JP2020105177A - External preparation for skin - Google Patents

Abstract

To provide an external preparation for skin having an excellent infrared-ray protection effect, hardly causes whitening when applied to the skin, gives natural appearance and has good makeup application after application and to provide a method for protecting the skin from infrared rays.SOLUTION: There are provided: [1] an external preparation for skin which comprises a plate-like metal oxide (A) having a thickness of 30 to 360 nm and a nonvolatile oil (B), wherein the mass ratio [(A)/(B)] is 0.05 or more and 5 or less; and [2] a method for protecting the skin from infrared rays by applying the external preparation for skin described in the above [1] to the skin.SELECTED DRAWING: None

Description

The present invention relates to an external preparation for skin and an infrared protection method for skin.

From the viewpoint of skin protection against sunlight, UV protection cosmetics such as sunscreen cosmetics are known. On the other hand, in recent years, with increasing awareness of health, an external preparation for skin having a protective function against infrared rays is required.
Regarding a skin external preparation having an infrared protection function, for example, Patent Document 1 discloses a technique relating to an inhibitor that prevents infrared rays from reaching a tissue deeper than the skin tissue and prevents damage to those tissues due to infrared rays. , A near-infrared damage-preventing agent for living tissue containing an infrared ray transmission blocking agent composed of titanium oxide powder and zinc oxide powder is disclosed. Further, Patent Document 2 discloses a near-infrared protective cosmetic composition composed of titanium oxide powder and zinc oxide powder, which has both an excellent near-infrared protective effect and high transparency.

International Publication No. 2009/017104 JP, 2017-95361, A

However, for skin protection, a skin external preparation having an improved infrared protection function is desired. Furthermore, among the external skin preparations, skin cosmetics are required to have a natural appearance when they are applied to the skin and to have a natural appearance and to have good cosmetic paste after application and to be excellent in usability.
An object of the present invention is to provide an infrared protection method for skin, which is excellent in infrared protection effect, has a natural appearance when it is applied to the skin, and has a natural appearance. is there.

The present inventors have found that an external preparation for skin containing a predetermined shape of a metal oxide and a non-volatile oil can solve the above problems.
That is, the present invention relates to the following [1] and [2].
[1] A plate-like metal oxide (A) having a thickness of 30 nm or more and 360 nm or less and an aspect ratio of 50 or more and 300 or less, and a non-volatile oil (B) are contained, and a mass ratio [(A)/(B) is included. ] The external preparation for skin which is 0.05 or more and 5 or less.
[2] A method for protecting the skin from infrared rays by applying the external preparation for skin according to the above [1] to the skin.

The external preparation for skin of the present invention has an excellent effect of protecting against infrared rays, provides a high thermal barrier feeling, is less likely to become white when applied to the skin, has a natural appearance, and has a good cosmetic paste after application, and also has a feeling of use. Since it is excellent, it is useful as a skin cosmetic, for example.

[Skin external preparation]
The external preparation for skin of the present invention contains a plate-like metal oxide (A) having a thickness of 30 nm or more and 360 nm or less and an aspect ratio of 50 or more and 300 or less, and a nonvolatile oil (B), and has a mass ratio [(A )/(B)] is 0.05 or more and 5 or less.

In the present invention, the thickness of the plate-shaped metal oxide means the shortest axial length in the plate-shaped metal oxide particles.
Further, in the present invention, the infrared ray means an electromagnetic wave having a wavelength of 780 nm to 1 mm. Of these, the external preparation for skin of the present invention is particularly excellent in the near-infrared ray protective effect at a wavelength of 780 nm to 2500 nm. As a result, it is possible to suppress an increase in the skin temperature due to the irradiation of sunlight and obtain a high thermal insulation feeling.
In the present specification, the infrared protection rate at a wavelength of 1500 nm is used as an index for the infrared protection effect.

The dosage form of the skin external preparation of the present invention is not particularly limited, but it is preferably liquid, gel, or cream from the viewpoint of easy application to the skin. The external preparation for skin may be in the form of an emulsion composition, and the emulsion composition may be either an oil-in-water emulsion composition or a water-in-oil emulsion composition.
The external preparation for skin of the present invention may be a skin cosmetic such as a lotion, a cream, a milky lotion, a beauty essence, a suntan, and a makeup base cosmetic as well as an external skin external preparation for infrared protection. A skin cosmetic is preferred because it is less likely to whiten when applied to the skin and the appearance is natural and the makeup paste after application is good.

<Plate metal oxide (A)>
The external preparation for skin of the present invention contains a plate-like metal oxide (A) having a thickness of 30 nm or more and 360 nm or less and an aspect ratio of 50 or more and 300 or less.
Since the external preparation for skin of the present invention contains a plate-like metal oxide having a predetermined thickness as the component (A), it has an excellent infrared protection effect, a high heat shield effect is obtained, and when applied to the skin. Also, it does not become white easily and looks natural.

It is known that in the external preparation for skin containing inorganic particles such as titanium oxide, the one having a larger particle size has a higher infrared protection effect. However, there is a limit to the improvement of the infrared protection effect only by using the inorganic particles having a large particle size. Further, for example, when spherical inorganic particles having a particle diameter larger than the wavelength of visible light are mixed with a skin external preparation, when applied to the skin, white light occurs due to light scattering of visible light on the particle surface. It had the drawback that it was easy and inferior in natural appearance. Therefore, it is difficult to achieve both the infrared protection effect and the natural appearance when applied to the skin by merely controlling the particle size of the inorganic particles used.

The present inventors use a plate-shaped metal oxide having a predetermined thickness as the component (A) in the external preparation for skin while selectively increasing the reflectance of light in the infrared region by the light interference effect. It has been found that the reflectance of light in the visible region can be reduced, whereby both the infrared protection effect and the natural appearance when applied to the skin can be achieved.
When the thickness of the component (A) is in the predetermined range (30 nm or more and 360 nm or less), the reflectance of light observed on the upper surface side of the skin when the external preparation containing the component (A) is applied to the skin. However, due to the interference effect of light, it becomes higher for light having a wavelength in the infrared region and becomes lower for light having a wavelength in the visible region. Therefore, it is possible to achieve both a high infrared protection effect and a natural appearance when applied to the skin.
Furthermore, by using the above-mentioned predetermined component (A), the makeup paste after application becomes good.

The thickness of the component (A) is 30 nm or more, and preferably 50 nm or more, from the viewpoint of obtaining an excellent infrared protection effect by the above-mentioned action mechanism and the viewpoint of the natural appearance when applied to the skin. , More preferably 60 nm or more, still more preferably 80 nm or more, even more preferably 105 nm or more, still more preferably 125 nm or more. In addition, the thickness of the component (A) is 360 nm or less, preferably from the viewpoint of obtaining an excellent infrared protection effect, the natural appearance when applied to the skin, and the viewpoint of makeup paste after application. It is 330 nm or less, more preferably 310 nm or less, still more preferably 280 nm or less, still more preferably 270 nm or less. The specific range of the thickness of the component (A) is 30 nm or more and 360 nm or less from the viewpoint of obtaining an excellent infrared protection effect, the natural appearance when applied to the skin, and the viewpoint of makeup paste after application. Yes, preferably 50 nm or more and 330 nm or less, more preferably 60 nm or more and 310 nm or less, still more preferably 60 nm or more and 280 nm or less, still more preferably 80 nm or more and 280 nm or less, still more preferably 105 nm or more and 270 nm or less. And more preferably 125 nm or more and 270 nm or less.
The thickness of the component (A) can be determined from an image observed with a scanning electron microscope (SEM). Specifically, the component (A) is observed with an SEM under an observation magnification of 10,000 times, the thickness of 50 particles in the observed image is measured, and the average value of the thickness per number is calculated. It is obtained by calculating. The thickness of the component (A) can be specifically measured by the method described in Examples.

In addition, the aspect ratio of the component (A) is 50 or more, preferably 55 or more, from the viewpoint of obtaining an excellent infrared protection effect and the naturalness of appearance when applied to the skin, and also excellent. From the viewpoint of obtaining an infrared protection effect, the natural appearance when applied to the skin, and the viewpoint of makeup paste after application, it is 300 or less, preferably 230 or less, more preferably 200 or less, It is more preferably 140 or less, still more preferably 125 or less, still more preferably 120 or less. The specific range of the aspect ratio of the component (A) is 50 or more and 300 or less from the viewpoint of obtaining an excellent infrared protection effect, the natural appearance when applied to the skin, and the viewpoint of makeup paste after application. Yes, preferably 50 or more and 230 or less, more preferably 55 or more and 230 or less, still more preferably 55 or more and 200 or less, still more preferably 55 or more and 140 or less, still more preferably 55 or more and 125 or less. And more preferably 55 or more and 120 or less.
Regarding the aspect ratio of the component (A), SEM observation was performed under the same conditions as described above, and the shortest axis length (thickness) and the longest axis length (major axis) of 50 particles in the observed image. Is calculated, the aspect ratio (major axis/thickness) of each particle is calculated, and the average value is obtained. The aspect ratio of the plate-shaped metal oxide can be specifically measured by the method described in Examples.

