Oil-in-water emulsion cosmetics

Abstract

To provide an oil-in-water emulsified cosmetic material that contains pigment-grade hydrophobized particles and is capable of realizing favorable water resistance and tone-up effect.SOLUTION: An oil-in-water emulsified cosmetic material comprises a water-containing dispersion medium and oil droplets dispersed in the dispersion medium. The dispersion medium contains a first polyether-modified silicone having an HLB of more than 10.0 and 18.0 or less, a lower alcohol, and pigment-grade hydrophobized particles. The oil droplets contain oil and a second polyether-modified silicone having an HLB of 10.0 or less.SELECTED DRAWING: Figure 1

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 having water-resistant properties have been developed.

[0003] Patent Document 1 discloses a water-resistant oil-in-water emulsion cosmetic that contains (A) 0.05 to 2 mass% succinoglycan, (B) 0.1 to 3 mass% of one or more hydrophobic powders selected from nylon resin powder, urethane resin powder, silicone rubber powder, and silicone resin powder, and (C) 1 to 50 mass% of hydrophobic-treated powder, wherein components (A) and (B) are contained in an external aqueous phase and component (C) is contained in an internal oil phase.

[0004] Patent Document 2 discloses a water-resistant oil-in-water emulsion cosmetic that contains (A) 0.1 to 10 mass% of a polyether-modified silicone having an HLB(Si) of 5 to 10, (B) 5 to 50 mass% or less of ethanol, (C) 0.01 to 3 mass% of a hydrophilic thickener, (D) 0.1 to 15 mass% or more of a polyol, and (E) a water-soluble whitening agent. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-286748 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-072085 Summary of the Invention [Problem to be solved by the invention]

[0006] In oil-in-water emulsion cosmetics, hydrophobically treated particles are generally incorporated into the oil phase (oil droplets). Because such hydrophobically treated particles have the ability to easily repel water, they may be able to impart water resistance to the cosmetic when applied to the skin.

[0007] Furthermore, for example, in order to achieve a tone-up effect that brightens the skin color, relatively large pigment-grade hydrophobic treated particles may be used as hydrophobic treated particles to be blended into oil-in-water emulsion cosmetics.

[0008] When an oil-in-water emulsion cosmetic containing such hydrophobically treated particles is applied to the skin, the oil droplets containing the hydrophobically treated particles tend to adsorb and remain near the skin's ridges or sulci, which have high surface activity, with the oil attracted by the particles. As a result, oil containing hydrophobically treated particles (e.g., pigment-grade hydrophobically treated particles) is difficult to apply evenly to the skin, which can result in poor water resistance or uneven skin tone.

[0009] Therefore, an object of the present disclosure is to provide an oil-in-water emulsion cosmetic containing pigment-grade hydrophobically treated particles that can exhibit good water resistance and a tone-up effect. [Means for solving the problem]

[0010] <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 comprises a first polyether-modified silicone having an HLB of more than 10.0 and not more than 18.0, a lower alcohol, and pigment-grade hydrophobized particles; The oil droplets contain an oil and a second polyether-modified silicone having an HLB of 10.0 or less. Oil-in-water emulsion cosmetics. <Aspect 2> Aspect 1. The cosmetic preparation according to aspect 1, wherein the second polyether-modified silicone is a polyether-modified silicone containing at least one selected from the group consisting of polyoxyethylene (POE) and polyoxypropylene (POP). <Aspect 3> The cosmetic according to aspect 1 or 2, wherein the second polyether-modified silicone is a polyether-modified silicone represented by the following formula 1: [ka] In formula 1, m is an integer from 50 to 1,000; n is an integer from 1 to 40, a is an integer from 5 to 50, b is an integer of 5 to 50. <Aspect 4> A cosmetic preparation according to any one of Aspects 1 to 3, wherein the pigment-grade hydrophobized particles have an average particle size of 250 nm or more. <Aspect 5> A cosmetic according to any one of Aspects 1 to 4, wherein the lower alcohol is contained in an amount of 5.0% by mass or more relative to the total amount of the cosmetic. <Aspect 6> A cosmetic preparation according to any one of aspects 1 to 5, wherein the dispersion medium further comprises a water-soluble thickener. <Aspect 7> 7. The cosmetic preparation according to any one of aspects 1 to 6, wherein the mass ratio of the pigment-grade hydrophobized particles to the first polyether-modified silicone is 10 or greater. <Aspect 8> A cosmetic preparation according to any one of aspects 1 to 7, wherein the absorbance integral ratio after the water resistance test is 100% or more compared to that before the water resistance test. [Effects of the Invention]

[0011] According to the present disclosure, it is possible to provide an oil-in-water emulsion cosmetic containing pigment-grade hydrophobized particles that can exhibit good water resistance and a tone-up effect. [Brief explanation of the drawings]

[0012] [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 this cosmetic when applied to the skin, and FIG. 1(c) is a schematic diagram of the cosmetic after it has been applied to the skin and brought into contact with water. [Figure 2] (a) is a schematic diagram of an oil-in-water emulsion cosmetic containing oil droplets containing pigment-grade hydrophobized particles, and (b) is a schematic diagram of this cosmetic when applied to the skin. DETAILED DESCRIPTION OF THE INVENTION

[0013] 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.

[0014] The oil-in-water emulsion cosmetic of the present disclosure comprises a water-containing dispersion medium and oil droplets dispersed in the dispersion medium, the dispersion medium comprising a first polyether-modified silicone having an HLB value of more than 10.0 and not more than 18.0, a lower alcohol, and pigment-grade hydrophobized particles, and the oil droplets comprise an oil and a second polyether-modified silicone having an HLB value of not more than 10.0.

