Ultraviolet light scattering agent

Abstract

To provide an ultraviolet scattering agent excellent in safety and capable of shielding (blocking) ultraviolet rays while transmitting visible rays.SOLUTION: The ultraviolet light scattering agent is obtained by dispersing clay minerals having a particle size of 350nm or less in a liquid medium.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an ultraviolet scattering agent. [Background technology]

[0002] Sunscreen cosmetics (sunscreens) containing UV protection agents (UV absorbers, UV scattering agents) have been developed and are widely available on the market to protect skin from UV exposure and inhibit melanin production and photoaging, which causes spots and wrinkles. UV-B, in particular, is extremely harmful to the skin, and exposure to UV-B can cause inflammation (sunburn) and melanin pigmentation (suntan). For this reason, in recent years, efforts have been made to develop sunscreens that can protect skin from UV-B in particular. Sunscreens are often used daily to protect skin from UV rays, and safer options are in demand. Among the UV protection agents mentioned above, UV absorbers react chemically with UV rays to convert them into heat energy, which is then released to protect the skin from UV rays. However, this chemical reaction can cause skin irritation, redness, and eczema, leading to a growing demand for so-called non-chemical sunscreens that are free of UV absorbers. These sunscreens contain UV scattering agents, such as zinc oxide and titanium oxide, which physically scatter and reflect UV rays to protect the skin from UV rays.

[0003] While UV scattering agents such as zinc oxide and titanium oxide have been reported to have UV-blocking effects, they are also known to have poor spreadability and poor application comfort. To address these issues, Patent Document 1, for example, discloses a sunscreen formulation that incorporates UV scattering agents such as zinc oxide and titanium oxide while maintaining a light feel. It describes a sunscreen formulation comprising an oil-in-water emulsion composition containing, as essential ingredients, 1 to 20% by weight of a metal oxide UV scattering agent (A), a hydrophilic thickener containing a clay mineral hydrophilic thickener (B) and xanthan gum (C), an oily component (D), a surfactant containing a nonionic surfactant (E) and an anionic surfactant (F), and an aqueous component (G) containing 40% or more by weight of water. It also describes that the metal oxide UV scattering agents such as titanium oxide and zinc oxide can protect the skin from UV rays, and that the combined use of the hydrophilic thickeners clay mineral and xanthan gum can result in a sunscreen formulation with excellent stability over time and a light feel. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-113416 Summary of the Invention [Problem to be solved by the invention]

[0005] As mentioned above, sunscreens are used daily, and therefore are required to be not only comfortable to wear but also aesthetically pleasing. UV scattering agents such as zinc oxide and titanium oxide, which are commonly used as UV protection agents with few skin problems, reflect not only UV rays but also visible light, so they are white in themselves and tend to cause a white cast when applied to the skin. This white cast is particularly noticeable when a large amount of sunscreen is applied to the skin to protect it from UV rays, so there are limitations on the amount of sunscreen that can be applied at one time from the perspective of aesthetics.

[0006] An object of the present invention is to provide an ultraviolet scattering agent that is excellent in safety and can block ultraviolet rays while transmitting visible light. [Means for solving the problem]

[0007] As a result of extensive research in light of the above-mentioned problems, the present inventors have found that by incorporating smectite, which has a proven track record of use as a thickener and emulsifier in the field of cosmetics and is highly safe for the human body, and controlling the particle size to a specific value or less, an aqueous dispersion containing this can exhibit a high blocking effect against UV rays while still allowing sufficient transmission of visible light, i.e., it can protect the skin from UV rays without leaving a white cast when applied to the skin. The present invention was completed based on these findings.

[0008] That is, the above-mentioned problems of the present invention have been solved by the following means. [1] An ultraviolet scattering agent consisting of clay minerals with particle diameters of 350 nm or less dispersed in a liquid medium. [2] The ultraviolet scattering agent according to [1] above, wherein the content of the clay mineral is 0.1 to 10 mass %. [3] The ultraviolet scattering agent according to [1] or [2] above, which has a light transmittance of 30% or more for visible light with a wavelength of 500 nm and a light transmittance of 40% or less for ultraviolet light with a wavelength of 280 nm, and which has a lower light transmittance for ultraviolet light with a wavelength of 280 nm than the light transmittance for visible light with a wavelength of 500 nm. [4] The ultraviolet scattering agent according to any one of [1] to [3] above, wherein the clay mineral is selected from saponite, hectorite, and stevensite. [5] The ultraviolet scattering agent according to any one of [1] to [4] above, wherein the main interlayer cations of the clay mineral are sodium ions. [6] The ultraviolet scattering agent according to any one of [1] to [5] above, for use in cosmetics. [7] A cosmetic preparation comprising the ultraviolet scattering agent according to any one of [1] to [6] above. [Effects of the Invention]

