Oil-based solid cleansing cosmetics

Abstract

To provide an oily solid cleansing cosmetic blended with a solid oil composition which is excellent in oil solidifying ability in spite of having a low melting point, is excellent in shape holding property and easiness of taking out when formed into an oily solid cleansing cosmetic and has high biodegradability even when released in an environment.SOLUTION: There is provided an oily solid cleansing cosmetic which comprises (A) 1 to 30 mass% of a solid oil having a melting point of 50 to 120°C, (B) 50 to 97 mass% of a liquid oil and (C) 2 to 40 mass% of a nonionic surfactant having an HLB value of 5 to 13 (with a ratio in the total amount of the cosmetic), where the solid oil (A) contains (A-1) behenyl behenate and (A-2) a Fischer-Tropsch wax having a melting point of 50 to 120°C in a mass ratio of (A-1):(A-2)=20:75 to 95:5.SELECTED DRAWING: Figure 1

Description

Technical Field

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[0001] The present invention relates to an oily solid cleansing cosmetic containing a solid oil composition excellent in the solidifying ability of liquid oil.

Background Art

[0002] In recent years, in makeup cosmetics such as lipsticks, foundations, eyeshadows, and mascaras, products excellent in both water resistance and oil resistance have been developed, and the durability of makeup has been remarkably improved. Therefore, when removing the makeup film formed by makeup cosmetics, an oily cleansing cosmetic that is well compatible with makeup (the makeup film on the skin) and has excellent performance in removing dirt such as keratin and sebum (dirt removal ability) is used. Specific examples of oily cleansing cosmetics include cleansing oils, gel状 cleansing agents, cleansing creams, etc. Among them, oily cleansing cosmetics in a solid state at normal temperature have the characteristics of no dripping during use and being easy to massage when making them compatible with makeup, and their development is being actively promoted.

[0003] An oily solid cleansing cosmetic can be obtained by melting a cleansing oil composition together with a solid oil and cooling and solidifying it to form a so-called oil gel. The performance required for the solid oil used includes an oil solidifying ability to solidify liquid oil (also referred to as oil in this specification) with a small amount of formulation, an oil holding ability to prevent the solidified liquid oil from separating, and also the ease of taking out the cosmetic (the ease of crumbling of the oil gel) and good elongation when using the solid oil as an oily solid cosmetic.

[0004] Generally, solid oils with higher melting points have higher oil solidification capabilities. However, using solid oils with high melting points can cause degradation of other components during heating in cosmetic manufacturing. Therefore, there is a demand for solid oils (compositions) with low melting points and high oil solidification capabilities. In particular, oil-based solid cleansing cosmetics have a much larger volume per product (tens of grams to over 100 grams) compared to typical oil-based solid cosmetics such as lipstick, which have a volume of several grams to over 100 grams per product. Because of the longer heating time during bulk manufacturing and filling processes, a low melting point is required for the solid oil to enable manufacturing at lower temperatures. Furthermore, in the case of rinse-off cleansing cosmetics, the components must be highly biodegradable as they are released into wastewater.

[0005] To satisfy these performance requirements, Patent Document 1 proposes a wax composition containing candelilla wax and a monoester with a total of 40 to 48 carbon atoms, and a solid oily cosmetic composition containing this wax composition. However, as will be described later, experiments by the present inventors have shown that the oil solidification ability of the combination of candelilla wax and a monoester with a total of 40 to 48 carbon atoms is still insufficient.

[0006] Patent Document 2 discloses a waxy composition containing (A) a specific polyester and (B1) an ester wax, (B2) a hydrocarbon wax, or (B3) a higher alcohol or higher fatty acid, and also discloses a composition (Claim 4) that simultaneously contains all three wax components (B1), (B2), and (B3). However, there is no disclosure of a wax composition that contains behenyl behenate as the ester wax and Fischer-Tropsch wax as the hydrocarbon wax in specific ratios, and there is no mention at all of the fact that a solid oil composition with excellent oil solidification ability and a low melting point can be obtained by combining these two components.

