Foamable aerosol composition and aerosol product

Abstract

To provide a foamable aerosol composition having excellent emulsion stability, flowability after carbon dioxide filling, foamability and sense of use and an aerosol product using the composition.SOLUTION: There is provided a foamable aerosol composition comprising a propellant containing carbon dioxide gas and a stock solution, wherein the stock solution contains a surfactant A which is a surfactant having an HLB of 10.0 to 18.0, a surfactant B which is a surfactant having an HLB of 2.0 to 6.0, a (meth)acrylic acid polymer, an oil component, a polyhydric alcohol, a basic pH adjuster and water and the content of the (meth) acrylic acid polymer in the stock solution is 0.01 mass% to 0.25 mass%.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to a foamable aerosol composition and an aerosol product using the foamable aerosol composition. [Background technology]

[0002] Conventionally, skin cosmetics and skin cleansing compositions that are excellent in usability, such as being non-sticky and providing a moist bare skin feel, have been studied. For example, Patent Document 1 discloses a skin cosmetic that is formulated by combining an amphoteric acrylic polymer compound and / or an acidic acrylic polymer compound, which are film-forming agents, with a higher alcohol that is solid or semi-solid at room temperature. In addition, Patent Document 2 discloses a skin cleansing composition that combines two specific types of polymers, such as a carboxyvinyl polymer, a low-viscosity hydrocarbon oil, and water in a specific ratio.

[0003] By forming such skin cosmetics into a foam, not only are they not sticky, but they also do not drip easily and are easier to spread, further improving the feeling of use. Conventionally, in aerosol products that form foam, liquefied gases such as LPG and compressed gases such as carbon dioxide gas have been used as propellants and blowing agents. Liquefied gases such as LPG can form foams that have good foaming properties and are less likely to drip, but they are flammable gases and raise safety concerns. In response to this, Cited Document 3 discloses an aerosol cosmetic that contains a concentrate that contains a water-soluble thickener and water and has a pH of 7.1 to 10, and carbon dioxide gas. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2006-022026 A [Patent Document 2] JP 2015-030683 A [Patent Document 3] JP 2022-170720 A Summary of the Invention [Problem to be solved by the invention]

[0005] On the other hand, aerosol foams using compressed gases such as carbon dioxide have less foaming power, faster defoaming, and more tendency to drip than those using liquefied gas, leaving room for improvement. The shape retention of foam can be improved by increasing the viscosity of the concentrate, but when carbon dioxide gas is filled and dissolved in a concentrate with increased viscosity, the fluidity of the composition after filling with carbon dioxide gas is low, making it difficult to stably dissolve the carbon dioxide gas. If the viscosity of the concentrate is reduced to increase the fluidity, there is a problem that the foaming power is reduced and the foam quality is deteriorated.

[0006] In view of such problems, the present disclosure provides a foamable aerosol composition that is excellent in all respects of emulsion stability, fluidity after filling with carbon dioxide gas, foamability, and usability, and an aerosol product using the composition. [Means for solving the problem]

[0007] As a result of investigations aimed at solving the above-mentioned problems, the inventors have found that the above-mentioned problems can be solved by blending, in a foamable aerosol composition containing a propellant containing carbon dioxide gas and a concentrate, two types of surfactants with different HLBs, a (meth)acrylic acid-based polymer in a specific concentration range, an oily component containing a higher alcohol, a polyhydric alcohol, a basic pH adjuster, and water with the concentrate, thereby completing the present invention.

[0008] That is, the present invention includes the following aspects. [1] A foamable aerosol composition comprising a propellant containing carbon dioxide gas and a concentrate, The stock solution contains: surfactant A having an HLB value of 10.0 to 18.0; surfactant B having an HLB value of 2.0 to 6.0; a (meth)acrylic acid-based polymer; an oil component; a polyhydric alcohol; a basic pH adjuster; and water; The oil component contains a higher alcohol, The foamable aerosol composition, wherein the content of the (meth)acrylic acid-based polymer in the concentrate is 0.01% by mass to 0.25% by mass. [2] The foamable aerosol composition according to [1], wherein the oil component further contains one or more compounds selected from the group consisting of hydrocarbon compounds, ester compounds, and silicon compounds having a kinetic viscosity of 50 cs or more. [3] The foamable aerosol composition according to [1], wherein the surfactant A and the surfactant B are both nonionic surfactants. [4] The foamable aerosol composition according to [1], wherein the pH of the foamable aerosol composition is 4.0 to 5.5. [5] The foamable aerosol composition according to [1], wherein the concentrate has a viscosity of 1500 mPa·s to 30000 mPa·s at a temperature of 20°C. [6] The foamable aerosol composition according to any one of [1] to [5], which is a skin cosmetic. [7] An aerosol product in which the foamable aerosol composition is filled in an aerosol container, The foamable aerosol composition according to any one of [1] to [5], wherein the foamable aerosol composition is an aerosol product. Effect of the Invention

