O / W / O emulsified composition

Abstract

The present application provides an O / W / O emulsion composition having excellent emulsion stability and use feeling. The O / W / O emulsion composition of the present application comprises (A) a nonionic surfactant having an HLB of 8 to 12, (B) a lipophilic surfactant having an HLB of 7 or less, (C) an internal phase oil component, and (D) an external phase oil component. The internal phase oil component (C) and the external phase oil component (D) are incompatible at a temperature of 0 to 60°C. The mixing ratio of the internal phase oil component (C) to the nonionic surfactant (A) (C / A ratio) is 0.8 to 3, and the mixing ratio of the external phase oil component (D) to the lipophilic surfactant (B) (D / B ratio) is 1 to 10.

Description

Technical Field

[0001] This invention relates to O / W / O type emulsion compositions. More specifically, it relates to O / W / O type emulsion compositions with excellent emulsion stability and user experience. Background Technology

[0002] O / W / O emulsions (oil-in-water-in-oil emulsions), also known as O / W / O composite emulsions or O / W / O multiple emulsions, are widely used in various industrial applications such as cosmetics, food, and pharmaceuticals. O / W / O emulsions have a structure where the inner and outer oil phases are separated by a water phase. Therefore, theoretically, two oils with different properties, such as silicone-based and non-silicone-based oils, can exist independently in a single emulsion. This allows for adjustments to the texture of cosmetics, inhibition of interactions between ingredients, and the achievement of more effective combinations.

[0003] However, in previous O / W / O type emulsion compositions, the emulsion stability was often insufficient. The inner oil phase and the outer oil phase would fuse over time, or the water phase would coalesce, which would eventually lead to the separation of oil and water.

[0004] To obtain a stable O / W / O type emulsion composition, for example, Japanese Patent Application Publication No. 10-28858 discloses a composition containing an organically modified clay mineral in the outer oil phase and an organosilicon-based oil in the inner oil phase. By having the organically modified clay mineral present in the outer oil phase, the aggregation of the inner and outer oil phases can be suppressed. Therefore, if an insoluble agent and a non-organosilicon-based oil are combined in one oil phase and an organosilicon-based oil is combined in the other oil phase, they can coexist stably in one system, preventing the precipitation of the agent and resulting in an emulsion with excellent user experience.

[0005] However, even O / W / O type emulsion compositions prepared using such methods struggle to prevent the fusion of internal oil components in the inner oil phase and external oil components in the outer oil phase. Furthermore, when the inner oil phase contains UV absorbers, oil-soluble pharmaceutical ingredients, etc., these components seep into the outer oil phase, resulting in a sticky, heavy feel when applied to the skin, which tends to impair the user experience. Therefore, improvements in emulsion stability and user experience remain crucial for O / W / O type emulsion compositions.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 10-28858 Summary of the Invention

[0009] The problem the invention aims to solve

[0010] The present invention was made in view of the aforementioned actual situation, and its object is to provide an O / W / O type emulsion composition with excellent emulsification stability and user experience.

[0011] Solution for solving the problem

[0012] In order to solve the above-mentioned problems, the inventors conducted in-depth research and found that by using incompatible oils that are usually difficult to select emulsifiers, emulsification conditions, etc., and are generally considered difficult to achieve good emulsification stability, in the internal phase oil and external phase oil, and by combining them with a specified surfactant under specific conditions, the above-mentioned problems can be solved, and the present invention was completed.

[0013] That is, the subject of this invention is an O / W / O type emulsion composition comprising:

[0014] (A) HLB is a nonionic surfactant of 8-12.

[0015] (B) Lipophilic surfactants with an HLB value of 7 or less.

[0016] (C) Internal phase oil content, and

[0017] (D) External phase oil content,

[0018] (C) The internal phase oil fraction and (D) the external phase oil fraction are immiscible at temperatures ranging from 0 to 60°C.

[0019] The ratio (C / A ratio) of internal phase oil to (A) nonionic surfactant is 0.8–3, and

[0020] The ratio of (D) external phase oil to (B) lipophilic surfactant (D / B ratio) is 1 to 10.

[0021] The effects of the invention

[0022] By configuring the O / W / O type emulsified composition of the present invention as described above, it is possible to suppress the fusion of the internal phase oil and the external phase oil, the separation of the aqueous phase, etc., thereby achieving excellent emulsification stability. In addition, since the internal phase oil is less likely to seep into the external phase, a non-sticky, well-spread, and generally excellent user experience can be achieved.

[0023] Furthermore, especially when formulated into sunscreen cosmetics, by incorporating UV absorbers as an internal phase oil, it not only provides a moisturizing and refreshing feel but also achieves a high level of UV protection. Therefore, it is unnecessary to incorporate UV scattering agents, or they can be reduced to a very small amount, thus avoiding the whitening problem caused by UV scattering agents. Detailed Implementation

[0024] The O / W / O type emulsifying composition of the present invention will be described in detail below.

[0025] It should be noted that, in the following text, polyethylene oxide is sometimes abbreviated as "POE", polypropylene oxide as "POP", and polyethylene glycol as "PEG".

[0026] <(A) A nonionic surfactant with HLB of 8-12>

[0027] The (A) nonionic surfactant used in the O / W / O type emulsifying composition of the present invention has an HLB of 8 or more, preferably 9 or more. Furthermore, the upper limit of HLB is 12 or less, preferably 11 or less. Here, "HLB (Hydrophile-lipophile balance)" generally represents the value of the surfactant's affinity for water and oil, and is a parameter known as the hydrophilic-lipophilic balance. HLB can be easily calculated, for example, by known calculation methods such as the Griffin method. The HLB based on the Griffin method can be calculated by the following formula:

[0028] HLB = 20 × total formula weight of hydrophilic portion / molecular weight

[0029] It should be noted that HLB in this invention is a weighted average of all (A) components.

