Oily cleansing cosmetic

Abstract

The present invention is an oily cleansing cosmetic containing (A) 1-40% by mass of a glycerin fatty acid ester and (B) 60-99% by mass of an oil component, the component (A) being an ester of a C14-22 fatty acid and diglycerin, the content of a diglycerol monoester in the ester being 80% by mass or more, and the HLB value of the ester being 6 or more and less than 8. The content of diglycerol monoester in the ester is preferably 85 mass% or more, and the content of diglycerol is preferably 5 mass% or less.

Description

Technical Field

[0001] The present invention relates to a novel oil-based cleansing cosmetic based on a liquid oil. More specifically, it relates to an oil-based cleansing cosmetic containing a specific diglycerol fatty acid ester and a liquid oil. Background Art

[0002] In recent years, in makeup cosmetics such as lipsticks, foundations, eyeshadows, and mascaras, products with excellent water resistance and oil resistance have been developed, and the makeup retention has been significantly improved. Therefore, when removing the makeup film using makeup cosmetics, it is preferable to use an oil-based cleansing cosmetic that has good compatibility with the makeup (the makeup film on the skin) and excellent performance in removing dirt such as cutin and sebum (dirt removability). As specific examples of such oil-based cleansing cosmetics, for example, cleansing oil and an oil-based solid cleansing cosmetic called cleansing paste obtained by solidifying cleansing oil with wax are known.

[0003] An oil-based cleansing cosmetic is usually composed of an oil agent responsible for the cleansing property of makeup and a nonionic surfactant for emulsifying the oil agent and rinsing it. The nonionic surfactant used is required to meet the following requirements: stably dissolve in the oil agent, have high emulsifying ability to effectively rinse the oil agent with water, and have no irritation to the eyes or other irritation to the human body. For these reasons, polyoxyethylene-based surfactants that can be relatively easily adjusted to the optimal hydrophilic-lipophilic balance (HLB) value are often used as nonionic surfactants. However, since polyoxyethylene-based surfactants are petroleum-based surfactants, there is some concern from the perspective of safety / peace of mind, and the development of oil-based cleansing cosmetics using polyglycerol fatty acid esters of natural origin as nonionic surfactants with higher safety is being promoted.

[0004] As a specific example of a cleansing oil that does not contain a polyoxyethylene-based surfactant, for example, Patent Document 1 discloses a cleansing oil containing polyglycerol long-chain fatty acid ester as a nonionic surfactant, a medium-chain fatty acid having 6 to 10 carbon atoms, a polyglycerol ester having an average degree of polymerization of 3 to 10, and an oil agent (see Claim 1 and Table 1 in Paragraph 0054). However, the polyglycerol medium-chain fatty acid ester generally has problems such as insufficient solubility in oil, difficulty in obtaining an oily cleansing cosmetic with uniform properties, and on top of that, the uniformity of the preparation is easily damaged over time.

[0005] In addition, Patent Document 2 discloses a gel-like composition containing a polyglycerol fatty acid ester having an HLB value of 8 or more and less than 10 and a monoester content of 70% by mass or more. As specific examples of the polyglycerol fatty acid ester, diglycerol monolaurate and triglycerol monooleate are described (see Table 1 in paragraph 0025). Further, it is described that the gel-like composition can be applied to cleansing cosmetics (paragraph 0018). However, since the HLB value of this polyglycerol fatty acid ester is also 8 or more, similar to the case of the cleansing oil described in Patent Document 1, there is a problem that the solubility in oil is low and it is difficult to prepare a stable and homogeneous preparation.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2005-162691

[0009] Patent Document 2: Japanese Unexamined Patent Application Publication No. 2007-314428 Summary of the Invention

[0010] Problems to be Solved by the Invention

[0011] The present invention has been completed under such a background art, and an object thereof is to provide an oil-based cleansing cosmetic having excellent cleansing effects, low irritation, excellent stability of the system, and excellent rinsability.

[0012] The inventors of the present invention conducted intensive studies to solve the above problems, and as a result, found that by using a specific diglycerol fatty acid ester as a nonionic surfactant for emulsifying an oil agent, an oil-based cleansing cosmetic that can solve the above problems can be obtained, thereby completing the present invention.

[0013] Therefore, according to the present invention, there is provided an oil-based cleansing cosmetic containing (A) 1 to 40% by mass of a glycerol fatty acid ester and (B) 60 to 99% by mass of an oil component, wherein the component (A) is an ester of a fatty acid having 14 to 22 carbon atoms and diglycerol, the content of diglycerol monoesters in the ester is 80% by mass or more, and the HLB value of the ester is 6 or more and less than 8.

[0014] Effects of the Invention

[0015] The oil-based cleansing cosmetic of the present invention has excellent cleansing effects, low irritation, excellent stability of the system, and excellent rinsability. Detailed Description of the Invention

[0016] (A) Glycerol Fatty Acid Ester

[0017] Regarding the glycerol fatty acid ester of component (A) used in the present invention, it is formulated for the purpose of easily rinsing the oil component of component (B) in which makeup dirt is dissolved or dispersed with water. Therefore, not only is a high solubility in the oil component required, but also a property of emulsifying the oil component when in contact with water to form an oil-in-water (O / W) type emulsion and facilitating its dispersion in water is required. The glycerol fatty acid ester of component (A) is an ester of diglycerol and a specific fatty acid, and its HLB value is 6 or more and less than 8, preferably 7 or more and less than 8. If the HLB value of component (A) is 8 or more, the solubility in the oil component is insufficient, the oily cleansing cosmetic cannot maintain a uniform property, and separation over time easily occurs, causing problems in storage stability. On the other hand, if the HLB value of component (A) is less than 6, it is difficult to form an oil-in-water type emulsion when rinsing the oily cleansing cosmetic with water. As a result, it becomes difficult to rinse, and in addition, the refreshing feeling after rinsing is poor.