[0009] According to the present disclosure, it is possible to provide a foamable aerosol composition and an aerosol product using the composition, which are excellent in all of emulsion stability, fluidity after filling with carbon dioxide gas, foamability, and usability. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The description of a numerical range such as "XX to YY" or "XX to YY" means a numerical range including the lower and upper limits, unless otherwise specified. When a numerical range is described in stages, the upper and lower limits of each numerical range can be arbitrarily combined.

[0011] [Foamable aerosol composition] A foamable aerosol composition according to one embodiment of the present invention (hereinafter, also simply referred to as "foamable aerosol composition") is a foamable aerosol composition containing a propellant containing carbon dioxide gas and a concentrate. The concentrate contains surfactant A, which is a surfactant having an HLB of 10.0 to 18.0, surfactant B, which is a surfactant having an HLB of 2.0 to 6.0, a (meth)acrylic acid-based polymer, an oil component, a polyhydric alcohol, a basic pH adjuster, and water. The oil component further contains a higher alcohol, and the content of the (meth)acrylic acid-based polymer in the concentrate is 0.01% by mass to 0.25% by mass. Such a foamable aerosol composition is excellent in all respects of emulsion stability, fluidity after filling with carbon dioxide gas, foaming property, and usability. Each component contained in the foamable aerosol composition will be described below.

[0012] (Surfactant) The concentrate contained in the foamable aerosol composition contains surfactant A, which is a surfactant having an HLB of 10.0 to 18.0 (preferably 12.0 to 16.5), and surfactant B, which is a surfactant having an HLB of 2.0 to 6.0 (preferably 2.5 to 5.0, more preferably 2.7 to 4.5, and even more preferably 2.7 to 3.5).

[0013] By using the above two types of surfactant A and surfactant B in combination, good emulsion stability can be achieved. The reason for this is that two specific surfactants with different HLB values ​​are combined. The present inventors believe that this is because the surfactant density lining the oil-water interfacial film increases as a result.

[0014] The content of surfactant A in the stock solution is preferably 0.10% by mass to 5.00% by mass, more preferably 0.30% by mass to 3.00% by mass, even more preferably 0.50% by mass to 2.50% by mass, and even more preferably 0.70% by mass to 2.00% by mass. The content of surfactant B in the stock solution is preferably 0.10% by mass to 5.00% by mass, more preferably 0.20% by mass to 2.50% by mass, and even more preferably 0.25% by mass to 1.80% by mass. By having the contents of surfactant A and surfactant B within the above ranges, the emulsion stability can be further improved.

[0015] At least one of the surfactant A and the surfactant B is preferably a nonionic surfactant, and more preferably both are nonionic surfactants.

[0016] Here, the HLB value of the surfactant is calculated by the following Griffin method: In the following formula (1), "sum of formula weights of hydrophilic groups / molecular weight" is the mass % of the hydrophilic groups. (1) Griffin method: HLB value = 20 x (sum of hydrophilic group formula weights / molecular weight)

[0017] The surfactant A may be, for example, at least one selected from the following: Polyoxyethylene hydrogenated castor oils such as PEG-40 hydrogenated castor oil, PEG-50 hydrogenated castor oil, PEG-60 hydrogenated castor oil, PEG-70 hydrogenated castor oil, PEG-80 hydrogenated castor oil, and PEG-100 hydrogenated castor oil; Beheneth-20, Beheneth-30, Ceteth-10, Ceteth-15, Ceteth-20, Laureth-9, Oleth-10, Oleth-15, Oleth-20, Oleth-20, Oleth-30, Oleth-40, Oleth-50, Oleth-60, Oleth-70, Oleth-80, Oleth-9, Oleth-10, Oleth-20, Oleth-15, Oleth-20, Oleth-20, Oleth-30, Oleth-40, Oleth-50, Oleth-60, Oleth-70, Oleth-80, Oleth-9, Oleth-10, Oleth-15, Oleth-20, Oleth-20, Oleth-30, Oleth-4 ...30, Oleth-40, Oleth-15, Oleth-20, Oleth-20, Oleth-30, Oleth-30, Oleth-40, Oleth-15, Oleth-20, Oleth-30, Oleth-40, Oleth-15, Oleth-20, Oleth- polyoxyethylene alkyl ethers such as (C12-14) Pareth-50, (C12-14) Pareth-7, (C12-14) Pareth-9, and (C12-14) Pareth-12; polyoxyethylene alkyl ethers such as polyglyceryl-6 laurate, polyglyceryl-10 laurate, polyglyceryl-10 myristate, polyglyceryl-10 palmitate, polyglyceryl-10 stearate, polyglyceryl isostearate, polyglycerin fatty acid esters such as polyglyceryl-10, polyglyceryl-10 oleate, and polyglyceryl-10 linoleate; polyoxyethylene sorbitan fatty acid esters such as polysorbate 40, polysorbate 60, and polysorbate 80; polyoxyethylene sorbitan fatty acid esters such as sorbeth-6 laurate, sorbeth-60 tetrastearate, sorbeth-40 tetraoleate, and sorbeth-60 tetraoleate; and polyoxyethylene glyceryl isostearates such as PEG-25 glyceryl isostearate, PEG-30 glyceryl isostearate, PEG-40 glyceryl isostearate, PEG-50 glyceryl isostearate, and PEG-60 glyceryl isostearate.