[0030] (A) The preferred ingredient is a polyoxyalkylene surfactant. Specific examples include polyoxyalkylene hydrogenated castor oil (polyoxyethylene hydrogenated castor oil, etc.), fatty acid polyoxyalkylene glycerides (PEG-20 glyceryl isostearate, etc.), polyoxyalkylene alkyl ethers (PEG-20 oil ether, PEG-10 behenyl ether, PEG-20 behenyl ether, and PEG-30 behenyl ether, etc.), and fatty acid polyoxyalkylene dehydrated sorbitol (PEG-20 dehydrated sorbitol). Alcohol monolaurate, PEG-20 sorbitan monostearate and PEG-20 sorbitan monooleate, etc.), polyoxyalkylene phytosterols (PEG-10 phytosterol and PEG-30 phytosterol, etc.), polyoxyalkylene modified organosilicon (PEG-12 polydimethylsiloxane, etc.), PPG-20-decyltetradecyl alcohol polyether-10, PPG-13-decyltetradecyl alcohol polyether-24 and sucrose fatty acid esters (sucrose stearate), etc.

[0031] From the perspective of high safety to the skin and particularly excellent emulsification stability when the internal phase oil (C) contains polar oils (described later), component (A) is preferably composed only of polyoxyethylene hydrogenated castor oil (hereinafter referred to as "POE hydrogenated castor oil" or "PEG hydrogenated castor oil"), especially POE hydrogenated castor oil with an average POE addition mole number of 20 to 30. Here, "average POE addition mole number" refers not only to the number of POE added to a single POE hydrogenated castor oil, but also to the average number of POE added moles in each of two or more POE hydrogenated castor oils that have been mixed. For example, the average molar addition of POE in hydrogenated castor oil made by mixing POE hydrogenated castor oil with an addition of 20 moles of POE and POE hydrogenated castor oil with an addition of 30 moles of POE in a 2:3 (mass ratio) ratio is (20×2+30×3) / (2+3)=26.

[0032] Commercially available products of POE hydrogenated castor oil include POE(20) hydrogenated castor oil (HLB10, NIKKOL HCO-20), POE(30) hydrogenated castor oil (HLB11, NIKKOL HCO-30) (all manufactured by Nikko Chemicals Co., Ltd.), and EMLEX HC-30 (manufactured by NIHON EMULSION Co., Ltd.).

[0033] The preferred amount of (A) nonionic surfactant is determined based on the amount of (C) internal phase oil. In the O / W / O type emulsified composition of the present invention, the ratio of (C) internal phase oil to (A) nonionic surfactant, i.e., the ratio of [(C) internal phase oil amount (mass%)] / [(A) nonionic surfactant amount (mass%)] (hereinafter sometimes referred to as the "C / A ratio"), is 0.8 or more, preferably 0.9 or more, more preferably 1 or more, and also 3 or less, preferably 2.5 or less, more preferably 2 or less. Therefore, examples of C / A ratio ranges include 0.8 to 3, preferably 0.9 to 2.5, and more preferably 1 to 2.

[0034] <(B) Lipophilic surfactants with an HLB value of 7 or less>

[0035] As the (B) lipophilic surfactant used in the O / W / O type emulsified composition of the present invention, a lipophilic surfactant with an HLB of 7 or less can be used, and an organosilicon surfactant is particularly preferred.

[0036] Examples of silicone surfactants with an HLB value of 7 or less include polyoxyalkylene-modified silicones, polyoxyalkylene / alkyl co-modified silicones, polyglycerol-modified silicones, and / or polyglycerol / alkyl co-modified silicones. Specific examples include KF-6017 (PEG-10 polydimethylsiloxane, manufactured by Shin-Etsu Chemical Co., Ltd.), KF-6028 (PEG-9 polydimethylsiloxane-ethyl polydimethylsiloxane, manufactured by Shin-Etsu Chemical Co., Ltd.), and KF-6038 (lauryl PEG-9 polydimethylsiloxane-ethyl polydimethylsiloxane, manufactured by Shin-Etsu Chemical Co., Ltd.).

[0037] (B) The preferred amount of the lipophilic surfactant is determined based on the amount of the external phase oil (D) described later. In the O / W / O type emulsifying composition of the present invention, the ratio of the external phase oil (D) to the lipophilic surfactant (B), i.e., the ratio of [the amount of external phase oil (mass%)] to [the amount of lipophilic surfactant (B)] (hereinafter sometimes referred to as the "D / B ratio"), is 1 or more, preferably 2 or more, more preferably 4 or more, and also 10 or less, preferably 8 or less, more preferably 6 or less. Therefore, examples of the D / B ratio range include 1 to 10, preferably 2 to 8, and more preferably 4 to 6.

[0038] <(C) Internal phase oil content and (D) External phase oil content>

[0039] The (C) internal phase oil and (D) external phase oil used in the O / W / O type emulsion composition of the present invention are an incompatible combination at temperatures ranging from 0 to 60°C. There are no particular restrictions on the combination of (C) internal phase oil and (D) external phase oil as long as they are incompatible with each other. Generally speaking, by selecting the internal phase oil with a higher polarity than the external phase oil with (D), there is a tendency to achieve better emulsion stability and user experience.