[0015] Although not limited by the principle, the principle of action that enables the cosmetic composition of the present disclosure to exhibit good water resistance and tone-up effects is believed to be as follows.

[0016] When preparing an oil-in-water emulsion cosmetic containing hydrophobized particles, the hydrophobized particles are generally blended into an oil phase because they are hydrophobic. Also, from the viewpoint of improving water resistance, as described in Patent Document 1, the hydrophobized particles are generally blended into an oil phase.

[0017] However, the present inventors have surprisingly discovered that when pigment-grade hydrophobized particles are blended in the aqueous phase of an oil-in-water emulsion cosmetic together with a first polyether-modified silicone having a specific HLB value and a lower alcohol, and the oil droplets in the cosmetic contain an oil component and a second polyether-modified silicone having a specific HLB value, water resistance and a tone-up effect are improved when the cosmetic is applied to the skin. Furthermore, they have discovered that the water resistance and tone-up effect are further improved when the applied cosmetic is brought into contact with water.

[0018] As shown in Figure 1(a), the pigment-grade hydrophobized particles 20 of the present disclosure are believed to be dispersed in an oil-in-water emulsion cosmetic by the first polyether-modified silicone 10, which has a hydrophilic portion and a hydrophobic portion, being adsorbed to the particles 20 via the hydrophobic portion. On the other hand, in an oil-in-water emulsion cosmetic containing pigment-grade hydrophobized particles in the oil phase, the pigment-grade hydrophobized particles 20 are believed to exist in a densely packed state in the oil phase, as shown in Figure 2(a).

[0019] When an oil-in-water emulsion cosmetic containing pigment-grade hydrophobized particles in the oil phase is applied to the skin, it is believed that the pigment-grade hydrophobized particles 20 and oil 40 are densely packed together and adsorbed to and remain on the lipophilic skin, as shown in Figure 2(b).

[0020] On the other hand, in an oil-in-water emulsion cosmetic containing pigment-grade hydrophobized particles in the aqueous phase, the pigment-grade hydrophobized particles 20 are separated from one another by the first polyether-modified silicone 10 acting as a steric hindrance, and therefore, when such a cosmetic is applied to the skin, as shown in Figure 1(b), the pigment-grade hydrophobized particles 20 are more likely to be uniformly adsorbed and remain on the skin than in an oil-in-water emulsion cosmetic containing pigment-grade hydrophobized particles in the oil phase. As a result, the pigment-grade hydrophobized particles that contribute to water resistance and a tone-up effect are uniformly distributed on the skin, and therefore, the water resistance and tone-up effect are thought to be improved compared to an oil-in-water emulsion cosmetic containing pigment-grade hydrophobized particles in the oil phase.

[0021] Furthermore, when the cosmetic of the present disclosure is applied to the skin, the hydrophilic portions of the first polyether-modified silicone 10 adsorbed to the pigment-grade hydrophobized particles 20 are oriented outward, and it is believed that the oil 40 is unable to approach the pigment-grade hydrophobized particles 20 and is therefore spaced apart, as shown in Figure 1(b). As a result, it is believed that the pigment-grade hydrophobized particles 20 and the oil 40 exist separately on the skin. Because the first polyether-modified silicone 10 has a higher HLB and is more hydrophilic than the second polyether-modified silicone, it is believed that when water (e.g., sweat) comes into contact with the cosmetic on the skin in the state shown in Figure 1(b), the first polyether-modified silicone 10 adsorbed to the pigment-grade hydrophobized particles 20 is washed away with the water, exposing the hydrophobized surfaces of the pigment-grade hydrophobized particles 20. As a result, the pigment-grade hydrophobic treated particles 20 and the oil 40 become more compatible, and as the particles and the oil attract each other, a uniform film containing the pigment-grade hydrophobic treated particles 20 and the oil 40 is formed and covers the skin, which is believed to further improve water resistance and tone-up effects.

[0022] On the other hand, in oil-in-water emulsion cosmetics containing hydrophobically treated particles in the oil phase, the particles themselves are lipophilic, so polyether-modified silicone as a dispersant for such particles is not required; instead, the particles and oil in the cosmetics are already in a state of mutual compatibility, forming oil droplets. When such cosmetics are applied to the skin, the oil droplets containing the hydrophobically treated particles are believed to tend to adsorb relatively unevenly near the skin's ridges or sulci, which have high surface activity, as shown in Figure 2(b). Furthermore, unlike the case shown in Figure 1(b), particles in this state are already contained in the oil, so they do not form a uniform film even when contacted with water. As a result, it is believed that water resistance and tone-up effects are not further improved in oil-in-water emulsion cosmetics containing hydrophobically treated particles in the oil phase when contacted with water.

[0023] Furthermore, in some embodiments, the oil-in-water emulsion cosmetic of the present disclosure may have improved sun protection (SPF). It is known that large pigment-grade particles, such as pigment-grade titanium dioxide particles, can primarily protect against UV rays in the A region (UVA). Surprisingly, the oil-in-water emulsion cosmetic of the present disclosure, despite the use of pigment-grade hydrophobized particles, can also protect against UV rays in the B region (UVB), in addition to UV rays in the A region. As described above, this is believed to be because the pigment-grade hydrophobized particles can be more uniformly distributed on the skin in the oil-in-water emulsion cosmetic of the present disclosure, compared to conventional oil-in-water emulsion cosmetics that contain pigment-grade hydrophobized particles in the oil phase, resulting in improved scattering and reflection of UVA and UVB rays.

[0024] <Oil-in-water emulsion cosmetics> <Dispersion medium> The dispersion medium (aqueous phase) in the oil-in-water emulsion cosmetic of the present disclosure contains water, pigment-grade hydrophobized particles, a first polyether-modified silicone having an HLB of more than 10.0 and not more than 18.0, and a lower alcohol.

