Oil-in-water emulsified cosmetic

Abstract

Provided is an oil-in-water emulsion cosmetic that exhibits good water resistance and a brightening effect, which contains pigment-grade hydrophobically treated particles. The oil-in-water emulsion cosmetic of the present disclosure contains a dispersion medium containing water, and oil droplets dispersed in the dispersion medium. The dispersion medium contains a first polyether-modified silicone having an HLB exceeding 10.0 and being 18.0 or less, a lower alcohol, and pigment-grade hydrophobically treated particles, and the oil droplets contain an oil component, and a second polyether-modified silicone having an HLB of 10.0 or less.

Description

Technical Field

[0001] This disclosure relates to water-in-oil emulsion cosmetics. Background Technology

[0002] In the field of cosmetics, water-in-oil emulsion cosmetics with water-resistant properties have been developed.

[0003] Patent Document 1 discloses an oil-in-water emulsion cosmetic with water-resistant properties, comprising (A) 0.05 to 2% by mass of succinyl polysaccharide, (B) 0.1 to 3% by mass of one or more hydrophobic powders selected from nylon resin powder, urethane resin powder, silicone rubber powder, and organosilicon resin powder, and (C) 1 to 50% by mass of hydrophobically treated powder, wherein components (A) and (B) are contained in the outer aqueous phase, and component (C) is contained in the inner oil phase.

[0004] Patent document 2 discloses a water-in-oil emulsion cosmetic with water-resistant properties, containing (A) 0.1 to 10% by mass of HLB(Si), 5 to 10% by mass of polyether-modified organosilicon, (B) 5 to 50% by mass of ethanol, (C) 0.01 to 3% by mass of a hydrophilic thickener, (D) 0.1 to 15% by mass of polyol or more, and (E) a water-soluble whitening agent.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2009-286748

[0008] Patent Document 2: Japanese Patent Application Publication No. 2012-072085 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] In water-in-oil emulsion cosmetics, hydrophobic particles are typically incorporated into the oil phase (oil droplets). Furthermore, these hydrophobic particles, due to their water-repellent properties, can sometimes impart water resistance when the cosmetic is applied to the skin.

[0011] In addition, for example, as hydrophobic particles blended into water-in-oil emulsion cosmetics to achieve a brightening effect that makes the skin color brighter, larger-sized pigment-grade hydrophobic particles are sometimes used.

[0012] If an oil-in-water emulsion cosmetic containing such hydrophobically treated particles is applied to the skin, the oil droplets containing the hydrophobically treated particles, in a state where the oil is pulled by these particles, are easily adsorbed and remain near the papules or grooves of the skin where surface activity is high. As a result, oil containing hydrophobically treated particles (such as pigment-grade hydrophobically treated particles) is not easily applied evenly to the skin, and therefore sometimes does not achieve good water resistance, or sometimes results in uneven brightening.

[0013] Therefore, the subject of this disclosure is to provide an oil-in-water emulsion cosmetic containing pigment-grade hydrophobic particles that exhibits good water resistance and brightening effect.

[0014] Methods for solving problems

[0015] Option 1

[0016] An oil-in-water emulsion cosmetic, comprising: Dispersion media containing water, and Oil droplets dispersed in the above dispersion medium, The aforementioned dispersion medium comprises a first polyether-modified silicone with an HLB value exceeding 10.0 and below 18.0, lower alcohols, and pigment-grade hydrophobic treated particles. The oil droplets mentioned above contain oil and a second polyether-modified silicone with an HLB of less than 10.0.

[0017] Option 2

[0018] According to the cosmetic material described in Scheme 1, the second polyether-modified silicone is a polyether-modified silicone containing at least one selected from polyethylene oxide (POE) and polypropylene oxide (POP).

[0019] Option 3

[0020] According to the cosmetic material described in Scheme 1 or 2, the aforementioned second polyether-modified organosilicon is a polyether-modified organosilicon as shown in Formula 1 below.

[0021] In Equation 1, m is an integer from 50 to 1,000. n is an integer from 1 to 40. a is an integer between 5 and 50. b is an integer between 5 and 50.

[0022] Option 4

[0023] According to any one of Schemes 1 to 3, the average particle size of the above-mentioned pigment-grade hydrophobic treated particles is 250 nm or more.

[0024] Option 5

[0025] The cosmetic material according to any one of Schemes 1 to 4 contains 5.0% by mass or more of the aforementioned lower alcohol relative to the total amount of the cosmetic material.

[0026] <Option 6>

[0027] According to any one of Schemes 1 to 5, the dispersion medium further comprises a water-soluble thickener.

[0028] <Option 7>

[0029] According to any one of Schemes 1 to 6, the mass ratio of the above-mentioned pigment-grade hydrophobic treated particles to the above-mentioned first polyether modified organosilicon is 10 or more.

[0030] <Option 8>

[0031] According to any one of Schemes 1 to 7, the cumulative absorbance fraction after the water resistance test is more than 100% compared with that before the water resistance test.

[0032] The effects of the invention

[0033] According to this disclosure, a water-in-oil emulsion cosmetic containing pigment-grade hydrophobic treated particles can be provided, which exhibits good water resistance and brightening effect. Attached Figure Description

[0034] Figure 1 (a) is a schematic diagram of an oil-in-water emulsion cosmetic according to an embodiment of the present disclosure; (b) is a schematic diagram of the cosmetic applied to the skin; and (c) is a schematic diagram of the cosmetic applied to the skin after contact with water.

[0035] Figure 2 (a) is a schematic diagram of an oil-in-water emulsion cosmetic containing oil droplets with pigment-grade hydrophobic treatment particles, and (b) is a schematic diagram of the cosmetic when applied to the skin. Detailed Implementation

[0036] The embodiments of this disclosure will now be described in detail. This disclosure is not limited to these embodiments, and various modifications can be made within the scope of the spirit of the invention.

[0037] The water-in-oil emulsion cosmetic disclosed herein comprises: a dispersion medium containing water, and oil droplets dispersed in the dispersion medium, wherein the dispersion medium comprises a first polyether-modified silicone with an HLB of more than 10.0 and less than 18.0, a lower alcohol, and pigment-grade hydrophobic treated particles, and the oil droplets comprise oil and a second polyether-modified silicone with an HLB of less than 10.0.

[0038] Although not limited by principle, the working principle of the cosmetic material disclosed herein that can exhibit good water resistance and brightening effect can be considered as follows.

[0039] In the case of obtaining an oil-in-water emulsion cosmetic containing hydrophobically treated particles, the hydrophobically treated particles are generally blended into the oil phase because they are hydrophobic. Furthermore, from the viewpoint of improving water resistance, as described in Patent Document 1, the hydrophobically treated particles are generally blended into the oil phase.

[0040] However, the inventors discovered that if pigment-grade hydrophobically treated particles are mixed with a first polyether-modified silicone and a lower alcohol having a specific HLB value in an aqueous phase in an oil-in-water emulsion cosmetic, and the oil droplets in the cosmetic contain oil and a second polyether-modified silicone with a specific HLB value, then surprisingly, the water resistance and brightening effect are improved when such a cosmetic is applied to the skin. It was further discovered that if water is brought into contact with the applied cosmetic, the water resistance and brightening effect are further improved.

