Multi-layer cleansing composition

Abstract

The present invention aims to provide a multilayer cleansing composition that maintains a sufficient makeup-removal effect similar to oil, is easy to wash off and has a soft texture similar to gel, and has an aesthetically pleasing appearance. The present invention pertains to a multilayer cleansing composition that contains (a) a non-ionic surfactant having an HLB of 8-12, (b) oil, (c) a moisturizing agent, and (d) water. The ratio [(a) / (b)] between the blended amount of non-ionic surfactant (a) and the blended amount of oil (b) is within the range of 0.4–0.8. When left to stand, the multilayer cleansing composition separates into a plurality of layers including (A) at least one bi-continuous micro-emulsion phase and (B) at least one oil phase. The composition reversibly becomes a single layer of gel by being shaken.

Description

[Technical Field]

[0001] The present invention relates to a multi-layered cleansing composition, and more particularly to a multi-layered cleansing composition that maintains excellent makeup removal effect while having a gel-like ease of rinsing, a soft texture, and an aesthetically pleasing appearance. [Background technology]

[0002] As the functionality of makeup cosmetics improves, many waterproof products with excellent water and sweat resistance are now available on the market, but from the perspective of face washing, these products are very difficult to remove. Among the facial cleansers used to remove makeup, the most commonly used are cleansing oils, which contain oil as the main ingredient with small amounts of surfactants and ethanol, and cleansing gels, which are emulsions containing a large amount of oil thickened with water-soluble polymers.

[0003] However, cleansing oils tend to leave oily components on the skin even after rinsing with water, which can lead to a lack of a refreshing feeling. On the other hand, cleansing gels can provide a refreshing feeling after rinsing, but their makeup removal effect may be insufficient. In addition, in recent years, cosmetics have been required to have not only excellent cosmetic functions (e.g., cleansing performance) but also aesthetic qualities such as beautiful appearance.

[0004] Patent Document 1 describes a two-layer cleansing cosmetic comprising a liquid water layer and a liquid oil layer that combines the feel of an aqueous cleansing cosmetic with the dirt-removing effect of an oil-based cleansing cosmetic. Patent Document 1 describes a two-layer cleansing cosmetic comprising a liquid water layer containing benzalkonium chloride or N-cocoyl acyl-L-arginine ethyl-DL-pyrrolidone carboxylate, and a liquid oil layer. The aqueous layer contains an amphoteric surfactant, a polyhydric alcohol, hydroxyethyl cellulose and / or xanthan gum, an acylamino acid salt-type anionic surfactant, and / or a nonionic surfactant with an HLB value of 8 to 12, and the oil layer contains a liquid oil. This two-layer cleansing cosmetic maintains a transparent two-layer appearance during storage and is uniformly mixed. However, even when the two layers are uniformly mixed, the cosmetic has the disadvantages of an opaque, cloudy appearance that loses its aesthetic appeal, and its low viscosity makes it prone to dripping from the hands.

[0005] Meanwhile, Patent Document 2 discloses an oil-based cleansing composition containing (A) a nonionic surfactant with an HLB of 6 to 14 and (B) an oily component, with less than 5% by mass of water. When the composition is mixed with water in a ratio of 4:6, it forms a micellar aqueous solution phase or a bicontinuous microemulsion phase, and is said to prevent the basic properties of transparency, cleansing performance, and massage performance from being impaired even when water is mixed in. The oil-based cleansing composition of Patent Document 2 forms a micellar aqueous solution phase or a bicontinuous microemulsion phase with a certain degree of viscosity when mixed with water. While these phases are more viscous than conventional cleansing oils and two-layer cleansing cosmetics, they do not achieve a viscosity sufficient to prevent dripping. Furthermore, the removal effect of waterproof mascara and lipstick was insufficient. Furthermore, the appearance of the composition remains unchanged because it is a single-layer (oil phase) composition, which can sometimes be unsatisfactory from an aesthetic standpoint. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 5419506 [Patent Document 2] Patent No. 4757446 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0007] In view of the current state of the art as described above, the present invention aims to provide a multi-layered cleansing composition that maintains sufficient makeup removal effect like a cleansing oil, while having the ease of rinsing and soft texture like a cleansing gel, and also has an aesthetically pleasing appearance. [Means for solving the problem]

[0008] The inventors conducted extensive research to obtain a multi-layered cleansing composition that, when left to stand, forms a multi-layered composition in which (A) at least one bicontinuous microemulsion phase and (B) at least one oil phase are separated from each other, and that becomes a transparent single-layered gel when mixed during use, and as a result, they have arrived at the present invention.