[0018] In this specification, the HLB value of component (A) is calculated according to the Atlas method and the following formula.

[0019] HLB = 20 - (1 - SV / NV)

[0020] SV: Saponification value of polyol fatty acid ester.

[0021] NV: Neutralization value of raw material fatty acid.

[0022] Regarding the glycerol fatty acid ester of component (A) used in the present invention, the content of the highly hydrophilic monoesters is 80% by mass or more. Therefore, since the contents of diesters and triesters with low hydrophilicity and poor emulsifying power for water are small, an oily cleansing cosmetic with excellent rinsing property can be produced. The larger the content of the monoesters, the more preferable, preferably 85% by mass or more, more preferably 88% by mass or more, and particularly preferably 90% by mass or more. The larger the content of the monoesters, the smaller the contents of diesters and triesters with low hydrophilicity and poor emulsifying power for water, and thus the rinsing property of the oily cleansing cosmetic becomes good.

[0023] Regarding the glycerol fatty acid ester of component (A) used in the present invention, components other than the monoesters may be included in a range of less than 20% by mass. However, when the component other than the monoesters is diglycerol not bonded to a fatty acid, its content is preferably 5% by mass or less, more preferably 3% by mass or less. When the content of diglycerol is excessive, component (A) is difficult to dissolve in the oil component, and component (A) easily separates from the oil component as component (B).

[0024] The fatty acid that constitutes component (A) used in the present invention has 14 to 22 carbon atoms, preferably 16 to 20, and more preferably 18. When the number of carbon atoms of the fatty acid is too small, it is likely to cause irritation to the eyes and reduce safety. When the number of carbon atoms of the fatty acid is too large, its solubility in the oil component decreases.

[0025] The fatty acid may be linear or branched. In addition, it may be a saturated fatty acid or an unsaturated fatty acid. Furthermore, it may have a hydroxyl group.

[0026] Examples of the fatty acid include: linear saturated fatty acids such as myristic acid, palmitic acid, stearic acid, and behenic acid; unsaturated fatty acids such as palmitoleic acid, oleic acid, and linoleic acid; branched saturated fatty acids such as hexyl decanoic acid and isostearic acid; fatty acids with a hydroxyl group such as 12-hydroxy stearic acid. Among them, from the perspective of solubility in the oil component, unsaturated fatty acids and branched saturated fatty acids are preferred. Specifically, oleic acid and isostearic acid are particularly preferably used.

[0027] In the present invention, isostearic acid refers to a mixture of one or more of the branched stearic acids. For example, 5,7,7-trimethyl-2-(1,3,3-trimethylbutyl)-octanoic acid can be prepared by the hydroformylation reaction (Oxo Reaction) of isobutene dimer to form a branched aldehyde with 9 carbon atoms, and then by aldol condensation of the aldehyde to form a branched unsaturated aldehyde with 18 carbon atoms, and then by hydrogenation reaction and oxidation reaction (hereinafter referred to as "aldol condensation type"). Aldol condensation type isostearic acid is commercially available from Nissan Chemical Industries, Ltd. In addition, 2-heptylundecanoic acid can be prepared by dimerizing nonanol through the Guerbet reaction (also known as the Guérbet reaction) and then oxidizing it. 2-heptylundecanoic acid is commercially available from Mitsubishi Chemical Corporation, and similar compounds with slightly different branching positions are commercially available from Nissan Chemical Industries, Ltd. Furthermore, the type of starting alcohol that is branched at two positions rather than a linear alcohol is also commercially available from Nissan Chemical Industries, Ltd. (hereinafter all simply referred to as "Guerbet reaction type").

[0028] Furthermore, isostearic acid known as Emery type can be used. Emery type isostearic acid refers to isostearic acid with 18 carbon atoms, having a methyl group in the side chain and an uncertain structure, which is obtained by hydrogenating unsaturated fatty acids by-produced when synthesizing dimer acid from oleic acid [for example, refer to J.Amer.Oil Chem.Soc.51, 522 (1974)]. As specific examples thereof, products commercially available from Emery Company of the United States and the like, and isostearic acid EX manufactured by Advanced Alcohol Industries Co., Ltd. can be cited. As the starting material of dimer acid, which is the starting material of Emery type isostearic acid, in addition to oleic acid, linoleic acid, linolenic acid, etc. may sometimes be included. In the present invention, from the viewpoint of the reactivity of the esterification reaction between diglycerol and isostearic acid, it is particularly preferred to use Emery type isostearic acid.

