Two-layer cosmetic

Abstract

To provide cosmetics that offer a superior user experience, excellent separation properties when left standing, and a superior appearance. [Solution] A two-layer cosmetic composition comprising an aqueous phase (A) and an oil phase (B). The aqueous phase (A) comprises (a1) an amphoteric surfactant, (a2) an alkali metal salt, and (a3) ​​water, and the oil phase (B) comprises (b1) a linear hydrocarbon oil having 6 to 15 carbon atoms. Component (B) does not contain silicone oil, or the silicone oil content based on the total mass of component (B) is 1% by mass or less.

Description

Technical Field

[0001] The present invention relates to cosmetics. More specifically, it relates to cosmetics that separate into two layers when standing still but easily emulsify when shaken. The present invention is

Background Art

[0002] There is known a two-layer type cosmetic that separates into two layers when standing still as a cosmetic, but is emulsified by shaking at the time of use and then applied. Such a cosmetic generally contains an aqueous phase composed of an aqueous component and an oil phase composed of an oily component. By applying such a two-layer type cosmetic to the skin or the like after shaking, it is possible to simultaneously obtain the feeling of use and efficacy obtained by the aqueous component and the feeling of use and efficacy obtained by the oily component. Therefore, it has the characteristic that the advantages of both aqueous cosmetics and oily cosmetics can be obtained at once.

[0003] On the other hand, it is known that by utilizing silicone-free volatile oils in cosmetics, a refreshing feeling of use can be obtained. Also, such cosmetics are known to exhibit high detergency. Furthermore, from the consideration for the environment, it is preferable not to adopt silicone compounds.

[0004] However, it has been found that when a silicone-free volatile oil is blended into the above two-layer type cosmetic, it cannot be cleanly separated into two layers when standing still, and the appearance tends to be inferior. Since each of the two layers has a transparency when standing still, resulting in a high-class feeling, it is desired to have high separability when standing still.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

[0006] The present invention provides the following: [1] (a1) Amphoteric surfactants, (a2) Alkali metal salts and (a3) an aqueous phase (A) comprising water, and (b1) Oil phase (B) comprising a straight-chain hydrocarbon oil having 6 to 15 carbon atoms A two-layer cosmetic composition containing, (B) A cosmetic product in which component (B) does not contain silicone oil, or the silicone oil content based on the total mass of component (B) is 1% by mass or less. [2] (a1) The cosmetic composition according to [1], wherein the component is selected from the group consisting of lauryl betaine, cocamidopropyl betaine, and sodium cocoamphoacetate. [3] (a2) The cosmetic composition according to [1] or [2], wherein the component is sodium chloride. [4] (B) A cosmetic composition according to any one of [1] to [3], wherein the content of (b1) based on the total mass of component (B) is 85% by mass or more. [5] (B) A cosmetic composition according to any one of [1] to [4], comprising a hydrocarbon oil having 9 to 12 carbon atoms. [6] A cosmetic composition according to any one of [1] to [5], wherein the content of component (A) is 40 to 90% by mass and the content of component (B) is 10 to 60% by mass, based on the total mass of the cosmetic composition. [7] The cosmetic composition according to any one of [1] to [6], wherein the content of component (a1) is 0.07 to 2% by mass, and the content of component (a2) is 0.1 to 1.5% by mass, based on the total mass of the cosmetic composition. [8] A cleansing agent, a cosmetic product as described in any of [1] to [7].

[0007] According to the present invention, a cosmetic composition is provided that offers excellent usability, high separation properties during standing, and a superior appearance. Furthermore, when the cosmetic composition of the present invention is used as a cleansing agent, it exhibits high cleansing effectiveness in terms of both usability and cleansing properties. Specific description of the invention

[0008] The two-layer cosmetic composition according to the present invention (hereinafter sometimes simply referred to as "cosmetic composition") is (a1) Amphoteric surfactants, (a2) Alkali metal salts and (a3) an aqueous phase (A) comprising water, and (b1) Oil phase (B) comprising a straight-chain hydrocarbon oil having 6 to 15 carbon atoms It consists of the following. Each of these components, as well as any additional components that may be added, are described below.

[0009] (A) Aqueous phase The cosmetic composition according to the present invention comprises two phases: (A) an aqueous phase and (B) an oil phase, where (A) the aqueous phase is (a1) Amphoteric surfactants, (a2) Alkali metal salts and (a3) water It comprises the following. By combining these components, excellent properties can be achieved even without including silicone oil in the (B) oil phase, which will be described later. Components (a1) to (a3) ​​are described below.

[0010] (a1) Amphoteric surfactant The present invention uses an amphoteric surfactant (hereinafter sometimes referred to as component (a1)). In the present invention, the term "amphoteric" means (i) an ionic compound in which the molecule contains both acidic and basic sites, for example, an ionic compound containing both a basic functional group and an acidic functional group, or (ii) a dipolar ionic compound having both positive and negative charges in the same molecule.