[0040] The term "incompatible" in this specification is defined as follows.

[0041] After heating and melting the (C) internal phase oil fraction and (D) external phase oil fraction as needed, stir and mix them with [internal phase oil fraction]:[external phase oil fraction]=1:1 (mass ratio). Then, when the mixture is left to stand in the temperature range of 0 to 60°C, the state in which the boundary of the mixture is uniformly separated into two layers is recorded as "incompatible", and the state in which there is no boundary and is transparent is recorded as "compatible".

[0042] As oily components used in both the (C) internal phase oil and (D) external phase oil, they can be combined with oily components commonly used in cosmetics and topical skin agents, provided they are incompatible with each other. Examples include avocado oil, camellia seed oil, macadamia seed oil, corn oil, olive fruit oil, rapeseed oil, sesame seed oil, almond oil, wheat germ oil, camellia seed oil, castor seed oil, linseed oil, safflower seed oil, cottonseed oil, evening primrose oil, perilla seed oil, soybean oil, peanut oil, tea seed oil, torreya seed oil, rice bran oil, tung oil, Japanese tung oil, jojoba seed oil, wheat germ oil, triglycerides, tricaprylic acid glycerides, and triisopalmitoyl triglycerides (liquid oils), isopropyl myristate, cetyl ethylhexanoate, octyl dodecyl myristate, isopropyl palmitate, and hard... Butyl oleate, hexyl laurate, myristyl myristate, decyl oleate, hexyl decyl dimethyl octanoate, cetyl lactate, myristyl lactate, acetylated lanolin, isocetyl stearate, isocetyl isostearate, cholesterol 12-hydroxystearate, ethylene glycol bis(2-ethylhexanoate), dipentaerythritol fatty acid ester, N-alkyl diol monoisostearate, neopentyl glycol didecanoate, diisostearate malate, di(2-heptyl undecanoate) glycerol, trimethylolpropane tri-2-ethylhexanoate, pentaerythritol tetra-2-ethylhexanoate, glycerol Tri-2-ethylhexanoate, trimethylolpropane triisostearate, cetyl-2-ethylhexanoate, 2-ethylhexyl palmitate, glyceryl trimyristate, glyceryl tri(2-heptylundecanoate), methyl castor oil, oleyl oleate, octadecyl alcohol, acetylglycine, 2-heptylundecyl palmitate, diisopropyl adipate, N-lauroyl-L-glutamic acid-2-octyldodecyl ester, di(2-heptylundecyl) adipate, ethyl laurate, di(2-ethylhexyl) sebacate, 2-hexyldecyl myristate, palmitic acid- Ester oils such as 2-hexyldecyl adipic acid, 2-hexyldecyl adipate, diisopropyl sebacate, 2-ethylhexyl succinate, ethyl acetate, butyl acetate, amyl acetate, and triethyl citrate; chain polysiloxanes such as dimethyl polysiloxane, methylphenyl polysiloxane, methylhydropolysiloxane, octyl polymethylsiloxane, and diphenylsiloxyphenyl polytrimethylsiloxane; modified silicone oils such as amino-modified silicone oil, epoxy-modified silicone oil, epoxy / polyether-modified silicone oil, polyether-modified silicone oil, carboxyl-modified silicone oil, alcohol-modified silicone oil, alkyl-modified silicone oil, ammonium salt-modified silicone oil, and fluorine-modified silicone oil.

[0043] From the viewpoint of achieving exceptionally good emulsification stability and user experience, (C) the internal phase oil component preferably contains polar oil.

[0044] Polar oils are widely used in cosmetics and topical skincare products for purposes such as improving viscosity, hardness, and other tactile properties; imparting pharmacological effects such as moisturizing, UV protection, and whitening; and functioning as solvents for oil-soluble components. However, on the other hand, they tend to cause stickiness and poor spreadability, and also have poor compatibility with non-polar oils such as silicone oils and hydrocarbon oils. Therefore, they tend to compromise emulsion stability in O / W / O type emulsion compositions with two oil phases. In the O / W / O type emulsion composition of the present invention, the (C) internal phase oil fraction does not easily blend with the (D) external phase oil fraction, and the polar oil remains stably in the internal oil phase. Therefore, it is possible to suppress the problems caused by polar oils to the usability and emulsion stability of the composition.

[0045] The polar oil in this invention is an oil with an IOB value of 0.1 or higher, and particularly preferably an IOB value greater than 0.1 and less than 0.8.

[0046] The IOB value is short for Inorganic / Organic Balance, which represents the ratio of inorganic value to organic value. It is an indicator of the polarity of an organic compound. Specifically, the IOB value is expressed as IOB value = Inorganic value / Organic value. Regarding "inorganic value" and "organic value," for example, the "organic value" of one carbon atom in a molecule is 20, and the "inorganic value" of one hydroxyl group is 100, corresponding to various atoms or functional groups. By summing the "inorganic value" and "organic value" of all atoms and functional groups in an organic compound, the IOB value of that organic compound can be calculated (see, for example, Yoshio Koda, *Organic Concept Map - Fundamentals and Applications -*, pp. 11-17, Sankyo Publishing, 1984).