[0029] In the present invention, diglycerol as the component (A) is a dimer of glycerol. Generally, diglycerol is produced by the dehydration condensation reaction of glycerol. In this case, the reaction solution after the reaction contains unreacted glycerol, diglycerol as the target product, and polyglycerol with three or more polymerizations. However, the content of diglycerol is increased by refining the reaction solution by distillation or the like, thereby producing diglycerol as a product. Therefore, the term "diglycerol" in the present invention does not refer only to pure diglycerol, and as long as the purity is 85% by mass or more, preferably 90% by mass or more, a small amount of glycerol and triglycerol are allowed to be included. If the purity of diglycerol is less than 85% by mass, the water washability during cleaning may sometimes deteriorate.

[0030] Regarding the glycerol fatty acid ester of the component (A) used in the present invention, the diglycerol and the fatty acid are subjected to an esterification reaction by a known method, and by removing by-products such as unreacted substances, diesters, and triesters from the obtained product, the content of the monoester is refined to 80% by mass or more. An overview of a specific manufacturing method is described below.

[0031] In a usual reaction vessel equipped with a stirrer, a jacket for heating, baffles, etc., diglycerol and a fatty acid are charged in a molar ratio of 1:0.2 to 2, and an esterification reaction is carried out in an inert gas atmosphere such as nitrogen or carbon dioxide using an alkali catalyst (such as caustic soda, etc.) by a conventional method. After the reaction is completed, the catalyst remaining in the reaction mixture is neutralized to obtain a reaction solution. The heating temperature of the esterification reaction is 200 to 260 °C, preferably 210 to 240 °C. In addition, the reaction can be carried out under reduced pressure or normal pressure, and the reaction time is 0.5 to 10 hours, preferably 1 to 5 hours. The end point of the reaction can be determined by measuring the acid value of the reaction solution, and it is preferably determined that the acid value is 3 or less. The obtained reaction solution is a mixture containing unreacted fatty acid, unreacted diglycerol, monoglyceride of diglycerol fatty acid, diglyceride of diglycerol fatty acid, triglyceride of diglycerol fatty acid, etc. The reaction solution is distilled under reduced pressure to distill off unreacted diglycerol, and then, if necessary, molecular distillation is carried out using, for example, a falling film molecular distillation apparatus or a centrifugal molecular distillation apparatus, or purification is carried out using a known method such as column chromatography or liquid-liquid extraction, so that the content of the monoglyceride body is 80% by mass or more.

[0032] In the oily cleansing cosmetic of the present invention, the content of the glycerol fatty acid ester of component (A) is 1 to 40% by mass, preferably 2 to 35% by mass, more preferably 5 to 30% by mass based on the whole cosmetic. When the content of component (A) is too small, the rinsing property with water is poor, the oil component containing makeup dirt is likely to remain on the skin, and there will be a sticky feeling after rinsing. When the content of component (A) is too large, skin irritation and skin degreasing may be caused by the surfactant.

[0033] (B) Oil component

[0034] Regarding the oil component of component (B) used in the present invention, there is no particular limitation as long as it is usually used in cosmetics, and liquid oils and solid oils can be used. In addition, animal oils, vegetable oils, and synthetic oils are all acceptable. In this specification, a liquid oil refers to an oil component having a melting point of less than 50 °C and being in a liquid to semi-solid state at normal temperature, and also includes a volatile oil component having a boiling point of less than 260 °C. A solid oil refers to an oil component having a melting point of 50 °C or more and being in a solid state at normal temperature.

[0035] As specific examples of the liquid oil, the following can be cited: esters such as ethylhexyl palmitate, glyceryl tri (caprylate / caprate), glyceryl triethylhexanoate, dicaprylyl carbonate, diisostearyl malate, diglyceryl triisostearate, decaglyceryl decaisostearate, oligomer esters of dimer acid and diol, pentaerythritol tetraiso-stearate, diglyceryl tetraiso-stearate, cetyl hexylhexanoate, isopropyl myristate, isopropyl palmitate, octyldodecyl myristate, neopentyl glycol dicaprylate, cholesterol fatty acid ester, jojoba oil; hydrocarbons such as volatile isoparaffin, polybutene, polyisobutene, heavy liquid isoparaffin, liquid paraffin, α-olefin oligomer, squalane, petrolatum; oils and fats such as olive oil, castor oil, mink oil, macadamia oil; fatty acids such as isostearic acid, oleic acid; higher alcohols such as oleyl alcohol, isostearyl alcohol; silicone oils such as low-polymerization-degree dimethylpolysiloxane, cyclic silicone, high-polymerization-degree dimethylpolysiloxane, methylphenylpolysiloxane, methyltrimethylpolysiloxane, octanoyltrimethylpolysiloxane, crosslinked organopolysiloxane, fluorine-modified polysiloxane; fluorine-based oil agents such as perfluoropolyether; lanolin derivatives such as lanolin, lanolin acetate, isopropyl lanolate, lanolin alcohol; etc.

[0036] Among the oil components, from the viewpoints of removability of makeup dirt, ease of rinsing, and solubility of component (A), the use of esters is preferred. Among the esters, the use of ethylhexyl palmitate, glyceryl tri (caprylate / caprate), glyceryl triethylhexanoate, and dicaprylyl carbonate is particularly preferred. The ratio of the ester oil in component (B) is not particularly limited, but the ratio is preferably 50% by mass or more.

[0037] In the present invention, the oil component of component (B) may contain solid oil. By containing solid oil in component (B), the dosage form of the oily cleansing cosmetic can be made into an oily solid cleansing cosmetic. The oily solid cleansing cosmetic has the advantages that it does not drip during use and is also convenient for massage.