[0011] Component (a1) is considered to contribute to the separation of the water layer and the oil layer in the two-layer cosmetic composition according to the present invention. The amphoteric surfactants that can be used are not particularly limited, but for example, imidazoline-based amphoteric surfactants and betaine-based amphoteric surfactants are preferably used. Specifically, examples include lauryl betaine, cocamidopropyl betaine, lauryldimethylaminoacetic acid betaine, amide betaine, sulfobetaine, sodium cocoamphoacetate, 2-undecyl-N,N,N-(hydroxyethylcarboxymethyl)-2-imidazoline sodium, and 2-cocoyl-2-imidazolinium hydroxide-1-carboxyethyloxy disodium salt. Of these, those selected from the group consisting of lauryl betaine, cocamidopropyl betaine, and sodium cocoamphoacetate are preferred. Two or more of these (a1) components can be used in combination.

[0012] (a1) The content of the component is preferably 0.07 to 2% by mass, and more preferably 0.1 to 1% by mass, based on the total mass of the two-layer cosmetic composition.

[0013] (a2) Alkali metal salts In the cosmetic composition according to the present invention, the (A) aqueous phase contains an alkali metal salt (hereinafter referred to as component (a2)). This alkali metal salt dissolves together with component (a1) in the water (a3), which will be described later, in the aqueous phase and affects the ionic phase equilibrium. Such component (a2) is not particularly limited, and as alkali metal ions, sodium ions, potassium ions, lithium ions, rubidium ions, etc. can be selected, and as counterions, chloride ions, carbonate ions, bicarbonate ions, nitrate ions, sulfate ions, etc. Specifically, sodium chloride, potassium chloride, sodium carbonate, sodium bicarbonate, potassium carbonate, etc. are preferred, and sodium chloride is particularly preferred from the viewpoint of safety, etc.

[0014] (Component (a2) is considered to dissolve in the aqueous phase together with component (a1) to form an equilibrium state. And in that equilibrium state, it is considered that the effects of the present invention are exhibited when the ratio of ions is within a specific range. Here, surprisingly, the effects of the present invention cannot be obtained with alkaline earth metal salts containing calcium or the like, so it is necessary to use alkali metal salts.)

[0015] (The content rate of component (a2) is preferably 0.1 to 1.5% by mass, more preferably 0.2 to 1% by mass, based on the total mass of the two-layer cosmetic.)

[0016] (a3) Water (The cosmetic according to the present invention contains, as a component of the aqueous phase, further water (hereinafter sometimes referred to as component (a3)). As the water, water generally used in cosmetics can be used, for example, purified water, ion-exchanged water, tap water, etc. can be used.)

[0017] (In the cosmetic according to the present invention, component (A) contains the above components (a1) to (a3), and its content rate is preferably 40 to 90% by mass, more preferably 50 to 80% by mass, based on the total mass of the cosmetic.)

[0018] (B) Oil phase (The cosmetic according to the present invention comprises a straight-chain hydrocarbon oil having 6 to 15 carbon atoms (hereinafter sometimes referred to as component (b1)) in the (B) oil phase.)

[0019] (b1) Straight-chain hydrocarbon oil having 6 to 15 carbon atoms In the cosmetic composition according to the present invention, component (b1) is not particularly limited as long as it has 6 to 15 carbon atoms, and can be selected from those commonly used in cosmetics. Examples of straight-chain hydrocarbon oils include mineral oil (liquid paraffin), hydrogenated polyisobutene, isododecane, isohexadecane, squalane, ceresin, and microchrysitalin wax. Of these, hydrocarbon oils selected from the group consisting of mineral oil (liquid paraffin), hydrogenated polyisobutene, isododecane, isohexadecane, and squalane are preferred. Note that component (b1) only needs to have an average number of carbon atoms of 6 to 15, and even if it is a mixture of hydrocarbons outside that range, it is sufficient as long as the average number of carbon atoms is 6 to 15.

[0020] Furthermore, the carbon number of component (b1) is preferably 9 to 12. If component (b1) is a mixture, its average carbon number is preferably 9 to 12. For example, a mixture of hydrocarbons with carbon numbers in the range of 9 to 12 can be suitably used.

[0021] (b2) Other oils The cosmetic composition according to the present invention may contain an oil other than component (b1) (hereinafter sometimes referred to as component (b2)) as component (B). Examples of such oils include alcohol esters, higher fatty acids, and higher alcohols. In the present invention, it is preferable to use an oil selected from the group consisting of hydrocarbon oils, alcohol esters, and silicone oils. However, in the present invention, excellent separation properties can be achieved by balancing component (b1) and the aqueous phase (A), so it is preferable that the content of oils other than component (b1) is not low.

