JP2020050628A - Antiseptic emulsion composition and antiseptic method - Google Patents

Abstract

To provide a novel antiseptic technique for an emulsion composition substantially free from a surfactant.SOLUTION: An emulsion composition is prepared from (A) a polyhydric alcohol having 5 or more carbon atoms and containing no cyclic structure, (B) a preservative (excluding the polyhydric alcohol having 5 or more carbon atoms) and (C) powder.SELECTED DRAWING: None

Description

  The present invention relates to a technique for preserving an emulsified composition.

  Skin external preparations such as cosmetics contain a thickener, a humectant, and the like in addition to water and oil, and often have conditions suitable for propagation of microorganisms. Therefore, there is a danger that microbes are accidentally mixed in and contaminated during the period from when the external preparation for skin is produced at the factory and distributed to the consumer through the distribution process and further until the cosmetic is consumed after opening. . Microorganisms contaminating skin preparations not only cause off-flavors, discoloration, and quality deterioration, but also cause skin damage due to deterioration of the ingredients, infectious diseases caused by pathogenic bacteria, and skin damage caused by bacterial components and metabolites. Could be

For this reason, it is common practice to add various antibacterial and preservatives as a measure against microbial contamination of the external preparation for skin. Conventionally, paraben (paraoxybenzoic acid ester) has been most widely used as a preservative for a skin external preparation (for example, Patent Document 1).
It is known that in a skin external preparation in an emulsified form, a surfactant incorporated for emulsification has a certain antibacterial effect (for example, Non-Patent Document 1).
In other words, it can be said that the skin external preparation in an emulsified form achieves the antibacterial property by the dual effect of the preservative and the surfactant.

  By the way, in recent years, cosmetics comprising a so-called surfactant-free emulsion composition have attracted attention because of less irritation to the skin. Examples of the surfactant-free emulsion composition include a Pickering emulsion (for example, Patent Document 2) and a polymer emulsion composition (for example, Patent Document 3).

JP 2015-113298 A JP 2010-527332 A JP-A-2013-131767

Doto et al., “Science and Technology of Cleaning and Sterilization,” Chapter 2, Section 1, “Sterilization Mechanism of Surfactants,” Science Forum Inc. (2000)

  As described above, a skin external preparation in a usual emulsified form is protected from microbial contamination by the antibacterial action of a preservative and a surfactant. However, in a so-called surfactant-free emulsion composition, specifically, a Pickering emulsion or a polymer emulsion composition, the antibacterial action of the surfactant cannot be obtained, so that there is a problem that the preservability is poor.

  In view of such problems, an object of the present invention is to provide a novel preservative technique for a surfactant-free emulsion composition.

The present invention for solving the above-mentioned problems has an emulsified composition which does not contain a low-molecular surfactant having a melting point of 80 ° C. or less and a weight average molecular weight of less than 5,000 in a content necessary for maintaining an emulsified system. (A) a polyhydric alcohol having 5 or more carbon atoms not containing a cyclic structure, (B) a preservative (excluding the polyhydric alcohol having 5 or more carbon atoms), and (C) powder An emulsified composition comprising a body.
The emulsified composition of the present invention exhibits excellent preservative properties due to the synergistic effect of (A) a polyhydric alcohol having 5 or more carbon atoms, (B) a preservative, and (C) a powder.

In a preferred embodiment of the present invention, the pickling emulsion is stabilized by the powder (C).
By using a Pickering emulsion, a stable emulsion composition can be obtained.

In a preferred embodiment of the present invention, the polyhydric alcohol (A) includes a polyhydric alcohol having a hydroxyl group at at least 1-position and 2-position and having 5 or more carbon atoms.
By using such a polyhydric alcohol, more excellent preservability can be obtained.

In a preferred embodiment of the present invention, the polyhydric alcohol (A) includes a diol having 5 or more carbon atoms.
The emulsified composition of the present invention containing a diol having 5 or more carbon atoms has better antiseptic properties.

In a preferred embodiment of the present invention, (D) a polyhydric alcohol having 4 or less carbon atoms not containing a cyclic structure is included.
By including such a polyhydric alcohol, the stability of the emulsified composition can be improved.

