Oil-in-water emulsion cosmetics

Abstract

Provided is an oil-in-water-type emulsified cosmetic which contains pigment-grade hydrophobized particles and hydrophobized fine particles and can exhibit a good tone-up effect, etc., by uniformly applying hydrophobized particles to a skin surface.　An oil-in-water-type emulsified cosmetic according to the present disclosure contains a water-containing dispersion medium, and oil droplets dispersed in the dispersion medium, wherein: the dispersion medium contains a nonionic surfactant, a polyhydric alcohol, and pigment-grade hydrophobized particles having an average particle size of at least 300 nm; the oil droplets contain an oil fraction, a nonionic surfactant, and hydrophobized fine particles having an average particle size of at most 200 nm; and the oil fraction includes a volatile oil.

Description

[Technical Field]

[0001] The present disclosure relates to an oil-in-water emulsion cosmetic. [Background technology]

[0002] In the field of cosmetics, oil-in-water emulsion cosmetics containing hydrophobically treated particles have been developed.

[0003] Patent Document 1 discloses an oil-in-water emulsion sunscreen cosmetic that contains (A) an acrylic polymer; (B) an ultraviolet screening agent consisting of hydrophobically treated inorganic fine particles; (C) a nonionic surfactant that has an HLB value of 6.5 or less and is liquid or semi-solid at a temperature of 20°C; and (D) a nonionic surfactant that has an HLB value of 10 or more.

[0004] Patent Document 2 discloses an oil-in-water emulsion cosmetic that contains (A) 0.05 to 1 mass % of hydrophobically modified alkyl cellulose; (B) 5 to 40 mass % of an oil content; (C) 2.5 to 30 mass % of an ultraviolet scattering agent having a hydrophobic surface; and (D) an aqueous phase thickener with low salt tolerance, in which the ultraviolet scattering agent (C) is dispersed in the oil phase. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-123674 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-120682 Summary of the Invention [Problem to be solved by the invention]

[0006] In order to improve compatibility with the skin, particles incorporated into emulsion cosmetics may be subjected to hydrophobic treatment. In oil-in-water emulsion cosmetics, hydrophobically treated particles are generally incorporated into the oil phase (oil droplets).

[0007] When a cosmetic in this state is applied to the skin, the oil droplets tend to adsorb near the ridges of the skin, which have high surface activity, while the adsorbed oil droplets containing hydrophobic particles migrate to the sulci of the skin before the moisture dries, causing unevenness in the fine particles and resulting in problems such as powdering or creaking. For example, when relatively large hydrophobic pigment-grade particles are used to achieve a tone-up effect that brightens the skin color, this tendency becomes more pronounced, and there is a risk that the pigment-grade particles that have fallen off the surface may cause unevenness in the tone-up effect.

[0008] Therefore, a subject of the present disclosure is to provide an oil-in-water emulsion cosmetic containing pigment-grade hydrophobized particles and hydrophobized fine particles, which can be applied uniformly to the surface of the skin to achieve a good tone-up effect, etc. [Means for solving the problem]

[0009] <Aspect 1> a dispersion medium comprising water, and Oil droplets dispersed in the dispersion medium An oil-in-water emulsion cosmetic comprising: the dispersion medium contains a nonionic surfactant, a polyhydric alcohol, and pigment-grade hydrophobic treated particles having an average particle diameter of 300 nm or more; the oil droplets contain oil, a nonionic surfactant, and hydrophobized fine particles having an average particle diameter of 200 nm or less, The oil component includes a volatile oil. Oil-in-water emulsion cosmetics. <Aspect 2> A cosmetic preparation according to aspect 1, wherein the oil content is 20% by mass or more. <Aspect 3> 3. The cosmetic according to claim 1, wherein the volatile oil is contained in an amount of 10% by mass or more in the oil component. <Aspect 4> A cosmetic preparation according to any one of Aspects 1 to 3, wherein the nonionic surfactant has an HLB value of 10.0 to 16.0. <Aspect 5> A cosmetic preparation according to any one of Aspects 1 to 4, wherein the nonionic surfactant is a polyether-modified silicone. <Aspect 6> A cosmetic preparation according to aspect 5, wherein the mass ratio of the pigment-grade hydrophobized particles to the polyether-modified silicone having an HLB of 10.0 to 16.0 is 11 to 30. <Aspect 7> A cosmetic preparation according to any one of Aspects 1 to 6, wherein the oil component comprises at least one selected from polar oils and ultraviolet absorbers. <Aspect 8> A cosmetic according to Aspect 7, wherein the at least one selected from the polar oil and the ultraviolet absorber is contained in an amount of 10 mass % or more relative to the total amount of oil. <Aspect 9> A cosmetic preparation according to any one of aspects 1 to 8, wherein the hydrophobized fine particles are an ultraviolet scattering agent. [Effects of the Invention]

[0010] According to the present disclosure, it is possible to provide an oil-in-water emulsion cosmetic containing pigment-grade hydrophobized particles and hydrophobized fine particles, which can uniformly apply hydrophobized particles to the surface of the skin and thereby produce a favorable tone-up effect or the like. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1( a) is a schematic diagram of an oil-in-water emulsion cosmetic according to one embodiment of the present disclosure; FIG. 1( b) is a schematic diagram of the cosmetic immediately after application to the skin; FIG. 1( c) is a schematic diagram of the skin surface after the cosmetic has blended into the skin after the moisture has dried; FIG. 1( d) is a schematic diagram showing the state of the cosmetic after a further time has passed since the state in FIG. 1( c) when the cosmetic does not contain a volatile oil as an oil component; and FIG. 1( e) is a schematic diagram showing the state of the cosmetic after a further time has passed since the state in FIG. 1( c) when the cosmetic contains a volatile oil as an oil component. [Figure 2](a) is a schematic diagram of an oil-in-water emulsion cosmetic containing hydrophilic pigment-grade particles dispersed in an aqueous phase and oil droplets containing hydrophobically treated microparticles; (b) is a schematic diagram of the cosmetic immediately after application to the skin; and (c) is a schematic diagram of the skin surface after the water has dried. [Figure 3] (a) is a schematic diagram of an oil-in-water emulsion cosmetic containing oil droplets containing pigment-grade hydrophobized particles and hydrophobized microparticles, (b) is a schematic diagram of the cosmetic immediately after application to the skin, and (c) is a schematic diagram of the skin surface after the moisture has dried. [Figure 4] (a) is a schematic diagram of an oil-in-water emulsion cosmetic containing pigment-grade hydrophobized particles and hydrophobized microparticles dispersed in an aqueous phase, (b) is a schematic diagram of the cosmetic immediately after application to the skin, and (c) is a schematic diagram of the skin surface after the water has dried. DETAILED DESCRIPTION OF THE INVENTION

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present disclosure is not limited to the following embodiments, and various modifications can be made within the scope of the present invention.

[0013] In the oil-in-water emulsion cosmetic of the present disclosure, a water-containing dispersion medium contains pigment-grade hydrophobized particles having an average particle size of 300 nm or more, oil droplets dispersed in this dispersion medium contain an oil component, a nonionic surfactant, a polyhydric alcohol, and hydrophobized fine particles having an average particle size of 200 nm or less, and the oil component contains a volatile oil.

[0014] Although not limited by the principle, the functional principle by which the cosmetic composition of the present disclosure can uniformly apply hydrophobized particles to the surface of the skin and can exhibit a tone-up effect and the like is believed to be as follows.

[0015] When preparing an emulsion cosmetic containing hydrophobized particles, the hydrophobized particles are generally blended into an oil phase due to their hydrophobicity. However, the present inventors have surprisingly found that when larger pigment-grade particles among the hydrophobized particles are blended into the aqueous phase and smaller hydrophobized fine particles are blended into the oil phase, and a volatile oil is used as the oil component, when an oil-in-water emulsion cosmetic containing these particles is applied to the skin, the particles are uniformly applied to the skin surface, and the tone-up effect and the like are improved.