[0038] In the present invention, the solid oil refers to an oil that is solid at normal temperature (25 °C), and its melting point is preferably 50 to 120 °C, more preferably 55 °C to 105 °C, and particularly preferably 60 to 100 °C. The melting point of the solid oil component can be measured by the second method of melting point measurement, which is a general test method for the specifications of raw materials for quasi-drugs. In the case where the melting point is too low, the liquid oil cannot be uniformly solidified. In addition, during the transportation and carrying of the oily solid cleansing cosmetic, it is likely to be liquefied due to vibration and impact, or the shape retention property is poor and it cannot maintain the solid shape. On the contrary, in the case where the melting point is too high, the composition becomes hard and it is difficult to pick up with fingers when used as a cleansing cosmetic, and when it is melted, it requires an operation at a high temperature, so it is likely to cause oxidative deterioration of other components.

[0039] As the solid oil, specifically, for example, the following can be cited: hydrocarbon waxes such as paraffin wax, polyethylene wax, ethylene-propylene copolymer, microcrystalline wax, Cera Sinensis, Ozokerite, Fischer-Tropsch wax; wood wax, carnauba wax, candelilla wax, rice bran wax, beeswax, hydrogenated jojoba oil, hardened oil, behenyl behenate, higher alcohols, silicone wax, etc.

[0040] The solid oil can be used by selecting a single compound. In addition, two or more compounds can also be appropriately combined and used. When the oily cleansing cosmetic of the present invention is made into an oily solid cleansing cosmetic (sometimes called a cleansing cream), the content of the solid oil is preferably 1 to 30% by mass, more preferably 2 to 20% by mass, based on the total amount of the cosmetic.

[0041] When the dosage form of the oily cleansing cosmetic of the present invention is made into a cleansing oil, it has the advantage of being easily applied to a cotton pad or the like. When the dosage form is made into a cleansing oil, considering the fluidity and transparent appearance, the content of the solid oil is preferably 3% by mass or less, more preferably 1% by mass or less, based on the total amount of the cosmetic.

[0042] In the total amount of the oily cleansing cosmetic, the content of the (B) oil component is 60 to 99% by mass, preferably 65 to 98% by mass, more preferably 70 to 95% by mass. By setting the content of the oil component within this range, good detergency (cosmetic removal performance) can be achieved.

[0043] The oily cleansing cosmetic of the present invention can contain components for ordinary cosmetics within the range that does not impair the effects of the present invention, such as water, nonionic surfactant other than component (A), powder, oily gelling agent, polyhydric alcohols, lower alcohols, pigments, ultraviolet protectants, moisturizers, fragrances, antioxidants, preservatives, antifoaming agents, beauty components, various extracts, and other additives.

[0044] (Powder)

[0045] When a powder is incorporated into the oil-based cleansing cosmetic of the present invention, the powder contributes to the adsorption of makeup dirt, provides appropriate friction during massage, and also helps to improve the refreshing feeling after makeup removal and rinsing as well as the massage effect. The powder is not particularly limited as long as it can be used in cosmetics, and can be used regardless of its particle size, material (organic, inorganic, etc.), shape (spherical, needle-like, plate-like, etc.), particle structure (porous, non-porous, etc.). Among them, powders with a porous structure or a large specific surface area are preferably used because of their excellent performance in adsorbing makeup dirt. From the viewpoints of the feel during massage and dispersion stability, the volume average particle diameter of the powder measured by a laser diffraction / scattering particle size distribution measuring device is preferably 0.01 to 200 μm.

[0046] Examples of the powder include: clay minerals such as talc, muscovite, synthetic muscovite, phlogopite, synthetic fluorophlogopite, sericite, zeolite, kaolin, bentonite, soapstone, lithium montmorillonite, natural clay, sea mud, activated clay; inorganic oxides or inorganic salts such as silicic acid, anhydrous silicic acid (silicon dioxide), magnesium silicate, magnesium aluminum silicate, calcium silicate, barium sulfate, magnesium carbonate, boron nitride, bismuth oxychloride, aluminum oxide, zirconium oxide, hydroxyapatite; organic powders such as silicone powder, silicone elastomer powder, polyurethane powder, cellulose powder, nylon powder, silk powder, polymethyl methacrylate (PMMA) powder, starch, polyethylene powder, lauroyl lysine, metal soap, plant powders (apricot kernel particles, walnut kernel particles, glucomannan powder, etc.); carbon powders such as activated carbon, medicinal carbon, bamboo carbon; and their composites and granulates.

[0047] (Oil-based gelling agent)

[0048] When the dosage form of the oil-based cleansing cosmetic of the present invention is made into an oil-based gel cleansing cosmetic, an oil-based gelling agent is preferably used. Examples of the oil-based gelling agent preferably used include: dextrin fatty acid ester, glycerol fatty acid ester, an esterification product of glycerol or a condensate of glycerol with an average degree of polymerization of 2 or more, a straight-chain saturated fatty acid having 18 to 28 carbon atoms, and an aliphatic saturated dicarboxylic acid having 20 to 28 carbon atoms, hydroxy stearic acid, amide or ester derivatives of long-chain acyl amino acids such as dibutyl lauroyl glutamate, and organically modified clay minerals. Among them, glyceryl behenate / eicosanedioate, which is an esterification product of glycerol, a straight-chain saturated fatty acid, and an aliphatic saturated dicarboxylic acid, is preferably used. When an oil-based gelling agent is contained, its content can be set to 0.1 to 20% by mass based on the whole cosmetic.