[0007] Examples 1 to 6 of Patent Document 3 disclose oily solid cleansing cosmetics containing microcrystalline wax or polyethylene wax as the wax. However, due to the high melting point of the wax, there are concerns about the degradation of other components. Furthermore, both microcrystalline wax and polyethylene wax contain many branched hydrocarbons with low biodegradability, leading to environmental pollution problems caused by these components being released into wastewater after rinsing. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] International Publication No. 2018 / 123824 [Patent Document 2] Japanese Patent Publication No. 2018-123117 [Patent Document 3] Japanese Patent Publication No. 2001-213726 [Overview of the project] [Problems that the invention aims to solve]

[0009] The present invention was completed based on the above background technology, and its purpose is to provide an oil-based solid cleansing cosmetic that contains a solid oil composition that has excellent oil solidification ability despite a low melting point, excellent shape retention and ease of removal when used as an oil-based solid cleansing cosmetic, and high biodegradability when released into the environment. [Means for solving the problem]

[0010] Therefore, the inventors diligently conducted research to solve these problems and found that the above requirements could be met by combining behenyl behenate and Fischer-Tropsch wax with a specific melting point in a specific ratio, thus completing the present invention.

[0011] Thus, the present invention provides an oily solid cleansing cosmetic composition containing (A) 1 to 30% by mass of a solid oil having a melting point of 50 to 120°C, (B) 50 to 97% by mass of a liquid oil, and (C) 2 to 40% by mass of a nonionic surfactant having an HLB value of 5 to 13 (percentage of the total amount of the cosmetic composition), wherein the solid oil of (A) contains (A-1) behenyl behenate and (A-2) Fischer-Tropsch wax having a melting point of 50 to 120°C in a mass ratio of (A-1):(A-2)=20:75 to 95:5. [Effects of the Invention]

[0012] The solid oil used in this invention has a low melting point yet possesses high oil solidification ability. Therefore, oil-based solid cleansing cosmetics containing it are easy to manufacture because they do not require high temperatures when heated and melted, have excellent shape retention, and are easy to use because they can be removed smoothly. Furthermore, even when the cosmetic composition of this invention is released into the environment as a cleansing cosmetic, it has a high degree of biodegradability and has little impact on the environment. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is a graph showing the relationship between the mass ratio of behenyl behenate (A-1) / [(A-1)+(A-2)]) to the total of behenyl behenate (A-1) and Fischer-Tropsch wax (A-2) in the example, and the hardness and melting point. [Modes for carrying out the invention]

[0014] (A) Solid oil The solid oil according to the present invention exhibits high oil solidification ability. In this specification, oil solidification ability refers to the ability to solidify liquid oil by forming an oil gel when the solid oil and the remaining cosmetic components, which contain liquid oil at room temperature (25°C), are dissolved at a temperature above the melting point of the solid oil and allowed to cool. The oil solidification ability can be evaluated by measuring the hardness of the oil gel.

[0015] The solid oil content according to the present invention is 1 to 30% by mass in the total amount of the oil-based solid cleansing cosmetic composition, preferably 2 to 25% by mass, and more preferably 3 to 20% by mass. Having a solid oil content within this range allows for good shape retention, stability, and ease of removal during use.

[0016] (A-1) Behenyl behenate The behenyl behenate (component A-1) used in this invention is an ester of behenic acid and behenyl alcohol, with a melting point of 70-75°C, and is a solid oil at room temperature. It is available from Riken Vitamin Co., Ltd., Nisshin Oillio Group, and others. Behenyl behenate alone does not have high oil solidification ability, but surprisingly, when used in combination with Fischer-Tropsch wax (component A-2), it showed higher oil solidification ability than when component A-2 was used alone. On the other hand, the melting point of this mixture did not significantly exceed the melting point predicted from the mixing ratio of components A-1 and A-2. Furthermore, behenyl behenate is expected to exhibit higher biodegradability compared to hydrocarbon-based solidifying agents.

[0017] (A-1) The content of behenyl behenate is preferably 0.5 to 25% by mass, more preferably 0.5 to 20% by mass, and even more preferably 1 to 15% by mass, in the total amount of the oily solid cleansing cosmetic composition of the present invention, as long as it satisfies the range of mass ratios described later. (A-1) Having a behenyl behenate content within this range makes it possible to achieve good shape retention (form retention) and stability as well as ease of removal during use.