[0025] (water) The amount of water to be blended is not particularly limited, and for example, from the viewpoint of emulsion stability and the like, it can be 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, and can be 90% by mass or less, 80% by mass or less, 70% by mass or less, or 60% by mass or less, relative to the total amount of the cosmetic.

[0026] There are no particular limitations on the water that can be used in the oil-in-water emulsion cosmetic of the present disclosure, and for example, water used in cosmetics and quasi-drugs can be used, such as ion-exchanged water, distilled water, ultrapure water, and tap water.

[0027] (pigment-grade hydrophobic treated particles) The blending amount of the pigment-grade hydrophobic treated particles is not particularly limited and can be appropriately selected based on the desired effect depending on the application (e.g., water resistance, tone-up effect, SPF). The blending amount of the pigment-grade hydrophobic treated particles can be, for example, 0.5% by mass or more, 1.0% by mass or more, or 1.5% by mass or more relative to the total amount of the cosmetic, 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.

[0028] The average particle size of the pigment-grade hydrophobized particles can be appropriately selected so as to obtain the desired effect (e.g., water resistance, tone-up effect, SPF) depending on the application. The average particle size of the pigment-grade hydrophobized particles can be, for example, 250 nm or more, 300 nm or more, 350 nm or more, or 400 nm or more. Pigment-grade hydrophobized particles with an average particle size of 300 nm or more can preferably exhibit a tone-up effect that brightens skin color. The upper limit of the average particle size is not particularly limited, and can be, for example, 800 nm or less, 700 nm or less, or 600 nm or less. Here, the average particle size of the pigment-grade hydrophobized particles and the hydrophobized fine particles of optional components described below may be the size of primary particles or aggregated secondary particles, and can be calculated by static light scattering.

[0029] The hydrophobic treatment for pigment-grade hydrophobized particles is not particularly limited, and can be any treatment that modifies the surface of such particles with an organic compound to hydrophobize them, such as silicone-based or silane-based treatments using methylhydrogenpolysiloxane, dimethylpolysiloxane (dimethicone), alkylsilane, etc.; fluorine-based treatments using perfluoroalkyl phosphate esters, perfluoroalcohols, etc.; titanate-based treatments using alkyl titanates, etc.; amino acid treatments using N-acylglutamic acid, etc.; and other treatments such as lecithin treatment, metal soap treatment, fatty acid treatment, and alkyl phosphate ester treatment. The hydrophobization treatments can be used alone or in combination. The hydrophobization treatment can also be carried out using a hydrophobization treatment agent.

[0030] Examples of silicones 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.

[0031] 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.

[0032] 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.

[0033] The type of particles constituting the pigment-grade hydrophobized particles is not particularly limited and can be appropriately selected to obtain the desired effect (e.g., water resistance, tone-up effect, SPF) depending on the application. 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. The pigment-grade hydrophobized particles can be used alone or in combination of two or more types.

[0034] In the present disclosure, the term "pearlescent agent" refers to particles that exhibit a lustrous property 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 is capable of causing a cosmetic to develop color but does not exhibit a lustrous property. For example, from the perspective of achieving a 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.

[0035] 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.

[0036] Colorless pearlescent agents can also be used. Such pearlescent agents can be 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, which is made of a high refractive index material such as titanium oxide.

[0037] As the coloring material, for example, an inorganic pigment can be used.

[0038] 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.).

[0039] (First polyether-modified silicone) The first polyether-modified silicone can function as a dispersant for pigment-grade hydrophobically treated particles. The first polyether-modified silicone can be used alone or in combination of two or more kinds.

[0040] The first polyether-modified silicone has an HLB value of more than 10.0 and not more than 18.0, and has more hydrophilic properties than the second polyether-modified silicone described below. From the viewpoint of the uniformity of the film containing pigment-grade hydrophobized particles and oil on the skin after contact with water (sometimes simply referred to as "film uniformity"), the HLB value of the first polyether-modified silicone is preferably 10.5 or more, 11.0 or more, 11.5 or more, 12.0 or more, 12.5 or more, or 13.0 or more, and is preferably 17.5 or less, 17.0 or less, 16.5 or less, 16.0 or less, 15.5 or less, or 15.0 or less. Here, "HLB" generally refers to a value indicating affinity for water and oil, and is a parameter known as the hydrophilic-lipophilic balance. The HLB values of the first polyether-modified silicone and the second polyether-modified silicone described below can be easily determined by the Griffin method. Here, the HLB value according to the Griffin method can be calculated using the following formula 2: HLB value = 20 × total formula weight of hydrophilic parts / molecular weight … Equation 2

[0041] From the viewpoints of dispersibility of pigment-grade hydrophobic treated particles in the aqueous phase and film uniformity, the amount of the first polyether-modified silicone may be set to 0.01% by mass or more, 0.03% by mass or more, or 0.05% by mass or more, and may be set to 1.0% by mass or less, 0.8% by mass or less, 0.5% by mass or less, 0.3% by mass or less, or 0.2% by mass or less, relative to the total amount of the cosmetic.

[0042] From the viewpoints of dispersibility of the pigment-grade hydrophobic treated particles in the aqueous phase, film uniformity, and UV protection effect, the mass ratio of the pigment-grade hydrophobic treated particles to the first polyether-modified silicone is preferably, for example, 10 or more, 12 or more, 14 or more, 15 or more, or 17 or more, and is also preferably 70 or less, 65 or less, 60 or less, 55 or less, 50 or less, 45 or less, 40 or less, 35 or less, or 30 or less.

