JP7668476B2 - Oil-based solid cleansing cosmetics - Google Patents

Description

The present invention relates to an oil-based solid cleansing cosmetic that contains a solid oil composition that has excellent ability to solidify liquid oil.

In recent years, makeup cosmetics such as lipstick, foundation, eye shadow, and mascara have been developed that are both water-resistant and oil-resistant, and the makeup wear time has been significantly improved. Therefore, when removing the makeup film created by makeup cosmetics, oil-based cleansing cosmetics are used that blend well with makeup (the makeup film on the skin) and have excellent performance (stain removal ability) in removing dirt such as keratin and sebum. Specific examples of oil-based cleansing cosmetics include cleansing oil, gel-type cleansing agents, and cleansing creams. Among these, oil-based cleansing cosmetics that are solid at room temperature have the advantage of not dripping during use and being easy to massage when blending with makeup, and their development is being actively pursued.

An oil-based solid cleansing cosmetic can be obtained by melting a cleansing oil composition together with a solid oil, and then cooling and solidifying it to form a so-called oil gel. The performance required of the solid oil used is an oil solidification ability that allows a small amount of the composition to solidify liquid oil (also referred to as oil in this specification), an oil retention ability that prevents the solidified liquid oil from separating, and ease of removal of the cosmetic (ease of crumbling of the oil gel) and good spreadability when the solid oil is used to make an oil-based solid cosmetic.

In general, the higher the melting point of a solid oil, the higher its oil solidification ability. However, the use of a solid oil with a high melting point causes the deterioration of other ingredients when heated during the manufacture of cosmetics, so there is a demand for solid oils (compositions) with low melting points and high oil solidification ability. In particular, oil-based solid cleansing cosmetics have a large volume per product, ranging from tens of grams to hundreds of grams, compared to a few grams to a dozen grams per product of makeup cosmetics such as lipstick, which are typical oil-based solid cosmetics. Since the heating time during bulk production and filling processes is long, it is required that the solid oil have a low melting point so that production at lower temperatures is possible. Furthermore, in the case of washable cleansing cosmetics, etc., they are released into domestic wastewater, so they are also required to be highly biodegradable components.

In order to meet such performance requirements, Patent Document 1 proposes a wax composition containing candelilla wax and a monoester having a total of 40 to 48 carbon atoms, and a solid oil-based cosmetic composition containing said wax composition. However, as described below, according to experiments conducted by the present inventors, the oil solidification ability of the combination of candelilla wax and a monoester having a total of 40 to 48 carbon atoms was still insufficient.

Patent Document 2 discloses a wax-like 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) containing the three wax components (B1), (B2), and (B3) simultaneously. However, there is no disclosure of a wax composition containing behenyl behenate as the ester wax and Fischer-Tropsch wax as the hydrocarbon wax in a specific ratio, 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.

Examples 1 to 6 of Patent Document 3 disclose oil-based solid cleansing cosmetics that contain microcrystalline wax or polyethylene wax as the wax, but because the wax has a high melting point, there are concerns that other ingredients may deteriorate, and because both microcrystalline wax and polyethylene wax contain a large amount of branched hydrocarbons that have low biodegradability, there is a problem of environmental pollution caused by these ingredients being released into domestic wastewater after rinsing.

International Publication No. 2018/123824 JP 2018-123117 A JP 2001-213726 A

The present invention was completed against this background, 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 its low melting point, excellent shape retention and ease of removal when made into an oil-based solid cleansing cosmetic, and is highly biodegradable even when released into the environment.

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

Thus, according to the present invention, there is provided an oil-based solid cleansing cosmetic that contains (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 (proportion of the total amount of the cosmetic) of a nonionic surfactant having an HLB value of 5 to 13, wherein the solid oil (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.

The solid oil used in the present invention has a low melting point and high oil solidification ability. Therefore, an oil-based solid cleansing cosmetic containing this is easy to manufacture since it does not require high temperatures when heated and melted, has excellent shape retention, and is easy to use since it can be removed smoothly. Furthermore, the cosmetic of the present invention is highly biodegradable and has little impact on the environment even when released into the environment as a cleansing cosmetic.

