JP2020121953A - Cosmetic - Google Patents

Abstract

To provide a separation type layered cosmetic having a transparent oil layer and a transparent water layer in which the oil layer and the water layer are rapidly separated from an emulsion state due to shaking even in the case of a cosmetic comprising a high viscosity water layer and further to provide a cosmetic which suppresses the deterioration of appearance by adhesion of oil droplets generated in a layered cosmetic having transparent oil layer and a water layer to a cosmetic container wall.SOLUTION: There is provided a cosmetic having a layer in which at least an oil layer and a water layer are separated, which comprises (A) a butylene glycol fatty acid ester, (B) inorganic salts and (C) water.SELECTED DRAWING: Figure 1

Description

The present invention relates to an oil layer/water layer separate type cosmetic.

Cosmetics in which an oil layer and an aqueous layer are separated into two layers or multiple layers are commercially available. Such a cosmetic is usually lightly shaken at the time of use to emulsify and mix the oil layer and the aqueous layer, and applied to the skin as a uniform cosmetic at the time of use. Some of these separate cosmetics contain a surfactant and some do not, but they are appropriately designed according to the desired appearance characteristics such as whether both layers are transparent or one is milky white. There is. It is known that when a surfactant is not substantially added, a cosmetic having a high level of safety without skin irritation due to the surfactant is obtained (Patent Documents 1 and 2). Even when a surfactant is added, the amount of the cosmetic is relatively small and the safety is high. Since all of them are shaken at the time of use to make them uniform and then applied to the skin, they are widely used as cosmetics which can give the skin a moisturizing effect similar to that of an emulsion and a fresh feeling of use.
Further, since they are separated in the storage state (stationary state), there is an advantage that the water-soluble drug effect component and the oil-soluble drug effect component can be stably mixed.
For example, in the case where both layers are transparent as a two-layer cosmetic, it is required that the water layer and the oil layer have a transparent and beautiful appearance and that a clear interface is provided as design quality.

The oil layer and the water layer are shaken to be used from the separated storage state, but there is a trade-off between the ease of emulsification at this time and the ease of separation of the layer after shaking.
When it was easily shaken for emulsification, it was difficult to separate into two layers after emulsification, the interface was unclear, and the transparency of both layers was lowered, which tended to impair the aesthetics. On the other hand, if it is easy to separate the oil layer and the aqueous layer after shaking, it may be difficult to mix and emulsify by shaking, or even if a uniform cosmetic composition is obtained, the separation speed is too fast and the cosmetic composition is not uniform at the time of use. Then there was a problem.
On the other hand, there is a case where the viscosity of the cosmetic is increased by emphasizing the feeling and usability as a cosmetic, but in this case, it becomes difficult to solve the above problems. That is, the viscous property further lowers the separation ability between the oil layer and the water layer, and it is recognized that the appearance of both layers or one of them is turbid, and the appearance is significantly deteriorated.
Furthermore, in a cosmetic product that is made viscous, a part of the oil layer that cannot be completely separated adheres to the container wall as an oil drop, and the stain of the container due to this oil drop has been regarded as a factor that causes deterioration of aesthetics.

Under such circumstances, various types of multilayer cosmetics have been proposed. Patent Document 3, (a) 25 Viscosity at ° C. is at 30 to 400 mm ² / s non-volatile hydrocarbon oils, (b) a silicone oil viscosity at 25 ° C. is 30~400mm ² / s, (c ) Water, (d) a three-layer cosmetic composition comprising isostearic acid and an ester of polyglycerol. This multi-layered cosmetic composition controls the separation speed of the oil layer and the water layer, and by inserting a silicone oil between the oil phase and the water phase, even if a polar oil is contained in the oil phase, the cloudy layer is not directly contacted with the water phase. It is a technology that creates a beautiful layered cosmetic that never occurs. However, nothing is described about the separability of each layer when the viscosity of the aqueous phase is high.

Patent Document 4 proposes a cosmetic having a three-layer structure including an oil layer, an aqueous layer, and an emulsion layer, which contains a nonionic surfactant having an HLB of 2 to 7, an oily component, and water. .. An opaque emulsion layer is sandwiched between a transparent oil layer and a water layer. When it is permeated during use, the whole becomes an opaque emulsion, but if the viscosity of either layer is increased, it will not separate cleanly into the emulsion layer, oil layer, and water layer even if it is left standing, and the water layer and oil layer will become cloudy. There is a risk of doing it.