[0018] (A-2) Fischer-Tropsch wax with a melting point of 50-120°C The Fischer-Tropsch wax (sometimes referred to as "FT wax" in this specification), component (A-2) used in the present invention, has a melting point of 50 to 120°C and is a synthetic hydrocarbon wax mainly containing linear hydrocarbons. It is synthesized by the Fischer-Tropsch process by reacting an aqueous gas mainly containing carbon monoxide and hydrogen. Furthermore, the website of Cirebelle, the manufacturer of Fischer-Tropsch wax ("WAXES", [online], [searched January 29, 2020], Internet (URL: https: / / cirebelle.com / fine-chemicals / waxes / )), states that Cire wax, which is Fischer-Tropsch wax, is inherently biodegradable. Therefore, even when used as a cleaning agent such as an oily solid cleansing cosmetic, it can be expected to have a smaller environmental impact compared to commonly used polyethylene waxes.

[0019] The melting point of component (A-2) according to the present invention is 50 to 120°C, preferably 60 to 110°C, and more preferably 70 to 100°C. If the melting point is excessively low, the oil solidification ability of the solid oil composition is insufficient, and if it is excessively high, high temperatures are required during the manufacture of the solid oil composition or cosmetic, which can easily cause deterioration of other components. In this specification, the melting points of waxes and solid oil compositions can be measured by the second melting point measurement method, which is a general test method of the Quasi-Drug Raw Material Standards.

[0020] Examples of commercially available Fischer-Tropsch waxes include CIREBELLE 303 (melting point: 51°C), CIREBELLE 305 (melting point: 55°C), CIREBELLE 108 (melting point: 79-84°C), and CIREBELLE 109L (melting point: 91-96°C), all manufactured by CIREBELLE.

[0021] (A-2) The content of Fischer-Tropsch wax with a melting point of 50 to 120 °C is preferably 0.2 to 20% by mass, more preferably 0.2 to 15% by mass, and even more preferably 0.5 to 12% by mass in the total amount of the oily solid cleansing cosmetic of the present invention, as long as it satisfies the range of the mass ratio described below. When the content of the component (A-2) is within this range, good shape retention (morphology maintenance) and stability, and ease of handling during use can be achieved.

[0022] In the solid oil (A) according to the present invention, the ratio of the component (A-1) to the component (A-2) is (A-1):(A-2) = 20:75 to 95:5 by mass ratio, preferably 25:70 to 90:10, and more preferably 30:60 to 80:20. By using both components within this range, the effect of the present invention, that is, a high oil solidification ability can be obtained even when using a solid oil with a low melting point, can be achieved.

[0023] In the solid oil (A) according to the present invention, the total amount of the component (A-1) and the component (A-2) is preferably 50% by mass or more, more preferably 60% by mass or more, based on the total amount of the solid oil (A). If the total amount of the component (A-1) and the component (A-2) is less than 50% by mass, sufficient oil solidification ability cannot be obtained.

[0024] The solid oil (A) according to the present invention may contain (A-3) hydrogenated castor oil in addition to the component (A-1) and the component (A-2). By containing hydrogenated castor oil, the oil retention ability when the oil is solidified can be improved, and bleeding of liquid oil from the oil gel can be prevented. In addition, by containing hydrogenated castor oil, liquid oils with various polarities can be solidified.

[0025] As the hydrogenated castor oil, commercially available products can be used. Examples of the commercially available products include Himar (melting point 86 °C, manufactured by Kawaken Fine Chemical Co., Ltd.), Castor hardened oil A (melting point 85 °C, manufactured by Ito Oil Co., Ltd.), etc. These may be used alone or in combination of two or more.

[0026] The hydrogenated castor oil content is preferably 1 to 50% by mass, more preferably 5 to 40% by mass, relative to the total solid oil (A). Furthermore, the hydrogenated castor oil content is preferably 0.2 to 14% by mass, more preferably 0.5 to 12% by mass, and even more preferably 1 to 10% by mass, relative to the total oily solid cleansing cosmetic composition.

[0027] The oil-based solid cleansing cosmetic of the present invention can be manufactured by separately blending each solid oil component that constitutes (A) the solid oil, but it is preferable to pre-melt and mix the solid oil components homogenously to form a solid oil composition, which is then used in the manufacture of the oil-based solid cleansing cosmetic. For example, the solid oil composition according to the present invention can be manufactured by heating and melting each component at a temperature above its melting point in a predetermined blending ratio, homogenizing it, and then cooling it. This solid oil composition may be molded into any shape, such as flakes or granules, during the cooling process after heating and melting.

