Composition for oily liquid cosmetic and oily liquid cosmetic

Abstract

To provide a composition for oily liquid cosmetic which, despite being in a liquid state, allows for easy structural design, ensures superior productivity, and enables an oily liquid cosmetic formulated with the composition to retain transparency even in low-temperature environments and to remain stable with time, as well as to provide a cleansing cosmetic comprising the composition for oily liquid cosmetic.SOLUTION: There is provided a composition for oily liquid cosmetic, comprising a polyglycerin mixed fatty acid ester that is an ester of: a polyglycerin having an average degree of polymerization in the range of 15 to 50; and a fatty acid including a medium-chain fatty acid having 8 to 10 carbon atoms and at least one of oleic acid and isostearic acid, wherein an esterification ratio of the fatty acid relative to the polyglycerin in the polyglycerin mixed fatty acid ester is in the range of 20% to 30%.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an oily liquid cosmetic composition used for oily liquid cosmetics such as cleansing cosmetics and bath cosmetics, and to an oily liquid cosmetic containing the oily liquid cosmetic composition. [Background technology]

[0002] Cleansing cosmetics have traditionally been used to remove sebum stains and makeup cosmetics such as lipstick, foundation, eye shadow, and mascara from the skin. Cleansing cosmetics are primarily formulated with a high concentration of oily ingredients and surfactants as a cleansing base, and are applied to the skin to blend with sebum stains, makeup stains, and other dirt, transferring the dirt into the oily ingredients, and then removed from the skin by wiping or rinsing with water. Cleansing cosmetics are classified into cream, emulsion, gel, solid, liquid, and other forms, and are selected based on their usability. Among these, oily liquid forms are mainstream, as they blend well with makeup cosmetics and can be easily washed off with water.

[0003] Oil-based liquid cleansing cosmetics are required to generate an oil-in-water emulsion upon contact with water after blending with makeup and other grime, which is then removed from the skin by rinsing with water. Furthermore, the degree of oil-in-water emulsion generation is required to suppress the unpleasant oily feeling that remains on the skin after rinsing with water. This is determined by the structure of the nonionic surfactant used in the cosmetic and the IOB value, which represents the balance between lipophilic and hydrophilic groups.

[0004] Therefore, a cosmetic has been disclosed that generates a fine emulsion by blending a polyglycerol medium-chain fatty acid ester as a co-surfactant in addition to the nonionic surfactants that have traditionally been used in cleansing cosmetics (see Patent Document 1).

[0005] Furthermore, as an oil-based cleansing cosmetic that leaves almost no oily or dry feeling after cleansing, a cosmetic containing a polyglycerol fatty acid ester in which polyglycerol, which contains 20% or less of glycerol polymers with a degree of polymerization of 3 or less, is esterified with a fatty acid having 12 to 22 carbon atoms, has been disclosed (see Patent Document 2).

[0006] However, the polyglycerol medium-chain fatty acid ester used in the cleansing cosmetic of Patent Document 1 has a short fatty acid chain length that forms the lipophilic group, and can be designed as a highly polar nonionic surfactant that easily maintains liquid properties even when the esterification rate is increased. However, because the fatty acid moiety of the lipophilic group does not have an unsaturated bond or a branched structure, it can be difficult to ensure the low-temperature stability of a cleansing cosmetic containing this.

[0007] Furthermore, when the polyglycerol fatty acid ester of Patent Document 2 is used in a cleansing cosmetic composition, it is undesirable to use a straight-chain saturated fatty acid as the fatty acid that forms the lipophilic group, as this results in a solid, and it is preferable to use a branched fatty acid such as isopalmitic acid or isostearic acid, or an unsaturated fatty acid such as oleic acid or linoleic acid, to achieve a liquid. Furthermore, since isostearic acid and oleic acid have long chain lengths, it is difficult to adjust the IOB value by changing the esterification rate when designing the structure as a nonionic surfactant, and a low esterification rate leads to a high viscosity of the composition, making it difficult to discharge from a reactor, which poses productivity problems. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-162691 [Patent Document 2] Japanese Patent Application Publication No. 2019-081729 Summary of the Invention [Problem to be solved by the invention]

[0009] The object of the present invention is to provide an oil-based liquid cosmetic composition that has liquid properties but is easy to design structurally, has excellent productivity, and allows oil-based liquid cosmetics containing the composition to have transparency even in low-temperature environments and be stable over time, and to provide an oil-based liquid cosmetic composition containing the oil-based liquid cosmetic composition. [Means for solving the problem]

[0010] The present invention provides an oily liquid cosmetic composition comprising a polyglycerol mixed fatty acid ester, which is an ester of a polyglycerol having an average degree of polymerization in the range of 15 to 50 and a medium-chain fatty acid having 8 to 10 carbon atoms and a fatty acid including at least one of oleic acid and isostearic acid, wherein the esterification rate of the fatty acid relative to the polyglycerol in the polyglycerol mixed fatty acid ester is in the range of 20 to 30%.