[0009] That is, the present invention provides: (a) Nonionic surfactants with an HLB of 8 to 12, (b) oil content; (c) a moisturizer, and (d) water, the ratio [(a) / (b)] of the blending amount of the (a) nonionic surfactant to the blending amount of the (b) oil component is within the range of 0.4 to 0.8; A multi-layered cleansing composition is provided that upon standing separates into multiple layers comprising (A) at least one bicontinuous microemulsion phase and (B) at least one oil phase. [Effects of the Invention]

[0010] The multi-layered cleansing composition of the present invention, when left standing (during storage), forms a multi-layered structure beautifully separated into at least two layers, (A) a bicontinuous microemulsion phase and (B) an oil phase, and upon use, it presents an attractive appearance by becoming a transparent single-layer gel simply by shaking gently.Furthermore, the multi-layered cleansing composition of the present invention can provide a gel that is easy to rinse off and has a soft texture while maintaining excellent makeup removal effects. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing a three-component phase diagram (water-surfactant-oil) for explaining the state of the composition of the present invention. [Figure 2] 1 is a graph showing the change in the volume proportion of (A) the bicontinuous microemulsion phase in the total volume of the composition when the ratio [(a) / (b)] of the amount of (a) the nonionic surfactant to the amount of (b) the oil component is changed in the composition of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] The multi-layered cleansing composition of the present invention will be described in detail below. The multi-layered cleansing composition of the present invention (hereinafter also referred to simply as the "composition" or "multi-layered composition") contains (a) a nonionic surfactant having an HLB of 8 to 12, (b) an oil, (c) a moisturizer, and (d) water.

[0013] (a) Nonionic surfactants with an HLB of 8 to 12 The nonionic surfactant (a) (hereinafter also referred to as "component (a)") in the composition of the present invention is not particularly limited as long as it has an HLB value within the range of 8 to 12. Of these, nonionic surfactants with an HLB value within the range of 9 to 12 are preferably used. Component (a) in the present invention may consist of one or a combination of two or more nonionic surfactants having an HLB of 8 to 12. Additivity is recognized in HLB values, and when two or more nonionic surfactants are used in combination, the HLB value of the entire combination is expressed as a weighted average of the HLB values ​​of each surfactant alone.

[0014] Component (a) of the present invention must contain at least one nonionic surfactant with an HLB of 8 to 12, but may optionally contain a nonionic surfactant with an HLB outside the above range, i.e., less than 8 or more than 12. However, it is preferable that the HLB value of component (a) as a whole is within the range of 8 to 12. If the HLB value of component (a) as a whole is less than 8 or more than 12, it becomes difficult to obtain the intended multilayer composition containing a bicontinuous microemulsion phase.

[0015] In this specification, "HLB (Hydrophilic Lipophilic Balance)" refers to the following formula (I):

number

[0016] The nonionic surfactant (a) used in the present invention is not particularly limited as long as it is usable in cosmetics, etc. Examples thereof include polyglycerin fatty acid esters, polyoxyethylene glycerin fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbit fatty acid esters, polyoxyethylene lanolin-lanolin alcohol-beeswax derivatives, polyoxyethylene castor oil, polyoxyethylene hydrogenated castor oil, polyoxyethylene sterol-hydrogenated sterol, polyoxyethylene alkyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, polyethylene glycol fatty acid esters, etc.

[0017] In the composition of the present invention, a combination of at least one nonionic surfactant selected from polyoxyethylene hydrogenated castor oils such as PEG-40 hydrogenated castor oil (HLB=12), PEG-20 hydrogenated castor oil (HLB=10.5), and PEG-30 hydrogenated castor oil (HLB=11) and at least one nonionic surfactant selected from polyoxyethylene glyceryl isostearate such as PEG-8 glyceryl isostearate (HLB=10), PEG-10 glyceryl isostearate (HLB=10), and PEG-15 glyceryl isostearate (HLB=12) is preferred from the viewpoints of makeup removal effect and emulsion stability. Of these, a combination of PEG-8 glyceryl isostearate and PEG-40 hydrogenated castor oil is preferred.