[0028] Since the melting point of the solid oil composition is lower than the highest melting point of a single solid oil component, when used in the manufacture of oily solid cleansing cosmetics, incorporating it as a solid oil composition can suppress the deterioration of other components, particularly beauty ingredients such as surfactants and vitamins, due to heating.

[0029] In this specification, for convenience, oils that are solid at room temperature and have a melting point of 50°C or higher are referred to as solid oils, and oils with a melting point below 50°C are referred to as liquid oils. Oils with a melting point between 35°C and 50°C are sometimes referred to as semi-solid oils, but are included in the category of liquid oils.

[0030] The oily solid cosmetic composition of the present invention may contain solid oils other than (A-1), (A-2), and (A-3). Specific examples of such solid oils include hydrocarbon waxes such as paraffin wax, polyethylene wax, ethylene-propylene copolymer, microcrystalline wax, ceresin, and ozokerite; animal and plant waxes such as Japanese wax, carnauba wax, candelilla wax, rice wax, and beeswax; hydrogenated jojoba oil; hydrogenated oil; higher alcohols; and silicone wax. Among the solid oils other than (A-1), (A-2), and (A-3), the use of animal and plant waxes, hydrogenated jojoba oil, hydrogenated oil, and higher alcohols is preferred from the viewpoint of biodegradability. It is preferable not to contain polyethylene wax, microcrystalline wax, ethylene-propylene copolymer, and silicone wax, which have poor biodegradability. Even if they are included, the content is preferably 5% by mass or less, more preferably 2% by mass or less, and even more preferably 1% by mass or less of the total amount of the cosmetic composition.

[0031] (B) Liquid oil The liquid oil (B) used in this invention is an oil that is semi-solid to liquid at room temperature with a melting point of less than 50°C. It is not particularly limited as long as it is an oil commonly used in cosmetics, and may be an animal oil, vegetable oil, or synthetic oil. Specific examples of liquid oils include ethylhexyl palmitate, caprylic / capric triglyceride, triethylhexanoin, dicaprylyl carbonate, diisostearyl malate, diglyceryl triisostearate, decaglyceryl decaisostearate, oligomer esters of dimer acid and dimerol, pentaerythritol tetraisostearate, diglyceryl tetraisostearate, cetyl ethylhexanoate, isopropyl myristate, isopropyl palmitate, octyldodecyl myristate, neopentyl glycol dioctanoate, cholesterol fatty acid esters, jojoba oil, and other esters; volatile isoparaffins, polybutene, polyisobutylene, heavy liquid isoparaffins, liquid paraffins, α-olefin oligomers, squalane, petrolatum, and other hydrocarbons; oils and fats such as olive oil, castor oil, mink oil, and macadamia nut oil; and fatty acids such as isostearic acid and oleic acid. Examples include higher alcohols such as oleyl alcohol and isostearyl alcohol; silicone oils such as low-molecular-weight dimethylpolysiloxane, cyclic silicone, high-molecular-weight dimethylpolysiloxane, methylphenylpolysiloxane, methyl trimethicone, caprylyl trimethicone, cross-linked organopolysiloxane, and fluorine-modified polysiloxane; fluorinated oils such as perfluoropolyethers; and lanolin derivatives such as lanolin, lanolin acetate, isopropyl lanolin fatty acid, and lanolin alcohol.

[0032] From the viewpoint of makeup removal and ease of rinsing, the use of esters is preferred, and ethylhexyl palmitate, caprylic / capric triglyceride, triethylhexanoin, and dicaprylyl carbonate are preferably used.

[0033] In the total amount of the oil-based solid cleansing cosmetic, the content of (B) liquid oil is 50 to 97% by mass, preferably 55 to 95% by mass, and more preferably 60 to 92% by mass. Having a liquid oil content within this range allows for good shape retention, stability, and ease of removal during use.