[0011] In the oily liquid cosmetic composition, the medium-chain fatty acids preferably account for 50% or more of the fatty acids in terms of molar ratio.

[0012] The IOB of the oily liquid cosmetic composition is preferably in the range of 0.90 to 1.20.

[0013] The viscosity of the oily liquid cosmetic composition at 80°C is preferably 10,000 mPa·s or less.

[0014] The present invention is an oily liquid cosmetic comprising the oily liquid cosmetic composition.

[0015] In the oil-based liquid cosmetic, the blending amount of water is preferably in the range of 0 to 10% by mass.

[0016] In the oil-based liquid cosmetic, the blending amount of water is preferably 20% by mass or more.

[0017] The oil-based liquid cosmetic is preferably a cleansing cosmetic.

[0018] The oily liquid cosmetic composition is preferably a product that can be used with wet hands and is intended for use in the bathroom. [Effects of the Invention]

[0019] According to the present invention, it is possible to provide an oil-based liquid cosmetic composition that has liquid properties but is easy to design structurally, has excellent productivity, and allows oil-based liquid cosmetics containing the composition to have transparency even in low-temperature environments and are stable over time, as well as an oil-based liquid cosmetic that contains the oil-based liquid cosmetic composition. DETAILED DESCRIPTION OF THE INVENTION

[0020] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following describes an embodiment of the present invention. The embodiment is an example of implementing the present invention, and the present invention is not limited to the embodiment.

[0021] <Oily Liquid Cosmetic Composition> The oily liquid cosmetic composition according to this embodiment contains a polyglycerol mixed fatty acid ester, which is an ester of polyglycerol having an average degree of polymerization in the range of 15 to 50 and a fatty acid containing a medium-chain fatty acid having 8 to 10 carbon atoms and at least one of oleic acid and isostearic acid, and the esterification rate of fatty acid to polyglycerol in the polyglycerol mixed fatty acid ester is in the range of 20 to 30%.

[0022] The present inventors have discovered that by incorporating a polyglycerol mixed fatty acid ester, which is an ester of a polyglycerol having an average degree of polymerization in the range of 15 to 50, a medium-chain fatty acid having 8 to 10 carbon atoms, and a fatty acid containing at least one of oleic acid and isostearic acid, and by setting the esterification rate of fatty acid to polyglycerol in the polyglycerol mixed fatty acid ester to be in the range of 20 to 30%, it is possible to obtain a composition that has liquid properties, is easy to design structurally, has excellent productivity, and oil-based liquid cosmetics such as cleansing cosmetics containing this composition can be transparent even in low-temperature environments and are stable over time. The oil-based liquid cosmetic composition according to this embodiment is a novel compound with excellent productivity, and by using this oil-based liquid cosmetic composition, it is possible to obtain oil-based liquid cosmetics such as cleansing cosmetics that are stable over a long period of time.

[0023] The polyglycerin, which constitutes the polyglycerin mixed fatty acid ester in the oil-based liquid cosmetic composition according to this embodiment and has an average degree of polymerization in the range of 15 to 50, acts as a hydrophilic group in the oil-based liquid cosmetic composition, which is a nonionic surfactant, and is a component that plays a major role in imparting a refreshing feeling to the skin after rinsing with water and in forming reverse micelles using hydrogen bonding via hydroxyl groups.

[0024] The average degree of polymerization of polyglycerol is in the range of 15 to 50, and preferably in the range of 20 to 40. If the average degree of polymerization of polyglycerol is less than 15, the IOB decreases and hydrophilicity becomes insufficient, and if it exceeds 50, the viscosity becomes high, making it difficult to charge into a reactor.

[0025] The fatty acids constituting the polyglycerol mixed fatty acid ester in the oil-based liquid cosmetic composition according to this embodiment include a medium-chain fatty acid having 8 to 10 carbon atoms and at least one of oleic acid and isostearic acid. The medium-chain fatty acid, isostearic acid, and oleic acid are fatty acid residues that form the lipophilic group of the oil-based liquid cosmetic composition. The composition ratio of the fatty acids significantly contributes to the properties of the oil-based liquid cosmetic composition and the low-temperature stability of oil-based liquid cosmetics, such as cleansing cosmetics, that contain the composition.