[0016] When the oil-in-water emulsion cosmetic of the present disclosure is applied to the skin, the relatively large pigment-grade hydrophobically treated particles 40 and oil droplets are adsorbed onto the generally hydrophobic skin 50, as shown in Figure 1(b). It is believed that the oil 20 in the oil droplets then migrates from the skin ridges toward the skin grooves before the water in the cosmetic dries. Because the hydrophobic pigment-grade particles are compatible with oil, they are enveloped by the migrated oil without repelling it. As a result, it is believed that an oil film uniformly containing the hydrophobically treated microparticles 30 and the pigment-grade hydrophobically treated particles 40 is uniformly formed on the surface of the skin 50, as shown in Figure 1(c).

[0017] However, even if such an oil film is temporarily formed, if the oil 20 in the oil droplets does not contain volatile oil, the hydrophobized microparticles 30 and pigment-grade hydrophobized particles 40 may migrate through the oil film over time, resulting in uneven particle distribution in the skin's sulcus, as shown in Figure 1(d), and problems such as grain removal or squeakiness. On the other hand, if the oil 20 in the oil droplets contains volatile oil, the volatile oil volatilizes over time, reducing the amount of oil in the oil film, making it difficult for these particles to migrate through the oil film. As a result, these particles are believed to be able to uniformly adsorb and remain on the skin surface, as shown in Figure 1(e). Furthermore, if the oil contains both volatile and non-volatile oils, as the volatile oil volatilizes and the amount of oil in the oil film decreases, the non-volatile oil itself is believed to be attracted to the particles on the skin surface and remain there. As a result, the migration of non-volatile oil is suppressed, resulting in the formation of a uniform oil film.

[0018] As a result, the cosmetic composition of the present disclosure can satisfactorily exhibit the functions provided by the pigment-grade hydrophobized particles and hydrophobized microparticles, such as the tone-up function and UV scattering function. Additionally, the cosmetic composition of the present disclosure can incorporate nonvolatile and organic UV absorbers as oil components into the oil film, and the formation of a uniform oil film containing these UV absorbers can also contribute to improving the UV protection effect (SPF). Dispersing pigment-grade hydrophobized particles in the outer phase (aqueous phase) can improve the SPF more than dispersing them in the inner phase (oil phase).

[0019] Furthermore, even if the hydrophobic treated microparticles aggregate and become coarse within the oil droplets, the degree of coarsening is less than that caused by aggregation of pigment-grade hydrophobic treated particles, and therefore it is thought that adverse effects such as color unevenness due to the aggregated hydrophobic treated microparticles are unlikely to occur.

[0020] On the other hand, in the case of an emulsion cosmetic containing hydrophilic pigment-grade particles 45 in an aqueous phase, as shown in Figure 2, the hydrophilic pigment-grade particles 45 tend to repel oil that has migrated therein, making it difficult to form a uniform oil film containing hydrophobically treated microparticles 30 and hydrophilic pigment-grade particles 45. In addition to being poorly compatible with hydrophobic skin, the hydrophilic pigment-grade particles are not applied to the skin surface together with the oil film, and are therefore likely to flake off or produce a powdery feeling. As a result, when such a cosmetic is applied to the skin surface, areas where the hydrophobically treated microparticles are locally present or areas where the pigment-grade particles have fallen off the skin are created, making it unlikely that the functions provided by the hydrophobically treated microparticles and pigment-grade particles (e.g., tone-up function, UV scattering function) will be fully realized.

[0021] In the case of an emulsion cosmetic containing both hydrophobically treated microparticles 30 and pigment-grade hydrophobically treated particles 40 in oil droplets, as shown in Figure 3, it is believed that the particles are more likely to aggregate within the oil droplets. In particular, aggregation of pigment-grade hydrophobically treated particles is highly likely to cause color unevenness or uneven toning. Even if only the hydrophobically treated microparticles 30 in Figure 3 were dispersed in the aqueous phase instead of the oil phase, the pigment-grade hydrophobically treated particles within the oil droplets would be prone to aggregation, and therefore emulsion cosmetics containing hydrophobically treated microparticles in the aqueous phase and pigment-grade hydrophobically treated particles in the oil phase would also be likely to suffer from defects such as color unevenness or uneven toning.

[0022] Furthermore, if hydrophobized fine particles and pigment-grade hydrophobized particles are simultaneously encapsulated in oil droplets, even if a cosmetic containing such oil droplets is applied to the skin, the oil will be attracted by both hydrophobized particles, and the oil will not spread as shown in Figure 1. Instead, both particles will be locally positioned on the skin surface, and it is thought that the functions of both particles will not be fully exerted.

[0023] 4, in the case of an emulsion cosmetic containing hydrophobized microparticles 30 and pigment-grade hydrophobized particles 40 in an aqueous phase, the hydrophobized particles are difficult to disperse in the aqueous phase to begin with, and therefore the two particles are likely to aggregate in the aqueous phase. As a result, the aggregated particles are located on the skin surface, which is likely to cause problems such as uneven color or uneven toning, and it is thought that the functions of the two particles cannot be fully exerted.

[0024] Furthermore, hydrophobic treated microparticles have a smaller particle size than pigment-grade hydrophobic treated particles, resulting in a larger specific surface area. As a result, dispersing hydrophobic treated microparticles in an aqueous phase requires a higher concentration of nonionic surfactant than dispersing only pigment-grade hydrophobic treated particles in an aqueous phase, which can easily cause a sticky feeling associated with nonionic surfactants.

[0025] <Oil-in-water emulsion cosmetics> <Dispersion medium> The dispersion medium in the oil-in-water emulsion cosmetic of the present disclosure contains water, pigment-grade hydrophobized particles, a nonionic surfactant, and a polyhydric alcohol.

[0026] (water) The amount of water to be added is not particularly limited, but from the viewpoint of emulsion stability and the like, it can be, for example, 30% by mass or more, 40% by mass or more, 50% by mass or more, 60% by mass or more, 70% by mass or more, or 80% by mass or more relative to the total amount of the cosmetic, and can be 90% by mass or less, 80% by mass or less, 70% by mass or less, or 60% by mass or less.

[0027] The water that can be used in the oil-in-water emulsion cosmetic of the present disclosure is not particularly limited, but can be water used in cosmetics, quasi-drugs, etc. For example, ion-exchanged water, distilled water, ultrapure water, tap water, etc. can be used.

[0028] (pigment-grade hydrophobic treated particles) There are no particular restrictions on the amount of pigment-grade hydrophobic treated particles that can be selected appropriately based on the desired effect (e.g., tone-up effect) depending on the application; for example, the amount can be 0.5% by mass or more, 1.0% by mass or more, or 1.5% by mass or more, and can be 15% by mass or less, 12% by mass or less, 10% by mass or less, 8.0% by mass or less, 6.0% by mass or less, or 5.0% by mass or less, relative to the total amount of the cosmetic.

[0029] The cosmetic preparation of the present disclosure contains pigment-grade hydrophobized particles in a dispersion medium. Pigment-grade hydrophobized particles and the hydrophobized microparticles described below can be distinguished by their sizes. Specifically, pigment-grade hydrophobized particles refer to hydrophobized particles with an average particle diameter of 300 nm or more, while hydrophobized microparticles refer to hydrophobized particles with an average particle diameter smaller than that of pigment-grade hydrophobized particles, for example, an average particle diameter of 200 nm or less. The average particle diameters of the pigment-grade hydrophobized particles of the present disclosure and the hydrophobized microparticles described below may be the size of primary particles or agglomerated secondary particles, and can be calculated by static light scattering.