[0049] The oily cleansing cosmetic of the present invention can be made into a cleansing oil having a viscosity of 1 to 5000 mPa·s at normal temperature (25°C). In addition, it can also be made into an oily solid cleansing cosmetic that does not show fluidity at normal temperature (25°C). Specific examples of the shape of the solid cosmetic include: stick shape, rod shape, plate shape, shape formed by pouring into a container, etc. Furthermore, it can also be made into an oily gel cleansing cosmetic.

[0050] These various cleansing cosmetics can be prepared by conventional methods. For example, in the case of an oily solid cleansing cosmetic, all the raw materials can be heated above the melting point, uniformly mixed, and then directly poured into a container, mold, etc. in a molten state, and cooled or allowed to cool to make an oily solid cleansing cosmetic. In the case of an oily gel cleansing cosmetic, all the raw materials containing an oily gelling agent can be uniformly mixed with or without heating, then cooled to room temperature, and then filled into a container for preparation.

[0051] When using the oily cleansing cosmetic of the present invention, the cosmetic can be melted in makeup and then rinsed with water or warm water to remove the makeup. The rinsability and the refreshing feeling after rinsing of the oily cleansing cosmetic of the present invention are excellent, so further face washing operations with face wash pigments, etc. can be omitted after use.

[0052] [Examples]

[0053] Hereinafter, the present invention will be further specifically described by giving examples and comparative examples, but the present invention is not limited by these examples. It should be noted that "parts" and "%" in the following description are based on mass, and the compounding amounts in the composition are mass % relative to the total amount unless otherwise specified.

[0054] (Diglycerol fatty acid ester)

[0055] In the following examples and comparative examples, the diglycerol fatty acid esters shown in Table 1 were used. Samples I-1, O-1, and S-1 were manufactured by the methods shown in the following Production Examples 1 to 3. Samples I-2 to I-6 were commercially available as cosmetic raw materials under the name of isostearic acid diglycerol ester in Japan, and were all provided by different raw material manufacturers. For each diglycerol fatty acid ester, the HLB value, monoglyceride content, diglyceride content, triglyceride and tetraglyceride content, and the content of diglycerol not bonded to fatty acid are shown in Table 1. The HLB value was calculated by the above-mentioned Atlas method, and the composition analysis was carried out according to the following method.

[0056] (Composition analysis)

[0057] The contents of monoglyceride, diglyceride, triglyceride, and tetraglyceride were measured by GPC (gel permeation chromatography). The measurement conditions are as follows.

[0058] <GPC analysis conditions>

[0059] Apparatus: Shimadzu high performance liquid chromatograph.

[0060] Pump (Model: LC-20AD; manufactured by Shimadzu Corporation).

[0061] Column oven (Model: CTO-20A; manufactured by Shimadzu Corporation).

[0062] Data processing device (Model: LCsolution; manufactured by Shimadzu Corporation).

[0063] Column: Two GPC columns (Model: SHODEX KF-801; manufactured by Showa Denko KK) connected.

[0064] Mobile phase: Tetrahydrofuran (THF).

[0065] Flow rate: 1.0 mL / minute.

[0066] Detector: RI detector (Model: RID-10A; manufactured by Shimadzu Corporation).

[0067] Column temperature: 40 °C.

[0068] Injection volume: 15 μL (dissolved in THF).

[0069] (Manufacture of diglycerol fatty acid ester)

[0070] <Production Example 1>

[0071] In a 3 L four-necked flask equipped with a stirrer, thermometer, gas inlet tube, and water separator, 775 parts of diglycerol (trade name: Diglycerol S; manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.), 1625 parts of isostearic acid (trade name: PALMERA IS30; manufactured by KLKOLEO Co., Ltd.), and 12 parts of caustic soda (trade name: Sodium hydroxide; manufactured by KISHIDA CHEMICAL Co., Ltd.) were added. While introducing nitrogen, the temperature was raised to 230 °C and the reaction was carried out for 4 hours to obtain 2200 parts of a reaction solution with an acid value of 0.6. 2000 parts were taken from the obtained reaction solution and subjected to vacuum distillation (210 °C, 5 Pa) to remove unreacted diglycerol, and then further subjected to vacuum distillation (230 °C, 1 Pa) to obtain 314 parts of isostearic acid diglycerol ester (Sample I-1) as an esterification product. The content of the monoester form in the obtained esterification product was 91.8%, and the content of unreacted diglycerol was 2.4%.

[0072] <Production Example 2>

[0073] Isostearic acid was replaced with oleic acid (trade name: LUNAC O-V; manufactured by Kao Corporation). Otherwise, 298 parts of diglycerol oleate (specimen O-1) as an esterification product was obtained in the same manner as in Production Example 1. The content of the monoester in the obtained esterification product was 88.2%, and the content of unreacted diglycerol was 4.8%.

[0074] <Production Example 3>

[0075] Isostearic acid was replaced with stearic acid (trade name: LUNAC S-65V; manufactured by Kao Corporation). Otherwise, 298 parts of diglycerol stearate (specimen S-1) as an esterification product was obtained in the same manner as in Production Example 1. The content of the monoester in the obtained esterification product was 86.8%, and the content of unreacted diglycerol was 5.1%.