In a preferred embodiment of the present invention, the polyhydric alcohol (D) includes a diol having 4 or less carbon atoms.
By using a diol having 4 or less carbon atoms, an emulsified composition having better stability can be provided.

  The emulsion composition of the present invention is preferably in the form of a skin external preparation.

The present invention is a method for preserving an emulsified composition substantially free of a low-molecular surfactant having a melting point of 80 ° C. or lower and having a weight average molecular weight of less than 5,000, and (A) containing no cyclic structure A preservative, characterized by adding a polyhydric alcohol having 5 or more carbon atoms, (B) a preservative (excluding the polyhydric alcohol having 5 or more carbon atoms), and (C) a powder. Also about the method.
According to the preservation method of the present invention, the preservability of a surfactant-free emulsion composition that is easily contaminated by microorganisms can be improved.

In a preferred embodiment of the present invention, (D) a polyhydric alcohol having 4 or less carbon atoms not containing a cyclic structure is further added.
The stability of the emulsified composition can be improved by adding such a polyhydric alcohol.

  The emulsified composition of the present invention has excellent antiseptic properties. Further, according to the preservative method of the present invention, the preservability of a so-called surfactant-free emulsion composition can be improved.

9 is a transmission electron micrograph of the Pickering emulsion of Production Example 2.

<1> Emulsion composition Hereinafter, embodiments of the emulsification composition of the present invention will be described in more detail.
The emulsified composition of the present invention comprises a low-molecular surfactant having a melting point of 80 ° C. or less and a weight average molecular weight of less than 5,000 (hereinafter, also simply referred to as a low-molecular surfactant) in order to maintain an emulsified system. Not included in required content.

  For example, when the content of the low-molecular surfactant is preferably 0.5% by mass or less, more preferably 0.1% by mass or less, and still more preferably 0.01% by mass or less, the low-molecular-weight surfactant is emulsified. It is not contained in the content necessary for maintaining the system. "

  Examples of the low molecular surfactant include a nonionic surfactant, an anionic surfactant, a cationic surfactant and an amphoteric surfactant which are usually used in emulsified cosmetics.

  Examples of nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene hydrogenated castor oils, polyoxyethylene sorbitan fatty acid esters, sorbitan fatty acid esters, polyethylene glycol fatty acid esters, polyoxyethylene sorbit fatty acid Esters, polyglycerin fatty acid esters, alkyl glycerin ethers, glycerin fatty acid esters, polyoxyethylene cholesteryl ethers, alkyl polyglucosides, sucrose fatty acid esters, amine oxides, and the like.

  Examples of anionic surfactants include alkyl sulfates, alkyl amide ether sulfates, alkyl sulfonates, α-olefin sulfonic acids, alkyl amide sulfonates, alkyl aryl sulfonates, alkyl phosphates, polyoxyethylene Alkyl ether phosphates, acyl sarcosinates, acyl taurine salts, and the like.

  Examples of the amphoteric surfactant include alkyl acetate betaines, alkyl imidazolinium betaines, alkyl amide betaines, alkyl sulfo betaines, and the like.

  Examples of cationic surfactants include salts of primary, secondary or tertiary aliphatic amines, which may be polyoxyalkylenated, and quaternary ammonium salts.

  Essentially, an emulsified composition such as a Pickering emulsion that does not contain a low-molecular surfactant has poor antiseptic properties. However, the emulsified composition of the present invention exhibits excellent antiseptic properties due to the synergistic effect of (A) a polyhydric alcohol having 5 or more carbon atoms not containing a cyclic structure, (B) a preservative, and (C) a powder. I do. Hereinafter, “(A) a polyhydric alcohol having 5 or more carbon atoms not containing a cyclic structure”, “(B) preservative”, and “(C) powder” will be described.

The emulsion composition of the present invention contains (A) a polyhydric alcohol having 5 or more carbon atoms not containing a cyclic structure as an essential component.
The carbon number of the polyhydric alcohol having no cyclic structure in (A) is not particularly limited as long as it is 5 or more, but is preferably 5 to 10, more preferably 5 to 8, and even more preferably 5 to 6.
The polyhydric alcohol (A) may be a saturated alcohol or an unsaturated alcohol, but is preferably a saturated alcohol.