[0041] It can be considered that the pigment-grade hydrophobic treated particles 20 disclosed herein are as follows: Figure 1 As shown in (a), the first polyether-modified silicone 10, having both hydrophilic and hydrophobic portions, is adsorbed onto the particles 20 via the hydrophobic portion and thus dispersed in the oil-in-water emulsion cosmetic. On the other hand, it can be considered that for oil-in-water emulsion cosmetics containing pigment-grade hydrophobically treated particles in the oil phase, such as... Figure 2 As shown in (a), the pigment-grade hydrophobic treated particles 20 exist in the oil phase in a tightly packed state.

[0042] It can be assumed that if a water-in-oil emulsion cosmetic containing pigment-level hydrophobic particles in its oil phase is applied to the skin, then... Figure 2 As shown in (b), the pigment-grade hydrophobic treated particles 20 and oil 40 are adsorbed and remain on the oil-loving skin in a tightly packed state.

[0043] On the other hand, it can be considered that for water-in-oil emulsion cosmetics containing pigment-grade hydrophobic treated particles in the aqueous phase, the pigment-grade hydrophobic treated particles 20 exist separately due to the steric hindrance effect of the first polyether-modified organosilicon 10. Therefore, if such a cosmetic is applied to the skin, it will be like... Figure 1As shown in (b), compared to oil-in-water emulsion cosmetics containing pigment-level hydrophobic treated particles in the oil phase, the pigment-level hydrophobic treated particles 20 are more easily and evenly adsorbed and retained on the skin. As a result, it can be considered that, because the pigment-level hydrophobic treated particles, which contribute to water resistance and brightening effects, are evenly distributed on the skin, the water resistance and brightening effects are improved compared to oil-in-water emulsion cosmetics containing pigment-level hydrophobic treated particles in the oil phase.

[0044] Furthermore, it can be assumed that if the cosmetic material of this disclosure is applied to the skin, the hydrophilic portion of the first polyether-modified organosilicon 10 adsorbed onto the pigment-grade hydrophobic treated particles 20 will be oriented outwards, thus... Figure 1 As shown in (b), the oil 40 is not easily accessible to the pigment-grade hydrophobic treated particles 20 and is thus separately disposed. As a result, it can be considered that the pigment-grade hydrophobic treated particles 20 and the oil 40 exist separately on the skin. It can be considered that the first polyether-modified silicone 10, due to its higher HLB content compared to the second polyether-modified silicone, is hydrophilic; therefore, if... Figure 1 (b) When water (e.g., sweat) comes into contact with cosmetics on the skin, the first polyether-modified silicone 10 adsorbed on the pigment-grade hydrophobic treated particles 20 is washed away along with the water, exposing the hydrophobic treated surface of the pigment-grade hydrophobic treated particles 20. As a result, it can be considered that the pigment-grade hydrophobic treated particles 20 and oil 40 easily blend, with the particles and oil pulling against each other to form a uniform film containing both pigment-grade hydrophobic treated particles 20 and oil 40, thus further improving water resistance and brightening effect.

[0045] On the other hand, for oil-in-water emulsion cosmetics containing hydrophobically treated particles in the oil phase, since the particles themselves are lipophilic, polyether-modified silicone as a dispersant for such particles is unnecessary. In the cosmetic, the particles and oil have already fused together to form oil droplets. Furthermore, it can be assumed that if such a cosmetic is applied to the skin, the oil droplets containing the hydrophobically treated particles will... Figure 2 As shown in (b), these particles tend to adhere less uniformly to papules or grooves in skin with high surface activity. Furthermore, particles in this state... Figure 1 The situation in (b) is different. Since the particles are already contained in the oil, a uniform film will not form even when in contact with water. As a result, it can be concluded that in water-in-oil emulsion cosmetics containing hydrophobically treated particles in the oil phase, water resistance and brightening effect will not be further improved even when in contact with water.

[0046] Furthermore, in several embodiments, the water-in-oil emulsion cosmetic of this disclosure can improve the UV protection effect (SPF). It is known that large pigment-grade particles, such as pigment-grade titanium dioxide particles, are primarily capable of protecting against UVA in region A. In the case of the water-in-oil emulsion cosmetic of this disclosure, even when using pigment-grade hydrophobic treated particles, it is unexpectedly not limited to region A but can also protect against UVB in region B. This can be attributed to the fact that, as described above, compared to conventional water-in-oil emulsion cosmetics where the oil phase contains pigment-grade hydrophobic treated particles, the pigment-grade hydrophobic treated particles can be uniformly distributed on the skin, thus improving the scattering and reflection properties of UVA and UVB.

[0047] Water-in-oil emulsion cosmetics

[0048] <Dispersion Medium>

[0049] The dispersion medium (aqueous phase) in the water-in-oil emulsion cosmetic disclosed herein comprises water, pigment-grade hydrophobically treated particles, a first polyether-modified silicone with an HLB of more than 10.0 and less than 18.0, and a lower alcohol.

[0050] (water)

[0051] There are no particular restrictions on the amount of water mixed in. For example, from the perspective of emulsification stability, it can be 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, or 80% or more relative to the total amount of cosmetics. Alternatively, it can be 90% or less, 80% or less, 70% or less, or 60% or less.

[0052] There are no particular limitations on the water that can be used in the water-in-oil emulsion cosmetics disclosed herein; for example, water used in cosmetics and pharmaceuticals can be used. Examples of water that can be used include, for instance, ion-exchanged water, distilled water, ultrapure water, and tap water.

[0053] (Pigment-grade hydrophobic treated particles)

[0054] There are no particular restrictions on the mixing amount of pigment-grade hydrophobic treated particles, and it can be appropriately selected based on the desired effect corresponding to the application (e.g., water resistance, brightening effect, SPF). The mixing amount of pigment-grade hydrophobic treated particles, relative to the total amount of cosmetics, can be 0.5% by mass or more, 1.0% by mass or more, or 1.5% by mass or more; alternatively, it 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.

[0055] The average particle size of the pigment-grade hydrophobic treated particles can be appropriately selected to obtain the desired effect (e.g., water resistance, brightening effect, SPF) corresponding to the application. For example, the average particle size of the pigment-grade hydrophobic treated particles can be 250 nm or more, 300 nm or more, 350 nm or more, or 400 nm or more. Pigment-grade hydrophobic treated particles with an average particle size of 300 nm or more can appropriately exhibit a brightening effect that makes skin color brighter. There is no particular limit to the upper limit of the average particle size; for example, it can be 800 nm or less, 700 nm or less, or 600 nm or less. Here, the average particle size of the pigment-grade hydrophobic treated particles in this disclosure, and the hydrophobic treated microparticles of any component described later, can be the size of primary particles or aggregated secondary particles, and can be calculated by static light scattering.

