JP7557310B2 - Multi-layered cosmetics - Google Patents

Description

The present invention relates to a liquid multi-layered cosmetic composition that includes an emulsion layer.

Multi-layered cosmetics are liquid cosmetics consisting of two or more layers, such as an oil layer-water layer or a water layer-powder layer, and can contain oils and other ingredients, which gives them the advantage of being able to provide a variety of functions, such as a feeling of use and cleansing effects, that cannot be obtained with a single layer. However, in the case of multi-layered cosmetics consisting of an oil layer-water layer, both layers are almost transparent in appearance, and it can be difficult to tell at a glance that they are multi-layered.

In response to this, a cosmetic preparation has been proposed that clearly has a multi-layer structure, in which oil is emulsified to form emulsion particles that cause the emulsion to become cloudy, and the oil is separated into a cloudy emulsion layer that maintains this emulsified state and a clear water layer (Patent Documents 1 and 2). The multi-layer cosmetic preparations described in these patent documents contain a surfactant to form an emulsion layer.

Patent No. 3794542 JP 2002-3339 A

Generally, when temporarily emulsified oil is allowed to stand, the emulsion particles gradually coalesce over time, forming large oil droplets that collect at the top and form a partially transparent oil layer, resulting in a multi-layered cosmetic with an uneven appearance. The multi-layered cosmetic described in the above patent document has emulsion particles that are less likely to coalesce and has a certain level of stability, but further improvements, particularly improvements in the stability of emulsion particles when exposed to temperature changes, are expected.

The present invention has been made in consideration of the above circumstances, and aims to provide a multi-layered cosmetic composition that has high emulsion particle stability, particularly high temperature stability and freezing stability, and in which the emulsion layer and the aqueous layer are quickly separated.

The multi-layered cosmetic composition of the present invention comprises:
(A) one or more nonionic surfactants having a weighted average HLB value of 8.5 or more;
(B) an ionic surfactant;
(C) one or more cellulose derivatives selected from alkyl celluloses and hydroxyalkyl celluloses;
(D) an oil component;
(E) water;
It includes.

(B) The ionic surfactant is preferably an anionic surfactant or an amphoteric surfactant.

(B) It is more preferable that the ionic surfactant is an anionic surfactant.

The mass ratio of (B) ionic surfactant to (A) nonionic surfactant is preferably 0.05 to 2.5.

(A) The nonionic surfactant is preferably contained in an amount of 0.01 to 1% by mass based on the total amount of the cosmetic.

(B) The ionic surfactant is preferably contained in an amount of 0.005 to 0.5% by mass relative to the total amount of the cosmetic.

(D) The oil component may be contained in an amount of 10% by mass or more based on the total amount of the cosmetic.

The multi-layered cosmetic composition of the present invention comprises:
(A) one or more nonionic surfactants having a weighted average HLB value of 8.5 or more;
(B) an ionic surfactant;
(C) one or more cellulose derivatives selected from alkyl celluloses and hydroxyalkyl celluloses;
(D) an oil component;
(E) water;
Since it contains the above, the stability of the emulsion particles, particularly the high temperature stability and the freezing stability, can be improved, and the emulsion layer and the aqueous layer can be quickly separated.

The multi-layered cosmetic composition of the present invention will be described in detail below.
The multi-layered cosmetic composition of the present invention (hereinafter, also simply referred to as the cosmetic composition) comprises:
(A) one or more nonionic surfactants having a weighted average HLB value of 8.5 or more;
(B) an ionic surfactant;
(C) one or more cellulose derivatives selected from alkyl celluloses and hydroxyalkyl celluloses;
(D) an oil component;
(E) water;
It includes.

Each component is described in detail below. In this specification, PEG is an abbreviation for polyethylene glycol, EO is an abbreviation for ethylene oxide, PO is an abbreviation for propylene oxide, POE is an abbreviation for polyoxyethylene, and POP is an abbreviation for polyoxypropylene.