Patent Document 5 discloses a liquid multilayer cosmetic composition comprising an oil layer containing at least 5% natural oil and an aqueous layer containing 0.01% to 0.25% of a polymer selected from the group consisting of polysaccharides and sodium hyaluronate. Have been described. The cosmetic does not contain a surfactant, can be emulsified by stirring, does not separate the product during a single application, and does not form an emulsion layer between the oil layer and the water layer. , Has the property of separating easily. However, when the present invention was carried out, there was a problem that oil droplets adhered to the container wall, and the beauty of appearance, which is an important quality for cosmetics, could not be achieved. Furthermore, when the viscosity of the cosmetic is increased, there is a possibility that a problem may occur in the separability of the oil layer and the water layer.

In Patent Document 6, a nonionic surfactant having a specific diglyceryl group, an anionic surfactant having a specific phosphoric acid group, a water-soluble salt or organic acid, liquid oil, and water are blended in specific ratios. By doing so, a multilayer cosmetic composition is described which is easily and uniformly mixed by shaking to form a cloudy lotion, and is quickly separated when left standing. Among them, it contains 70 to 95 mass% of water and is selected from (A) diglycerin monopalmitate, diglycerin monolaurate, diglycerin monolauryl ether, diglycerin monomyristic ester and diglycerin monoisostearate. , A nonionic surfactant having a diglyceryl group 0.05 to 1% by mass, (B) a polyoxyethylene alkyl ether phosphate having 10 to 18 carbon atoms or an anion having a phosphate group which is a branched alkyl phosphate A composition containing 0.01 to 1% by mass of a surfactant, 0.01 to 3% by mass of (C) a water-soluble salt or organic acid, and 1 to 10% by mass of (D) a liquid oil is a lotion clouded by shaking. It is described that such a cosmetic composition separates into a transparent water layer and an oil layer when allowed to stand.
However, the cosmetic material disclosed in Patent Document 6 is a solution exhibiting a low viscosity of less than 100 mPa·s, and nothing is described about the separability of the water layer and the oil layer when the viscosity becomes higher than 100 mPa·s. It has not been. In addition, it is well known by those skilled in the art that the separability between the water phase and the oil layer is lowered particularly when the water layer has a high viscosity, and it is recognized as a problem to be solved.

JP, 2004-203764, A JP, 2017-0888569, A Japanese Patent No. 6262584 JP, 2002-003339, A Japanese Patent Publication No. 2018-510885 Japanese Patent No. 4045237

The present invention is a separation-type layered cosmetic having a transparent oil layer and a transparent water layer, and even when the cosmetic having a highly viscous water layer as a constituent element is emulsified by shaking. Therefore, it is an object to provide a cosmetic in which an oil layer and an aqueous layer are promptly separated. Another object of the present invention is to provide a cosmetic in which deterioration of aesthetics due to adhesion of oil droplets to a cosmetic container wall, which occurs in a layered cosmetic having a transparent oil layer and a water layer, is suppressed.

The main configuration of the present invention is as follows.
(1) A cosmetic having at least a layer in which an oil layer and an aqueous layer are separated, the cosmetic containing (A) butylene glycol fatty acid ester (B) inorganic salts (C) water.
(2) The cosmetic according to (1), wherein the (A) butylene glycol fatty acid ester is one or more substances selected from butylene glycol diisononanoate, butylene glycol laurate, butylene glycol sesquiisostearate, and butylene glycol stearate.
(3) It further contains (D) an oil agent other than (A), and the total amount of (A) butylene glycol fatty acid ester and (D) oil agent is 0.002 to 40 mass% per cosmetic (1) or ( Cosmetics according to 2).
(4) The cosmetic according to any one of (1) to (3), which contains (E) a water-soluble thickener.
(5) The cosmetic according to (4), wherein the water-soluble thickener (E) is one or more substances selected from cellulose gum, sodium carboxymethyl dextran, xanthan gum and tamarind gum.