[0056] The hydrophobication treatment of pigment-grade particles is not particularly limited. Any treatment that modifies the surface of such particles with organic compounds to achieve hydrophobicity can be cited. Examples include organosilicon-based or silane-based treatments using methyl hydrogen-containing polysiloxanes, dimethyl polysiloxanes (polydimethylsiloxane), alkylsilanes, etc.; fluorine-based treatments using perfluoroalkyl phosphates, perfluoroalcohols, etc.; titanate-based treatments using alkyl titanates, etc.; amino acid treatments using N-acylglutamic acid, etc. Other examples include lecithin treatment; metal soap treatment; fatty acid treatment; and alkyl phosphate treatment. Hydrophobication treatments can be used alone or in combination. Furthermore, hydrophobication treatment can be carried out using hydrophobicating agents.

[0057] Examples of organosilicones used as hydrophobic treatment agents include, for instance, known organosilicones having hydrogen-silicon bonds, such as methyl hydrogen-containing polysiloxane (polydimethylsiloxane / polymethylsiloxane) copolymers. Other examples include triethoxysilyl ethyl polydimethylsiloxane and triethoxysilyl ethyl polydimethylsiloxane, which have alkoxy-silicon bonds as reactive groups. Dimethyl polysiloxanes may also be used.

[0058] Examples of silane-based processing agents include, for example, silylating agents with introduced organic groups, and silane coupling agents, for example, triethoxyoctylsilane.

[0059] Examples of titanium coupling agents that can be used as titanate-based treatment agents include alkyl titanates, pyrophosphate-type titanates, phosphorous acid-type titanates, and amino acid-type titanates.

[0060] The type of particles constituting the pigment-grade hydrophobized treated particles is not particularly limited, and may be appropriately selected so as to obtain desired effects corresponding to the intended use (for example, water resistance, brightening effect, SPF). Examples of the pigment-grade hydrophobized treated particles include inorganic particles, specifically, inorganic oxide particles such as white inorganic oxide particles including titanium oxide particles, zinc oxide particles, cerium oxide particles and the like (sometimes referred to as "inorganic white pigment"). In addition, in general, inorganic particles and the like classified as pearlescent agents (bright pigments) or colorants can also be used as the pigment-grade hydrophobized treated particles of the present disclosure. As the pigment-grade hydrophobized treated particles of the present disclosure, organic particles can also be used. The pigment-grade hydrophobized treated particles may be used alone or in combination of two or more kinds.

[0061] The term "pearlescent agent" as used in the present disclosure refers to particles that do not contain a colorant and exhibit luster. Pearlescent agents typically have a flat plate-like form such as a lamellar or scaly shape. In addition, the term "colorant" as used in the present disclosure refers to a material that exhibits a color other than white, does not contain a pearlescent agent, and can impart color to a cosmetic composition without exhibiting luster. For example, from the viewpoint of the brightening effect, when a pearlescent agent is used, it is preferably used in combination with the above-mentioned inorganic oxide particles such as titanium oxide particles, and when a colorant is used, it is preferable to use the above-mentioned inorganic oxide particles such as titanium oxide particles and / or a pearlescent agent in combination.

[0062] Examples of the pearlescent agent include titanium mica, iron oxide-coated titanium mica, carmine-coated titanium mica, carmine / ultramarine blue-coated titanium mica, iron oxide / carmine-treated titanium mica, ultramarine blue-treated titanium mica, iron oxide / ultramarine blue-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-titanium oxide coated mica such as red iron oxide-titanium oxide coated mica obtained by coating mica with iron oxide and titanium oxide, and hollow titanium oxide powder with silica interposed between mica and a titanium oxide coating layer. They typically exhibit white or other colors.

[0063] As the pearlescent agent, a colorless pearlescent agent can also be used. As such a pearlescent agent, a known substance known as a transparent pearlescent agent (transparent bright pigment) can be used. Examples thereof include a pearlescent agent obtained by using glass particles as a base material and forming a coating film made of a high refractive index material such as titanium oxide on the surface thereof.

[0064] As the colorant, for example, an inorganic pigment can be used.

[0065] Examples of inorganic pigments include: inorganic red pigments (e.g., iron oxide (iron oxide red), iron titanate, etc.); inorganic brown pigments (e.g., γ-iron oxide, etc.); inorganic yellow pigments (e.g., iron oxide yellow, loess, etc.); inorganic black pigments (e.g., iron oxide black, low-valent titanium dioxide, 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, navy blue, etc.); and metallic powders (e.g., aluminum, gold, silver, copper, etc.).

[0066] (First polyether-modified organosilicon)

[0067] The first polyether-modified organosilicon can function as a dispersant for pigment-grade hydrophobic treated particles. The first polyether-modified organosilicon can be used alone or in combination of two or more.

[0068] The first polyether-modified silicone has an HLB value greater than 10.0 and less than 18.0, exhibiting hydrophilic properties compared to the second polyether-modified silicone described later. From the viewpoint of the uniformity (sometimes simply referred to as "film uniformity") of the film containing pigment-grade hydrophobic treated particles and oil on the skin after contact with water, 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 preferably less than 17.5, 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 the value of 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 later can be easily determined using the Griffin method. Here, the HLB value obtained by the Griffin method can be calculated using the following equation 2: HLB value = 20 × total formula weight of hydrophilic portion / molecular weight... Equation 2 The amount of the first polyether-modified silicone, from the viewpoint of the dispersibility of the pigment-grade hydrophobic treated particles in the aqueous phase and the uniformity of the film, can be 0.01% by mass or more, 0.03% by mass or more, or 0.05% by mass or more relative to the total amount of cosmetics. Alternatively, it can be 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.

[0069] From the perspective of the dispersibility of pigment-grade hydrophobic treated particles in the aqueous phase, the uniformity of the film, and the UV protection effect, the mass ratio of pigment-grade hydrophobic treated particles to the first polyether modified organosilicon is preferably 10 or more, 12 or more, 14 or more, 15 or more, or 17 or more. In addition, it is 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.

[0070] As for the type of first polyether-modified organosilicon, there are no particular limitations as long as it has a specific HLB content. Examples include PEG-10 methyl ether polydimethylsiloxane, PEG-11 methyl ether polydimethylsiloxane, PEG / PPG-20 / 20 polydimethylsiloxane, PEG / PPG-20 / 23 polydimethylsiloxane, and PEG-17 polydimethylsiloxane. Among these, PEG-11 methyl ether polydimethylsiloxane is preferred.

[0071] (lower alcohols)

[0072] The disclosed water-in-oil emulsified cosmetic contains a second polyether-modified silicone, described later, along with a lower alcohol. When such a cosmetic is applied to the skin, the lower alcohol in the cosmetic evaporates, and consequently, the cosmetic on the skin transitions from a water-in-oil form to an oil-in-water form (sometimes simply referred to as "phase inversion emulsification"), thus exhibiting excellent water resistance.

[0073] The amount of lower alcohols mixed in, from the viewpoint of phase inversion emulsification and the associated water resistance, can be 5.0% by mass or more, 8.0% by mass or more, or 10% by mass or more relative to the total amount of cosmetics. Alternatively, it can 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.

[0074] There are no particular limitations on the type of lower alcohol, but preferred examples are monohydric alcohols having an alkyl group having 1 to 5 carbon atoms, and more preferably monohydric alcohols having an alkyl group having 1 to 3 carbon atoms. Specifically, examples include ethanol, propanol, isopropanol, isobutanol, and tert-butanol, with ethanol being preferred. Lower alcohols can be used alone or in combination of two or more.