[0018] The surfactant B may be, for example, at least one selected from the following: Sorbitan fatty acid esters such as sorbitan monooleate, sorbitan dioleate, sorbitan trioleate, sorbitan sesquioleate, sorbitan monostearate, sorbitan distearate, sorbitan tristearate, sorbitan isostearate, sorbitan sesquistearate, sorbitan monocaprate, sorbitan monolaurate, and sorbitan monopalmitate; glycerin fatty acid esters such as glyceryl myristate, glyceryl stearate, glyceryl isostearate, and glyceryl oleate; and polyglyceryl-2 stearate, polyglyceryl-2 oleate, polyglyceryl-2 isostearate, polyglyceryl-4 stearate, polyglyceryl-4 oleate, polyglyceryl-6 tristearate, polyglyceryl-10 pentastearate, polyglyceryl-10 pentaisostearate, and polyglyceryl-10 pentaoleate. Polyglycerol fatty acid esters such as glyceryl-10.

[0019] The surfactant A is preferably at least one selected from the group consisting of polyoxyethylene alkyl ethers, polyglycerin fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbit fatty acid esters, and polyoxyethylene glyceryl isostearate, and more preferably at least one selected from the group consisting of beheneth-20 (HLB: 16.5), polyglyceryl-10 laurate (HLB: 15.5), polysorbate 80 (HLB: 15.0), sorbeth-60 tetraoleate (HLB: 14.0), polyglyceryl-10 oleate (HLB: 12.0), and PEG-60 glyceryl isostearate (HLB: 16.0).

[0020] The surfactant B is preferably a glycerin fatty acid ester, more preferably glyceryl stearate (HLB: 3.0).

[0021] ((Meth)acrylic acid-based polymer) The concentrate contained in the foamable aerosol composition contains a (meth)acrylic acid-based polymer. In this specification, "(meth)acrylic" means "acrylic" or "methacrylic".

[0022] By including a (meth)acrylic acid-based polymer in the concentrate, good fluidity and foamability after carbon dioxide gas filling can be achieved. The present inventors consider the reason for this to be as follows. The (meth)acrylic acid-based polymer acts as a thickener that increases the viscosity of the concentrate, and can thicken the concentrate to a specific viscosity range by neutralizing it with a basic pH adjuster described below. When carbon dioxide gas is added to the concentrate, the pH decreases due to the carbon dioxide, and the viscosity decreases, and the fluidity of the composition increases, allowing the carbon dioxide gas to dissolve easily. When the composition is filled into an aerosol container and sprayed, the carbon dioxide gas evaporates, the pH of the composition increases, and the composition thickens again, allowing the composition to exhibit high foaming properties.

[0023] The content of the (meth)acrylic acid-based polymer in the raw solution is 0.01% by mass to 0.25% by mass, preferably 0.02% by mass to 0.20% by mass, and more preferably 0.03% by mass to 0.15% by mass. By having the content of the (meth)acrylic acid-based polymer within the above range, it is possible to further improve the fluidity and foamability after filling with carbon dioxide gas.

[0024] The (meth)acrylic acid-based polymer may be, for example, at least one selected from the following: Polymers containing monomer units of acryloyldimethyltaurate, such as polyacrylic acid and its salts, carboxyvinyl polymers, alkyl-modified carboxyvinyl polymers, methacrylic acid polymers, alkyl-modified methacrylic acid polymers, acrylates copolymers, copolymers of acrylic acid and acryloyldimethyltaurate (e.g., sodium acrylate-sodium acryloyldimethyltaurate copolymer), copolymers of hydroxyethyl acrylate and acryloyldimethyltaurate, and copolymers of acrylic acid, acrylates, acrylamide and acryloyldimethyltaurate.