(A) One or more nonionic surfactants with a weighted average HLB value of 8.5 or more The (A) nonionic surfactant used in the present invention may be used alone or in appropriate combination of two or more, as long as the weighted average HLB (Hydrophilic-Lipophilic Balance) value is 8.5 or more. HLB is a value that generally indicates the affinity of a surfactant to water and oil, and is a parameter known as hydrophilic-lipophilic balance, and can be calculated by a known calculation method such as the Griffin method. By having a weighted average HLB value of 8.5 or more, it is possible to emulsify oil and improve the stability of emulsion particles. The weighted average HLB value is more preferably 8.5 or more and 18 or less, and even more preferably 9 or more and 14 or less. Among nonionic surfactants, it is preferable to use a hydrophilic nonionic surfactant in the multi-layered cosmetic composition of the present invention from the viewpoint of higher emulsion stability.

Specifically, examples of hydrophilic nonionic surfactants include POE-sorbitan fatty acid esters (e.g., POE-sorbitan monooleate, POE-sorbitan monostearate, POE-sorbitan tetraoleate, etc.); POE sorbitol fatty acid esters (e.g., POE-sorbitol monolaurate, POE-sorbitol monooleate, POE-sorbitol pentaoleate, POE-sorbitol monostearate, etc.); POE-glycerin fatty acid esters (e.g., POE-glycerin monostearate, POE-glycerin monoisostearate, etc.); POE-monooleates such as POE-glycerin triisostearate, etc.); polyglycerin fatty acids (e.g., polyglyceryl-10 diisostearate, etc.); POE-fatty acid esters (e.g., POE-distearate, POE-monodioleate, ethylene glycol distearate, etc.); POE-alkyl ethers (e.g., POE-lauryl ether, POE-oleyl ether, POE-stearyl ether, POE-behenyl ether, POE-2-octyldodecyl ether, POE-cholestanol ether, etc.); Pluronic type (e.g., Pluronic, etc.); POE·POP-alkyl ethers (e.g., POE·POP-cetyl ether, POE·POP-2-decyltetradecyl ether, POE·POP-monobutyl ether, POE·POP-hydrogenated lanolin, POE·POP-glycerin ether, etc.); tetraPOE·tetraPOP-ethylenediamine condensates (e.g., Tetronic, etc.); POE-castor oil and POE-hydrogenated castor oil derivatives (e.g., POE-castor oil, POE-hydrogenated castor oil, POE-hydrogenated castor oil monoisostearate, POE-hydrogenated castor oil triisostearate, stearates, POE-hydrogenated castor oil monopyroglutamic acid monoisostearate diester, POE-hydrogenated castor oil maleic acid, etc.); POE-beeswax/lanolin derivatives (for example, POE-sorbitol beeswax, etc.); alkanolamides (for example, coconut oil fatty acid diethanolamide, lauric acid monoethanolamide, fatty acid isopropanolamide, etc.); POE-propylene glycol fatty acid esters; POE-alkylamines; POE-fatty acid amides; sucrose fatty acid esters; alkylethoxydimethylamine oxide; trioleyl phosphate, etc.
More preferred examples include POE-glycerin fatty acid esters such as PEG-20 glyceryl isostearate and PEG-5 glyceryl stearate.

On the other hand, examples of lipophilic nonionic surfactants include sorbitan fatty acid esters (e.g., sorbitan monooleate, sorbitan monoisostearate, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan sesquioleate, sorbitan trioleate, diglycerol sorbitan penta-2-ethylhexyl acid, diglycerol sorbitan tetra-2-ethylhexyl acid, etc.); glycerin polyglycerin fatty acids (e.g., monocottonseed oil fatty acid glycerin, monoerucic acid glycerin, sesquioleic acid glycerin, fatty acids having a small number of EO groups added, and/or Examples of the fatty acid esters include POE-glycerin fatty acid esters (e.g., PEG-6 distearate, PEG-12 diisostearate, etc.), glycerin monostearate, α,α'-oleic acid pyroglutamic acid glycerin, monostearate malic acid, etc.) which have a large number of fatty acid residues and therefore have a low HLB; propylene glycol fatty acid esters (e.g., propylene glycol monostearate, etc.); POE-castor oil/POE-hydrogenated castor oil derivatives (e.g., PEG-10 hydrogenated castor oil, etc.) and hydrogenated castor oil derivatives which have a small number of added EO groups and therefore have a low HLB; and glycerin alkyl ethers.
More preferred examples include PEG-10 hydrogenated castor oil, PEG-6 distearate, and PEG-12 diisostearate.