[0075] <Oil Drops>

[0076] The oil droplets in the oil phase or dispersed phase of the water-in-oil emulsion cosmetic contain oil and a second polyether-modified silicone with an HLB of 10.0 or less.

[0077] (oil content)

[0078] There are no particular limitations on the oil content in the water-in-oil emulsion cosmetic disclosed herein. For example, from the viewpoint of water resistance and film uniformity, relative to the total amount of cosmetic, it 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. Alternatively, it can 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.

[0079] For example, cosmetics with a high oil content of 20% or more by mass can further improve the UV protection effect (SPF) by increasing the proportion of hydrophobic microparticles, such as UV absorbers and any of the ingredients described below, that can be blended into the oil phase.

[0080] There are no particular restrictions on the type of oil used; for example, volatile oils and non-volatile oils can be used. Oils can be used alone or in combination of two or more. Here, "volatility" refers to a volatile content exceeding 5% after being placed at 105°C for 3 hours under atmospheric pressure. From the viewpoint of film uniformity, the volatile content, 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, this boiling point is preferably 250°C or less, 240°C or less, or 230°C or less; furthermore, it is preferably 80°C or more, 100°C or more, 120°C or more, 150°C or more, or 160°C or more. Furthermore, the term "non-volatile" in this disclosure means that the volatile components are less than 5% after being placed at 105°C for 3 hours.

[0081] There are no particular limitations on volatile oils; examples include volatile silicone oils and volatile hydrocarbon oils. Volatile oils can be used alone or in combination of two or more.

[0082] Examples of volatile silicone oils include volatile acyclic silicone oils and volatile cyclic silicone oils. Among these, volatile acyclic silicone oils are preferred.

[0083] As volatile acyclic silicone oils, for example, volatile linear silicone oils and volatile branched silicone oils can be used. Among them, volatile linear silicone oils are preferred.

[0084] Examples of volatile linear silicone oils include, for instance, low molecular weight linear dimethyl polysiloxanes such as dimethyl polysiloxane with a viscosity of 0.65 cSt (sometimes called "polydimethylsiloxane"), dimethyl polysiloxane with a viscosity of 1 cSt, dimethyl polysiloxane with a viscosity of 1.5 cSt, and dimethyl polysiloxane with a viscosity of 2 cSt. Among these, dimethyl polysiloxane with a viscosity of 1 cSt and dimethyl polysiloxane with a viscosity of 1.5 cSt are preferred from the viewpoint of film uniformity. Here, their viscosity refers to the kinematic viscosity at 25°C.

[0085] Examples of volatile branched silicone oils include, for example, low molecular weight branched siloxanes such as methyl polytrimethylsiloxane, tris(trimethylsilyl)methylsilane, and tetra(trimethylsilyl)silane.

[0086] Examples of volatile cyclic silicone oils include, for example, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecylcyclohexasiloxane.

[0087] Examples of volatile hydrocarbon oils include heptane, isododecane, isohexadecane, and isodecane. Among these, isododecane is preferred from the viewpoint of film uniformity.

[0088] The amount of volatile oil in the oil fraction, relative to the total oil fraction, can be 0% or more by mass, 5% or more by mass, 10% or more by mass, 15% or more by mass, 20% or more by mass, 25% or more by mass, 30% or more by mass, 35% or more by mass, 40% or more by mass, or 45% or more by mass. Alternatively, it can be 90% or less by mass, 85% or less by mass, 75% or less by mass, 65% or less by mass, 60% or less by mass, 55% or less by mass, or 50% or less by mass. In this case, the remaining portion of the oil fraction can be non-volatile oil.

[0089] Besides the volatile oils mentioned above, other oils commonly used in cosmetics include liquid oils, solid oils, waxes, hydrocarbon oils (other than those mentioned), silicone oils (other than those mentioned), and polar oils. If other oils (e.g., non-volatile oils) are used in combination with volatile oils, these other oils can function as a binder between the particles and the skin after the volatile oils evaporate, thus allowing the particles to be properly immobilized on the skin. These other oils can be used alone or in combination of two or more. In ultraviolet absorbers, there are also substances that function as oils, particularly polar oils. Such ultraviolet absorbers can also be considered oils.

[0090] Examples of liquid oils include, for example, avocado oil, camellia oil, turtle oil, macadamia nut oil, corn oil, mink oil, olive oil, rapeseed oil, egg yolk oil, sesame oil, peach kernel oil, wheat germ oil, camellia oil, castor oil, flaxseed oil, safflower oil, cottonseed oil, perilla oil, soybean oil, peanut oil, tea seed oil, torreya nut oil, rice bran oil, white tung oil, Japanese tung oil, jojoba oil, germ oil, and triglycerides.

[0091] Examples of solid fats include, for example, 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, wood wax kernel oil, hardened oil, beef foot fat, wood wax, and hardened castor oil.

[0092] Examples of waxes include, for example, beeswax, candelilla wax, cotton wax, carnauba wax, laurel wax, insect wax, whale wax, lignite wax, rice bran wax, lanolin, kapok wax, acetylated lanolin, liquid lanolin, sugarcane wax, lanolin fatty acid isopropyl ester, 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.

[0093] Examples of hydrocarbon oils include, for example, liquid paraffin, ceresin, squalane, pterostilbene, paraffin, pure ceresin, squalene, petrolatum, microcrystalline wax, and olefin oligomers.

[0094] Examples of silicone oils include chain organosilicones such as dimethylpolysiloxane (polydimethylsiloxane), methylphenylpolysiloxane (diphenylsiloxyphenylpolytrimethylsiloxane), and methyl hydrogen-containing polysiloxane with a viscosity of 6 cSt or higher.

[0095] As a polar oil, for example, a polar oil with an IOB value of 0.10 or higher 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 isotriadecane isononanoate. Cetyl ester (IOB value = 0.15), cetyl ester of ethylhexanoate (IOB value = 0.13), pentaerythritol 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 didecanoate (IOB value = 0.25), diisostearate malate (IOB value = 0.15). IOB value = 0.28), trimethylolpropane triisostearate (IOB value = 0.16), tri-2-ethylhexanoate (triisooctanoate) (IOB value = 0.35), trimethylolpropane trioctanoate (IOB value = 0.33), trimethylolpropane triisostearate (IOB value = 0.16), diisobutyl adipic acid (IOB value = 0.46), N-lauroyl-L-glutamic acid-2-octyldodecyl ester (IOB value = 0.29), 2-hexyl adipic acid Decyl ester (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), triisostearate (IOB value = 0.16), dineovaleric acid PPG-3 (IOB value = 0.52), and tri(caprylic / capric)glyceride (IOB value = 0.33).

[0096] Examples of UV absorbers that can be considered as oil-based include those with an IOB of 0.10 or higher. Specifically, these include organic UV absorbers such as ethylhexyl methoxycinnamate, octocrylene, polysiloxane-15, tert-butylmethoxydibenzoylmethane, ethylhexyl triazine, diethylhexyloxyphenol methoxyphenyl triazine, diethylaminohydroxybenzoyl benzoate, hydroxybenzophenone-3, methylenebisbenzotriazolyltetramethylbutylphenol, homosalate, and ethylhexyl salicylate. These UV absorbers can be used alone or in combination of two or more.

