Foam-forming aerosol composition and aerosol product

Abstract

To provide an aerosol composition for foam formation which has good emulsion stability even if an oily component is incorporated in a large amount, good foamability and good foam stability and substantially contains no surfactant.SOLUTION: There is provided an aerosol composition for foam formation which comprises water, an oily component and a water-soluble polymer, where the water-soluble polymer includes polyvinyl alcohol, the content of the water-soluble polymer in the aerosol composition is 0.01 mass% to 2.5 mass%, the aerosol composition forms an emulsion, the average particle diameter of droplets of the emulsion is 0.5 μm to 7.0 μm and the aerosol composition substantially contains no surfactant.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to aerosol compositions for foam formation that are substantially surfactant-free. [Background technology]

[0002] Emulsions are widely used in foods, cosmetics, pharmaceuticals, etc., and it is widely known that surfactants are used as emulsifiers to stabilize the dispersion of emulsions. However, in recent years, with the growing trend toward natural products, there has been an increasing demand for emulsifier (surfactant)-free products in order to reduce the burden on the human body, such as irritation caused by surfactants, and to conserve resources.

[0003] For example, Patent Document 1 proposes a technique for adding an interfacially inactive substance as a water-soluble additive to stabilize the dispersion of a water-in-oil (W / O) emulsion, in which the dispersoid is water and the dispersion medium is oil. Patent Document 2 also discloses a composition for a screen former, which contains a water-soluble polymer and a polyhydric alcohol. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-165716 [Patent Document 2] Patent Publication No. 2021-028317 Summary of the Invention [Problem to be solved by the invention]

[0005] Meanwhile, due to diversifying customer needs in the cosmetics market, etc., there is an increasing demand for O / W emulsions containing a large amount of oily components. However, the composition of Patent Document 2 contains a small amount of oily components, making it difficult to further increase the oily component content. In addition, there is a method of using water-soluble polymers instead of surfactants to stabilize the dispersion of O / W emulsions, but it has been found that this tends to result in insufficient droplet stability and foam stability in aerosol compositions.

[0006] In view of these problems, the present disclosure provides a foam-forming aerosol composition and an aerosol product that are substantially free of surfactants and have good emulsion stability, foaming properties, and foam stability even when a large amount of oily components is contained. [Means for solving the problem]

[0007] The present disclosure provides a foam-forming aerosol composition containing water, an oily component, and a water-soluble polymer, the water-soluble polymer comprises polyvinyl alcohol; the content of the water-soluble polymer in the aerosol composition is 0.01% by mass to 2.5% by mass; The aerosol composition forms an emulsion, The emulsion droplets have an average particle size of 0.5 μm to 7.0 μm, The aerosol composition relates to a foam-forming aerosol composition that is substantially free of surfactants. [Effects of the Invention]

[0008] According to the present disclosure, there is provided a foam-forming aerosol composition that is substantially free of surfactants and that has good emulsion stability, foaming properties, and foam stability even when it contains a large amount of oily components, and An aerosol product can be provided. DETAILED DESCRIPTION OF THE INVENTION

[0009] Unless otherwise specified, the expressions "XX to YY" or "XX to YY" representing a numerical range mean a numerical range including the lower and upper limits, which are the endpoints. When a numerical range is described in stages, the upper and lower limits of each numerical range can be combined in any way. In the present disclosure, a surfactant refers to an amphiphilic substance having within its molecule a hydrophilic portion that is compatible with water and a hydrophobic portion that is compatible with hydrophobic substances (i.e., a distinct hydrophilic head group and a hydrophobic tail group), and is capable of adsorbing to the water-hydrophobic substance interface by the hydrophilic portion interacting with water and the hydrophobic portion interacting with the hydrophobic substance, thereby significantly reducing the interfacial tension at the water-hydrophobic substance interface and improving the dispersion stability of emulsions and suspensions.

[0010] Examples include sodium lauryl sulfate, stearyl trimethylammonium chloride, glyceryl stearate, polyglyceryl-10 diisostearate, polyoxyethylene coconut oil fatty acid glyceryl, sorbitan laurate, polysorbate 80, polyoxyethylene hydrogenated castor oil, polyoxyethylene lauryl ether, PEG 45 stearate, coconut oil fatty acid sodium methyl taurate, and lauryl dimethylaminoacetate betaine.

