Multi-layer cleaning composition

Abstract

An object of the present invention is to provide a multi-layer cleansing composition that maintains a sufficient makeup-removing effect like oil, has easy rinsability and a soft texture like a gel, and has an aesthetically pleasing appearance. The present invention relates to a multi-layer cleansing composition containing: (a) a nonionic surfactant having an HLB of 8 to 12, (b) an oil component, (c) a humectant, and (d) water, wherein the ratio [(a) / (b)] of the blending amount of the (a) nonionic surfactant to the blending amount of the (b) oil component is in the range of 0.4 to 0.8, and when the multi-layer cleansing composition is allowed to stand, it separates into a plurality of layers including (A) at least one bicontinuous microemulsion phase and (B) at least one oil phase. The composition reversibly becomes a single-layer gel by shaking.

Description

Technical Field

[0001] The present invention relates to a multi-layer cleansing composition. More specifically, it relates to a multi-layer cleansing composition that maintains excellent makeup removing effects, has rinsability and a soft texture similar to that of a gel, and has an aesthetically pleasing appearance. Background Art

[0002] With the improvement of the functions of makeup cosmetics, many (waterproof) products with excellent water resistance / sweat resistance have emerged on the market. From the perspective of facial cleansing, these are very difficult-to-rinse-off formulations. For these products, cleansing oils that mainly contain oil and are blended with a small amount of surfactants and ethanol, etc., and cleansing gels obtained by thickening emulsions containing a large amount of oil with water-soluble polymers, etc., are widely used in the facial cleansers used for makeup removal.

[0003] However, cleansing oils tend to leave oily components on the skin even after rinsing with water and do not provide a refreshing feeling. On the other hand, although cleansing gels can provide a refreshing feeling after rinsing, there are cases where the makeup removing effect is insufficient. In addition, for recent cosmetics, in addition to excellent functions as cosmetics (such as cleansing performance), an aesthetically pleasing appearance, that is, aesthetic properties, is also required.

[0004] Patent Document 1 discloses that a two-layer cleansing cosmetic composed of a liquid water layer and a liquid oil layer can achieve both the usability of a water-based cleansing cosmetic and the decontamination effect of an oil-based cleansing cosmetic. Patent Document 1 discloses a two-layer cleansing cosmetic composed of a liquid water layer and a liquid oil layer containing benzalkonium chloride or N-cocoyl-L-arginine ethyl ester / DL-pyrrolidone carboxylate. The above water layer contains a two-type surfactant, a polyhydric alcohol, hydroxyethyl cellulose and / or xanthan gum, an acyl amino acid salt type anionic surfactant and / or a nonionic surfactant with an HLB value of 8 to 12, and the above oil layer contains a liquid oil agent. By forming this two-layer cleansing cosmetic, the appearance of a transparent two-layer system can be maintained during storage, and uniform mixing can be achieved during mixing. However, there are the following problems: although uniform mixing can be achieved, the appearance is an opaque cloudy state and loses its beauty, and it is easy to drip from the hand due to low viscosity.

[0005] On the other hand, Patent Document 2 discloses an oily cleansing composition containing (A) a nonionic surfactant with an HLB of 6 to 14 and (B) an oily component, with the blending amount of water being less than 5% by mass, and it is described that when the composition and water are mixed at a ratio of 4:6, a micellar aqueous solution phase or a bicontinuous microemulsion phase is formed, and even when water is incorporated, it does not cause a reduction in the basic properties such as transparency, cleaning performance, and massage performance. The oily cleansing composition of Patent Document 2 forms a micellar aqueous solution phase or a bicontinuous microemulsion phase with a certain viscosity by mixing with water. Compared with conventional cleansing oils and double-layer cleansing cosmetics, these phases have viscosity but do not reach a viscosity where they do not drip at all. In addition, the removal effect on waterproof mascara and lipstick cannot be said to be sufficient. Furthermore, its appearance is a composition composed of one layer (oil phase) and does not change, so from the aesthetic point of view, it is sometimes not fully satisfactory.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Patent Publication No. 5419506

[0009] Patent Document 2: Japanese Patent Publication No. 4757446 Summary of the Invention

[0010] Problems to be Solved by the Invention

[0011] In view of the above technical situation, an object of the present invention is to provide a multi-layer cleansing composition that maintains a sufficient makeup removing effect like a cleansing oil, has easy rinsability and a soft texture like a cleansing gel, and has an aesthetic appearance.