[0026] Examples of medium-chain fatty acids with 8 to 10 carbon atoms include straight-chain saturated fatty acids such as caprylic acid (also called octanoic acid), pelargonic acid (also called nonanoic acid), and capric acid (also called decanoic acid), straight-chain unsaturated fatty acids such as octenoic acid, nonenoic acid, and decenoic acid, and branched saturated fatty acid such as isocaprylic acid. Note that "8 to 10 carbon atoms" includes the number of carbon atoms in the carboxyl group.

[0027] The esterification ratio of fatty acids to polyglycerin in the polyglycerin mixed fatty acid ester is in the range of 20 to 30%, preferably in the range of 20 to 28%. If the esterification ratio of fatty acids to polyglycerin is less than 20%, the viscosity of the composition increases, and it may be difficult to discharge the composition from a reactor even at high temperatures. If the esterification ratio of fatty acids to polyglycerin exceeds 30%, the composition becomes easier to handle, but the increased lipophilicity reduces polarity, and satisfactory surfactant properties may not be obtained.

[0028] In the polyglycerol mixed fatty acid ester, the ratio of medium-chain fatty acids having 8 to 10 carbon atoms to at least one of oleic acid and isostearic acid is preferably such that the medium-chain fatty acids having 8 to 10 carbon atoms account for 50% or more of the total fatty acids by molar ratio, and more preferably in the range of 50 to 80%. If the medium-chain fatty acids having 8 to 10 carbon atoms account for less than 50% of the total fatty acids by molar ratio, hydrophilicity may decrease and satisfactory surface activity may not be achieved, whereas if it exceeds 80%, the content of groups derived from unsaturated fatty acids and branched fatty acids in the structure decreases, which may affect properties at low temperatures.

[0029] The IOB of the polyglycerol mixed fatty acid ester in the oil-based liquid cosmetic composition according to this embodiment is preferably in the range of 0.90 to 1.20, and more preferably in the range of 0.90 to 1.10. If the IOB of the oil-based liquid cosmetic composition is less than 0.90, its solubility in water may decrease, and if it exceeds 1.20, its solubility in oil may decrease, making it impossible to obtain satisfactory surfactant properties.

[0030] In this embodiment, IOB (Inorganic Organic Balance) is the ratio of inorganic value (IV) to organic value (OV) determined based on the organic conceptual diagram, i.e., "inorganic value (IV) / organic value (OV)=IOB." This is explained in "Organic Conceptual Diagram - Fundamentals and Applications" (by Yoshio Koda, Sankyo Publishing, 1984).

[0031] The polyglycerol mixed fatty acid ester in the oily liquid cosmetic composition according to this embodiment is obtained by an esterification reaction between a polyglycerol and a fatty acid containing a medium-chain fatty acid having 8 to 10 carbon atoms and at least one of oleic acid and isostearic acid, regardless of the synthesis method, and may be further purified according to a known method. For example, it can be produced by adding an acid catalyst to the starting fatty acid and polyglycerol, and carrying out an esterification reaction at normal pressure or reduced pressure at a temperature in the range of 50 to 250°C, for example, 200°C. The origin of the starting fatty acid and the method for producing the polyglycerol are not particularly limited.

[0032] The viscosity of the oil-based liquid cosmetic composition according to this embodiment at 80°C as measured with a Brookfield viscometer is preferably 10,000 mPa·s or less, and more preferably 9,000 mPa·s or less. If the viscosity of the oil-based liquid cosmetic composition at 80°C as measured with a Brookfield viscometer exceeds 10,000 mPa·s, it becomes difficult to discharge the composition from the reactor or to filter it, and productivity may not be ensured. The lower limit of the viscosity of the oil-based liquid cosmetic composition at 80°C as measured with a Brookfield viscometer is preferably as low as possible, and is not particularly limited, but is, for example, 5,000 mPa·s.

[0033] The polyglycerol mixed fatty acid ester in the oily liquid cosmetic composition according to this embodiment can be various types of ester compounds depending on the purpose of its development. That is, by selecting the type of fatty acid or combining two or more different fatty acids, an ester with the desired surfactant properties can be obtained.

[0034] The viscosity and IOB value of the oily liquid cosmetic composition according to this embodiment can be adjusted as desired by appropriately selecting the raw materials, and cosmetics with excellent usability and stability can be provided.

[0035] The oily liquid cosmetic composition according to this embodiment may contain other ingredients such as antioxidants, preservatives, etc. in addition to the polyglycerol mixed fatty acid ester.