FIG. 1 is a graph showing the relationship between the mass ratio of behenyl behenate (A-1) to the total of behenyl behenate (A-1) and Fischer-Tropsch wax (A-2) ((A-1)/[(A-1)+(A-2)]) and hardness and melting point in the examples.

(A) Solid Oil The solid oil according to the present invention exhibits high oil solidification ability. In this specification, the term "oil solidification ability" refers to the ability to generate an oil gel and solidify the liquid oil when the solid oil and the remaining cosmetic ingredients, including the oil that is liquid at room temperature (25°C), are dissolved at a temperature equal to or higher than the melting point of the solid oil and allowed to cool, and the oil solidification ability can be evaluated by measuring the hardness of the oil gel.

The content of the solid oil according to the present invention in the total amount of the oil-based solid cleansing cosmetic is 1 to 30% by mass, preferably 2 to 25% by mass, and more preferably 3 to 20% by mass. By having the solid oil content within this range, it is possible to achieve good shape retention (shape retention) and stability, as well as ease of removal during use.

(A-1) Behenyl Behenate The behenyl behenate of the component (A-1) used in the present invention is an ester of behenic acid and behenyl alcohol, has a melting point of 70 to 75°C, and is a solid oil at room temperature. It is available from Riken Vitamin Co., Ltd., Nisshin Oillio Group, Inc., and the like. Behenyl behenate alone does not have a high oil solidification ability, but surprisingly, when used in combination with the Fischer-Tropsch wax of the component (A-2), it showed a higher oil solidification ability than when the component (A-2) was used alone. Meanwhile, the melting point of this mixture was not significantly higher than the melting point predicted from the mixture ratio of the components (A-1) and (A-2). In addition, behenyl behenate is expected to show higher biodegradability than hydrocarbon solidifiers.

The content of (A-1) 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, of the total amount of the oil-based solid cleansing cosmetic composition of the present invention, as long as the range of mass ratios described below is satisfied. By having the content of (A-1) behenyl behenate within this range, good shape retention (shape retention) and stability, as well as ease of removal during use, can be achieved.

(A-2) Fischer-Tropsch wax having a melting point of 50 to 120° C. The Fischer-Tropsch wax having a melting point of 50 to 120° C. (sometimes referred to as "FT wax" in this specification) which is the component (A-2) used in the present invention is a synthetic hydrocarbon wax containing mainly linear hydrocarbons, and is synthesized by the Fischer-Tropsch process by reacting water gas containing carbon monoxide and hydrogen as main components. Furthermore, the website of Cirebelle, a manufacturer of Fischer-Tropsch wax ("WAXES", [online], [searched January 29, 2020], Internet (URL: https://cirebelle.com/fine-chemicals/waxes/)) describes that Cire wax, which is a Fischer-Tropsch wax, is inherently biodegradable, and therefore, even when used in cleaning agents such as oil-based solid cleansing cosmetics, it is expected to have a smaller environmental impact than commonly used polyethylene waxes.

The melting point of the 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 too low, the oil solidification ability of the solid oil composition is insufficient, and if it is too high, high temperatures are required during the production of the solid oil composition or cosmetic product, which is likely to cause deterioration of other ingredients. In this specification, the melting points of the wax and solid oil composition can be measured by Melting Point Measurement Method 2, which is a general test method in the Quasi-Drug Raw Materials Standards.

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.

The content of (A-2) Fischer-Tropsch wax having 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, of the total amount of the oil-based solid cleansing cosmetic composition of the present invention, as long as the range of mass ratios described below is satisfied. By having the content of component (A-2) within this range, good shape retention (shape retention) and stability as well as ease of removal during use can be achieved.

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

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

The solid oil (A) according to the present invention can contain (A-3) hydrogenated castor oil in addition to the components (A-1) and (A-2). By containing hydrogenated castor oil, the oil retention ability when the oil is solidified can be improved, and the seepage of liquid oil from the oil gel can be prevented. Furthermore, by containing hydrogenated castor oil, liquid oils of various polarities can be solidified.