(A) The amount of nonionic surfactant is not particularly limited as long as the weighted average of the HLB value is 8.5 or more, but is preferably 0.01 to 1 mass% and more preferably 0.05 to 0.5 mass% based on the total amount of the cosmetic. By setting the amount of nonionic surfactant to 0.01 mass% or more, it is possible to further improve emulsion stability, and by setting the amount to 1 mass% or less, it is possible to suppress stickiness when applied to the skin while maintaining the stability of the emulsion particles.

(B) Ionic Surfactant The (B) ionic surfactant used in the present invention includes anionic surfactants, cationic surfactants, and amphoteric surfactants. From the viewpoint of higher emulsion stability, anionic surfactants or amphoteric surfactants are more preferable.

(Anionic Surfactant)
Examples of the anionic surfactant include carboxylates such as higher fatty acid amide sulfonates, fatty acid soaps, N-acyl glutamates, and alkyl ether acetates, sulfonic acids such as α-olefin sulfonates, alkanesulfonates, and alkylbenzenesulfonic acids, sulfates such as higher alcohol sulfates, and phosphates, etc. More preferred examples include higher fatty acid amide sulfonates such as sodium stearoyl methyl taurate, sodium lauroyl methyl taurate, sodium myristoyl methyl taurate, and sodium palmitoyl methyl taurate.

(Amphoteric surfactant)
Examples of the amphoteric surfactant include carbobetaine type amphoteric surfactants such as alkylbetaines and alkylamide betaines, sulfobetaine type amphoteric surfactants such as alkylsulfobetaines and alkylhydroxysulfobetaines, phosphobetaine type amphoteric surfactants, imidazoline type amphoteric surfactants, amide amino acid salts, etc. Among the amphoteric surfactants, it is more preferable to use alkylbetaines from the viewpoint of versatility.

Examples of alkyl betaines include lauryl betaine and lauryl dimethylaminoacetate betaine. Examples of alkyl amido betaines include coconut oil fatty acid amidopropyl betaine. Examples of alkyl sulfobetaines include coconut oil fatty acid dimethyl sulfopropyl betaine. Examples of alkyl hydroxy sulfobetaines include lauryl dimethylamino hydroxy sulfobetaine. Examples of phosphobetaine type amphoteric surfactants include lauryl hydroxyphosphobetaine. Examples of imidazoline type amphoteric surfactants include coconut oil alkyl-N-hydroxyethyl imidazolinium betaine.

The (B) ionic surfactant is preferably contained in an amount of 0.005 to 0.5% by mass relative to the total amount of the cosmetic, and more preferably 0.008 to 0.2% by mass. By containing 0.005% by mass or more of the (B) ionic surfactant relative to the total amount of the cosmetic, it is possible to further improve emulsion stability, and by containing 0.5% by mass or less, it is possible to suppress stickiness when applied to the skin while maintaining the stability of the emulsion particles.

The mass ratio of (B) ionic surfactant to (A) nonionic surfactant varies depending on the type of surfactant selected, but is preferably 0.05 to 2.5, and more preferably 0.08 to 1.5. A mass ratio of (B) ionic surfactant to (A) nonionic surfactant of 0.05 or more can further improve emulsion stability, while a mass ratio of 2.5 or less can further maintain the stability of emulsion particles while suppressing stickiness when applied to the skin.

