Oil-in-water type emulsified cosmetic

Abstract

To provide oil in water type emulsified cosmetics that have excellent emulsion stability and can give a feeling of collapse as a feeling of use, which contain an acid-type or salt-type whitening agent or an anti-inflammatory agent.SOLUTION: The oil-in-water type emulsified cosmetic of the present disclosure contains: a dispersion medium containing at least one selected from a whitening agent and anti-inflammatory agent, and water; and an oil droplet dispersed in this dispersion medium, the oil droplet containing an oil, a linear higher fatty acid having 16 or more carbon atoms, a monohydric higher alcohol, and a nonionic surfactant, the whitening agent containing at least one selected from a salt-type whitening agent and an acid-type whitening agent, the anti-inflammatory agent containing at least one selected from a salt-type anti-inflammatory agent and an acid-type anti-inflammatory agent, the oil containing a volatile acyclic silicone oil, and in addition the viscosity ratio (V0.6rpm / V12rpm) of the viscosity (V0.6rpm) measured at 0.6 rpm with respect to the viscosity (V12rpm) measured at 12 rpm showing 7.9 or higher, when using a B-type viscometer in an atmosphere of 30°C.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to an oil-in-water type emulsified cosmetic.

Background Art

[0002] In recent years, oil-in-water type emulsified cosmetics having emulsion stability and various use feelings have been developed.

[0003] Patent Document 1 discloses an emulsified composition containing (a) 0.01 to 5% by weight of a polysiloxane-polyoxyalkylene copolymer, (b) 0.05 to 1% by weight of a nonionic surfactant, (c) 10 to 30% by weight of a humectant, and (d) 1 to 50% by weight of urea, which exhibits an excellent moisturizing effect while reducing the irritation of urea and has a very refreshing use feeling.

[0004] Patent Document 2 discloses an emulsified composition containing a poorly soluble drug, an oily component containing two or more higher alcohols, water, and a surfactant, wherein one of the higher alcohols is behenyl alcohol, and the emulsified composition has excellent usability and excellent dispersion stability and emulsion stability of the drug.

[0005] Patent Document 3 discloses an emulsified composition in which 0.05 to 50.0% by mass of a glycoside of urea and / or ascorbic acid is blended, and (A) 0.01 to 5.0% by mass of a polysiloxane-polyoxyalkylene copolymer and (B) 0.05 to 1.0% by mass of a nonionic surfactant or 0.05 to 5.0% by mass of a higher fatty acid having 12 or more carbon atoms are blended, and the emulsified composition has excellent stability and a non-sticky and refreshing use feeling.

[0006] It should be noted that Patent Documents 4 and 5 describe that when a whitening agent such as tranexamic acid is blended in an oil-in-water type emulsified cosmetic, the stability decreases as a background art.

Prior Art Documents

Patent Documents

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-247427 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-354548 [Patent Document 3] Japanese Patent Application Laid-Open No. 2002-249665 [Patent Document 4] Japanese Patent Application Laid-Open No. 2019-142825 [Patent Document 5] Japanese Patent Application Laid-Open No. 2018-123067 [Summary of the Invention] [Problems to be Solved by the Invention]

[0008] In the emulsion composition constituting the cosmetic, a whitening agent, an anti-inflammatory agent, etc. may be blended. Among them, the use of an acid-type or salt-type whitening agent or anti-inflammatory agent easily breaks the emulsion balance between the aqueous phase and the oil phase. Therefore, it has been difficult to improve the emulsion stability of an oil-in-water type emulsified cosmetic containing such an agent. Moreover, it has been even more difficult to adjust the feel of use of an oil-in-water type emulsified cosmetic containing such an agent.

[0009] Therefore, the subject of the present disclosure is to provide an oil-in-water type emulsified cosmetic containing an acid-type or salt-type whitening agent or anti-inflammatory agent, which has excellent emulsion stability and can exhibit a crumbling feeling as the feel of use. [Means for Solving the Problems]

[0010] <Aspect 1> An oil-in-water type emulsified cosmetic containing at least one selected from a whitening agent and an anti-inflammatory agent, a dispersion medium containing water, and oil droplets dispersed in the dispersion medium wherein the oil droplets contain an oil component, a linear higher fatty acid having 16 or more carbon atoms, a monohydric higher alcohol, and a nonionic surfactant, the whitening agent contains at least one selected from a salt-type whitening agent and an acid-type whitening agent, The anti-inflammatory agent contains at least one selected from a salt-type anti-inflammatory agent and an acid-type anti-inflammatory agent, The oil component contains a volatile acyclic silicone oil, When measured with a B-type viscometer in an atmosphere of 30 °C, the viscosity (V 0.6rpm ) measured at 0.6 rpm and the viscosity (V 12rpm ) measured at 12 rpm, the viscosity ratio (V 0.6rpm / V 12rpm ) is 7.9 or more. An oil-in-water emulsion cosmetic. <Aspect 2> The cosmetic according to Aspect 1, wherein the mass ratio of the linear higher fatty acid to the monohydric higher alcohol is 0.30 or more. <Aspect 3> The cosmetic according to Aspect 1 or 2, wherein the linear higher fatty acid, the higher alcohol, and the nonionic surfactant form an interfacial film of the oil droplets in an atmosphere of 25 °C. <Aspect 4> The cosmetic according to any one of Aspects 1 to 3, wherein the linear higher fatty acid is at least one selected from stearic acid and behenic acid, and the higher alcohol is at least one selected from cetyl alcohol, isostearyl alcohol, stearyl alcohol, and behenyl alcohol. <Aspect 5> The cosmetic according to any one of Aspects 1 to 4, wherein the volatile acyclic silicone oil is contained in the oil component at 15% by mass or more. <Aspect 6> The cosmetic according to any one of Aspects 1 to 5, wherein the salt-type whitening agent is at least one selected from ascorbate, tranexamate, glycyrrhizinate, nicotinate, kojic acid salt, ellagic acid salt, 1-piperidinepropionate, 3-O-ethyl-L-ascorbate, and alkoxysalicylate, and the acid-type whitening agent is at least one selected from ascorbic acid, tranexamic acid, glycyrrhizic acid, nicotinic acid, kojic acid, ellagic acid, 1-piperidinepropionic acid, 3-O-ethyl-L-ascorbic acid, and alkoxysalicylate. <Aspect 7> The cosmetic according to any one of Aspects 1 to 6, wherein the anti-inflammatory agent is at least one selected from magnesium L-ascorbyl phosphate, dipotassium glycyrrhizinate, and ammonium glycyrrhizinate. 〈Aspect 8〉 The cosmetic according to any one of Aspects 1 to 7, wherein at least one selected from the salt-type whitening agent, the acid-type whitening agent, the salt-type anti-inflammatory agent, and the acid-type anti-inflammatory agent is contained in an amount of 50% by mass or more based on the total amount of the whitening agent component and the anti-inflammatory agent component. 〈Aspect 9〉 The cosmetic according to any one of Aspects 1 to 8, further comprising a divalent higher alcohol. 〈Aspect 10〉 The cosmetic according to any one of Aspects 1 to 9, wherein the content of the thickener is 1% by mass or less.