  Further, the number of hydroxyl groups of the polyhydric alcohol (A) is preferably 2 to 5, more preferably 2 to 4, further preferably 2 to 3, and further preferably 2. That is, the polyhydric alcohol (A) is particularly preferably a diol.

  The position where the hydroxyl group in the polyhydric alcohol (A) is bonded is not particularly limited, but it is preferable that the hydroxyl group is bonded to the terminal (that is, the first position). Particularly preferred are polyhydric alcohols having a hydroxyl group at least at the 1- and 2-positions.

Preferred examples of the polyhydric alcohol (A) include diols having a hydroxyl group at the 1-position and the 2-position.
Examples of such diols include 1,2-pentanediol, 1,2-hexanediol, 1,2-heptanediol, 1,2-octanediol, 1,2-nonanediol, 1,2-decanediol, and the like. Suitable examples include 1,2-pentanediol and 1,2-hexanediol.

  The content of the polyhydric alcohol (A) in the emulsified composition of the present invention is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and still more preferably from the viewpoint of improving the preservability. It is at least 0.5% by mass, more preferably at least 1% by mass.

  In addition, the content of the polyhydric alcohol (A) in the emulsion composition of the present invention is preferably 30% by mass or less, more preferably 20% by mass or less, and still more preferably from the viewpoint of the stability of the emulsion composition. It is at most 15% by mass, more preferably at most 10% by mass, further preferably at most 7% by mass, further preferably at most 4% by mass.

The preservative (B) can be used without any particular limitation as long as it is generally used as a preservative in a skin external preparation. Specifically, phenoxyethanol, benzoic acid and its salts, salicylic acid and its salts, phenol, sorbic acid and its salts, dehydroacetic acid and its salts, paraoxybenzoic acid esters (eg, methylparaben, ethylparaben, butylparaben, etc.), chlor Cresol, hexachlorophen, resorcin, isopropylmethylphenol, orthophenylphenol, benzalkonium chloride, chlorhexidine hydrochloride, chlorhexidine gluconate, alkylisoquinolium bromide, tricrycarbanilide, halocarban, photosensitizer 201, trichlorohydroxydiphenyl ether (Triclosan), methylchloroisothiazolinone / methylisothiazolinone liquid, bisabolol, alkyldiaminoethylglycine hydrochloride, Lolo salicylanilide (TCSA), tribromo-salicylanilide (TBS), and the like.
(B) As the preservative, only one kind may be used, or two or more kinds may be used in combination.

  The content of the preservative (B) in the emulsion composition is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, further preferably 0.5% by mass or more, from the viewpoint of improving the preservability. It is.

  In addition, the content of the preservative (B) in the emulsion composition is preferably 5% by mass or less, more preferably 3% by mass or less, and still more preferably 2% by mass or less, from the viewpoint of reducing skin irritation. .

The content ratio by mass of the polyhydric alcohol (A) to the preservative (B) in the emulsion composition is preferably 100: 1 to 1:10, more preferably 50: 1 to 1: 5, and further preferably 20. : 1 to 1: 3, more preferably 7: 1 to 1: 1, and more preferably 4: 1 to 2: 1.
By setting the ratio of (A) and (B) within the above range, the preservability and stability of the emulsified composition can be improved.

  The emulsified composition of the present invention contains (C) a powder. (C) The powder may be contained in any form, but is preferably contained in a form present at the interface between the oil phase and the aqueous phase. That is, the emulsion composition of the present invention is preferably in the form of a pickering emulsion stabilized by (C).

  (C) As powder, titanium dioxide, tin oxide, silica, iron oxide, clay mineral, aluminum oxide, nano-particle precipitated calcium carbonate, coal, magnesium oxide, magnesium trisilicate, etc., whose surface may be coated And inorganic powders such as ethyl cellulose, crystalline fatty alcohols and fatty acids, and resin particles (eg, polystyrene or polymethacrylate).

(C) When silica is used as the powder, for example, any of a so-called dry silica powder produced by vapor phase oxidation of a silicon halide and a so-called wet silica powder produced from water glass or the like is used. Is also good.
Examples of dry silica powder include Aerosil series (Nippon Aerosil Co., Ltd.), CAB-O-SIL series (Cabot Corporation), HDK series (Asahi Kasei Wacker Silicone Co., Ltd.), and examples of wet silica powder include Nipsil series (Tosoh Silica). And HI-SIL series (PPG).