[0011] Other surfactants include the following: Anionic surfactants include fatty acid salts, alkyl phosphates, polyoxyethylene alkyl ether phosphates, alkyl sulfates, polyoxyethylene alkyl ether sulfates, alkyl ether carboxylates, alkyl sulfosuccinates, N-acylamino acid salts, N-acylmethylamino acid salts, acyl lactates, α-olefin sulfonates, α-sulfofatty acid methyl ester salts, alkyl sulfosuccinates, alkanesulfonates, alkene sulfonates, acyl isethionates, alkyl sulfate ester salts, alkylbenzene sulfonates, fatty acid alkanolamide sulfate esters, monoacylglycerin sulfate esters, alkyl phosphate ester salts, and polyoxyethylene alkyl phenyl ether phosphate salts. Cationic surfactants include fatty acid amidoamine salts, ester-containing tertiary amine salts, Arcobel-type tertiary amine salts, monoalkyl quaternary ammonium salts, dialkyl quaternary ammonium salts, trialkyl quaternary ammonium salts, alkylamine salts, monoalkyl ether-type quaternary ammonium salts, alkylpyridinium salts, alkylisoquinolium salts, benzethonium chloride, and benzalkonium-type quaternary ammonium salts.

[0012] Nonionic surfactants include polyoxyalkylene alkyl ethers, polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, polyoxyethylene castor oil, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyglycerin fatty acid esters, polyoxyethylene glycerin fatty acid esters, polyoxyethylene sorbitol fatty acid esters, polyoxyethylene hydrogenated castor oil, polyoxyethylene hydrogenated castor oil fatty acid esters, monoglycerin fatty acid esters, diglycerin fatty acid esters, sucrose fatty acid esters, polyethylene glycol fatty acid esters, alkyl polyglucosides, polyoxyalkylene sterol ethers, polyoxyethylene alkylamines, alkyl alkanolamides, alkyl glyceryl ethers, and Pluronic surfactants.

[0013] Amphoteric surfactants include glycine-type amphoteric surfactants, aminopropionic acid-type amphoteric surfactants, acetate betaine-type amphoteric surfactants, imidazoline-type amphoteric surfactants, alkyl betaines, amido betaines, sulfobetaines, alkylamine oxides, alkyldimethylamine oxides, amino acetate betaines, alkyldimethylamino acetate betaines, alkyl carbamazepines, etc. Examples of the alkyl hydroxymethyl hydroxyethyl imidazolium betaine include alkylamidopropyl betaine, alkylhydroxysulfobetaine, alkyl sulfobetaine, amidosulfobetaine, and fatty acid amidopropyl betaine. Other examples include silicone surfactants such as polyether-modified silicone, amino-modified silicone, and polyglycerin-modified silicone; fluorine-based surfactants; and natural surfactants such as lecithin, saponin, bile acid, surfactin, spiculisporic acid, agaritic acid, long-chain dicarboxylic acids, rhamnolipid, trehalose lipid, succinoyl trehalose lipid, oligosaccharide fatty acid ester, and glycosyl lipid.

[0014] The aerosol composition is substantially free of surfactants. In the present disclosure, "substantially free of surfactants" means that no surfactants are intentionally added to the aerosol composition, although it may contain trace amounts of surfactants that are inevitably mixed in during the production of the aerosol composition. For example, it may contain surfactants that are incidental to the formulated components and are present in the aerosol composition in amounts less than the amount at which their effect is exerted (so-called carryover components). For example, the content of surfactants in the aerosol composition is less than 0.10% by mass, preferably 0.05% by mass or less, more preferably 0.01% by mass or less, even more preferably 0.001% by mass or less, and particularly preferably 0% by mass.

[0015] In the present disclosure, the aerosol composition contains a water-soluble polymer. The water-soluble polymer contains polyvinyl alcohol. Polyvinyl alcohol is not considered a conventional surfactant. As mentioned above, adding a water-soluble polymer can improve the viscosity of water and suppress the floating of oil droplets (creaming) in an emulsion. However, the inventors' investigations have revealed that the addition of liquefied gas to many water-soluble polymers, such as hydroxypropyl methylcellulose, significantly reduces emulsion stability. Furthermore, when a relatively large amount of oily components is included, the foaming properties and foam stability are insufficient, and the foam tends to drip.