[0030] Pigment-grade hydrophobic treated particles with an average particle size of 300 nm or more can exhibit a tone-up effect, such as brightening skin color. The average particle size of the pigment-grade hydrophobic treated particles can be appropriately selected so as to obtain the desired tone-up effect, and can be, for example, 300 nm or more, 350 nm or more, or 400 nm or more. There is no particular upper limit to the average particle size of the pigment-grade hydrophobic treated particles, but it can be, for example, 800 nm or less, 700 nm or less, or 600 nm or less.

[0031] The hydrophobic treatment for pigment-grade hydrophobized particles is not particularly limited, and includes any treatment that modifies the surface of such particles with an organic compound to make them hydrophobic, such as silicone-based or silane-based treatment using methylhydrogenpolysiloxane, dimethylpolysiloxane, alkylsilane, etc.; fluorine-based treatment using perfluoroalkyl phosphate ester, perfluoroalcohol, etc.; titanate-based treatment using alkyl titanate, etc.; amino acid treatment using N-acylglutamic acid, etc.; and other treatments such as lecithin treatment, metal soap treatment, fatty acid treatment, alkyl phosphate ester treatment, etc. These can be used alone or in combination.

[0032] From the viewpoint of resistance to release from the particles, the hydrophobic treatment is preferably carried out using a reactive hydrophobic treatment agent such as silicone, a silane-based treatment agent, or a titanate-based treatment agent.

[0033] Examples of silicones that can be used as hydrophobic treatment agents include known silicones having a hydrogen-silicon bond, such as methylhydrogenpolysiloxane (dimethicone / methicone) copolymer. Other examples include triethoxysilylethyl polydimethylsiloxyethyl dimethicone and triethoxysilylethyl polydimethylsiloxyethyl hexyl dimethicone, which have an alkoxy group-silicon bond as a reactive group. Other examples include dimethylpolysiloxane.

[0034] Examples of the silane-based treatment agent include a silylating agent having an organic group introduced therein and a silane coupling agent, such as triethoxycaprylylsilane.

[0035] Examples of titanate-based treatment agents include titanium coupling agents such as alkyl titanates, pyrophosphate-type titanates, phosphorous-type titanates, and amino acid-type titanates.

[0036] From the viewpoints of skin affinity, cost, etc., the hydrophobic treatment agent is preferably applied to the particles in a proportion of 2% by mass or more, 3% by mass or more, or 5% by mass or more, 12% by mass or less, 10% by mass or less, or 8% by mass or less, based on the total amount of pigment-grade hydrophobic treated particles after treatment.

[0037] The type of particles constituting the pigment-grade hydrophobized particles is not particularly limited and can be appropriately selected so as to obtain the desired tone-up effect, etc. Examples of pigment-grade hydrophobized particles include inorganic particles, specifically inorganic oxide particles, such as titanium oxide particles, zinc oxide particles, and cerium oxide particles (sometimes referred to as "inorganic white pigments"). In addition, inorganic particles generally classified as pearlescent agents (lustrous pigments) or colorants can also be used as the pigment-grade hydrophobized particles of the present disclosure. Organic particles can also be used as the pigment-grade hydrophobized particles of the present disclosure. These can be used alone or in combination of two or more types.

[0038] In the present disclosure, the term "pearlescent agent" refers to particles that exhibit brilliance and do not include coloring materials. Pearling agents typically have a flat, flaky or scaly form. In addition, in the present disclosure, the term "coloring material" refers to a material that exhibits a color other than white, does not include a pearling agent, and does not exhibit brilliance but can cause cosmetics to develop color. From the perspective of tone-up effect, when a pearling agent is used, it is preferable to use it in combination with inorganic oxide particles such as the titanium oxide particles described above, and when a coloring material is used, it is preferable to use it in combination with inorganic oxide particles such as the titanium oxide particles described above and / or a pearling agent.

[0039] Examples of pearlescent agents include titanium mica (titanium mica), iron oxide-coated titanium mica, carmine-coated titanium mica, carmine- and ferric iron oxide-coated titanium mica, iron oxide- and carmine-treated titanium mica, ferric iron oxide-treated titanium mica, iron oxide- and ferric iron oxide-treated titanium mica, chromium oxide-treated titanium mica, black titanium oxide-treated titanium mica, acrylic resin-coated aluminum powder, silica-coated aluminum powder, titanium oxide-coated mica, titanium oxide-coated bismuth oxychloride, titanium oxide-coated talc, colored titanium oxide-coated mica, titanium oxide-coated synthetic mica, titanium oxide-coated silica, titanium oxide-coated alumina, titanium oxide-coated glass powder, polyethylene terephthalate-polymethyl methacrylate laminated film powder, bismuth oxychloride, fish scale foil, iron oxide-coated titanium oxide-coated mica such as red iron oxide-coated titanium oxide-coated mica, and hollow titanium oxide powder with silica sandwiched between the mica and titanium oxide coating layer. These are typically white or another color.

[0040] Colorless pearlescent agents can also be used. Examples of such pearlescent agents include those known as transparent pearlescent agents (transparent luster pigments). For example, pearlescent agents can be used that use glass particles as a base material and have a coating formed on the surface of the particles, the coating being made of a high refractive index material such as titanium dioxide.

[0041] As the coloring material, for example, an inorganic pigment can be used.

[0042] Examples of inorganic pigments include inorganic red pigments (e.g., iron oxide (red iron oxide), iron titanate, etc.); inorganic brown pigments (e.g., γ-iron oxide, etc.); inorganic yellow pigments (e.g., yellow iron oxide, ochre, etc.); inorganic black pigments (e.g., black iron oxide, low-order titanium oxide, etc.); inorganic purple pigments (e.g., manganese violet, cobalt violet, etc.); inorganic green pigments (e.g., chromium oxide, chromium hydroxide, cobalt titanate, etc.); inorganic blue pigments (e.g., ultramarine, iron blue, etc.); and metal powders (e.g., aluminum, gold, silver, copper, etc.).

[0043] (nonionic surfactants) The content of the nonionic surfactant in the oil-in-water emulsion cosmetic of the present disclosure is not particularly limited, and can be, for example, 0.03% by mass or more, 0.05% by mass or more, 0.07% by mass or more, or 0.1% by mass or more, relative to the total amount of the cosmetic, and can also be 3.0% by mass or less, 2.5% by mass or less, 2.0% by mass or less, 1.5% by mass or less, 1.0% by mass or less, or 0.5% by mass or less. Due to its performance, the nonionic surfactant is thought to be present in the dispersion medium, on the surface of pigment-grade hydrophobized particles, and at the interface of oil droplets (described below), but in the aqueous phase, it is thought to contribute to the dispersion stability of the pigment-grade hydrophobized particles.

[0044] The nonionic surfactant is not particularly limited, and may be, for example, a nonionic surfactant with an HLB of 10.0 or more, 12.0 or more, or 14.0 or more, or 16.0 or less, 15.5 or less, or 15.0 or less. Nonionic surfactants with such HLB values ​​can further improve the emulsion stability of oil droplets and the dispersion stability of pigment-grade hydrophobized particles in an aqueous phase. Among these, nonionic surfactants with an HLB of 14.0 to 16.0 are preferred. In some embodiments, the cosmetic composition of the present disclosure may also be used in combination with a nonionic surfactant with an HLB of less than 10.0, for example, an HLB of 9.0 or less or 8.5 or less, or 3.0 or more, 3.5 or more, or 4.0 or more. Here, HLB generally indicates the affinity of a surfactant for water and oil, and is a parameter known as the hydrophilic-lipophilic balance. This can be easily calculated using known calculation methods, such as the Griffin method.