[0043] The type of the first polyether-modified silicone is not particularly limited as long as it has a specific HLB, and examples thereof include PEG-9 dimethicone, PEG-10 dimethicone, PEG-12 dimethicone, PEG-10 methyl ether dimethicone, PEG-11 methyl ether dimethicone, PEG / PPG-20 / 20 dimethicone, PEG / PPG-20 / 23 dimethicone, and PEG-17 dimethicone. Of these, PEG-11 methyl ether dimethicone is preferred.

[0044] (lower alcohol) The oil-in-water emulsion cosmetic of the present disclosure contains a second polyether-modified silicone, which will be described later, along with a lower alcohol. When such a cosmetic is applied to the skin, the lower alcohol in the cosmetic evaporates, causing the cosmetic on the skin to undergo a phase inversion from oil-in-water to water-in-oil (sometimes simply referred to as "phase inversion emulsification"), thereby enabling the cosmetic to exhibit excellent water resistance.

[0045] From the viewpoint of phase inversion emulsification and the resulting water resistance, the amount of lower alcohol to be blended may be 5.0% by mass or more, 8.0% by mass or more, or 10% by mass or more, and may be 50% by mass or less, 40% by mass or less, 30% by mass or less, 20% by mass or less, or 15% by mass or less, relative to the total amount of the cosmetic.

[0046] The type of lower alcohol is not particularly limited, and for example, a monohydric alcohol having an alkyl group with 1 to 5 carbon atoms is preferred, and a monohydric alcohol having an alkyl group with 1 to 3 carbon atoms is more preferred. Specific examples include ethanol, propanol, isopropanol, isobutyl alcohol, and t-butyl alcohol, and among these, ethanol is preferred. The lower alcohol can be used alone or in combination of two or more.

[0047] <Oil drop> The oil droplets serving as the oil phase or dispersed phase in the oil-in-water emulsion cosmetic contain an oil component and a second polyether-modified silicone having an HLB of 10.0 or less.

[0048] (oil content) The oil content in the oil-in-water emulsion cosmetic of the present disclosure is not particularly limited, and, for example, from the standpoint of water resistance, film uniformity, and the like, can be 1.0% by mass or more, 2.0% by mass or more, 3.0% by mass or more, 5.0% by mass or more, 7.0% by mass or more, 10% by mass or more, 15% by mass or more, 20% by mass or more, 25% by mass or more, or 30% 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, 20% by mass or less, 15% by mass or less, or 10% by mass or less.

[0049] Cosmetics containing a high oil content, for example, 20% by mass or more, can increase the content of, for example, ultraviolet absorbers and optional hydrophobic treated microparticles, which can be blended into the oil phase, and therefore can further improve the ultraviolet protection effect (SPF).

[0050] The type of oil is not particularly limited, and for example, volatile oils and non-volatile oils can be used. The oils can be used alone or in combination. Here, "volatile" refers to an oil that exhibits a volatile content of more than 5% when left at 105°C under atmospheric pressure for 3 hours. From the viewpoint of film uniformity, 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 film uniformity, the 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.

[0051] 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.

[0052] Examples of volatile silicone oils include volatile acyclic silicone oils and volatile cyclic silicone oils, with volatile acyclic silicone oils being preferred.

[0053] As the volatile acyclic silicone oil, for example, a volatile linear silicone oil and a volatile branched silicone oil can be used, of which the volatile linear silicone oil is preferred.

[0054] 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, dimethylpolysiloxane with a viscosity of 1 cSt and dimethylpolysiloxane with a viscosity of 1.5 cSt are preferred from the viewpoint of film uniformity, etc. Here, these viscosities refer to kinematic viscosities in an atmosphere at 25°C.

[0055] Examples of volatile branched silicone oils include low molecular weight branched siloxanes such as methyl trimethicone, tris(trimethylsilyl)methylsilane, and tetrakis(trimethylsilyl)silane.

[0056] Volatile cyclic silicone oils include, for example, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecamethylcyclohexasiloxane.

[0057] Examples of volatile hydrocarbon oils include heptane, isododecane, isohexadecane, and isodecane. Among these, isododecane is preferred from the viewpoint of film uniformity.

[0058] The amount of volatile oil in the oil content can be, for example, 0% by mass or more, 5% by mass or more, 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, and can be 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, relative to the total oil content. In this case, the remaining oil content can be non-volatile oil.

[0059] In addition to the above-mentioned volatile oils, examples of oils 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 fixing the particles to the skin. The other oils can be used alone or in combination of two or more. Here, some ultraviolet absorbers act as oils, particularly polar oils. Such ultraviolet absorbers can also be considered oils.

[0060] 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.

[0061] Examples of solid fats and oils include cocoa 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 foot fat, Japan wax, and hardened castor oil.

[0062] Examples of waxes include beeswax, candelilla wax, cotton wax, carnauba wax, bayberry wax, ivory wax, spermaceti, montan wax, rice bran wax, lanolin, kapok wax, acetated lanolin, 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.

[0063] Examples of hydrocarbon oils include liquid paraffin, ozokerite, squalane, pristane, paraffin, ceresin, squalene, petrolatum, microcrystalline wax, and olefin oligomers.

[0064] Examples of silicone oils include chain silicones such as dimethylpolysiloxane (dimethicone), methylphenylpolysiloxane (diphenylsiloxyphenyltrimethicone), and methylhydrogenpolysiloxane, all of which have a viscosity of 6 cSt or more.

[0065] 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 2-Hexyldecyl (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).

[0066] 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.

[0067] 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).

[0068] (Second polyether-modified silicone) The second polyether-modified silicone can function as an emulsifier. The second polyether-modified silicone can be used alone or in combination of two or more types.