As the hydrogenated castor oil, commercially available products can be used, and examples of the commercially available products include Castor Hard Oil (melting point 86°C, manufactured by Kawaken Fine Chemicals Co., Ltd.) and Castor Hardened Oil A (melting point 85°C, manufactured by Ito Oil Mills Co., Ltd.). These may be used alone or in combination of two or more types.

The content of hydrogenated castor oil is preferably 1 to 50% by mass, and more preferably 5 to 40% by mass, based on the total solid oil (A). The content of hydrogenated castor oil is preferably 0.2 to 14% by mass, and more preferably 0.5 to 12% by mass, and even more preferably 1 to 10% by mass, based on the total oil-based solid cleansing cosmetic.

Although the oil-based solid cleansing cosmetic of the present invention can be produced by mixing the solid oil components constituting the solid oil (A) separately, it is preferable to homogenously melt and mix the solid oil components in advance and provide the solid oil composition for producing the oil-based solid cleansing cosmetic. For example, the solid oil composition of the present invention can be produced by heating and melting the components at a predetermined blending ratio at a temperature equal to or higher than the melting point of each component, homogenizing the components, and then cooling the components. This solid oil composition may be molded into any shape, such as flakes or granules, when cooled after being heated and melted.

The melting point of the solid oil composition is lower than the highest melting point of a single solid oil component, so when producing an oil-based solid cleansing cosmetic, by incorporating it as a solid oil composition, it is possible to suppress the deterioration of other components other than the solid oil, particularly beauty ingredients such as surfactants and vitamins, due to heating.

For the sake of convenience, in this specification, 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 of less than 50°C are referred to as liquid oils. Oils with a melting point of 35°C or higher and less than 50°C are sometimes referred to as semi-solid oils, but are included in the category of liquid oils.

The oil-based solid cosmetic 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 vegetable waxes such as japan wax, carnauba wax, candelilla wax, rice wax and beeswax (beeswax), hydrogenated jojoba oil, hardened oils, higher alcohols and silicone waxes. Among the solid oils other than (A-1), (A-2) and (A-3), animal and vegetable waxes, hydrogenated jojoba oil, hardened oils and higher alcohols are preferred from the viewpoint of biodegradability. It is preferable not to contain polyethylene wax, microcrystalline wax, ethylene-propylene copolymer and silicone wax, which are poorly biodegradable. Even if they are contained, the content is preferably 5% by mass or less of the total amount of the cosmetic, more preferably 2% by mass or less, and even more preferably 1% by mass or less.

(B) Liquid Oil The (B) liquid oil used in the present invention is an oil component that is semi-solid to liquid at room temperature and has a melting point of less than 50° C. There are no particular limitations on the type of oil, so long as it is one that is commonly used in cosmetics, and it may be any of animal oils, vegetable oils, and synthetic oils. Specific examples of liquid oils include esters such as ethylhexyl palmitate, tri(caprylic/capric acid)glyceryl, triethylhexanoin, dicaprylyl carbonate, diisostearyl malate, diglyceryl triisostearate, decaglyceryl decaisostearate, oligomer esters of dimer acid and dimer diol, pentaerythritol tetraisostearate, diglyceryl tetraisostearate, cetyl ethylhexanoate, isopropyl myristate, isopropyl palmitate, octyldodecyl myristate, neopentyl glycol dioctanoate, cholesterol fatty acid esters, and jojoba oil; hydrocarbons such as volatile isoparaffin, polybutene, polyisobutylene, heavy liquid isoparaffin, liquid paraffin, α-olefin oligomer, squalane, and petrolatum; oils and fats such as olive oil, castor oil, mink oil, and macadamia nut oil; fatty acids such as isostearic acid and oleic acid; Higher alcohols such as oleyl alcohol and isostearyl alcohol; silicone oils such as low polymerization degree dimethylpolysiloxane, cyclic silicone, high polymerization degree dimethylpolysiloxane, methylphenylpolysiloxane, methyltrimethicone, caprylyl trimethicone, crosslinked organopolysiloxane, and fluorine-modified polysiloxane; fluorine-based oils such as perfluoropolyether; lanolin derivatives such as lanolin, lanolin acetate, lanolin fatty acid isopropyl, and lanolin alcohol; and the like.