[0018] The blending amount of (a) nonionic surfactant is preferably 10% by mass to 33% by mass, and more preferably 15% by mass to 30% by mass, based on the total amount of the composition. If the blending amount of (a) nonionic surfactant is less than 10% by mass or exceeds 33% by mass, it becomes difficult to obtain the intended multilayer composition.

[0019] (b) Oil content The oil (b) can be one or more selected from liquid oily components commonly used in cosmetics, etc. In particular, it is preferable to include a polar oil from the viewpoint of improving the makeup removal effect.

[0020] Examples of polar oils include liquid oils and ester oils, such as linseed oil, camellia oil, macadamia nut oil, corn oil, mink oil, olive oil, avocado oil, camellia oil, castor oil, safflower oil, jojoba oil, sunflower oil, almond oil, rapeseed oil, sesame oil, soybean oil, peanut oil, triglycerin, glycerin trioctanoate, and glycerin triisopalmitate.

[0021] Examples of ester oils include cetyl ethylhexanoate, triethylhexanoin, cetyl octanoate, hexyl laurate, isopropyl myristate, octyl palmitate, isocetyl stearate, isopropyl isostearate, octyl isopalmitate, isodecyl oleate, glyceryl tri-2-ethylhexanoate, pentaerythritol tetra-2-ethylhexanoate, 2-ethylhexyl succinate, diethyl sebacate, etc. Among these, cetyl ethylhexanoate and triethylhexanoin are particularly preferably used in the present invention.

[0022] The (b) oil component may contain other oil components in addition to the polar oil, and examples of the other oil components include hydrocarbon oils and silicone oils. Examples of hydrocarbon oils include liquid paraffin, squalane, squalene, paraffin, isoparaffin, ceresin, etc. Examples of silicone oils include linear silicones such as dimethylpolysiloxane, methylphenylpolysiloxane, and methylhydrogenpolysiloxane, and cyclic silicones such as octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecamethylcyclohexasiloxane.

[0023] In the present invention, it is preferable to select an oil component (b) such that the difference in refractive index between the oil component (b) and water (d) is 0.5 or less. If the difference in refractive index between the oil component (b) and water (d) exceeds 0.5, the composition may become opaque after shaking.

[0024] The blending amount of (b) oil is usually 20% by mass to 55% by mass, and preferably 30% by mass to 50% by mass, based on the total amount of the composition. If the blending amount of (b) oil is less than 20% by mass, the makeup removal effect will decrease, and if it is blended in more than 55% by mass, it will be difficult to obtain the intended multi-layered composition.

[0025] (c) Moisturizer By incorporating a moisturizing agent (c) into the composition of the present invention, when used as a cleansing agent, it is possible to give the skin a fresh, moist feeling.

[0026] The moisturizing agent (c) used in the present invention is not particularly limited as long as it is one used in cosmetics, etc. Specific examples of the moisturizing agent (c) include 1,3-butylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, hexylene glycol, glycerin, diglycerin, xylitol, maltitol, maltose, D-mannite, etc., and these may be blended alone or in combination of two or more.

[0027] The amount of (c) moisturizer in the composition of the present invention is usually 10% by mass to 30% by mass, and preferably 15% by mass to 25% by mass, based on the total amount of the composition. If the amount of (c) moisturizer is less than 10% by mass, the intended effect will not be obtained, and if it exceeds 30% by mass, the composition may feel sticky.

[0028] (d) water The blending amount of (d) water in the present invention is usually within the range of 5% by mass to 20% by mass, preferably 6% by mass to 15% by mass, and more preferably 7% by mass to 10% by mass, based on the total amount of the composition. If the blending amount of (d) water is less than 5% by mass or exceeds 20% by mass, it becomes difficult to obtain the intended multilayer composition.