[0025] The (meth)acrylic acid-based polymer is preferably at least one selected from the group consisting of carboxyvinyl polymers and alkyl-modified carboxyvinyl polymers. Carboxyvinyl polymers are also called carbomers. Examples of alkyl-modified carboxyvinyl polymers include (acrylates / alkyl acrylate (C10-30)) crosspolymers.

[0026] (Oily ingredients) The concentrate contained in the foamable aerosol composition contains an oily component. The oily component may be insoluble in water (phase-separated from water), but preferably contains a higher alcohol and one or more selected from a hydrocarbon compound, an ester compound, and a silicon compound having a kinetic viscosity of 50cs or more, and more preferably contains all of a hydrocarbon compound, an ester compound, and a silicon compound having a kinetic viscosity of 50cs or more. By containing a higher alcohol, the concentrate can achieve a good feeling of use, and by further containing a hydrocarbon compound, an ester compound, and a specific silicon compound (hereinafter, together with the higher alcohol, also referred to as a "specific oily component"), the feeling of use can be further improved. In addition, "insoluble in water" refers to, for example, a solubility of 100g in water at 25°C of 1.0g or less.

[0027] The content of the oily component in the concentrate is preferably 0.50% by mass to 50.00% by mass, more preferably 1.00% by mass to 40.00% by mass, and even more preferably 2.00% by mass to 30.00% by mass. By having the content of the oily component within the above range, the feeling of use can be further improved.

[0028] The higher alcohol contained in the oil component may be, for example, at least one selected from the following: Caproyl alcohol, caprylyl alcohol, capryl alcohol, lauryl alcohol, isostearyl alcohol, myristyl alcohol, cetanol, stearyl alcohol, arachyl alcohol, behenyl alcohol, oleyl alcohol, hexyldecanol, octyldodecanol, decyltetradecanol, cholesterol, and phytosterols. The content of the higher alcohol in the concentrate is preferably 0.07% by mass to 7.50% by mass, more preferably 0.15% by mass to 6.00% by mass, and further preferably 0.30% by mass to 4.50% by mass.

[0029] Examples of the hydrocarbon compound contained in the oil component include at least one selected from the following: Light isoparaffin, squalane, liquid paraffin, petrolatum, dodecane, tetradecane, ozokerite, microcrystalline wax, isoparaffin, ceresin, α-olefin oligomer, polybutene, hydrogenated polyisoparaffin, limonene, turpentine, and mineral oil. The content of the hydrocarbon compound in the raw solution is preferably 0.25% by mass to 25.00% by mass, more preferably 0.50% by mass to 20.00% by mass, and further preferably 1.00% by mass to 15.00% by mass.

[0030] Examples of the ester compound contained in the oil component include at least one selected from the following: Isopropyl myristate, butyl myristate, isocetyl myristate, octyldodecyl myristate, butyl stearate, ethylhexyl stearate, isopropyl isostearate, isopropyl palmitate, ethylhexyl palmitate, ethyl linoleate, butyloctyl salicylate, cetyl ethylhexanoate, ethyl oleate (ethyl oleate), hexyl laurate, myristyl myristate, decyl oleate, stearyl stearate, palmitic fatty acid esters such as isostearyl acid, ethyl isostearate, hexyl isostearate, 2-octyldodecyl neopentanoate, and isostearyl isostearate; polyhydric alcohol fatty acid esters such as triethylhexanoin, propylene glycol monocaprylate, propylene glycol dicaprylate, trimethylolpropane triethylhexanoate, trimethylolpropane triisostearate, and tri(caprylic acid / capric acid)glyceryl; lauryl lactate, citric acid Esters of hydroxycarboxylic acids and alcohols, such as tri-2-ethylhexyl, trioctyldodecyl citrate, and diisostearyl malate; and polybasic acid esters, such as diisopropyl adipate, diisopropyl sebacate, and diethyl sebacate. The content of the ester compound in the concentrate is preferably 0.07% by mass to 7.50% by mass, more preferably 0.15% by mass to 6.00% by mass, and further preferably 0.30% by mass to 4.50% by mass.