Advantages of the Invention

[0011] According to the present disclosure, it is possible to provide an oil-in-water type emulsified cosmetic containing an acid-type or salt-type whitening agent or anti-inflammatory agent, which is excellent in emulsion stability and can exhibit a crumbling feeling in terms of usability.

Modes for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present disclosure will be described in detail. The present disclosure is not limited to the following embodiments and can be variously modified and implemented within the scope of the gist of the invention.

[0013] The oil-in-water type emulsified cosmetic (sometimes simply referred to as "cosmetic") of the present disclosure includes at least one selected from a whitening agent and an anti-inflammatory agent, a dispersion medium containing water, and oil droplets dispersed in this dispersion medium. These oil droplets include an oil component, a linear higher fatty acid having 16 or more carbon atoms, a monovalent higher alcohol, and a nonionic surfactant. The whitening agent includes at least one selected from a salt-type whitening agent and an acid-type whitening agent, and the anti-inflammatory agent includes at least one selected from a salt-type anti-inflammatory agent and an acid-type anti-inflammatory agent. In addition to including a volatile acyclic silicone oil, the oil component has a viscosity (V) measured at 0.6 rpm when using a B-type viscometer in an atmosphere of 30°C. 0.6rpm) and the viscosity (V) measured at 12 rpm 12rpm ) and the viscosity ratio (V 0.6rpm / V 12rpm ) exhibits 7.9 or more.

[0014] Although not limited by theory, it is considered that the mechanism by which such oil-in-water emulsified cosmetics have excellent emulsion stability and can achieve a certain viscosity ratio and a non-collapsing feeling is as follows.

[0015] When an acid-type or salt-type whitening agent or anti-inflammatory agent is formulated in an oil-in-water emulsified cosmetic, the emulsion balance is disrupted, and thus it is expected that the emulsion stability of the cosmetic will decrease. Therefore, even if various documents disclose an oil-in-water emulsion composition containing a linear higher fatty acid having 16 or more carbon atoms, a monohydric higher alcohol, and a nonionic surfactant, those skilled in the art would not normally consider formulating an acid-type or salt-type whitening agent or anti-inflammatory agent that can destabilize the emulsion with respect to such a composition.

[0016] However, the present inventors have surprisingly found that even when an acid-type or salt-type whitening agent or anti-inflammatory agent is formulated, emulsion particles (oil droplets) prepared using specific materials, namely, a volatile acyclic silicone oil, a linear higher fatty acid having 16 or more carbon atoms, a monohydric higher alcohol, and a nonionic surfactant, have excellent emulsion stability.

[0017] The expression of such emulsion stability is considered to be affected, for example, by the fact that a linear higher fatty acid having 16 or more carbon atoms, a monohydric higher alcohol, and a nonionic surfactant form an interfacial film such as a gel film or a liquid crystal film based on a relatively strong lamellar liquid crystal or the like compared to a micelle structure around the emulsion particles at normal temperature, for example, in an atmosphere of 25 °C or 30 °C.

[0018] Here, the water-in-oil type emulsified cosmetic of the present disclosure can be prepared, for example, by mixing the above-described interfacial film constituent components and the oil component while heating to about 70 to 90°C to prepare an oil-phase solution, and then mixing water, a whitening agent, and / or an anti-inflammatory agent while heating to about 70 to 90°C to prepare an aqueous-phase solution. After gradually adding the oil-phase solution to this aqueous-phase solution while stirring, it can be prepared by cooling to room temperature. And in this cooling stage, it is considered that the interfacial film constituent components dissolved in the oil phase are separated from the oil component and solidify near the interface between the oil phase and the aqueous phase to form an interfacial film.

[0019] The water-in-oil type emulsified cosmetic of the present disclosure uses a volatile acyclic silicone oil as the oil component. This silicone oil has, for example, a property of being less compatible with the above-described interfacial film constituent components compared to cyclic silicone oils such as cyclopentasiloxane. Therefore, when a volatile acyclic silicone oil is used as the oil component, the interfacial film constituent components are more likely to be separated from the oil component compared to the case where the cyclic silicone oil, which is more compatible, is used. As a result, it is considered that more interfacial film constituent components migrate near the interface between the oil phase and the aqueous phase, and thus a stronger interfacial film is formed.

[0020] Thus, since the interfacial film is firmly formed in the water-in-oil type emulsified cosmetic of the present disclosure, it is considered to have excellent emulsion stability even when an acid-type or salt-type whitening agent or anti-inflammatory agent that can destabilize the emulsion is blended. Also, the presence of such a strong interfacial film is considered to affect the crumbling feeling in the cosmetic of the present disclosure. That is, the emulsified particles having an interfacial film are considered to exhibit a crumbling feeling because, unlike particles having a micelle structure, when a load exceeding the limit value is applied, the interfacial film breaks all at once.

[0021] The definitions of the terms in the present disclosure are as follows.

[0022] In the present disclosure, the "crumbling feeling" refers to the feeling of use such that when a load is applied to the cosmetic, the viscosity of the cosmetic suddenly decreases. Specifically, in the present disclosure, the "crumbling feeling" means that at the stage when the cosmetic is placed on the skin or the like, the viscosity is high and the fluidity is low, but when the cosmetic is rubbed and applied on the skin or the like, the viscosity decreases and it becomes a state with high fluidity and a smooth feeling. This crumbling feeling is the viscosity (V 0.6rpm ) measured at 0.6 rpm and the viscosity (V 12rpm ) measured at 12 rpm when using a B-type viscometer (TVB viscometer TVB-10, manufactured by Toki Sangyo Co., Ltd., rotor number L3) in an atmosphere of 30 °C, and can be defined by the viscosity ratio (V 0.6rpm / V 12rpm ). It is intended that this viscosity ratio be 7.9 or more.