[0016] In contrast, it has been found that by adding polyvinyl alcohol as a water-soluble polymer to an emulsion containing an oily component and water but substantially no surfactant, the oily component can be stably dispersed even when liquefied gas is added. Unlike conventional surfactants, polyvinyl alcohol has the property of being oriented toward the oily component while being water-soluble. Therefore, the particle size of the oily component dispersion can be reduced, and stable dispersion is possible even when the oily component in the aerosol composition is high. Furthermore, it has been found that the addition of polyvinyl alcohol can form foam with good foaming properties and foam stability even when the oily component is high. The addition of polyvinyl alcohol can form foam that is resistant to foam breakage and dripping when applied to a glass surface or the like, even without the addition of a surfactant.

[0017] Each component used in the aerosol composition will be described below. The aerosol composition contains an oily component. The aerosol composition forms an emulsion. The aerosol composition is preferably an oil-in-water (O / W) emulsion in which an oil phase containing the oily component is dispersed in an aqueous phase containing water. The content of the oily component in the aerosol composition is preferably more than 1.0% by mass and not more than 35.0% by mass, more preferably more than 1.0% by mass and not more than 30.0% by mass, even more preferably more than 1.0% by mass and not more than 20.0% by mass, still more preferably 2.0 to 15.0% by mass, even more preferably 5.0 to 12.0% by mass, and particularly preferably 8.0 to 12.0% by mass. Within the above ranges, the dispersibility and stability of the droplets, as well as the foamability, are improved.

[0018] The oily component is not particularly limited, and a wide range of known components that are insoluble in water (phase-separated from water) can be used. "Water-insoluble" means that the solubility in 100 g of water at 25°C is 1.0 g or less. Specific examples include the following: Vegetable oils such as apricot kernel oil, camellia oil, argan oil, soybean oil, olive oil, castor oil, coconut oil, palm oil, palm kernel oil, sesame oil, jojoba oil, cottonseed oil, rapeseed oil, linseed oil, rosehip oil, sunflower oil, essential oils, avocado oil, almond oil, rice bran oil, safflower oil, corn oil, grapeseed oil, coconut oil, Argania spinosa kernel oil, wheat germ oil, rice germ oil, kukui nut oil, crambe abyssinica seed oil, hemp seed oil, peanut oil, camellia oil, evening primrose oil, pistachio oil, macadamia nut oil, meadowfoam oil, cocoa butter, shea butter, and Japan wax; Animal fats such as emu oil, horse oil, beef tallow, lard, mutton tallow, mink oil, egg yolk fat, carp fat, tuna fat, and menhaden fat; Hydrocarbon oils such as light isoparaffin, squalane, liquid paraffin, petrolatum, dodecane, tetradecane, ozokerite, microcrystalline wax, isoparaffin, ceresin, α-olefin oligomer, polybutene, hydrogenated polyisoparaffin, limonene, and turpentine; fatty acids (preferably having from 6 to 40 carbon atoms, more preferably from 12 to 30 carbon atoms), such as lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, isostearic acid, behenic acid, oxystearic acid, palmitoleic acid, linoleic acid, linolenic acid, ricinoleic acid, and undecylenic acid; Higher alcohols such as caproyl alcohol, caprylyl alcohol, caprylic alcohol, lauryl alcohol, isostearyl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, arachyl alcohol, behenyl alcohol, oleyl alcohol, hexyldecanol, octyldodecanol, decyltetradecanol, cholesterol, and phytosterols; Esters of straight-chain fatty acids and lower alcohols, such as isopropyl myristate, isopropyl palmitate, and ethyl oleate, Esters of straight-chain fatty acids and straight-chain higher alcohols, such as hexyl laurate, myristyl myristate, decyl oleate, and stearyl stearate, Esters of straight-chain fatty acids and branched alcohols such as octyldodecyl myristate, isostearyl palmitate, and ethylhexyl stearate; Esters of branched fatty acids and lower alcohols, such as ethyl isostearate and isopropyl isostearate; Esters of branched fatty acids and linear higher alcohols, such as cetyl ethylhexanoate and hexyl isostearate, Esters of fatty acids and polyhydric alcohols such as PG dicaprylate, triethylhexanoin, and tri(caprylic / capric acid)glyceryl, Esters of branched fatty acids and branched alcohols, such as 2-octyldodecyl neopentanoate and isostearyl isostearate, Esters of hydroxycarboxylic acids and alcohols such as lauryl lactate, tri-2-ethylhexyl citrate, trioctyldodecyl citrate, and diisostearyl malate; Ester oils such as esters of dibasic acids such as diisopropyl adipate and diethyl sebacate; Wax esters such as jojoba oil, jojoba butter, carnauba wax, candelilla wax, rice bran wax, shellac, lanolin, beeswax, montan wax, spermaceti, orange roughy oil, sugarcane wax, palm wax, insect white wax, and wool fat; Other oily ingredients include ethers of polyhydric alcohols and monohydric alcohols such as chimyl alcohol, batyl alcohol, and selachyl alcohol; batyl isostearate, batyl stearate; silicones such as alkyl-modified polysiloxane (dimethylpolysiloxane (dimethicone)), methylphenylpolysiloxane, and fluorine-modified polysiloxane; UV absorbers (diethylaminohydroxybenzoyl hexyl benzoate, methoxysilane Oil-based active ingredients such as ethylhexyl arsenate, polysilicone-15), DEET, and fragrance.