[0076] The types and properties of the diglycerol fatty acid esters used in the examples and comparative examples are shown in Table 1.

[0077] [Table 1]

[0078]

[0079] As shown in the analysis results of Table 1, the monoester content of the diglycerol fatty acid esters of specimens I-1, O-1, and S-1 (Production Examples 1 to 3) exceeded 80%, but the monoester content of all five commercially available products was less than 50% by mass. It should be noted that for the diglycerol fatty acid esters used in cosmetics, etc., for example, in the case of diglycerol isostearate (cosmetic label name: polyglyceryl-2 isostearate), generally, in the products sold under this name, in addition to containing the monoester formed by the bonding of one isostearic acid and diglycerol, which conforms to the product name, there are also mostly di-esters, tri-esters, tetra-esters formed by the bonding of 2 to 4 isostearic acids and diglycerol, and diglycerol not bonded to fatty acids in amounts exceeding the impurity level.

[0080] <Cleansing Oil>

[0081] The evaluation method of the cleansing oil of the present invention in the following examples and comparative examples is as described below.

[0082] (Stability)

[0083] A specimen was prepared and kept at room temperature (25°C). Then, the state of the system was visually observed immediately after preparation, after storage at room temperature for 1 day, and after storage at 5°C for 1 day, and the determination was made according to the following determination criteria.

[0084] A: Transparent and dissolved immediately after preparation and after 1 day.

[0085] B: Transparent immediately after preparation, but after storage at 5°C for 1 day, an opaque part separated to the lower layer.

[0086] C: Transparent when freshly prepared, but after being stored at room temperature for 1 day, the opaque part separates to the lower layer.

[0087] D: Opaque when freshly prepared and separates afterwards.

[0088] (Degree of good makeup removal, ease of rinsing, feeling of freshness after rinsing)

[0089] After 10 female panel members with makeup experience applied a commercially available powder foundation (Powder foundation) (manufactured by Chacott Cosmetics Co., Ltd., Chacott UV Foundation EX plus) on the skin, they used the test samples for evaluation to clean. For each item, they scored on a scale of 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 judged according to the four-grade judgment criteria shown in (2) below.

[0090] (1) Evaluation criteria

[0091] 5 points: Good.

[0092] 4 points: Relatively good.

[0093] 3 points: Neither good nor bad.

[0094] 2 points: Poor.

[0095] 1 point: Bad.

[0096] (2) Four-grade judgment criteria

[0097] A: The average score is above 4 points.

[0098] B: The average score is above 3 points and less than 4 points.

[0099] C: The average score is above 2 points and less than 3 points.

[0100] D: The average score is less than 2 points.

[0101] (Eye irritation test)

[0102] 10 female panel members mentioned above soaked 2 g of the test sample in a cotton pad, rubbed it around the eyes for 1 minute, and then washed it with warm water. Regarding whether there was irritation to the eyes, they scored on a scale of 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 judged according to the four-grade judgment criteria shown in (2) below.

[0103] (1) Evaluation criteria

[0104] 5 points: None at all.

[0105] 4 points: Almost none.

[0106] 3 points: A little.

[0107] 2 points: Quite a lot.

[0108] 1 point: There is irritation and it is aborted halfway.

[0109] (2) Four-level judgment criteria

[0110] A: The average score is above 4 points.

[0111] B: The average score is above 3 points and less than 4 points.

[0112] C: The average score is above 2 points and less than 3 points.

[0113] D: The average score is less than 2 points.

[0114] (Dispersibility in water)

[0115] Perform the following operations (1) and (2), and judge the dispersibility in water according to the following criterion (3).

[0116] (1) Put 10 g of the sample and 10 g of purified water into a 50 mL beaker, stir with a magnetic stirrer for 2 minutes in an atmosphere of 25 °C, and measure the resistance with a resistance tester while stirring. If the resistance value shows infinity, it is judged that the emulsion type is W / O (water-in-oil), and if there is current passing through, it is judged that the emulsion type is O / W (oil-in-water).

[0117] (2) For the sample judged to be of the O / W type, put the mixture in (1) into a 30 mL transparent glass container (screw tube No. 6 manufactured by Maruemu Co., Ltd.), cover the lid, shake it vigorously up and down 20 times, and then let it stand in a 25 °C room. After 24 hours, measure whether there is a separated transparent water layer at the bottom layer and its height.

[0118] (3) Four-level judgment criteria

[0119] In the case where the emulsion type is W / O, the dispersibility in water is the worst. Among the O / W types, the finer the emulsion particles, the better the dispersibility in water. Samples with good dispersibility in water are easily emulsified when in contact with water, and as a result, they are also easily washed with water.

[0120] A: No water layer separation is seen, and it is uniformly turbid white.

[0121] B: It is separated into a transparent water layer at the bottom layer and a uniformly turbid white layer at the upper layer, and the height of the bottom layer is less than 3 mm.

[0122] C: It is separated into a transparent water layer at the bottom layer and a uniformly turbid white layer at the upper layer, and the height of the bottom layer is 3 mm or more.

[0123] D: W / O type emulsification.

[0124] Examples 1 - 2 and Comparative Examples 1 - 5

[0125] Prepare a cleansing oil with the formulation shown in Table 2 according to the following manufacturing sequence. For the obtained cleansing oil, the stability, the degree of good makeup removal, ease of rinsing, refreshing feeling after rinsing, eye irritation, and dispersibility in water were evaluated by the above methods. The evaluation results are shown in Table 2.