The metal oxide constituting the component (A) is a material having a high refractive index so that a higher optical interference effect can be obtained. From this viewpoint, examples of preferable metal oxides constituting the component (A) include titanium oxide, zinc oxide, zirconium oxide, iron oxide, aluminum oxide, and cerium oxide. Among these, at least one selected from the group consisting of titanium oxide and zinc oxide is preferable, and titanium oxide is more preferable. That is, the component (A) is preferably at least one selected from the group consisting of plate-shaped titanium oxide and plate-shaped zinc oxide, and more preferably plate-shaped titanium oxide.
The crystal structure of titanium oxide may be any of rutile type, anatase type and amorphous, but the rutile type is preferable from the viewpoint of obtaining an excellent infrared protection effect and a real feeling of heat shield.

The plate-like metal oxide of the component (A) may not be surface-treated, and may be subjected to a surface treatment such as a hydrophobic treatment by a known method, if necessary, in order to enhance the dispersibility in the external preparation for skin. It may be a thing. In addition, the plate-like metal oxide of the component (A) is distinguished from those in which the surface of particles other than the metal oxide is surface-treated with the metal oxide.

Examples of the surface treatment agent used for the surface treatment of the component (A) include silicone; alkylalkoxysilanes; fluorine-containing compounds such as perfluoroalkyl phosphates and perfluoroalcohols; amino acids such as N-acylglutamic acid; and lecithin; Metal soap; fatty acids such as stearic acid; alkyl phosphates and the like. Among these, at least one selected from the group consisting of silicone and alkylalkoxysilane is preferable.
Silicone as a surface treatment agent is not particularly limited, but for example, methylpolysiloxane, dimethylpolysiloxane, methylphenylpolysiloxane, methylhydrogenpolysiloxane, methylcyclopolysiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, Dodecamethylcyclohexasiloxane, octamethyltrisiloxane, tetradecamethylhexasiloxane, dimethylsiloxane/methyl(polyoxyethylene)siloxane/methyl(polyoxypropylene)siloxane copolymer, dimethylsiloxane/methyl(polyoxyethylene)siloxane Polymers, dimethyl siloxane/methyl (polyoxypropylene) siloxane copolymers, dimethyl siloxane/methyl cetyloxy siloxane copolymers, dimethyl siloxane/methyl stearoxy siloxane copolymers, (alkyl acrylate/dimethicone) copolymers, etc. Mention may be made of silicone oils.
As the alkylalkoxysilane as the surface treatment agent, those having a branched or linear alkyl group having 6 to 20 carbon atoms are preferable, and particularly, octyltriethoxysilane and octyltrimethoxysilane can be mentioned.
From the viewpoint of improving the infrared protection effect, one or more selected from the group consisting of methylpolysiloxane, dimethylpolysiloxane, methylhydrogenpolysiloxane, (alkyl acrylate/dimethicone) copolymer, and octyltriethoxysilane are preferable.
When the component (A) is surface-treated, the amount of the surface-treating agent coated is, relative to the total amount of the plate-like metal oxide of the component (A), from the viewpoint of enhancing dispersibility in the external skin preparation. 1 mass% or more and 9 mass% or less are preferable, and 2 mass% or more and 8 mass% or less are more preferable.

The content of the component (A) in the external preparation for skin is preferably 1% by mass or more, more preferably 3% by mass or more, and further preferably 6% by mass or more, from the viewpoint of obtaining an excellent infrared protection effect. And more preferably 8% by mass or more. In addition, the content of the component (A) in the external preparation for skin is preferably 35% by mass or less, and more preferably 25, from the viewpoint of appearance naturalness when applied to the skin and makeup paste after application. It is at most mass%, more preferably at most 17 mass%, even more preferably at most 12 mass%.
The specific range of the content of the component (A) in the external preparation for skin is preferably 1 mass from the viewpoint of achieving both the infrared protection effect, the natural appearance when applied to the skin, and the makeup paste after application. % To 35% by mass, more preferably 3% to 25% by mass, still more preferably 6% to 17% by mass, still more preferably 8% to 12% by mass. is there.

A commercially available plate-shaped metal oxide can also be used as the component (A). Examples of commercially available plate-shaped titanium oxide include "Feathereve PT-9001K", "Feathereve PT-7001K", "Feathereve PT-7401K", "Feathereve PT-7801K", and "Feathereve PT-7901K" manufactured by CQV. ..

(Nonvolatile oil (B))
The external preparation for skin of the present invention contains the non-volatile oil (B) from the viewpoint of obtaining an excellent infrared protection effect, the natural appearance when applied to the skin, and the viewpoint of makeup paste after application. The non-volatile oil is one having an evaporation amount of less than 20% at 25° C. for 6 hours, which is measured by the following method (1).
Method (1): A filter paper having a diameter of 90 mm is put in a glass dish having a diameter of 120 mm, 1 g of the sample is put on the filter paper, and the sample is stored in a room (25° C.) at 65% RH. Then, the residue of the sample after 6 hours is measured, and the evaporation amount is calculated.

The component (B) is preferably liquid at 25° C. under 1 atm. More specifically, the component (B) has a viscosity at 25° C. of preferably 500 mPa·s or less, more preferably 300 mPa·s or less, further preferably 100 mPa·s or less, and even more preferably It is 50 mPa·s or less, preferably 5 mPa·s or more.
The viscosity was measured using a B-type viscometer "TVB-10" (manufactured by Toki Sangyo Co., Ltd.), and the rotor No. It can be measured under conditions of 1, 25° C., 60 rpm, and 1 minute.

Specific examples of the component (B) are non-volatile oils that are liquid at 25° C., and include, for example, one or more selected from the group consisting of ester oils, silicone oils, hydrocarbon oils, higher fatty acids, and higher alcohols. To be

Examples of the non-volatile liquid ester oils include isononyl isononanoate, isotridecyl isononanoate, isopropyl myristate, isocetyl myristate, octyldodecyl myristate, isopropyl palmitate, ethylhexyl palmitate, 2-hexyldecyl palmitate, and tri-2. -Glyceryl ethylhexanoate, di2-ethylhexyl sebacate, diisopropyl sebacate, tri(caprylic acid/capric acid) glyceryl, diisostearyl malate, diethylene glycol dicaprate, neopentyl glycol dicaprate, neo di2-ethylhexanoate One or more selected from the group consisting of pentyl glycol and alkyl benzoates such as alkyl benzoates (C12 to C15).

Among the above, a monoester of a fatty acid having 12 or more and 18 or less carbon atoms and a branched alcohol having 2 or more and 22 or less carbon atoms from the viewpoint of the natural appearance when applied to the skin, the cosmetic paste after application, and the suppression of stickiness. A triester of a branched fatty acid having 6 to 18 carbon atoms and glycerin, a diester of a dicarboxylic acid having 2 to 18 carbon atoms and a branched alcohol having 2 to 18 carbon atoms, a fatty acid having 6 to 18 carbon atoms and carbon A diester with a branched dialcohol having a number of 2 or more and 10 or less, an alkyl benzoate (C12 to C15) (for example, Finsolve TN; manufactured by Innospec Active Chemicals LLC), and the like are preferable, and specifically, isopropyl myristate, isocetyl myristate, myristin. Octyldodecyl acid salt, isopropyl palmitate, ethylhexyl palmitate, 2-hexyldecyl palmitate, glyceryl tri-2-ethylhexanoate, diisopropyl sebacate, di2-ethylhexyl sebacate, diisostearyl malate, di-2-ethylhexanoic acid One or more selected from the group consisting of neopentyl glycol, neopentyl glycol dicaprate, and alkyl benzoate (C12 to C15) is more preferable, and selected from the group consisting of isopropyl palmitate and alkyl benzoate (C12 to C15). One or more is more preferable.

As the non-volatile liquid silicone oil, methyl polysiloxane is preferable from the viewpoint of suppressing stickiness when applied to the skin, and methyl polysiloxane having a viscosity at 25° C. of 20 mPa·s or less is more preferable.