[0023] 《Oil-in-water type emulsified cosmetic》 The oil-in-water type emulsified cosmetic of the present disclosure is excellent in emulsion stability. Here, the emulsion stability can be, for example, a state of not separating for 4 weeks at 0 °C to 37 °C, preferably for 4 weeks at 50 °C, preferably a state where the size change of the emulsion particles (oil droplets) is small or non-existent.

[0024] In addition, the oil-in-water type emulsified cosmetic of the present disclosure can exhibit a crumbling feeling. Such a crumbling feeling can be defined by the viscosity ratio (V 0.6rpm / V 12rpm ) as described above. The viscosity ratio can be 7.9 or more, 8.0 or more, 8.1 or more, 8.3 or more, 8.5 or more, 8.7 or more, 9.0 or more, 9.5 or more, or 10.0 or more. There is no particular limitation on the upper limit value of the viscosity ratio, but it can be, for example, 30.0 or less, 25.0 or less, 20.0 or less, or 15.0 or less.

[0025] The viscosity ratio of the oil-in-water type emulsified cosmetic can be controlled, for example, by adjusting at least one of the following conditions (a) to (c): (a) The mass ratio of the linear higher fatty acid to the monohydric higher alcohol. (b) Oil components (e.g., volatile acyclic silicone oils and polar oils), linear higher fatty acids having 16 or more carbon atoms, monohydric higher alcohols, and types of nonionic surfactants, as well as combinations thereof. (c) The proportion of volatile acyclic silicone oil and / or polar oil in the oil component.

[0026] The viscosity (V 12rpm ) of the oil-in-water type emulsified cosmetic of the present disclosure measured at 12 rpm is not particularly limited and can be appropriately specified in consideration of the application performance, usability, etc. of the cosmetic. For example, the viscosity (V 12rpm ) when measured using a B-type viscometer (TVB viscometer TVB-10, manufactured by Toki Sangyo Co., Ltd., rotor number L3) in an atmosphere of 30°C can be 20,000 mPa·s or less, 18,000 mPa·s or less, 15,000 mPa·s or less, 12,000 mPa·s or less, 10,000 mPa·s or less, 8,000 mPa·s or less, 6,000 mPa·s or less, or 5,000 mPa·s or less, and can also be 2,000 mPa·s or more, 2,200 mPa·s or more, 2,500 mPa·s or more, 2,700 mPa·s or more, or 3,000 mPa·s or more.

[0027] 〈Dispersion medium〉 The oil-in-water type emulsified cosmetic of the present disclosure contains a dispersion medium, and this dispersion medium contains at least one whitening agent selected from a salt-type whitening agent and an acid-type whitening agent, and / or at least one anti-inflammatory agent selected from a salt-type anti-inflammatory agent and an acid-type anti-inflammatory agent, and water.

[0028] (Whitening agent) There is no particular limitation on the blending amounts of the salt-type whitening agent and the acid-type whitening agent. For example, each independently can be 0.01% by mass or more, 0.05% by mass or more, 0.1% by mass or more, 0.3% by mass or more, 0.5% by mass or more, 0.7% by mass or more, or 1.0% by mass or more with respect to the total amount of the cosmetic, and can also be 15.0% by mass or less, 10.0% by mass or less, 8.0% by mass or less, or 5.0% by mass or less.

[0029] Examples of salt-type whitening agents include ascorbate, tranexamate, glycyrrhizinate, nicotinate, kojic acid salt, ellagic acid salt, 1-piperidinepropionate, 3-O-ethyl-L-ascorbate, and alkoxysalicylate (e.g., 4-methoxysalicylate). Examples of salts of salt-type whitening agents include alkali metal salts such as sodium salt and potassium salt; alkaline earth metal salts such as calcium salt and magnesium salt; zinc salt; iron salt; ammonium salt; salts with basic amino acids such as arginine, lysine, histidine, and ornithine; and salts with amines such as monoethanolamine, diethanolamine, and triethanolamine. The salt-type whitening agents can be used alone or in combination of two or more.

[0030] There is no particular limitation on the acid-type whitening agents. For example, ascorbic acid (L-ascorbic acid), tranexamic acid, glycyrrhizic acid, nicotinic acid, kojic acid, ellagic acid, 1-piperidinepropionic acid, 3-O-ethyl-L-ascorbic acid, and alkoxysalicylate (e.g., 4-methoxysalicylate) can be mentioned. The acid-type whitening agents can be used alone or in combination of two or more.

[0031] (Anti-inflammatory agent) There is no particular limitation on the blending amounts of the salt-type anti-inflammatory agent and the acid-type anti-inflammatory agent. For example, each independently can be 0.01% by mass or more, 0.05% by mass or more, 0.1% by mass or more, 0.3% by mass or more, 0.5% by mass or more, 0.7% by mass or more, or 1.0% by mass or more with respect to the total amount of the cosmetic, and can also be 15.0% by mass or less, 10.0% by mass or less, 8.0% by mass or less, or 5.0% by mass or less.

[0032] Examples of the salt-type anti-inflammatory agent include magnesium L-ascorbyl phosphate, dipotassium glycyrrhizinate, and ammonium glycyrrhizinate. The salt-type anti-inflammatory agent can be used alone or in combination of two or more.

[0033] Here, in the present disclosure, regarding agents that exhibit both whitening and anti-inflammatory effects among the above-described whitening agents and anti-inflammatory agents, they are treated as whitening agents.

[0034] (Water) There is no particular limitation on the blending amount of water. For example, from the viewpoints of emulsion stability, crumbling feeling, etc., it can be 50% by mass or more, 60% by mass or more, 70% by mass or more, or 80% by mass or more with respect to the total amount of the cosmetic, and it can also be 95% by mass or less, 90% by mass or less, or 85% by mass or less.

[0035] There is no particular limitation on the water that can be used in the water-in-oil type emulsified cosmetic of the present disclosure. For example, water used in cosmetics, quasi-drugs, etc. can be used. Examples of such water include ion-exchanged water, distilled water, ultrapure water, and tap water.

[0036] 〈Oil droplets〉 The oil droplets as the oil phase or the dispersed phase in the water-in-oil type emulsified cosmetic contain an oil component, a linear higher fatty acid having 16 or more carbon atoms, a monohydric higher alcohol, and a nonionic surfactant. Among these components, the linear higher fatty acid having 16 or more carbon atoms, the monohydric higher alcohol, and the nonionic surfactant can form the interfacial film of the oil droplets. Such an interfacial film can be confirmed using, for example, an optical microscope.