[0126] (Manufacturing sequence)

[0127] Uniformly mix the components 1 - 9 shown in Table 2 at room temperature (25°C).

[0128] [Table 2]

[0129]

[0130] According to the results in Table 2, the cleansing oils of Examples 1 - 2 are excellent in terms of stability, the degree of good makeup removal, ease of rinsing, refreshing feeling after rinsing, eye irritation, and emulsifying power. In contrast, the cleansing oils of Comparative Examples 1 - 5 using diglycerol fatty acid esters with a low monoglyceride content are poor in terms of ease of rinsing, refreshing feeling after rinsing, and dispersibility in water.

[0131] Examples 3, 4 and Comparative Examples 6 - 8

[0132] Prepare a cleansing oil with the formulation shown in Table 3 according to the same manufacturing sequence as above. For the obtained cleansing oil, the stability, the degree of good makeup removal, ease of rinsing, refreshing feeling after rinsing, eye irritation, and dispersibility in water were evaluated by the above methods. The evaluation results are shown in Table 3. The diglycerol fatty acid esters used were a mixture of isostearic acid diglycerides of Specimen I - 1 and Specimen I - 2 at various ratios. For comparison, Example 1 and Comparative Example 1 are also described in Table 3.

[0133] [Table 3]

[0134]

[0135] From the results in Table 3, it can be seen that the cleansing oils of Examples 3 and 4 show good results in all items. In contrast, the cleansing oils of Comparative Examples 6 - 8 and Comparative Example 1 with a monoglyceride content of less than 80% by mass in the diglycerol fatty acid ester are poor in terms of ease of rinsing, refreshing feeling after rinsing, and dispersibility in water.

[0136] Comparative Examples 9 - 15

[0137] A cleansing oil having the formulation shown in Table 4 was prepared in the same manufacturing order as described above. For the obtained cleansing oil, the stability, the degree of good makeup removal, the ease of rinsing, the refreshing feeling after rinsing, and the eye irritation were evaluated by the above-described method. The evaluation results are shown in Table 4. It should be noted that the HLB values of the commercially available polyglycerol fatty acid esters described in Table 4 are the HLB values described in the catalog of the raw material manufacturing company.

[0138] [Table 4]

[0139]

[0140] ※1 Trade name SunsoftQ-192Y-C (manufactured by Sun Chemical Corporation)

[0141] ※2 Trade name SY-Glyster ML-310

[0142] ※3 Trade name SunsoftQ-102H-C (manufactured by Sun Chemical Corporation)

[0143] ※4 Trade name SunsoftQ-10D-C (manufactured by Sun Chemical Corporation)

[0144] ※5 Trade name S Face IS-401-P (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.)

[0145] ※6 Trade name EMALEX DISG-3 (manufactured by Nippon Emulsion Co., Ltd.)

[0146] ※7 Trade name Decaglyn 5-ISV (manufactured by Nikko Chemicals Co., Ltd.)

[0147] From the results in Table 4, it can be seen that when various commercially available polyglycerol fatty acid esters are used in place of the diglycerol fatty acid ester used in the present invention, good results are not shown in all items. When the number of carbon atoms of the fatty acid constituting the polyglycerol fatty acid ester is less than 14 (Comparative Examples 10 to 12), there is a problem with eye irritation. When a polyglycerol fatty acid ester having a high HLB value is used (Comparative Examples 9 to 11), there is a problem with stability. In addition, when a polyglycerol ester having an HLB value lower than 6 is used (Comparative Examples 14 to 15), there are problems with the ease of rinsing and the refreshing feeling after rinsing. Furthermore, for commercially available polyglycerol fatty acid esters, even if the system stability is good, it cannot be said that the ease of rinsing and the refreshing feeling after rinsing are sufficient (Comparative Examples 12 to 13).

[0148] <Oily solid cleansing cosmetic, oily gel cleansing cosmetic>

[0149] In the following Examples and Comparative Examples, the evaluation methods for the oil-based solid cleansing cosmetic and the oil-based gel cleansing cosmetic of the present invention are as described below.

[0150] (Degree of good makeup removal, ease of rinsing, refreshing feeling after rinsing)

[0151] After 10 female evaluation panel members with makeup experience applied a commercially available powder foundation (made by Chacott Cosmetics Co., Ltd., Chacott UV Foundation EX plus) on the skin, they used the test samples for evaluation for cleansing. For each item, based on the evaluation criteria shown in (1) below, they scored on a scale of 1 to 5. The average score of the 10 evaluators was calculated, and the performance of the cleansing cosmetic was judged according to the four-grade judgment criteria shown in (2) below.

[0152] (1) Evaluation criteria

[0153] 5 points: Good.

[0154] 4 points: Relatively good.

[0155] 3 points: Neither good nor bad.

[0156] 2 points: Poor.

[0157] 1 point: Bad.

[0158] (2) Four-grade judgment criteria

[0159] A: The average score is above 4 points.

[0160] B: The average score is above 3 points and less than 4 points.

[0161] C: The average score is above 2 points and less than 3 points.

[0162] D: The average score is less than 2 points.

