of homogenization by cavitation is the same as that in step (II).

The prepared aqueous phase dispersion, and if necessary, the oil phase dispersion, can be used to manufacture cosmetics in accordance with conventional manufacturing methods.

The cosmetic according to the present invention may be an oil-in-water emulsion cosmetic, a water-in-oil emulsion cosmetic, or an unemulsified aqueous cosmetic, but is preferably an oil-in-water emulsion cosmetic or a water-in-oil emulsion cosmetic, and more preferably a water-in-oil emulsion cosmetic.

The cosmetics in this specification include cosmetics with enhanced ultraviolet absorbing function, basic cosmetics (foundation, base makeup, etc.), makeup cosmetics (eye shadow, blush, etc.), and of course sunscreen cosmetics (sunscreen compositions). The cosmetics according to the present invention can achieve a high ultraviolet ray protection effect and have an excellent feeling when used, so they are preferably sunscreen cosmetics.

The present invention will be specifically explained based on the following examples, but the present invention is not limited to these examples. The blend amounts are shown as mass % of the total amount unless otherwise specified.

[Aqueous phase dispersion W1 to W6]
Using the compositions shown in Table 1, aqueous phase dispersions W1 to W5 were prepared by a dispersion method using cavitation, and aqueous phase dispersion W6 was prepared by a dispersion method using a homomixer.
In Table 1,
(*1): "STR 100C-LP", manufactured by Sakai Chemical Industry Co., Ltd., average primary particle size 15 nm.

[Oil phase dispersions O1 and O2]
Using the compositions shown in Table 2, an aqueous phase dispersion of O1 was prepared by a dispersion method using cavitation, and an aqueous phase dispersion of O2 was prepared by a dispersion method using a homomixer.
In Table 2,
(*2): "ST-485SA", manufactured by Titan Kogyo Co., Ltd., average primary particle size 8 nm,
(*3): “MSY-MZ500”, manufactured by Teika Corporation, average primary particle size 25 nm.

[Average secondary particle size]
The average secondary particle size of the dispersion prepared above was measured by dynamic scattering method, and the results are shown in Tables 1 and 2.

[Evaluation of UV protection effect]
The SPF value of the dispersion prepared above was measured using an SPF measuring device "SPF MASTER" (Shiseido), and the UV protection effect was evaluated according to the following criteria. The results are shown in Tables 1 and 2.
A: SPF 50 or more B: SPF 30 or more to less than 50 C: SPF less than 30

[Stability evaluation]
The appearance of the dispersion prepared above was visually observed immediately after preparation and after storage at room temperature for 10 days, and was evaluated according to the following criteria. The results are shown in Tables 1 and 2.
A: No precipitation or aggregation was observed, and the composition was extremely stable.
B: No significant precipitation or aggregation was observed and the mixture was stable.
C: Precipitation or aggregation was observed over time.

[Examples 1 to 6 and Comparative Examples 1 and 2]
Using the dispersions prepared above, water-in-oil emulsion cosmetics of Examples 1 to 6 and Comparative Examples 1 and 2 were prepared according to the formulations shown in Table 3.
In Table 3,
(*4): “SA-SB-300”, manufactured by Miyoshi Chemicals Co., Ltd., average primary particle size 5 μm.

The evaluation of UV protection effect and stability were performed using the same method as the measurement method for the dispersion described above, using the cosmetics prepared in Table 3.

Claims (10)

A cosmetic comprising: (A1) a first hydrophobized powder; and (B) water,
A cosmetic preparation, comprising: an (A1) component dispersed in an aqueous phase; and an average particle size of secondary particles of the (A1) component in the aqueous phase being 150 nm or less. The cosmetic preparation according to claim 1, wherein the aqueous phase further comprises (C) a polyether-modified silicone or polyoxyethylene alkyl ether having an HLB of 5 to 18. (A2) a second hydrophobized powder; and (D) an oil component,
2. The cosmetic preparation according to claim 1, wherein the component (A2) is dispersed in an oil phase, and the average particle size of secondary particles of the component (A2) in the oil phase is 150 nm or less. The cosmetic preparation according to claim 3, further comprising (E) glycerin modified at both ends with silicone in the oil phase. The cosmetic according to claim 1, wherein the combined amount of components (A1) and (A2) is 30% by mass or less based on the total amount of the cosmetic. The cosmetic preparation according to claim 3, in which the amount of component (A1) is 10 to 100 mass % of the total amount of components (A1) and (A2). The cosmetic according to claim 1, which is an oil-in-water emulsion cosmetic or a water-in-oil emulsion cosmetic. The cosmetic product according to claim 1, which is a sunscreen cosmetic product. A method for producing the cosmetic preparation according to claim 1, comprising the steps of:
an aqueous mixture preparation step of mixing the component (A1) with water to prepare an aqueous mixture;
and an aqueous phase dispersion step of passing the aqueous mixture through a throttle passage as a high-pressure fluid of 50 to 200 MPa and dispersing component (A1) in an aqueous phase by cavitation generated in the throttle passage. (A2) An oily mixture preparation step of mixing the component and an oil to prepare an oily mixture;
The method according to claim 9, further comprising an oil phase dispersion step of passing the oily mixture through a throttle passage as a high-pressure fluid of 50 to 200 MPa and dispersing the component (A2) in the oil phase by cavitation generated in the throttle passage.