[0019] The oily component is preferably liquid at 20°C from the viewpoints of emulsion stability and ease of handling during preparation. The oily component preferably contains at least one selected from the group consisting of hydrocarbon oils, fatty acids, higher alcohols, ester oils, wax esters, silicones, vegetable oils and animal fats and oily active ingredients, more preferably contains at least one selected from the group consisting of hydrocarbon oils, ester oils, silicones, vegetable oils and oily active ingredients, even more preferably contains at least one selected from the group consisting of vegetable oils and oily active ingredients, and even more preferably contains at least one selected from the group consisting of vegetable oils and oily active ingredients. Furthermore, the oily component preferably contains at least one selected from the group consisting of olive oil, jojoba oil, rosehip oil, sunflower oil, avocado oil, almond oil, grapeseed oil, macadamia nut oil, apricot kernel oil, and soybean oil, more preferably at least one selected from the group consisting of apricot kernel oil and soybean oil, and even more preferably apricot kernel oil. Another preferred embodiment is that the oily component contains at least one selected from the group consisting of vegetable oils and fats and an oily active ingredient such as DEET. Since it is possible to include a large amount of oily component in the aerosol composition, it is easier to utilize the active ingredient.

[0020] In the aerosol composition, the average particle size of the emulsion droplets must be 0.5 μm to 7.0 μm. The inventors have discovered that by using polyvinyl alcohol as the water-soluble polymer and setting the above-mentioned specific average particle size of the droplets, emulsion stability is improved and good foam that is less likely to drip can be formed. If the average particle size of the droplets is less than 0.5 μm, the total surface area of ​​the droplets is too large, resulting in reduced emulsion stability. In addition, an excessive amount of water-soluble polymer is required to disperse the droplets. On the other hand, if the average particle size of the droplets exceeds 7.0 μm, emulsion stability is reduced.

[0021] The average particle size of the emulsion droplets is preferably 0.6 μm to 5.0 μm, more preferably 0.7 μm to 4.0 μm, even more preferably 0.9 μm to 3.0 μm, and even more preferably 1.0 μm to 2.0 μm. When the aerosol composition is an oil-in-water emulsion, the average particle size of the droplets is the average particle size of the oil droplets in the oil phase. The average particle size of the droplets can be controlled by the dispersion strength during emulsion production, the content of the water-soluble polymer, and the like.

[0022] The average particle size of emulsion droplets is measured using a laser diffraction / scattering particle size distribution analyzer (LA-960V2: Horiba, Ltd.) using a flow cell and purified water as the dispersion medium at 20°C.