(C) In the case where silica or metal oxide is used as the powder, the surface thereof is preferably subjected to a hydrophobic treatment.
Examples of the hydrophobizing treatment include a method of treating a powder with a hydrophobizing agent such as an organosilicon compound, silicone, hydrocarbon oil, fatty acid, fatty acid amide, fatty acid ester, higher alcohol, or polyoxyalkylene compound.
Particularly preferably, the powder is treated using an organosilicon compound or silicone as a hydrophobizing agent.

  Examples of the organosilicon compound include hexamethyldisilazane, monomethylsilane, dimethylsilane, trimethylsilane, trimethylethoxysilane, isobutyltrimethoxysilane, trimethylchlorosilane, dimethyldichlorosilane, methyltrichlorosilane, dimethylethoxysilane, dimethyldimethoxysilane, and diphenyldisilane. Ethoxysilane, hexamethyldisiloxane, palmitylsilane and the like can be mentioned. These are used in one kind or in a mixture of two or more kinds.

  Examples of the silicone include dimethyl silicone, methylphenyl silicone, α-methylstyrene-modified silicone, chlorophenyl silicone, and fluorine-modified silicone.

  The content of the powder (C) in the emulsion composition is not particularly limited, but may be preferably 0.1 to 5% by mass, and more preferably 0.5 to 2% by mass.

  In addition, the stability of the emulsified composition can be improved by using (D) a form containing a polyhydric alcohol having 4 or less carbon atoms not containing a cyclic structure.

  The carbon number of the polyhydric alcohol of (D) is not particularly limited as long as it is 4 or less, but is preferably 2 to 4, more preferably 3 to 4, and still more preferably 4.

  The number of hydroxyl groups in the polyhydric alcohol (D) is preferably 2 to 4, more preferably 2 to 3, and still more preferably 2. That is, the polyhydric alcohol (D) is particularly preferably a diol.

  The position where the hydroxyl group in the polyhydric alcohol (D) is bonded is not particularly limited, but it is preferable that the hydroxyl group is bonded to the terminal (that is, the 1-position). Particularly preferred are polyhydric alcohols having a hydroxyl group at the 1- and 2-positions or at the 1- and 3-positions.

  Preferred examples of the polyhydric alcohol (D) include 1,2-butylene glycol, 1,3-butylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, and 1,2-ethylene glycol. And particularly preferably 1,3-butylene glycol.

  The content of the polyhydric alcohol (D) in the emulsion composition is preferably 0.5% by mass or more, more preferably 1% by mass or more, and still more preferably 2% by mass, from the viewpoint of improving the stability of the emulsion composition. %, More preferably 3% by mass or more.

  The upper limit of the content of the polyhydric alcohol (D) in the emulsified composition is not particularly limited, but it is preferably 20% by mass or less, more preferably 10% by mass or less in terms of product design. .

The mass ratio of the polyhydric alcohol (A) to the polyhydric alcohol (D) is preferably 1:10 to 10: 1, more preferably 1: 5 to 5: 1, and still more preferably 1: 4 to 4. : 1, more preferably 1: 3 to 3: 1.
By setting the ratio of (A) to (D) in the above range, the preservability and stability of the emulsified composition can be improved.

  When the emulsified composition of the present invention is in the form of a Pickering emulsion, the average primary particle diameter of the emulsified powder can be 1 to 1000 nm as a guide, preferably 3 to 100 nm, more preferably 5 to 100 nm. 30 nm.

The average secondary particle diameter of the emulsified powder can be preferably about 1 μm or less, preferably 500 nm or less, more preferably 100 nm or less, and further preferably 50 nm or less.
Here, the average primary particle diameter and the average secondary particle diameter can be determined by measuring the maximum diameter of 2500 or more particles on a scanning electron microscope image and calculating the number average.
The average secondary particle diameter can be adjusted by the stress applied to the composition when emulsifying.

  The oil agent contained in the emulsified composition of the present invention is not particularly limited, and may contain liquid fats and oils, solid fats and oils, waxes, hydrocarbon oils, higher fatty acids, higher alcohols, ester oils, silicone oils, and the like.