According to the present invention, a separable layered cosmetic having a transparent oil layer and a transparent water layer can be obtained. Further, even when a water-soluble thickener is added to the water layer to give a viscous cosmetic, a layered cosmetic in which the oil layer and the water layer are rapidly separated from the emulsified state by shaking is provided. In addition, the cosmetic of the present invention maintains the transparency of the oil layer and the water layer and the clarity of the interface even after use, and oil droplets do not adhere to the container wall, so that the appearance after use is kept in a beautiful state. ..

It is a reference image for evaluating the transparency of the water layer and the oil layer constituting the layered cosmetic of the present invention.

The present invention relates to a layered cosmetic having a transparent oil layer and a transparent water layer.
The term "transparent" in the cosmetics as used herein is defined as "transparent" when 18-point characters can be read through a cosmetic layer filled in a PET container having a diameter of 4 cm.

The constituent components (blending components) of the present invention will be described.
Component (A): Butylene glycol fatty acid ester The component (A) of the present invention, a butylene glycol fatty acid ester, is a compound obtained by an ester bond reaction between butylene glycol and a fatty acid.
The fatty acid constituting the component (A) may be a saturated or unsaturated fatty acid having 8 to 22 carbon atoms, may be linear or branched, and may be a mixture thereof. Examples of these fatty acids include lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, oleic acid, behenic acid, sesquiisostearic acid, isononanoic acid and diisononanoic acid. The degree of esterification of the butylene glycol fatty acid ester is not particularly limited and may be a mixture of a plurality of types of esterification.

Specific examples of the butylene glycol fatty acid ester that is the component (A) of the present invention include butyrene glycol diisononanoate, butylene glycol laurate, butylene glycol sesquiisostearate, and butylene glycol stearate. Among them, fatty acid ester with 1,3-butylene glycol is preferable, and butylene glycol diisononanoate, butylene glycol laurate, butylene glycol sesquiisostearate, and butylene glycol stearate are particularly preferable.
All of the above butylene glycol fatty acid esters are commercially available as raw materials for cosmetics, pharmaceuticals, or foods, and are easily available.

The amount of the butylene glycol fatty acid ester as the component (A) is not particularly limited, but is 0.001 to 40% by mass, preferably 0.005 to 10% by mass, and more preferably 0.01% by mass relative to the total amount of the cosmetic. It is preferably 10 to 10% by mass. The butylene glycol fatty acid ester, which is the component (A), may form the oil layer alone. In consideration of variations in the feeling of use, it is preferable that the cosmetic of the present invention further contains (D) an oil agent other than the butylene glycol fatty acid ester, in addition to the (A) component butylene glycol fatty acid ester. When (D) an oil agent is further blended separately from the (A) component, the total amount of the (A) butylene glycol fatty acid ester and the (D) oil agent other than the butylene glycol fatty acid ester is 0.002 to 40 per cosmetic. The content of the butylene glycol fatty acid ester as the component (A) is preferably 0.001 to 0.1% by mass, and a sufficient separation effect of each layer is sufficiently exhibited. When the butylene glycol fatty acid ester which is the component (A) is dissolved and blended in the oil agent (D) to be blended as a part of the oil layer, there is a case where sufficient transparency and separability cannot be secured only by the oil agent (D). Also, the blending of (A) butylene glycol fatty acid ester improves the separation state of the oil layer and the water layer.

Component (B): Inorganic salts In the present invention, inorganic salts are blended as the component (B). The inorganic salt is a substance that can be mixed in cosmetics and foods, and is not particularly limited as long as it is soluble in water. Examples of the inorganic salts include sodium, potassium, calcium, aluminum, zinc, magnesium and the like hydrochlorides and sulfates. Sodium chloride is preferred.
The cosmetic of the present invention preferably contains an inorganic salt in an amount of 0.005 to 5% by mass, preferably 0.01 to 1% by mass, and particularly preferably 0.03 to 0.7% by mass, based on the total amount of the cosmetic. .. The inorganic salts dissolve in the water layer to improve the separated state of the oil layer and the water layer.