[0097] The IOB values ​​of polar oils and ultraviolet absorbers can be, for example, 0.11 or higher, 0.12 or higher, or 0.13 or higher; and can also be 0.50 or lower, 0.45 or lower, or 0.40 or lower. Here, IOB value is short for Inorganic / Organic Balance, and it represents the ratio of inorganic value to organic value, serving as an indicator of the degree of polarity of the organic compound. Specifically, the IOB value is expressed as IOB value = inorganic value / organic value. Regarding the "inorganic value" and "organic value" respectively, for example, the "organic value" is 20 for one carbon atom in the molecule and the "inorganic value" is 100 for one hydroxyl group. The "inorganic value" and "organic value" corresponding to various atoms or functional groups are set. By accumulating the "inorganic value" and "organic value" of all atoms and functional groups in the organic compound, the IOB value of the organic compound can be calculated (for example, see Yoshio Koda, "Organic Concept Map - Basics and Applications -", ​​pp. 11-17, Sankyo Publishing, 1984).

[0098] (Second polyether-modified organosilicon)

[0099] 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.

[0100] The second polyether-modified silicone has an HLB of 10.0 or less and exhibits oleophilic properties compared to 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 are no particular limitations on such lower limits of HLB; for example, it can be 1.0 or more, 1.5 or more, or 2.0 or more.

[0101] The amount of the second polyether-modified silicone, from the viewpoint of phase inversion emulsification and the associated water resistance, can be 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 relative to the total amount of cosmetics. Alternatively, it can be 10% by mass or less, 8.0% by mass or less, or 5.0% by mass or less.

[0102] Examples of second polyether-modified organosilicones include, for instance, polyether-modified organosilicones with a weight-average molecular weight of 50,000 or more that contain at least one selected from polyethylene oxide (POE) and polypropylene oxide (POP).

[0103] The weight-average molecular weight of polyether-modified organosilicon can be 50,000 or more, 55,000 or more, 60,000 or more, 65,000 or more, or 70,000 or more. Alternatively, it can 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 converted from polystyrene in gel permeation chromatography.

[0104] Examples of such polyether-modified organosilicones include, for instance, the polyether-modified organosilicon shown in Formula 1 below:

[0105] In Formula 1, m is an integer from 50 to 1,000, and the value range of m can be selected from integers above 50, above 70, above 100, above 120, above 150, or above 200, below 1,000, below 800, below 500, or below 300.

[0106] In Formula 1, n is an integer from 1 to 40, and the value range of n can be selected from integers above 1, above 3, above 5, above 7, or above 10, below 40, below 35, below 30, below 25, or below 20.

[0107] The ratio of m to n (m:n) is preferably 200:1 to 5:1, and particularly preferably 60:1 to 15:1.

[0108] In Formula 1, a is an integer from 5 to 50, and the numerical range of a can be selected from integers above 5, above 7, or above 10, below 50, below 45, below 40, below 35, below 30, below 25, or below 20.

[0109] In Formula 1, b is an integer from 5 to 50, and the value range of b can be selected from integers above 5, above 7, or above 10, below 50, below 45, below 40, below 35, below 30, below 25, or below 20.

[0110] The content of polyoxyalkylene groups in the molecule of Formula 1 is not particularly limited, but from the viewpoint of phase inversion emulsification, it is preferably 20% or more by mass, more than 20% by mass, or 25% or more by mass, preferably 50% or less by mass, 40% or less by mass, 35% or less by mass, or 30% or less by mass in the total molecular weight.

[0111] As a second polyether-modified organosilicon, examples include, for instance, PEG / PPG-19 / 19 polydimethylsiloxane, PEG / PPG-20 / 22 butyl ether polydimethylsiloxane, PEG / PPG-20 / 20 polydimethylsiloxane, and PEG / PPG-30 / 10 polydimethylsiloxane.

[0112] <Any component>

[0113] The water-in-oil emulsion cosmetic disclosed herein can be appropriately blended with various ingredients to a extent that does not affect the effects of this disclosure. Examples of such ingredients include additives commonly 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 organosilicon polysaccharides, higher fatty acids such as isostearic acid, metal ion blocking agents, higher alcohols such as stearyl alcohol, polyols, various extracts, sugars, amino acids, organic amines, polymeric emulsions, chelating agents, other ultraviolet absorbers besides the aforementioned ultraviolet absorbers, pH adjusters, skin nutrients, vitamins, pharmaceuticals, quasi-pharmaceuticals, water-soluble agents applicable in cosmetics, buffers, fading inhibitors, preservatives, dispersants, spraying agents, fillers, pigments other than those applicable in the aforementioned pearlescent agents and colorants (e.g., organic pigments), hydrophobically treated microparticles, dyes, pigments, fragrances, etc. Any component can be mixed in the oil phase and / or aqueous phase, and can be used alone or in combination of two or more. Several of the components are described below.

[0114] (Nonionic surfactant)

[0115] In several embodiments, the water-in-oil emulsion cosmetic of this disclosure comprises a nonionic surfactant.

[0116] Examples of nonionic surfactants include polyoxyalkylene ethers, polyalkylene glycol fatty acid esters, POE-cured castor oil derivatives, POE alkyl ethers, POE / POP alkyl ethers, PEG fatty acid esters, polyglycerol fatty acid esters, POE glycerol fatty acid esters, and PEG-glycerol isostearate. Additionally, nonionic surfactants such as diisostearate polyglycerol-2 and sesquiisostearate sorbitan ester can also be used. Two or more nonionic surfactants can be used alone or in combination.

[0117] Examples of polyoxyethylene alkyl ethers include, for example, polyoxyethylene benzyl ether and polyoxyethylene stearyl ether.

[0118] Examples of polyalkylene glycol fatty acid esters include, for example, polyethylene glycol monostearate and polyethylene glycol monooleate.

[0119] Examples of POE-hardened castor oil derivatives (PEG-hydrogenated castor oil) include, for example, POE(20-100)-hardened castor oil derivatives. Specifically, examples include POE(20)-hardened castor oil derivatives, POE(40)-hardened castor oil derivatives, POE(60)-hardened castor oil derivatives, and POE(100)-hardened castor oil derivatives.

[0120] Examples of POE alkyl ethers include, for example, 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, POE(15) oleyl ether, POE(20) oleyl ether, POE(50) oleyl ether, POE(10) styraxyl ether. 20-base ether, POE(20) basal ether, POE(30) mountain Alkyl 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.

[0121] Examples of POE / POP alkyl ethers include, for example, 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.

[0122] Examples of PEG fatty acid esters include, for example, polyethylene laurate (hereinafter abbreviated as PEG) (10), PEG (10) monostearate, PEG (25) monostearate, PEG (40) monostearate, PEG (45) monostearate, PEG (55) monostearate, PEG (100) monostearate, PEG (10) monooleate, PEG distearate, and PEG diisostearate.

[0123] Examples of polyglycerol fatty acid esters include, for example, monolaurate hexaglyceride, monomyristate hexaglyceride, monostearate hexaglyceride, monooleate hexaglyceride, monolaurate decaglyceride, monomyristate decaglyceride, monostearate decaglyceride, monoisostearate decaglyceride, monooleate decaglyceride, distearate decaglyceride, and diisostearate decaglyceride.