  Examples of liquid fats and oils include avocado oil, camellia oil, turtle oil, macadamia nut oil, corn oil, mink oil, olive oil, rapeseed oil, egg yolk oil, sesame oil, persic oil, wheat germ oil, southern oil, castor oil, linseed oil , Safflower oil, cottonseed oil, eno oil, meadowfoam oil, soybean oil, peanut oil, teaseed oil, kaya oil, rice bran oil, sinagiri oil, Japanese kiri oil, jojoba oil, germ oil, triglycerin, glycerin trioctanoate, And glycerin triisopalmitate.

  As solid oils and fats, cacao butter, coconut oil, horse fat, hardened coconut oil, palm oil, tallow, sheep butter, hardened tallow, palm kernel oil, lard, beef bone fat, mocro kernel oil, hardened oil, beef leg fat , Molle, hardened castor oil and the like.

  The waxes include beeswax, candelilla wax, cotton wax, carnauba wax, bayberry wax, ibota wax, whale wax, montan wax, nuka wax, lanolin, kapok wax, lanolin acetate, liquid lanolin, sugar cane wax, lanolin fatty acid isopropyl, hexyl laurate, reduced lanolin, and jojo. Barrow, hard lanolin, shellac wax, POE lanolin alcohol ether, POE lanolin alcohol acetate, POE cholesterol ether, lanolin fatty acid polyethylene glycol, POE hydrogenated lanolin alcohol ether, and the like.

  Examples of the hydrocarbon oil include liquid paraffin, ozokerite, pristane, paraffin, ceresin, squalene, petrolatum, microcrystalline wax, hydrogenated polyolefin (having 6 to 20 carbon atoms), and the like.

  Examples of the higher fatty acids include lauric acid, myristic acid, palmitic acid, stearic acid, behenic (beheninic) acid, 12-hydroxystearic acid, undecylenic acid, and tolic acid.

  Examples of the higher alcohol include cetyl alcohol, stearyl alcohol, behenyl alcohol, butyl alcohol, myristyl alcohol, and cetostearyl alcohol.

  Ester oils include isopropyl myristate, cetyl octanoate, octyl dodecyl myristate, isopropyl palmitate, butyl stearate, hexyl laurate, myristyl myristate, decyl oleate, hexyl decyl dimethyl octanoate, isonyl isononanoate, cetyl lactate , Myristyl lactate, lanolin acetate, isocetyl stearate, isocetyl isostearate, sucrose stearate, sucrose oleate, cholesteryl 12-hydroxystearylate, ethylene glycol di-2-ethylhexylate, dipentaerythritol fatty acid ester, monoisostearate N- Alkyl glycol, neopentyl glycol dicaprate, diisostearyl malate, glycerin di-2-heptylundecanoate Trimethylolpropane tri-2-ethylhexylate, trimethylolpropane triisostearate, pentaneerythritol tetra-2-ethylhexylate, glycerin tri-2-ethylhexylate, trimethylolpropane triisostearate, cetyl 2-ethylhexanoate, 2 -Ethylhexyl palmitate, glyceryl trimmyristate, glyceride tri-2-heptylundecanoate, methyl ester of castor oil fatty acid, oleic acid oil, cetostearyl alcohol, acetoglyceride, 2-heptylundecyl palmitate, cetyl palmitate, adipic acid Diisobutyl, N-lauroyl-L-glutamic acid-2-octyldodecyl ester, di-2-heptylundecyl adipate, ethyl laurate, sebac Di-2-ethylhexyl acid, 2-hexyldecyl myristate, 2-hexyldecyl palmitate, 2-hexyldecyl adipate, diisopropyl sebacate, 2-ethylhexyl succinate, ethyl acetate, butyl acetate, amyl acetate, triethyl citrate And ethylhexyl methoxycinnamate.

  Examples of the silicone oil include chain polysiloxanes such as dimethylpolysiloxane, methylphenylpolysiloxane, methylhydrogenpolysiloxane, diphenylsiloxyphenyltrimethicone, pentasiloxane, decamethylpolysiloxane, dodecamethylpolysiloxane, and tetramethyltetrahydrogen. Cyclic polysiloxanes such as genpolysiloxane are exemplified.