Component (C): Water The cosmetic of the present invention contains water as an essential component constituting the water layer. When the total amount of the cosmetic is 100, for example, (A): butylene glycol fatty acid ester, (B): inorganic salt, (D): oil agent, (E) water-soluble thickener, and dipropylene recall as an optional component are blended. In this case, the remaining amount other than the total amount (A+B+D+E+ optional component (dipropylene glycol)) is added as water. Water is preferably contained in an amount of 5 to 90% by mass based on the total amount of the cosmetic of the present invention.

Component (D): Oil agent In the cosmetic of the present invention, as described above, the butylene glycol fatty acid ester which is the component (A) can form an oil layer alone. However, in consideration of the variation in the feeling of use, it is preferable that the cosmetic of the present invention further contains (D) component: oil agent other than the butylene glycol fatty acid ester, in addition to the (A) component, butylene glycol fatty acid ester. In addition to the (A) component: butylene glycol fatty acid ester, the (D) component: an oil agent is preferably added to form an oil layer. Component (D): oil agent used in the present invention is not particularly limited as long as it is a substance used in cosmetics, pharmaceuticals, and quasi drugs. Component (D): The oil agent is preferably an oil agent which is liquid at room temperature. Examples of the liquid oil agent include vegetable oil, ester oil, hydrocarbon oil, silicone oil and the like. Specifically, olive oil, avocado oil, evening primrose oil, jojoba oil, squalane, triethylhexanoin, liquid paraffin, dimethylpolysiloxane/methylphenylpolysiloxane, octamethylcyclotetrasiloxane/decamethylcyclopentasiloxane/cyclopentasiloxane, etc. Is mentioned. Component (D): The oil agent may be used alone or in combination of two or more kinds. In the present invention, an oil agent that is paste-like, semi-solid or solid at room temperature may be added as long as it is compatible with an oil agent to be added and becomes a liquid. For example, an amino acid-based oil agent can be exemplified as the oil agent that is paste-like/semi-solid at room temperature. "Eldew (registered trademark)" is commercially available as a paste oil from Ajinomoto Co., Inc., and Eldew CL-301: N-lauroyl diglutamate (cholesteryl/behenyl/octyldodecyl), Eldew CL-202: N-lauroyl. Glutamate di(cholesteryl/octyldodecyl), Eldew PS-203: N-lauroyl glutamate di(phytosteryl/octyldodecyl), Eldew PS-304: N-lauroyl glutamic acid di(phytosteryl/behenyl/octyldodecyl), Eldew PS-306: Preferable examples are N-lauroylglutamate di(phytosteryl/behenyl/octyldodecyl) and Eldew APS-307:myristoylmethylalanine (phytosteryl/decyltetradecyl). Palm oil can be illustrated as a solid oil agent, and Carocino pure olein (palm oil) is marketed by Jena Corporation.
In the present invention, when (D): an oil agent is blended in addition to (A): butylene glycol fatty acid ester, the total amount of (A): butylene glycol fatty acid ester is 0.002 to 40 mass based on the total amount of the cosmetic. It is preferable to mix it so that it becomes%.

Component (E): Water-soluble thickener The cosmetic of the present invention is shaken at the time of use to mix an oil layer and an aqueous layer to make an emulsion, thereby obtaining a cosmetic. At this time, a water-soluble thickener can be further added in order to provide a more preferable feeling of use. (E): Examples of water-soluble thickeners include xanthan gum, locust bean gum, carrageenan, tamarind gum, gellan gum, cellulose gum, carboxymethyl dextran salt, guar gum, sclerotium gum, white jellyfish polysaccharides, alkaligenes-producing polysaccharides, and suisinzinori. Polysaccharides, agar, thickening polysaccharides such as pectin and pullulan, collagen, casein, gelatin, methylcellulose, methylhydroxypropylcellulose, hydroxyethylcellulose, sodium carboxymethylcellulose (CMC), sodium alginate, carboxyvinyl polymer (CARBOL, etc.), etc. Examples thereof include vinyl polymers and bentonite. Among them, thickening polysaccharides such as xanthan gum, locust bean gum, carrageenan, tamarind gum, gellan gum, cellulose gum, carboxymethyl dextran salt, guar gum, sclerotium gum, white jellyfish polysaccharide, alkalgenes-producing polysaccharide, suizenjinori polysaccharide, agar , Pectin and pullulan are preferable, and cellulose gum, carboxymethyl dextran salt, xanthan gum and tamarind gum are particularly preferable.