The use of esters is preferred in terms of the ability to remove makeup stains and ease of rinsing, with ethylhexyl palmitate, tri(caprylic/capric acid)glyceryl, triethylhexanoin, and dicaprylyl carbonate being preferred.

The content of (B) liquid oil in the total amount of the oil-based solid cleansing cosmetic is 50 to 97% by mass, preferably 55 to 95% by mass, and more preferably 60 to 92% by mass. By having the liquid oil content within this range, good shape retention (shape retention) and stability as well as ease of removal during use can be achieved.

(C) Nonionic Surfactant In the oil-based solid cleansing cosmetic of the present invention, a nonionic surfactant having an HLB value in the range of 5 to 13 is used as component (C). Here, "a 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 in which the 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.

HLB is an index showing the balance between hydrophilicity and lipophilicity, with a value between 0 and 20, with the closer to 0 the higher the lipophilicity, and the closer to 20 the higher the hydrophilicity. Various methods are known for calculating the HLB value, and the value is listed in the catalogue provided by the manufacturer. In this specification, the HLB value of a nonionic surfactant is the HLB value listed in the manufacturer's catalogue if the nonionic surfactant is a commercially available product, and if the surfactant is not a commercially available product, the value calculated by the Griffin method (HLB value = 20 x sum of formula weights of hydrophilic parts / molecular weight) listed on page 307 of "Surfactant Handbook" (published by Sangyo Tosho Co., Ltd., 1960) is used.

If the HLB value of the nonionic surfactant is less than 5, even if makeup is applied to the skin with the cleansing cosmetic and then rinsed off with water or lukewarm water, it will not be able to be washed off cleanly due to poor compatibility with water, and no refreshing feeling will be obtained after rinsing. Conversely, if the HLB value exceeds 13, hydrophobic makeup will not be able to be applied to the cleansing cosmetic, and makeup removal will be insufficient. Among these, an HLB value in the range of 6 to 11 provides good makeup removal and ease of rinsing. The nonionic surfactant of component (C) may be either solid or liquid, but the use of a nonionic surfactant that is liquid at 25°C provides better performance in terms of makeup removal and ease of rinsing off.

Specific examples of nonionic surfactants having an HLB value of 5 to 13 used as component (C), and nonionic surfactants whose HLB value falls within the above range when used in combination, include polyglycerin fatty acid esters such as polyglyceryl-4 stearate, polyglyceryl-2 oleate, polyglyceryl-2 isostearate, and polyglyceryl-10 distearate; 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 of the fatty acid include polyoxyethylene glyceryl fatty acids 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; fatty acid polyoxyethylene hydrogenated castor oils such as PEG-15 hydrogenated castor oil isostearate and PEG-20 hydrogenated castor oil triisostearate; and the like. 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 glyceryl, fatty acid polyoxyethylene hydrogenated castor oil, and fatty acid polyoxyethylene alkyl ethers are preferably used from the viewpoints of makeup removal and ease of rinsing.

When the nonionic surfactant used as component (C) has a fatty acid residue in the molecule, the fatty acid residue is preferably a residue of a higher fatty acid having 10 to 22 carbon atoms, such as myristic acid, palmitic acid, stearic acid, isostearic acid, oleic acid, etc., and among these, it is preferable that the nonionic surfactant be a residue of a branched higher fatty acid that has excellent oxidation stability and is in a liquid state, and isostearic acid residue is particularly preferable.

Commercially available nonionic surfactants that are liquid at 25°C and are used as component (C) include, for example, Emalex RWIS-320 (PEG-20 hydrogenated castor oil triisostearate; manufactured by Nippon Emulsion Co., Ltd.; HLB value 6), Emalex GWIS-305 (PEG-5 glyceryl triisostearate; manufactured by Nippon Emulsion Co., Ltd.; HLB value 3), and Uniox GT-20IS (PEG-20 glyceryl triisostearate; manufactured by NOF Corp.; HLB value 10.4), and commercially available products that are solid at 25°C include, for example, Emalex GWS-320 (PEG-20 glyceryl triisostearate; manufactured by Nippon Emulsion Co., Ltd.; HLB value 8), Emalex SWS-12 (steareth-12 stearate; manufactured by Nippon Emulsion Co., Ltd.; HLB value 8), Emalex 608 (Steareth-8; Nippon Emulsion Co., Ltd.; HLB value 9), etc. Emalex GWIS-305 has a low HLB value and is therefore used in combination with other nonionic surfactants.