[0045] The nonionic surfactant is not particularly limited, and examples thereof include polyoxyalkylene alkyl ethers, polyalkylene glycol fatty acid esters, POE hydrogenated castor oil derivatives, POE alkyl ethers, POE-POP alkyl ethers, PEG fatty acid esters, polyglycerin fatty acid esters, POE glycerin fatty acid esters, PEG glyceryl isostearate, and silicone surfactants. Other nonionic surfactants such as polyglyceryl-2 diisostearate and sorbitan sesquiisostearate can also be used. The nonionic surfactants can be used alone or in combination.

[0046] Examples of polyoxyalkylene alkyl ethers include polyoxyethylene behenyl ether and polyoxyethylene stearyl ether.

[0047] Examples of polyalkylene glycol fatty acid esters include polyethylene glycol monostearate and polyethylene glycol monooleate.

[0048] Examples of POE hydrogenated castor oil derivatives (PEG hydrogenated castor oils) include POE (20-100) hydrogenated castor oil derivatives, specifically POE (20) hydrogenated castor oil derivatives, POE (40) hydrogenated castor oil derivatives, POE (60) hydrogenated castor oil derivatives, and POE (100) hydrogenated castor oil derivatives.

[0049] Examples of POE alkyl ethers include POE (2) lauryl ether, POE (4.2) lauryl ether, POE (9) lauryl ether, POE (5.5) cetyl ether, POE (7) cetyl ether, POE (10) cetyl ether, POE (15) cetyl ether, POE (20) cetyl ether, POE (23) cetyl ether, POE (4) stearyl ether, POE (20) stearyl ether, POE (7) oleyl ether, POE (10) oleyl ether, and POE (15) oleyl ether. ether, POE(20) oleyl ether, POE(50) oleyl ether, POE(10) behenyl ether, POE(20) behenyl ether, POE(30) behenyl ether, POE(2)(C12-15) alkyl ether, POE(4)(C12-15) alkyl ether, POE(10)(C12-15) alkyl ether, POE(5) secondary alkyl ether, POE(7) secondary alkyl ether, POE(9) alkyl ether, POE(12) alkyl ether, etc.

[0050] Examples of POE·POP alkyl ethers include POE(1) polyoxypropylene (POP)(4) cetyl ether, POE(10)POP(4) cetyl ether, POE(20)POP(8) cetyl ether, POE(20)POP(6) decyltetradecyl ether, and POE(30)POP(6) decyltetradecyl ether.

[0051] Examples of PEG fatty acid esters include polyethylene glycol monolaurate (hereinafter abbreviated as PEG) (10), PEG monostearate (10), PEG monostearate (25), PEG monostearate (40), PEG monostearate (45), PEG monostearate (55), PEG monostearate (100), PEG monooleate (10), PEG distearate, and PEG diisostearate.

[0052] Examples of polyglycerol fatty acid esters include hexaglyceryl monolaurate, hexaglyceryl monomyristate, hexaglyceryl monostearate, hexaglyceryl monooleate, decaglyceryl monolaurate, decaglyceryl monomyristate, decaglyceryl monostearate, decaglyceryl monoisostearate, decaglyceryl monooleate, decaglyceryl distearate, and decaglyceryl diisostearate.

[0053] Examples of POE glycerin fatty acid esters include polyoxyethylene (POE) (5) glyceryl monostearate, POE (15) glyceryl monostearate, POE (5) glyceryl monooleate, and POE (15) glyceryl monooleate.

[0054] Examples of PEG glyceryl isostearate include PEG(8) glyceryl isostearate, PEG(10) glyceryl isostearate, PEG(15) glyceryl isostearate, PEG(20) glyceryl isostearate, PEG(25) glyceryl isostearate, PEG glyceryl(30) isostearate, PEG(40) glyceryl isostearate, PEG(50) glyceryl isostearate, and PEG(60) glyceryl isostearate.

[0055] Examples of silicone surfactants that can be used include polyether-modified silicones, such as PEG(3) dimethicone, PEG(7) dimethicone, PEG(9) dimethicone, PEG(10) dimethicone, PEG(12) dimethicone, PEG(9) methyl ether dimethicone, PEG(10) methyl ether dimethicone, PEG(11) methyl ether dimethicone, PEG(32) methyl ether dimethicone, and PEG(9) polydimethylsiloxyethyl dimethicone.

[0056] Among these, polyether-modified silicones are preferred, and more preferred than PEG(11) methyl ether dimethicone, from the viewpoints of emulsion stability of oil droplets and dispersibility of pigment-grade hydrophobic treated particles.

[0057] From the viewpoints of emulsion stability of oil droplets, dispersibility of pigment-grade hydrophobic treated particles, usability such as stickiness, etc., the mass ratio of pigment-grade hydrophobic treated particles to polyether-modified silicone having an HLB of 10.0 to 16.0 is preferably, for example, 11 or more, 12 or more, 13 or more, or 14 or more, and is preferably 30 or less, 28 or less, or 25 or less.

[0058] (Polyhydric alcohol) The content of polyhydric alcohol in the oil-in-water emulsion cosmetic of the present disclosure is not particularly limited, and from the viewpoint of tone-up properties, dispersion stability of pigment-grade hydrophobic treated particles, etc., it can be, for example, 1.5% by mass or more, 2.0% by mass or more, 2.5% by mass or more, or 3.0% by mass or more relative to the total amount of the cosmetic, with 3.5% by mass or more being preferred, 4.0% by mass or more being more preferred, and 4.5% by mass or more being even more preferred. The upper limit of the polyhydric alcohol content is not particularly limited, but can be 10% by mass or less, 8.0% by mass or less, 6.0% by mass or less, or 5.0% by mass or less. The polyhydric alcohol is present in the dispersion medium and on the surface of pigment-grade hydrophobic treated particles, and is thought to contribute to the dispersion stability of the pigment-grade hydrophobic treated particles, but it may also be contained in the oil droplets described below.

[0059] Examples of polyhydric alcohols include ethylene glycol, propylene glycol, 1,3-butylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, and polybutylene glycol. Among these, 1,3-butylene glycol is preferred from the viewpoint of dispersibility of pigment-grade hydrophobized particles. These may be used alone or in combination. Note that the term "polyhydric alcohol" in this disclosure does not include glycerin.

[0060] <Oil drop> The oil droplets serving as the oil phase or dispersed phase in the oil-in-water emulsion cosmetic contain oil, a nonionic surfactant, and hydrophobized microparticles with an average particle size of 200 nm or less. The nonionic surfactant may be the same as those described above. The oil droplets may also contain the polyhydric alcohol described above.

[0061] (oil content) There are no particular limitations on the oil content in the oil-in-water emulsion cosmetic of the present disclosure, and it can be, for example, 10% by mass or more, 12% by mass or more, 15% by mass or more, 17% by mass or more, 20% by mass or more, 22% by mass or more, or 25% by mass or more relative to the total amount of the cosmetic, and can also be 50% by mass or less, 40% by mass or less, 30% by mass or less, or 25% by mass or less.

[0062] Cosmetics containing a high level of oil, for example, 20% by mass or more, can increase the content of, for example, ultraviolet absorbers and hydrophobized microparticles as ultraviolet scattering agents, thereby further improving the ultraviolet protection effect (SPF).

[0063] The oil-in-water emulsion cosmetic of the present disclosure contains a volatile oil as the oil component. Here, "volatile" refers to a composition that exhibits a volatile content of more than 5% when left at atmospheric pressure and 105°C for 3 hours. From the viewpoint of uniform application of the pigment-grade hydrophobized particles and hydrophobized microparticles to the skin, the volatile content, which serves as an indicator of volatility, is preferably 10% or more, 20% or more, 40% or more, 50% or more, 60% or more, 80% or more, or 100%. Alternatively, the boiling point at 1 atmosphere (101.325 kPa) can be used as an indicator of volatility. From the viewpoint of uniform application of the pigment-grade hydrophobized particles and hydrophobized microparticles to the skin, this boiling point is preferably 250°C or less, 240°C or less, or 230°C or less, and is preferably 80°C or more, 100°C or more, 120°C or more, 150°C or more, or 160°C or more. In addition, in the present disclosure, "non-volatile" refers to a material that exhibits a volatile content of 5% or less when left at 105°C for 3 hours.