[0009] The ultraviolet scattering agent of the present invention is excellent in safety and can effectively block ultraviolet rays while sufficiently transmitting visible light. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a graph showing the transmittance of visible light and ultraviolet light through the ultraviolet scattering agents of the examples. DETAILED DESCRIPTION OF THE INVENTION

[0011] Preferred embodiments of the present invention will be specifically described below, but the present invention is not limited to these embodiments except as defined in the present invention.

[0012] [UV scattering agent] The ultraviolet scattering agent of the present invention is a dispersion in which clay minerals with particle diameters of 350 nm or less are dispersed in a liquid medium, and is an agent for blocking (blocking) ultraviolet rays. Due to its light-scattering properties, the ultraviolet scattering agent of the present invention can effectively block ultraviolet rays while sufficiently transmitting visible light. That is, the light transmittance (hereinafter also simply referred to as "transmittance") of ultraviolet rays passing through the ultraviolet scattering agent of the present invention is lower than the transmittance of visible light. In the present invention and this specification, "visible light" refers to electromagnetic waves (radiation) with a wavelength of 400 nm or more and 770 nm or less. Furthermore, "ultraviolet rays" refers to electromagnetic waves (radiation) with a wavelength of less than 400 nm. Furthermore, ultraviolet rays are classified by wavelength into UV-A (wavelength of 315 nm or more and less than 400 nm), UV-B (wavelength of 280 nm or more and less than 315 nm), and UV-C (wavelength of 100 nm or more and less than 280 nm). The ultraviolet rays blocked by the ultraviolet scattering agent of the present invention preferably include UV-B. In the ultraviolet scattering agent of the present invention, the particle diameter of the clay mineral, which is the dispersoid, is controlled to 350 nm or less and is stably dispersed in the dispersion medium. In such a dispersion system, Rayleigh scattering occurs, in which the shorter the wavelength of light, the more strongly it is scattered. Therefore, visible light having a relatively long wavelength is transmitted without scattering, maintaining transparency, and light having a relatively short wavelength, such as ultraviolet light, can be effectively scattered. Therefore, in the ultraviolet scattering agent of the present invention, visible light can be transmitted through the ultraviolet scattering agent with high efficiency (high transmittance), and ultraviolet light is scattered by the ultraviolet scattering agent (low transmittance) and is blocked.

[0013] <Visible light transmittance, UV transmittance> The ultraviolet scattering agent of the present invention can effectively scatter and shield ultraviolet rays (reduce the transmittance) while sufficiently transmitting visible light due to the light scattering properties of the clay mineral that is the dispersoid. Due to such light scattering properties, for example, when the ultraviolet scattering agent of the present invention is used in a cosmetic and applied to the skin, it does not cause a white cast and can protect the skin from ultraviolet rays. For example, the ultraviolet scattering agent of the present invention preferably has a transmittance of 30% or more, more preferably 50% or more, and even more preferably 70% or more for visible light with a wavelength of 500 nm. Furthermore, the transmittance of 280 nm ultraviolet light is preferably 70% or less, more preferably 40% or less, and even more preferably 20% or less. Furthermore, the transmittance of 250 nm ultraviolet light is preferably 40% or less, more preferably 20% or less, and even more preferably 10% or less. Furthermore, the transmittance of 280 nm ultraviolet light is preferably lower than the transmittance of 500 nm visible light, and it is more preferable that the transmittance of 500 nm visible light, the transmittance of 280 nm ultraviolet light, and the transmittance of 250 nm ultraviolet light are lower in this order. The transmittance can be calculated using an optical path length of 10 mm and the ratio φt / φi of the radiant flux or luminous flux φt of transmitted light to the radiant flux or luminous flux φi of incident light. The transmittance can also be measured using an ultraviolet-visible spectrophotometer (UV-1800, manufactured by Shimadzu Corporation) as described in the Examples, for example. Furthermore, since the UV scattering agent of the present invention is a dispersion liquid in which clay minerals are dispersed, it has excellent water retention properties and can suppress water evaporation. Furthermore, for example, when the UV scattering agent of the present invention itself or a cosmetic preparation containing the UV scattering agent is applied to the skin, even if the liquid medium evaporates to a certain extent, aggregation of the clay minerals is suppressed and dispersibility is maintained, so that the agent can exhibit the effect of effectively scattering and blocking UV rays while sufficiently transmitting visible light.