[0036] When the oily liquid cosmetic composition according to this embodiment contains components other than the polyglycerol mixed fatty acid ester, the content of the other components is, for example, in the range of 0.1 to 10.0% by mass relative to the amount of the oily liquid cosmetic composition.

[0037] The oily liquid cosmetic composition according to this embodiment can be suitably used in the field of cosmetics, and can be suitably used in oily cosmetics such as oily liquid cosmetics in particular.

[0038] The applications of cosmetics in which the oil-based liquid cosmetic composition according to this embodiment is used are not particularly limited, and the composition can be used as a nonionic surfactant in cleansing cosmetics such as cleansing oil, cleansing liquid, cleansing water, cleansing balm, cleansing gel, cleansing cream, cleansing milk, etc.; bath cosmetics such as bath oil and bath milk, skin care cosmetics such as lotion, serum, cream, emulsion, etc.; UV protection cosmetics such as UV mists, UV gels, UV creams, etc.; hair care cosmetics such as hair oil, hair wax, hair mists, pomade, hair conditioners, etc.; cleansing agents such as hair shampoos, body shampoos, facial washes, etc.

[0039] <Oily liquid cosmetics> An oil-based liquid cosmetic containing the oil-based liquid cosmetic composition according to this embodiment will be described below. The oil-based liquid cosmetic according to this embodiment is a cosmetic containing the oil-based liquid cosmetic composition. The oil-based liquid cosmetic according to this embodiment is, for example, a cosmetic containing the oil-based liquid cosmetic composition and an oil.

[0040] Examples of oil-based liquid cosmetics according to this embodiment include cleansing cosmetics such as cleansing oil, cleansing liquid, cleansing water, cleansing balm, cleansing gel, cleansing cream, and cleansing milk; bath cosmetics such as bath oil and bath milk; skin care cosmetics such as lotion, serum, cream, and emulsion; UV protection cosmetics such as UV mists, UV gels, and UV creams; hair care cosmetics such as hair oil, hair wax, hair mists, pomades, and hair conditioners; and cleansing agents such as hair shampoos, body shampoos, and facial cleansers. Cleansing cosmetics are preferred. Cleansing cosmetics are cosmetics used to remove sebum stains from the skin and makeup cosmetics such as lipstick, foundation, eye shadow, and mascara.

[0041] The oily liquid cosmetic composition such as the cleansing cosmetic composition according to this embodiment can be used with wet hands, for example, and is a product that is intended for use in a bathroom or the like.

[0042] There are no particular limitations on the formulation of oily liquid cosmetics as long as they are oily liquid, and any formulation may be used, such as an emulsion system, a solubilized system, a solution system, a powder dispersion system, a water-oil two-layer system, or a water-oil-powder three-layer system.

[0043] The blending amount of the composition for oil-based liquid cosmetics in oil-based liquid cosmetics such as the cleansing cosmetic according to this embodiment is not particularly limited, but is, for example, about 0.1 to 50 mass% relative to the mass of the oil-based liquid cosmetic, and preferably in the range of 0.5 to 40 mass%. If the blending amount of the composition for oil-based liquid cosmetics in the composition for oil-based liquid cosmetics is less than 0.1 mass% relative to the mass of the oil-based liquid cosmetic, it may not be possible to impart water-washability and may not perform as a cleansing cosmetic, whereas if it exceeds 50 mass%, the formulation may become cloudy or the feel upon application may be impaired.

[0044] The oil-based liquid cosmetic composition such as the cleansing cosmetic composition according to this embodiment may contain, as oil agents, saturated or unsaturated fatty acids and higher alcohols obtained from these saturated or unsaturated fatty acids, squalane, castor oil and derivatives thereof, beeswax, lanolins including liquid lanolin and purified lanolin and derivatives thereof, cholesterol and derivatives thereof, animal and plant-derived oil phase materials such as macadamia nut oil, jojoba oil, carnauba wax, sesame oil, palm oil, candelilla wax, and spermaceti wax, and petroleum-derived and mineral-derived oil phase materials such as paraffin, microcrystalline wax, liquid paraffin, petrolatum, and ceresin. First, silicones such as methylpolysiloxane, methylphenylpolysiloxane, and the like; ester oils such as cetyl ethylhexanoate, isononyl isononanoate, caprylic / capric triglyceride, and caprylic / capric glycerides, acyl amino acid ester oils such as hexyldecyl myristoylmethylaminopropionate and di(phytosteryl / octyldodecyl) lauroyl glutamate; ketones; and any other oily component that is commonly used can be used in combination within a range that does not impair the effect of the oil-based liquid cosmetic composition according to this embodiment as a nonionic surfactant.