[0023] The water-soluble polymer includes polyvinyl alcohol. Other known water-soluble polymers, such as those listed below, may be used in combination to the extent that the effects of the present disclosure are not impaired. These other water-soluble polymers are not considered to be conventional surfactants. Synthetic polymers such as polyvinylpyrrolidone, carboxyvinyl polymer, polyacrylic acid amide, sodium polyacrylate, polyethyleneimine, and highly polymerized polyethylene glycol; Natural polymers such as alginate, carrageenan, agar, guar gum, dextrin, locust bean gum, pectin, chitosan, xanthan gum, and cyclodextrin; Natural polymer derivatives such as ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose, stearoxyhydroxypropyl methylcellulose, carboxymethyl cellulose, and cationized cellulose. When other water-soluble polymers are used in combination, the amount of other water-soluble polymers in the aerosol composition The content is preferably 0.05% by mass or less, more preferably 0.02% by mass or less, and even more preferably 0.01% by mass or less.

[0024] The water-soluble polymer is particularly preferably polyvinyl alcohol, which has been found to be able to exhibit dispersion stability for oily components regardless of the molecular weight or degree of saponification.

[0025] The number average molecular weight Mn of the water-soluble polymer is preferably 400 or more, more preferably 500 or more, even more preferably 1000 or more, and still more preferably 2000 or more. On the other hand, the upper limit is preferably 100,000 or less, more preferably 50,000 or less, and even more preferably 40,000 or less.

[0026] When the water-soluble polymer contains polyvinyl alcohol, the degree of saponification of the polyvinyl alcohol, i.e., the ratio of hydroxyl groups to the total of hydroxyl groups and acetoxy groups in the polyvinyl alcohol [hydroxyl groups / (hydroxyl groups+acetoxy groups)×100] (mol %) is preferably 70 to 100 mol %, more preferably 80 to 98 mol %, even more preferably 82 to 95 mol %, and still more preferably 85 to 92 mol %.

[0027] The content of the water-soluble polymer in the aerosol composition is 0.01% by mass to 2.5% by mass. The content of the water-soluble polymer is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.3% by mass or more. On the other hand, the upper limit is preferably 2.0% by mass or less, more preferably 1.5% by mass or less, even more preferably 1.0% by mass or less, and even more preferably 0.7% by mass or less. With the above content, emulsion stability, foaming properties, and foam stability are improved. On the other hand, a water-soluble polymer content of 2.5% by mass or less improves the feel when used.

[0028] The content ratio (mass ratio) of the oily component to the water-soluble polymer in the air sole composition (oily component / water-soluble polymer) is preferably 5 / 1 to 120 / 1, more preferably 10 / 1 to 30 / 1, and even more preferably 15 / 1 to 25 / 1. By being in the above range, the dispersibility of the oily component becomes better.

[0029] The aerosol composition contains water. The content of water in the aerosol composition is preferably 50.0 to 97.0% by mass, more preferably 75.0 to 95.0% by mass, even more preferably 80.0 to 92.0% by mass, and still more preferably 85.0 to 91.0% by mass.

[0030] The viscosity of the aerosol composition at 25°C is preferably 0.5 mPa·s to 5.0 mPa·s, more preferably 0.7 mPa·s to 3.5 mPa·s, even more preferably 0.8 mPa·s to 2.8 mPa·s, and even more preferably 1.2 mPa·s to 2.5 mPa·s. The viscosity here is a value measured using a tuning fork vibration viscometer (RV-10000A: A&D Co., Ltd.) at an amplitude of 0.4 mm and at 25°C.

[0031] The aerosol composition may contain additives such as water-miscible (non-phase-separating) active ingredients, fragrances, antioxidants, preservatives, etc., to the extent that the above-mentioned effects are not impaired. For example, alcohol may be contained. Specific examples include the following. Lower alcohols (e.g., aliphatic monohydric alcohols having 1 to 3 carbon atoms, such as ethanol); polyhydric alcohols (e.g., glycerin, propylene glycol (PG), dipropylene glycol (DPG), butanediols such as 1,3-butanediol); pH adjusters (e.g., citric acid, lactic acid, triethanolamine, KOH, NaOH); rust inhibitors (e.g., ammonia water, ammonium benzoate, sodium nitrite); preservatives (e.g., parabens, phenols, etc.) xyethanol); urea; minerals such as calcium, iron, and sodium; pigments; dyes; anti-inflammatory agents (e.g., dipotassium glycyrrhizinate); ultraviolet absorbers (e.g., terephthalidene dicamphorsulfonic acid), etc.

