JP3939821B2 - O / W / O type emulsion - Google Patents

Description

【００１９】
【製造例２】
【００２０】
【表２】

【００２１】
【製造例３】
【００２２】
【表３】

【００２３】
製造例１〜３とも、Ａ成分とＢ成分をマイクロフルイダイザー（みづほ工業製）を用いてＯ／Ｗ型マイクロエマルションとした。得られたマイクロエマルションの平均粒子径は光学顕微鏡で観察したところ、製造例１では７０ｍμ、製造例２では１５０ｍμ、製造例３では１００ｍμであった。
【００２４】
＜本発明のＯ／Ｗ／Ｏ型エマルションの実施例＞
製造例１〜３のＯ／Ｗ型エマルションを用いて、表４〜６の組成のＯ／Ｗ／Ｏ型エマルションを製造した。
【００２５】
【実施例１】
【００２６】
【表４】

【００２７】
Ａ成分とＢ成分をディスパーで混合し、５０００ｒｐｍで撹拌してＯ／Ｗ／Ｏ型エマルションを得た。
【００２８】
【実施例２】
【００２９】
【表５】

【００３０】
Ａ成分とＢ成分をディスパーで混合し、５０００ｒｐｍで撹拌してＯ／Ｗ／Ｏ型エマルションを得た。
【００３１】
【実施例３】
【００３２】
【表６】

【００３３】
Ａ成分とＢ成分をディスパーで混合し、５０００ｒｐｍで撹拌してＯ／Ｗ／Ｏ型エマルションを得た。
【００３４】
得られた実施例１のＯ／Ｗ／Ｏ型エマルションの電子顕微鏡写真を図１に示す。
【００３５】
【図１】
【００３６】
＜Ｏ／Ｗ／Ｏ型エマルションの安定性試験＞
次に実施例１のＯ／Ｗ／Ｏ型エマルションと、通常のディスパーを用いて製造した製造例１と同一組成のＯ／Ｗ型マイクロエマルションを用いて製造したＯ／Ｗ／Ｏ型エマルションを比較例１、Ｏ／Ｗ型マイクロエマルションの脂肪酸と水酸化カリウムの量を１０倍に増量（増量分は水で調整）してマイクロフルイダイザーで乳化して得られたＯ／Ｗ／Ｏ型エマルションを比較例２として、これらの経時安定性を比較した。結果を表７に示す。
【００３７】
【表７】

【００３８】
表７の結果に明らかなように、本発明のＯ／Ｗ／Ｏ型エマルションは非常に安定であった。
【００３９】
＜Ｏ／Ｗ／Ｏ型エマルションの使用テスト＞
実施例３のＯ／Ｗ／Ｏ型エマルションに対して、製造例３のマイクロエマルションの代わりに純水を用いて製造したＷ／Ｏ型エマルションを比較例３とし、女性専門パネラー１０名による使用感触の官能評価を実施した。評価項目は塗布時ののびの軽さと塗布後の保護感の２項目とし、それぞれ５段階で評価をつけてもらい、１０人の平均値で評価した。得られた結果を表８に示す。
【００４０】
【表８】