The amount of component (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, based on the total amount of the oil-based solid cleansing cosmetic. If this amount is too small, makeup removal and ease of rinsing will decrease, and if it is too large, there is concern that it may cause irritation to the skin.

The oil-based solid cleansing cosmetic of the present invention may contain a small amount of water. The water content is preferably 5% by mass or less of the entire cosmetic, and within this range, the nonionic surfactant of component (C) and water are in a solubilized state, that is, the oil component exists as a dispersion medium, and component (C) and water form a reverse micelle. As a result, the nonionic surfactant of component (C) is easily dissolved in the oil agent, and separation or precipitation of component (C) does not occur even during long-term storage, improving storage stability. In particular, when the water content is 0.1 to 3% by mass, the effect is remarkable.

The oil-based solid cleansing cosmetic of the present invention can contain additives such as ingredients used in ordinary cosmetics, such as powders, dyes, oil-based gelling agents, oil-soluble resins, polyhydric alcohols, lower alcohols, ultraviolet absorbers, ultraviolet scattering agents, moisturizing agents, fragrances, antioxidants, preservatives, defoamers, cosmetic ingredients, and various extracts, within the range that does not impair the effects of the present invention.

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

A preferred production method includes a process in which (A) solid oil containing components (A-1) and (A-2) is homogeneously melt-mixed in advance at a temperature equal to or higher than the melting point to form a solid oil composition, and the solid oil composition is melt-mixed with other components containing (B) liquid oil. By using such a production method, it is possible to prepare the product while preventing deterioration of components (C) that are sensitive to heat, such as surfactants and beauty ingredients such as vitamins. When producing an oil-based solid cleansing cosmetic product using a solid oil composition, it is preferable to produce the product at a temperature of 85°C or lower, and more preferably at a temperature of 82°C or lower.

In addition to the function of removing makeup, the oil-based solid cleansing cosmetic of the present invention has the properties required for a massage cosmetic, namely, appropriate viscosity, slipperiness, and persistence of slipperiness. Therefore, it can be used as a massage cosmetic in addition to the 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 blending the cosmetic with the makeup and then rinsing it off with water or lukewarm water. Therefore, when using conventional oil-based solid cleansing cosmetics, it is possible to omit the face washing operation with a face wash such as soap, which was thought to be necessary after use.

The present invention will be explained in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. In the following description, the blending amounts in the composition are expressed as mass % of the total amount unless otherwise specified.

<Solid Oil Composition>
The solid oil compositions according to the present invention in the following Production Examples and Comparative Production Examples were evaluated as follows.

(Melting Point)
Melting point measurement method No. 2 (hardness), a general test method for quasi-drug raw materials
94 parts by weight of the cleansing oil having the composition shown in Table 1 and 6 parts by weight of each solid oil composition of the Examples and Comparative Examples were heated and mixed at 90°C and dissolved uniformly. After that, 50 g of the composition was poured into a cylindrical polypropylene container having an inner diameter of 56 mm while still at 90°C, and allowed to cool overnight in a thermostatic bath at 25°C to form an oil gel. The hardness of the oil gel was measured by the method described below.
Using a Sun Rheometer CR-100 (manufactured by Sun Scientific Co., Ltd.), the specimen was penetrated to a depth of 10 mm at a penetration speed of 20 mm/min. with a 10 mmφ disk needle adapter at a maximum stress range of 2 kg, and the average stress from a penetration depth of 2 to 8 mm was recorded as the hardness (gf).