[0012] Solutions for Solving the Problems

[0013] The inventors conducted in-depth research to obtain a multi-layer cleansing composition that forms (A) at least one bicontinuous microemulsion phase and (B) at least one oil phase separated from each other when standing and becomes a transparent single-layer gel when mixed during use, and as a result, completed the present invention.

[0014] That is, the present invention provides a multi-layer cleansing composition containing:

[0015] (a) a nonionic surfactant with an HLB of 8 to 12,

[0016] (b) an oil component,

[0017] (c) a humectant, and

[0018] (d) water,

[0019] The ratio [(a) / (b)] of the blending amount of the above-mentioned (a) nonionic surfactant to the blending amount of the above-mentioned (b) oil component is in the range of 0.4 to 0.8.

[0020] Upon standing, it separates into multiple layers including (A) at least one bicontinuous microemulsion phase and (B) at least one oil phase.

[0021] Effects of the Invention

[0022] The multi-layer cleansing composition of the present invention exhibits a fascinating appearance as follows: upon standing (during storage), it forms a multi-layer structure that perfectly separates into at least two layers of (A) a bicontinuous microemulsion phase and (B) an oil phase, and when in use, it becomes a transparent single-layer gel only by gently shaking. Furthermore, the multi-layer cleansing composition of the present invention maintains excellent makeup-removing effects and can achieve the easy rinsability of a gel and a soft texture. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a diagram showing a phase diagram (water - surfactant - oil component) of a ternary system for explaining the state of the composition of the present invention.

[0024] Figure 2 It is a diagram showing the change in the volume fraction of the (A) bicontinuous microemulsion phase in the total volume of the composition when changing the ratio [(a) / (b)] of the blending amount of the (a) nonionic surfactant to the blending amount of the (b) oil component in the composition of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0025] The multi-layer cleansing composition of the present invention will be described in detail below.

[0026] The multi-layer cleansing composition of the present invention (hereinafter sometimes also referred to as "composition" or "multi-layer composition") contains (a) a nonionic surfactant having an HLB of 8 to 12, (b) an oil component, (c) a humectant, and (d) water.

[0027] (a) A nonionic surfactant having an HLB of 8 to 12

[0028] The (a) nonionic surfactant (hereinafter also referred to as "(a) component") in the composition of the present invention is not particularly limited as long as it is a substance having an HLB value in the range of 8 to 12. Among them, a nonionic surfactant having an HLB in the range of 9 to 12 is preferably used.

[0029] The component (a) in the present invention may be composed of one nonionic surfactant with an HLB value of 8 to 12, or may be composed of a combination of two or more. The HLB value has additivity. When two or more nonionic surfactants are used in combination, the HLB value of the overall combination is represented as the weighted average of the HLB values of the individual surfactants.

[0030] The component (a) of the present invention must contain at least one nonionic surfactant with an HLB value of 8 to 12, and may optionally contain nonionic surfactants whose HLB values are not within the above range, that is, less than 8 or exceeding 12. Among them, it is preferred that the overall HLB value of the component (a) is within the range of 8 to 12. When the overall HLB of the component (a) is less than 8 or exceeds 12, it is difficult to obtain the desired multi-layer composition containing a bicontinuous microemulsion phase.

[0031] It should be noted that the "HLB (Hydrophilic Lipophilic Balance)" in this specification is the value calculated according to the following formula (I) (definition based on the "Kawakami formula")

[0032] HLB = 7 + 11.7·log(MW / MO) (I)

[0033] (where MW represents the molecular weight of the hydrophilic group part, and MO represents the molecular weight of the lipophilic group part).

[0034] As the nonionic surfactant (a) used in the present invention, there is no particular limitation as long as it can be used in cosmetics, etc. Examples thereof include polyglycerol fatty acid esters, polyoxyethylene glycerol fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitol fatty acid esters, polyoxyethylene lanolin / lanolin alcohol / beeswax derivatives, polyoxyethylene castor oil, polyoxyethylene hydrogenated castor oil, polyoxyethylene sterol / hydrogenated sterol, polyoxyethylene alkyl ether, polyoxyethylene polyoxypropylene alkyl ether, polyethylene glycol fatty acid esters, etc.

[0035] In the composition of the present invention, from the viewpoints of makeup removing effect and emulsion stability, it is preferred to use in combination 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), etc., and at least one nonionic surfactant selected from polyoxyethylene glycerol isostearates such as PEG-8 glycerol isostearate (HLB = 10), PEG-10 glycerol isostearate (HLB = 10), and PEG-15 glycerol isostearate (HLB = 12), etc. Among them, it is preferred to use the combination of PEG-8 glycerol isostearate and PEG-40 hydrogenated castor oil.