[0029] The ratio of (a) nonionic surfactant to (b) oil [(a) / (b)] In the composition of the present invention, it is essential that the ratio [(a) / (b)] of the amount of the nonionic surfactant (a) to the amount of the oil (b) be in the range of 0.4 to 0.8. By maintaining this ratio (mass ratio) within the above-mentioned range, a beautiful multilayered morphology is achieved at rest, separated into multiple layers containing at least one bicontinuous microemulsion phase (A) and at least one oil phase (B). It is more preferable that the ratio [(a) / (b)] be in the range of 0.5 to 0.7.

[0030] If the ratio [(a) / (b)] is less than 0.4, even if the composition separates into multiple layers, the proportion of the (B) oil phase will be too high, resulting in poor usability. If the ratio [(a) / (b)] exceeds 0.8, the bicontinuous microemulsion phase (A) will account for almost the entire composition, resulting in a gel-like composition with low viscosity upon shaking, which may drip from the hands.

[0031] When the ratio [(a) / (b)] is about 0.4, the proportion of the bicontinuous microemulsion phase (A) in the total volume of the multilayer composition when left standing is about 0.5, and when the ratio [(a) / (b)] is about 0.8, it is about 0.95. Therefore, from the viewpoint of the aesthetic appearance when separated into multiple layers, it is necessary to set the ratio [(a) / (b)] to 0.4 to 0.8.

[0032] (A) Bicontinuous microemulsion phase A bicontinuous microemulsion phase is considered to be one in which the number of surfactant associations increases and they associate infinitely, resulting in a dramatic increase in the amount of water and oil solubilized, forming continuous channels for both water and oil. The existence of a bicontinuous microemulsion phase can be determined by visual inspection, creation of a phase equilibrium diagram, electrical conductivity measurement, measurement of the self-diffusion coefficient by NMR, and electron microscopy of replicas prepared using the freeze-fracture method.

[0033] The bicontinuous microemulsion phase is a transparent, low-viscosity, single-phase region that is optically isotropic. It can be distinguished from an optically anisotropic liquid crystal phase by holding a sample between two polarizing plates with a 90-degree phase difference and confirming that no light is transmitted. The following method is also effective for distinguishing an isotropic surfactant continuous phase from other isotropic single-phase regions, such as aqueous micellar solutions and reverse micellar oil solutions.

[0034] It is known that the electrical conductivity of bicontinuous microemulsions measured by electrical conductivity measurements is approximately two-thirds that of the aqueous micellar phase obtained from the same system. Measurement of the self-diffusion coefficient by NMR is a method described in detail by Lindman et al. in J. Colloid Interface Sci. 1981, 83, 569, among others. Electron microscopy of bicontinuous microemulsions prepared using the freeze-fracture method allows for the observation of continuous water and oil phases. This image is easily distinguishable from the spherical aggregates obtained in aqueous micellar phases where either water or oil is continuous. This method is described in detail in Imae et al., Colloid Polym. Sci. 1994, 272, 604.

[0035] A bicontinuous microemulsion phase can be identified by its characteristics, such as an isotropic, transparent, low-viscosity single-phase region on the phase equilibrium diagram of a ternary system consisting of water, oil, and surfactant, and not being continuous from either the water or oil apex, but these characteristics vary depending on the system. Figure 1 shows a typical phase diagram containing a bicontinuous microemulsion phase.

[0036] In Figure 1, Lα is the liquid crystal phase, バイコン " means one bicontinuous microemulsion phase. The multi-layer composition of the present invention when left standing is considered to be two separate phases, indicated by "II" in FIG.

[0037] (B) Oil phase The oil phase (B) in the composition of the present invention is a phase consisting of the same oil as the oil constituting the bicontinuous microemulsion phase (A). That is, the multi-layer composition of the present invention is a phase consisting of the oil phase (B) in the phase diagram of FIG. バイコンIn a single bicontinuous microemulsion phase represented by "," when the amount of water is fixed and the surfactant:oil ratio is changed in the oil-rich direction, it is thought to enter the region represented by "II" and assume a state of two separated layers. In other words, it is understood that the oil that cannot be completely incorporated into the (A) bicontinuous microemulsion phase appears in the upper layer of the (A) bicontinuous microemulsion phase and forms the (B) oil phase.