(C) One or more cellulose derivatives selected from alkyl celluloses and hydroxyalkyl celluloses The (C) one or more cellulose derivatives selected from alkyl celluloses and hydroxyalkyl celluloses used in the present invention (hereinafter also referred to simply as cellulose derivatives) are those in which the hydroxyl groups of a polymer having a cellulose skeleton are modified (substituted) with an alkyl group or a hydroxyalkyl group, and examples thereof include alkyl celluloses such as methyl cellulose, ethyl cellulose, and propyl cellulose, and hydroxyalkyl celluloses such as carboxymethyl-modified carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, and hydroxybutyl cellulose. These may also be alkali metal salts.

The content of the cellulose derivative (C) is preferably 0.01 to 0.5% by mass relative to the total amount of the cosmetic, more preferably 0.03 to 0.3% by mass, and even more preferably 0.05 to 0.25% by mass. When the content of the cellulose derivative (C) is 0.01% by mass or more relative to the total amount of the cosmetic, the separation of the emulsion layer and the aqueous layer can be made faster, and when the content is 0.5% by mass or less, the separation speed of the emulsion layer and the aqueous layer can be made faster while the stickiness when applied to the skin can be further suppressed.

(D) Oily Component The (D) oily component used in the present invention is not particularly limited, and any of liquid oils such as polar oils, silicone oils, and non-polar oils, solid oils, and semi-solid oils may be used. The multi-layered cosmetic of the present invention may contain 10% by mass or more of the oily component based on the total amount of the cosmetic. Normally, oily components act to destabilize emulsions, but the multi-layered cosmetic of the present invention has extremely high stability and can therefore contain a high amount of the oily component. The oily component may be 10 to 30% by mass, more preferably 10 to 25% by mass, and even more preferably 10 to 20% by mass, based on the total amount of the cosmetic. By making the oily component 30% by mass or less, emulsion stability can be further improved.

The polar oil is not particularly limited as long as it is generally used in cosmetics, medicines, and foods. The IOB value is not particularly limited, but is preferably 0.05 to 0.80.
The IOB value is an abbreviation for Inorganic/Organic Balance, which is a value that indicates the ratio of inorganic values to organic values, and is an index that indicates the degree of polarity of an organic compound.
IOB value is expressed as inorganic value/organic value. Here, for each of the "inorganic value" and "organic value", the "inorganic value" and "organic value" are set according to various atoms or functional groups, for example, the "organic value" for one carbon atom in a molecule is 20, and the "inorganic value" for one hydroxyl group in the molecule is 100. The IOB value of an organic compound can be calculated by integrating the "inorganic values" and "organic values" of all atoms and functional groups in the organic compound (see, for example, Fujita, "Chemical Region", Vol. 11, No. 10, pp. 719-725, 1957).

Representative examples of polar oils include ester oils and ultraviolet absorbers.
Specific examples of ester oils include tripropylene glycol dineopentanoate, isononyl isononanoate, isopropyl myristate, cetyl octanoate, octyldodecyl myristate, isopropyl palmitate, butyl stearate, hexyl laurate, myristyl myristate, decyl oleate, hexyldecyl dimethyloctanoate, cetyl lactate, myristyl lactate, lanolin acetate, isocetyl stearate, isocetyl isostearate, cholesteryl 12-hydroxystearate, cetyl ethylhexanoate, ethylene glycol di-2-ethylhexanoate, dipentaerythritol fatty acid esters, N-alkyl glycol monoisostearate, neopentyl glycol dicaprate, diisostearyl malate, glycerin di-2-heptylundecanoate, trimethylolpropane tri-2-ethylhexanoate, trimethylolpropane triisostearate, tetra ... Pentaerythrityl ethylhexanoate, triethylhexanoin (tri-2-ethylhexanoic acid glycerin), trioctanoic acid glycerin, triisopalmitic acid glycerin, triisostearate trimethylolpropane, cetyl 2-ethylhexanoate, 2-ethylhexyl palmitate, trimyristate glycerin, tri-2-heptylundecanoic acid glyceride, castor oil fatty acid methyl ester, oleyl oleate, acetoglyceryl amide, 2-heptylundecyl palmitate, diisobutyl adipate, N-lauroyl-L-glutamic acid-2-octyldodecyl ester, di-2-heptylundecyl adipate, ethyl laurate, di-2-ethylhexyl sebacate, 2-hexyldecyl myristate, 2-hexyldecyl palmitate, 2-hexyldecyl adipate, diisopropyl sebacate, 2-ethylhexyl succinate, and triethyl citrate.