※１：商品名 ユニオックスＧＴ２０－ＩＳ（日油社製）
※２：商品名 エマレックスＧＷＩＳ－３０５（日本エマルジョン社製）
※ 表1において非イオン性界面活性剤の加重平均のＨＬＢ値は、９．４７５ Cleansing oil formula

*1: Product name: Uniox GT20-IS (manufactured by NOF Corp.)
*2: Product name: Emalex GWIS-305 (manufactured by Nippon Emulsion Co., Ltd.)
* The weighted average HLB value of the nonionic surfactants in Table 1 is 9.475.

(Production Examples 1 to 5, Comparative Production Examples 1 to 5)
A solid oil composition having the composition shown in Table 2 was produced according to the following production method. The melting point of the solid oil composition and the hardness of an oil gel obtained by dissolving the solid oil composition and a cleansing oil shown in Table 1 by heating and allowing to cool were evaluated by the above method. The evaluation results are shown in Table 2. Figure 1 shows a graph showing the relationship between the ratio (A-1)/[(A-1)+(A-2)] (mass%) of behenyl behenate (A-1) to Fischer-Tropsch wax (A-2), and the hardness and melting point for Production Examples 1 to 4 and Comparative Production Examples 1 to 3.

(Production method)
Solid oils having the compositions shown in Table 2 were melted at 95° C., mixed uniformly, and then allowed to cool to room temperature to obtain solid oil compositions.

※３：商品名 ＣＩＲＥＢＥＬＬＥ １０８（ＣＩＲＥＢＥＬＬＥ社製）
※４：商品名 ＰＥＲＦＯＲＭＡＬＥＮＥ５００（ニューフェーズテクノロジー社製）

*3: Product name: CIREBELLE 108 (manufactured by CIREBELLE)
*4: Product name: PERFORMALENE 500 (manufactured by New Phase Technology)

As is clear from FIG. 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 melting points of each of the components (A-1) and (A-2) alone, but the hardness of the oil gel from the solid oil composition, which is a mixture, was significantly higher than the value predicted from the hardness of each of the components alone. In particular, when the ratio (A-1)/[(A-1)+(A-2)] (mass%) is in the range of 20/95 to 95/100, it can be seen that high hardness can be obtained despite the low melting point. Comparative Production Example 4, in which the Fischer-Tropsch wax of Production Example 3 was replaced with a commonly used polyethylene wax, had a high melting point and the hardness of the oil gel was lower than that of Production Example 3. The combination of behenyl behenate and candelilla wax in Comparative Production Example 5 only produced an 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.

<Oil-based solid cleansing cosmetic>
The oily solid cleansing cosmetic compositions of the present invention in the following Examples and Comparative Examples were evaluated as follows.

(hardness)
The sample was heated and melted at 90° C., 50 g of the cosmetic was poured into a cylindrical polypropylene container having an inner diameter of 56 mm, and allowed to cool overnight in a thermostatic chamber at 25° C., and the hardness (gf) was measured by the following method.
Using a Sun Rheometer CR-100 (manufactured by Sun Scientific Co., Ltd.), the specimen was penetrated to a depth of 10 mm at a penetration speed of 20 mm/min using a 10 mmφ disk needle adapter at a maximum stress range of 2 kg, and the average stress from a penetration depth of 2 to 8 mm was recorded as the hardness.

(Shape retention)
The hardness was evaluated according to the following criteria.
A: Hardness 300 or more B: Hardness 200 or more and less than 300 C: Hardness 100 or more and less than 200 D: Hardness less than 100

(Easy to spread, removes makeup well, and is easy to wash off)
A panel of 10 female members with experience in makeup applied a commercially available powder foundation (Cezanne UV Foundation EX Plus, manufactured by Cezanne Cosmetics) to the skin, then cleansed the skin with the evaluation sample, and gave each item a score 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 as a cleansing cosmetic was judged according to the 4-point evaluation criteria shown in (2) below.

(1) Evaluation criteria 5 points: Good 4 points: Fairly good 3 points: Cannot say either way 2 points: Fairly bad 1 point: Bad

(2) 4-level judging criteria: A: Average score is 4 or more and 5 or less; B: Average score is 3 or more and less than 4; C: Average score is 2 or more and less than 3; D: Average score is less than 2.