[0036] (a) The blending amount of the nonionic surfactant is preferably 10% by mass to 33% by mass, more preferably 15% by mass to 30% by mass, relative to the total amount of the composition. When the blending amount of the nonionic surfactant is less than 10% by mass or exceeds 33% by mass, it is difficult to obtain the desired multilayer composition.

[0037] (b) Oil

[0038] (b) As the oil, one or more kinds selected from liquid oily components commonly used in cosmetics and the like can be used. In particular, from the viewpoint of improving the makeup removing effect, a polar oil is preferably included.

[0039] Examples of the polar oil include liquid oils and ester oils. Examples of the liquid oil include linseed oil, camellia oil, macadamia nut oil, corn oil, mink oil, olive oil, avocado oil, camellia flower oil, castor oil, safflower oil, jojoba oil, sunflower oil, almond oil, rapeseed oil, sesame oil, soybean oil, peanut oil, triglycerol, glyceryl trioctanoate, glyceryl triisopalmitate, etc.

[0040] Examples of the ester oil include cetyl ethylhexanoate, glyceryl tri(ethylhexanoate), 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. In the present invention, cetyl ethylhexanoate and glyceryl tri(ethylhexanoate) among these are particularly preferably used.

[0041] (b) In the oil, other oils can be blended on the basis of the polar oil. Examples of the other oils include hydrocarbon oils and silicone oils.

[0042] Examples of the hydrocarbon oil include liquid paraffin, squalane, squalene, paraffin, isoparaffin, ozokerite, etc. Examples of the silicone oil include linear organosilicons such as dimethylpolysiloxane, methylphenylpolysiloxane, methylhydrogenpolysiloxane, and cyclic organosilicons such as octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane.

[0043] It should be noted that the oil in (b) of the present invention is preferably selected to have a refractive index difference of 0.5 or less from (d) water. If the refractive index difference between the oil in (b) and (d) water exceeds 0.5, the composition after shaking may become opaque.

[0044] (b) The compounding amount of the oil component is generally 20% to 55% by mass, preferably 30% to 50% by mass, based on the total amount of the composition. When the compounding amount of the oil component is less than 20% by mass, the makeup removing effect is reduced. When the compounding amount exceeds 55% by mass, it is difficult to obtain the desired multi-layer composition.

[0045] (c) Humectant

[0046] By compounding (c) the humectant into the composition of the present invention, a moist feeling can be imparted to the skin when used as a cleansing agent.

[0047] The (c) humectant used in the present invention is not particularly limited as long as it is a humectant that can be used in cosmetics and the like. Specific examples of the (c) humectant include 1,3-butanediol, polyethylene glycol, propylene glycol, dipropylene glycol, hexylene glycol, glycerin, diglycerin, xylitol, maltitol, maltose, D-mannitol, etc. One or more of these can be compounded in combination.

[0048] The compounding amount of the (c) humectant in the composition of the present invention is generally 10% to 30% by mass, preferably in the range of 15% to 25% by mass, based on the total amount of the composition. When the compounding amount of the (c) humectant is less than 10% by mass, the desired effect cannot be obtained. When it exceeds 30% by mass, there may be a case where a sticky feeling is instead brought about.

[0049] (d) Water

[0050] The compounding amount of the (d) water in the present invention is generally 5% to 20% by mass, preferably 6% to 15% by mass, and more preferably in the range of 7% to 10% by mass, based on the total amount of the composition. When the compounding amount of the (d) water is less than 5% by mass or exceeds 20% by mass, it is difficult to obtain the desired multi-layer composition.

[0051] (a) The compounding amount ratio of the nonionic surfactant to the (b) oil component [(a) / (b)]

[0052] In the composition of the present invention, the ratio [(a) / (b)] of the compounding amount of the above-mentioned (a) nonionic surfactant to the compounding amount of the above-mentioned (b) oil component must be in the range of 0.4 to 0.8. By setting this ratio (mass ratio) within the above-mentioned specified range, a fascinating multi-layer morphology in which it separates into a plurality of layers including (A) at least one bicontinuous microemulsion phase and (B) at least one oil phase at rest can be achieved. The above ratio [(a) / (b)] is further preferably set in the range of 0.5 to 0.7.