【００４１】
表８の結果から、本発明のＯ／Ｗ／Ｏ型エマルションは、Ｗ／Ｏ型エマルションに比べてきわめてのびが軽いにもかかわらず、塗布後の保護感はＷ／Ｏ型エマルションと同等以上であることが証明された。
【００４２】
また、本発明の実施例１のＯ／Ｗ／Ｏ型エマルション中のスクワランをスクワレンに全量置換したＯ／Ｗ／Ｏ型エマルションを製造し、別途同量のスクワレンを含有するＯ／Ｗ型エマルションを製造し、それぞれを４０℃の温度条件でキセノンテスターで１２時間処理してＴＢＡ法により、過酸化物の生成率を調べた。その結果、本発明のＯ／Ｗ／Ｏ型エマルションでは最内相に不飽和化合物であるスクワレンが存在するため、ＴＢＡ値は３と低かったが、Ｏ／Ｗ型エマルションではＴＢＡ値が５３まで上昇していた。この結果、本発明のＯ／Ｗ／Ｏ型エマルションでは不飽和化合物のような酸素に対する安定性の低い物質をきわめて安定に配合しうることが判明した。
【００４３】
【発明の効果】
本発明のＯ／Ｗ／Ｏ型エマルションは親水性界面活性剤の含有量が少ないにもかかわらず、水相成分を多量に含有でき、きわめて安定なＯ／Ｗ／Ｏ型エマルションを製造することができる。その結果、きわめてのびが軽く、Ｗ／Ｏ型エマルションに匹敵する塗布後の保護感を与えるエマルションを提供することが可能となった。また、本発明のＯ／Ｗ／Ｏ型エマルションは最内相に酸素に不安定な物質を安定に配合することが可能である。
【００４４】
【図面の簡単な説明】
実施例１のＯ／Ｗ／Ｏ型エマルションを凍結割断後、走査型電子顕微鏡で撮影した写真である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an O / W / O type emulsion, and more particularly to an extremely stable O / W / O type emulsion that can contain a large amount of an aqueous phase component even though the content of a hydrophilic surfactant is small. .
[0002]
[Prior art]
Conventionally, emulsified creams and emulsions are frequently used in cosmetics and external preparations for skin. Such emulsification forms can be broadly classified into W / O emulsion type and O / W emulsion type. Since the outer phase of the W / O emulsion is an oil phase, creams and emulsions with a high degree of protection when applied to the skin. However, there is a disadvantage that the elongation at the time of coating is poor. In recent years, it has become possible to reduce the poor elongation at the time of application by blending a silicone-based oil agent or a silicone-based surfactant, but it has not been sufficiently improved compared to O / W emulsions. is there. On the other hand, since the outer phase is an aqueous phase, the O / W type emulsion has a drawback that although the elongation of the cream or the emulsion at the time of application is good, the protective effect and moisturizing effect of the skin after application are not so high.
[0003]
As a method of making use of both of these characteristics, it has been proposed to form an O / W / O type emulsion. As a method for producing such an O / W / O type emulsion, there is generally a method in which an O / W type emulsion is prepared in the first stage and then this O / W type emulsion is dispersed in the oil phase as the second stage. It is used. However, the average particle size of the first stage O / W type emulsion is limited to about 1 μm by a generally known emulsification method, and therefore, the O / W type emulsion obtained by dispersing this O / W type emulsion in the oil phase. The average particle size of the W / O type emulsion is further increased and is likely to be unstable over time and with time. For this reason, it is necessary to add a considerable amount of a surfactant to make the first stage O / W emulsion into fine particles. In such a case, the desired fine particle O / W / O type emulsion could be produced. However, since the amount of the surfactant used in the production is large, the interaction between the surfactant and the other phase works strongly, and there is a problem that the emulsion is still unstable.
[0004]
Moreover, in the conventional method of obtaining an O / W / O type emulsion, in order to increase the content of the aqueous phase in order to give a refreshing feeling, there is a method of increasing the content of the aqueous phase by reducing the size of the emulsion. Conceivable. However, for this purpose, it is necessary to increase the amount of the hydrophilic surfactant in the conventional technique. In addition to the above-described problem of deterioration of the stability of the O / W / O emulsion, the amount of the surfactant is increased. Therefore, the touch at the time of application deteriorates, and even if the amount of water phase is increased to give a refreshing feeling at the time of application, it is canceled, and eventually an O / W / O type emulsion with a refreshing feeling is provided. It was difficult.
[0005]
[Problems to be solved by the invention]
That is, an object of the present invention is to provide an extremely stable O / W / O type emulsion that can contain a large amount of an aqueous phase of 40% by weight or more.
[0006]
[Means for Solving the Problems]