[0047] Examples of polar oils that meet these conditions include:

[0048] Fatty acids such as oleic acid (IOB value = 0.42) and isostearic acid (IOB value = 0.43);

[0049] Isopropyl myristate (IOB value = 0.18), Ethylhexyl 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), Glycol distearate (IOB value = 0.16), Glyceryl diisostearate (IOB value = 0.29), Neopentyl glycol didecanoate (IOB value = 0.25) Ester oils including diisostearyl malate (IOB value = 0.28), trimethylolpropane triisostearyl (IOB value = 0.16), glyceryl tri(2-ethylhexanoate) (IOB value = 0.35), trimethylolpropane tri(ethylhexanoate) (IOB value = 0.33), diisobutyl adipic acid (IOB value = 0.46), N-lauroyl-L-glutamic acid-2-octyl dodecyl ester (IOB value = 0.29), 2-hexyl decyl adipic acid (IOB value = 0.16), diisopropyl sebacate (IOB value = 0.40), ethylhexyl methoxycinnamate (IOB value = 0.28), and ethylhexyl salicylate (IOB value = 0.60);

[0050] Vegetable oils such as olive fruit oil (IOB=0.16), macadamia seed oil (IOB=0.17), and castor seed oil (IOB=0.42);

[0051] Higher alcohols such as decyltetradecyl alcohol (IOB=0.21), octyldodecyl alcohol (IOB=0.26), and oleyl alcohol (IOB=0.28); etc.

[0052] (C) The amount of internal phase oil relative to the total amount of the O / W / O type emulsion composition is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, and preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less. Therefore, examples of the range of the amount of internal phase oil in (C) include 1 to 30% by mass, 3 to 25% by mass, and 5 to 20% by mass.

[0053] (D) There are no particular restrictions as long as the external phase oil is incompatible with the internal phase oil in (C). Considering good spreadability, a refreshing feel, non-stickiness, excellent water and oil resistance, and resistance to being easily washed away by sweat or water, silicone oils such as dimethylpolysiloxane are preferred. However, since cyclic silicone oils are readily compatible with polar oils, especially when the internal phase oil in (C) contains polar oil, the external phase oil in (D) is preferably free of cyclic silicone oil.

[0054] Preferred examples of silicone oils include chain silicone oils such as dimethicone (polydimethylsiloxane), methylphenyl polysiloxane, octyl polymethylsiloxane, diphenylsiloxyphenyl polytrimethylsiloxane, and methylhydropolysiloxane.

[0055] (D) The amount of external phase oil relative to the total amount of the O / W / O type emulsion composition is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 30% by mass or less. Therefore, examples of the range for the amount of external phase oil in (D) include 5 to 40% by mass, 10 to 35% by mass, and 15 to 30% by mass.

[0056] <Optional Ingredients>

[0057] In the O / W / O type emulsified composition of the present invention, in addition to the aforementioned essential components (A), (B), (C), and (D), other components commonly used in cosmetics and topical skin preparations may be added as appropriate, without impairing the effects of the present invention. For example, in addition to aqueous phase thickeners, oil phase thickeners, ultraviolet absorbers, and oil-soluble pharmaceutical ingredients, chelating agents, preservatives, antioxidants, etc., may also be added as needed.

[0058] <(E) Aqueous Thickener>

[0059] Examples of (E) aqueous phase thickeners include plant-based polymers such as gum arabic, tragacanth gum, galactomannan, locust bean gum, guar gum, ark sylvestris gum, carrageenan gum, xanthan gum, pectin, agar, quince seeds (quince) and seaweed gum (brown algae extract), microbial polymers such as gellan gum, dextran, succinyl dextran and budding stalk polysaccharide, and starch-based polymers such as starch (rice, corn, potato, wheat), carboxymethyl starch and methyl hydroxypropyl starch.

[0060] In addition, examples include cellulose-based polymers such as methylcellulose, nitrocellulose, ethylcellulose, methyl hydroxypropylcellulose, hydroxyethylcellulose, sodium cellulose sulfate, hydroxypropylcellulose, sodium carboxymethyl cellulose, microcrystalline cellulose, and cellulose powder, as well as alginate-based polymers such as sodium alginate and propylene glycol alginate.

[0061] Furthermore, examples include vinyl polymers such as polyvinyl methyl ether and carboxyvinyl polymers, polyoxyethylene polymers, polyoxyethylene-polyoxypropylene copolymers, acrylic polymers such as ethyl polyacrylate and polyacrylamide, polyethyleneimine, cationic polymers, bentonite, magnesium aluminum silicate, lithium soapstone (Laponite), hydropyrite, anhydrous silica, and other inorganic water-soluble polymers, PEG-240 / HDI copolymer bis-decyltetradecyl alcohol polyether-20 ether, dimethacrylamide / sodium acryloyl dimethyl taurate crosslinked polymer, sodium acrylate / sodium acryloyl dimethyl taurate copolymer, acrylates / stearyl alcohol polyether-20 methacrylate copolymer, ammonium acryloyl dimethyl taurate / VP copolymer, and polyacrylate-1 (a crosslinked polymer copolymerized from vinylpyrrolidone, N,N-dimethylaminoethyl methacrylate, stearyl alcohol acrylate, and tripropylene glycol diacrylate).

[0062] From the perspective of providing excellent thickening effect without compromising emulsification stability, PEG-240 / HDI copolymer bis-decyltetradecyl alcohol polyether-20 ether is preferred. Particularly preferred are those represented by the following formula (I):

[0063] R 1 -{(OR 2 ) k -OCONH-R 3 [-NHCOO-(R 4 -O) n -R 5 ] h} m (I)

[0064] (In the above formula (I), R) 1 =Ethyl, R 2 and R 4 Ethylene and R, respectively 3 = Hexamethylene, R 5 =2-decyltetradecyl, h=1, m=2, k=120, n=20). Commercially available examples include ADEKA NOL GT-730 (manufactured by ADEKA Co., Ltd.).