Examples of the non-volatile liquid hydrocarbon oil include liquid paraffin, light liquid isoparaffin such as hydrogenated polyisobutene, heavy liquid isoparaffin, liquid ozokerite, squalane, pristane, squalene, and isohexadecane. Among these, from the viewpoint of suppressing stickiness when applied to the skin, one or more kinds selected from the group consisting of light liquid isoparaffin and isohexadecane are preferable, and light liquid isoparaffin is more preferable.

Examples of the non-volatile liquid higher fatty acid include fatty acids having 12 to 22 carbon atoms, and specific examples thereof include oleic acid, isostearic acid, linoleic acid, and linoleic acid.
Examples of the non-volatile liquid higher alcohols include alcohols having 12 or more and 28 or less carbon atoms, and specific examples thereof include oleyl alcohol, 2-decyltetradecinol, dodecanol, isostearyl alcohol, octyldodecanol and the like. Can be mentioned.

Component (B) is one or more of non-volatile oils that are liquid at 25° C., preferably selected from the group consisting of ester oils, silicone oils and hydrocarbon oils, from the viewpoint of suppressing stickiness when applied to the skin. More preferably, it is at least one selected from the group consisting of isopropyl palmitate, alkyl benzoate (C12 to C15), methyl polysiloxane, and light liquid isoparaffin, and it is more preferable to contain methyl polysiloxane.

In the external preparation for skin of the present invention, the mass ratio [(A)/(B)] is from the viewpoint of obtaining an excellent infrared protection effect, the natural appearance when applied to the skin, and the viewpoint of makeup paste after application. Therefore, it is preferably 0.05 or more, more preferably 0.1 or more, still more preferably 0.2 or more, still more preferably 0.26 or more, and still more preferably 0.3 or more. Is. The mass ratio [(A)/(B)] is preferably 5 or less, more preferably 2 or less from the viewpoint of the natural appearance when applied to the skin and the viewpoint of makeup paste after application. , More preferably 0.75 or less, still more preferably 0.5 or less, still more preferably 0.45 or less. The specific range of the mass ratio [(A)/(B)] in the external preparation for the skin makes an excellent infrared protection effect compatible with the natural appearance when applied to the skin and the makeup paste after application. From the viewpoint, it is preferably 0.05 or more and 5 or less, more preferably 0.1 or more and 2 or less, more preferably 0.1 or more and 0.75 or less, and still more preferably 0.2 or more and 0.5 or less. Or less, more preferably 0.26 or more and 0.45 or less, and still more preferably 0.3 or more and 0.45 or less.

The content of the component (B) in the external preparation for skin of the present invention is not particularly limited as long as the mass ratio [(A)/(B)] is an amount of 0.05 or more and 5 or less. From the viewpoint of the protective effect, the natural appearance when applied to the skin, and the makeup paste after application, it is preferably 1% by mass or more, more preferably 5% by mass or more, further preferably 15% by mass. Or more, more preferably 20% by mass or more, still more preferably 25% by mass or more, still more preferably 28% by mass or more, and an excellent infrared protection effect, and makeup after application. From the viewpoint of glue, the content is preferably 45% by mass or less, more preferably 38% by mass or less, still more preferably 35% by mass or less, still more preferably 32% by mass or less. The specific range of the content of the component (B) in the external preparation for skin is preferably from the viewpoint of achieving both an excellent infrared protection effect, and the natural appearance when applied to the skin and the cosmetic paste after application. 1 mass% or more and 45 mass% or less, more preferably 5 mass% or more and 45 mass% or less, further preferably 15 mass% or more and 38 mass% or less, and still more preferably 20 mass% or more and 38 mass% or less. Or less, more preferably 25% by mass or more and 35% by mass or less, still more preferably 28% by mass or more and 32% by mass or less.

When the external preparation for skin of the present invention is a water-in-oil emulsion composition, the content of component (B) is preferably 10% by mass or more, and more preferably 15% by mass, from the viewpoint of being a water-in-oil type. % Or more, and more preferably 18% by mass or more. In addition, the upper limit of the content of the component (B) in the water-in-oil emulsion composition is preferably 60% by mass or less, more preferably 40% by mass or less, and further preferably from the viewpoint of emulsion stability. Is 30% by mass or less.
When the external preparation for skin of the present invention is an oil-in-water emulsion composition, the content of the component (B) is preferably 30% by mass or less, and more preferably 20% by mass, from the viewpoint of being an oil-in-water type. It is below, and more preferably 10% by mass or less. Further, the lower limit of the content of the component (B) in the oil-in-water emulsion composition is preferably 1% by mass or more, more preferably 3% by mass or more, and further preferably from the viewpoint of emulsion stability. It is 5 mass% or more.

From the viewpoint of obtaining an excellent infrared protection effect, the natural appearance when applied to the skin, and the viewpoint of makeup paste after application, the total content of the components (A) and (B) in the external preparation for skin is preferably Is 2% by mass or more, more preferably 10% by mass or more, further preferably 20% by mass or more, even more preferably 30% by mass or more, still more preferably 35% by mass or more, and the upper limit is 100% by mass.

(Volatile oil (B)')
The external preparation for skin of the present invention can further contain a volatile oil as the component (B)′. The volatile oil refers to one having an evaporation amount of 20% or more at 25° C. for 6 hours, which is measured by the following method (1).
Method (1): A filter paper having a diameter of 90 mm is put in a glass dish having a diameter of 120 mm, 1 g of the sample is put on the filter paper, and the sample is stored in a room (25° C.) at 65% RH. Then, the residue of the sample after 6 hours is measured, and the evaporation amount is calculated.

The component (B)′ is preferably a volatile silicone oil from the viewpoint of suppressing stickiness when applied to the skin, and more preferably a liquid at 25° C. among linear organopolysiloxanes and cyclic organopolysiloxanes. Yes, it is volatile.
Specific examples of the linear organopolysiloxane include octamethyltrisiloxane, decamethyltetrasiloxane, dodecamethylpentasiloxane, 1,1,1,3,5,5,5-heptamethyl-3-[(trimethylsilyl)oxy. ]-Trisiloxane is mentioned.
Examples of the cyclic organopolysiloxane include 4- to 6-membered cyclic siloxanes having an alkyl group having 1 to 5 carbon atoms as a substituent, and specific examples thereof include octamethylcyclotetrasiloxane and decamethylcyclopentasiloxane. Are listed.

Among the above, the component (B)' is preferably a cyclic organopolysiloxane, and more preferably decamethylcyclopentasiloxane, from the viewpoint of suppressing stickiness when applied to the skin.

Examples of commercially available volatile silicone oils that can be used as the component (B)' include "KF-96A-1cs" (octamethyltrisiloxane) and "KF-96L-1.5cs" manufactured by Shin-Etsu Chemical Co., Ltd. "(Decamethyltetrasiloxane), "KF-96L-2cs" (dodecamethylpentasiloxane), "KF-995" (decamethylcyclopentasiloxane), "TMF-1.5" (1, 1, 1, 3 , 5,5,5-Heptamethyl-3-[(trimethylsilyl)oxy]-trisiloxane), "SH200C Fluid 1cs" (octamethyltrisiloxane), manufactured by Toray Dow Corning Co., Ltd., "SH200C Fluid 1.5cs". (Decamethyltetrasiloxane), "SH200C Fluid 2cs" (dodecamethylpentasiloxane), "SH245 Fluid" (decamethylcyclopentasiloxane), "TSF405" (decamethylcyclopentasiloxane) manufactured by Momentive Performance Materials, Inc. Are listed.

When the external preparation for skin of the present invention contains the component (B)', its content is from the viewpoint of obtaining an excellent infrared protection effect and a real feeling of heat shielding, the natural appearance when applied to the skin, and the makeup after application. From the viewpoint of adhesiveness and stickiness suppressing effect, it is preferably 5% by mass or more, more preferably 10% by mass or more, further preferably 20% by mass or more, preferably 75% by mass or less, and more preferably It is 60% by mass or less, and more preferably 40% by mass or less. The specific range of the content of the component (B)' in the external preparation for skin is preferably 5% by mass or more and 75% by mass or less, more preferably 10% by mass or more and 60% by mass or less, and further preferably 20% by mass or more. It is from 40% by mass to 40% by mass.