[0031] Examples of the silicon compound contained in the oil component include at least one selected from the following: Alkyl-modified polysiloxane (dimethylpolysiloxane (dimethicone)), methylphenylpolysiloxane, and fluorine-modified polysiloxane. The silicone compound contained in the oil component has a kinetic viscosity of preferably 50cs or more, more preferably 100cs or more, and even more preferably 200cs or more.The upper limit of the kinetic viscosity is not particularly limited, but is usually 100000cs or less, preferably 10000cs or less.By having the kinetic viscosity of the silicone compound within the above range, the volatility of the silicone compound is reduced, and the feeling of use can be further improved. The content of the silicon compound in the original solution is preferably 0.05% by mass to 5.00% by mass, more preferably 0.10% by mass to 4.00% by mass, and further preferably 0.20% by mass to 3.00% by mass.

[0032] Examples of oil components other than the specific oil components include the following: vegetable oils and fats 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, meadowhoo oil, cocoa butter, shea butter, and Japan wax; Animal fats and oils such as emu oil, horse fat, beef tallow, lard, mutton tallow, mink oil, egg yolk fat, carp fat, tuna fat, and menhaden fat; Fatty acids (preferably having 6 to 40 carbon atoms, more preferably having 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; Wax esters such as jojoba oil, jojoba butter, carnauba wax, candelilla wax, rice bran wax, shellac, lanolin, beeswax, montan wax, spermaceti, orange roughy oil, sugar cane wax, palm wax, insect wax, and wool wax; Ethers of polyhydric alcohols and monohydric alcohols, such as chimyl alcohol, batyl alcohol, and selachyl alcohol; Batyl isostearate, batyl stearate; Examples of active ingredients include oil-based ingredients such as UV absorbers (diethylaminohydroxybenzoylhexyl benzoate, ethylhexyl methoxycinnamate, octocrylene, t-butyl methoxybenzoylmethane, ethylhexyl salicylate, polysilicone-15), DEET, icaridin, and fragrances. These oil components may be used alone or in combination of two or more in addition to the specific oil component.

[0033] The oil component is preferably liquid at 20°C from the viewpoints of emulsion stability and ease of handling during preparation.

[0034] (Polyhydric alcohol) The concentrate contained in the foamable aerosol composition contains a polyhydric alcohol. When the concentrate contains a polyhydric alcohol, a good feeling when used can be achieved.

[0035] The content of the polyhydric alcohol in the concentrate is preferably 0.50% by mass to 30.00% by mass, more preferably 1.00% by mass to 25.00% by mass, and even more preferably 2.00% by mass to 20.00% by mass. By having the content of the polyhydric alcohol within the above range, the feeling during use can be further improved.

[0036] The polyhydric alcohol may be, for example, at least one selected from the following: Glycerin, diglycerin, propanediol, propylene glycol (PG), dipropylene glycol (DPG), and butylene glycols such as 1,3-butylene glycol. The polyhydric alcohol is preferably at least one selected from the group consisting of glycerin and butylene glycol, and more preferably at least one selected from the group consisting of glycerin and 1,3-butylene glycol.

[0037] (Basic pH adjuster) The concentrate contained in the foamable aerosol composition contains a basic pH adjuster. By including the basic pH adjuster in the concentrate, the above-mentioned (meth)acrylic acid-based polymer can be neutralized to thicken the concentrate, and good fluidity and foamability can be achieved after filling with carbon dioxide gas. In this specification, "basic" means that the pH of the aqueous solution when dissolved in water is more than 7.

[0038] The mass ratio of the content of the basic pH adjuster to the content of the (meth)acrylic acid-based polymer in the concentrate is preferably 0.05 to 1.25, more preferably 0.10 to 0.70, and even more preferably 0.15 to 0.40. It is preferable to adjust the content of the basic pH adjuster so that the viscosity of the concentrate, the pH of the concentrate, and the pH immediately after spraying of the foamable aerosol composition are each within the range described below. By adjusting the content of the basic pH adjuster as described above, the fluidity and foamability after filling with carbon dioxide gas can be further improved.

[0039] The basic pH adjuster is not particularly limited as long as it can neutralize the (meth)acrylic acid-based polymer, and examples thereof include triethanolamine, KOH, and NaOH.

[0040] (water) The concentrate contained in the foamable aerosol composition contains water. The content of water in the concentrate is not particularly limited, but is preferably 50.00% by mass to 99.85% by mass, more preferably 60.00% by mass to 99.50% by mass, and further preferably 70.00% by mass to 99.30% by mass.