(E): When a water-soluble thickener is added, the cosmetic of the present invention has a viscosity of the aqueous layer under the condition (No. 1 rotor, 12 or 30 rpm) under the temperature control of 25° C. using a B type viscometer. , 30 seconds), it is preferably 100 to 350 mPa·s. If it is less than 100 mpa·s, it may be difficult to obtain the expected effect of improving the usability by blending the water-soluble polymer. If it exceeds 350 mPa·s, it may take more than 24 hours to separate the two layers to a state without turbidity after use. When a water-soluble thickener is added, its amount depends on the type of thickener and the water layer capacity of the cosmetic, so it may be set appropriately, but considering the effect of improving the feeling of use, the total amount of cosmetics On the other hand, it is preferable to add a water-soluble thickener in an amount of 0.01 to 2% by mass, preferably 0.05 to 1.5% by mass, and particularly preferably 0.1 to 1% by mass.

(Arbitrary component)
If necessary, the cosmetics of the present invention may optionally contain components that are usually added to cosmetics, as long as the effects of the present invention are not impaired. For example, lower alcohols such as ethanol and isopropyl alcohol, polyhydric alcohols such as glycerin, propylene glycol, dipropylene glycol, 1,3-butylene glycol, sorbitol and maltitol, preservatives, bactericides, ultraviolet absorbers and chelates. Examples thereof include agents, antioxidants, coloring agents such as dyes and pigments, fragrances, pH adjusters, agents such as sodium hyaluronate and vitamins.

The cosmetic of the present invention is a cosmetic having at least a transparent oil layer portion and a transparent water layer portion, and two layers having clear interfaces.

The cosmetic of the present invention is prepared by preparing a water layer solution and an oil layer solution by an ordinary method and filling the prepared water layer solution and oil layer solution in a container to obtain a cosmetic in which the oil layer and the water layer are separated.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples.
The blending amounts shown in the following examples and comparative examples are all% by mass.
<Example 1, Comparative Examples 1 and 2>
(A) component: butylene glycol butylene glycol diisononanoate as a fatty acid ester, (B) component: sodium chloride as an inorganic salt, (C) component: purified water as water, (D) component: squalane and triethylhexanoin as an oil agent A two-layer cosmetic (Example 1) was prepared. As a comparative example, two-layer cosmetics (Comparative Examples 1 and 2) were prepared using the polyglyceryl diisostearate-2 and the polyglyceryl diisostearate having properties similar to those of the butylene glycol fatty acid ester in place of the component (A). The composition is shown in Table 1. The viscosity of the aqueous layer and the obtained cosmetics were evaluated as follows.
[viscosity]
The viscosity of the aqueous layer was measured under conditions (No. 1 rotor, 12 or 30 rpm, 30 seconds) under the temperature control of 25° C. using a B type viscometer.
In addition, Example 1, Comparative Examples 1 and 2 have a composition not containing the component E: water-soluble thickener, and the aqueous layer viscosities were all below the measurement limit of the B-type viscometer. The description in the column of the viscosity of the water layer was described as "-".
[Evaluation]
The cosmetics were evaluated by filling each of the cosmetics in a PET container with a lid having a diameter of 4 cm, shaking the mixture sufficiently to eliminate the interface, and then adhering oil droplets to the container wall surface and the transparency of the water layer and the oil layer. It was visually evaluated. The evaluation was performed as follows.
Adhesion of oil droplets on the wall surface of the container: The adhesion state of the oil droplets on the wall surface was evaluated as “◯” when there was no adhesion and as “x” when there was adhesion.
Presence or absence of turbidity in the water layer after 4 hours: When left standing for 4 hours and clearly reading the 18-point type through the water layer (visible) is evaluated as "○", and when it cannot be clearly read (invisible) is " X” was evaluated.
Presence or absence of turbidity of oil layer after 24 hours: When left standing for 24 hours, a case where 18-point type can be clearly read through the oil layer (visible) is evaluated as "○", and when it cannot be clearly read (invisible) is "x". It was evaluated.
When any one of the above evaluation items was evaluated as x, it was determined that the separability was poor.
The evaluation criteria are shown in FIG.
The evaluation result of each cosmetic is shown in the lower part of Table 1.