[0032] Next, the aerosol product will be described. The present disclosure provides an aerosol product in which the above-described aerosol composition and a propellant are filled in an aerosol container. The aerosol container used for the aerosol product can be any of various known pressure-resistant containers. The structure for attaching the valve device can be appropriately selected depending on the type of pressure-resistant container.

[0033] Aerosol products are produced by filling an aerosol composition into an aerosol container, i.e., a pressure-resistant container equipped with an aerosol valve (spray valve). For example, an aerosol product is produced by preparing an aerosol composition and filling the resulting aerosol composition and a propellant into an aerosol container. A so-called double container may be used, in which an inner container is provided inside the pressure-resistant container to separate the propellant from the aerosol composition.

[0034] Regarding the mixing ratio between the aerosol composition and the propellant, in the case of a liquefied gas, the content of the liquefied gas is preferably 1 to 30 parts by mass, more preferably 2 to 10 parts by mass, per 100 parts by mass of the aerosol composition. The compressed gas is preferably filled so that the pressure inside the aerosol container when filled (gauge pressure) is 0.3 MPa to 1.0 MPa at 25°C, and more preferably 0.6 MPa to 0.8 MPa.

[0035] The aerosol composition is a foam-forming aerosol composition, and the aerosol product is discharged in the form of, for example, foam. To discharge the aerosol product in the form of foam, a known foam-forming spout or the like may be used. The propellant is not particularly limited, and liquefied gas or compressed gas may be used, or a combination of liquefied gas and compressed gas may be used. The aerosol product preferably contains liquefied gas. For example, the aerosol product is preferably a mixture of an aerosol composition and a liquefied gas filled in an aerosol container. Alternatively, for example, the aerosol product may be a composition for aerosol containing a propellant containing liquefied gas and an aerosol composition.

[0036] The liquefied gas is not particularly limited, and examples thereof include hydrocarbons such as dimethyl ether (DME), liquefied natural gas (LNG), liquefied petroleum gas (LPG), and isopentane; and hydrofluoroolefins such as HFO-1234ze. Liquefied petroleum gas (LPG) is preferred. The compressed gas is not particularly limited, and any known gas that can be used in aerosol products can be used. The compressed gas is preferably at least one selected from the group consisting of carbon dioxide gas, nitrogen gas, nitrous oxide gas, argon, helium, and compressed air, and more preferably at least one selected from the group consisting of carbon dioxide gas and nitrogen gas.

[0037] When the aerosol composition is an oil-in-water (O / W) emulsion, the method for producing the emulsion is not particularly limited, and known methods can be used, such as a method in which an aqueous phase and an oil phase are mixed and then emulsified using a rotary homogenizer, a high-pressure homogenizer, or an ultrasonic emulsifier. [Example]

[0038] The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples.

[0039] <Examples 1 to 25 and Comparative Examples 1 to 14> The raw materials were collected in a glass beaker according to the formulations (% by mass) shown in Tables 1 to 5 and uniformly dispersed using either of the following stock solution preparation methods 1 or 2 to prepare the aerosol compositions of Examples 1 to 25 and the aerosol compositions of Comparative Examples 1 to 14. The stock solution preparation methods employed in each of the Examples and Comparative Examples are shown in Tables 1 to 5. The average particle diameters of the emulsion droplets and the evaluation results described below are also shown in Tables 1 to 5.

[0040] (Stock solution preparation method) 1: An emulsion was prepared by stirring at 10,000 rpm for 15 minutes using a rotary homogenizer (Homomixer MARK II 2.5 type) manufactured by Primix Corporation. 2: An emulsion was prepared by irradiating the mixture with ultrasonic waves at 28.5 kHz for 5 minutes using an ultrasonic welding machine (SONOPET JII430SA) manufactured by Seidensha Kogyo Co., Ltd.

[0041] Furthermore, a pressure-resistant container equipped with an injection valve device was filled with the propellant (LPG, a mixture of dimethyl ether (DME) and LPG, or HFO-1234ze) shown in Tables 2 to 5 in an amount of parts by mass per 100 parts by mass of each of the obtained aerosol compositions, to obtain aerosol products of Examples 4 to 25 and aerosol products of Comparative Examples 4 to 14. A foam spout (02-1211-50, Japan Precision Valve Co., Ltd.) was used as the ejection mechanism. The obtained aerosol compositions and aerosol products were evaluated as described below. The results are shown in Tables 1 to 5.