[0053] When the above ratio [(a) / (b)] is less than 0.4, even if separated into multiple layers, the proportion of the (B) oil phase becomes too large, resulting in reduced usability. Additionally, when the ratio [(a) / (b)] exceeds 0.8, the (A) bicontinuous microemulsion phase almost occupies the entire composition, and when it oscillates to form a gel-like state, the viscosity is low, and there is a situation of dripping from the hand.

[0054] When the above ratio [(a) / (b)] is approximately 0.4, the proportion of the (A) bicontinuous microemulsion phase in the total volume of the multi-layer composition during standing is approximately 0.5, and when the above ratio [(a) / (b)] is approximately 0.8, the proportion of the (A) bicontinuous microemulsion phase in the total volume of the multi-layer composition during standing reaches approximately 0.95. Therefore, from the perspective of aesthetics when separated into multiple layers, the above ratio [(a) / (b)] must also be set to 0.4 - 0.8.

[0055] (A) bicontinuous microemulsion phase

[0056] The bicontinuous microemulsion phase refers to the situation where the association number of the surfactant increases and associates infinitely, resulting in a dramatic increase in the soluble amounts of water and oil, and both water and oil form continuous channels. Whether it is a bicontinuous microemulsion phase can be determined by appearance judgment, making a phase equilibrium diagram, measuring conductivity, measuring the self-diffusion coefficient using NMR, and electron microscopy observation of replicas prepared by the freeze-fracture method, etc.

[0057] The bicontinuous microemulsion phase is a transparent low-viscosity single-phase region in appearance and is optically isotropic. It can be confirmed from the optically anisotropic liquid crystal phase by the following method: holding the sample between two polarizers combined with a 90-degree phase difference and confirming that there is no light transmission. Additionally, the following method is effective for distinguishing an isotropic surfactant continuous phase from other micellar aqueous solutions and reverse micellar oil solutions that are isotropic single-phase regions.

[0058] It is known that the conductivity of the bicontinuous microemulsion obtained by conductivity measurement is about 2 / 3 of the value of the micellar aqueous solution phase obtained using the same system. Measuring the self-diffusion coefficient using NMR is a method proposed by Lindman et al. and is described in detail in J.Colloid Interface Sci. 1981, 83, 569, etc. According to the electron microscopy observation of the bicontinuous microemulsion prepared by the freeze-fracture method, images of both water and oil being continuous can be obtained. Based on this image, it is easy to distinguish from the spherical aggregate images obtained in the continuous micellar aqueous solution phase of water or oil. This method is described in detail in the literature of Imamura et al., Colloid polym.Sci. 1994, 272, 604.

[0059] The bicontinuous microemulsion phase can be identified by the characteristics of being an isotropic, transparent, low-viscosity single region on the phase equilibrium diagram of a three-component system consisting of water / oil / surfactant, and having a region that is not continuous from either the water or oil vertex, and this characteristic varies depending on the constituent system. Figure 1 A general phase diagram with a bicontinuous microemulsion phase is shown.

[0060] Figure 1 Lα in the equation represents the liquid crystal phase, “I 双连续 " represents a single-phase bicontinuous microemulsion phase. It can be considered that the multilayer composition of the present invention when standing is Figure 1 The "II" in the figure shows that two phases have been separated.

[0061] (B) Oil phase

[0062] The oil phase (B) in the composition of the present invention is a phase composed of the same oil component as the oil component constituting the bicontinuous microemulsion phase (A). Figure 1 The phase diagram of 双连续 When the amount of water is fixed in the single-phase bicontinuous microemulsion phase shown in " and the (surfactant) : oil ratio is changed in the direction of oil-rich, the multi-layer composition of the present invention enters the region shown in "II" and presents a state where two layers are separated. In other words, it can be understood that the excess oil that cannot be completely absorbed by the (A) bicontinuous microemulsion phase appears in the upper layer of the (A) bicontinuous microemulsion phase to form the (B) oil phase.

[0063] As described above, the composition of the present invention separated into multiple layers (two layers) can be transformed into a single-layer gel-like composition by gently shaking. This change is reversible, and by allowing the single-layer gel-like composition to stand in advance, it can be restored to the phase-separated state again. Therefore, the user can be shocked by the obvious change in appearance.

[0064] In addition to the above essential ingredients, other optional ingredients commonly used in cosmetics, quasi-drugs, etc., particularly cleansing cosmetics, etc., may be blended into the composition of the present invention within a range that does not hinder the effects of the present invention. Other optional ingredients are not limited, and examples thereof include dyes, various drugs, buffers, chelating agents, preservatives, fragrances, etc.