  The emulsified composition of the present invention may contain optional components that are usually used in external preparations for the skin within a range that does not impair the effects of the present invention. Such optional components include, for example, xanthan gum, guar gum, quince seed, carrageenan, galactan, gum arabic, pectin, mannan, starch, curdlan, methylcellulose, hydroxyethylcellulose, carboxymethylcellulose, methylhydroxypropylcellulose, chondroitin sulfate, dermatan sulfate, Glycogen, heparan sulfate, hyaluronic acid, sodium hyaluronate, tragacanth gum, keratan sulfate, chondroitin, mucoitin sulfate, hydroxyethyl guar gum, carboxymethyl guar gum, dextran, kerato sulfate, locust bean gum, succinoglucan, caronic acid, chitin, chitosan, Carboxymethyl chitin, agar, polyvinyl alcohol, polyvinyl pyrrolidone, carboxy vinyl Polymers, sodium polyacrylate, polyethylene glycol, sodium acrylate grafted starch, stearoxyhydroxypropylmethylcellulose, bentonite, etc., among which water-soluble polysaccharides such as xanthan gum, agar, sodium acrylate grafted starch, stearyloxyhydroxypropyl Thickeners such as methylcellulose, moisturizing components such as sodium pyrrolidonecarboxylate, lactic acid, and sodium lactate; mica, talc, kaolin, synthetic mica, calcium carbonate, magnesium carbonate, and silicic anhydride (silica, which may be surface-treated) ), Powders such as aluminum oxide and barium sulfate, inorganic pigments such as cobalt oxide, ultramarine, navy blue and zinc oxide which may be surface-treated, iron oxide titanium dioxide sintered which may be surface-treated Pigments which may be surface-treated, such as titanium mica, fish phosphor foil, bismuth oxychloride, etc., pearlescent agents which may be laked, red 202, red 228, red 226, yellow 4 No., Blue No. 404, Yellow No. 5, Red No. 505, Red No. 230, Red No. 223, Orange No. 201, Red No. 213, Yellow No. 204, Yellow No. 203, Blue No. 1, Green No. 201, Purple No. 201, Organic pigments such as Red 204, polyethylene powder, polymethyl methacrylate, nylon powder, organic powders such as organopolysiloxane elastomers, lower alcohols such as ethanol and isopropanol, vitamin A or its derivatives, and vitamin B6 hydrochloride , Vitamin B6 tripalmitate, Vitamin B6 dioctanoate, Vitamin B2 or its derivatives, Vitamin B12, Vita Vitamin B such as min B15 or a derivative thereof, vitamin E such as α-tocopherol, β-tocopherol, γ-tocopherol, vitamin E acetate, vitamin D, vitamin H, pantothenic acid, pantethine, pyrroloquinoline quinone and other vitamins , Paraaminobenzoic acid, paraaminobenzoic acid monoglycerin ester, N, N-dipropoxyparaaminobenzoic acid ethyl ester, N, N-diethoxyparaaminobenzoic acid ethyl ester, N, N-dimethylparaaminobenzoic acid ethyl ester, N, N Benzoic acid derivatives such as N-dimethylparaaminobenzoic acid butyl ester, N, N-dimethylparaaminobenzoic acid ethyl ester, diethylaminohydroxybenzoylhexylbenzoate and the like; antacids such as homomenthyl-N-acetylanthranilate and the like Nylic acid derivatives; salicylic acid and its sodium salts, amyl salicylate, menthyl salicylate, homomenthyl salicylate, octyl salicylate, phenyl salicylate, benzyl salicylate, salicylic acid derivatives such as p-isopropanol phenyl salicylate; octyl cinnamate, ethyl-4-isopropyl cinnamate , Methyl-2,5-diisopropylcinnamate, ethyl-2,4-diisopropylcinnamate, methyl-2,4-diisopropylcinnamate, propyl-p-methoxycinnamate, isopropyl-p-methoxycinnamate, isoamyl-p -Methoxycinnamate, 2-ethylhexyl p-methoxycinnamate (ethylhexyl methoxycinnamate, octyl paramethoxycinnamate), 2-ethoxy Ciethyl-p-methoxycinnamate (cinoxate), cyclohexyl-p-methoxycinnamate, ethyl-α-cyano-β-phenylcinnamate, 2-ethylhexyl 2-cyano-3,3-diphenylacrylate (octocrylene), glyceryl Cinnamic acid derivatives such as mono-2-ethylhexanoyl-diparamethoxycinnamate, ferulic acid and derivatives thereof; 2,4-dihydroxybenzophenone, 2,2′-dihydroxy-4-methoxybenzophenone, 2,2′- Dihydroxy-4,4'-dimethoxybenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone (oxybenzone-3), 2-hydroxy-4-methoxy-4'-methyl Benzophenone, 2-hydro C-4-methoxybenzophenone-5-sulfonate, 4-phenylbenzophenone, 2-ethylhexyl-4'-phenyl-benzophenone-2-carboxylate, 2-hydroxy-4-n-octoxybenzophenone, 4-hydroxy- Benzophenone derivatives such as 3-carboxybenzophenone; 3- (4'-methylbenzylidene) -d, l-camphor; 3-benzylidene-d, l-camphor; 2-phenyl-5-methylbenzoxazole; 2,2 ' -Hydroxy-5-methylphenylbenzotriazole; 2- (2'-hydroxy-5'-t-octylphenyl) benzotriazole; 2- (2'-hydroxy-5'-methylphenylbenzotriazole; dibenzarazine; dianisoylmethane 5- (3,3-dimethyl-2- Norbornylidene) -3-pentan-2-one; dibenzoylmethane derivatives such as 4-t-butylmethoxydibenzoylmethane; octyltriazone; urocanic acid derivatives such as urocanic acid and ethyl urocanate; 2- (2′-hydroxy Hydantoin derivatives such as -5'-methylphenyl) benzotriazole, 1- (3,4-dimethoxyphenyl) -4,4-dimethyl-1,3-pentanedione, 2-ethylhexyl dimethoxybenzylidene dioxoimidazolidine propionate; Phenylbenzimidazozole sulfonic acid, terephthalidene dicane fursulfonic acid, drometrizole trisiloxane, methyl anthranilate, bisethylhexyloxyphenol methoxyphenyl triazine, rutin and its derivatives, oryzanol and its derivatives Ultraviolet absorbents such as derivatives as preferred.