[0034] (C) Nonionic surfactant In the oil-based solid cleansing cosmetic composition of the present invention, a nonionic surfactant having an HLB value in the range of 5 to 13 is used as component (C). Here, "nonionic surfactant having an HLB value in the range of 5 to 13" means one type of nonionic surfactant having an HLB value in the range of 5 to 13, a combination of multiple nonionic surfactants having HLB values ​​in that range, or a combination of multiple nonionic surfactants whose weighted average HLB value is in the range of 5 to 13 as a result of combining two or more nonionic surfactants with different HLB values.

[0035] HLB is an index that indicates the balance between hydrophilicity and lipophilicity on a scale of 0 to 20, with values ​​closer to 0 indicating higher lipophilicity and values ​​closer to 20 indicating higher hydrophilicity. Various calculation methods are known for determining HLB values, and the values ​​are also listed in catalogs provided by manufacturers. In this specification, if the nonionic surfactant is a commercially available product, the HLB value listed in the manufacturer's catalog is used. If it is not a commercially available product, the value calculated using Griffin's method (HLB value = 20 × sum of formula weights of hydrophilic parts / molecular weight) as described on page 307 of the "Surfactant Handbook" (published by Sangyo Tosho Co., Ltd., 1960) is used.

[0036] If the HLB value of the nonionic surfactant is less than 5, even if you try to rinse off makeup with water or lukewarm water after applying the cleansing cosmetic to the skin, it will not rinse off cleanly due to poor compatibility with water, and you will not get the refreshing feeling after rinsing. Conversely, if the HLB value exceeds 13, hydrophobic makeup will not be able to be applied to the cleansing cosmetic, resulting in insufficient makeup removal. Among these, an HLB value in the range of 6 to 11 provides good makeup removal and ease of rinsing. The nonionic surfactant in component (C) may be in solid or liquid form, but using a liquid nonionic surfactant at 25°C will provide better performance in terms of makeup removal and ease of rinsing.

[0037] (C) Nonionic surfactants with an HLB value of 5 to 13 used as component, and specific examples of nonionic surfactants whose HLB value falls within the above range when used in combination include: polyglyceryl-4 stearate, polyglyceryl-2 oleate, polyglyceryl-2 isostearate, polyglyceryl-10 distearate, and other polyglycerin fatty acid esters; polyoxyethylene hydrogenated castor oils such as PEG-10 hydrogenated castor oil and PEG-20 hydrogenated castor oil; polyoxyethylene fatty acid esters such as PEG-2 stearate and PEG-5 stearate; polyoxyethylene alkyl ethers such as ceteth-2, oleth-3, and steareth-6; fatty acid polyoxyethylene alkyl ethers such as steareth-6 stearate, laureth-8 isostearate, and steareth-12 stearate; Examples include polyoxyethylene fatty acid glyceryls such as PEG-3 glyceryl isostearate, PEG-15 glyceryl tristearate, PEG-5 glyceryl triisostearate, PEG-10 glyceryl triisostearate, PEG-20 glyceryl triisostearate, and PEG-20 glyceryl tristearate; and fatty acid polyoxyethylene hydrogenated castor oils such as PEG-15 hydrogenated castor oil isostearate and PEG-20 hydrogenated castor oil triisostearate. Other examples include sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene polyoxypropylene copolymers, ethers of polyoxyethylene polyoxypropylene copolymers and long-chain alcohols, and ethers of polybutylene glycol polyglycerin copolymers and long-chain alcohols. Among these, polyoxyethylene fatty acid esters, polyoxyethylene fatty acid glyceryls, fatty acid polyoxyethylene hydrogenated castor oils, and fatty acid polyoxyethylene alkyl ethers are preferred from the viewpoint of makeup removal and ease of washing.

[0038] (C) When the nonionic surfactant used as component has a fatty acid residue in its molecule, the fatty acid residue is preferably a higher fatty acid having 10 to 22 carbon atoms, such as myristic acid, palmitic acid, stearic acid, isostearic acid, or oleic acid. In particular, the nonionic surfactant is preferably a branched higher fatty acid residue that results in a liquid state and excellent oxidation resistance stability, and isostearic acid residue is especially preferred.