(Surfactant (C))
The external preparation for skin of the present invention has an infrared protection effect and a viewpoint of achieving both the natural appearance when applied to the skin, and an oil component dispersed in water, or a water-soluble component dispersed in oil, Furthermore, it is preferable to contain a surfactant (C).
As the component (C), known surfactants such as anionic surfactants, cationic surfactants, amphoteric surfactants and nonionic surfactants can be used. Further, fluorine-based surfactants and silicone-based surfactants can also be used.
The external preparation for skin of the present invention, from the viewpoint of achieving both infrared protection effect and the natural appearance when applied to the skin, and from the viewpoint of dispersing an oily component in water or dispersing a water-soluble component in oil. It is preferable to contain at least a silicone-based surfactant, and it is more preferable to contain a nonionic silicone-based surfactant.

Examples of the silicone-based surfactant include polyether modified silicones represented by the following general formulas (1) to (3).

Wherein, ^{R 1} represents an alkyl group or a phenyl group having 1 to 5 carbon atoms, ^{R 2} is the formula _{- (CH 2) r -O- (} C 2 H 4 O) s - (C 3 H 6 O ) _T- R ⁵ (R ⁵ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, r is 1 to 5 numbers, s is 1 to 50 numbers, and t is 0 to 30 numbers). Represents a group represented, R ³ and R ⁴ represent the same group as any one of R ^{1 and} R ² , p represents a number of 5 or more and 300 or less, and q represents a number of 1 or more and 50 or less. However, not all of R ¹ are phenyl groups. ]

[In the formula, R ¹ , R ² , p and q are the same as defined above, R ⁶ represents an alkyl group having 2 or more and 20 or less carbon atoms, and R ⁷ and R ⁸ represent R ¹ , R ² or R ⁶ ; The same group as any one is shown, and u shows the number of 1 or more and 30 or less. However, not all of R ¹ are phenyl groups. ]

Wherein, ^{R 9} represents an alkyl group having 1 to 4 carbon ^{atoms, R 10} is the formula _{^{-Q 1 -O- (C 2 H 4}} O) x - (C 3 H 6 O) y R 14 (Q ¹ is a divalent hydrocarbon group having 1 to 4 carbon atoms, R ¹⁴ is a hydrogen atom, an alkyl group or acetyl group having 1 to 4 carbon atoms, x is 1 or more, y is 0 or more) R ¹¹ is a group represented by the formula: —Q ² —O—R ¹⁵ (Q ² is a divalent hydrocarbon group having 1 to 4 carbon atoms, and R ¹⁵ is a hydrocarbon group having 8 to 30 carbon atoms. ), R ¹² and R ¹³ are the same groups as any one of R ⁹ , R ¹⁰ or R ¹¹ , α is a number of 0 or more, and β and γ are numbers of 1 or more. Show. ]

The polyether-modified silicones represented by the above general formulas (1) to (3) have a branched chain in the silicone chain or are co-modified with a functional group other than the polyether within a range not departing from the purpose. It may have been done.

Examples of commercially available products of the polyether-modified silicone represented by the general formula (1) include "KF-6015" and "KF-6017" manufactured by Shin-Etsu Chemical Co., Ltd., manufactured by Toray Dow Corning Co., Ltd. "SH3775M" (polyoxyethylene/methylpolysiloxane copolymer), "SH3772C" and the like. Examples of the polyether-modified silicone represented by the above general formula (2) include those referred to as alkylpolyether-modified silicone, and examples of commercially available products include "Abil WE-09" manufactured by Gold Schmidt Co., Ltd., Shin-Etsu. "KF-6038" manufactured by Kagaku Kogyo Co., Ltd. and the like can be mentioned. Examples of the polyether-modified silicone represented by the above general formula (3) include polyoxyalkylene alkyl ether co-modified organopolysiloxane. For example, methyl hydrogen polysiloxane is co-modified with polyoxyalkylene allyl ether and allyl alkyl ether. It can be easily produced by modification.

Further, a partially cross-linked polyether modified silicone can be used as the silicone-based surfactant. Such a partially crosslinked polyether-modified silicone is obtained by addition-polymerizing an organohydrogenpolysiloxane and an aliphatic unsaturated group-containing compound, and is described in JP-A-4-272932 and JP-A-5-140320. What is done is illustrated.

The partially crosslinked polyether-modified organopolysiloxane polymer has the following general formula (4):
^{_{R 16 a R 17 b H c}} SiO (4-a-b-c) / 2 (4)
[In the formula, R ¹⁶ represents an alkyl group, an aryl group, an aralkyl group or a halogenated hydrocarbon group which may have a substituent having 1 to 18 carbon atoms, and R ¹⁷ represents a formula —C _n H _2n O ₂ (C ₂ H ₄ O) _d (C ₃ H ₆ O) _e R ¹⁸ (R ¹⁸ is a hydrogen atom, a saturated aliphatic hydrocarbon group having 1 to 10 carbon atoms or -C(O)-R ¹⁹ (R ¹⁹ Represents a monovalent group represented by a saturated aliphatic hydrocarbon group having 1 to 5 carbon atoms), d is a number of 2 or more and 200 or less, e is a number of 0 or more and 200 or less, d+e is 3 or more and 200 or less And n is 2 or more and 6 or less), a is 1≦a≦2.5, b is 0.001≦b≦1, and c is 0. 001≦c≦1 is shown. ]
Organohydrogenpolysiloxane represented by and/or the following general formula (5):
^{_{R 16 f H g SiO (4}} -f-g) / 2 (5)
[In the formula, R ¹⁶ is the same as above, f is 1≦f≦3, and g is 0.001≦g≦1.5. ]
An organohydrogenpolysiloxane represented by the following general formula (a):
_{C m H 2m-1 O (} C 2 H 4 O) h (C 3 H 6 O) i C m H 2m-1 (a)
[In the formula, h is a number of 2 or more and 200 or less, i is a number of 0 or more and 200 or less, h+i is a number of 3 or more and 200 or less, and m is a number of 2 or more and 6 or less. ]
And/or the following general formula (b):
^{_{R 16 j R 20 k SiO (}} 4-j-k) / 2 (b)
[In the formula, R ¹⁶ is the same as above, R ²⁰ represents a monovalent hydrocarbon group having an aliphatic unsaturated group at the end and having 2 to 10 carbon atoms, and j is 1≦j≦3, k Indicates 0.001≦k≦1.5, respectively. ]
In the combination with the organopolysiloxane represented by the formula (4), it is a polymer containing the component represented by the general formula (4) and/or the general formula (a) as an essential component.

As the surfactant other than the silicone-based surfactant, a nonionic surfactant is preferable, and a polyoxyethylene alkyl ether type nonionic surfactant is more preferable. Examples of commercially available nonionic surfactants include "Emulgen 121-G" (polyoxyethylene (21) lauryl ether) manufactured by Kao Corporation and "Emulgen 1620G" (polyoxyethylene (20) manufactured by Kao Corporation. ) 2-hexyldecyl ether), "Emulgen 2020G" (polyoxyethylene (20) octyldodecyl ether) manufactured by Kao Corporation, and the like.

The component (C) can be used alone or in combination of two or more. Among the above, as the component (C), one or more silicone-based surfactants selected from the group consisting of the polyether-modified silicones represented by the general formulas (1) to (3) are preferable, and the general formula ( A silicone-based surfactant which is a polyether-modified silicone represented by 1) is more preferable.

When the external preparation for skin of the present invention contains the component (C), its content is such that both the infrared protection effect and the natural appearance when applied to the skin are compatible, and the oily component is dispersed in water, Alternatively, from the viewpoint of dispersing the water-soluble component in oil, it is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, still more preferably 0.5% by mass or more, and It is preferably 15% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less, still more preferably 1.5% by mass or less. The specific range of the content of the component (C) in the external preparation for skin of the present invention is preferably 0.1% by mass or more and 15% by mass or less, more preferably 0.3% by mass or more and 10% by mass or less. It is more preferably 0.3% by mass or more and 5% by mass or less, and even more preferably 0.5% by mass or more and 1.5% by mass or less.

(Aqueous medium)
The external preparation for skin of the present invention may further contain an aqueous medium from the viewpoint of dispersing the component (A) and dispersing or dissolving other blending components to improve the coatability to the skin. The aqueous medium is not particularly limited as long as it can disperse or dissolve the component (A) and other compounding components, and examples thereof include water; monovalent C 4 or less carbon atoms such as ethanol, isopropyl alcohol, and butyl alcohol. Alcohol; low molecular weight diols and triols having 6 or less carbon atoms such as 1,3-butylene glycol, glycerin, ethylene glycol, propylene glycol, diethylene glycol and dipropylene glycol. Among these, at least one selected from the group consisting of water and monohydric alcohols having 4 or less carbon atoms is preferable, and one or more selected from the group consisting of water and ethanol is more preferable.