[0037] The present inventor has found that, for example, when a water-in-oil type emulsified composition is prepared by the liquid crystal emulsification method in which a linear higher fatty acid having 16 or more carbon atoms, a monohydric higher alcohol, and a nonionic surfactant are mixed while heating with an oil component to prepare a solution and adding it to heated water, oil droplets (emulsified particles) having such an interfacial film can be obtained.

[0038] The average particle size of the oil droplets, which are the dispersed phase, is not particularly limited. Such average particle size of the oil droplets can be, for example, 10 μm or less, 7 μm or less, 5 μm or less, or 3 μm or less immediately after production. The lower limit value of the average particle size is not particularly limited, but can be, for example, 500 nm or more, 700 nm or more, or 1 μm or more. Here, the average particle size of the oil droplets can be defined as the average value of the equivalent diameters of the projected areas of 10 or more, preferably 100 or more, oil droplets observed with an optical microscope.

[0039] (Oil content) The content of the oil in the oil-in-water emulsion cosmetic of the present disclosure is not particularly limited. For example, it can be 0.5% by mass or more, 1% by mass or more, 3% by mass or more, 5% by mass or more, 7% by mass or more, 10% by mass or more, 13% by mass or more, or 15% by mass or more, and can also be 50% by mass or less, 40% by mass or less, 30% by mass or less, 25% by mass or less, or 20% by mass or less, based on the total amount of the cosmetic.

[0040] The oil-in-water emulsion cosmetic of the present disclosure contains at least a volatile acyclic silicone oil as the oil. The volatile acyclic silicone oil can improve the film strength of the interfacial film of the oil droplets. Also, the use of the volatile acyclic silicone oil that can improve the film strength of the interfacial film can increase the static viscosity while suppressing the increase in the dynamic viscosity of the cosmetic, so that the increase in the viscosity ratio, that is, the feeling of collapse can be more easily expressed.

[0041] As the volatile acyclic silicone oil, for example, a volatile linear silicone oil or a volatile branched silicone oil can be used. Among them, a volatile linear silicone oil is preferred. The volatile acyclic silicone oil can be used alone or in combination of two or more.

[0042] Here, "volatile" is intended to mean a substance that exhibits a volatile content of more than 5% when left standing at 105°C for 3 hours under atmospheric pressure. From the perspective of obtaining excellent film strength and a crumbling feeling, the volatile content serving 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, as an indicator of volatility, the boiling point under 1 atm (101.325 kPa) can be used. From the perspective of obtaining excellent film strength and a crumbling feeling, this boiling point is preferably 250°C or lower, 240°C or lower, or 230°C or lower, and is also preferably 80°C or higher, 100°C or higher, 120°C or higher, 150°C or higher, or 160°C or higher. Further, in the present disclosure, "non-volatile" is intended to mean a substance that exhibits a volatile content of 5% or less when left standing at 105°C for 3 hours.

[0043] Examples of the volatile linear silicone oil 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. Here, these viscosities are intended to be the kinematic viscosities under a 25°C atmosphere.

[0044] Examples of the volatile branched silicone oil include low-molecular-weight branched siloxanes such as methyltrimethicone, tris(trimethylsilyl)methylsilane, and tetrakis(trimethylsilyl)silane.

[0045] The content of the volatile acyclic silicone oil in the water-in-oil type emulsified cosmetic of the present disclosure is not particularly limited. For example, it can be 0.1% by mass or more, 0.3% by mass or more, 0.5% by mass or more, 0.7% by mass or more, or 1.0% by mass or more based on the total amount of the cosmetic, and can also be less than 20.0% by mass, 15.0% by mass or less, 10.0% by mass or less, 9.0% by mass or less, 8.0% by mass or less, 7.0% by mass or less, 6.0% by mass or less, 5.0% by mass or less, 4.0% by mass or less, or 3.0% by mass or less. Alternatively, the content of the volatile acyclic silicone oil can be 15% by mass or more, 17% by mass or more, or 20% by mass or more based on the total amount of the oil component, and can also be about 100% by mass or less, less than about 100% by mass, about 90% by mass or less, about 80% by mass or less, about 70% by mass or less, about 60% by mass or less, about 50% by mass or less, about 40% by mass or less, or about 30% by mass or less.

[0046] In some embodiments, the water-in-oil type emulsified cosmetic of the present disclosure may contain a volatile cyclic silicone oil and a non-volatile acyclic silicone oil as the oil component. However, when a volatile acyclic silicone oil is blended to further improve the film strength of the interfacial film, the contents of the volatile cyclic silicone oil and the non-volatile acyclic silicone oil are each independently preferably less than 20.0% by mass, 15.0% by mass or less, 10.0% by mass or less, 7.0% by mass or less, 5.0% by mass or less, 3.0% by mass or less, or 1.0% by mass or less based on the total amount of the cosmetic. Alternatively, the contents of the volatile cyclic silicone oil and the non-volatile acyclic silicone oil are each independently preferably 10.0% by mass or less, 7.0% by mass or less, 5.0% by mass or less, 3.0% by mass or less, or 1.0% by mass or less based on the total amount of the oil component. Furthermore, it is more preferable that the volatile cyclic silicone oil and / or the non-volatile acyclic silicone oil are not blended in the oil component, and it is particularly preferable that the volatile cyclic silicone oil is not blended in the oil component.

[0047] In some embodiments, the water-in-oil emulsified cosmetic of the present disclosure can contain a polar oil as an oil component. Among the oil components, polar oils have oil properties and, due to their polarity, have a property of being more easily affinity with water than non-polar oils. Therefore, the emulsification balance between the aqueous phase and the oil phase is easily broken, and generally, it is difficult to improve the emulsification stability of a water-in-oil emulsified cosmetic containing a polar oil. However, as described above, the water-in-oil emulsified cosmetic of the present disclosure forms a strong interfacial film around the oil droplets (emulsified particles) and encapsulates the polar oil that easily disrupts the emulsification balance. Therefore, even when such a polar oil is used, good emulsification stability and a non-collapsing feeling can be exhibited.

[0048] As the polar oil, for example, it can contain at least one selected from a polar oil having an IOB of 0.10 or more and an ultraviolet absorber having an IOB of 0.10 or more. These oil components can be contained in an amount of 50% by mass or more, 60% by mass or more, 65% by mass or more, or 70% by mass or more based on the total amount of the oil components. There is no particular limitation on the upper limit value of these oil components, and for example, it can be 85% by mass or less, 80% by mass or less, or 75% by mass or less. Here, an organic ultraviolet absorber having an IOB of 0.10 or more can be regarded as a polar oil.