[0124] Examples of POE glycerol fatty acid esters include, for example, polyoxyethylene monostearate (POE)(5) glycerol, POE monostearate (15) glycerol, POE monooleate (5) glycerol, and POE monooleate (15) glycerol.

[0125] Examples of isostearic acid PEG glycerides include, for example, isostearic acid PEG(8) glycerides, isostearic acid PEG(10) glycerides, isostearic acid PEG(15) glycerides, isostearic acid PEG(20) glycerides, isostearic acid PEG(25) glycerides, isostearic acid PEG glycerides (30), isostearic acid PEG(40) glycerides, isostearic acid PEG(50) glycerides, and isostearic acid PEG(60) glycerides.

[0126] There are no particular restrictions on the content of nonionic surfactants. For example, relative to the total amount of cosmetics, it can be 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. In addition, it 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.

[0127] (Water-soluble thickener)

[0128] In several embodiments, the water-in-oil emulsion cosmetic of this disclosure includes a water-soluble thickener. Cosmetics containing a water-soluble thickener can further improve emulsion stability.

[0129] There are no particular limitations on water-soluble thickeners, as long as they are used in cosmetics. Examples include natural water-soluble thickeners, semi-synthetic water-soluble thickeners, synthetic water-soluble thickeners, and inorganic water-soluble thickeners.

[0130] Examples of natural water-soluble thickeners include, for example, gum arabic, tragacanth, galactomannan, guar gum, carob gum, ebony gum, carrageenan, pectin, agar, quince seeds (quince), seaweed extract (brown algae extract), starch (rice, corn, potato, wheat), glycyrrhizic acid, and other plant-based polymers; xanthate gum, dextran, succinyl dextran, pullulan, and other microbial-based polymers; and collagen, casein, albumin, gelatin, and other animal-based polymers.

[0131] Examples of semi-synthetic water-soluble thickeners include starch-based polymers such as carboxymethyl starch and methyl hydroxypropyl starch; cellulose-based polymers such as methyl cellulose, nitrocellulose, ethyl cellulose, methyl hydroxypropyl cellulose, hydroxyethyl cellulose, sodium cellulose sulfate, hydroxypropyl cellulose, sodium carboxymethyl cellulose (CMC), crystalline cellulose, and cellulose powder; and alginate-based polymers such as sodium alginate and propylene glycol alginate.

[0132] Examples of synthetic water-soluble thickeners include, for instance, vinyl polymers such as polyvinyl alcohol, polyvinyl methyl ether, polyvinylpyrrolidone, and carboxyvinyl polymers (carbomer); polyoxyethylene polymers such as polyethylene glycol (weight average molecular weight: 1,500, 4,000, 6,000); copolymers of polyoxyethylene and polyoxypropylene; acrylic polymers such as sodium polyacrylate, ethyl polyacrylate, polyacrylamide, and alkyl methacrylate copolymers; and polyethyleneimine and cationic polymers.

[0133] Examples of inorganic water-soluble thickeners include, for example, bentonite, AlMg silicate, raponite, lithium montmorillonite, and silica anhydride.

[0134] The amount of water-soluble thickener used in the formulation, from the viewpoint of emulsification stability, may be 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 cosmetics. Alternatively, it may be 3.0% by mass or less, 2.0% by mass or less, or 1.0% by mass or less.

[0135] (Polyols)

[0136] In several embodiments, the water-in-oil emulsion cosmetic of this disclosure comprises a polyol. The polyol can improve the transparency and stability of the water-in-oil emulsion cosmetic.

[0137] Examples of polyols include ethylene glycol, propylene glycol, 1,3-butanediol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polybutylene glycol, and glycerin for Dana explosives.

[0138] The amount of polyols used in the blend, for example, from the viewpoint of emulsification stability, can be 0.1% or more by mass, 0.5% or more by mass, 1.0% or more by mass, 2.0% or more by mass, or 3.0% or more by mass relative to the total amount of cosmetics. Alternatively, it can be 15% or less by mass, 10% or less by mass, or 7.0% or less by mass.

[0139] (Hydrophobic treated microparticles)

[0140] In several embodiments, the water-in-oil emulsion cosmetic of this disclosure includes hydrophobically treated microparticles. From the viewpoints of UV protection and emulsion stability, the hydrophobically treated microparticles are preferably blended into the inner oil phase. Here, the aforementioned pigment-grade hydrophobically treated particles and hydrophobically treated microparticles can be distinguished by their size. That is, pigment-grade hydrophobically treated particles refer to hydrophobically treated particles with a larger particle size compared to hydrophobically treated microparticles.

[0141] There are no particular restrictions on the mixing amount of hydrophobic microparticles. They can be appropriately selected based on the desired effect corresponding to the application (e.g., UV scattering effect). For example, relative to the total amount of cosmetics, it 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. Alternatively, it can 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.

[0142] For example, hydrophobic treated microparticles with an average particle size of less than 200 nm can improve performance such as ultraviolet scattering. The average particle size of the hydrophobic treated microparticles can be appropriately selected based on the desired effect (e.g., ultraviolet scattering effect) corresponding to the application; for example, it can be less than 200 nm, less than 180 nm, less than 150 nm, less than 120 nm, less than 100 nm, or less than 80 nm. There is no particular limitation on the lower limit of the average particle size of the hydrophobic treated microparticles; for example, it can be greater than 10 nm, greater than 20 nm, greater than 30 nm, greater than 40 nm, greater than 50 nm, greater than 60 nm, or greater than 70 nm.

[0143] There are no particular limitations on the hydrophobic treatment of the hydrophobic particles. For example, the same treatment as that performed on the pigment-grade hydrophobic particles described above can be carried out.

[0144] There are no particular restrictions on the types of particles constituting the hydrophobic treatment microparticles. They can be appropriately selected based on the desired effect corresponding to the application (e.g., ultraviolet scattering effect). Examples include inorganic particles, specifically titanium oxide, zinc oxide, barium sulfate, iron oxide, talc, mica, sericite, kaolin, mica titanium, dark blue, chromium oxide, chromium hydroxide, silicon dioxide, and cerium oxide. The hydrophobic treatment microparticles can be used alone or in combination of two or more. When using hydrophobic treatment microparticles as ultraviolet scattering agents, particles with a refractive index of 1.5 or higher, such as zinc oxide particles and titanium oxide particles, are preferred from an optical property point of view.

[0145] <Vitality of Cosmetics>

[0146] In several embodiments, the viscosity of the water-in-oil emulsion cosmetic material of this disclosure, measured under the conditions and apparatus described in the following examples, 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 immediately after the cosmetic material is made; or it 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 a viscosity of the cosmetic material immediately after its manufacture can be referred to as its "initial viscosity".

[0147] <Cumulative absorbance fraction after water resistance test>

[0148] In several embodiments, the cumulative absorbance fraction after a water resistance test, measured under the conditions and apparatus described in the following examples regarding the use of the water-in-oil emulsion cosmetic of this disclosure, can be 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 limitation on the upper limit of such a cumulative absorbance fraction; for example, it can be 130% or less, 125% or less, or 120% or less.