[0065] <(F) Oil Phase Thickener>

[0066] Examples of (F) oil phase thickeners include dextrin fatty acid esters, sucrose fatty acid esters, fatty acids or their salts, hydrogenated vegetable oils or solid or semi-solid vegetable oils, organically modified clay minerals, glycerol fatty acid esters and amino acid-based gelling agents.

[0067] Dextrin fatty acid esters are esters of dextrin or reduced dextrin with higher fatty acids. They can be used without particular restrictions as long as they are substances commonly used in cosmetics. Dextrin or reduced dextrin with an average degree of polymerization of 3 to 100 is preferred. Furthermore, saturated fatty acids with 8 to 22 carbon atoms are preferred as the constituent fatty acids of dextrin fatty acid esters. Specifically, examples include dextrin palmitate, dextrin oleate, dextrin stearate, dextrin myristate, and dextrin palmitate / 2-ethylhexanoate.

[0068] Sucrose fatty acid esters are preferably those whose fatty acids are linear or branched, saturated or unsaturated, and have 12 to 22 carbon atoms. Specifically, examples include sucrose caprylate, sucrose decanoate, sucrose laurate, sucrose myristate, sucrose palmitate, sucrose stearate, sucrose oleate, sucrose erucate, and sucrose tetrastearate triacetate.

[0069] Fatty acids can be those that are solid at room temperature (25°C), such as myristic acid, palmitic acid, stearic acid, and behenic acid. Additionally, their calcium, magnesium, and aluminum salts can be listed as salts.

[0070] Examples of hydrogenated vegetable oils include hydrogenated palm kernel oil, hydrogenated castor oil, hydrogenated peanut oil, hydrogenated rapeseed oil, hydrogenated palm oil, hydrogenated camellia seed oil, hydrogenated soybean oil, hydrogenated olive oil, hydrogenated macadamia seed oil, hydrogenated sunflower seed oil, hydrogenated wheat germ oil, hydrogenated rice germ oil, hydrogenated rice bran oil, hydrogenated cottonseed oil, and hydrogenated avocado oil.

[0071] In addition, similar to hydrogenated vegetable oils, vegetable oils that are solid or semi-solid at room temperature can also be used. Here, solid oil refers to oil that is solid at 25°C, and semi-solid oil refers to oil that is solid at 25°C in half its volume. More specifically, oils with a melting point in the range of 44°C to 90°C and a viscosity of 5000 mPa·s or more, and further 10000 mPa·s or more, as measured using a type B viscometer at 25°C, are preferred. Examples of vegetable oils that are solid or semi-solid at room temperature include cocoa butter, coconut oil, oil palm oil, oil palm kernel oil, lacquer fruit wax, and shea butter.

[0072] Organically modified clay minerals are a type of colloidal hydrous aluminum silicate with a three-layer structure. They can be substances prepared by modifying the clay minerals shown in the following general formula (1) with quaternary ammonium salt cationic surfactants.

[0073] (X,Y) 2―3 (Si,Al)4O 10 (OH)2Z 1 / 3 ·nH2O (1)

[0074] (Where, X=Al, Fe(III), Mn(III), Cr(III), Y=Mg, Fe(II), Ni, Zn, Li, Z=K, Na, Ca)

[0075] Specifically, it is obtained by treating natural or synthetic montmorillonite groups (commercially available products include Veegum, Kunipia, Laponite, etc.) such as montmorillonite, saponite, and hydropyrite (in which case the (OH) group in the formula is replaced by fluorine) and synthetic mica known by the names sodium silicate mica, sodium or lithium band mica (commercially available products include Dimonite: Topy Industries, Ltd., etc.) with quaternary ammonium salt cationic surfactants.

[0076] The quaternary ammonium salt cationic surfactant used herein is represented by the following general formula (2).

[0077]

[0078] (where R is in the formula) 1 R represents an alkyl or benzyl group with 10 to 22 carbon atoms. 2 R represents a methyl group or an alkyl group having 10 to 22 carbon atoms. 3 and R 4 (This indicates an alkyl or hydroxyalkyl group with 1 to 3 carbon atoms; X represents a halogen atom or a methyl sulfate residue.)

[0079] Examples of quaternary ammonium salt-type cationic surfactants include, for example, dodecyltrimethylammonium chloride, myristyltrimethylammonium chloride, cetyltrimethylammonium chloride, stearyltrimethylammonium chloride, alkyltrimethylammonium chloride, behenyltrimethylammonium chloride, myristyl dimethyl ethyl ammonium chloride, cetyl dimethyl ethyl ammonium chloride, stearyl dimethyl ethyl ammonium chloride, alkyl dimethyl ethyl ammonium chloride, behenyl dimethyl ethyl ammonium chloride, myristyl diethyl methyl ammonium chloride, and cetyl... Diethylmethylammonium chloride, stearyldiethylmethylammonium chloride, alkyldiethylmethylammonium chloride, behenyldiethylmethylammonium chloride, benzyldimethylmyristylammonium chloride, benzyldimethylcetylammonium chloride, benzyldimethylstearylammonium chloride, benzyldimethylbehenylammonium chloride, benzylmethylethylcetylammonium chloride, benzylmethylethylstearylammonium chloride, dibehenyldihydroxyethylammonium chloride and corresponding bromides, and further, dipalmitoylpropylethylammonium methyl sulfate, etc. In practicing this invention, one or more of these compounds may be selected arbitrarily.