As shown in Table 1, the composition of Example 1 containing D: oil agent in (A: butylene glycol fatty acid ester + B: inorganic salts + C: water) essential to the present invention was shaken, and allowed to stand after mixing. When a visual evaluation was conducted after a certain period of time, both the water layer and the oil layer had no turbidity and were evaluated as ◯. Then, the separation of the water layer and the oil layer was extremely clear, and there was no deposition of oil droplets on the wall surface of the container, and it was judged that the separability was good. However, the compositions (B+C+D) of Comparative Examples 1 and 2 lacking the (A) component: butylene glycol fatty acid ester of the present invention cannot obtain sufficient transparency of the oil layer after a lapse of 24 hours (x evaluation). ), the separability was judged to be poor. In the cosmetics of Example 1 and Comparative Examples 1 and 2, since the oil layers before shaking were transparent without turbidity, the cosmetics were shaken before use and allowed to stand still after use (at the time of next use ( (A): Butylene glycol fatty acid ester is used in order to obtain a separation-type cosmetic composition in which it is important to have a good appearance and a beautiful appearance after 4 to 24 hours in a general use method). It has been found that the composition of is important.
Next, the composition of the composition (A+B+C) of the present invention containing (D) an oil agent and further (E): a water-soluble thickener was similarly tested. In a layered cosmetic in which an oil layer and an aqueous layer are separated, if a water-soluble thickener is added to the aqueous layer, the feeling of use will be good, but since the viscosity will increase, it is necessary to restore the emulsified state after shaking to a good separated state. Becomes difficult.

<Examples 2 to 8 and Comparative Examples 3 to 10>
(A) component: butylene glycol butylene glycol diisononanoate or lauric acid butylene glycol as a fatty acid ester, (B) component: sodium chloride as an inorganic salt, (C) component: purified water as water, (D) component: squalane as an oil agent and Triethylhexanoin, (E) component: Two-layer cosmetics of Examples 2 to 8 (A+B+C+) in which any one of cellulose gum, carboxymethyl dextran Na, xanthan gum and tamarind gum was blended as a water-soluble thickener. D+E) was prepared. In the two-layer cosmetics of Examples 2 to 8, the viscosity of the water layer was adjusted to 100 to 350 mPa·s (when measured with a B-type viscometer at 25°C).
As a comparative example, a two-layer cosmetic (component of component (A): butylene glycol fatty acid ester-free composition (B+C+D+E) (water layer viscosity: 100 to 350 mPa·s) was prepared (Comparative Examples 3 to 10). ). The composition of each cosmetic is shown in Table 2.
The cosmetics were evaluated in the same manner as in Example 1.
The evaluation results are shown in the lower row of each composition in Examples and Comparative Examples in Table 2.

As shown in Table 2, the cosmetics of Examples 2 to 8 became transparent (○ evaluation) at a level where the oil layer and the water layer were not turbid and the letters were visible when left standing after use. And no oil droplets adhered to the container. And, all had an excellent usability. On the other hand, the cosmetics of Comparative Examples 3 to 10 in which the component (A): butylene glycol fatty acid ester was not blended were all shaken and then left to stand, and the oil layer became transparent (○ evaluation) at a level where characters without turbidity were visible. However, oil droplets adhered to the container wall, which was evaluated as ×. The cloudiness (transparency) of the water layer was also evaluated as ×.
In a layered cosmetic having an oil layer (D) and an aqueous layer (B+C), by further adding (E): a water-soluble thickener, the composition has a good feeling in use, but the aqueous layer has a high viscosity. Therefore, it becomes difficult to change the emulsified state after shaking to a good separated state. However, by blending the component (A): butylene glycol fatty acid ester, even if the composition (E): the water-soluble thickener is blended, a good separation state (both the water layer and the oil layer do not become turbid and the container wall It was found that (there is no adhesion of oil droplets).
Next, a test was conducted in which a fatty acid ester was blended as a substitute component for the component A.