[0064] The volatile oil is not particularly limited, and examples thereof include volatile silicone oils and volatile hydrocarbon oils. The volatile oils may be used alone or in combination.

[0065] Examples of volatile silicone oils include volatile acyclic silicone oils and volatile cyclic silicone oils, with volatile acyclic silicone oils being preferred.

[0066] As the volatile acyclic silicone oil, for example, a volatile linear silicone oil or a volatile branched silicone oil can be used, with the volatile linear silicone oil being preferred.

[0067] Examples of volatile linear silicone oils include low-molecular-weight linear dimethylpolysiloxanes such as dimethylpolysiloxane with a viscosity of 0.65 cSt (sometimes referred to as "dimethicone"), dimethylpolysiloxane with a viscosity of 1 cSt, dimethylpolysiloxane with a viscosity of 1.5 cSt, and dimethylpolysiloxane with a viscosity of 2 cSt. Among these, from the viewpoint of uniform application of pigment-grade hydrophobic-treated particles and hydrophobic-treated microparticles to the skin, dimethylpolysiloxane with a viscosity of 1 cSt and dimethylpolysiloxane with a viscosity of 1.5 cSt are preferred. Here, these viscosities refer to kinematic viscosities in an atmosphere at 25°C.

[0068] Examples of volatile branched silicone oils include low molecular weight branched siloxanes such as methyl trimethicone, tris(trimethylsilyl)methylsilane, and tetrakis(trimethylsilyl)silane.

[0069] Volatile cyclic silicone oils include, for example, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecamethylcyclohexasiloxane.

[0070] Examples of volatile hydrocarbon oils include heptane, isododecane, isohexadecane, and isodecane. Of these, isododecane is preferred from the viewpoint of uniform application of the pigment-grade hydrophobic treated particles and hydrophobic treated microparticles to the skin.

[0071] There are no particular restrictions on the content of volatile oil in the oil-in-water emulsion cosmetic of the present disclosure, and, for example, from the viewpoint of uniformly applying the pigment-grade hydrophobized particles and hydrophobized microparticles to the skin, it is preferably 1% by mass or more, 2% by mass or more, 3% by mass or more, 4% by mass or more, 5% by mass or more, 6% by mass or more, 7% by mass or more, 8% by mass or more, 9% by mass or more, or 10% by mass or more of the total amount of the cosmetic, and is preferably 30% by mass or less, 25% by mass or less, or 20% by mass or less. Alternatively, the content of the volatile oil is preferably 10% by mass or more, 15% by mass or more, 17% by mass or more, 20% by mass or more, 25% by mass or more, 30% by mass or more, 35% by mass or more, 40% by mass or more, 45% by mass or more, or 50% by mass or more, based on the total amount of oil, and is preferably about 100% by mass or less, less than about 100% by mass, about 90% by mass or less, about 80% by mass or less, about 70% by mass or less, or about 60% by mass or less.

[0072] The oil-in-water emulsion cosmetic of the present disclosure may contain oils other than volatile oils, for example, non-volatile oils. Such oils are not particularly limited, and examples include oils commonly used in cosmetics, such as liquid oils, solid oils, waxes, hydrocarbon oils other than those mentioned above, silicone oils other than those mentioned above, and polar oils. When other oils (e.g., non-volatile oils) are used in combination with volatile oils, after the volatile oil volatilizes, the other oils can function as binders between the particles and the skin, thereby favorably immobilizing the particles to the skin. The other oils can be used alone or in combination of two or more. Here, some UV absorbers act as oils, particularly polar oils. Such UV absorbers can also be considered oils.

[0073] Examples of liquid oils and fats include avocado oil, camellia oil, turtle oil, macadamia nut oil, corn oil, mink oil, olive oil, rapeseed oil, egg yolk oil, sesame oil, persic oil, wheat germ oil, camellia oil, castor oil, linseed oil, safflower oil, cottonseed oil, perilla oil, soybean oil, peanut oil, tea seed oil, kaya oil, rice bran oil, Chinese tung oil, Japanese tung oil, jojoba oil, germ oil, and triglycerin.

[0074] Examples of solid fats and oils include cacao butter, coconut oil, horse fat, hardened coconut oil, palm oil, beef tallow, mutton tallow, hardened beef tallow, palm kernel oil, lard, beef bone fat, Japan wax kernel oil, hardened oil, beef trotter fat, Japan wax, and hardened castor oil.

[0075] Examples of waxes include beeswax, candelilla wax, cotton wax, carnauba wax, bayberry wax, Ibota wax, whale wax, montan wax, rice bran wax, lanolin, kapok wax, lanolin acetate, liquid lanolin, sugarcane wax, lanolin fatty acid isopropyl, hexyl laurate, reduced lanolin, jojoba wax, hard lanolin, shellac wax, POE lanolin alcohol ether, POE lanolin alcohol acetate, POE cholesterol ether, lanolin fatty acid polyethylene glycol, and POE hydrogenated lanolin alcohol ether.

[0076] Examples of hydrocarbon oils include liquid paraffin, ozokerite, squalane, pristane, paraffin, ceresin, squalene, petrolatum, microcrystalline wax, and olefin oligomers.

[0077] Examples of silicone oils include chain silicones such as dimethylpolysiloxane (dimethicone), methylphenylpolysiloxane (diphenylsiloxyphenyltrimethicone), and methylhydrogenpolysiloxane, each having a viscosity of 6 cSt or more.

[0078] As the polar oil, for example, a polar oil having an IOB of 0.10 or more can be used. Examples of such polar oils include isopropyl myristate (IOB value = 0.18), octyl palmitate (IOB value = 0.13), isopropyl palmitate (IOB value = 0.16), butyl stearate (IOB value = 0.14), hexyl laurate (IOB value = 0.17), myristyl myristate (IOB value = 0.11), decyl oleate (IOB value = 0.11), isononyl isononanoate (IOB value = 0.20), and isotridecyl isononanoate (IOB value = 0.11). OB value = 0.15), cetyl ethylhexanoate (IOB value = 0.13), pentaerythrityl tetraethylhexanoate (IOB value = 0.35), diethylhexyl succinate (IOB value = 0.32), dioctyl succinate (IOB value = 0.36), glycol distearate (IOB value = 0.16), glyceryl diisostearate (IOB value = 0.29), neopentyl glycol dicaprate (IOB value = 0.25), diisostearyl malate (IOB value = 0.28 ), Trimethylolpropane triisostearate (IOB value = 0.16), Glyceryl tri-2-ethylhexanoate (Triethylhexanoin) (IOB value = 0.35), Trimethylolpropane trioctanoate (IOB value = 0.33), Trimethylolpropane triisostearate (IOB value = 0.16), Diisobutyl adipate (IOB value = 0.46), N-Lauroyl-L-glutamic acid-2-octyldodecyl ester (IOB value = 0.29), Adipic acid Examples include 2-hexyldecyl acrylate (IOB value = 0.16), diisopropyl sebacate (IOB value = 0.40), ethylhexyl methoxycinnamate (IOB value = 0.28), 2-ethylhexyl palmitate (IOB value = 0.13), 2-ethylhexyl ethylhexanoate (IOB value = 0.2), triisostearin (IOB value = 0.16), PPG-3 dipivalate (IOB value = 0.52), and caprylic / capric triglyceride (IOB value = 0.33).