[0080] Representative organically modified clay minerals include dimethyl dioctadecylammonium montmorillonite (distearate dimethylammonium lithium montmorillonite), dimethyl alkylammonium hydrogloss, benzyl dimethyl stearylammonium lithium montmorillonite, and distearate dimethylammonium chloride-treated magnesium aluminum silicate. Distearate dimethylammonium lithium montmorillonite is particularly preferred. Commercially available products include BENTONE 27 (benzyl dimethyl stearylammonium chloride-treated hydrogloss: manufactured by Elementis Japan) and BENTONE 38 (distearate dimethylammonium chloride-treated hydrogloss: manufactured by Elementis Japan).

[0081] Glyceryl fatty acid esters are esterification products obtained by reacting glycerol, a diacid with 18 to 28 carbon atoms, and a fatty acid with 8 to 28 carbon atoms (excluding the diacid). As long as it is a substance commonly used in cosmetics, it can be used without particular restrictions. Specifically, examples include glycerol (behenic acid / isostearic acid / eicosanoic acid) esters, glyceryl behenate / eicosanoic acid esters, and polyglycerol-10 behenate / eicosanoic acid esters.

[0082] Amino acid-based gelling agents include dibutyllauroyl glutamine, dibutylethylhexanoyl glutamine, polyamide-8, polyamide-3, and N-lauroyl-L-glutamic acid dibutylamide.

[0083] Of the above, from the perspective of having excellent thickening effect and helping to improve emulsion stability, it is preferable to combine distearate dimethylammonium lithium montmorillonite in the (D) external phase oil fraction.

[0084] <(G) Ultraviolet Absorber>

[0085] When the O / W / O type emulsified composition of the present invention is intended for use as a sunscreen cosmetic, it may be combined with (G) an ultraviolet absorber as (C) an internal phase oil or aqueous phase component.

[0086] (G) The ultraviolet absorber is not particularly limited, and examples include benzoic acid derivatives, salicylic acid derivatives, cinnamic acid derivatives, dibenzoylmethane derivatives, β,β-diphenylacrylate derivatives, benzophenone derivatives, benzyl camphor derivatives, benzyl camphor derivatives, phenylbenzimidazole derivatives, triazine derivatives, phenylbenzotriazole derivatives, anthranilic acid derivatives, imidazoline derivatives, benzyl malonate derivatives, and 4,4-diarylbutadiene derivatives. Specific examples of these ultraviolet absorbers will be described below, but the present invention is not limited to these examples.

[0087] Examples of benzoic acid derivatives include, but are not limited to, ethyl p-aminobenzoic acid (PABA), ethyl dihydroxypropyl PABA, ethylhexyl dimethyl PABA, glycerol PABA, PEG-25-PABA, and diethylaminohydroxybenzoyl benzoate.

[0088] Examples of salicylic acid derivatives include ethylhexyl salicylate, homosalyl salicylate, dipropylene glycol salicylate, and TEA salts of salicylic acid, but these are not limited to these.

[0089] Examples of cinnamic acid derivatives include ethylhexyl methoxycinnamate, isopropyl methoxycinnamate, isoamyl methoxycinnamate, cinnoxalate, DEA salt of methoxycinnamate, methyl diisopropyl cinnamate, and glyceryl ethylhexanoate dimethoxycinnamate, but are not limited to these.

[0090] Examples of dibenzoylmethane derivatives include 4-tert-butyl-4'-methoxydibenzoylmethane, but it is not limited to these.

[0091] Examples of β,β-diphenylacrylate derivatives include octocrylene, but the list is not limited to these.

[0092] Examples of benzophenone derivatives include benzophenone-1, benzophenone-2, benzophenone-3 or oxybenzone, benzophenone-4, benzophenone-5, benzophenone-6, benzophenone-8, benzophenone-9 and benzophenone-12, but are not limited to these.

[0093] Examples of benzylidene camphor derivatives include terephthaloyl dicamphor sulfonic acid, but it is not limited to these.

[0094] Examples of benzylidene camphor derivatives include 3-benzylidene camphor, 4-methylbenzylidene camphor, benzylidene camphor sulfonic acid, camphor benzalkonium methyl sulfate, terephthalimide dicamphor sulfonic acid, and polyacrylamide methylbenzylidene camphor, but are not limited to these.

[0095] Examples of phenylbenzimidazole derivatives include phenylbenzimidazole sulfonic acid and disodium phenyldibenzimidazole tetrasulfonic acid, but these are not the only ones that can be listed.

[0096] Examples of triazine derivatives include bis-ethylhexyloxyphenol methoxyphenyl triazine, ethylhexyl triazine ketone, diethylhexylbutamidotriazine ketone, and 2,4,6-tris(diisobutyl-4'-aminobenzylmalonate)-triazine, but are not limited to these.

[0097] Examples of phenylbenzotriazole derivatives include cresoltrazol trisiloxane and methylenebis-benzotriazole tetramethylbutylphenol, but are not limited to these.

[0098] Examples of anthranilic acid derivatives include menthyl anthranilate, but the list is not limited to these.

[0099] Examples of imidazoline derivatives include dimethoxybenzyldioxoimidazoalkyl propionate ethylhexyl ester, but the list is not limited to these.

[0100] Examples of benzyl malonic acid ester derivatives include, but are not limited to, polyorganosiloxanes having benzyl malonic acid ester functional groups (e.g., polysiloxane-15).

[0101] Examples of 4,4-diarylbutadiene derivatives include 1,1-dicarboxy(2,2'-dimethylpropyl)-4,4-diphenylbutadiene, but the list is not limited to these.