The content of the aqueous medium in the external preparation for skin can be appropriately selected depending on the dosage form of the external preparation for skin, but is preferably 1% by mass or more, more preferably 5% by mass or more, and further preferably 8%. Mass% or more, more preferably 10 mass% or more, preferably 98 mass% or less, more preferably 90 mass% or less, still more preferably 70 mass% or less, still more preferably 50 mass% or less. ..
The specific range of the content of the aqueous medium in the external preparation for skin is preferably 1% by mass or more and 98% by mass or less, more preferably 5% by mass or more and 98% by mass or less, and further preferably 8% by mass or more. It is 90 mass% or less, more preferably 10 mass% or more and 70 mass% or less, and even more preferably 10 mass% or more and 50 mass% or less.

<Other ingredients>
The external preparation for skin of the present invention contains, in addition to the above components, other components as necessary, for example, an ultraviolet absorber, an ultraviolet scattering agent, an emulsifier, an oil gelling agent, an antiperspirant, a fragrance, a moisturizer, and a thickener. , A bactericide, a pH adjuster, an antioxidant, a preservative and the like can also be contained.

(UV absorber)
The external preparation for skin of the present invention may further contain an ultraviolet absorber from the viewpoint of imparting an ultraviolet protective effect.
The UV absorber is preferably an organic UV absorber other than the components (B) and (B)', and an oil-soluble organic UV absorber or a water-soluble organic UV absorber can be used. From the viewpoint of UV protection effect, natural appearance when applied to the skin, good adhesiveness after application, and suppression of stickiness, the UV absorber is preferably an oil-soluble organic UV absorber. The term “oil-soluble” means that the solubility in water is 1 w/w% or less.
From the viewpoint of obtaining the effect of the present invention, it is preferable that the ultraviolet absorber does not include an inorganic ultraviolet absorber such as an ultraviolet absorber obtained by coating the surface of an inorganic filler with an ultraviolet absorbing material.

As the oil-soluble organic UV absorber, oil-soluble ones of salicylic acid-based UV absorbers, cinnamic acid-based UV absorbers, benzoylmethane-based UV absorbers, and other organic UV-absorbers can be used.
For example, salicylic acid-based UV absorbers such as homomenthyl salicylate and octyl salicylate;
2-Ethylhexyl paramethoxycinnamate (for example, "Ubinal MC80" manufactured by BASF), glyceryl mono-2-ethylhexanoate diparamethoxycinnamate, methyl 2,5-diisopropylcinnamate, methylbisbistrimethoxycinnamate (Trimethylsiloxy)silyl isopentyl, cinnamic acid-based UV absorbers such as paramethoxycinnamate/diisopropylcinnamate mixture;
A benzoylmethane-based ultraviolet absorber such as 4-isopropyldibenzoylmethane or 4-tert-butyl-4′-methoxydibenzoylmethane (for example, “Parasol 1789” manufactured by DSM Nutrition Japan);
Octocrylene (for example, "Parsol 340" manufactured by DSM Nutrition Japan), 2-ethylhexyl dimethoxybenzylidene dioxoimidazolidine propionate (for example, "Soft Shade DH" manufactured by Ajinomoto Co., Inc.), 1-(3,4-dimethoxyphenyl) )-4,4-Dimethyl-1,3-pentanedione, cinoxate, methyl-O-aminobenzoate, 3-(4-methylbenzylidene)camphor, octyltriazone, hexyl diethylaminohydroxybenzoylbenzoate (2-(4- Diethylamino-2-hydroxybenzoyl)benzoic acid hexyl ester, for example, "Ubinal Aplus" manufactured by BASF), bisethylhexyloxyphenol methoxyphenyltriazine (2,4-bis{[4-(2-ethylhexyloxy)-2-hydroxy] ] Phenyl}-6-(4-methoxyphenyl)-1,3,5-triazine, for example, "Tinosorb S" manufactured by BASF), methylenebisbenzotriazolyl tetramethylbutylphenol (for example, "Tinosorb M" manufactured by BASF) , 2,4,6-Tris[4-(2-ethylhexyloxycarbonyl)anilino]-1,3,5-triazine (hereinafter, also referred to as "ethylhexyltriazone", for example, "Ubinal T150" manufactured by BASF). And the like.

As the water-soluble organic UV absorber, salicylic acid-based UV absorbers, cinnamic acid-based UV absorbers, benzoylmethane-based UV absorbers, and other organic UV-absorbers have a solubility in water of 1 w/w%. Those exceeding the above range can be used, and examples thereof include triethanolamine salicylate and p-methoxyhydrocinnamic acid diethanolamine.

Among the above, as a UV absorber, 2-ethylhexyl paramethoxycinnamate, 4-tert-butyl-4′-methoxydibenzoylmethane, octocrylene, dimethoxybenzylidenedioxoimidazolidinepropionic acid 2 from the viewpoint of UV protection effect. -Ethylhexyl, hexyl diethylaminohydroxybenzoylbenzoate, bisethylhexyloxyphenol methoxyphenyltriazine, methylenebisbenzotriazolyltetramethylbutylphenol, and 2,4,6-tris[4-(2-ethylhexyloxycarbonyl)anilino] One or more selected from the group consisting of -1,3,5-triazine is preferable, and 2-ethylhexyl paramethoxycinnamate, hexyl diethylaminohydroxybenzoylbenzoate, bisethylhexyloxyphenol methoxyphenyltriazine, and 2,4,6 -Tris[4-(2-ethylhexyloxycarbonyl)anilino]-1,3,5-triazine is more preferably one or more selected from the group consisting of, and from the viewpoint of protecting both UVA and UVB, these are It is more preferable to combine two or more kinds. More preferably, it is at least one selected from the group consisting of 2-ethylhexyl paramethoxycinnamate, hexyl diethylaminohydroxybenzoylbenzoate, and bisethylhexyloxyphenol methoxyphenyltriazine, and it is more preferable to combine two or more thereof. More preferable.

When the external preparation for skin contains an ultraviolet absorbent, the content thereof is preferably 0.2% by mass or more, more preferably 1.5% by mass or more in the external preparation for skin from the viewpoint of the ultraviolet protection effect. %, more preferably 5% by mass or more, still more preferably 7% by mass or more. From the viewpoint of obtaining an excellent infrared protection effect and the viewpoint of makeup paste after application, it is preferably 30% by mass or less, more preferably 25% by mass or less, further preferably 20% by mass or less, More preferably, it is 15 mass% or less. The specific range of the content of the ultraviolet absorber in the external preparation for skin is preferably 0.2% by mass or more and 30% by mass or less from the viewpoint of achieving both the infrared protection effect, the makeup paste after application, and the ultraviolet protection effect. It is more preferably 1.5% by mass or more and 25% by mass or less, still more preferably 5% by mass or more and 20% by mass or less, and still more preferably 7% by mass or more and 15% by mass or less.

(Ultraviolet scattering agent)
The external preparation for skin of the present invention may further contain an ultraviolet scattering agent from the viewpoint of obtaining an ultraviolet protection effect.
As the ultraviolet scattering agent, inorganic particles are preferable, and metal oxide particles other than the component (A) are more preferable, because they have a high effect of scattering ultraviolet rays. Examples of the metal oxide include titanium oxide, zinc oxide, iron oxide, zirconium oxide, aluminum oxide and the like other than the component (A), which are selected from the group consisting of titanium oxide and zinc oxide other than the component (A) 1 More than one kind is more preferable.

From the viewpoint of dispersibility in the skin external preparation, the above-mentioned inorganic particles used for the ultraviolet scattering agent are preferably those which have been hydrophobized by surface treatment. Examples of the surface treatment method for hydrophobizing include silicone treatment with methylhydrogenpolysiloxane (hydrogendimethicone), methylpolysiloxane (dimethicone), methylhydrogenpolysiloxane/dimethylpolysiloxane copolymer, and the like; perfluoro Fluorine treatment with alkyl phosphate ester, perfluoroalcohol, etc.; Amino acid treatment with N-acyl glutamic acid, etc.; Hexyltrimethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane, octadecyltrimethoxysilane, octyltriethoxysilane, trifluoropropyl Silane compound treatment with trimethoxysilane, heptadecafluorodecyltrimethoxysilane, etc.; Silazane treatment with hexamethyldisilazane, octyldisilazane, etc.; Lecithin treatment; Metal soap treatment; Caprylic acid, pelargonic acid, capric acid, lauric acid, myristin Acid, palmitic acid, stearic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, araginic acid, arachidonic acid, behenic acid, etc. fatty acid treatment; alkyl phosphate ester treatment; silica, alumina, aluminum hydroxide etc. inorganic compound treatment; etc. Are listed. These surface treatment methods may be used alone or in combination of two or more.