[0041] (Other additives) The concentrate contained in the foaming aerosol composition may contain additives such as water-miscible (non-phase-separating) active ingredients, fragrances, antioxidants, preservatives, acidic pH adjusters, thickeners, moisturizers, bactericides, skin protectants (amino acids), vitamins, various extracts, deodorants, coolants, ultraviolet absorbers, ultraviolet scattering agents, pest repellent components, and others, to the extent that the above 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); acidic pH adjusters (e.g., citric acid, lactic acid); rust inhibitors (e.g., ammonia water, ammonium benzoate, sodium nitrite); preservatives (e.g., parabens, phenoxyethanol, methyl paraoxybenzoate); urea; minerals such as calcium, iron, sodium, etc.; pigments; colorants; anti-inflammatory agents (e.g., dipotassium glycyrrhizinate); ultraviolet absorbers (e.g., terephthalidenedicamphorsulfonic acid), etc.

[0042] (viscosity of original solution) The viscosity of the concentrate contained in the foamable aerosol composition at a temperature of 20° C. is preferably 1500 mPa·s to 30000 mPa·s, and more preferably 2000 mPa·s to 20000 mPa·s. The viscosity here is measured using a B-type viscometer (TVB-10: Toki Sangyo Co., Ltd.) with a No. M3 rotor at a rotation speed of 12 rpm for a measurement time of 1 minute, and when the measured value exceeds the upper measurement limit (10000 mPa·s), the value is measured using a No. M4 rotor at a rotation speed of 12 rpm for a measurement time of 1 minute. By having the viscosity of the concentrate at 20° C. be within the above range, the fluidity and foaming properties after filling with carbon dioxide gas can be further improved.

[0043] (pH of stock solution) The pH of the concentrate contained in the foamable aerosol composition is preferably 5.0 to 7.0, more preferably 5.3 to 6.9, and even more preferably 5.5 to 6.8. The pH here is a value measured by adjusting the temperature of the concentrate to 20°C with a pH meter (HM-30R: Toa Denpa Kogyo Co., Ltd.). By having the pH of the concentrate within the above range, the fluidity and foaming properties after carbon dioxide gas filling can be further improved.

[0044] (pH of foamable aerosol composition) The pH of the foamable aerosol composition is preferably 4.0 to 5.5, more preferably 4.3 to 5.3, and further preferably 4.5 to 5.2. The pH here can be measured as follows. When the foamable aerosol composition is used in an aerosol product, the temperature of the aerosol product is adjusted to 25°C, and the foamable aerosol composition is sprayed from the aerosol product into a 100 mL glass container in a 25°C normal pressure environment, and then measurement is immediately started using a pH meter (HM-30R: Toa Denpa Kogyo Co., Ltd.) and the measured value 1 minute after spraying is adopted. When the pH of the foamable aerosol composition is within the above range, the fluidity and foaming property after filling with carbon dioxide gas can be further improved.

[0045] (mass ratio of concentrate to carbon dioxide) The mass ratio of the concentrate to carbon dioxide gas (concentrate:carbon dioxide gas) in the foamable aerosol composition is preferably 90.0:10.0 to 99.5:0.5, more preferably 93.0:7.0 to 99.0:1.0, and even more preferably 95.0:5.0 to 98.5:1.5.

[0046] (Method for producing foamable aerosol composition) The method for producing the foamable aerosol composition is not particularly limited, and a known method can be used. For example, a method can be mentioned in which surfactant A, surfactant B, (meth)acrylic acid-based polymer, oily component, polyhydric alcohol, basic pH adjuster, water, and other components as necessary are mixed in any ratio, emulsified using a rotary homogenizer, high-pressure homogenizer, ultrasonic emulsifier, or the like to form a stock solution, and a propellant containing carbon dioxide gas is further filled into the stock solution.

[0047] The foamable aerosol composition can be used for any purpose, including personal care products, household products, industrial products, etc. The foamable aerosol composition is preferably a skin cosmetic, more preferably a skin cosmetic for femcare. In particular, when used as a skin cosmetic for femcare, the foam is less likely to drip, is easy to spread, is not sticky, and provides a sufficient moisturizing feeling.

[0048] (Aerosol products) An aerosol product according to one embodiment of the present invention (hereinafter, also simply referred to as "aerosol product") is an aerosol product in which the foamable aerosol composition is filled in an aerosol container. The aerosol container used for the aerosol product may be any of various known pressure-resistant containers. In addition, the structure for mounting the valve device may be appropriately selected depending on the type of pressure-resistant container.

[0049] The aerosol product is produced by filling the foamable aerosol composition into an aerosol container, i.e., a pressure-resistant container equipped with an aerosol valve (spray valve). For example, a concentrate is prepared, and the concentrate and a propellant containing carbon dioxide gas are filled into an aerosol container to produce the aerosol product. A so-called double container may be used in which an inner container is further provided inside the pressure-resistant container to isolate the propellant and the emulsion composition.