[0102] (G) UV absorbers usually tend to produce stickiness or reduce emulsion stability, but the O / W / O type emulsion composition of the present invention does not easily produce the fusion of the inner oil phase and the outer oil phase or the separation of the aqueous phase. Therefore, by combining (G) UV absorbers in the inner oil phase or the aqueous phase, the problems of stickiness and emulsion stability can be suppressed.

[0103] Furthermore, the O / W / O type emulsion composition of the present invention achieves a high UV protection effect, thus eliminating the need for UV scattering agents, which contribute to whitening and powdery textures. While the mechanism of action for achieving this high UV protection effect is not yet fully understood, it is believed that the O / W / O type emulsion composition of the present invention, due to the stable retention of emulsion particles, allows the oil and water phases to spread uniformly upon application to the skin, resulting in a uniform film formation.

[0104] <(H) Oil-soluble pharmaceutical components>

[0105] In addition to imparting whitening, acne prevention, and anti-wrinkle effects to the O / W / O type emulsified composition of the present invention, various (H) oil-soluble pharmaceutical components can also be combined as (C) internal phase oil components.

[0106] (H) Oil-soluble pharmaceutical ingredients can be selected from components that have been used in cosmetics and topical skin agents. Specific examples include vitamins such as vitamin A and its derivatives, vitamin D and its derivatives, vitamin E and its derivatives, vitamin K and its derivatives, sterols, and natural and synthetic (daily) fragrances. By combining (H) oil-soluble pharmaceutical ingredients as the (C) internal phase oil, various pharmaceutical effects can be imparted while avoiding problems such as stickiness and emulsification stability.

[0107] <Emulsified Particle Size>

[0108] The emulsified particles formed by the (C) internal phase oil fraction of the O / W / O type emulsified composition of the present invention preferably have a particle size of less than 200 nm, more preferably less than 100 nm. If the emulsified particle size is less than 200 nm, superior emulsification stability can be achieved. It should be noted that the "emulsified particle size" in the present invention is a value measured at 25°C based on dynamic light scattering.

[0109] <Preparation Method>

[0110] The O / W / O type emulsion composition of the present invention can be manufactured using conventionally known methods for producing composite emulsions. For example, a so-called two-stage emulsification method can be used: using a nonionic surfactant with an HLB of 8 to 12, an O / W type emulsion prepared by finely emulsifying the internal phase oil fraction (C) in an aqueous phase is further emulsified into an external phase oil fraction (D) containing a lipophilic surfactant with an HLB of 7 or less (B).

[0111] <Applications>

[0112] The O / W / O type emulsified composition of the present invention can be widely used in sunscreen cosmetics, skin care cosmetics, color cosmetics such as foundation, and topical skin agents with pharmacological effects.

[0113] Example

[0114] The following examples further illustrate the invention in detail, but the invention is not limited thereto. Unless otherwise specified, the amount of each component is expressed as a percentage of mass relative to the system containing that component. Before detailing the various examples, the evaluation methods used are explained.

[0115] <Emulsification Stability>

[0116] Visual inspection and microscopy were used to confirm how the state of the emulsified particles in the sample stored at 50°C for one month changed compared to the sample stored at 25°C for one month.

[0117] (Evaluation Criteria)

[0118] A: No change

[0119] B: Some changes in the state of the emulsion particles were observed, but within acceptable limits.

[0120] C: Observation of emulsified particles becoming enlarged due to aggregation, or separation of oil and water.

[0121] User Experience

[0122] Professional reviewers applied the prepared sample to the skin and evaluated the presence or absence of stickiness and the goodness of spreadability.

[0123] (Evaluation Criteria)

[0124] A: Good

[0125] B: Ordinary

[0126] C: Poor

[0127] <Examples 1-4 and Comparative Examples 1-3>

[0128] O / W / O type emulsion compositions with the compositions described in Table 1 below were prepared. The emulsion stability and user experience of each sample were evaluated according to the evaluation methods described above.

[0129] [Table 1]

[0130]

[0131] As shown in Table 1 above, when the (C) internal phase oil and (D) external phase oil, which are incompatible within a temperature range of 0 to 60°C, are included, an O / W / O type emulsion composition with excellent emulsification stability and user experience is obtained (Examples 1 to 4). On the other hand, when a combination is used in which the (C) internal phase oil and (D) external phase oil are compatible within a temperature range of 0 to 60°C, it is confirmed that the emulsification stability is significantly worse (Comparative Examples 1 to 3).

[0132] <Example 5 and Comparative Examples 4-7>

[0133] O / W / O type emulsion compositions with the compositions described in Table 2 below were prepared. The emulsion stability and user experience of each sample were evaluated according to the evaluation methods described above.

[0134] [Table 2]

[0135]

[0136] As shown in Table 2 above, when a nonionic surfactant with an HLB of 8 to 12 (A) is included, an O / W / O type emulsion composition with excellent emulsification stability and user experience is obtained (Example 5). On the other hand, when a nonionic surfactant with an HLB of less than 8 or more than 12 is included, the emulsification stability is poor (Comparative Examples 4 and 5). In addition, it was confirmed that even when a nonionic surfactant with an HLB of 8 to 12 (A) is included, if the ratio of the internal phase oil (C) to the nonionic surfactant (A) (C / A ratio) exceeds 3, sufficient emulsification stability cannot be achieved (Comparative Example 6), and if it is less than 0.8, not only is the emulsification stability poor, but the user experience is also poor (Comparative Example 7).