[0042] [Table 1]

[0043] [Table 2] *After filling with liquefied gas, the internal pressure of the sample was adjusted to 0.6 MPa with carbon dioxide gas.

[0044] [Table 3]

[0045] [Table 4]

[0046] [Table 5]

[0047] The raw materials used in the table are as follows: (Oily ingredients) NIKKOL Apricot Kernel Oil: Apricot Kernel Oil (Nikko Chemicals Co., Ltd.) NIKKOL Olive Oil: Olive fruit oil (Nikko Chemicals Co., Ltd.) NIKKOL Jojoba Oil S: Jojoba seed oil (Nikko Chemicals Co., Ltd.) NIKKOL Grapeseed Oil: Grape seed oil (Nikko Chemicals Co., Ltd.) NIKKOL Sweet Almond Oil: Almond oil (Nikko Chemicals Co., Ltd.) NIKKOL Macadamia Nut Oil: Macadamia Seed Oil (Nikko Chemicals Co., Ltd.) NIKKOL Sunflower Oil: Sunflower seed oil (Nikko Chemicals Co., Ltd.) NIKKOL Refined Avocado Oil: Avocado Oil (Nikko Chemicals Co., Ltd.) NIKKOL Rosehip Oil: Rosa canina fruit oil (Nikko Chemicals Co., Ltd.) NIKKOL Sugar Squalane: Squalane (Nikko Chemicals Co., Ltd.) Exepar IPM: Isopropyl myristate (Kao Corporation) NIKKOL CIO: Cetyl ethylhexanoate (Nikko Chemicals Co., Ltd.) NIKKOL TOC: Tri-2-ethylhexyl citrate (Nikko Chemicals Co., Ltd.) KF-96-50cs: Dimethicone (Shin-Etsu Chemical Co., Ltd.)

[0048] (Water-soluble polymer) EG-40C: Polyvinyl alcohol (Mn approx. 39700, saponification degree 86.5 to 89.0 mol%, Mitsubishi Chemical Corporation) EG-05C: Polyvinyl alcohol (Mn approx. 10200, saponification degree 86.5 to 89.0 mol%, Mitsubishi Chemical Corporation) Sangelose 60L: Hydroxypropyl methylcellulose stearoxy ether (Daido Chemical Industry Co., Ltd.) Metrolose 60SH-06: Hydroxypropyl methylcellulose (Shin-Etsu Chemical Co., Ltd.) Pemulen TR-2: (Acrylates / C10-30 alkyl acrylate) crosspolymer (Lubrizol) InuTech SL2: Concentrated glycerin, inulin lauryl carbamate (Nihon SiberHegner Co., Ltd.) SE600: Hydroxyethyl cellulose HEC Daicel SE600 (Daicel Miraize Co., Ltd.)

[0049] (surfactant) NIKKOL TO-10V: Polysorbate 80 (Nikko Chemicals Co., Ltd.) NIKKOL Decaglyn 1-L: Polyglyceryl-10 Laurate (Nikko Chemicals Co., Ltd.) NIKKOL BB-20: Beheneth-20 (Nikko Chemicals Co., Ltd.) Triethanolamine: Triethanolamine (Ando Parachemie Co., Ltd.)

[0050] (1) Oil droplet average particle size The average particle size of the oil droplets was measured using a laser diffraction / scattering particle size distribution analyzer (LA-960V2: Horiba, Ltd.) according to the method described above, and evaluated according to the following criteria. (Evaluation criteria) A: Average particle size is 1.0 μm or more and less than 2.0 μm B+: Average particle size is 0.7 μm or more and less than 1.0 μm, average particle size is 2.0 μm or more and less than 4.0 μm B: Average particle size is 0.5 μm or more and less than 0.7 μm, and average particle size is 4.0 μm or more and 7.0 μm or less C+: Average particle size is 0.2 μm or more and less than 0.5 μm, average particle size is more than 7.0 μm and less than 10.0 μm C: Average particle size less than 0.2 μm, average particle size 10.0 μm or more