[0065] As dyes of other optional components, water-soluble dyes and / or oil-soluble dyes can be used. If a water-soluble dye is used, only the (A) bicontinuous microemulsion phase is colored in a state of being separated into multiple layers, and the entire composition is colored when it is shaken to form a gel, so that the appearance change can be appreciated.

[0066] The composition (cosmetics) of the present invention can be produced, for example, by the following steps.

[0067] (1) Dissolving a water-soluble component to prepare a water-soluble fraction.

[0068] (2) Prepare an oil-soluble component by uniformly mixing oil-soluble ingredients.

[0069] (3) Thoroughly stir the above-mentioned (1) water-soluble component and (2) oil-soluble component to obtain a composition.

[0070] (4) Let the obtained composition stand still to separate it into (A) a bicontinuous microemulsion phase and (B) an oil phase.

[0071] The composition of the present invention is a multi-layer composition that perfectly separates into at least two layers when standing still, forms a gel-like state with a suitable viscosity that does not drip from the hand when gently shaken, and is a cleansing cosmetic with excellent makeup-removing effect, rinsing property, and usability. Therefore, the composition of the present invention is particularly suitable for providing as a cleansing cosmetic.

[0072] Examples

[0073] The following examples are listed to illustrate the present invention in more detail, but the present invention is not limited by these descriptions. It should be noted that the compounding amounts represent mass % unless otherwise specified.

[0074] Manufacture the compositions of each example according to the formulations shown in Tables 1 to 3 below by the following method.

[0075] Let the compositions of each example stand still and visually observe the appearance to evaluate whether they separate into (A) a bicontinuous microemulsion phase and (B) an oil phase, the proportion of the oil phase, and the state of each layer.

[0076] Next, vigorously shake the compositions of each example 10 times, evaluate whether they turn into a single-layer gel state, and then let them stand still again and observe the situation of returning to the original two-layer separation state (speed of separation).

[0077] For (1) "proportion of the oil phase" and (2) "speed of separation", the results of evaluation according to the following criteria are described.

[0078] (1) Proportion of the oil phase

[0079] ++: 50% or more

[0080] +: 40% - 49%

[0081] ±: 30% - 39%

[0082] -: 20% - 29%

[0083] --: Less than 20% (however, it separates into two layers)

[0084] ××: Does not separate, is a single layer

[0085] (2) Separation speed (time until separation)

[0086] ++: Less than 1 minute

[0087] +: 1 minute or more and less than 10 minutes

[0088] ±: 10 minutes or more and less than 6 hours

[0089] -: 6 hours or more

[0090] [Table 1]

[0091]

[0092] (*1) HLB = 10

[0093] (*2) HLB = 12

[0094] [Table 2]

[0095]

[0096] (*1) HLB = 10

[0097] [Table 3]

[0098]

[0099] (*1) HLB = 10

[0100] (*2) HLB = 12

[0101] (*3) HLB = 14

[0102] As Examples 1 to 12 of the composition of the present invention, when left standing, they are perfectly separated into (A) a bicontinuous microemulsion phase and (B) an oil phase, and become a single-layer gel-like composition when shaken. If these gel-like compositions are left standing, they return to the separated state again. In addition, when the compositions of Examples 1 to 12 are used as a cleaner in the state of a gel-like composition, the makeup-removing effect is excellent, and the rinsability and soft feeling are excellent.

[0103] In Comparative Example 1 where the ratio of (a) nonionic surfactant to (b) oil [(a) / (b)] is less than 0.4, although phase separation occurs, the oil phase accounts for more than 60% of the composition, and the appearance is not aesthetically pleasing. In addition, when used as a cleaner, a greasy feeling remains after rinsing. On the contrary, in Comparative Example 2 where the ratio [(a) / (b)] exceeds 0.8, it does not separate into two layers and has an ordinary appearance.

[0104] In Comparative Examples 3 to 6 using a nonionic surfactant having an overall HLB value exceeding 12 as the nonionic surfactant (a), although it separated into two layers, a bicontinuous microemulsion phase was not formed in the lower layer, and an uneven opaque composition was formed upon shaking.

[0105] Then, a composition having the formulation shown in Table 4 below was prepared, and the ratio of the volume of the bicontinuous microemulsion phase to the total volume of the composition in the separated state after standing was measured. The results are shown in Table 4 and Figure 2 .