Examples 1 to 3 and Comparative Examples 1 to 4
(Oily based solid cleansing cosmetic)
An oil-based solid cleansing cosmetic composition having the formulation shown in Table 3 was prepared according to the following manufacturing procedure. The obtained oil-based solid cleansing cosmetic composition was evaluated for hardness, shape retention, uniformity, ease of spreading, ease of makeup removal, and ease of rinsing using the above-mentioned methods. The evaluation results are shown in Table 3.

(Manufacturing procedure)
(1) Heat ingredients 1 to 14 shown in Table 3 to 82°C and mix uniformly.
(2) The mixture prepared in (1) above is filled into a jar container at 70° C. in a molten state, and then allowed to cool to give an oil-based solid cleansing cosmetic.

From the results in Table 3, the oil-based solid cleansing cosmetics of Examples 1 to 3 had sufficient shape retention for easy portability, and formed a uniform oil gel even at the relatively mild manufacturing temperature of 82°C. They were also excellent in terms of ease of spreading, makeup removal, and washability. In contrast, the cosmetics of Comparative Example 1, which contains only Fischer-Tropsch wax without behenyl behenate as the solid oil component, and Comparative Example 2, which contains polyethylene wax, were unable to completely melt at the same manufacturing temperature and were unable to form a uniform oil gel, resulting in low hardness and insufficient shape retention. The cosmetics of Comparative Example 3, which contain candelilla wax and behenyl behenate as solid oil components, had insufficient shape retention. The cosmetics of Comparative Example 4, which does not contain a nonionic surfactant, were inferior in makeup removal and washability.

The present invention provides an oil-based solid cleansing cosmetic that has excellent cleansing performance, is easy to manufacture, and has excellent biodegradability.

Claims (4)

An oil-based solid cleansing cosmetic comprising (A) 3 to 20 mass% of a solid oil having a melting point of 50 to 120°C, (B) 60 to 92 mass% of a liquid oil, and (C) 5 to 30 mass% of a nonionic surfactant having an HLB value of 5 to 13 (proportion relative to the total amount of the cosmetic),
The solid oil (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 ,
the sum of the contents of the components (A-1) and (A-2) in the solid oil (A) is 50% by mass or more based on the total amount of the solid oil (A);
The liquid oil (B) is at least one selected from ethylhexyl palmitate, caprylic/capric triglyceride, triethylhexanoin, dicaprylyl carbonate, diisostearyl malate, diglyceryl triisostearate, decaglyceryl decaisostearate, oligomer ester of dimer acid and dimer diol, pentaerythritol tetraisostearate, diglyceryl tetraisostearate, cetyl ethylhexanoate, isopropyl myristate, isopropyl palmitate, octyldodecyl myristate, neopentyl glycol dioctanoate, cholesterol fatty acid ester, and jojoba oil;
The oil-based solid cleansing cosmetic preparation, wherein the nonionic surfactant (C) is at least one selected from polyoxyethylene fatty acid esters, polyoxyethylene fatty acid glyceryls, fatty acid polyoxyethylene hydrogenated castor oils, and fatty acid polyoxyethylene alkyl ethers, and the fatty acid is a fatty acid having 10 to 22 carbon atoms . 2. 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 amount of the solid oil (A). 3. The oil-based solid cleansing cosmetic according to claim 1, comprising 1 to 15 % by mass of component (A-1) and 0.5 to 15 % by mass of component (A- 2 ) based on the total mass of the cosmetic. A method for producing an oil-based 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 at least one selected from ethylhexyl palmitate, tri(caprylic/capric acid)glyceryl, triethylhexanoin, dicaprylyl carbonate, diisostearyl malate, diglyceryl triisostearate, decaglyceryl decaisostearate, oligomer ester of dimer acid and dimer diol, pentaerythritol tetraisostearate, diglyceryl tetraisostearate, cetyl ethylhexanoate, isopropyl myristate, isopropyl palmitate, octyldodecyl myristate, neopentyl glycol dioctanoate, cholesterol fatty acid ester, and jojoba oil .

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