<Examples 9 to 10 and Comparative Examples 11 to 16>
(A) component: butylene glycol butylene glycol stearate or sesquiisostearate butylene glycol as a fatty acid ester, (B) component: sodium chloride as an inorganic salt, (C) component: purified water as water, (D) component: squalane as an oil agent And triethylhexanoin, component (E): Two-layer cosmetics of Examples 9 and 10 were prepared in which cellulose gum was blended as a water-soluble thickener. In the two-layer cosmetics of Examples 9 and 10, the viscosity of the aqueous layer was adjusted to 100 to 350 mPa·s (when measured with a B-type viscometer at 25°C).
As a comparative example, two-layer cosmetics of Comparative Examples 11 to 16 having a composition containing fatty acid esters as a substitute component of the component (A) were prepared. Table 3 shows the composition of each cosmetic.
The cosmetics were evaluated in the same manner as in Example 1.
The evaluation results are shown in the lower row of each composition in Examples and Comparative Examples in Table 3.

As shown in Table 3, the cosmetics of Example 9 and Example 10 were used and evaluated in a good state of separation (both the water layer and the oil layer did not become turbid and oil droplets adhered to the container wall). It was evaluated as "No" and was found to be a preferable two-layer cosmetic. However, in Comparative Examples 11 to 16, turbidity of the water layer and the oil layer was observed in all of the evaluations after using and standing. In particular, Comparative Example 15 in which PEG-60 hydrogenated castor oil was mixed and Comparative Example 16 in which sorbitan stearate was mixed did not recover to the two-layer cosmetic state even after standing still after shaking and maintained the emulsified state.
Thus, even if the butylene glycol fatty acid ester, which is the component (A), is replaced with another fatty acid ester, the required quality (good separation state: both the water layer and the oil layer are not turbid, and oil droplets on the container wall It was revealed that a two-layer cosmetic (having no adhesion) could not be obtained. In order to obtain a good separation state (both the water layer and the oil layer are not turbid and oil droplets do not adhere to the container wall), it has been found that the addition of the (A) component: butylene glycol fatty acid ester is important. ..
Next, in the system in which the component (E) is blended, even if the component (D): oil agent is not blended, by taking the constitution (A+B+C) of the present invention, a preferable separation type cosmetic is obtained. In addition, a test was performed to confirm that the effects of the present invention can be obtained regardless of the type of component (D): oil agent and the combination thereof.

<Examples 11 to 18>
(A) component: 0.01 to 10% by mass of butylene glycol diisononanoate as a butylene glycol fatty acid ester, (B) component: sodium chloride as an inorganic salt, (D) component: squalane, triethylhexanoin, cyclopentasiloxane as an oil agent , Two kinds of olive fruit oil were combined, and (E) component: Cellulose gum was added as a water-soluble thickener to prepare two-layer cosmetics of Examples 11 to 16 (Examples 11 to 16). ). In Example 17, a two-layer cosmetic was prepared with a composition containing no oil agent other than component (A): butylene glycol fatty acid ester. Example 18 is a composition containing (D) component: solid oil (palm oil) as an oil agent. In the two-layer cosmetics of Examples 11 to 18, the viscosity of the aqueous layer was adjusted to 100 to 350 mPa·s (when measured with a B-type viscometer at 25°C).
Table 4 shows the composition of each cosmetic.
The cosmetics were evaluated in the same manner as in Example 1.
The evaluation results are shown in the lower part of Table 4.