[0038] The composition of the present invention, which has been separated into multiple layers (two layers) as described above, becomes a single-layer gel composition upon gentle shaking. This change is reversible, and the single-layer gel composition returns to a phase-separated state upon leaving it undisturbed. Therefore, the change in appearance can have a significant impact on the user.

[0039] In addition to the above essential components, the composition of the present invention may contain other optional components that are commonly used in cosmetics, quasi-drugs, etc., particularly cleansing cosmetics, etc., within a range that does not impair the effects of the present invention. Examples of other optional components include, but are not limited to, dyes, various drugs, buffers, chelating agents, preservatives, fragrances, etc.

[0040] The dyes used as other optional components include water-soluble dyes and / or oil-soluble dyes. When a water-soluble dye is used, only the bicontinuous microemulsion phase (A) is colored in the multilayer separated state, and when the composition is shaken to form a gel, the entire composition becomes colored, allowing users to enjoy changes in appearance.

[0041] The composition (cosmetic) of the present invention can be produced, for example, by the following steps. (1) Dissolve the water-soluble components to prepare the water-soluble parts. (2) The oil-soluble components are mixed uniformly to prepare an oil-soluble part. (3) The above (1) water-soluble part and (2) oil-soluble part are thoroughly stirred to obtain a composition. (4) The resulting composition is allowed to stand and separate into (A) a bicontinuous microemulsion phase and (B) an oil phase.

[0042] The composition of the present invention is a multi-layered composition that separates beautifully into at least two layers when left standing, and upon gentle shaking, becomes a gel-like composition with a moderate viscosity that prevents dripping from the hands, providing a cleanser that not only has a makeup-removing effect but also has excellent rinsability and a pleasant feel when used. Therefore, the composition of the present invention is particularly suitable for use as a cleansing cosmetic. [Example]

[0043] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, the blending amounts are in mass %.

[0044] The compositions of the examples were prepared according to the formulations shown in Tables 1 to 3 below, in accordance with the above-mentioned method. The composition of each example was allowed to stand and its appearance was visually observed, and the presence or absence of separation into two phases, (A) a bicontinuous microemulsion phase and (B) an oil phase, the proportion of the oil phase, and the state of each phase were evaluated. Next, each composition was shaken vigorously 10 times, and the presence or absence of change into a single layer gel was evaluated, after which it was left to stand again and the state of returning to the original two-layer separated state (speed of separation) was observed.

[0045] The results of evaluation of (1) "oil phase ratio" and (2) "separation speed" based on the following criteria are shown below. (1) Oil phase ratio ++: 50% or more +: 40%~49% ±: 30%~39% -: 20%~29% --: Less than 20% (but separated into two layers) ××: One layer without separation (2) Separation speed (time until separation) ++: Less than 1 minute +: 1 minute or more but less than 10 minutes ±: 10 minutes or more and less than 6 hours -: 6 hours or more

[0046] [Table 1]

[0047] [Table 2]

[0048] [Table 3]

[0049] The compositions of Examples 1 to 12 of the present invention separated neatly into (A) a bicontinuous microemulsion phase and (B) an oil phase when left standing, and became a single-layer gel composition when shaken. These gel compositions returned to their separate state when left standing. Furthermore, when the compositions of Examples 1 to 12 were used as cleansing agents in the form of gel compositions, they were excellent in makeup removal effect, rinsability, and soft texture.

[0050] In Comparative Example 1, where the ratio of (a) nonionic surfactant to (b) oil [(a) / (b)] is less than 0.4, phase separation occurred, but the oil phase accounted for more than 60% of the composition, resulting in an unattractive appearance. Furthermore, when used as a cleansing agent, an oily feeling remained after rinsing. Conversely, in Comparative Example 2, where the ratio [(a) / (b)] is greater than 0.8, separation into two layers did not occur, resulting in a mundane appearance.

[0051] (a) In Comparative Examples 3 to 6, in which a nonionic surfactant with an overall HLB value of more than 12 was used as the nonionic surfactant, the composition separated into two layers, but the lower layer did not form a bicontinuous microemulsion phase, and when shaken, a non-uniform, opaque composition was obtained.

[0052] Next, compositions were prepared according to the formulations shown in Table 4 below, and the ratio of the volume of the bicontinuous microemulsion phase to the total volume of the composition after standing was measured. The results are shown in Table 4 and Figure 2.