[0051] (2) Oil droplet stability Each aerosol product was stored at 45°C for two weeks, and the particle size of the emulsion droplets was measured before and after storage. avg1 is the initial average oil droplet diameter, D avg2 The average oil droplet diameter of the sample after storage for 2 weeks was calculated using the formula below and evaluated according to the following criteria.

number

[0052] (3)Stability of discharged stock solution Each aerosol product was stored at 45°C for two weeks, and after two weeks of storage, the sample contents were discharged and the foam was left to stand for a certain period of time. After the foam had disappeared, the contents were observed and visually evaluated according to the following criteria. (Evaluation criteria) A: No oil floating at all B: Almost no oil floating C: Oil floating is clearly visible

[0053] (4) Appearance of bubbles 0.5 g of foam was discharged onto a glass substrate, and the appearance of the foam was observed and visually evaluated according to the following criteria. (Evaluation criteria) A: Fine foam B: Slightly fine foam C: Coarse foam

[0054] (5) Foam stability 0.5 g of foam was discharged onto a glass substrate and stirred with a finger 10 times, and the appearance of the foam was observed and visually evaluated according to the following criteria. (Evaluation criteria) A: The bubbles remain stable and do not collapse. B: The bubbles are slightly crushed, but the foam remains. C: The bubbles collapse and most of the foam disappears.

[0055] (6) Ease of foam dripping 0.5 g of foam was dispensed onto the edge of a 10 cm x 10 cm glass substrate. The glass substrate was then placed vertically, and the time the foam was retained in the glass substrate was evaluated according to the following criteria. (Evaluation criteria) A: More than 3 minutes B+: 1 minute or more but less than 3 minutes B: 30 seconds or more but less than 1 minute C+: 15 seconds or more but less than 30 seconds C: Less than 15 seconds

[0056] <Reference examples 1~3> Aerosol compositions of Reference Examples were prepared in the same manner as in Example 1 according to the formulations (mass %) shown in Tables 6 to 8. Furthermore, 5 parts by mass of propellant (LPG) per 100 parts by mass of each of the obtained aerosol compositions was filled into a pressure-resistant container equipped with an injection valve device to obtain aerosol products of Reference Example 1 (refreshing emulsion formula), Reference Example 2 (moist emulsion formula), and Reference Example 3 (sunscreen agent). A foam spout (02-1211-50, Japan Precision Valve Co., Ltd.) was used as the ejection mechanism. The above-mentioned evaluations were carried out using the obtained aerosol compositions and aerosol products. The results are shown in Tables 6 to 8.

[0057] [Table 6]

[0058] [Table 7]

[0059] [Table 8]

Claims

1. A foam-forming aerosol composition containing water, an oily component, and a water-soluble polymer, the water-soluble polymer comprises polyvinyl alcohol; the content of the water-soluble polymer in the aerosol composition is 0.01% by mass to 2.5% by mass; The aerosol composition forms an emulsion, The emulsion droplets have an average particle size of 0.5 μm to 7.0 μm; The aerosol composition for forming foam is characterized in that it is substantially free of surfactants.

2. 2. The foam-forming aerosol composition according to claim 1, wherein the emulsion is an oil-in-water emulsion in which an oil phase containing the oily component is dispersed in an aqueous phase containing water.

3. The oil component is liquid at 20°C, 3. The foam-forming aerosol composition according to claim 1, wherein the oily component comprises at least one selected from the group consisting of hydrocarbon oils, fatty acids, higher alcohols, ester oils, wax esters, silicones, vegetable oils and fats, animal oils and fats, and oily active ingredients.

4. The foam-forming aerosol composition according to any one of claims 1 to 3, wherein the oily component comprises at least one selected from the group consisting of hydrocarbon oils, ester oils, silicones, vegetable oils and fats, and oily active ingredients.

5. The foam-forming aerosol composition according to any one of claims 1 to 4, wherein the content of the oily component in the aerosol composition is greater than 1.0% by mass and not more than 35.0% by mass.

6. An aerosol product in which an aerosol composition and a propellant are filled in an aerosol container, An aerosol product, wherein the aerosol composition is the foam-forming aerosol composition according to any one of claims 1 to 5.

7. the propellant comprises a liquefied gas; 7. The aerosol product according to claim 6, wherein the aerosol composition and the liquefied gas are mixed and filled into the aerosol container.

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