[0022] Even if component (b2) is included, it is preferable that the content of (b1) based on the total mass of component (B) be 85% by mass or more, and more preferably 90% by mass or more.

[0023] In particular, the content of silicone oil in component (B) is preferably low, preferably 1% by mass or less if it is present, and especially preferably no silicone oil is present at all.

[0024] In the cosmetic composition according to the present invention, the content of component (B) is preferably 10 to 60% by mass, and more preferably 20 to 50% by mass, based on the total mass of the cosmetic composition.

[0025] The cosmetic composition according to the present invention may contain ingredients commonly used in cosmetics, other than those mentioned above, as long as they do not impair the effects of the present invention. Examples of such ingredients include thickeners, humectants, water-soluble agents (e.g., arbutin, ascorbic acid glucoside, tranexamic acid, 4-methoxysalicylate, etc.), UV absorbers, chelating agents, pH adjusters, preservatives, pigments, dyes, surfactants, powder components, and the like.

[0026] The cosmetic composition according to the present invention has an excellent appearance in which, upon standing, the aqueous layer and the oil layer clearly separate, each forming a clear, transparent layer. The cosmetic composition, separated into two layers, can be easily and uniformly emulsified by shaking it by hand or the like while still in the container, and then used. After emulsification, the aqueous layer and the oil layer will clearly separate again after being left to stand for a short time, for example, 6 hours or less.

[0027] This two-layer cosmetic composition is not simply separated into two layers; when used, it exhibits the combined advantages of both the aqueous and oil phases. Specifically, by blending appropriate agents into either the aqueous or oil phase, it can be used as a lotion or a cleanser. As a cleanser, the two-layer cosmetic composition according to the present invention can provide a cleansing effect from the oil phase while simultaneously offering a refreshing feel from the aqueous phase.

[0028] [Method of manufacturing cosmetics] The cosmetic composition according to the present invention can be manufactured by blending and mixing each component. The mixing order is not particularly limited, but it is common to prepare the aqueous phase and the oil phase separately and then seal them in a single container. That is, the cosmetic composition can be prepared by preparing the aqueous phase and the oil phase separately and then blending the aqueous phase and the oil phase. [Examples]

[0029] The present invention will be specifically described based on the following examples, but the present invention is not limited to these examples. Unless otherwise specified, the content is expressed in mass percent.

[0030] [Examples 1-7 and Comparative Examples 1-3] Detergents were prepared by combining each component according to the formulations shown in Table 1, and their performance was evaluated. Each evaluation item was assessed using the following method.

[0031] 2 layer formation The cosmetic product was shaken vigorously and then allowed to stand. The separation state was observed and evaluated according to the following criteria. A: It separated into two layers cleanly within 12 hours. B: After more than 12 hours, it separated into two distinct layers. C: Did not separate into two layers

[0032] Irritation The irritation to the eyes during facial cleansing using cosmetics was evaluated according to the following criteria. A: I don't feel any irritation in my eyes. B: It stings my eyes a little. C: Strong eye irritation

[0033] Cleaning power We cleansed the skin using cosmetics and evaluated the cleansing power on a 7-point scale from A (high cleansing power) to G (low cleansing power).

[0034] Refreshing feeling After the cosmetic product was absorbed and evenly distributed, it was applied to the skin and evaluated according to the following criteria based on its feel and performance. A: It has a very refreshing taste. B: It has a refreshing feel. C: Lacks a refreshing taste.

[0035] [Table 1]

Claims

1. (a1) Amphoteric surfactants, (a2) Alkali metal salts and (a3) an aqueous phase (A) comprising water, and (b1) Oil phase (B) comprising a straight-chain hydrocarbon oil having 6 to 15 carbon atoms. A two-layer cosmetic composition containing, A cosmetic in which component (B) does not contain silicone oil, or the silicone oil content based on the total mass of component (B) is 1% by mass or less.

2. (a1) The cosmetic composition according to claim 1, wherein the component is selected from the group consisting of lauryl betaine, cocamidopropyl betaine, and sodium cocoamphoacetate.

3. (a2) The cosmetic composition according to claim 1 or 2, wherein the component is sodium chloride.

4. The cosmetic composition according to claim 1 or 2, wherein the content of (b1) based on the total mass of component (B) is 85% by mass or more.

5. (B) The cosmetic composition according to claim 1 or 2, wherein component (B) consists of a hydrocarbon oil having 9 to 12 carbon atoms.

6. The cosmetic composition according to claim 1 or 2, wherein the content of component (A) is 40 to 90% by mass, and the content of component (B) is 10 to 60% by mass, based on the total mass of the cosmetic composition.

7. The cosmetic composition according to claim 1 or 2, wherein the content of component (a1) is 0.07 to 2% by mass, and the content of component (a2) is 0.1 to 1.5% by mass, based on the total mass of the cosmetic composition.

8. A cosmetic composition according to claim 1 or 2, which is a cleansing agent.

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