[0149] When cosmetics are applied to the skin, the uniformity of the film formed after contact with water can be indirectly determined by the cumulative absorbance fraction after a water resistance test. This cumulative absorbance fraction is the ratio of the cumulative absorbance of the test sample after the water resistance test (prepared by spreading the cosmetics onto a specified substrate and allowing it to dry) to the cumulative absorbance before the water resistance test. In other words, an increase in this cumulative absorbance fraction indicates that the pigment-grade hydrophobic treated particles are more evenly distributed on the skin after the water resistance test.

[0150] Preparation Method of Water-in-Oil Emulsion Cosmetics

[0151] There are no particular limitations on the preparation method of the water-in-oil emulsion cosmetic disclosed herein. For example, it can be prepared by known methods such as dispersion or agglomeration.

[0152] The so-called dispersion method is a method of refining a dispersed phase mass through mechanical force. Specifically, it is a method of emulsification using the crushing force of an emulsifier. For example, high-pressure emulsification using a high-pressure homogenizer with added high shear force can be cited as such a method.

[0153] The so-called agglomeration method is a colloidal modulation method that utilizes the surface chemical properties. It involves creating a supersaturated state from a homogeneously miscible state, thus forming a dispersed phase. Specific methods include HLB temperature emulsification, phase inversion emulsification, non-aqueous emulsification, D-phase emulsification, and liquid crystal emulsification.

[0154] Formulations of Water-in-Oil Emulsion Cosmetics

[0155] There are no particular limitations on the dosage form of the water-in-oil emulsion cosmetic disclosed herein, and examples include liquid, emulsion, cream, gel, spray, and mousse. Here, the term "spray" in this disclosure may include mist spray, aerosol spray, etc.

[0156] Applications of water-in-oil emulsion cosmetics

[0157] The water-in-oil emulsion cosmetic disclosed herein can uniformly apply pigment-grade hydrophobic treated particles to the surface of the skin, exhibiting good water resistance and brightening effects. Therefore, the cosmetic of this disclosure, capable of such properties, can be used, for example, as a cosmetic that is spread and applied to the skin. Since the water resistance and brightening properties of the cosmetic of this disclosure are further enhanced upon contact with water (e.g., sweat), it is preferably used, for example, as a cosmetic that is applied to the skin after water, or as a cosmetic that can come into contact with water (e.g., sweat, saliva, rainwater, seawater, swimming pool water). Here, the cosmetic applied to the skin may also contain substances referred to as topical skin agents.

[0158] The product form of the cosmetics disclosed herein is not particularly limited, and examples include, for instance, facial cosmetics such as lotions, serums, lotions, and masks; color cosmetics such as foundations, lipsticks, and eyeshadows; sunscreen cosmetics (sunscreen agents); body cosmetics; hair cosmetics such as shampoos, hair oils, conditioners, perfumes, hair conditioners, and hair growth products; and ointments. The cosmetics disclosed herein can be suitable for use as sunscreen cosmetics (sunscreen agents) that may come into contact with water after being applied to the skin, such as in a swimming pool or the sea, or as facial cosmetics, color cosmetics, or body cosmetics that may adhere to moisture such as sweat or saliva.

[0159] Example

[0160] The following examples illustrate the water-in-oil emulsion cosmetics of this disclosure in further detail, but the cosmetics of this disclosure are not limited to these examples. Furthermore, unless otherwise specified, the mixing amount will be expressed as a percentage by mass (%).

[0161] Examples 1-6 and Comparative Examples 1-6

[0162] The water-in-oil emulsion cosmetics obtained by the formulations shown in Table 1 and the manufacturing methods described below were evaluated, and the results are shown in Table 1. Here, "O / W (aqueous phase)" in the table refers to a water-in-oil emulsion cosmetic in which pigment-grade hydrophobic treated particles are contained in the aqueous phase, "O / W" refers to a water-in-oil emulsion cosmetic in which no particles are contained, and "O / W (oil phase)" refers to a water-in-oil emulsion cosmetic in which pigment-grade hydrophobic treated particles are contained in the oil phase.

[0163] Evaluation Methods

[0164] (Highlighted review)

[0165] The prepared cosmetic material was applied to the wrist and allowed to dry. The application surface was then visually observed, and the brightening effect was evaluated according to the following criteria. Here, an A rating is considered acceptable, while ratings B through C are considered unacceptable. Furthermore, this brightening test, in addition to the brightening effect, can indirectly evaluate whether the pigment-grade hydrophobic treated particles are evenly applied to the skin surface. That is, it can be said that, in the order of C, B, and A, the pigment-grade hydrophobic treated particles are evenly applied to the skin surface.

[0166] A: The brightness is even, demonstrating an excellent brightening effect.

[0167] B: The brightness is slightly uneven, and the brightening effect is not good.

[0168] C: The brightness is noticeably uneven, and a good brightening effect cannot be achieved.

[0169] (Cumulative absorbance fraction after water resistance test)

[0170] On a measuring plate (S plate) (5×5cm V-groove PMMA plate, SPF MASTER PA01, manufactured by Shiseido Co., Ltd.), the prepared cosmetic was applied at a concentration of 2mg / cm³. 2The sample was added dropwise and spread with a finger for 60 seconds. After drying for 15 minutes, the absorbance in the wavelength range of 280–400 nm was measured using a Hitachi U-3500 self-recording spectrophotometer. Using glycerol, which has no UV absorption, as a control, the absorbance was calculated using Equation 3. Here, T in Equation 3 refers to the transmittance of the sample, and T0 refers to the transmittance of glycerol. Absorbance = -log(T / T0) …Equation 3 The tested plates were thoroughly immersed in water with a hardness of 50-500 for 30 minutes, and stirred at 300 rpm using a slurry mixer. Then, they were dried for approximately 15-30 minutes until the surface water droplets disappeared, and the absorbance was measured again. The cumulative absorbance fraction (sometimes called "absorbance change rate") was calculated from the cumulative absorbance before and after the water bath using Equation 4. Here, if the cumulative absorbance fraction is 100% or higher, the plate exhibits performance equal to or better than before the water resistance test, and therefore, it can be said to have excellent water resistance. Cumulative absorbance fraction (%) = Cumulative absorbance after water bath × 100 / Cumulative absorbance before water bath... Equation 4 (Enhanced: UV protection effect) The cumulative absorbance fraction after the above water resistance test is the measurement result within the range of 280-400 nm, corresponding to the UVA-UVB range. Based on this measurement result, the improvement (enhancement) of the UV protection effect was evaluated according to the following criteria. Here, A-C ratings are considered acceptable, and D rating is considered unacceptable. Furthermore, in addition to the UV protection effect, the improvement result can also indirectly evaluate whether the pigment-grade hydrophobic treated particles are uniformly applied to the skin surface. That is, it can be said that, in the order of D, C, B, A, the pigment-grade hydrophobic treated particles are uniformly applied to the skin surface.

[0171] A: The cumulative absorbance fraction is over 110%.

[0172] B: The cumulative absorbance fraction is 105% or higher and less than 110%.

[0173] C: The cumulative absorbance fraction is 100% or more but less than 105%.

[0174] D: Cumulative absorbance fraction is less than 100%.