[0079] Examples of UV absorbers that can be considered to be oils include UV absorbers with an IOB of 0.10 or more, specifically organic UV absorbers such as ethylhexyl methoxycinnamate, octocrylene, polysilicone-15, t-butyl methoxydibenzoylmethane, ethylhexyl triazone, bisethylhexyloxyphenol methoxyphenyl triazine, diethylaminohydroxybenzoylhexyl benzoate, oxybenzone-3, methylenebisbenzotriazolyltetramethylbutylphenol, homosalate, and ethylhexyl salicylate. These UV absorbers can be used alone or in combination of two or more.

[0080] The IOB value of the polar oil and the UV absorber can be, for example, 0.11 or more, 0.12 or more, or 0.13 or more, and can be 0.50 or less, 0.45 or less, or 0.40 or less. Here, the IOB value is an abbreviation for Inorganic / Organic Balance, which is a value representing the ratio of inorganic value to organic value and serves as an index of the degree of polarity of an organic compound. Specifically, the IOB value is expressed as IOB value = inorganic value / organic value. The "inorganic value" and "organic value" are set according to the type of atom or functional group, such as 20 for one carbon atom in a molecule and 100 for one hydroxyl group. The IOB value of an organic compound can be calculated by adding up the "inorganic value" and "organic value" of all atoms and functional groups in the organic compound (see, for example, "Organic Conceptual Diagram - Fundamentals and Applications" by Yoshio Koda, pp. 11-17, Sankyo Publishing, 1984).

[0081] The cosmetic composition of the present disclosure can contain at least one oil selected from the above-mentioned polar oils and UV absorbers in a relatively high concentration. These oils can be present in an amount of 10% by mass or more, 15% by mass or more, 20% by mass or more, 25% by mass or more, 30% by mass or more, 35% by mass or more, 40% by mass or more, or 45% by mass or more relative to the total oil content. There are no particular upper limits for these oil contents, and they can be, for example, 90% by mass or less, 85% by mass or less, 80% by mass or less, 75% by mass or less, 70% by mass or less, 65% by mass or less, 60% by mass or less, 55% by mass or less, or 50% by mass or less.

[0082] (Hydrophobic treated particles) The amount of hydrophobized microparticles to be blended is not particularly limited and can be selected appropriately based on the desired effect (e.g., UV scattering effect) depending on the application. For example, the amount can be 0.5% by mass or more, 1.0% by mass or more, 1.5% by mass or more, 2.0% by mass or more, 2.5% by mass or more, 3.0% by mass or more, 3.5% by mass or more, 4.0% by mass or more, 4.5% by mass or more, or 5.0% by mass or more relative to the total amount of the cosmetic, and can also be 20% by mass or less, 17% by mass or less, 15% by mass or less, 13% by mass or less, 10% by mass or less, 8.0% by mass or less, 6.0% by mass or less, or 5.0% by mass or less.

[0083] Hydrophobized microparticles with an average particle size of 200 nm or less can exhibit, for example, an ultraviolet scattering effect. The average particle size of the hydrophobized microparticles can be appropriately selected based on the desired effect (e.g., ultraviolet scattering effect) depending on the application, and can be, for example, 200 nm or less, 180 nm or less, 150 nm or less, 120 nm or less, 100 nm or less, or 80 nm or less. There is no particular restriction on the lower limit of the average particle size of the hydrophobized microparticles, but it can be, for example, 10 nm or more, 20 nm or more, 30 nm or more, 40 nm or more, 50 nm or more, 60 nm or more, or 70 nm or more.

[0084] The hydrophobic treatment for the hydrophobic treated fine particles is not particularly limited, and for example, the same treatment as the hydrophobic treatment for the pigment-grade hydrophobic treated particles described above can be carried out.

[0085] The type of particles constituting the hydrophobic treated microparticles is not particularly limited and can be appropriately selected based on the desired effect (e.g., UV scattering effect) depending on the application. Examples include inorganic particles, specifically titanium oxide, zinc oxide, barium sulfate, iron oxide, talc, mica, sericite, kaolin, titanium mica, Prussian blue, chromium oxide, chromium hydroxide, silica, and cerium oxide. These can be used alone or in combination of two or more. When the hydrophobic treated microparticles are used as a UV scattering agent, it is preferable to use particles having a refractive index of 1.5 or more, such as zinc oxide particles or titanium oxide particles, from the viewpoint of optical properties, etc.

[0086] <Optional ingredients> The oil-in-water emulsion cosmetic of the present disclosure may be appropriately blended with various components as long as the effects of the present disclosure are not adversely affected. These components include additives typically found in cosmetics, such as anionic surfactants, cationic surfactants, amphoteric surfactants, humectants, thickeners, water-soluble polymers, oil-soluble polymers, film-forming agents such as silicone-modified polysaccharides, higher fatty acids such as isostearic acid, sequestering agents, lower alcohols such as ethanol, higher alcohols such as stearyl alcohol, various extracts, sugars, amino acids, organic amines, polymer emulsions, chelating agents, UV absorbers other than those mentioned above, pH adjusters, skin nutrients, vitamins, water-soluble agents applicable to pharmaceuticals, quasi-drugs, cosmetics, etc., buffers, anti-fading agents, preservatives, dispersants, propellants, organic powders, pigments other than those usable as the pearlescent agents and colorants (e.g., organic pigments), dyes, colorants, fragrances, etc.

[0087] <Viscosity of cosmetics> In some embodiments, the viscosity of the oil-in-water emulsion cosmetic of the present disclosure, measured under the conditions and using the apparatus described in the Examples below, immediately after preparation of the cosmetic can be 20,000 mPa·s or less, 15,000 mPa·s or less, or 10,000 mPa·s or less, or can be 500 mPa·s or more, 1,000 mPa·s or more, 1,500 mPa·s or more, 2,000 mPa·s or more, or 2,500 mPa·s or more. Such viscosity of the cosmetic immediately after preparation can be referred to as the "initial viscosity."

[0088] In some embodiments, the viscosity of the oil-in-water emulsion cosmetic of the present disclosure, measured one day after preparation using the conditions and apparatus described in the Examples below, can be 20,000 mPa·s or less, 15,000 mPa·s or less, or 10,000 mPa·s or less, or can be 500 mPa·s or more, 1,000 mPa·s or more, 1,500 mPa·s or more, 2,000 mPa·s or more, or 2,500 mPa·s or more. Such viscosity of the cosmetic one day after preparation can be referred to as the "storage viscosity."

[0089] <<Method for preparing oil-in-water emulsion cosmetic>> The method for preparing the oil-in-water emulsion cosmetic of the present disclosure is not particularly limited, and it can be prepared by known methods such as dispersion methods and aggregation methods.

[0090] The dispersion method is a method of mechanically breaking down clumps of the dispersed phase into smaller particles. Specifically, it is a method of emulsifying by utilizing the crushing force of an emulsifier, and examples of such methods include high-pressure emulsification, in which high shear force is applied using a high-pressure homogenizer.

[0091] The aggregation method is a colloid preparation method that utilizes surface chemistry characteristics, in which a uniformly dissolved state is made supersaturated by some means to produce a dispersed phase. Specific methods include HLB temperature emulsification, phase inversion emulsification, non-aqueous emulsification, D-phase emulsification, and liquid crystal emulsification.

[0092] <<Formulation of oil-in-water emulsion cosmetics>> The formulation of the oil-in-water emulsion cosmetic of the present disclosure is not particularly limited, and examples include liquid, emulsion, cream, gel, spray, mousse, etc. Here, in the present disclosure, "spray" can include mist-type spray, aerosol-type spray, etc.