[0137] <Examples 6-8 and Comparative Example 8>

[0138] O / W / O type emulsion compositions with the compositions described in Table 3 below were prepared. The emulsion stability and user experience of each sample were evaluated according to the evaluation methods described above.

[0139] [Table 3]

[0140]

[0141] As shown in Table 3 above, when the ratio of (D) external phase oil to (B) lipophilic surfactant (D / B ratio) is in the range of 1 to 10, an O / W / O type emulsion composition with excellent emulsion stability and user experience is obtained (Examples 6 to 8). On the other hand, if the D / B ratio exceeds 10, sufficient emulsion stability cannot be achieved (Comparative Example 8).

[0142] <Examples 9-14>

[0143] O / W / O type emulsion compositions with the compositions described in Table 4 below were prepared. The emulsion stability and user experience of each sample were evaluated according to the evaluation methods described above.

[0144] [Table 4]

[0145]

[0146] As shown in Table 4 above, sufficient emulsification stability and usability were achieved even without the addition of (E) aqueous thickener or (F) oil thickener (Examples 11 and 12), but it was confirmed that emulsification stability could be further improved by adding them (Examples 9, 10, 13 and 14).

[0147] <Example 15 and Comparative Example 9>

[0148] O / W / O type emulsion compositions (Example 15) and W / O type emulsion compositions (Comparative Example 9) with the compositions described in Table 5 below were prepared respectively. The emulsion stability and user experience of each obtained sample were evaluated according to the evaluation method described above.

[0149] Furthermore, the effectiveness of ultraviolet protection on these samples was investigated using the following method.

[0150] <UV protection effect>

[0151] On the test plate (S plate) (5×5cm V-groove PMMA (polymethyl methacrylate) plate, SPFMASTER-PA01), at 2 mg / cm 2A small amount of absorbance was added to each sample and spread with a finger. After drying for 15 minutes, the absorbance of the formed coating was measured using a Hitachi U-3500 automatic recording spectrophotometer. The uncoated plate was used as a control. The absorbance (Abs) was calculated using the following formula. The measured values ​​from 280 nm to 320 nm were accumulated to obtain the cumulative absorbance value.

[0152] Abs = -log(T / To)

[0153] T: Transmittance of the sample; To: Transmittance without coating

[0154] The ratio of the cumulative absorbance value of Example 15 to the cumulative absorbance value of Comparative Example 9 (100%) was calculated ([cumulative absorbance value of Example 15] / [cumulative absorbance value of Comparative Example 9]×100), and the change in ultraviolet protection effect was investigated.

[0155] [Table 5]

[0156]

[0157] As shown in Table 5 above, it was confirmed that the O / W / O type emulsion composition (Example 15) had significantly better emulsion stability and user experience compared to the W / O type emulsion composition (Comparative Example 9).

[0158] In addition, it was confirmed that, despite containing the same composition and amount of (G) UV absorber, the UV protection effect of the O / W / O type emulsion composition (Example 15) was still 14% higher than that of the W / O type emulsion composition (Comparative Example 9).

[0159] <Example 16>

[0160] An O / W / O type emulsion composition having the composition described in Table 6 below was prepared (Example 16). The emulsion stability and usability of the obtained samples were evaluated according to the evaluation methods described above.

[0161] [Table 6]

[0162]

[0163] As shown in Table 6 above, it was confirmed that even when (G) UV absorber and (H) oil-soluble pharmaceutical components are incorporated into the inner oil phase, excellent emulsification stability and user experience can be achieved (Example 16).

Claims

1. An O / W / O type emulsified composition comprising: (A) HLB is a nonionic surfactant of 8-12. (B) Lipophilic surfactants with an HLB value of 7 or less. (C) Internal phase oil content, and (D) External phase oil content, (C) The internal phase oil fraction and (D) the external phase oil fraction are immiscible at temperatures ranging from 0 to 60°C. (C) The ratio of internal phase oil to (A) nonionic surfactant, i.e., the C / A ratio, is 0.8–3, and The ratio of (D) external phase oil to (B) lipophilic surfactant, i.e., the D / B ratio, is 1 to 10.

2. The O / W / O type emulsified composition according to claim 1, wherein, (A) The nonionic surfactant with an HLB of 8-12 is polyoxyethylene hydrogenated castor oil.

3. The O / W / O type emulsified composition according to claim 1, wherein, (C) The internal phase oil contains polar oil.

4. The O / W / O type emulsified composition according to claim 1, further comprising (E) an aqueous thickener.

5. The O / W / O type emulsified composition according to claim 4, wherein, (E) The aqueous thickener contains PEG-240 / HDI copolymer bis-decyltetradecyl alcohol polyether-20 ether.

6. The O / W / O type emulsified composition according to claim 1, wherein, (D) The external phase oil contains (F) oil phase thickener.

7. The O / W / O type emulsified composition according to claim 6, wherein, (F) The oil phase thickener contains distearate dimethylammonium lithium montmorillonite.

8. The O / W / O type emulsified composition according to claim 1, wherein, (D) The external phase oil does not contain cyclic silicone oil.

9. The O / W / O type emulsified composition according to claim 1, wherein, (C) The internal phase oil contains (G) ultraviolet absorbers.

10. The O / W / O type emulsified composition according to claim 1, wherein, (C) The internal phase oil contains (H) oil-soluble pharmaceutical components.

11. The O / W / O type emulsified composition according to claim 1, wherein, (C) The particle size of the emulsion particles formed by the internal phase oil fraction is less than 200 nm.

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