The particle shape of the ultraviolet scattering agent may be spherical, rod-shaped, spindle-shaped, needle-shaped, plate-shaped, or irregular shape, but is not particularly limited as long as it has an ultraviolet-scattering effect.
The number average particle diameter of the ultraviolet scattering agent is usually 1 nm or more, and preferably 5 nm or more, more preferably 8 nm or more, and further preferably 10 nm or more from the viewpoint of obtaining an excellent ultraviolet protection effect. Further, from the viewpoint of the natural appearance when applied to the skin, it is preferably 500 nm or less, more preferably 300 nm or less, still more preferably 100 nm or less, still more preferably 60 nm or less.
The number average particle diameter is the transmission electron microscope (Transmission Electron Microscope: TEM), under the condition of 100,000 magnification, the maximum minor axis of the particle diameter of 300 particles in the image is measured, the average value It is obtained by calculating. Here, the maximum shortest diameter means the shortest diameter having the maximum diameter among the shortest diameters orthogonal to the longest diameter.

A commercial item can also be used for the ultraviolet scattering agent. Examples of commercially available titanium oxide particles other than the component (A) used as an ultraviolet scattering agent include "MT-100TV" (aluminum hydroxide, stearic acid treated) and "MTY-110M3S" manufactured by Teika Co., Ltd. ( Aluminum hydroxide, silica, hydrogen dimethicone treatment) and the like.

Examples of commercially available zinc oxide particles other than the component (A) used as the ultraviolet scattering agent include "FINEX-50-LPTM" (dimethicone treatment) and "FINEX-25" (surface) manufactured by Sakai Chemical Industry Co., Ltd. No treatment), "FINEX-25LP" (dimethicone treatment), "MZ-300" (no surface treatment) manufactured by Teika Co., Ltd., "MZ-504R3M" (hydrogen dimethicone treatment), "MZY-303S" (hydro) Gendimethicone treatment), "MZ-306X" (triethoxysilylethylpolydimethylsiloxyethylhexyldimethicone treatment), "MZ-200" (no surface treatment), "MZY-203S" (hydrogendimethicone treatment), "MZ-150" (No surface treatment), “MZY-153S” (hydrogendimethicone treatment), “MZ-505S”, “MZY-505S” and the like.

The ultraviolet scattering agents may be used alone or in combination of two or more.
When the external preparation for skin of the present invention contains an ultraviolet scattering agent, the content thereof is preferably 1% by mass or more, more preferably 3% by mass or more, and further preferably 5 from the viewpoint of the ultraviolet protection effect. It is at least mass%. Further, from the viewpoint of easy spread on the skin and smoothness when applied to the skin, the content is preferably 20% by mass or less, more preferably 18% by mass or less, and further preferably It is 15 mass% or less. The specific range of the content of the ultraviolet scattering agent in the external preparation for skin is preferably 1% by mass or more and 20% by mass or less, more preferably 3% by mass or more and 18% by mass or less, and further preferably 5% by mass. It is not less than 15% by mass.

(Method for producing external preparation for skin)
The method for producing the external preparation for skin of the present invention is not particularly limited, and a known method can be appropriately used depending on the dosage form of the external preparation for skin. For example, there may be mentioned a method in which the components (A) and (B) and all other components are mixed and uniformly mixed with a disperser or the like. Alternatively, a method may be used in which all components other than the aqueous medium are blended and uniformly mixed with a disperser or the like, and then the aqueous medium is blended and further stirred and mixed with a homogenizer or the like.
When the skin external preparation is a water-in-oil type emulsion composition or an oil-in-water type emulsion composition, a method of preparing an aqueous phase and an oil phase, respectively, and then mixing them can also be used.

[Infrared protection method for skin]
The present invention also provides an infrared protection method for skin, which comprises applying the external preparation for skin of the present invention to the skin. The infrared protection method of the present invention is not particularly limited as long as it has a step of applying the external preparation for skin of the present invention to the skin.

In the infrared protection method of the present invention, the infrared protection ratio at a wavelength of 1500 nm is preferably 10% or more, more preferably 12% or more, further preferably 15% or more. When the infrared ray protection rate at a wavelength of 1500 nm is 10% or more, the heat shielding feeling of the skin is good. The infrared protection rate (%) is a value represented by 100-X(%) when the infrared transmittance measured by a spectrophotometer is X(%), and specifically, the method described in Examples. Can be measured by

Regarding the above-described embodiment, the present invention further discloses the following embodiments.
<1>
It contains a plate-like metal oxide (A) having a thickness of 30 nm or more and 360 nm or less and an aspect ratio of 50 or more and 300 or less, and a non-volatile oil (B), and has a mass ratio [(A)/(B)] of 0. 0.05 or more and 5 or less, preferably 0.1 or more and 2 or less, more preferably 0.1 or more and 0.75 or less, still more preferably 0.2 or more and 0.5 or less, still more preferably Is 0.26 or more and 0.45 or less, more preferably 0.3 or more and 0.45 or less.
<2>
The thickness of the component (A) is preferably 50 nm or more, more preferably 60 nm or more, further preferably 80 nm or more, even more preferably 105 nm or more, even more preferably 125 nm or more, The external preparation for skin according to <1>, which is preferably 330 nm or less, more preferably 310 nm or less, still more preferably 280 nm or less, still more preferably 270 nm or less.
<3>
The aspect ratio of the component (A) is preferably 55 or more, and is preferably 230 or less, more preferably 200 or less, still more preferably 140 or less, still more preferably 125 or less, The skin external preparation according to <1> or <2>, further preferably 120 or less.
<4>
The metal oxide constituting the component (A) is preferably one or more selected from the group consisting of titanium oxide, zinc oxide, zirconium oxide, iron oxide, aluminum oxide and cerium oxide, and more preferably titanium oxide and The external preparation for skin according to any one of <1> to <3>, which is at least one selected from the group consisting of zinc oxide, and more preferably titanium oxide.
<5>
The content of the component (A) is preferably 1% by mass or more, more preferably 3% by mass or more, further preferably 6% by mass or more, still more preferably 8% by mass or more, and Any of <1> to <4>, preferably 35% by mass or less, more preferably 25% by mass or less, further preferably 17% by mass or less, still more preferably 12% by mass or less. The external preparation for skin according to item 1 or 2.
<6>
Component (B) is at least one selected from the group consisting of ester oils, silicone oils, hydrocarbon oils, higher fatty acids, and higher alcohols, and is preferably selected from the group consisting of ester oils, silicone oils and hydrocarbon oils. 1 or more, more preferably 1 or more selected from the group consisting of isopropyl palmitate, alkyl benzoate (C12 to C15), methyl polysiloxane, and light liquid isoparaffin, and further preferably containing methyl polysiloxane. The external preparation for skin according to any one of <1> to <5>.
<7>
The content of the component (B) is preferably 1% by mass or more, more preferably 5% by mass or more, further preferably 15% by mass or more, even more preferably 20% by mass or more, and even more It is preferably 25% by mass or more, preferably 45% by mass or less, more preferably 38% by mass or less, further preferably 35% by mass or less, still more preferably 32% by mass or less. The external preparation for skin according to any one of <1> to <6>.
<8>
It is a water-in-oil emulsion composition, and the content of the component (B) is preferably 10% by mass or more, more preferably 15% by mass or more, further preferably 18% by mass or more, and preferably Is 60 mass% or less, more preferably 40 mass% or less, and further preferably 30 mass% or less. The external preparation for skin according to any one of <1> to <6>.
<9>
It is an oil-in-water emulsion composition, and the content of the component (B) is preferably 30% by mass or less, more preferably 20% by mass or less, further preferably 10% by mass or less, and preferably The external preparation for skin according to any one of <1> to <6>, which is 1% by mass or more, more preferably 3% by mass or more, and further preferably 5% by mass or more.
<10>
The total content of the components (A) and (B) is preferably 2% by mass or more, more preferably 10% by mass or more, further preferably 20% by mass or more, still more preferably 30% by mass or more, still more preferably The external preparation for skin according to any one of <1> to <9>, which is 35% by mass or more and 100% by mass or less.