Examples of UV absorbers include a wide range of highly polar oil-based UV absorbers that are generally used in cosmetics, and are not particularly limited. Examples include benzoic acid derivatives, salicylic acid derivatives, cinnamic acid derivatives, dibenzoylmethane derivatives, β,β-diphenylacrylate derivatives, benzophenone derivatives, benzylidene camphor derivatives, phenylbenzimidazole derivatives, triazine derivatives, phenylbenzotriazole derivatives, anthranil derivatives, imidazoline derivatives, benzalmalonate derivatives, and 4,4-diarylbutadiene derivatives. Specific examples and product names are listed below, but are not limited to these.

Examples of benzoic acid derivatives include ethyl para-aminobenzoate (PABA), ethyl-dihydroxypropyl PABA, ethylhexyl-dimethyl PABA (e.g., "Escarol 507"; ISP), glyceryl PABA, PEG-25-PABA (e.g., "Uvinal P25"; BASF), and diethylaminohydroxybenzoylhexyl benzoate (e.g., "Uvinal A Plus"), etc.

Examples of salicylic acid derivatives include homosalate (Eusolex HMS; Rona/EM Industries), ethylhexyl salicylate (e.g., NeoHeliopan OS; Herman & Reimer), dipropylene glycol salicylate (Dipsal; Skel), and TEA salicylate (NeoHeliopan TS; Herman & Reimer).

Examples of cinnamic acid derivatives include octyl methoxycinnamate or ethylhexyl methoxycinnamate (e.g., Parsol MCX; Hoffmann-La Roche), isopropyl methoxycinnamate, isoamyl methoxycinnamate (e.g., Neo Heliopan E1000; Herman & Reimer), cinnoxate, DEA methoxycinnamate, diisopropyl methylcinnamate, glyceryl ethylhexanoate dimethoxycinnamate, di-(2-ethylhexyl)-4'-methoxybenzalmalonate, and the like.
An example of the dibenzoylmethane derivative is 4-tert-butyl-4'-methoxydibenzoylmethane (eg, Parsol 1789).

An example of the β,β-diphenylacrylate derivative is octocrylene (eg, "Uvinal N539"; BASF).
Examples of the benzophenone derivatives include benzophenone-1 (e.g., "Uvinal 400"; BASF), benzophenone-2 (e.g., "Uvinal D50"; BASF), benzophenone-3 or oxybenzone (e.g., "Uvinal M40"; BASF), benzophenone-4 (e.g., "Uvinal MS40"; BASF), benzophenone-5, benzophenone-6 (e.g., "Helisorb 11"; Norquay), benzophenone-8 (e.g., "Spectra-Sorb UV-24"; American Cyanamid), benzophenone-9 (e.g., "Uvinal DS-49"; BASF), and benzophenone-12.

Examples of benzylidene camphor derivatives include 3-benzylidene camphor (e.g., "Mexoryl SD"; Symex), 4-methylbenzylidene camphor, benzylidene camphorsulfonic acid (e.g., "Mexoryl SL"; Symex), camphor benzalkonium methosulfate (e.g., "Mexoryl SO"; Symex), terephthalide discamphorsulfonic acid (e.g., "Mexoryl SX"; Symex), polyacrylamide methyl benzylidene camphor (e.g., "Mexoryl SW"; Symex), and the like.
Examples of phenylbenzimidazole derivatives include phenylbenzimidazole sulfonic acid (eg, "Eusolex 232"; Merck), and disodium phenyldibenzimidazole tetrasulfonate (eg, "Neo Heliopan AP"; Herman & Reimer).