[0069] The second polyether-modified silicone has an HLB of 10.0 or less and has more lipophilic properties than the first polyether-modified silicone described above. From the viewpoint of phase inversion emulsification and the associated water resistance, the HLB of the second polyether-modified silicone is preferably 9.0 or less, 8.0 or less, 7.0 or less, 6.0 or less, or 5.0 or less. There is no particular restriction on the lower limit of the HLB, and it can be, for example, 1.0 or more, 1.5 or more, or 2.0 or more.

[0070] From the viewpoint of phase inversion emulsification and the associated water resistance, the blending amount of the second polyether-modified silicone can be set to 0.1% by mass or more, 0.5% by mass or more, 1.0% by mass or more, 1.5% by mass or more, or 2.0% by mass or more, and can be set to 10% by mass or less, 8.0% by mass or less, or 5.0% by mass or less, relative to the total amount of the cosmetic.

[0071] The second polyether-modified silicone may be, for example, a polyether-modified silicone having a weight-average molecular weight of 50,000 or more and containing at least one selected from the group consisting of polyoxyethylene (POE) and polyoxypropylene (POP).

[0072] The weight average molecular weight of the polyether-modified silicone may be 50,000 or more, 55,000 or more, 60,000 or more, 65,000 or more, or 70,000 or more, and may be 500,000 or less, 400,000 or less, 300,000 or less, 200,000 or less, or 100,000 or less. Here, the weight average molecular weight refers to the number average molecular weight in terms of polystyrene as measured by gel permeation chromatography.

[0073] An example of such a polyether-modified silicone is the polyether-modified silicone represented by the following formula 1: [ka]

[0074] In formula 1, m is an integer of 50 to 1,000, and the numerical range of m can be selected from integers of 50 or more, 70 or more, 100 or more, 120 or more, 150 or more, or 200 or more, 1,000 or less, 800 or less, 500 or less, or 300 or less.

[0075] In formula 1, n is an integer from 1 to 40, and the numerical range of n can be selected from integers of 1 or more, 3 or more, 5 or more, 7 or more, or 10 or more, 40 or less, 35 or less, 30 or less, 25 or less, or 20 or less.

[0076] The ratio of m to n (m:n) is preferably from 200:1 to 5:1, and particularly preferably from 60:1 to 15:1.

[0077] In formula 1, a is an integer of 5 to 50, and the numerical range of a can be selected from integers of 5 or more, 7 or more, or 10 or more, and 50 or less, 45 or less, 40 or less, 35 or less, 30 or less, 25 or less, or 20 or less.

[0078] In formula 1, b is an integer of 5 to 50, and the numerical range of b can be selected from integers of 5 or more, 7 or more, or 10 or more, and 50 or less, 45 or less, 40 or less, 35 or less, 30 or less, 25 or less, or 20 or less.

[0079] The content of polyoxyalkylene groups in the molecule of Formula 1 is not particularly limited, but from the viewpoint of phase inversion emulsification, etc., it is preferably 20% by mass or more, more than 20% by mass, or 25% by mass or more of the total molecular weight, and is preferably 50% by mass or less, 40% by mass or less, 35% by mass or less, or 30% by mass or less.

[0080] Specific examples of the second polyether-modified silicone include PEG / PPG-19 / 19 dimethicone, PEG / PPG-20 / 22 butyl ether dimethicone, PEG / PPG-20 / 20 dimethicone, and PEG / PPG-30 / 10 dimethicone.

[0081] <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. Examples of such components include additives typically found in cosmetics, such as anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants, moisturizers, water-soluble thickeners, oil-soluble thickeners, water-soluble polymers, oil-soluble polymers, film-forming agents such as silicone-modified polysaccharides, higher fatty acids such as isostearic acid, sequestering agents, higher alcohols such as stearyl alcohol, polyhydric alcohols, various extracts, sugars, amino acids, organic amines, polymer emulsions, chelating agents, UV absorbers other than those listed above, pH adjusters, skin nutrients, vitamins, water-soluble agents applicable to pharmaceuticals, quasi-drugs, cosmetics, etc., buffers, anti-fading agents, preservatives, dispersants, propellants, fillers, pigments other than those usable as the pearlescent agents and colorants (e.g., organic pigments), hydrophobized fine particles, dyes, pigments, and fragrances. Optional ingredients can be blended into the oil phase and / or the aqueous phase and can be used alone or in combination. Some of these ingredients are described below.

[0082] (nonionic surfactants) In some embodiments, the oil-in-water emulsion cosmetic of the present disclosure comprises a nonionic surfactant.

[0083] Examples of nonionic surfactants 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, and PEG glyceryl isostearate. Other nonionic surfactants that can be used include polyglyceryl-2 diisostearate and sorbitan sesquiisostearate. These nonionic surfactants can be used alone or in combination.

[0084] Examples of polyoxyalkylene alkyl ethers include polyoxyethylene behenyl ether and polyoxyethylene stearyl ether.

[0085] Examples of polyalkylene glycol fatty acid esters include polyethylene glycol monostearate and polyethylene glycol monooleate.

[0086] 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.

[0087] 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, and POE(12) alkyl ether.

[0088] 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.

[0089] 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.

[0090] Examples of polyglycerin 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.

[0091] 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.

[0092] PEG glyceryl isostearate may include, for example, 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.

[0093] The content of the nonionic surfactant 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 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.

[0094] (Water-soluble thickener) In some embodiments, the oil-in-water emulsion cosmetic of the present disclosure includes a water-soluble thickener. Cosmetics including a water-soluble thickener can further improve emulsion stability.

[0095] The water-soluble thickener is not particularly limited as long as it is one that is used in cosmetics, and examples thereof include natural water-soluble thickeners, semi-synthetic water-soluble thickeners, synthetic water-soluble thickeners, and inorganic water-soluble thickeners.