<11>
Further, it contains a volatile oil (B)', and the content thereof is preferably 5% by mass or more, more preferably 10% by mass or more, further preferably 20% by mass or more, and preferably 75% by mass or more. The external preparation for skin according to any one of <1> to <10>, which is not more than 60% by mass, more preferably not more than 60% by mass, further preferably not more than 40% by mass.
<12>
Component (B)' is one or more selected from the group consisting of volatile silicone oils, preferably linear organopolysiloxanes and cyclic organopolysiloxanes, more preferably cyclic organopolysiloxanes, even more preferably decamethylcyclopentasiloxane. The external preparation for skin according to <11>.
<13>
Further, it contains a surfactant (C), and its content is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, still more preferably 0.5% by mass or more. Further, it is preferably 15% by mass or less, more preferably 10% by mass or less, further preferably 5% by mass or less, still more preferably 1.5% by mass or less, <1> to < The external preparation for skin according to any one of 12>.
<14>
The external preparation for skin according to <13>, wherein the component (C) contains at least a silicone-based surfactant, and preferably a nonionic silicone-based surfactant.
<15>
It contains at least one plate metal oxide (A) selected from the group consisting of plate titanium oxide and plate zinc oxide having a thickness of 80 nm or more and 280 nm or less, and a non-volatile oil (B), and has a mass ratio [ (A)/(B)] is 0.2 or more and 5 or less, an external preparation for skin.
<16>
A component (B) containing at least one plate metal oxide (A) selected from the group consisting of plate titanium oxide and plate zinc oxide and having a thickness of 80 nm or more and 280 nm or less and a non-volatile oil (B). The external preparation for skin, wherein the content of () is 15% by mass or more and 38% by mass or less, and the mass ratio [(A)/(B)] is 0.2 or more and 0.5 or less.
<17>
The external preparation for skin according to any one of <1> to <16>, which is a skin cosmetic.
<18>
An infrared protection method for skin, which comprises applying the external preparation for skin according to any one of <1> to <17> to the skin.

Hereinafter, the present invention will be described by way of examples, but the present invention is not limited to the scope of the examples. In this example, various measurements and evaluations were performed by the following methods.

(Measurement of thickness, major axis, aspect ratio)
The thickness, major axis, and aspect ratio of the component (A) and inorganic particles other than the component (A) (indicated as “component (A)′” in the table) are determined by a scanning electron microscope (Keyence Corporation). "VE-9800" manufactured by Mitsui Chemicals Co., Ltd.) was used for observation under conditions of an acceleration voltage of 10 keV and an observation magnification of 10,000.
The thickness of the component (A) and the plate-shaped component (A)' was determined by measuring the thickness of 50 particles in the observed image and calculating the average value per number. The aspect ratio was obtained by measuring the thickness and major axis of 50 particles, calculating the aspect ratio (major axis/thickness) of each particle, and calculating the average value.

(Infrared protection rate)
28.5 mg of the skin external preparation of each example was applied to a 5 cm×5 cm polymethylmethacrylate resin (PMMA) substrate (“HD6” manufactured by HelioScreen), and dried for 15 minutes to prepare a sample for measurement. Similarly, glycerin was applied to a PMMA substrate and dried for 15 minutes, which was used as a control sample. For each of the measurement sample and the control sample, the transmittance at a wavelength of 1500 nm was measured in an integrating sphere mode with a spectrophotometer (“UV-3600” manufactured by Shimadzu Corporation). A value obtained by dividing the transmittance of the measurement sample by the transmittance of the control sample was taken as the transmittance X (%), and 100-X (%) was taken as the infrared protection rate. The larger this value, the higher the infrared protection effect.

(Natural appearance when applied to the skin)
About 0.1 g of the external preparation for skin of each example was applied to an area of about 2 cm×5 cm on the inside of the forearm, and one white point was felt when it was very white and very unnatural. The case where there was no discomfort was rated as 5 points and evaluated in 5 levels. Evaluation was carried out by 5 expert panelists, and the average score was used as the evaluation result.
<Evaluation criteria>
1: Very white and very unnatural 2: Somewhat white and unnatural 3: Neither 4: Natural white, but slightly uncomfortable 5: Natural white, no uncomfortable

(Paste after application)
About 0.1 g of the skin external preparation of each example was applied to an area of about 2 cm x 5 cm on the inner side of the forearm, and the “goodness of glue” of the foundation when the powder foundation was applied on it was found to be uneven and the foundation was very uneven. The case where the glue was poor was evaluated as 1 point, and the case where the foundation was uniform and the glue was very good was evaluated as 5 points and evaluated in 5 grades. Evaluation was carried out by 5 expert panelists, and the average score was used as the evaluation result.
<Evaluation criteria>
1: Foundation is non-uniform and very poorly glued 2: Foundation is slightly non-uniform and slightly poorly glued 3: Neither is 4: Foundation is slightly uniform and slightly glued 5: Foundation is evenly glued good

(Comprehensive evaluation)
In the evaluation results shown in Table 1, when the infrared protection rate is 10% or more, the natural appearance when applied to the skin is 3.5 or more, and the makeup paste after application is 3.5 or more, it passes ( In Table 1, it is shown as a failure (C evaluation) when there is even one evaluation item that does not satisfy the above criteria.

Production Example 1 (Production of plate-shaped titanium oxide 2)
A toluene solution in which 30% by mass of tetra-n-butyl orthotitanate was dissolved from the inner opening of the double-tube reactor (inner piping opening diameter 170 μm, outer piping opening diameter 400 μm) (hereinafter referred to as the first liquid). At a flow rate of 0.29 ml/min, and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide solution (hereinafter referred to as a second liquid) in which 1% by mass of water was dissolved from the outer opening. Was fed at a flow rate of 20.8 ml/min, and the two liquids were brought into contact with each other to cause a sol-gel reaction to obtain a plate-like titanium oxide gel. The temperature of the first and second liquids (reaction temperature) was 25° C., and the contact time (reaction time) of the first and second liquids at the liquid contact portion was 3 seconds. The obtained slurry was filtered through a metal mesh, and the gel of plate-shaped titanium oxide remaining on the metal mesh was washed with ethanol, dried and calcined to obtain solid plate-shaped titanium oxide 2. The plate-shaped titanium oxide 2 measured by the above method had a thickness of 264 nm and an aspect ratio of 57.

Production Example 2 (Production of comparative plate-shaped titanium oxide 1)
A plate-shaped titanium oxide 1 for comparison was obtained in the same manner as in Production Example 1 except that the flow rate of the first liquid was 0.14 ml/min and the flow rate of the second liquid was 10.4 ml/min. It was The thickness of the comparative plate-shaped titanium oxide 1 measured by the above method was 388 nm, and the aspect ratio was 39.

Examples 1 to 11 and Comparative Examples 1 to 5 (production and evaluation of skin external preparation)
Of the components shown in Table 1, all components except water and ethanol were mixed and uniformly mixed with a disper. Next, water and ethanol were added to the obtained mixed liquid and mixed uniformly using a homogenizer to produce a water-in-oil type external preparation for skin having the composition shown in Table 1. The obtained external preparation for skin was evaluated by the above method. The results are shown in Table 1. The blending amounts shown in Table 1 are the active ingredient amounts (mass %) of each component.

The compounding ingredients in Table 1 are as follows.
*1: 7.5% by mass of (alkyl acrylate/dimethicone) copolymer of "Featheleve PT-7801K" manufactured by CQV, treated with coating *2: the plate-shaped titanium oxide 2 (alkyl acrylate/ Dimethicone) Copolymer 7.5% by mass coating-treated product *3: CQV “Featheleve PT-9001K” (alkyl acrylate/dimethicone) copolymer 7.5% by mass coating-treated product *4: Obtained in Production Example 2 (Alkyl acrylate/dimethicone) copolymer 7.5% by mass coated with comparative plate-shaped titanium oxide *5: "Flamenco Satin Blue" (titanium oxide coating layer thickness: 10 nm) manufactured by BASF Alkyl/dimethicone) Copolymer 7.5% by mass coating treatment product *6: "Silicone KF-96A-10cs" manufactured by Shin-Etsu Chemical Co., Ltd.
*7: "Finsolve TN" manufactured by Innospec Active Chemicals
*8: "Exepar IPP" manufactured by Kao Corporation
*9: “Purple Ream 4” manufactured by NOF Corporation, light liquid isoparaffin (hydrogenated polyisobutene)
*10: "TSF405" manufactured by Momentive Performance Materials, Inc.
*11: "SH3775M" manufactured by Toray Dow Corning Co., Ltd., polyoxyethylene-methylpolysiloxane copolymer (PEG-12 dimethicone)