[0049] The IOB values of the polar oil and the ultraviolet absorber can be, for example, 0.10 or more, 0.11 or more, 0.12 or more, or 0.13 or more, and can also be 0.50 or less, 0.45 or less, or 0.40 or less. Here, the IOB value is an abbreviation of Inorganic / Organic Balance (inorganic / organic ratio), which is a value representing the ratio of the inorganic value to the organic value, and is an index indicating the degree of polarity of an organic compound. Specifically, the IOB value is expressed as IOB value = inorganic value / organic value. For each of the "inorganic value" and "organic value", 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, and the IOB value of the organic compound can be calculated by integrating the "inorganic value" and "organic value" of all atoms and functional groups in the organic compound (see, for example, Yoshiaki Koda, "Organic Conceptual Diagram - Basics and Applications -", pp. 11-17, Sankyo Publishing, issued in 1984).

[0050] Examples of polar oils with an IOB of 0.10 or more 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), isotridecyl isononanoate (IOB 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), 2-hexyldecyl adipate (IOB value = 0.16), diisopropyl sebacate (IOB value = 0.40), 2-ethylhexyl palmitate (IOB value = 0.13), 2-ethylhexyl ethylhexanoate (IOB value = 0.2), triisostearin (IOB value = 0.16), dipivalic acid PPG-3 (IOB value = 0.52), glyceryl tri(caprylic acid / capric acid) (IOB value = 0.33), etc. These polar oils can be used alone or in combination of two or more.

[0051] Examples of ultraviolet absorbers with an IOB of 0.10 or more include organic ultraviolet absorbers such as ethylhexyl methoxycinnamate, octocrylene, polysilicone-15, t-butylmethoxydibenzoylmethane, ethylhexyl triazone, bis-ethylhexyloxyphenol methoxyphenyl triazine, hexyl diethylaminohydroxybenzoyl benzoate, oxybenzone-3, methylene bisbenzotriazolyl tetramethylbutylphenol, homosalate, and ethylhexyl salicylate. These ultraviolet absorbers can be used alone or in combination of two or more.

[0052] (linear higher fatty acid having 16 or more carbon atoms) The content of the linear higher fatty acid having 16 or more carbon atoms in the oil-in-water emulsified cosmetic of the present disclosure is not particularly limited. For example, it can be 0.10% by mass or more, 0.15% by mass or more, 0.20% by mass or more, 0.25% by mass or more, or 0.30% by mass or more based on the total amount of the cosmetic, and can also be 5.0% by mass or less, 3.0% by mass or less, or 1.0% by mass or less.

[0053] The oil-in-water emulsified cosmetic of the present disclosure may contain higher fatty acids other than the linear higher fatty acid having 16 or more carbon atoms, for example, linear or branched higher fatty acids having less than 16 carbon atoms, or branched higher fatty acids having 16 or more carbon atoms, as long as it does not affect the effects of the present invention. However, from the viewpoints of collapse feeling and emulsion stability, these other higher fatty acids are preferably contained in a range of, for example, less than 0.10% by mass, 0.05% by mass or less, or 0.01% by mass or less based on the total amount of the cosmetic, and it is more preferable that these other higher fatty acids are not contained in the cosmetic.

[0054] The number of carbon atoms of the linear higher fatty acid can be 16 or more or 18 or more, and can also be 25 or less, 24 or less, or 22 or less.

[0055] Examples of such linear higher fatty acids include saturated fatty acids such as palmitic acid, stearic acid, arachidic acid, behenic acid, and lignoceric acid; and unsaturated fatty acids such as palmitoleic acid, oleic acid, linoleic acid, α-linolenic acid, γ-linolenic acid, arachidonic acid, eicosapentaenoic acid, and docosahexaenoic acid. Among them, from the viewpoint of the sense of collapse, saturated fatty acids are preferred, stearic acid and behenic acid are more preferred, and behenic acid is particularly preferred. These linear higher fatty acids can be used alone or in combination of two or more.

[0056] (Monohydric higher alcohol) The content of the monohydric higher alcohol in the oil-in-water emulsified cosmetic of the present disclosure is not particularly limited. For example, it can be 0.1% by mass or more, 0.3% by mass or more, 0.5% by mass or more, 0.7% by mass or more, or 1.0% by mass or more based on the total amount of the cosmetic, and can also be 5.0% by mass or less, 4.0% by mass or less, or 3.0% by mass or less.

[0057] The monohydric higher alcohol is not particularly limited. For example, a saturated or unsaturated monohydric aliphatic alcohol can be used, and it can be either linear or branched, but a linear form is preferred. From the viewpoints of emulsion stability and the sense of collapse, together with linear higher fatty acids and nonionic surfactants, a monohydric higher alcohol that is solid at normal temperature and is likely to form an interfacial film such as a gel film or a liquid crystal film based on a lamellar liquid crystal or the like at normal temperature or higher is preferred. Here, in the present disclosure, "normal temperature" means a range of 5°C to 35°C.

[0058] Examples of such monohydric higher alcohols include higher alcohols with a melting point of 40°C or higher, such as monohydric aliphatic alcohols having 10 to 30 carbon atoms. Specifically, for example, stearyl alcohol, isostearyl alcohol, oleyl alcohol, octyldodecanol, cholesterol, sitosterol, cetyl alcohol (cetanol), cetostearyl alcohol, decyltetradecanol, phytosterol, hexyl decanol, behenyl alcohol, lauryl alcohol, lanolin alcohol, hydrogenated lanolin alcohol, and the like can be mentioned. Among them, from the viewpoints of emulsion stability and collapse feeling, cetyl alcohol, isostearyl alcohol, stearyl alcohol, and behenyl alcohol are preferable, and behenyl alcohol is more preferable. These higher alcohols can be used alone or in combination of two or more.

[0059] From the viewpoints of emulsion stability, collapse feeling, etc., the mass ratio of the linear higher fatty acid having 16 or more carbon atoms to the monohydric higher alcohol is preferably 0.30 or more, 0.35 or more, 0.40 or more, 0.45 or more, 0.50 or more, 0.55 or more, 0.60 or more, or 0.65 or more, and is preferably 2.0 or less, 1.7 or less, 1.5 or less, or 1.3 or less.

[0060] (Nonionic surfactant) The content of the nonionic surfactant in the oil-in-water emulsion cosmetic of the present disclosure is not particularly limited. For example, it can be 0.1% by mass or more, 0.3% by mass or more, or 0.5% by mass or more based on the total amount of the cosmetic, and can also be 5.0% by mass or less, 4.0% by mass or less, 3.0% by mass or less, or 2.0% by mass or less.