[0039] (C) Examples of commercially available nonionic surfactants that are liquid at 25°C and used as an ingredient include Emarex RWIS-320 (PEG-20 hydrogenated castor oil triisostearate; manufactured by Nippon Emulsion Co., Ltd.; HLB value 6), Emarex GWIS-305 (PEG-5 glyceryl triisostearate; manufactured by Nippon Emulsion Co., Ltd.; HLB value 3), Uniox GT-20IS (PEG-20 glyceryl triisostearate; manufactured by NOF Corporation; HLB value 10.4), etc. Examples of commercially available solid products at 25°C include Emarex GWS-320 (PEG-20 glyceryl tristearate; manufactured by Nippon Emulsion Co., Ltd.; HLB value 8), Emarex SWS-12 (Steareth-12 stearate; manufactured by Nippon Emulsion Co., Ltd.; HLB value 8) Examples include Emarex 608 (Steareth-8; manufactured by Nippon Emulsion Co., Ltd.; HLB value 9). Note that Emarex GWIS-305 has a low HLB value and is therefore used in combination with other nonionic surfactants.

[0040] The amount of ingredient (C) used is 2 to 40% by mass, preferably 4 to 35% by mass, more preferably 5 to 30% by mass, and particularly preferably 7 to 25% by mass, of the total amount of oil-based solid cleansing cosmetic. If this amount is too low, makeup removal and ease of rinsing will decrease, and if it is too high, skin irritation may be a concern.

[0041] The oil-based solid cleansing cosmetic composition of the present invention may contain a small amount of water. Preferably, the water content is 5% by mass or less of the total cosmetic composition. Within this range, the nonionic surfactant of component (C) and water are in a solubilized state, that is, the oily component is present as a dispersion medium, and component (C) and water form reverse micelles. As a result, the nonionic surfactant of component (C) becomes more easily soluble in the oil, and separation or precipitation of component (C) does not occur even during long-term storage, improving storage stability. This effect is particularly pronounced when the water content is 0.1 to 3% by mass.

[0042] The oil-based solid cleansing cosmetic composition of the present invention may contain additives such as powders, dyes, oil-based gelling agents, oil-soluble resins, polyhydric alcohols, lower alcohols, UV absorbers, UV scattering agents, humectants, fragrances, antioxidants, preservatives, defoaming agents, beauty ingredients, and various extracts, to the extent that they do not impair the effects of the present invention.

[0043] The oil-based solid cleansing cosmetic of the present invention does not exhibit fluidity at room temperature (25°C) and atmospheric pressure (1 atm), and its shape is not particularly limited. Specific examples of shapes include stick-shaped, rod-shaped, plate-shaped, and those formed by pouring into a container. These various cleansing cosmetic compositions can be prepared according to conventional methods. For example, all raw materials can be heated above their melting point, mixed uniformly, poured into a container or mold while still molten, and then cooled or allowed to cool to obtain an oil-based solid cleansing cosmetic.

[0044] A preferred manufacturing method includes the step of uniformly melting and mixing (A) solid oil containing components (A-1) and (A-2) at a temperature above its melting point to form a solid oil composition, and then melting and mixing the solid oil composition with other components including (B) liquid oil. By adopting such a manufacturing method, it is possible to prepare the product while preventing the deterioration of heat-sensitive components such as (C) surfactants and beauty ingredients such as vitamins. When manufacturing an oily solid cleansing cosmetic using a solid oil composition, it is preferable to manufacture it at a temperature of 85°C or lower, and more preferably at a temperature of 82°C or lower.

[0045] The oil-based solid cleansing cosmetic of the present invention possesses not only the function of removing makeup but also the characteristics required of a massage cosmetic, namely, appropriate viscosity, slipperiness, and persistence of slipperiness. Therefore, it can be used as a massage cosmetic in addition to being used as an oil-based solid cleansing cosmetic of the present invention. When using the oil-based solid cleansing cosmetic of the present invention, the makeup can be removed by applying the cosmetic to the makeup and then rinsing it off with water or lukewarm water. Therefore, it is possible to omit the facial cleansing step with soap or other facial cleanser that was considered necessary after using conventional oil-based solid cleansing cosmetics. [Examples]

[0046] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. Unless otherwise specified, the amounts of each component in the compositions described below are expressed as mass percent of the total amount.

[0047] <Solid oil composition> The evaluation method for the solid oil composition according to the present invention in the following manufacturing examples and comparative manufacturing examples is as follows.