As a result of diligent research on this point, the inventors of the present invention have obtained even a very small amount of hydrophilic surfactant in the O / W type microemulsion obtained by applying a shearing force corresponding to a high-pressure homogenizer treatment of 400 atm or higher. A microemulsion having a size of 0.1 μm or less can be produced, and if this is further dispersed in an oil phase, an O / W / O type composite emulsion that is extremely stable with temperature and time can be obtained. Since the aqueous phase can be contained in the O-type emulsion in an amount of 40% by weight or more, it has been found that an emulsion with a refreshing feel that has never been obtained can be obtained, and the present invention has been completed.
[0007]
That is, the present invention relates to an O / W / O emulsion that can contain a large amount of an aqueous phase with a very small amount of a hydrophilic surfactant and that is stable over time and temperature.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
[0009]
In the present invention, as the A-component hydrophilic surfactant used for the production of the first stage O / W type emulsion, it is necessary to use a hydrophilic HLB in order to obtain an O / W type microemulsion. However, other than that, a normal hydrophilic surfactant can be used and is not particularly limited.
Specific examples include anionic surfactants such as fatty acid soaps such as sodium laurate and potassium palmitate, higher alkyl sulfates such as sodium lauryl sulfate and potassium lauryl sulfate, and polyoxyethylene (hereinafter referred to as “anionic surfactant”). Alkyl ether sulfates such as trilaurethanolamine lauryl sulfate, N-acyl sarcosine acids such as sodium lauroyl sarcosine, higher fatty acid amide sulfonates such as sodium N-myristoyl-N-methyl taurate, POE oleyl ether Phosphate ester salts such as sodium phosphate and POE stearyl ether phosphoric acid, sulfosuccinate such as sodium di-2-ethylhexyl sulfosuccinate, sodium dodecylbenzenesulfonate, dodecylbenzenesulfone Triethanolamine, alkyl benzene sulfonates, such as dodecylbenzene sulfonic acid, N- lauroyl glutamate monosodium, N- stearoyl glutamate disodium, N- acyl glutamates such as N- myristoyl -L- monosodium glutamate and the like.
Examples of the cationic surfactant include alkyltrimethylammonium salts such as stearyltrimethylammonium chloride and lauryltrimethylammonium chloride, dialkyldimethylammonium salts, alkyl quaternized ammonium salts, and alkylamine salts.
[0010]
Examples of amphoteric surfactants include 2-undecyl-N, N- (hydroxyethylcarboxymethyl) -2-imidazoline sodium, 2-cocoyl-2-imidazolinium hydroxide-1-carboxyethyloxy disodium salt, and the like. Imidazoline-based double-sided surfactant, 2-heptadecyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, lauryldimethylaminoacetic acid betaine, alkylbetaine, amide betaine, sulfobetaine and other betaine surfactants, N- Examples thereof include amino acid salts such as lauryl β-alanine and N-stearyl β-alanine.
[0011]
These hydrophilic surfactants can be used alone or in combination of two or more.
The oil component B used in the O / W type microemulsion produced as the first step in the present invention is not particularly limited as long as it is an oil component usually used in cosmetics. Liquid paraffin, squalane, squalene, pristane, hydrocarbons such as paraffin, petrolatum, etc., ethers such as dioctyl ether, diethers such as ethylene glycol dioctyl ether, cetyl octanoate, octyldodecyl myristate, isopropyl palmitate, Monoesters such as butyl stearate, myristyl myristate, decyl oleate and oleyl oleate, higher alcohols such as isostearyl alcohol and octyldodecanol, unsaturated higher alcohols such as oleyl alcohol and lanolin alcohol, etc. Higher fatty acids such as seric acid, diesters such as di-2-ethylhexyl sebacate, di-2-ethylhexyl adipate, glyceryl monoethers such as glycerol monooleyl ether, acid amides such as lauroyl lauryl amine, etc. 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, sasanqua oil, castor oil, flaxseed oil, safflower oil, cottonseed oil, Examples include eno oil, soybean oil, peanut oil, tea seed oil, kaya oil, rice bran oil, cinnagiri oil, Japanese kiri oil, jojoba oil, germ oil, cocoa butter, coconut oil, and animal oils. Among these oils, it is particularly preferable to use a low polarity oil such as liquid paraffin or a hydrocarbon oil such as squalane because the resulting O / W / O emulsion is further stabilized. In the present invention, one or more of these oils are used.