[0014] The characteristic features of the ultraviolet scattering agent of the present invention will be described below.

[0015] (clay minerals) In the UV scattering agent of the present invention, the clay mineral, which is an active ingredient, constitutes a dispersoid. The type of clay mineral is not particularly limited and can be appropriately selected depending on the purpose. Clay minerals themselves are known and commercially available. The clay mineral is preferably smectite. Examples of the smectite include montmorillonite, beidellite, nontronite, saponite, hectorite, fluorohectorite, sauconite, and stevensite. One or more of these smectites are preferred, and one or more selected from saponite, hectorite, fluorohectorite, and stevensite are more preferred, with hectorite being even more preferred. The smectite may be natural or synthetic, and is preferably synthetic from the viewpoint of low impurity content. The synthetic smectite may be smectite having hydroxyl groups at the crystal terminals, or may be fluorinated smectite in which the hydroxyl groups are substituted with fluorine atoms. Synthetic smectite can be produced by a conventional method.

[0016] The main interlayer cations of the smectite are preferably sodium ions or lithium ions. In the present invention and this specification, the term "main interlayer cations" refers to cations whose molar fraction is 50% or more of the total molar amount of interlayer cations of the smectite. For example, when the main interlayer cations of the smectite are sodium ions (i.e., the smectite is a sodium-type smectite), the proportion of sodium ions in the total interlayer cations of the smectite is 50% or more on a molar basis. The proportion of sodium ions or lithium ions in the total interlayer cations (total molar amount) of the smectite is preferably 80% or more, more preferably 90% or more. Furthermore, the proportion of sodium ions in the total interlayer cations (total molar amount) of the smectite is preferably 80% or more, more preferably 90% or more. By using sodium ions as the main interlayer cations, for example, superior swelling properties and superior dispersion stability can be imparted when the clay mineral is dispersed in an aqueous medium or the like. The cation exchange capacity (CEC) of the smectite is preferably 15 meq (milliequivalent) / 100 g or more, more preferably 20 meq / 100 g or more, and even more preferably 25 meq / 100 g or more, from the viewpoint of improving swelling properties during dispersion. The cation exchange capacity of the smectite usable in the present invention is usually 250 meq / 100 g or less.

[0017] When dispersed in an aqueous medium such as water, the clay mineral exfoliates, disperses, swells, and becomes fine particles that are stably dispersed. In the ultraviolet scattering agent of the present invention, the particle diameter of the clay mineral is 350 nm or less. From the viewpoint of more effectively blocking ultraviolet rays, the particle diameter is preferably 10 nm or more, more preferably 20 nm or more, and even more preferably 30 nm or more. Furthermore, from the viewpoint of further improving the transparency of the ultraviolet scattering agent of the present invention, the particle diameter is preferably 200 nm or less, more preferably 170 nm or less, and even more preferably 140 nm or less. Furthermore, by controlling the particle diameter of the clay mineral to be within the above-mentioned preferred range, a more stable dispersed state can be maintained in the system. In the present invention, the "particle size" of the clay mineral in the dispersion liquid refers to the volume-based median size, which can be determined, for example, by a laser diffraction / scattering particle size distribution analyzer.

[0018] In the UV scattering agent of the present invention, the content of the clay mineral is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more. Furthermore, the content is preferably 10% by mass or less, more preferably 7% by mass or less, and even more preferably 5% by mass or less. The preferred range of the content is preferably 0.1 to 10% by mass, more preferably 0.5 to 7% by mass, and even more preferably 1 to 5% by mass.

[0019] The clay mineral can also function as a radical scavenger in the UV scattering agent of the present invention. Because clay minerals exhibit a reducing action in a dispersed state, it is believed that the clay mineral also functions as a source of electrons, thereby capturing radicals. In particular, it is known that UV scattering agents such as titanium oxide, which are commonly incorporated into cosmetics, generate radicals when irradiated with UV rays. By incorporating the UV scattering agent of the present invention, it is possible to capture such radicals generated by UV irradiation, which can lead to improvements in the quality and functionality of cosmetics such as sunscreens.