[0096] Examples of natural water-soluble thickeners include plant-based polymers such as gum arabic, tragacanth gum, galactan, guar gum, carob gum, karaya gum, carrageenan, pectin, agar, quince seed (marmella), algae colloid (cassowia extract), starch (rice, corn, potato, wheat), and glycyrrhizic acid; microbial polymers such as xanthan gum, dextran, succinoglucan, and pullulan; and animal-based polymers such as collagen, casein, albumin, and gelatin.

[0097] Examples of semi-synthetic water-soluble thickeners include starch-based polymers such as carboxymethyl starch and methylhydroxypropyl starch; cellulose-based polymers such as methyl cellulose, nitrocellulose, ethyl cellulose, methylhydroxypropyl cellulose, hydroxyethyl cellulose, sodium cellulose sulfate, hydroxypropyl cellulose, sodium carboxymethyl cellulose (CMC), crystalline cellulose, and cellulose powder; and alginic acid-based polymers such as sodium alginate and propylene glycol alginate.

[0098] Examples of synthetic water-soluble thickeners include vinyl polymers such as polyvinyl alcohol, polyvinyl methyl ether, polyvinylpyrrolidone, and carboxyvinyl polymer (carbomer); polyoxyethylene polymers such as polyethylene glycol (weight average molecular weight: 1,500, 4,000, and 6,000); polyoxyethylene-polyoxypropylene copolymer polymers; acrylic polymers such as sodium polyacrylate, polyethyl acrylate, polyacrylamide, and acrylic acid-alkyl methacrylate copolymer; polyethyleneimine, and cationic polymers.

[0099] Examples of inorganic water-soluble thickeners include bentonite, AlMg silicate, laponite, hectorite, and silicic anhydride.

[0100] The amount of the water-soluble thickener may be, for example, from the viewpoint of emulsion stability, 0.01% by mass or more, 0.05% by mass or more, 0.1% by mass or more, or 0.2% by mass or more relative to the total amount of the cosmetic, and may be 3.0% by mass or less, 2.0% by mass or less, or 1.0% by mass or less.

[0101] (Polyhydric alcohol) In some embodiments, the oil-in-water emulsion cosmetic of the present disclosure includes a polyhydric alcohol, which can improve the transparency and stability of the oil-in-water emulsion cosmetic.

[0102] Examples of polyhydric alcohols include ethylene glycol, propylene glycol, 1,3-butylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polybutylene glycol, and dynamite glycerin.

[0103] The amount of polyhydric alcohol may be, for example, from the viewpoint of emulsion stability, 0.1% by mass or more, 0.5% by mass or more, 1.0% by mass or more, 2.0% by mass or more, or 3.0% by mass or more relative to the total amount of the cosmetic, and may be 15% by mass or less, 10% by mass or less, or 7.0% by mass or less.

[0104] (Hydrophobic treated particles) In some embodiments, the oil-in-water emulsion cosmetic of the present disclosure contains hydrophobized microparticles. From the viewpoints of UV protection effect, emulsion stability, etc., it is preferable that the hydrophobized microparticles are incorporated into the internal oil phase. Here, the above-mentioned pigment-grade hydrophobized particles and hydrophobized microparticles can be distinguished by their size. In other words, pigment-grade hydrophobized particles refer to hydrophobized particles having a particle size larger than that of hydrophobized microparticles.

[0105] 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, 5.0% by mass or less, 3.0% by mass or less, 1.0% by mass or less, 0.5% by mass or less, or 0.1% by mass or less.

[0106] For example, hydrophobized microparticles with an average particle size of 200 nm or less can exhibit 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.

[0107] 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.

[0108] 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. The hydrophobic treated microparticles 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.

[0109] <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 25,000 mPa·s or less, 23,000 mPa·s or less, 20,000 mPa·s or less, or 19,000 mPa·s or less, or can be 1,000 mPa·s or more, 3,000 mPa·s or more, 5,000 mPa·s or more, 7,000 mPa·s or more, or 10,000 mPa·s or more. Such viscosity of the cosmetic immediately after preparation can be referred to as the "initial viscosity."

[0110] <Integrated absorbance after water resistance test> In some embodiments, the oil-in-water emulsion cosmetic of the present disclosure can exhibit an absorbance integral ratio after a water resistance test, measured using the conditions and apparatus described in the Examples below, of 100% or more, 102% or more, 105% or more, 107% or more, or 110% or more compared to before the water resistance test. There is no particular upper limit to the absorbance integral ratio, and it can be, for example, 130% or less, 125% or less, or 120% or less.

[0111] The uniformity of the film formed after applying a cosmetic to the skin or the like and contacting it with water can be indirectly determined by the integrated absorbance fraction after a water resistance test. This integrated absorbance fraction is the ratio of the integrated absorbance of a test sample after a water resistance test, which is prepared by spreading the cosmetic on a specific substrate and drying it, to the integrated absorbance of the test sample before the water resistance test. In other words, an increase in this integrated absorbance fraction means that the pigment-grade hydrophobic treated particles are more uniformly distributed on the skin after the water resistance test.

[0112] <<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.

[0113] 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 an example of such a method is a high-pressure emulsification method in which high shear force is applied using a high-pressure homogenizer.

[0114] 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.

[0115] <<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 thereof include liquid, emulsion, cream, gel, spray, and mousse. Here, in the present disclosure, "spray" can include mist-type sprays, aerosol-type sprays, etc.

[0116] <<Uses of oil-in-water emulsion cosmetics>> The oil-in-water emulsion cosmetic of the present disclosure can uniformly apply pigment-grade hydrophobized particles to the surface of the skin, thereby achieving good water resistance and a toning effect. Therefore, the cosmetic of the present disclosure, which can exhibit such properties, can be used, for example, as a cosmetic to be applied by spreading it on the skin, etc. The cosmetic of the present disclosure further improves its water resistance and toning effect when it comes into contact with water (e.g., sweat), and is therefore preferably used, for example, as a cosmetic to be applied by applying water after being applied to the skin, etc., or as a cosmetic that can come into contact with water (e.g., sweat, saliva, rainwater, seawater, pool water). Here, cosmetic compositions to be applied to the skin can also include those known as topical skin preparations.