[0061] There is no particular limitation on the nonionic surfactant, and examples thereof include polyoxyalkylene alkyl ethers, polyalkylene glycol fatty acid esters, POE alkyl ethers, POE·POP alkyl ethers, PEG fatty acid esters, polyglycerol fatty acid esters, POE glycerol fatty acid esters, isostearic acid PEG glyceryls, and silicone surfactants. These can be used alone or in combination of two or more.

[0062] Examples of the polyoxyalkylene alkyl ether include polyoxyethylene behenyl ether, polyoxyethylene stearyl ether, and the like.

[0063] Examples of the polyalkylene glycol fatty acid ester include polyethylene glycol monostearate, polyethylene glycol monooleate, and the like.

[0064] Examples of the 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, POE(15) oleyl ether, POE(20) oleyl ether, POE(50) oleyl ether, POE(10) behenyl ether, POE(20) behenyl ether, POE(30) behenyl ether, POE(2)(C12-15) alkyl ether, POE(4)(C12-15) alkyl ether, POE(10)(C12-15) alkyl ether, POE(5) secondary alkyl ether, POE(7) secondary alkyl ether, POE(9) alkyl ether, POE(12) alkyl ether, and the like.

[0065] 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, POE(30)POP(6) decyltetradecyl ether, and the like.

[0066] Examples of PEG fatty acid esters include, for example, polyethylene glycol monolaurate (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, PEG diisostearate, PEG(40) hydrogenated castor oil, PEG(50) hydrogenated castor oil, PEG(60) hydrogenated castor oil, PEG(100) hydrogenated castor oil, and the like.

[0067] Examples of polyglycerol fatty acid esters include, for example, hexaglyceryl monolaurate, hexaglyceryl monomyristate, hexaglyceryl monostearate, hexaglyceryl monooleate, decaglyceryl monolaurate, decaglyceryl monomyristate, decaglyceryl monostearate, decaglyceryl monoisostearate, decaglyceryl monooleate, decaglyceryl distearate, decaglyceryl diisostearate, and the like.

[0068] Examples of POE glycerol fatty acid esters include, for example, polyoxyethylene (POE)(5) glyceryl monostearate, POE(15) glyceryl monostearate, POE(5) glyceryl monooleate, POE(15) glyceryl monooleate, and the like.

[0069] Examples of isostearic acid PEG glyceryls include, for example, isostearic acid PEG(8) glyceryl, isostearic acid PEG(10) glyceryl, isostearic acid PEG(15) glyceryl, isostearic acid PEG(20) glyceryl, isostearic acid PEG(25) glyceryl, isostearic acid PEG glyceryl(30), isostearic acid PEG(40) glyceryl, isostearic acid PEG(50) glyceryl, isostearic acid PEG(60) glyceryl, and the like.

[0070] Examples of silicone surfactants include, for example, PEG(7) dimethicone, PEG(10) dimethicone, and the like.

[0071] Among these, from the viewpoints of emulsion stability, crumbling feeling, etc., PEG fatty acid esters, isostearic acid PEG glyceryls, and silicone surfactants are preferred, PEG(60) hydrogenated castor oil, isostearic acid PEG(60) glyceryl, and PEG(10) dimethicone are more preferred, and these may be used alone, but it is preferable to use them in combination.

[0072] 〈Optional Component〉 The water-in-oil type emulsified cosmetic of the present disclosure can be appropriately blended with various components as long as the effects of the present invention are not affected. Examples of the various components include additive components that can be usually blended in cosmetics. For example, humectants such as 1,3-butylene glycol, propylene glycol, and dynamite glycerin, anionic surfactants, cationic surfactants, amphoteric surfactants, water-soluble polymers, oil-soluble polymers, film-forming agents such as silicone polysaccharides, sequestering agents, lower alcohols such as ethanol, polyhydric alcohols such as PEG6000 and dipropylene glycol, higher alcohols other than the above, various extracts, sugars, amino acids, organic amines, polymer emulsions, chelating agents, ultraviolet absorbers other than the above, ultraviolet scattering agents such as zinc oxide, pH adjusters, skin nutrients, vitamins, pharmaceuticals, quasi-drugs, water-soluble drugs applicable to cosmetics, etc., whitening agents other than the above, anti-inflammatory agents other than the above, antioxidants, buffers, preservatives, antioxidant aids, thickeners, dispersants, propellants, organic powders, clay minerals, pigments, dyes, colorants, fragrances, acid components, alkali components, polar or non-polar oils other than the above, etc. These optional components can be used alone or in combination of two or more, and can be appropriately blended in the oil phase and / or the water phase.

[0073] Among such additives, from the viewpoints of suppressing crystallization of the interfacial film and the feeling of collapse, etc., it is preferable to use higher alcohols other than the above. As such higher alcohols, dihydric higher alcohols are preferable, and batyl alcohol is particularly preferable.

[0074] Also, generally, since it is difficult to improve the emulsion stability of a water-in-oil type emulsified cosmetic using a salt-type or acid-type whitening agent or anti-inflammatory agent and a polar oil, usually, a thickener, particularly a water-soluble thickener, is used to ensure the emulsion stability of such a cosmetic. However, although the blending of the thickener may improve the emulsion stability, there is a risk of adversely affecting the achievement of a specific viscosity ratio, i.e., the feeling of collapse, and it is likely to exhibit a sticky feeling.

[0075] On the one hand, the emulsion particles (oil droplets) in the water-in-oil emulsion cosmetic of the present disclosure are prepared using specific materials, namely, volatile acyclic silicone oil, linear higher fatty acids having 16 or more carbon atoms, monohydric higher alcohols, and nonionic surfactants, and have excellent emulsion stability. Therefore, the cosmetic of the present disclosure may not substantially contain a thickening agent. That is, the thickening agent may be blended at a ratio of 1% by mass or less, 0.5% by mass or less, 0.1% by mass or less, 0.01% by mass or less, or 0.001% by mass or less based on the total amount of the cosmetic. However, from the viewpoint of a sense of collapse or the like, it is advantageous not to use the thickening agent.