[0175] (Evaluation of particle dispersion)

[0176] The prepared cosmetic material was added to a 50 mL transparent sample tube (3 cm in diameter), and the dispersion of the pigment-grade hydrophobic treated particles after being stored at 25 °C for 7 days was observed visually. The evaluation was carried out according to the following criteria.

[0177] A: No precipitates of pigment-grade hydrophobic treated particles were identified.

[0178] B: The precipitate of pigment-grade hydrophobic treated particles was confirmed very slightly.

[0179] C: The precipitate of pigment-grade hydrophobic treated particles was slightly confirmed.

[0180] D: The precipitate of pigment-grade hydrophobic treated particles was clearly confirmed.

[0181] (Rotational stability evaluation)

[0182] The prepared cosmetic material was added to a 50 mL transparent sample tube (3 cm in diameter). The sample tube was rotated at 45 rpm for 4 hours under an atmosphere of 25 °C. The aggregation state of the pigment-grade hydrophobic treated particles was observed visually and evaluated according to the following criteria.

[0183] A: No color streaks were observed in the aggregates of pigment-grade hydrophobic particles.

[0184] B: The color stripe pattern of the aggregates accompanying the pigment-grade hydrophobic treatment particles was observed very slightly.

[0185] C: A slight color stripe pattern was observed in the aggregates of pigment-grade hydrophobic treated particles.

[0186] D: The color stripes of the aggregates accompanying the pigment-grade hydrophobic treatment particles were clearly observed.

[0187] (Viscosity evaluation)

[0188] The viscosity of the cosmetic material freshly made was evaluated using a type B viscometer (TVB-10, manufactured by Toki Sangyo Co., Ltd.) under the conditions of rotor number 4, 30°C, and 12 rpm.

[0189] <Methods for Manufacturing Cosmetics>

[0190] Using the formula shown in Table 1, an oil-in-water emulsion cosmetic was manufactured by the following method. Here, the numbers shown below correspond to the numbers to the left of the ingredient names displayed in the formula of Table 1.

[0191] (Example 1)

[0192] The aqueous phase fraction was obtained by uniformly mixing materials No.2 to No.12 with a portion of the ion-exchanged water No.1.

[0193] The oil phase was obtained by uniformly mixing materials No. 20 to No. 25.

[0194] In the remaining ion-exchanged water of No.1, the materials of No.13, No.16 and No.17 were uniformly mixed to obtain the powder portion.

[0195] After the oil phase was slowly added to the aqueous phase, the powder phase was slowly added and uniformly dispersed using a homogenizer to obtain the oil-in-water emulsion cosmetic of Example 1.

[0196] (Examples 2-5 and Comparative Examples 2-5)

[0197] The formulations were changed to those shown in Table 1, and the same procedures were followed as in Example 1 to obtain the oil-in-water emulsion cosmetics of Examples 2-5 and Comparative Examples 2-5.

[0198] (Comparative Example 1)

[0199] The formulation was changed to that shown in Table 1, and the powder portion was not used. Otherwise, the same procedure as in Example 1 was followed to obtain the water-in-oil emulsion cosmetic of Comparative Example 1.

[0200] (Comparative Example 6)

[0201] In the ion-exchanged water No.1, materials No.2 to No.12 were added and mixed evenly to obtain the aqueous phase.

[0202] The oil phase was obtained by uniformly mixing materials No. 20 to No. 26.

[0203] Material No. 27 was slowly added to the oil phase to prepare a mixture. Then, the mixture was slowly added to the aqueous phase and homogenized using a homogenizer to obtain the oil-in-water emulsion cosmetic of Comparative Example 6.

[0204]

[0205] <result>

[0206] Based on the results in Table 1, the water-in-oil emulsion cosmetics of Examples 1-5 of this disclosure, which contain pigment-grade hydrophobic treated particles in the aqueous phase, were found to have excellent brightening and water resistance properties.

[0207] Furthermore, the cumulative absorbance fractions after the water resistance test of the cosmetic product (Comparative Example 1) without pigment-grade hydrophobic treated particles and the cosmetic product containing pigment-grade hydrophobic treated particles in the oil phase were 97% and 99%, respectively, which are relatively good results regarding water resistance. This can be attributed to the fact that these cosmetic products also use lower alcohols and second polyether-modified silicones, which contribute to the phase inversion emulsification performance of water resistance after application to the skin. Therefore, if lower alcohols are not used, or if other emulsifiers that do not perform phase inversion emulsification are used instead of second polyether-modified silicones, the water resistance is expected to deteriorate.

[0208] If we observe the cumulative absorbance fraction after the water resistance test in Comparative Examples 1, 5, and 6, we find that when pigment-grade hydrophobic particles are not used, or pigment-grade particles without hydrophobic treatment are mixed in the aqueous phase, or pigment-grade hydrophobic particles are mixed in the oil phase, no improvement in performance is observed even when water is applied to the cosmetic; that is, no increase in UV protection effect is observed. On the other hand, in the case of the water-in-oil emulsion cosmetics of Examples 1-5, an improvement in performance can be observed when water is applied to the cosmetic.

[0209] Furthermore, it is known that the water-in-oil emulsion cosmetics of Examples 1-5 also exhibit excellent rotational stability and particle dispersibility.

[0210] Explanation of symbols

[0211] 10 First polyether-modified organosilicon

[0212] 20 Pigment-grade hydrophobic treated particles

[0213] 30 water

[0214] 40 oil content.

Claims

1. A water-in-oil emulsion cosmetic, comprising: Dispersion media containing water, and Oil droplets dispersed in the dispersion medium, The dispersion medium comprises a first polyether-modified silicone with an HLB value of 12.0 or higher and 15.0 or lower, a lower alcohol, and pigment-grade hydrophobic treated particles with an average particle size of 250 nm or higher. The oil droplets contain oil and a second polyether-modified silicone with an HLB value of less than 5.

0. The content of the first polyether-modified organosilicon is more than 0.01% by mass and less than 1.0% by mass relative to the total amount of cosmetics. The content of the second polyether-modified silicone is more than 0.1% by mass and less than 5.0% by mass relative to the total amount of cosmetics. The mass ratio of the pigment-grade hydrophobic treated particles to the first polyether-modified organosilicon is 10 or more and 70 or less, and The value of HLB is calculated using the following formula: HLB value = 20 × total formula weight of hydrophilic part / molecular weight.

2. The cosmetic according to claim 1, wherein the first polyether-modified organosilicon is PEG-11 methyl ether polydimethylsiloxane, and the second polyether-modified organosilicon is PEG / PPG-19 / 19 polydimethylsiloxane.

3. The cosmetic material according to claim 1 or 2, wherein the lower alcohol comprises 5.0% by mass or more relative to the total amount of the cosmetic material.

4. The cosmetic according to claim 1 or 2, wherein the dispersion medium further comprises a water-soluble thickener.

5. The cosmetic according to claim 1 or 2, wherein the mass ratio of the pigment-grade hydrophobic treated particles to the first polyether-modified organosilicon is 12 or more and 70 or less.

6. The cosmetic material according to claim 1 or 2, wherein the cumulative absorbance fraction after the water resistance test is more than 100% compared with that before the water resistance test.

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