[0048] (Melting point) Melting point measurement method No. 2, a general test method for quasi-drug raw material standards. (hardness) 94 parts by mass of the cleansing oil with the composition shown in Table 1 and 6 parts by mass of each solid oil composition from the examples and comparative examples were heated and mixed at 90°C until uniformly dissolved. Then, while still at 90°C, 50 g of the composition was poured into a cylindrical polypropylene container with an inner diameter of 56 mm and allowed to cool overnight in a constant temperature bath at 25°C to form an oil gel. The hardness of the oil gel was then measured using the method described below. Using a Sunrometer CR-100 (manufactured by Sun Science Co., Ltd.), the needle was inserted to a depth of 10 mm at a maximum stress range of 2 KG using a 10 mm diameter disc needle adapter at a needle insertion speed of 20 mm / min. The average stress at a needle insertion depth of 2 to 8 mm was defined as the hardness (gf).

[0049] Cleansing oil formula [Table 1] *1: Product name: Uniox GT20-IS (manufactured by NOF Corporation) *2: Product name: Emarex GWIS-305 (manufactured by Nippon Emulsion Co., Ltd.) * In Table 1, the weighted average HLB value for nonionic surfactants is 9.475.

[0050] (Manufacturing Examples 1-5, Comparative Manufacturing Examples 1-5) Solid oil compositions with the compositions shown in Table 2 were manufactured according to the following manufacturing method. The melting point of the solid oil composition and the hardness of the oil gel obtained by heating and melting the solid oil composition with the cleansing oil shown in Table 1 and then allowing it to cool were evaluated using the method described above. The evaluation results are shown in Table 2. Figure 1 shows graphs illustrating the relationship between the ratio of behenyl behenate (A-1) to Fischer-Tropsch wax (A-2) (A-1) / [(A-1)+(A-2)] (mass%), hardness, and melting point for manufacturing examples 1 to 4 and comparative manufacturing examples 1 to 3.

[0051] (Manufacturing method) The solid oils with the compositions shown in Table 2 were melted at 95°C, uniformly mixed, and then allowed to cool to room temperature to obtain the solid oil composition.

[0052] [Table 2] *3: Product name: CIREBELLE 108 (manufactured by CIREBELLE) *4: Product name PERFORMALENE500 (manufactured by Newphase Technology Inc.)

[0053] As is clear from Figure 1, the melting point of the solid oil composition, which is a mixture of components (A-1) and (A-2), was close to the weighted average of the individual melting points of components (A-1) and (A-2). However, the hardness of the oil gel produced by the mixture solid oil composition was significantly higher than the value predicted from the hardness of the individual components. In particular, in the range of ratio (A-1) / [(A-1)+(A-2)] (mass%) from 20 / 95 to 95 / 100, it can be seen that high hardness can be obtained despite a low melting point. Comparative production example 4, in which Fischer-Tropsch wax in production example 3 was replaced with commonly used polyethylene wax, had a high melting point and lower oil gel hardness compared to production example 3. In comparative production example 5, the combination of behenyl behenate and candelilla wax yielded only extremely low oil gel hardness. The solid oil composition of production example 5, which contains hydrogenated castor oil, also showed a low melting point and high oil solidification ability.

[0054] <Oil-based solid cleansing cosmetic> The evaluation method for the oil-based solid cleansing cosmetic composition of the present invention in the following examples and comparative examples is as follows.

[0055] (hardness) The sample was heated and dissolved at 90°C, 50g of the cosmetic was poured into a cylindrical polypropylene container with an inner diameter of 56mm, and allowed to cool overnight in a constant temperature bath at 25°C. The hardness (gf) was then measured using the method described below. Using a Sunrometer CR-100 (manufactured by Sun Science Co., Ltd.), the needle was inserted to a depth of 10 mm at a maximum stress range of 2 KG using a 10 mm diameter disc needle adapter, at a needle insertion speed of 20 mm / min. The average stress at a needle insertion depth of 2 to 8 mm was defined as the hardness.