Examples of triazine derivatives include anisotriazine (e.g., "Tinosorb S"; Ciba Specialty Chemicals), ethylhexyl triazone (e.g., "Uvinal T150"; BASF), diethylhexylbutamido triazone (e.g., "Uvasorb HEB"; Sigma 3V), and 2,4,6-tris(diisobutyl-4'-aminobenzalmalonate)-s-triazine.

Examples of phenylbenzotriazole derivatives include drometrizole trisiloxane (e.g., "Silatrizole"; Rhodia-Chemie), methylenebis(benzotriazolyltetramethylbutylphenol) (e.g., "Tinosorb M"; Ciba Specialty Chemicals), etc.

Examples of anthranil derivatives include menthyl anthranilate (eg, "Neo Heliopan MA"; Herman & Reimer Co.).
The imidazoline derivatives include ethylhexyldimethoxybenzylidene dioxoimidazoline propionate.

Examples of benzalmalonate derivatives include polyorganosiloxanes having benzalmalonate functional groups (for example, polysilicone-15; "Parsol SLX"; DSM Nutrition Japan).
An example of the 4,4-diarylbutadiene derivative is 1,1-dicarboxy(2,2'-dimethylpropyl)-4,4-diphenylbutadiene.
The polar oils may be used alone or in combination of two or more.

Examples of silicone oils include linear silicone oils such as dimethylpolysiloxane, methylphenylpolysiloxane, and methylhydrogenpolysiloxane, and cyclic silicone oils such as octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecamethylcyclohexasiloxane.

Non-polar oils include, for example, hydrocarbon oils such as liquid paraffin, squalane, squalene, paraffin, and isohexadecane.

Examples of solid oils include solid fats and oils such as cacao butter, coconut oil, horse oil, hardened coconut oil, palm oil, beef tallow, mutton tallow, and hardened castor oil; hydrocarbons such as paraffin wax (straight-chain hydrocarbons), microcrystalline wax (branched saturated hydrocarbons), ceresin wax, Japan wax, and Fischer-Tropsch wax; waxes such as beeswax, carnauba wax, candelilla wax, rice bran wax, gay wax, jojoba oil, rice bran wax, montan wax, kapok wax, bayberry wax, shellac wax, sugarcane wax, lanolin fatty acid isopropyl, hexyl laurate, reduced lanolin, hard lanolin, POE lanolin alcohol ether, POE lanolin alcohol acetate, POE cholesterol ether, lanolin fatty acid polyethylene glycol, and POE hydrogenated lanolin alcohol ether; and higher fatty acids such as myristic acid, palmitic acid, stearic acid, and behenic acid.

Examples of semi-solid oils include petrolatum, lanolin, shea butter, vegetable fats such as partially hydrogenated coconut oil, partially hydrogenated jojoba oil, bis-diglyceryl polyacyladipate-2, pentaerythrityl tetra (behenate/benzoate/ethylhexanoate), macadamia nut oil polyglyceryl-6-esters behenate, phytosteryl/behenyl dimer dilinoleate, dipentaerythritol hexaoxystearate, etc.

(E) Water The water may be ion-exchanged water or purified water.
The blending amount of (E) water varies depending on the product form of the multi-layered cosmetic, but is preferably 40 to 95 mass % relative to the total amount of the cosmetic, more preferably 55 to 90 mass %, and even more preferably 60 to 85 mass %.

In addition to the essential components described above, any optional components can be blended into the multi-layered cosmetic composition of the present invention, so long as the effects of the present invention are not impaired. Any optional cosmetic composition can be produced by adding the components that are usually blended into cosmetics in a conventional manner. Optional components include moisturizers, sequestering agents, antioxidants, various drugs, etc.

Examples of moisturizing agents include polyethylene glycol, propylene glycol, glycerin, 1,3-butylene glycol, xylitol, sorbitol, maltitol, chondroitin sulfate, hyaluronic acid, mucoitin sulfate, caronic acid, atelocollagen, cholesteryl-12-hydroxystearate, sodium lactate, bile salts, d,l-pyrrolidone carboxylate, short-chain soluble collagen, diglycerin (EO) PO ((ethylene oxide) propylene oxide) adduct, Rosa robur extract, Achillea millefolium extract, Melilot extract, trehalose, erythritol, POE-POP random copolymer methyl ether, etc.