As shown in Table 4, the cosmetic (A+B+C+E) of Example 17 does not contain the component (D): oil agent (oil agent other than the component A) according to the present invention, but similar to the other examples. It was a two-layer cosmetic having a preferable separating effect. In the present invention, it was confirmed that the component (D): an oil agent should be blended in order to make the feeling of use varied, but it is not an essential component for obtaining good separability.
The cosmetics (A+B+C+D+E) of Examples 11 to 16 and 18 containing the oil agent (D) other than the A component were used, and the appearance was visually evaluated after standing. It was evaluated as (both the water layer and the oil layer were not turbid, and the oil droplets did not adhere to the container wall), and it was a preferable two-layer cosmetic.
In the composition containing the oil agent (D) other than the A component, the test of the composition in which the A component is not blended is performed in Comparative Examples 1 to 16 as described above. Then, all of Comparative Examples 1 to 16 were evaluated as having poor separability, but from Examples 11 to 16 and 18, component (A): butylene glycol fatty acid ester was added in an amount of 0.01 to 0.05% by mass. Thus, it was confirmed that the problem of separability (turbidity of water layer or oil layer: Comparative Examples 1 to 16) that occurred when the compound was not blended was solved, and a preferable separation effect required for a two-layer cosmetic composition could be exhibited. Component (A): Butylene glycol fatty acid ester is highly safe, and even if it is blended alone into cosmetics, it has a good feeling to use, so the upper limit of the blending amount does not have to be set, but it is a guideline for the blending amount. As the component (A): 0.001 to 40% by mass of butylene glycol fatty acid ester, preferably 0.005 to 10% by mass, more preferably 0.01 to 10% by mass, and the total amount with other oil agents. It was considered to be preferable to blend so that 0.002 to 40 mass% with respect to the total amount of the cosmetic.
In addition, squalane, triethylhexanoin, cyclopentasiloxane, olive fruit oil, and palm oil which were added as the oil agent of the component (D) were all suitable for the purpose of adding to the cosmetic of the present invention.
Next, a test for confirming the effect of (B): inorganic salt in the present invention was conducted.

<Comparative Examples 17 to 18>
(B): Two-layer cosmetics (Comparative Examples 17 and 18) having a composition containing no sodium chloride corresponding to inorganic salts were prepared.
Comparative Example 17: 0.1% by mass of butylene glycol diisononanoate as the component (A), 5% by mass of squalane and triethylhexanoin as the component (D), and 1% by mass of cellulose gum as the component (E), A two-layer cosmetic in which the viscosity of the water layer is adjusted to 100 to 350 mPa·s (when measured at 25° C. with a B-type viscometer).
Comparative Example 18: Two-layer cosmetic having the same composition as Comparative Example 17 except that the component (A) was replaced with polyglyceryl-2 diisosterate-2 at 0.1% by mass.
Table 5 shows the composition of each cosmetic.
The cosmetics were evaluated in the same manner as in Example 1.
The evaluation results are shown in the lower part of Table 5.

In Comparative Example 17, turbidity of the water layer was observed. In Comparative Example 18, turbidity of the water layer and turbidity of the oil layer were observed. From the results of Comparative Example 17, it was found that a two-layer cosmetic having good separability could not be obtained even if (A): butylene glycol fatty acid ester was blended without blending the inorganic salt.

As described above, from the results of Examples and Comparative Examples, in a layered cosmetic having a transparent oil layer and a transparent water layer, from the mixed state after shaking and use, after standing, both the water layer and the oil layer have no turbidity. It has been found that it is important to mix (A) component: butylene glycol fatty acid ester and (B) component: inorganic salts in order to have a transparent appearance and prevent oil droplets from adhering to the container. Particularly, when the viscosity of the water layer is increased, the separability is deteriorated, which causes a problem that the transparency of the water layer and the oil layer is further reduced. In order to solve such a problem, the component (A): It was found that the addition of butylene glycol fatty acid ester and component (B): inorganic salt is effective.

Claims (5)

A cosmetic having at least a layer in which an oil layer and an aqueous layer are separated, the cosmetic containing (A) butylene glycol fatty acid ester (B) inorganic salts (C) water. The cosmetic according to claim 1, wherein the (A) butylene glycol fatty acid ester is one or more substances selected from butylene glycol diisononanoate, butylene glycol laurate, butylene glycol sesquiisostearate, and butylene glycol stearate. The (D) oil agent other than (A) is further contained, The total amount of the (A) butylene glycol fatty acid ester and the (D) oil agent is 0.002 to 40 mass% with respect to cosmetics. Cosmetics. The cosmetic according to any one of claims 1 to 3, which comprises (E) a water-soluble thickener. The cosmetic according to claim 4, wherein the water-soluble thickener (E) is one or more substances selected from cellulose gum, carboxymethyl dextran sodium, xanthan gum and tamarind gum.