[0050] The foamable aerosol composition is filled into an aerosol container so that the pressure inside the container (gauge pressure) at 25°C is preferably 0.1 MPa to 1.0 MPa, and more preferably 0.2 MPa to 0.9 MPa.

[0051] The form of the aerosol product to be sprayed is not particularly limited, but is preferably foam-like. The spray mechanism of the aerosol product is also not particularly limited, and any known actuator capable of spraying the product in foam form may be used. EXAMPLES

[0052] The present invention will be described in detail below with reference to examples, but the present invention is not limited to the embodiments of the following examples.

[0053] <Examples 1 to 22 and Comparative Examples 1 to 9> A total of 100 g of each raw material was collected and mixed in a glass beaker according to the formulation (mass %) shown in Tables 1 to 6, and then emulsified using a rotor homogenizer (Homomixer MARK II 2.5 type, manufactured by Primix Corporation) to obtain the stock solutions of Examples 1 to 22 and Comparative Examples 1 to 9.

[0054] The obtained concentrate and propellant (carbon dioxide gas) were then filled into a pressure-resistant container to obtain an aerosol product. The spray mechanism used was "FD129W"3" (Mitani Valve Co., Ltd.). Furthermore, the obtained concentrate and aerosol products were used for the evaluations described below. The results are shown in Tables 1 to 6.

[0055] (1) Viscosity measurement of the original solution The obtained stock solution was adjusted to a temperature of 20°C, and the viscosity (mPa s) was measured using a Brookfield viscometer (TVB-10: Toki Sangyo Co., Ltd.) with a rotor of No. M3 or No. M4, a rotation speed of 12 rpm, and a measurement time of 1 minute.

[0056] (2) pH measurement of the original solution The temperature of the obtained stock solution was adjusted to 20° C., and the pH was measured using a pH meter (HM-30R: Toa Denpa Kogyo Co., Ltd.).

[0057] (3) pH measurement of foamable aerosol composition The temperature of the obtained aerosol product was adjusted to 25°C, and the foamable aerosol composition was sprayed from the aerosol product into a 100 mL glass container in a 25°C normal pressure environment. Then, measurement was immediately started using a pH meter (HM-30R: Toa Denpa Kogyo Co., Ltd.), and the measured value 1 minute after spraying was recorded.

[0058] (4) Emulsion stability evaluation of the original solution The obtained stock solution was stored in a glass bottle at 40° C. for one week, and the appearance of the stock solution was visually observed and evaluated according to the following evaluation criteria.

[0059] [Evaluation Criteria] 3: Does not separate. 2: Slight separation. 1: Separate.

[0060] (5) Usability evaluation The obtained aerosol product was adjusted to a temperature of 25° C., and about 1 g of the foamable aerosol composition was sprayed and applied to the forearm of each panelist. The sensation of use was evaluated according to the following evaluation points, and the arithmetic average of the 10 panelists was calculated and evaluated according to the following evaluation criteria.

[0061] [Evaluation points] 5 points: Does not feel sticky. 4 points: Feels slightly sticky. 3 points: Feels sticky. 2 points: Feels somewhat sticky. 1 point: Very sticky feeling. [Evaluation Criteria] 4: The arithmetic mean of the evaluation score is between 4.0 and 5.0 points. 3: The arithmetic mean of the evaluation score is 3.0 or more but less than 4.0 points. 2: The arithmetic mean of the evaluation score is 2.0 or more but less than 3.0 points. 1: The arithmetic mean of the evaluation scores is 1.0 or more but less than 2.0 points.

[0062] (6) Foamability evaluation The temperature of the obtained aerosol product was adjusted to 25° C., and the foamable aerosol composition was sprayed onto a plastic plate for 1 second. The sprayed foam was visually observed and evaluated according to the following evaluation criteria.

[0063] [Evaluation Criteria] 3: Three-dimensional bubbles were formed. 2: Planar bubbles were formed. 1: Almost no foam was formed and it quickly became liquid.

[0064] (7) Fluidity evaluation after gas filling The obtained concentrate and a propellant (carbon dioxide gas) were charged into a pressure-resistant container and then shaken. The movement of the foamable aerosol composition was visually observed and evaluated according to the following evaluation criteria.

[0065] [Evaluation Criteria] 2: The mixture was fluid and the gas dissolved immediately. 1: No liquidity at all.