Examples of sequestering agents include 1-hydroxyethane-1,1-diphosphonic acid, 1-hydroxyethane-1,1-diphosphonic acid tetrasodium salt, disodium edetate, trisodium edetate, tetrasodium edetate, sodium citrate, sodium polyphosphate, sodium metaphosphate, gluconic acid, phosphoric acid, citric acid, ascorbic acid, succinic acid, edetic acid, trisodium ethylenediaminehydroxyethyltriacetate, and the like.
Examples of vitamins include vitamins A, B1, B2, B6, C, E and derivatives thereof, pantothenic acid and derivatives thereof, biotin, and the like.

Examples of antioxidants include tocopherols, dibutylhydroxytoluene, butylhydroxyanisole, and gallic acid esters.

Examples of antioxidant aids include phosphoric acid, citric acid, ascorbic acid, maleic acid, malonic acid, succinic acid, fumaric acid, cephalin, hexametaphosphate, phytic acid, ethylenediaminetetraacetic acid, etc.

Other possible ingredients include, for example, preservatives (methylparaben, ethylparaben, butylparaben, phenoxyethanol, etc.); anti-inflammatory agents (for example, glycyrrhizinic acid derivatives, glycyrrhetinic acid derivatives, thiotaurine, hypotaurine, hinokitiol, zinc oxide, allantoin, etc.); whitening agents (for example, saxifrage extract, arbutin, tranexamic acid, L-ascorbic acid, magnesium salt of L-ascorbic acid phosphate, L-ascorbyl glucoside, etc.); cide, potassium 4-methoxysalicylate, etc.); various extracts (e.g. Phellodendron bark, Coptis japonica, Lithospermum root, Peony root, Swertia japonica, Birch, Sage, Loquat, Carrot, Aloe, Mallow, Iris, Grape, Coix seed, Loofah, Lily, Saffron, Cnidium rhizome, Angelica acutiloba, Hypericum perforatum, Ononis, Garlic, Capsicum annuum, Tangerine, Angelica acutiloba, Seaweed, etc.); activators (e.g. Royal jelly, photosensitizers, cholesterol derivatives, etc.); blood circulation promoters, etc.

The product form of the multi-layered cosmetic of the present invention is not particularly limited, but examples include cleansing cosmetics, makeup cosmetics such as foundations, makeup bases, sunscreens, skin care cosmetics, body cosmetics, antiperspirant cosmetics, hair cosmetics, etc.

The present invention will now be described in more detail with reference to examples. The present invention is not limited to the following examples. The blend amounts are in mass % unless otherwise specified.
The components shown in Tables 1 to 3 were mixed in a conventional manner to produce multi-layered cosmetic compositions. The details of the evaluation are as follows.

(Measurement of average emulsion particle size)
Immediately after production, the diameters of 100 randomly selected emulsion particles in the emulsion layer of the cosmetic were measured under a microscope, and the average value was taken as the average emulsion particle size (average particle size).

(Enlargement of emulsion particles: High temperature stability)
After storage at 45° C. for one month after production, the emulsion particles in the emulsion layer of the cosmetic were measured under a microscope in the same manner as above to determine the average emulsion particle size, and the average emulsion particle size was evaluated according to the following criteria.
A: No change in average particle size occurs after storage at 45°C for 1 month from the average particle size immediately after production. B: The rate of change in average particle size after storage at 45°C for 1 month from the average particle size immediately after production is greater than 0% and less than 150%. C: The rate of change in average particle size after storage at 45°C for 1 month from the average particle size immediately after production is greater than 150%.