[0093] <<Uses of oil-in-water emulsion cosmetics>> The oil-in-water emulsion cosmetic of the present disclosure can be applied evenly to the surface of the skin by applying hydrophobized particles and, optionally, an ultraviolet absorber, to achieve a favorable tone-up effect, etc. Therefore, the cosmetic of the present disclosure that can exhibit such performance can be used, for example, as a cosmetic to be applied by spreading it on the skin, etc. Here, cosmetic compositions to be applied to the skin can also include those known as topical skin preparations.

[0094] The product form of the cosmetics of the present disclosure is not particularly limited, but examples include facial cosmetics such as lotion, serum, emulsion, and pack; makeup cosmetics such as foundation, lipstick, and eye shadow; sunscreen cosmetics (sunscreen agents); body cosmetics; skin cleansers such as makeup removers and body shampoos; hair cosmetics such as hair liquids, hair tonics, hair conditioners, shampoos, rinses, and hair growth agents; ointments, etc. [Example]

[0095] The oil-in-water emulsion cosmetic of the present disclosure will be described in more detail below using examples, but the cosmetic of the present disclosure is not limited to these. Note that, hereinafter, unless otherwise specified, the blending amounts are expressed in mass %.

[0096] Examples 1 to 13 and Comparative Examples 1 to 6 The oil-in-water emulsion cosmetics obtained using the formulations shown in Tables 1 to 3 and the production methods described below were evaluated as follows, and the results are shown in Tables 1 to 3.

[0097] Evaluation Method (Tone-up rating) The prepared cosmetic was applied to the arm, allowed to dry, and then the arm was left hanging down toward the ground for 5 minutes. The surface to which the cosmetic was applied was then visually observed and the toning state was evaluated according to the following criteria. Here, grades A to B are considered to be acceptable, and grade C is considered to be unacceptable. In addition to the toning effect, this toning test can also indirectly evaluate whether the pigment-grade hydrophobic treated particles and hydrophobic treated microparticles are evenly applied to the skin surface. In other words, the order of C, B, and A indicates that the particles are evenly applied to the skin surface.

[0098] A: The brightness was consistent and an excellent tone-up effect was achieved. B: There was slight unevenness in brightness, but a good tone-up effect was achieved. C: There was a clear unevenness in brightness, and no good tone-up effect was obtained.

[0099] (Evaluation of particle dispersibility) The prepared cosmetic was placed in a 50 mL transparent sample tube (3 cm diameter) and stored at 25°C for 7 days. The dispersion state of the pigment-grade hydrophobic treated particles and hydrophobic treated fine particles was then visually observed and evaluated according to the following criteria.

[0100] A: No sediment of pigment-grade hydrophobic treated particles or hydrophobic treated fine particles was observed. B: A small amount of pigment-grade hydrophobic treated particles and hydrophobic treated fine particles was observed. C: Sediments of pigment-grade hydrophobic treated particles and hydrophobic treated fine particles were clearly observed.

[0101] (Rolling stability evaluation) The prepared cosmetic was placed in a 50 mL transparent sample tube (3 cm diameter), and the sample tube was rotated at 45 rpm for 4 hours in an atmosphere of 25°C. The aggregation state of the pigment-grade hydrophobic treated particles and hydrophobic treated fine particles was visually observed and evaluated according to the following criteria.

[0102] A: No colored stripes associated with aggregates of pigment-grade hydrophobic treated particles or hydrophobic treated fine particles were observed. B: Very slight color stripes associated with aggregates of pigment-grade hydrophobic treated particles and hydrophobic treated fine particles were observed. C: Slight color stripes associated with aggregates of pigment-grade hydrophobic treated particles and hydrophobic treated fine particles were observed. D: Colored stripes associated with aggregates of pigment-grade hydrophobic treated particles and hydrophobic treated fine particles were clearly observed.

[0103] (Evaluation of usability) The prepared cosmetics were applied to the skin by a panel of five experts, and evaluated in accordance with the following evaluation criteria for smoothness, stickiness, powdery feeling, etc. at the time of application, during application, and after application.

[0104] A: Five people answered that they felt a smooth feel when using the product without feeling any stickiness or powdery texture. B: 3 to 4 people answered that they felt a smooth feel when using the product without feeling any stickiness or powdery texture. C: 0 to 2 people answered that they felt a smooth feel when using the product without feeling any stickiness or powdery texture.

[0105] (Viscosity evaluation) The viscosity of the cosmetics was evaluated using a B-type viscometer (TVB-10 TVB viscometer, manufactured by Toki Sangyo Co., Ltd.) under conditions of rotor number 3, 30°C, and 12 rpm. The viscosity was measured one day after the cosmetics were prepared. The cosmetics of Comparative Examples 1 and 5 had poor particle dispersibility and precipitated, so the viscosity of these cosmetics was not measured.

[0106] <Method for manufacturing cosmetics> Oil-in-water emulsion cosmetics were produced by the following method using the formulations shown in Tables 1 to 3. Here, the numbers shown below correspond to the numbers on the left side indicating the names of the ingredients in the formulations in Tables 1 to 3.

[0107] Example 1 Materials No. 2 to No. 4 were added to a portion of the ion-exchanged water No. 1 and mixed uniformly, and then No. 5, a portion of No. 6, and materials No. 7 to No. 9 were mixed uniformly to obtain an aqueous phase part.

[0108] The materials Nos. 18 to 21 and the hydrophobic treated particles No. 28 were uniformly mixed to obtain an oil phase part.

[0109] The remaining ion-exchanged water from No. 1 was mixed uniformly with the remaining No. 6, the nonionic surfactant from No. 12, and the pigment-grade hydrophobic treated particles from No. 13 to obtain powder parts.

[0110] A mixed liquid was prepared by gradually adding the oil phase part to the aqueous phase part, followed by gradually adding the materials Nos. 22 to 27. Next, a dispersion of No. 11 silica in ethanol (No. 10) was gradually added to this mixed liquid, followed by gradually adding the powder part, and the mixture was uniformly dispersed using a dispenser to obtain the oil-in-water emulsion cosmetic of Example 1.

[0111] (Examples 2 to 7 and Comparative Examples 1 and 2) Oil-in-water emulsion cosmetics of Examples 2 to 7 and Comparative Examples 1 and 2 were obtained in the same manner as in Example 1, except that the formulation was changed as shown in Table 1.

[0112] (Comparative Example 3: A system in which pigment-grade hydrophilic particles are blended in the aqueous phase (external phase) and hydrophobic treated fine particles are blended in the oil phase (internal phase)) Materials No. 2 to No. 4 were added to a portion of the ion-exchanged water No. 1 and mixed uniformly, and then No. 5, a portion of No. 6, and materials No. 7 to No. 9 were mixed uniformly to obtain an aqueous phase part.

[0113] The materials Nos. 18 to 21 and the hydrophobic treated particles No. 28 were uniformly mixed to obtain an oil phase part.

[0114] The remaining ion-exchanged water from No. 1 was mixed uniformly with the remaining No. 6, the nonionic surfactant from No. 12, and the pigment-grade hydrophilic particles from No. 17 to obtain a powder part.

[0115] A mixed liquid was prepared by gradually adding the oil phase part to the aqueous phase part, followed by gradually adding the materials Nos. 22 to 27. Next, a dispersion of silica No. 11 in ethanol No. 10 was gradually added to this mixed liquid, followed by gradually adding the powder part, and the mixture was uniformly dispersed using a dispenser to obtain the oil-in-water emulsion cosmetic of Comparative Example 3.

[0116] (Comparative Example 4: System in which pigment-grade hydrophobic treated particles and hydrophobic treated fine particles are blended in the oil phase (internal phase)) Materials Nos. 2 to 4 were added to ion-exchanged water No. 1 and mixed uniformly, and then materials Nos. 5 to 9 and 12 were mixed uniformly to obtain an aqueous phase part.