[0012]
The O / W type microemulsion produced in the first step in the present invention is preferably 0.01 to 1% by weight, preferably based on the total amount of the O / W / O type emulsion from which the hydrophilic surfactant is finally obtained. Is produced using an amount of 0.01 to 0.5% by weight. When an O / W type microemulsion is prepared by blending a hydrophilic surfactant in an amount exceeding 1% by weight with respect to the total amount of the finally obtained O / W / O emulsion, such an O / W type microemulsion is produced. When an O / W / O type emulsion is produced by dispersing the oil in the oil phase, the O / W type emulsion remains as an O / W / O type emulsion or the hydrophilic interface in the emulsion. The active agent affects the other phases, and the temperature stability and temporal stability of the obtained emulsion are extremely deteriorated. A range of 0.01% by weight to 0.5% by weight can be more stably produced, and is particularly preferable.
[0013]
Such an O / W type microemulsion containing a small amount of the hydrophilic active agent can give a strong shearing force to the hydrophilic component A component, the oil component B and the water C component. Adjustment can be performed using an emulsifier such as a high-pressure homogenizer or an ultrasonic emulsifier. In the case of using a high-pressure homogenizer, it is preferable to emulsify under a pressure of 400 atm or higher, more preferably emulsification at a temperature of 50 ° C. or higher and a pressure of 600 atm or higher. The average particle size of O / W microemulsion obtained in this manner is preferably in the range of 0.01~0.2μ m.
[0014]
In the O / W type microemulsion used in the present invention, various components generally used in cosmetics can be blended as optional components in addition to the hydrophilic surfactant, oil and water.
For example, lower alcohols such as ethyl alcohol, propyl alcohol, and isopropyl alcohol, polyhydric alcohols such as ethylene glycol, propylene glycol, 1,3-butylene glycol, glycerin, diglycerin, diethylene glycol, dipropylene glycol, and polyethylene glycol, sorbitan, Saccharides such as sorbitol, maltitol, maltotriose, mannitol, polysaccharides such as sodium hyaluronate, trehalose, sulfated trehalose and derivatives thereof, vitamins such as ascorbic acid, ascorbic acid phosphate ester, tocopherol, tocopherol acetate, vitamin A , Preservatives such as parabens and chlorhexidine gluconate, antioxidants such as butylhydroxytoluene, gum arabic, carboxyvinyl poly -Thickeners such as-, pH adjusters such as citrate and acetate, UV absorbers such as paraaminobenzoic acid derivatives and benzophenone derivatives, powders such as titanium oxide, silica gel and talc, fragrances, dyes, etc. Medicinal components such as acid, placenta extract, ginseng extract, sterol glycoside, β-carotene, superoxide desmutase and the like can be arbitrarily selected and used.
Further, a small amount of a lipophilic surfactant can be used in combination with the component A hydrophilic surfactant as long as the effects of the present invention are not impaired.
[0015]
In the present invention, this O / W type microemulsion is further dispersed in an oil phase to produce an O / W / O type emulsion. For the dispersion here, an emulsifier capable of giving a normal shearing force, such as a disper, is sufficient. The component of the oil phase in which the O / W type microemulsion is dispersed is not particularly limited as long as it is an oil component usually used in cosmetics. For example, the oil component exemplified in the O / W type microemulsion and volatile silicone oil Polydimethylsiloxane, organically modified polysiloxane, and the like can be used. In addition to this, it is more preferable to add an appropriate amount of a lipophilic surfactant such as a silicone-based surfactant or a sucrose fatty acid ester to the oil phase because a composite emulsion can be produced satisfactorily.
[0016]
Hereinafter, the present invention will be described with reference to production examples and examples.
<O / W type microemulsion>
O / W type emulsions of Production Examples 1 to 3 applied to the present invention were produced using the components shown in Tables 1 to 3.
[0017]
[Production Example 1]
[0018]
[Table 1]