From Table 1, the external preparations for skin of Examples 1 to 11 have good infrared protection effect, natural appearance when applied to the skin, and good cosmetic paste after application. For example, from the comparison between Examples 1 to 3 and Comparative Example 1, when the plate-shaped titanium oxide having a predetermined thickness range specified in the present invention is used, the infrared protection effect is improved, and when applied to the skin. It can be seen that the naturalness of the appearance and the makeup after application are improved. In particular, when the component (A) having a thickness in the range of 80 nm or more and 280 nm or less is used, the infrared protection effect is further improved.
On the other hand, the external preparation for skin of Comparative Example 1 using the plate-like titanium oxide having a thickness of more than 360 nm in place of the component (A) has a low infrared protection effect, and has a natural appearance when applied to the skin, and application. The makeup glue afterwards also got worse. Even in Comparative Example 2 in which plate-like inorganic particles other than the metal oxide were used instead of the component (A), the excellent infrared protection effect was not obtained.
In Comparative Example 3 containing no component (B), the natural appearance when applied to the skin and the makeup paste after application were deteriorated.
Further, Comparative Example 4 in which the mass ratio [(A)/(B)] of the component (A) and the component (B) in the external preparation for skin is less than 0.05, mass ratio [(A)/(B)]. In Comparative Example 5 in which the ratio was 5 or more, the naturalness of appearance when applied to the skin and the makeup paste after application could not be improved, and in Comparative Example 4, the infrared protection effect was also low.

Prescription example 1 (Production of external preparation for skin)
Of the components shown below, all the components except water and ethanol were mixed and uniformly mixed with a disper. Next, water and ethanol were added to the obtained mixed liquid and mixed uniformly using a homogenizer to produce a water-in-oil type emulsion composition (external preparation for skin) having the following composition.
(mass%)
(A) Plate-shaped titanium oxide 1
(CQV "Featheleve PT-7801K" octyltriethoxysilane 2% by mass coating treated product, thickness 134 nm/aspect ratio 112) 15.0
(B) Methyl polysiloxane (Shin-Etsu Chemical Co., Ltd. "Silicone KF-96A-10cs") 6.0
(B) Liquid isoparaffin (“Pearl Ex” manufactured by NOF CORPORATION) 15.0
(B)' Decamethylcyclopentasiloxane ("TSF405" manufactured by Momentive Performance Materials, Inc.)
10.0
(C) Polyoxyethylene/methylpolysiloxane copolymer (“Silicone SH3775M” manufactured by Toray Dow Corning Co., Ltd.) 1.0
N-propionyl polyethyleneimine/methylpolysiloxane copolymer ("Polysilicone-9" manufactured by Kao Corporation) 0.2
Ultraviolet absorber (2-ethylhexyl paramethoxycinnamate, "Ubinal MC80" manufactured by BASF)
10.0
(Bisethylhexyloxyphenol methoxyphenyl triazine, "Tinosorb S" manufactured by BASF) 2.0
Titanium oxide (Taika Corporation "JR-1000") 5.0
Ethanol 10.0
Glycerin 1.0
Water balance
Total 100.0
(Mass ratio (A)/(B)=0.71)

Prescription example 2 (Production of external preparation for skin)
Water, 1,3-butylene glycol, and ethanol among the components shown below were put in a blending tank and stirred to prepare an aqueous phase. On the other hand, at a temperature of about 80° C., the remaining components were added and mixed to prepare an oil phase. The oil phase was added to the obtained aqueous phase, uniformly mixed using a homogenizer, and cooled to produce an oil-in-water emulsion composition (skin external preparation) having the following composition.
(mass%)
(A) Plate-shaped titanium oxide 1
(2% by mass coating of octyltriethoxysilane of "Featheleve PT-7801K" manufactured by CQV, thickness 134 nm/aspect ratio 112) 8.0
(B) Neopentyl glycol dicaprate (“Estemol N-01” manufactured by Nisshin Oillio Co., Ltd.) 5.0
(B)' Decamethylcyclopentasiloxane ("TSF405" manufactured by Momentive Performance Materials, Inc.) 3.0
(C) Polyoxyethylene sorbitan monostearate ("Leodol TW-S120V" manufactured by Kao Corporation) 0.6
(C) Sorbitan stearate ("Leodoll SP-S10V" manufactured by Kao Corporation) 0.6
Emulsifier ((Na acrylate/acryloyl dimethyl taurine Na) copolymer dispersion, "SIMULGEL EG" manufactured by Sepic Co.) 1.5
Ultraviolet absorber (2-ethylhexyl paramethoxycinnamate, "Ubinal MC80" manufactured by BASF)
10.0
(Bisethylhexyloxyphenol methoxyphenyl triazine, "Tinosorb S" manufactured by BASF) 1.0
Ultraviolet scattering agent (aluminum hydroxide/stearic acid coated fine particle titanium oxide, "MT-100TV" manufactured by Teika Co., Ltd.) 3.0
Ethanol 10.0
1,3-butylene glycol 1.0
Water balance
Total 100.0
(Mass ratio (A)/(B)=1.6)

Prescription example 3 (Production of external preparation for skin)
Water, (Acrylates/alkyl acrylate (C10-30)) crosspolymer, 1,3-butylene glycol, and ethanol among the components shown below were put in a mixing tank and stirred to prepare an aqueous phase. On the other hand, at a temperature of about 80° C., the remaining components other than potassium hydroxide among the components shown below were added and mixed to prepare an oil phase. After adding the oil phase to the obtained aqueous phase and stirring, potassium hydroxide was added, and the mixture was uniformly mixed using a homogenizer and cooled, and the oil-in-water emulsion composition having the following composition (skin external preparation ) Was manufactured.
(mass%)
(A) Plate-shaped titanium oxide 1
(CQV "Featheleve PT-7801K" octyltriethoxysilane 2% by mass coating treated product, thickness 134 nm/aspect ratio 112) 10.0
(B) Isopropyl palmitate ("Exepar IPP" manufactured by Kao Corporation) 3.0
(B) Methyl polysiloxane (Shin-Etsu Chemical Co., Ltd. "Silicone KF-96A-10cs") 1.0
(C) Polyoxyethylene sorbitan monostearate ("Leodoll TW-S120V" manufactured by Kao Corporation) 0.1
Thickener (Acrylates/alkyl acrylate (C10-30)) crosspolymer, Lubrizol "PEMULEN TR-1" 0.4
Oil gelling agent (dextrin palmitate, "Leopearl KL2" manufactured by Chiba Milling Co., Ltd.) 1.0
Ultraviolet absorber (2-ethylhexyl paramethoxycinnamate, "Ubinal MC80" manufactured by BASF)
8.0
(Bisethylhexyloxyphenol methoxyphenyl triazine, "Tinosorb S" manufactured by BASF) 2.0
UV Scattering Agent (Aluminum Hydroxide/Stearic Acid Coated Fine Particle Titanium Oxide, "MT-100TV" manufactured by Teika Co., Ltd.) 5.0
Ethanol 5.0
1,3-butylene glycol 3.0
Potassium hydroxide 0.25
Water balance
Total 100.0
(Mass ratio (A)/(B)=2.5)

The external preparation for skin of the present invention has an excellent infrared protection effect, has a natural appearance when applied to the skin and has a natural appearance after application, and has a good feel after application. It is useful.

Claims (8)

It contains a plate-like metal oxide (A) having a thickness of 30 nm or more and 360 nm or less and an aspect ratio of 50 or more and 300 or less, and a non-volatile oil (B), and has a mass ratio [(A)/(B)] of 0. An external preparation for skin of 0.05 or more and 5 or less. The external preparation for skin according to claim 1, wherein the content of the plate-shaped metal oxide (A) is 1% by mass or more and 35% by mass or less. The external preparation for skin according to claim 1 or 2, wherein the plate-shaped metal oxide (A) is at least one selected from the group consisting of plate-shaped titanium oxide and plate-shaped zinc oxide. The external use of the skin according to any one of claims 1 to 3, wherein the nonvolatile oil (B) is one or more selected from the group consisting of ester oil, silicone oil, hydrocarbon oil, higher fatty acid, and higher alcohol. Agent. The external preparation for skin according to any one of claims 1 to 4, which is a water-in-oil emulsion composition and has a content of the nonvolatile oil (B) of 10% by mass or more. The external preparation for skin according to any one of claims 1 to 4, which is an oil-in-water emulsion composition, and the content of the nonvolatile oil (B) is 30% by mass or less. The external preparation for skin according to any one of claims 1 to 6, which is a skin cosmetic. An infrared protection method for skin, which comprises applying the external skin preparation according to any one of claims 1 to 7 to the skin.