[0066] [Table 1]

[0067] [Table 2]

[0068] [Table 3]

[0069] [Table 4]

[0070] [Table 5]

[0071] [Table 6]

[0072] In the table, the raw materials used are as follows:

[0073] (Surfactant A) Polysorbate 80: NIKKOL TO-10V (Nikko Chemicals Co., Ltd.) Beheneth-20: NIKKOL BB-20 (Nikko Chemicals Co., Ltd.) Polyglyceryl-10 laurate: NIKKOL DECAGLYN 1-L (Nikko Chemicals Co., Ltd.) Sorbeth-60 tetraoleate: NIKKOL GO-460V (Nikko Chemicals Co., Ltd.) company) Polyglyceryl-10 oleate: NIKKOL Decaglyn 1-OV (Nikko Chemicals Co., Ltd.) PEG-60 glyceryl isostearate: EMALEX GWIS-160 (Nihon Emulsion Co., Ltd.)

[0074] (Surfactant B) Glyceryl stearate: NIKKOL MGS-BV2 (Nikko Chemicals Co., Ltd.)

[0075] (Silicon compounds) Dimethicone 350cs:DOWSIL TM SH 200C Fluid 350c s(Dow Chemical Japan Co., Ltd. / Dow Toray Co., Ltd.) Dimethicone 1000cs:DOWSIL TM SH 200C Fluid 100 0cs (Dow Chemical Japan Co., Ltd. / Dow Toray Co., Ltd.)

[0076] (Higher alcohol) Behenyl alcohol: Kalcol 220-80 (Kao Corporation) Stearyl alcohol: Kalcol 8098 (Kao Corporation)

[0077] (Hydrocarbon compounds) Mineral oil: CARNATION (sonneborn) Squalane: Sugar squalane (Nikko Chemicals Co., Ltd.)

[0078] (Ester compounds) Isopropyl palmitate: Exepar IPP (Kao Corporation) Ethylhexyl palmitate: M Fine Oil EHP (Miyoshi Oil Co., Ltd.)

[0079] (Polyhydric alcohol) Glycerin: Cosmetic concentrated glycerin (Kao Corporation) Butylene glycol: 1,3-butylene glycol-P (KH Neochem Co., Ltd.)

[0080] (Basic pH adjuster) Potassium hydroxide: Japanese Pharmacopoeia Potassium hydroxide (Kosakai Pharmaceutical Co., Ltd.)

[0081] ((Meth)acrylic acid-based polymer) (Acrylates / C10-30 alkyl acrylate) crosspolymer: Pemulen TM TR-2 Polymeric Emulsifier (Lubrizol Japan, Ltd.) Carbomer: Carbopol® Ultrez 10 Polymer (Lubrizol Corporation)

[0082] (Thickener) Xanthan gum: Echo Gum T (MP Gokyo Food & Chemical Co., Ltd.) Stearoxyhydroxypropyl methylcellulose: Sangelose 60L (Daido Chemical Industry Co., Ltd.) Hydroxyethyl cellulose: HEC Daicel SE600 (Daicel Miraize Co., Ltd.)

[0083] (Preservatives) Phenoxyethanol: Phenoxyethanol-SP (Yokkaichi Chemical Co., Ltd.)

[0084] (base material) Water: Purified water (Toyo Aerosol Industry Co., Ltd.)

Claims

1. A foamable aerosol composition comprising a propellant containing carbon dioxide gas and a concentrate, The stock solution contains: surfactant A having an HLB of 10.0 to 18.0; surfactant B having an HLB of 2.0 to 6.0; a (meth)acrylic acid-based polymer; an oil component; a polyhydric alcohol; a basic pH adjuster; and water; The oil component contains a higher alcohol, The foamable aerosol composition has a (meth)acrylic acid-based polymer content of 0.01% by mass to 0.25% by mass in the concentrate.

2. 2. The foamable aerosol composition according to claim 1, wherein the oil component further comprises one or more compounds selected from the group consisting of hydrocarbon compounds, ester compounds, and silicon compounds having a kinetic viscosity of 50 cs or more.

3. 2. The foamable aerosol composition according to claim 1, wherein both of said surfactant A and said surfactant B are nonionic surfactants.

4. 2. The foamable aerosol composition according to claim 1, wherein the pH of the foamable aerosol composition is from 4.0 to 5.

5.

5. 2. The foamable aerosol composition according to claim 1, wherein the concentrate has a viscosity of 1,500 mPa·s to 30,000 mPa·s at a temperature of 20° C.

6. The foamable aerosol composition according to any one of claims 1 to 5, which is a skin cosmetic.

7. An aerosol product in which a foamable aerosol composition is filled in an aerosol container, An aerosol product, wherein the foamable aerosol composition is the foamable aerosol composition according to any one of claims 1 to 5.

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