[0019]
[Production Example 2]
[0020]
[Table 2]

[0021]
[Production Example 3]
[0022]
[Table 3]

[0023]
In each of Production Examples 1 to 3, the A component and the B component were converted into O / W type microemulsions using a microfluidizer (manufactured by Mizuho Kogyo). The average particle size of the obtained microemulsion was observed with an optical microscope, in Production Example 1 70 m mu, in Production Example 2 0.99 m mu, were in Production Example 3 100 m mu.
[0024]
<Example of O / W / O emulsion of the present invention>
Using the O / W type emulsions of Production Examples 1 to 3, O / W / O type emulsions having the compositions shown in Tables 4 to 6 were produced.
[0025]
[Example 1]
[0026]
[Table 4]

[0027]
A component and B component were mixed with a disper and stirred at 5000 rpm to obtain an O / W / O type emulsion.
[0028]
[Example 2]
[0029]
[Table 5]

[0030]
A component and B component were mixed with a disper and stirred at 5000 rpm to obtain an O / W / O type emulsion.
[0031]
[Example 3]
[0032]
[Table 6]

[0033]
A component and B component were mixed with a disper and stirred at 5000 rpm to obtain an O / W / O type emulsion.
[0034]
An electron micrograph of the obtained O / W / O emulsion of Example 1 is shown in FIG.
[0035]
[Figure 1]
[0036]
<Stability test of O / W / O type emulsion>
Next, the O / W / O type emulsion of Example 1 was compared with the O / W / O type emulsion produced using an O / W type microemulsion having the same composition as in Production Example 1 produced using a normal disper. Example 1 O / W / O type emulsion obtained by increasing the amount of fatty acid and potassium hydroxide of O / W type microemulsion 10 times (adjusted with water) and emulsifying with microfluidizer As Comparative Example 2, the stability over time was compared. The results are shown in Table 7.
[0037]
[Table 7]

[0038]
As is apparent from the results in Table 7, the O / W / O emulsion of the present invention was very stable.
[0039]
<Use test of O / W / O type emulsion>
In comparison with the O / W / O type emulsion of Example 3, a W / O type emulsion produced using pure water instead of the microemulsion of Production Example 3 is referred to as Comparative Example 3, and the feeling of use by 10 female panelists is provided. The sensory evaluation of was carried out. The evaluation items were two items of lightness at the time of application and a feeling of protection after application, and each was evaluated in five stages, and the average value of 10 people was evaluated. Table 8 shows the obtained results.
[0040]
[Table 8]

[0041]
From the results of Table 8, the O / W / O type emulsion of the present invention has a protection feeling after application that is equal to or higher than that of the W / O type emulsion although it is extremely light compared to the W / O type emulsion. Proven to be.
[0042]
In addition, an O / W / O type emulsion in which all the squalane in the O / W / O type emulsion of Example 1 of the present invention was replaced with squalene was produced, and an O / W type emulsion containing the same amount of squalene was separately prepared. Each was produced, treated with a xenon tester for 12 hours at a temperature of 40 ° C., and the peroxide production rate was examined by the TBA method. As a result, in the O / W / O type emulsion of the present invention, the squalene which is an unsaturated compound is present in the innermost phase, so the TBA value was as low as 3, but in the O / W type emulsion, the TBA value increased to 53. Was. As a result, it was found that the O / W / O type emulsion of the present invention can very stably contain a substance having low stability to oxygen such as an unsaturated compound.
[0043]
【The invention's effect】
The O / W / O type emulsion of the present invention can contain a large amount of an aqueous phase component despite the low content of the hydrophilic surfactant, and can produce an extremely stable O / W / O type emulsion. it can. As a result, it has become possible to provide an emulsion that is extremely light and gives a feeling of protection after application comparable to a W / O emulsion. In addition, the O / W / O type emulsion of the present invention can stably mix an oxygen unstable substance in the innermost phase.
[0044]
[Brief description of the drawings]
It is the photograph image | photographed with the scanning electron microscope after freeze-breaking the O / W / O type | mold emulsion of Example 1. FIG.

Claims (3)

A) A component containing 0.01 to 0.5% by weight of a hydrophilic surfactant, B) oil, and C) water based on the total amount of the O / W / O type emulsion corresponds to a high-pressure homogenizer treatment at 400 atm or higher. An O / W microemulsion having an average particle size of 0.01 to 0.2 μm obtained by applying a shearing force to be dispersed in an oil phase together with water and glycerin in the presence of a lipophilic surfactant. O / W / O type emulsion. The O / W / O type emulsion according to claim 1, wherein the amount of the water phase component is 40% by weight or more based on the total amount of the O / W / O type emulsion. A cosmetic comprising the O / W / O emulsion according to claim 1 or 2 .

Images