[0106] [Table 4]

[0107]

[0108] (*1) HLB = 10

[0109] (*2) HLB = 12

[0110] As shown in Table 4 and Figure 2 shown, when the ratio of the nonionic surfactant (a) to the oil component (b) [(a) / (b)] is in the range of 0.4 to 0.8, the volume ratio of the bicontinuous microemulsion phase (bicontinuous phase) in the total volume of the composition reaches about 50% or more. Therefore, for example, when a water-soluble dye is compounded to color the bicontinuous phase, an impactful appearance in which more than about half of the composition is colored is formed. However, when the above ratio [(a) / (b)] exceeds 0.8, the oil component is entirely taken up into the bicontinuous phase to form a single-layer composition.

[0111] The composition of Example 1 of the present invention, a conventional single-phase bicontinuous microemulsion type cleaning agent (Comparative Example A: hereinafter also referred to as "single-phase type cleaning agent"), and a conventional cleaning oil (Comparative Example B) were prepared, and the makeup removing effects thereof were evaluated. The formulations of the single-phase type cleaning agent of Comparative Example A and the cleaning oil of Comparative Example B are shown in Table 5 below.

[0112] [Table 5]

[0113]

[0114] (Evaluation method)

[0115] A predetermined amount of various makeup products was uniformly applied on the surface of white artificial leather (L value: 93.37 (L0)) using a spatula. Twelve hours after the application, the L value (L1) of the portion coated with the cosmetic was measured using a color difference meter. Then, the coated portion of the artificial leather with the makeup was wiped 20 times back and forth with a tissue paper coated with 0.2 g of each makeup removing base agent of Example 1, Comparative Example A, or Comparative Example B, and the L value (L2) of the wiped portion was measured using a color difference meter.

[0116] Substitute the above measured values into the following formula to calculate the cleaning rate.

[0117] Cleaning rate (%) = (L2 - L1) / (L0 - L1) × 100

[0118] Perform the above measurement using commercially available (1) liquid foundation and (2) waterproof mascara as cosmetic makeup products, and show the results (cleaning rate) in Table 6 below.

[0119] [Table 6]

[0120] Makeup Removing Base Agent Example 1 Comparative Example A Comparative Example B (1) Liquid Foundation 82.67 70.46 74.74 (2) Waterproof Mascara 56.73 16.58 75.49

[0121] As shown in Table 6, for the emulsified liquid foundation, the multi-layer cleaning composition (Example 1) of the present invention has more excellent detergency than the conventional single-phase cleaner (Comparative Example A) and cleansing oil (Comparative Example B). For the waterproof mascara, it was confirmed that although it was inferior to the cleansing oil (Comparative Example B), it exhibited particularly excellent detergency compared to the conventional single-phase cleaner (Comparative Example A).

Claims

1. A multi-layer cleaning composition comprising: (a) a nonionic surfactant having an HLB of 8 to 12 in an amount of 15 to 30% by mass based on the total amount of the composition, (b) an ester oil in an amount of 30 to 50% by mass based on the total amount of the composition, (c) a humectant in an amount of 15 to 25% by mass based on the total amount of the composition, and (d) water in an amount of 5 to 20% by mass based on the total amount of the composition, wherein the ratio [(a) / (b)] of the blending amount of the (a) nonionic surfactant to the blending amount of the (b) ester oil is in the range of 0.4 to 0.8, when the multi-layer cleaning composition is allowed to stand, it separates into multiple layers including (A) at least one bicontinuous microemulsion phase and (B) at least one oil phase, the (a) nonionic surfactant comprises at least one selected from PEG-8 glyceryl isostearate, PEG-10 glyceryl isostearate, and PEG-15 glyceryl isostearate, and may further optionally comprise at least one selected from PEG-40 hydrogenated castor oil, PEG-20 hydrogenated castor oil, and PEG-30 hydrogenated castor oil, the (c) humectant is at least one selected from 1,3-butanediol, polyethylene glycol, propylene glycol, dipropylene glycol, hexylene glycol, glycerol, and diglycerol.

2. The composition according to claim 1, wherein The (a) nonionic surfactant comprises PEG-8 glyceryl isostearate and PEG-40 hydrogenated castor oil.

3. The composition according to claim 1, wherein, The ester oil is glyceryl tri(ethylhexanoate) and cetyl alcohol ethylhexanoate.

4. The composition according to claim 1 or 2, wherein, The difference in refractive index between the (b) ester oil and the (d) water is 0.5 or less.

5. The composition according to claim 1 or 2, which reversibly becomes a single-layer gel upon shaking.

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