[0117] The product form of the cosmetics of the present disclosure is not particularly limited, and examples thereof include facial cosmetics such as lotion, serum, emulsion, and pack; makeup cosmetics such as foundation, lipstick, and eye shadow; sunscreen cosmetics (sunscreens); body cosmetics; hair cosmetics such as hair liquid, hair tonic, hair conditioner, shampoo, rinse, and hair growth products; ointments, etc. In particular, the cosmetics of the present disclosure can be suitably used as sunscreen cosmetics (sunscreens) that may be exposed to water in a pool or the ocean after application to the skin, or as facial cosmetics, makeup cosmetics, or body cosmetics that may be exposed to moisture such as sweat or saliva. [Example]

[0118] 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 %.

[0119] Examples 1 to 6 and Comparative Examples 1 to 6 The oil-in-water emulsion cosmetics obtained by the formulation shown in Table 1 and the manufacturing method shown below were subjected to the following evaluations, and the results are shown in Table 1. Here, in the table, "O / W (aqueous phase)" refers to an oil-in-water emulsion cosmetic in which pigment-grade hydrophobized particles are contained in the aqueous phase, "O / W" refers to an oil-in-water emulsion cosmetic that does not contain particles, and "O / W (oil phase)" refers to an oil-in-water emulsion cosmetic in which pigment-grade hydrophobized particles are contained in the oil phase.

[0120] Evaluation Method (Tone-up rating) The prepared cosmetic was applied to the arm, the moisture was allowed to dry, and the surface to which the cosmetic was applied was visually observed to evaluate the state of toning according to the following criteria. Here, a rating of A is considered a pass, and ratings of B to C are considered a fail. In addition to the toning effect, this toning test can also indirectly evaluate whether the pigment-grade hydrophobic treated particles have been evenly applied to the skin surface. That is, it can be said that the pigment-grade hydrophobic treated particles have been evenly applied to the skin surface in the order of C, B, and A.

[0121] A: The brightness was consistent and an excellent tone-up effect was achieved. B: There was slight unevenness in brightness, and a good tone-up effect was not achieved. C: There was a clear unevenness in brightness, and no good tone-up effect was obtained.

[0122] (Integrated absorbance after water resistance test) The prepared cosmetic was applied to a measurement plate (S plate) (5 x 5 cm V-groove PMMA plate, SPF MASTER (trademark) PA01, manufactured by Shiseido Co., Ltd.) at 2 mg / cm 2 The solution was applied with a finger for 60 seconds, allowed to dry for 15 minutes, and then its absorbance in the wavelength range of 280 to 400 nm was measured using a Hitachi U-3500 automatic recording spectrophotometer. Glycerin, which has no UV absorption, was used as a control, and the absorbance was calculated using the following equation 3. In equation 3, T is the transmittance of the sample, and T0 is the transmittance of glycerin: Absorbance=-log(T / T0) …Equation 3

[0123] The plate used for the measurement was thoroughly immersed in water with a hardness of 50 to 500, and left in the water for 30 minutes while stirring at 300 rpm using a Three-One motor. The plate was then dried for 15 to 30 minutes until all water droplets on the surface disappeared, and the absorbance was measured again. The absorbance integral ratio (sometimes referred to as the "absorbance change ratio") was calculated from the integrated absorbance values (total values) before and after the water bath using the following formula 4. Here, an absorbance integral ratio of 100% or more indicates that the plate exhibits performance equal to or better than that before the water resistance test, and therefore has excellent water resistance. Absorbance integral rate (%) = integrated absorbance value after water bath × 100 / integrated absorbance value before water bath ... Equation 4

[0124] (Boost effect: UV protection effect) The absorbance integral ratio after the water resistance test was measured in the range of 280 to 400 nm, which corresponds to the UVA to UVB range. Based on these measurement results, the improvement (boosting ability) of UV protection effect was evaluated according to the following criteria. Here, grades A to C are considered to be pass, and grade D is considered to be fail. Furthermore, the boosting ability results can indirectly evaluate not only the UV protection effect but also whether the pigment-grade hydrophobic treated particles are evenly applied to the skin surface. In other words, it can be said that the pigment-grade hydrophobic treated particles are evenly applied to the skin surface in the order of D, C, B, and A.

[0125] A: The absorbance integral ratio was 110% or more. B: The absorbance integral ratio was 105% or more and less than 110%. C: The absorbance integral ratio was 100% or more and less than 105%. D: The absorbance integral rate was less than 100%.

[0126] (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 was then visually observed and evaluated according to the following criteria.

[0127] A: No sediment of pigment-grade hydrophobic treated particles was observed. B: A very small amount of pigment-grade hydrophobic treated particles was observed. C: A small amount of pigment-grade hydrophobic treated particles was observed. D: Sediment of pigment-grade hydrophobic treated particles was clearly observed.

[0128] (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 was visually observed and evaluated according to the following criteria.

[0129] A: No color stripes associated with agglomerates of pigment-grade hydrophobic treated particles were observed. B: Very slight color stripes associated with agglomerates of pigment-grade hydrophobic treated particles were observed. C: Slight color stripes due to aggregation of pigment-grade hydrophobic treated particles were observed. D: Color stripes associated with agglomerations of pigment-grade hydrophobic treated particles were clearly observed.