[0056] (Mold retention) The hardness values ​​were used to determine the hardness according to the following criteria. A:Hardness 300 or more B: Hardness between 200 and 300 C: Hardness between 100 and 200 D: Hardness less than 100

[0057] (Ease of spreading, effectiveness in removing makeup, ease of rinsing) Ten female evaluators with makeup experience applied commercially available powder foundation (Cezanne Cosmetics Co., Ltd., Cezanne UV Foundation EX Plus) to their skin, then cleansed it using an evaluation sample. For each item, they scored it on a 5-point scale from 1 to 5 based on the evaluation criteria shown in (1) below. The average score of the 10 evaluators was calculated, and the performance of the cleansing cosmetic was determined according to the 4-point evaluation criteria shown in (2) below.

[0058] (1) Evaluation Criteria 5 points: Good 4 points: Fairly good 3 points: Can't say either way. 2 points: Slightly bad 1 point: Bad

[0059] (2) Four-stage evaluation criteria A: Average score between 4 and 5 B: Average score between 3 and 4 C: Average score between 2 and 3 D: Average score is less than 2

[0060] Examples 1-3 and Comparative Examples 1-4 (Oil-based solid cleansing cosmetic) Oil-based solid cleansing cosmetics with the formulations shown in Table 3 were prepared according to the following manufacturing procedure. The obtained oil-based solid cleansing cosmetics were evaluated for hardness, shape retention, uniformity, spreadability, makeup removal effectiveness, and ease of rinsing using the method described above. The evaluation results are shown in Table 3.

[0061] (Manufacturing procedure) (1) Heat components 1 to 14 shown in Table 3 to 82°C and mix them uniformly. (2) Fill the mixture prepared in (1) above into a jar container at 70°C while still in a molten state, and then allow it to cool to obtain an oil-based solid cleansing cosmetic.

[0062] [Table 3]

[0063] The results in Table 3 show that the oil-based solid cleansing cosmetics of Examples 1-3 had sufficient shape retention for easy portability and formed a uniform oil gel even at a relatively mild manufacturing temperature of 82°C. They also exhibited excellent spreadability, makeup removal effectiveness, and ease of rinsing. In contrast, the cosmetics of Comparative Example 1, which contained only Fischer-Tropsch wax without behenyl behenate as the solid oil component, and Comparative Example 2, which contained polyethylene wax, could not be completely melted at the same manufacturing temperature and failed to form a uniform oil gel, resulting in low hardness and insufficient shape retention. The cosmetic of Comparative Example 3, which contained candelilla wax and behenyl behenate as the solid oil components, had insufficient shape retention. The cosmetic of Comparative Example 4, which did not contain a nonionic surfactant, had inferior makeup removal and rinsing performance. [Industrial applicability]

[0064] According to the present invention, an oil-based solid cleansing cosmetic is provided that has excellent cleansing performance, is easy to manufacture, and is also highly biodegradable.

Claims

1. An oil-based solid cleansing cosmetic containing 1 to 30% by mass of (A) a solid oil having a melting point of 50 to 120°C, 50 to 97% by mass of (B) a liquid oil, and 2 to 40% by mass of (C) a nonionic surfactant having an HLB value of 5 to 13 (proportion of the total amount of the cosmetic), wherein the solid oil (A) contains (A-1) behenyl behenate and (A-2) a Fischer-Tropsch wax having a melting point of 50 to 120°C in a mass ratio of (A-1):(A-2) = 20:75 to 95:

5.

2. 2. The oil-based solid cleansing cosmetic according to claim 1, wherein the sum of the contents of the components (A-1) and (A-2) in the solid oil (A) is 50% by mass or more relative to the total amount of the solid oil (A).

3. 3. The oil-based solid cleansing cosmetic according to claim 1, wherein the solid oil (A) further contains (A-3) hydrogenated castor oil in an amount of 1 to 50% by mass based on the total mass of the solid oil (A).

4. 4. The oily solid cleansing cosmetic according to claim 1, comprising 0.5 to 25% by mass of component (A-1) and 0.2 to 20% by mass of component (A-2) relative to the total mass of the cosmetic.

5. A method for producing an oily solid cleansing cosmetic, comprising the step of melting a solid oil composition containing (A-1) behenyl behenate and (A-2) a Fischer-Tropsch wax having a melting point of 50 to 120°C in a mass ratio of (A-1):(A-2) = 20:75 to 95:5 together with a liquid oil.

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