[0020] (Other UV protection agents) From the viewpoint of improving the ultraviolet shielding effect, the ultraviolet scattering agent of the present invention may contain other ultraviolet protection agents (ultraviolet absorbers, ultraviolet scattering agents) within the scope that does not impair the effects of the present invention. Examples of such ultraviolet protection agents include inorganic ultraviolet scattering agents made of inorganic powders and organic ultraviolet absorbers made of phenolic substances having conjugated double bonds. The content of the other ultraviolet protection agents in the ultraviolet scattering agent of the present invention is preferably 0.01 to 10% by mass per other ultraviolet protection agent. Furthermore, when the ultraviolet scattering agent of the present invention contains multiple types of other ultraviolet protection agents, the content is preferably 0.03 to 30% by mass of the total other ultraviolet protection agents.

[0021] (Other ingredients) The UV scattering agent of the present invention may also contain other components such as additives, provided that the effects of the present invention are not impaired. Examples of such additives include pH adjusters, moisturizers, antioxidants, fragrances, various vitamins, chelating agents, colorants, medicinal ingredients, inorganic salts, preservatives, and plant extracts, all of which are useful in skin care products. Furthermore, stabilizers, antifoaming agents, specific gravity adjusters, viscosity adjusters, organic solvents, surfactants, emollients, pigments, and the like may also be used in combination. These additives may be used singly or in combination of two or more. The content of each additive in the UV scattering agent of the present invention is preferably 0.01 to 10% by mass per additive. When the UV scattering agent of the present invention contains multiple types of the above-mentioned other components, the total content of the other components is preferably 0.05 to 50% by mass.

[0022] (liquid medium) The ultraviolet scattering agent of the present invention is a dispersion in which a clay mineral is dispersed in a liquid medium. Such a liquid medium is not particularly limited, and various liquid media capable of dispersing a clay mineral can be used. Among them, from the viewpoint of the dispersion stability of the clay mineral, the liquid medium is preferably an aqueous medium such as water or an aqueous solution, and more preferably water. Note that the liquid medium may also be a liquid medium containing the above-mentioned other components. Furthermore, from the viewpoint of improving the dispersion stability of the clay mineral, the liquid medium may also be a liquid medium to which a thickener such as glycerin has been previously blended. The water is not particularly limited and may be tap water or purified water such as distilled water or ion-exchanged water. From the viewpoint of dispersion stability, purified water from which ions have been removed is particularly preferred. In this case, the ionic conductivity of the water is preferably 10 μS / m or less, more preferably 5 μS / m or less, and even more preferably 2 μS / m or less.

[0023] <ph> The pH of the UV scattering agent of the present invention is not particularly limited, but from the viewpoints of safety for the human body and ease of handling, such as disposal, it is preferably a weakly acidic to weakly alkaline pH of 3.0 to 11.0 at room temperature (25°C). For example, when smectite in which the interlayer cations are sodium ions or lithium ions is dispersed as is in water, the pH is often in the weakly alkaline range of about 8 to 11. When such smectite is used as the clay mineral, the resulting dispersion can be used as the UV scattering agent of the present invention as is without adjusting the pH. Furthermore, since the pH of human skin is generally considered to be weakly acidic, ranging from 4.5 to 6.5, a pH adjuster can be added to the UV scattering agent of the present invention to adjust the pH to within this weakly acidic range. The acidic compound used as the pH adjuster may be, for example, an organic acid, which is an acidic organic compound having a carboxyl group or a phosphate group, or an inorganic acid (mineral acid), such as hydrochloric acid, sulfuric acid, or nitric acid. It may also be an acidic compound with reducing power (acidic reducing agent). The pH adjuster may be incorporated into the cosmetics described below.