[0053] [Table 4]

[0054] As shown in Table 4 and Figure 2, when the ratio of (a) nonionic surfactant to (b) oil [(a) / (b)] is within the range of 0.4 to 0.8, the volume of the bicontinuous microemulsion phase (bicon phase) accounts for approximately 50% or more of the total volume of the composition. Therefore, for example, by adding a water-soluble dye to color the bicon phase, the composition will have an appearance that is striking, with more than half of the composition being colored. However, when the ratio [(a) / (b)] exceeds 0.8, all of the oil is incorporated into the bicon phase, resulting in a single-layer composition.

[0055] The composition of Example 1 of the present invention, a conventional single-phase bicontinuous microemulsion cleansing agent (Comparative Example A: hereinafter also referred to as "single-phase cleansing agent"), and a conventional cleansing oil (Comparative Example B) were prepared and evaluated for their makeup removal effects. The formulations of the single-phase cleansing agent of Comparative Example A and the cleansing oil of Comparative Example B are as shown in Table 5 below.

[0056] [Table 5]

[0057] (Evaluation method) A predetermined amount of each makeup product was uniformly applied to the surface of white artificial leather (L value: 93.37 (L0)) using a doctor blade. 12 hours after application, the L value (L1) of the applied area was measured using a colorimeter. Next, the applied area of ​​the artificial leather was rubbed back and forth 20 times with a tissue coated with 0.2 g of each of the makeup remover bases from Example 1, Comparative Example A, or Comparative Example B, and the L value (L2) of the rubbed area was measured using the colorimeter. The above measurements are calculated using the following formula: Cleaning rate (%)=(L2-L1) / (L0-L1)×100 The cleaning rate was calculated by substituting

[0058] The results of the above measurement (cleaning rate) using commercially available (1) liquid foundation and (2) waterproof mascara as makeup cosmetics are shown in Table 6 below.

[0059] [Table 6]

[0060] As shown in Table 6, the multi-layered cleansing composition of the present invention (Example 1) has superior cleansing properties for emulsion-based liquid foundations compared to conventional single-phase cleansing agents (Comparative Example A) and cleansing oils (Comparative Example B). For waterproof mascara, although its cleansing properties are inferior to those of cleansing oils (Comparative Example B), it was confirmed to exhibit significantly superior cleansing properties compared to conventional single-phase cleansing agents (Comparative Example A).

Claims

1. (a) 15 to 30% by mass of a nonionic surfactant having an HLB of 8 to 12, based on the total amount of the composition; (b) 20 to 55 mass% of an ester oil based on the total amount of the composition; (c) a moisturizer in an amount of 15 to 25% by mass based on the total amount of the composition, and (d) containing 6 to 15% by mass of water based on the total amount of the composition; the (a) nonionic surfactant comprises at least one selected from PEG-8 glyceryl isostearate, PEG-10 glyceryl isostearate, and PEG-15 glyceryl isostearate; the moisturizing agent (c) is at least one selected from 1,3-butylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, hexylene glycol, glycerin, and diglycerin; a ratio [(a) / (b)] of the blending amount of the (a) nonionic surfactant to the blending amount of the (b) ester oil is within a range of 0.4 to 0.8; A multi-layered cleansing composition that separates into multiple layers upon standing, the multiple layers comprising (A) at least one bicontinuous microemulsion phase and (B) at least one oil phase.

2. The composition described in claim 1, wherein the (a) nonionic surfactant further comprises at least one selected from PEG-40 hydrogenated castor oil, PEG-20 hydrogenated castor oil, and PEG-30 hydrogenated castor oil.

3. The composition of claim 2, wherein the (a) nonionic surfactant comprises PEG-8 glyceryl isostearate and PEG-40 hydrogenated castor oil.

4. 10. The composition of claim 1, wherein the ester oil comprises triethylhexanoin and cetyl ethylhexanoate.

5. The composition according to claim 1 , wherein the difference between the refractive index of the (b) oil component and the refractive index of the (d) water is 0.5 or less.

6. The composition according to any one of claims 1 to 5, which reversibly becomes a single layer of gel upon shaking.

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