  The emulsified composition of the present invention can be produced by mixing constituent components by a conventional method.

  The emulsion composition of the present invention is preferably in the form of a skin external preparation. Examples of skin external preparations include cosmetics, pharmaceuticals, and quasi-drugs.

<2> Preservation method The present invention also relates to a method of preserving a so-called surfactant-free emulsified composition substantially free of a low-molecular surfactant. The preservation method of the present invention is characterized by adding the polyhydric alcohol (A), the preservative (B) and the powder (C) to the emulsion composition.
In addition, "adding to an emulsion composition" means not only a form in which (A) to (C) are added to a prepared emulsion composition but also (A) to (A) to when an emulsion composition is prepared. The form to which (C) is added is also included.
The matters relating to the embodiment of the emulsified composition of the present invention described in the above <1> can be applied as they are to the preservative method of the present invention.

<Production Example 1>
At room temperature (25 ° C.), (b) the powder component was dispersed in the (a) aqueous phase component shown in Table 1, and (c) the oil phase component was added thereto with stirring to emulsify the mixture. An emulsified composition (Pickering emulsion) of a comparative example was produced.
The hydrophobized silica used was obtained by mixing silica fine particles (manufactured by AEROSIL) and a trimethylsilyl hydrophobizing agent.

<Test Example 1> Measurement of antiseptic properties The emulsified compositions of Examples and Comparative Examples were examined for antibacterial properties against fungi (Aspergillus niger) having a strong resistance to an antiseptic. That is, after 0.1 ml of the emulsified composition was spread on a plate medium of Sabouraud dextrose agar medium (SDA medium), the fungus was inoculated with a platinum loop. Based on the number of colonies that occurred one day after the inoculation, a three-stage evaluation was performed on the preservability as shown below. Which of the following three stages the colony number belongs to was determined by comparing the standard photograph of the colony number and the state of the specimen. Table 2 shows the results.
(Antiseptic)
○ ・ ・ ・ 0-1000
△ ・ ・ ・ 1001-3000
× ・ ・ ・ 3001 or more