[0024] <Viscosity> The ultraviolet scattering agent of the present invention has an appropriate viscosity due to the clay mineral contained therein being dispersed in the form of fine particles, and therefore, for example, even if the ultraviolet scattering agent of the present invention does not contain a thickener (thickening polysaccharide) such as methylcellulose or xanthan gum, it can have excellent adhesion to the skin, etc. The ultraviolet scattering agent of the present invention preferably has a viscosity of 10 mPa·s or more, more preferably 100 mPa·s or more, even more preferably 500 mPa·s or more, and even more preferably 1000 mPa·s or more, at 25°C. From the viewpoint of ease of handling as a liquid, the viscosity is preferably 200,000 mPa·s or less, more preferably 100,000 mPa·s or less, even more preferably 10,000 mPa·s or less, and even more preferably 5,000 mPa·s or less. The viscosity can be measured, for example, using a Brookfield (B-type) viscometer at a measurement temperature of 25°C with a rotor appropriate for the viscosity range, rotated at 12 rpm, 60 seconds after the start of rotation.

[0025] [Cosmetics] Another preferred embodiment of the present invention is a cosmetic containing (blended with) the UV scattering agent of the present invention. Forms of cosmetic containing the UV scattering agent of the present invention also include those in which the cosmetic is the UV scattering agent of the present invention itself (i.e., those in which the cosmetic does not contain any components other than the UV scattering agent of the present invention). The amount of the UV scattering agent of the present invention blended in the cosmetic of the present invention is not particularly limited, and can be appropriately set so that the content of the clay mineral contained in the cosmetic of the present invention is within the preferred range described below. The cosmetic preparation of the present invention includes, for example, various cosmetics or cosmetic preparations such as base makeup (primer) cosmetics, makeup (finishing) cosmetics, skin cosmetics, and body powder. Of these, the cosmetic preparation is preferably a sunscreen. Examples of such sunscreens include gel-type, cream-type, spray-type, and powder-type sunscreens, with gel-type sunscreens being preferred.

[0026] The content of the clay mineral in the cosmetic is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more. Furthermore, the content is preferably 10% by mass or less, more preferably 7% by mass or less, and even more preferably 5% by mass or less. The preferred range of the content is preferably 0.1 to 10% by mass, more preferably 0.5 to 7% by mass, and even more preferably 1 to 5% by mass. The cosmetic may also contain other ultraviolet protection agents and other ingredients as described above in connection with the ultraviolet scattering agent of the present invention.

[0027] Furthermore, since the UV scattering agent of the present invention contains a clay mineral, it also functions as a surfactant, and therefore can be blended in the above-mentioned cosmetic preparation in place of other surfactants, or the amount of other surfactants blended can be reduced. [Example]

[0028] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples.

[0029] <Example of test solution preparation> The materials used to prepare each test solution are as follows: The main interlayer cation of the clay minerals listed below is sodium ion. (clay minerals) Sumecton-SA (trade name): Synthetic clay, saponite, cation exchange capacity 66 meq / 100 g, primary particle size 90 nm, manufactured by Kunimine Industries Co., Ltd. Sumecton-SWN (trade name): Synthetic clay, hectorite, cation exchange capacity 43 meq / 100 g, primary particle size 70 nm, manufactured by Kunimine Industries Co., Ltd. Sumecton-ST (trade name): Synthetic clay, Stevensite, cation exchange capacity 25 meq / 100 g, primary particle size 40 nm, manufactured by Kunimine Industries Co., Ltd. Laponite-XLG (trade name): Synthetic clay, hectorite, cation exchange capacity 20 meq / 100 g, primary particle size 35 nm, manufactured by BYK Laponite-B (trade name): Synthetic clay, hectorite, cation exchange capacity 70 meq / 100 g, primary particle size 130 nm, manufactured by BYK Kunipia-F (product name): Natural clay, montmorillonite, cation exchange capacity 110 meq / 100 g, primary particle size 400 nm, manufactured by Kunimine Industries Co., Ltd. (Other UV scattering agents) Zinc oxide: Primary particle diameter 80 nm, manufactured by Titan Kogyo Co., Ltd. (dispersion medium) Glycerin: Reagent grade, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. CY-5 (trade name): Decamethylcyclopentasiloxane, manufactured by Shin-Etsu Chemical Co., Ltd.

[0030] (Examples 1, 3 to 7, Comparative Example 1) The clay minerals shown in Table 1 below were dispersed in distilled water (electrical conductivity 0.2 μS / cm or less) at the blending ratios shown in Table 1 to prepare ultraviolet scattering agents.

[0031] Example 2 The clay mineral shown in Table 1 below was dispersed in a mixed liquid obtained by mixing the distilled water and glycerin in the blending ratio shown in Table 1, to prepare an ultraviolet scattering agent of Example 2.