[0117] The materials Nos. 18 to 21, the hydrophobic treated fine particles No. 28, and the pigment-grade hydrophobic treated particles No. 29 were uniformly mixed to obtain an oil phase part.

[0118] A mixed liquid was prepared by gradually adding the oil phase part to the aqueous phase part, and then gradually adding the materials Nos. 22 to 27. Next, a dispersion of silica No. 11 in ethanol No. 10 was gradually added to this mixed liquid, and the mixture was dispersed uniformly using a dispenser to obtain the oil-in-water emulsion cosmetic of Comparative Example 4.

[0119] (Comparative Example 5: System in which pigment-grade hydrophobic treated particles and hydrophobic treated fine particles are blended in the aqueous phase (external phase)) Materials No. 2 to No. 4 were added to a portion of the ion-exchanged water No. 1 and mixed uniformly, and then No. 5, a portion of No. 6, and materials No. 7 to No. 9 were mixed uniformly to obtain an aqueous phase part.

[0120] Materials Nos. 18 to 21 were mixed uniformly to obtain an oil phase part.

[0121] The remaining ion-exchanged water from No. 1 was uniformly mixed with the remaining No. 6, the nonionic surfactant from No. 12, the pigment-grade hydrophobic treated particles from No. 13, and the hydrophobic treated fine particles from No. 16 to obtain powder parts.

[0122] A mixed liquid was prepared by gradually adding the oil phase part to the aqueous phase part, followed by gradually adding the materials Nos. 22 to 27. Next, a dispersion of silica No. 11 in ethanol No. 10 was gradually added to this mixed liquid, followed by gradually adding the powder part, and the mixture was uniformly dispersed using a dispenser to obtain the oil-in-water emulsion cosmetic of Comparative Example 5.

[0123] (Examples 8 to 13 and Comparative Example 6) Oil-in-water emulsion cosmetics of Examples 8 to 13 and Comparative Example 6 were obtained in the same manner as Example 1, except for changing the formulation as shown in Table 3. The oil components of Nos. 24 to 27 were blended when preparing the oil phase part.

[0124] [Table 1]

[0125] <result> As is clear from Table 1, the cosmetics of Examples 1 to 7, which contained pigment-grade hydrophobic treated particles in the aqueous phase, hydrophobic treated microparticles in the oil phase, and volatile oil as the oil component, exhibited excellent tone-up performance, confirming that these cosmetics can uniformly apply an oil film containing pigment-grade hydrophobic treated particles, hydrophobic treated microparticles, and an ultraviolet absorber (oil) to the skin surface.

[0126] When comparing the cosmetics of Examples 1 and 5, it was found that the cosmetic of Example 1, in which the mass ratio of pigment-grade hydrophobized particles to the nonionic surfactant polyether-modified silicone was 29, was greater than 8, and was superior in tone-up properties and rolling stability, and was less likely to cause problems with usability, particularly stickiness. When comparing the cosmetics of Examples 5 and 6, it was also found that the cosmetic of Example 6, in which the mass ratio of pigment-grade hydrophobized particles to polyether-modified silicone was 11, was greater than 8, and was less likely to cause problems with stickiness. It is believed that this stickiness is due to the increased amount of nonionic surfactant used.

[0127] As can be seen from the results of Example 7, it was confirmed that polyhydric alcohols other than 1,3-butylene glycol also have excellent performance such as tone-up properties.

[0128] On the other hand, the cosmetic of Comparative Example 1, which contained hydrophobic treated microparticles with an average particle size of 100 nm in the aqueous phase, which are smaller than the pigment-grade hydrophobic treated particles, had particles that settled, and was unable to achieve good tone-up properties and usability.

[0129] Furthermore, when the cosmetic of Comparative Example 2, which contains hydrophobized microparticles with an average particle size of 260 nm in its aqueous phase, which are smaller than the pigment-grade hydrophobized particles, is compared with the cosmetic of Example 1, which contains pigment-grade hydrophobized particles with an average particle size of 300 nm in its aqueous phase, it is clear that the cosmetic of Comparative Example 2 is inferior in all performance aspects, including tone-up properties, particle dispersibility, rolling stability, and ease of use.

[0130] [Table 2]

[0131] <result> None of the cosmetic preparations of Comparative Example 3, in which pigment-grade hydrophilic particles were blended in the aqueous phase (external phase) and hydrophobically treated microparticles were blended in the oil phase (internal phase) as shown in Figure 2; the cosmetic preparation of Comparative Example 4, in which pigment-grade hydrophobically treated particles and hydrophobically treated microparticles were blended in the oil phase (internal phase) as shown in Figure 3; and the cosmetic preparation of Comparative Example 5, in which pigment-grade hydrophobically treated particles and hydrophobically treated microparticles were blended in the aqueous phase (external phase) as shown in Figure 4, were able to achieve good tone-up properties.

[0132] [Table 3]

[0133] <result> As is clear from the results of Comparative Example 6, it was confirmed that when a cosmetic composition containing only non-volatile oil and no volatile oil was applied to the skin and the moisture was dried, the particles moved and were not evenly applied to the skin, and therefore a good tone-up effect could not be obtained. On the other hand, it was found that a good tone-up effect could be obtained with a cosmetic composition containing volatile oil, regardless of the type of pigment-grade hydrophobic particles.

[0134] As is clear from a comparison of Example 1 and Example 10, it was found that increasing the proportion of volatile oil in the oil component improves the tone-up effect, rolling stability, and ease of use. A similar trend was observed in Examples 11 and 13, and it was confirmed that even in formulations containing pearlescent agents, increasing the proportion of volatile oil in the oil component improves the tone-up effect.

[0135] As is clear from a comparison between Examples 8 and 9, the use of a pearlescent agent in combination with inorganic oxide particles such as hydrophobized titanium oxide particles as pigment-grade hydrophobic particles provides improved tone-up properties compared to the use of a pearlescent agent alone. [Explanation of symbols]

[0136] 10 water 20 oil content 30 Hydrophobic treated particles 40 Pigment-grade hydrophobic treated particles 45 Hydrophilic pigment-grade particles 50 Skin

Claims

1. A dispersion medium containing water, and Oil droplets dispersed in the dispersion medium An oil-in-water emulsion cosmetic comprising: the dispersion medium contains a nonionic surfactant, a polyhydric alcohol, and pigment-grade hydrophobized particles having an average particle size of 300 nm or more; The oil droplets contain oil, a nonionic surfactant, and hydrophobized fine particles having an average particle diameter of 200 nm or less, The HLB of the nonionic surfactant is 10.0 to 16.0; The oil component includes a volatile oil, The content of the oil is 10% by mass or more based on the total amount of the cosmetic, and The content of the volatile oil is 10% by mass or more based on the total amount of oil. Oil-in-water emulsion cosmetic.

2. The cosmetic according to claim 1 , wherein the content of the oil is 20% by mass or more based on the total amount of the cosmetic.

3. The cosmetic preparation according to claim 1 or 2, wherein the nonionic surfactant is a polyether-modified silicone.

4. The cosmetic preparation described in claim 3, wherein the mass ratio of the pigment-grade hydrophobically treated particles to the polyether-modified silicone is 11 to 30.

5. The cosmetic preparation according to any one of claims 1 to 4, wherein the oil component comprises at least one selected from a polar oil and an ultraviolet absorber.

6. The cosmetic preparation according to claim 5 , wherein the at least one selected from the group consisting of polar oils and ultraviolet absorbers is contained in an amount of 10 mass % or more based on the total amount of oil.

7. The cosmetic preparation according to any one of claims 1 to 6, wherein the hydrophobically treated fine particles are an ultraviolet scattering agent.

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