<Test Example 2> Stability test The state of the emulsion compositions of Examples and Comparative Examples after standing at room temperature for one week was observed, and the stability of the emulsion compositions was evaluated according to the following criteria. Table 2 shows the results.
(Stability)
○ ・ ・ ・ No separation of oil phase and water phase is observed at all △ ・ ・ ・ Part of oil phase and water phase are separated × ・ ・ ・ Oil phase and water phase are completely separated

As shown in Table 2, the emulsified composition of Comparative Example 1 containing the preservative of (B) but not of the polyhydric alcohol of (A) was inferior in preservability. On the other hand, the emulsified compositions of Examples containing the polyhydric alcohol (A) and the preservative (B) were all excellent in preservability.
This result indicates that in the surfactant-free emulsified composition, the preservative property can be improved by using the polyhydric alcohol (A) and the preservative (B) in combination.

Further, despite containing the same amounts of the polyhydric alcohol (A) and the preservative (B), the emulsion composition of Example 1 which is a Pickering emulsion is a so-called polymer emulsion composition, Comparative Example 2 As compared with the emulsified composition of Example 1.
This result indicates that the excellent preservative property and stability in the emulsified compositions of the examples are obtained by the synergistic effect of the polyhydric alcohol (A), the preservative (B) and the powder (C). Is shown.

Also, as shown in Table 2, the emulsified compositions of Examples 1 to 6 containing 1,3-butylene glycol in an amount of 3% by mass or more contained Example 7 (1% by mass) having a relatively small amount of 1,3-butylene glycol. %) And the emulsion composition of Example 8 (0% by mass).
This result indicates that the stability can be improved by using the polyhydric alcohol (D) in the Pickering emulsion containing the polyhydric alcohol (A) and the preservative of (B).

<Production Example 2>
Using the same hydrophobized silica as in Production Example 1, a Pickering emulsion having the formulation shown in Table 3 (Reference Example) was produced in the same manner as in Production Example 1. Then, the Pickering emulsion of Reference Example was observed with a scanning electron microscope. An electron microscope image is shown in FIG.

The secondary particle diameter of silica in the Pickering emulsion of Reference Example was calculated based on FIG. As a result, the average secondary particle diameter of the silica was 50 nm or less.
The Pickering emulsions of the reference example and the example were produced using the same hydrophobized silica and by the same method. Therefore, the result of observation of the Pickering emulsion of the reference example with a scanning electron microscope shows that the average secondary particle diameter of the hydrophobized silica in the Pickering emulsion of the example is also 50 nm or less.

  The present invention can be applied to cosmetics.

Claims (9)

  An emulsified composition which does not contain a low-molecular surfactant having a melting point of 80 ° C. or less and a weight average molecular weight of less than 5,000 in a content necessary for maintaining an emulsified system. An emulsified composition comprising: a polyhydric alcohol having 5 or more carbon atoms, not containing, (B) a preservative (excluding the polyhydric alcohol having 5 or more carbon atoms), and (C) a powder. Stuff.   The emulsified composition according to claim 1, wherein the (C) is a Pickering emulsion stabilized by a powder.   The emulsion composition according to claim 1 or 2, wherein the polyhydric alcohol (A) has a hydroxyl group at least at the 1-position and the 2-position.   The emulsion composition according to any one of claims 1 to 3, wherein the polyhydric alcohol (A) is a diol.   The emulsion composition according to any one of claims 1 to 4, wherein (D) a polyhydric alcohol having a carbon number of 4 or less not containing a cyclic structure.   The emulsion composition according to claim 5, wherein the polyhydric alcohol (D) is a diol.   The emulsion composition according to any one of claims 1 to 6, which is a skin external preparation.   A method for preserving an emulsified composition substantially free of a low molecular weight surfactant having a melting point of 80 ° C. or less and having a weight average molecular weight of less than 5,000, wherein (A) carbon number not containing a cyclic structure is 5 or more A preservative method, comprising adding (B) a preservative (however, excluding the polyhydric alcohol having 5 or more carbon atoms) and (C) powder. 9. The preservative method according to claim 8, further comprising adding (D) a polyhydric alcohol having 4 or less carbon atoms not containing a cyclic structure.