[0032] (Comparative Example 2) Zinc oxide was dispersed in a mixed liquid prepared by mixing the distilled water and glycerin in the blending ratio shown in Table 1, to prepare an ultraviolet scattering agent of Comparative Example 2.

[0033] (Comparative Example 3) Zinc oxide was dispersed in decamethylcyclopentasiloxane at the blending ratio shown in Table 1 to prepare an ultraviolet scattering agent of Comparative Example 3.

[0034] <Evaluation test> The following tests were carried out using the obtained ultraviolet scattering agents of Examples 1 to 7 and Comparative Examples 1 to 3. (Light transmittance measurement) The light transmittance was measured using an ultraviolet-visible spectrophotometer (UV-1800, manufactured by Shimadzu Corporation). 3 Each of the ultraviolet scattering agents of Examples 1 to 7 and Comparative Examples 1 to 3 was filled into a quartz cell (optical path length: 10 mm) up to 80% of the cell volume, and the light transmittance was measured in the wavelength range of 250 to 500 nm. Note that the dispersion medium of each ultraviolet scattering agent was used for baseline correction of this measurement. The measurement results are shown in Table 1 below and FIG. 1 (Examples 1 to 7 only).

[0035] (particle size) The particle size of the smectite in each of the ultraviolet scattering agents of Examples 1 to 7 and Comparative Example 1 was measured as the dispersed particle size (median size on a volume basis) using a laser diffraction / scattering particle size distribution analyzer LA-950V2 (manufactured by Horiba, Ltd.) The results are shown in Table 1 below.

[0036] [Table 1]

[0037] The UV scattering agent of Comparative Example 1, which contained montmorillonite with a large particle size, was able to block UV rays with wavelengths of 250 nm and 280 nm, but also showed low transmittance for visible light with a wavelength of 500 nm. This is thought to be because the particle size of montmorillonite was somewhat large relative to the incident wavelength, resulting in reflection of not only UV rays but also visible light. The UV scattering agents of Comparative Examples 2 and 3, which contained zinc oxide, blocked transmission of both the visible light and UV rays, despite having sufficiently small primary particle sizes. This is thought to be because in both Comparative Examples 2 and 3, the zinc oxide aggregated to form coarse secondary particles, which reflected not only short-wavelength UV rays but also long-wavelength visible light. The UV scattering agents of Comparative Examples 1 to 3 all exhibited Mie scattering or wavelength-nonselective reflection, resulting in cloudy solutions. In contrast, in the UV scattering agents of Examples 1 to 7, in which each smectite was dispersed, the particle size was controlled to 350 nm or less (particle size was within the range of 40 to 130 nm), the transmittance of visible light with a wavelength of 500 nm was 30% or more, the transmittance of ultraviolet light with a wavelength of 280 nm was 70% or less, and the transmittance of ultraviolet light with a wavelength of 250 nm was 40% or less. It was also confirmed that the transmittance of each UV scattering agent decreased as the wavelength became shorter. Furthermore, in each UV scattering agent, the clay minerals maintained a stable dispersion state, Mie scattering did not occur, and the appearance was transparent.

[0038] Therefore, it was shown that the ultraviolet scattering agent of the present invention can sufficiently transmit visible light and effectively block ultraviolet rays by controlling the particle diameter of the dispersed clay minerals to 350 nm or less.< / ph>

Claims

1. An ultraviolet scattering agent comprising clay minerals with particle diameters of 350 nm or less dispersed in a liquid medium.

2. 2. The ultraviolet scattering agent according to claim 1, wherein the content of the clay mineral is 0.1 to 10% by mass.

3. 3. The ultraviolet scattering agent according to claim 2, wherein the light transmittance for visible light having a wavelength of 500 nm is 30% or more, the light transmittance for ultraviolet light having a wavelength of 280 nm is 40% or less, and the light transmittance for ultraviolet light having a wavelength of 280 nm is lower than the light transmittance for visible light having a wavelength of 500 nm.

4. 4. The ultraviolet scattering agent according to claim 3, wherein the clay mineral is selected from the group consisting of saponite, hectorite, and stevensite.

5. 5. The ultraviolet scattering agent according to claim 4, wherein the main interlayer cations of the clay mineral are sodium ions.

6. The ultraviolet scattering agent according to any one of claims 1 to 5, for use in cosmetics.

7. A cosmetic comprising the ultraviolet scattering agent according to any one of claims 1 to 5.

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