(Enlargement of emulsion particles: Freezing stability)
After storage at -20°C for 3 days after production, the cosmetic was returned to room temperature and thawed. The emulsion particles in the emulsion layer of the cosmetic were measured under a microscope in the same manner as above to determine the average emulsion particle size, and the cosmetic was evaluated according to the following criteria.
A: No change in average particle size after freezing and thawing occurs from the average particle size immediately after production. B: The rate of change in average particle size after freezing and thawing from the average particle size immediately after production is greater than 0% and less than 150%. C: The rate of change in average particle size after freezing and thawing from the average particle size immediately after production is greater than 150%.

(Appearance of the formulation)
The prepared cosmetics were shaken and then left to stand for 8 hours, immediately after production, after storage for one month at 45°C, and after storage for three days at -20°C, and were evaluated according to the following criteria.
A: The upper layer is a cloudy emulsion layer, and the lower layer is a clear aqueous layer, with the two layers clearly separated. C: The entire system is cloudy without being divided into two layers.

As shown in Table 1, the multi-layered cosmetic compositions of Examples 1 and 2 (Example 2 contains 10 times the amount of nonionic surfactant (A) of Example 1) showed quick separation between the emulsion layer and the aqueous layer, and were excellent in high temperature stability and freezing stability. On the other hand, Comparative Example 1 does not contain ionic surfactant (B), and Comparative Example 2 does not contain cellulose derivative (C). In both cases, the emulsion layer and the aqueous layer were poorly separated, and in Comparative Example 1, the emulsion particles were enlarged upon freezing and thawing. Comparative Example 3 contains nonionic surfactant (A) but has a weighted average HLB of less than 8.5. In this case, the emulsion layer and the aqueous layer were quickly separated, but the emulsion particles were enlarged upon freezing and thawing. Comparative Example 4 is an example in which polyethylene glycol was blended instead of cellulose derivative (C). In this case, the emulsion layer and the aqueous layer were poorly separated, and the emulsion particles were enlarged upon freezing and thawing.

Examples 3 to 10 in Table 2 were modified in terms of the HLB of the (A) nonionic surfactant, but had superior freezing stability compared to Comparative Example 3, which had a weighted average HLB of less than 8.5.

In Table 3, Examples 11 and 12 are those in which the type of nonionic surfactant (A) was changed, Examples 13 and 14 are those in which the ionic surfactant (B) was changed to an amphoteric surfactant, Example 15 is one in which the amount of ionic surfactant (sodium stearoyl methyl taurine) (B) was increased, and Examples 16 and 17 are ones in which alcohol, which acts to lower emulsion stability, was added, but in all of these examples, the emulsion layer and the water layer separated quickly, and the high-temperature stability and freezing stability were excellent. Although not shown in the table, when the sodium carboxymethylcellulose in component (C) in Example 1 was changed to hydroxypropyl methylcellulose, the separation of the two layers was observed immediately after production, and the two layers were neatly separated.

Claims (4)

A multi-layered cosmetic composition comprising:
(A) one or more nonionic surfactants having a weighted average HLB value of 8.5 or more;
(B) an ionic surfactant;
(C) one or more cellulose derivatives selected from alkyl celluloses and hydroxyalkyl celluloses;
(D) an oil component;
(E) water;
Including,
The cosmetic contains the nonionic surfactant (A) in an amount of 0.01 to 1% by mass based on the total amount of the cosmetic,
The cosmetic contains the ionic surfactant (B) in an amount of 0.005 to 0.5% by mass relative to the total amount of the cosmetic,
The (C) cellulose derivative is contained in an amount of 0.01 to 0.5% by mass based on the total amount of the cosmetic, and
The cosmetic contains the oily component (D) in an amount of 10% by mass or more based on the total amount of the cosmetic.
Multi-layered cosmetics. The multi-layered cosmetic composition according to claim 1, wherein the ionic surfactant (B) is an anionic surfactant or an amphoteric surfactant. The multi-layered cosmetic according to claim 2, wherein the ionic surfactant (B) is an anionic surfactant. The multi-layered cosmetic composition according to claim 1, 2 or 3, wherein the mass ratio of the ionic surfactant (B) to the nonionic surfactant (A) is 0.05 to 2.5.