[0076] The water-in-oil emulsion cosmetic of the present disclosure may contain a whitening agent and / or an anti-inflammatory agent other than those described above. In such a case, at least one selected from a salt-type whitening agent, an acid-type whitening agent, a salt-type anti-inflammatory agent, and an acid-type anti-inflammatory agent can be contained in an amount of 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, or 90% by mass or more based on the total amount of the whitening agent component and the anti-inflammatory agent component. Here, examples of the whitening agent other than those described above include ascorbic acid derivatives (e.g., ascorbic acid glucoside), tranexamic acid derivatives, glycyrrhizic acid derivatives, nicotinic acid derivatives, kojic acid derivatives (e.g., kojic acid dipalmitate), ellagic acid derivatives, alkoxysalicylic acid derivatives, hydroquinone, α-arbutin, β-arbutin, nicotinamide, astaxanthin, histidine dithiooctanamide (Na / zinc), chamomile extract, licorice extract, placenta extract, rosemary extract, lucinol, and magnolignan. Examples of the anti-inflammatory agent other than those described above include glycyrrhizin and allantoin.

[0077] 《Use of the water-in-oil emulsion cosmetic》 The water-in-oil emulsion cosmetic of the present disclosure can exhibit a sense of collapse such that the viscosity of the cosmetic rapidly decreases when a load is applied. Therefore, the cosmetic of the present disclosure having such a feeling of use can be used, for example, as a cosmetic to be spread and applied to the skin or the like. Here, the cosmetic applied to the skin can also include those called external skin preparations.

[0078] There are no particular restrictions on the dosage form of the cosmetics of the present disclosure, and examples thereof include liquid, emulsion, cream, gel, spray, mousse, and the like. Here, in the present disclosure, "spray" can include mist-type sprays, aerosol-type sprays, and the like.

[0079] There are no particular restrictions on the product form of the cosmetics of the present disclosure, and examples thereof include facial cosmetics such as lotion, essence, emulsion, pack, etc.; makeup cosmetics such as foundation; sunscreen cosmetics (sunscreen agents); body cosmetics; skin cleansers such as makeup remover, body shampoo; hair cosmetics such as hair liquid, hair tonic, hair conditioner, shampoo, rinse, hair growth agents; ointments, and the like.

[0080] 《Method for Producing Oil-in-Water Emulsion Cosmetics》 The oil-in-water emulsion cosmetics of the present disclosure can be prepared by known methods such as the dispersion method and the aggregation method.

[0081] The dispersion method is a method of refining the mass of the dispersed phase by mechanical force. Specifically, it is a method of emulsification using the crushing force of an emulsifier, and examples of such a method include the high-pressure emulsification method of applying a high shear force using a high-pressure homogenizer.

[0082] The aggregation method is a colloid preparation method using interfacial chemical properties, which is a method of making a supersaturated state by some means from a uniformly dissolved state and causing the dispersed phase to appear. As specific techniques, the liquid crystal emulsification method, the HLB temperature emulsification method, the phase inversion emulsification method, the non-aqueous emulsification method, the D-phase emulsification method, and the like are known.

[0083] Among these methods, from the viewpoints of emulsion stability, collapse feeling, etc., the oil-in-water emulsion cosmetic of the present disclosure is advantageously prepared by the liquid crystal emulsification method. Near the interface of the emulsion particles prepared by the liquid crystal emulsification method, an interfacial film such as a gel film or a liquid crystal film based on a lamellar liquid crystal or the like is likely to be formed. As a result, aggregation and coalescence of the emulsion particles are suppressed, the emulsion stability is improved, and a strong interfacial film makes the collapse feeling more likely to appear.

[0084] As a method for preparing the cosmetic of the present disclosure by the liquid crystal emulsification method, for example, the following method can be adopted. Note that volatile acyclic silicone oil, linear higher fatty acid having 16 or more carbon atoms, monohydric higher alcohol, nonionic surfactant, and salt-type or acid-type whitening agent and / or salt-type or acid-type anti-inflammatory agent, optional components, etc. can be used in the same manner as those described above.

[0085] A volatile acyclic silicone oil, a linear higher fatty acid having 16 or more carbon atoms, a monohydric higher alcohol, a nonionic surfactant, and optionally an oil-soluble optional component are mixed while heating to about 70 to 90 °C to prepare an oil-phase solution. Next, water, a salt-type or acid-type whitening agent and / or a salt-type or acid-type anti-inflammatory agent, and optionally a water-soluble optional component are mixed while heating to about 70 to 90 °C to prepare an aqueous-phase solution. After gradually adding the oil-phase solution to this aqueous-phase solution while stirring, the oil-in-water emulsion cosmetic of the present disclosure can be prepared by cooling to room temperature.

[0086] In the conventional liquid crystal emulsification method, it has been confirmed that an interfacial film such as a gel film or a liquid crystal film based on a lamellar liquid crystal or the like is formed around the emulsion particles at the stage of cooling to room temperature. Therefore, it is considered that such an interfacial film is formed around the emulsion particles of the present disclosure at the same stage.

Examples

[0087] Examples are given below to explain the present invention in more detail, but the present invention is not limited thereto. In the following, unless otherwise specified, the blending amounts are shown in mass%.

[0088] Examples 1 to 3, Comparative Examples 1 to 4, and Reference Examples 1 to 3 For the oil-in-water emulsified cosmetics obtained by the formulations shown in Tables 1 to 2 and the production method shown below, the following evaluations were carried out, and the results are shown in Tables 1 to 2.

[0089] <Evaluation method> (Evaluation of viscosity) The viscosity of the cosmetic was evaluated using a B-type viscometer (TVB viscometer TVB-10, manufactured by Toki Sangyo Co., Ltd.) under the conditions of rotor number L3, 30 °C, 0.6 rpm, and 12 rpm. The results and the viscosity ratio calculated from the obtained results are summarized in a table. Here, in the table, the viscosity measured at 0.6 rpm is denoted as "V 0.6rpm ", the viscosity measured at 12 rpm is denoted as "V 12rpm ", and the viscosity ratio is denoted as "V 0.6rpm / V 12rpm ".

[0090] (Evaluation of emulsion stability) The size of the oil droplets within 1 hour after preparing the emulsified cosmetic and the size of the oil droplets after storage at 50 °C for 4 weeks were observed with an optical microscope, and the emulsion stability was evaluated according to the following criteria: A: There was almost no change in the oil droplet size. B: The oil droplet size increased slightly. C: The oil droplet size increased significantly, or the cosmetic separated.

[0091] <Production method of the cosmetic> (Example 1) Using the formulation shown in Table 1, an oil-in-water emulsified cosmetic was produced by the liquid crystal emulsification method shown below. Here, the numbers shown below correspond to the numbers of the component names on the left side of the formulation in Table 1.