[0163] (Eye irritation test)

[0164] 10 female evaluation panel members as above took 2 g of the test sample on a cotton pad, rubbed it around the eyes for 1 minute, and then washed it with warm water. Regarding whether there was irritation to the eyes, they scored on a scale of 1 to 5 according to the evaluation criteria shown in (1) below. The average score of the 10 evaluators was calculated, and the performance of the cleansing cosmetic was judged according to the four-grade judgment criteria shown in (2) below.

[0165] (1) Evaluation criteria

[0166] 5 points: None at all.

[0167] 4 points: Almost none.

[0168] 3 points: A little.

[0169] 2 points: very much.

[0170] 1 point: There is irritation and it is aborted halfway.

[0171] (2) Four-level judgment criteria

[0172] A: The average score is above 4 points.

[0173] B: The average score is above 3 points and less than 4 points.

[0174] C: The average score is above 2 points and less than 3 points.

[0175] D: The average score is less than 2 points.

[0176] Examples 5-9 and Comparative Example 16

[0177] (Oil-based solid cleansing cosmetic)

[0178] Prepare an oil-based solid cleansing cosmetic with the formulation shown in Table 5 according to the following manufacturing sequence. For the obtained oil-based solid cleansing cosmetic, the degree of good makeup removal, ease of rinsing, refreshing feeling after rinsing, and eye irritation were evaluated by the above method. The evaluation results are shown in Table 5.

[0179] (Manufacturing sequence)

[0180] (1) Heat the components 1-9 shown in Table 5 to 85 °C and mix them evenly.

[0181] (2) Fill the mixed solution prepared in (1) above directly into a wide-mouth container (Jar container) at 70 °C in a molten state, and then let it cool to make an oil-based solid cleansing cosmetic.

[0182] [Table 5]

[0183]

[0184] ※8 Trade name PERFORMA SW-87 (manufactured by NuCera Solution Co., Ltd.)

[0185] ※9 Trade name SASOLWAX TITANEL (manufactured by Sasol Co., Ltd.)

[0186] From the results in Table 5, it can be seen that the oil-based solid cleansing cosmetics of Examples 5-9 showed good results in all items. In contrast, for the oil-based solid cleansing cosmetic of Comparative Example 16 using diglycerol isostearate (monoester content 38.1%) with a small monoester content of Specimen I-2, the items of ease of rinsing and refreshing feeling after rinsing were not satisfactory.

[0187] Example 10

[0188] (Oil-based Gel Cleansing Cosmetic)

[0189] Prepare the oil-based gel cleansing cosmetic with the formulation shown in Table 6 according to the following manufacturing sequence. For the obtained oil-based gel cleansing cosmetic, the degree of good makeup removal, ease of rinsing, refreshing feeling after rinsing, and eye irritation were evaluated by the above methods. The evaluation results are shown in Table 6.

[0190] (Manufacturing Sequence)

[0191] (1) Heat the components 1 to 6 shown in Table 6 to 85°C and mix them uniformly.

[0192] (2) Cool the mixture prepared in (1) above to room temperature (25°C) while stirring to obtain an oil-based gel cleansing cosmetic.

[0193] [Table 6]

[0194]

[0195] From the results in Table 6, it can be seen that the oil-based gel cleansing cosmetic of Example 10 showed good results in all items.

[0196] Industrial Applicability

[0197] According to the present invention, there is provided an oil-based cleansing cosmetic having low irritation, excellent stability, makeup removal, and rinsability.

Claims

1. An oily cleansing cosmetic, characterized in that: The oily cleansing cosmetic contains 1 to 40% by mass of glycerol fatty acid ester as component A and 60 to 99% by mass of oil as component B, wherein component A is an ester of a fatty acid having 14 to 22 carbon atoms and diglycerol, the content of diglycerol monoester in the ester is 80% by mass or more, and the HLB value of the ester is 6 or more and less than 8.

2. The oily cleansing cosmetic according to claim 1, wherein The content of diglycerol monoester in the component A is 85% by mass or more, and the content of diglycerol in the component A is 5% by mass or less.

3. The oily cleansing cosmetic according to claim 1 or 2, wherein: The oily cleansing cosmetic does not contain a polyoxyethylene nonionic surfactant.

4. The oily cleansing cosmetic according to claim 1 or 2, wherein: The fatty acid is a branched-chain fatty acid or an unsaturated fatty acid.

5. The oily cleansing cosmetic according to claim 1 or 2, wherein: The fatty acid is isostearic acid.

6. The oily cleansing cosmetic according to claim 1 or 2, wherein: The oily cleansing cosmetic material is cleansing oil, oily solid cleansing cosmetic material or gel cleansing cosmetic material.

7. The oily cleansing cosmetic according to claim 1 or 2, wherein: The component B is an oil component containing ester in a ratio of 50 mass % or more.

8. The oily cleansing cosmetic according to claim 1 or 2, wherein: The oily cleansing cosmetic contains 2 to 35% by mass of the component A and 65 to 98% by mass of the component B.

9. The oily cleansing cosmetic according to claim 1 or 2, wherein: The oily cleansing cosmetic is a solid cosmetic further comprising solid oil in a ratio of 1 to 30% by mass based on the entire cosmetic.

10. The oily cleansing cosmetic according to claim 1 or 2, wherein: The oily cleansing cosmetic is a gel-like cosmetic further comprising an oily gelling agent in a ratio of 0.1 to 20% by mass based on the entire cosmetic.

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