[0130] (Viscosity evaluation) The viscosity of the cosmetic immediately after preparation was evaluated using a B-type viscometer (TVB-type viscometer TVB-10, manufactured by Toki Sangyo Co., Ltd.) under conditions of rotor number 4, 30°C, and 12 rpm.

[0131] <Method for manufacturing cosmetics> An oil-in-water emulsion cosmetic was produced by the following method using the formulation shown in Table 1. Here, the numbers shown below correspond to the numbers on the left side of the formulation in Table 1, which indicate the names of the ingredients.

[0132] Example 1 The materials Nos. 2 to 12 were added to a portion of the ion-exchanged water No. 1 and mixed uniformly to obtain an aqueous phase part.

[0133] The materials Nos. 20 to 25 were mixed uniformly to obtain an oil phase part.

[0134] The remaining ion-exchanged water from No. 1 was mixed uniformly with the materials from No. 13, No. 16, and No. 17 to obtain powder parts.

[0135] The oil phase part was gradually added to the aqueous phase part, and then the powder part was gradually added, and the mixture was uniformly dispersed using a homomixer to obtain the oil-in-water emulsion cosmetic of Example 1.

[0136] (Examples 2 to 5 and Comparative Examples 2 to 5) Oil-in-water emulsion cosmetics of Examples 2 to 5 and Comparative Examples 2 to 5 were obtained in the same manner as in Example 1, except that the formulation was changed as shown in Table 1.

[0137] (Comparative Example 1) An oil-in-water emulsion cosmetic of Comparative Example 1 was obtained in the same manner as in Example 1, except that the formulation was changed to that shown in Table 1 and that no powder parts were used.

[0138] (Comparative Example 6) The materials Nos. 2 to 12 were added to the ion-exchanged water No. 1 and mixed uniformly to obtain an aqueous phase part.

[0139] Materials No. 20 to No. 26 were mixed uniformly to obtain an oil phase part.

[0140] The material No. 27 was gradually added to the oil phase part to prepare a mixed liquid. Next, this mixed liquid was gradually added to the aqueous phase part and uniformly dispersed using a homomixer to obtain the oil-in-water emulsion cosmetic of Comparative Example 6.

[0141] [Table 1]

[0142] <result> The results in Table 1 confirm that the oil-in-water emulsion cosmetics of Examples 1 to 5, which have the configuration of the present disclosure and contain pigment-grade hydrophobized particles in the aqueous phase, have excellent tone-up properties and water resistance.

[0143] The absorbance integral fractions after the water resistance test for the cosmetic of Comparative Example 1, which does not contain pigment-grade hydrophobic treated particles, and the cosmetic containing pigment-grade hydrophobic treated particles in the oil phase, were 97% and 99%, respectively, demonstrating relatively good results in terms of water resistance. This is thought to be because these cosmetic compositions also contain a lower alcohol and a second polyether-modified silicone, which causes phase inversion emulsification, which contributes to water resistance, after application to the skin. Therefore, if the lower alcohol is not used, or if another emulsifier that does not cause phase inversion emulsification is used instead of the second polyether-modified silicone, it is predicted that water resistance will deteriorate.

[0144] Looking at the results of the absorbance integral fraction after the water resistance test in Comparative Examples 1, 5, and 6, it was confirmed that when no pigment-grade hydrophobized particles were used, when non-hydrophobized pigment-grade particles were blended in the aqueous phase, or when pigment-grade hydrophobized particles were blended in the oil phase, no improvement in boosting properties, i.e., no increase in UV protection effect, was observed even when water was added to the cosmetic. On the other hand, in the case of the oil-in-water emulsion cosmetics of Examples 1 to 5, it was confirmed that the boosting properties were improved when water was added to the cosmetic.

[0145] Furthermore, it was found that the oil-in-water emulsion cosmetics of Examples 1 to 5 also had excellent rolling stability and particle dispersibility. [Explanation of symbols]

[0146] 10. First polyether-modified silicone 20 Pigment-grade hydrophobic treated particles 30 water 40 oil content

Claims

1. a dispersion medium comprising water, and Oil droplets dispersed in the dispersion medium An oil-in-water emulsion cosmetic comprising: the dispersion medium comprises a first polyether-modified silicone having an HLB of more than 10.0 and not more than 18.0, a lower alcohol, and pigment-grade hydrophobized particles; the oil droplets contain an oil component and a second polyether-modified silicone having an HLB of 10.0 or less, the mass ratio of the pigment-grade hydrophobized particles to the first polyether-modified silicone is 12 or more; and The HLB value is a value calculated from the following formula: Oil-in-water emulsion cosmetics. HLB value = 20 x sum of formula weights of hydrophilic parts / molecular weight

2. The cosmetic preparation according to claim 1, wherein the second polyether-modified silicone is a polyether-modified silicone containing at least one selected from the group consisting of polyoxyethylene (POE) and polyoxypropylene (POP).

3. The cosmetic according to claim 1 or 2, wherein the second polyether-modified silicone is a polyether-modified silicone represented by the following formula 1: 【Chemical 1】 In formula 1, m is an integer from 50 to 1,000; n is an integer from 1 to 40, a is an integer from 5 to 50, b is an integer from 5 to 50.

4. The cosmetic according to any one of claims 1 to 3, wherein the pigment-grade hydrophobic treated particles have an average particle size of 250 nm or more.

5. The cosmetic according to any one of claims 1 to 4, wherein the lower alcohol is contained in an amount of 5.0 mass% or more relative to the total amount of the cosmetic.

6. The cosmetic preparation according to any one of claims 1 to 5, wherein the dispersion medium further comprises a water-soluble thickener.

7. The cosmetic according to any one of claims 1 to 6, wherein the absorbance integral ratio after the water resistance test is 100% or more compared to before the water resistance test.

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