[0092] While heating to 70 to 90 °C, the oil components of No. 6 to 7 and No. 9 to 12 were uniformly mixed, and then the nonionic surfactants of No. 1 and No. 2, the higher alcohols of No. 3 and No. 4, and behenic acid, which is a linear higher fatty acid of No. 5, were further mixed to prepare an oil-phase solution.

[0093] Subsequently, while heating to 70 - 90°C, materials No.13 - 20 and No.22 were added to ion-exchanged water No.23 and uniformly mixed to prepare an aqueous solution phase.

[0094] While heating the aqueous solution phase to 70 - 90°C, the oil phase solution was gradually added thereto, uniformly dispersed with a dispenser, and then cooled to room temperature to obtain an oil-in-water type emulsified cosmetic of Example 1.

[0095] (Example 2, Comparative Examples 1 - 2, and Reference Example 1) Except that the components and compounding amounts of the oil phase solution and the aqueous solution phase were changed to the components and compounding amounts shown in Table 1, in the same manner as in Example 1, oil-in-water type emulsified cosmetics of Example 2, Comparative Examples 1 - 2, and Reference Example 1 were obtained.

[0096] (Example 3, Comparative Examples 3 - 4, and Reference Examples 2 - 3) Except that the components and compounding amounts of the oil phase solution and the aqueous solution phase were changed to the components and compounding amounts shown in Table 2, in the same manner as in Example 1, oil-in-water type emulsified cosmetics of Example 3, Comparative Examples 3 - 4, and Reference Examples 2 - 3 were obtained.

[0097]

Table 1

[0098] 〈Results〉 From the results of Reference Example 1, when not containing an acid type whitening agent and a salt type whitening agent, for example, by adjusting the mass ratio of the linear higher fatty acid to the monohydric higher alcohol, a viscosity ratio of 7.9 or more can be achieved. However, as can be seen from the results of Comparative Example 2, when an acid type whitening agent is formulated, even if the mass ratio of the linear higher fatty acid to the higher alcohol is the same, a viscosity ratio of 7.9 or more cannot be achieved. Therefore, when applying and spreading the cosmetic of Comparative Example 2 on the skin, no sense of collapse was felt.

[0099] On the one hand, as is clear from the results of Examples 1 to 2, when volatile acyclic silicone oil (dimethicone (1.5 cst)) is used as the oil component, even if an acid-type whitening agent and a salt-type whitening agent are blended, the cosmetic has excellent emulsion stability and can achieve a viscosity ratio of 7.9 or more. When these cosmetics are applied to the skin and spread, it was confirmed that they exhibit a good crumbling feeling.

[0100] In addition, as can be seen by comparing Examples 1 to 2 and Comparative Example 1, it was found that when volatile acyclic silicone oil is used as the oil component, the viscosity ratio of the emulsified cosmetic can be increased.

[0101]

Table 2

[0102] 〈Results〉 As is clear from comparing Example 3 and Comparative Example 4, when volatile acyclic silicone oil is used as the oil component instead of non-volatile acyclic silicone oil, even if a whitening agent is blended, good emulsion stability can be exhibited, and it was also found that a viscosity ratio of 7.9 or more can be achieved.

[0103] As can be seen by comparing the results of Comparative Examples 2 to 3, when the proportion of polar oil in the oil component increases, the viscosity ratio tends to decrease. The cosmetic of Comparative Example 3 does not contain polar oil, but even in this case, it was confirmed that when it does not contain volatile acyclic silicone oil as the oil component and contains an acid-type whitening agent, a viscosity ratio of 7.9 or more cannot be achieved.

Claims

1. At least one selected from a whitening agent and an anti-inflammatory agent, a dispersion medium containing water, and oil droplets dispersed in the dispersion medium An oil-in-water emulsion cosmetic comprising: The oil droplets contain an oil component, a linear higher fatty acid having 16 or more carbon atoms, a monohydric higher alcohol, and a nonionic surfactant, The whitening agent contains at least one selected from a salt-type whitening agent and an acid-type whitening agent, The anti-inflammatory agent contains at least one selected from a salt-type anti-inflammatory agent and an acid-type anti-inflammatory agent, The oil component contains a volatile acyclic silicone oil, and the volatile acyclic silicone oil is contained in the oil component in an amount of 15% by mass or more and 40% by mass or less, The content of the thickening agent is 0.01% by mass or less, When using a B-type viscometer in an atmosphere of 30°C, the viscosity (V ０．６ｒｐｍ ), measured at 0.6 rpm, and the viscosity (V １２ｒｐｍ ), measured at 12 rpm, and the viscosity ratio (V ０．６ｒｐｍ / V １２ｒｐｍ ) is 7.9 or more. Oil-in-water emulsion cosmetic.

2. The cosmetic according to claim 1, wherein the mass ratio of the linear higher fatty acid to the monohydric higher alcohol is 0.30 or more.

3. The cosmetic according to claim 1 or 2, wherein the linear higher fatty acid, the higher alcohol, and the nonionic surfactant form an interfacial film of the oil droplets in an atmosphere at 25°C.

4. The cosmetic according to any one of claims 1 to 3, wherein the linear higher fatty acid is at least one selected from stearic acid and behenic acid, and the higher alcohol is at least one selected from cetyl alcohol, isostearyl alcohol, stearyl alcohol, and behenyl alcohol.

5. The cosmetic according to any one of claims 1 to 4, wherein the salt-type whitening agent is at least one selected from ascorbate, tranexamate, glycyrrhetinate, nicotinate, kojic acid salt, ellagic acid salt, 1-piperidinepropionate, 3-O-ethyl-L-ascorbate, and alkoxysalicylate, and the acid-type whitening agent is at least one selected from ascorbic acid, tranexamic acid, glycyrrhetinic acid, nicotinic acid, kojic acid, ellagic acid, 1-piperidinepropionic acid, 3-O-ethyl-L-ascorbic acid, and alkoxysalicylate.

6. The cosmetic according to any one of claims 1 to 5, wherein the anti-inflammatory agent is at least one selected from magnesium L-ascorbyl phosphate, dipotassium glycyrrhetinate, and ammonium glycyrrhetinate.

7. The cosmetic according to any one of claims 1 to 6, wherein at least one selected from the salt-type whitening agent, the acid-type whitening agent, the salt-type anti-inflammatory agent, and the acid-type anti-inflammatory agent is contained in an amount of 50% by mass or more based on the total amount of the whitening agent component and the anti-inflammatory agent component.

8. The cosmetic according to any one of claims 1 to 7, further comprising a divalent higher alcohol.

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