[0045] The content of oil in oil-based liquid cosmetics such as the cleansing cosmetic according to this embodiment is not particularly limited, but the preferred range varies depending on the application. For example, the amount of oil in a cleansing oil may be in the range of 35 to 99% by mass, and the amount of oil in a cleansing liquid may be in the range of 15 to 40% by mass. Furthermore, the content of oil in an emulsion cosmetic may be in the range of 0.1 to 15% by mass.

[0046] When the oil-based liquid cosmetic according to this embodiment is an oil-type cleansing cosmetic, it may or may not contain water, and the amount of water is, for example, in the range of 0 to 10% by mass, preferably in the range of 0 to 5% by mass. If the amount of water in the oil-type cleansing cosmetic exceeds 10% by mass, the formation of reverse micelles cannot be maintained, and the formulation may separate.

[0047] When the oil-based liquid cosmetic according to this embodiment is a liquid cleansing cosmetic, it may contain water, and the blending amount of water is, for example, 20% by mass or more, preferably in the range of 20 to 50% by mass. If the blending amount of water in the liquid cleansing cosmetic is less than 20% by mass, it may not be possible to form a bicontinuous microemulsion structure, and if it exceeds 50% by mass, compatibility with makeup cosmetics may decrease.

[0048] The oil-based liquid cosmetic such as the cleansing cosmetic according to this embodiment may contain, in addition to the above-mentioned oil-based liquid cosmetic composition, oil, and water, nonionic surfactants other than those in the above-mentioned oil-based liquid cosmetic composition, such as diglycerin fatty acid esters such as polyglyceryl-2 sesquioleate, polyglyceryl-2 sesquiisostearate, polyglyceryl-2 diisostearate, and polyglyceryl-2 dioleate, triglycerin fatty acid esters such as polyglyceryl-3 coconut oil fatty acid and polyglyceryl-3 triisostearate, polyglyceryl-4 caprate, isostearyl alcohol, and the like. Tetraglycerin fatty acid esters such as polyglyceryl-4 phosphate, hexaglycerin fatty acid esters such as polyglyceryl-6 caprylate, polyglyceryl-6 laurate, polyglyceryl-6 dioleate, decaglycerin fatty acid esters such as polyglyceryl-10 laurate, polyglyceryl-10 diisostearate, polyglyceryl-10 dioleate, eicosaglycerin fatty acid esters such as polyglyceryl-20 hexacaprylate, tetracontaglycerin fatty acid esters such as polyglyceryl-40 pentalaurate, diisostearyl esters such as polyglyceryl-40 pentalaurate, Glycerin fatty acid esters such as glyceryl esters, caprylic / capric glycerides, sorbitan fatty acid esters such as sorbitan oleate, sorbitan isostearate, and sorbitan sesquioleate, polyoxyalkylene alkyl ethers such as laureth-7, ceteth-20, and PPG-2-deceth-7, polyoxyethylene sterol ethers such as PEG-10 phytosterol and cholesterol-20, PEG-8 isostearate, PEG-12 isostearate, PEG-10 oleate, PEG-8 diisostearate, di Examples of nonionic surfactants that are commonly used include polyethylene glycol fatty acid esters such as PEG-12 oleate, polyoxyethylene sorbitol fatty acid esters such as sorbeth-30 tetraoleate, polyoxyethylene sorbitan fatty acid esters such as polysorbate 80, polyoxyethylene hydrogenated castor oils such as PEG-10 hydrogenated castor oil, and polyoxyethylene glycerin fatty acid esters such as PEG-9 glyceryl laurate, PEG-8 glyceryl isostearate, and PEG-20 glyceryl triisostearate.Any of these can be used in combination as long as the effects of the oily liquid cosmetic composition according to this embodiment are not impaired.

[0049] The oil-based liquid cosmetic composition, such as the cleansing cosmetic composition according to this embodiment, may contain an ionic surfactant within a range that does not impair the effects of the oil-based liquid cosmetic composition according to this embodiment. The type of ionic surfactant is not particularly limited, and can be appropriately selected from anionic surfactants, cationic surfactants, and amphoteric surfactants. Examples of ionic surfactants include N-long-chain acyl amino acid salts such as N-long-chain acyl acidic amino acid salts and N-long-chain acyl neutral amino acid salts, N-long-chain fatty acid acyl-N-methyl taurine salts, alkyl sulfates and alkylene oxide adducts, fatty acid amide ether sulfates, metal salts and weak bases of fatty acids, sulfosuccinic acid surfactants, alkyl phosphates and alkylene oxide adducts thereof, anionic surfactants such as alkyl ether carboxylic acids, aliphatic amine salts such as alkylammonium chlorides and dialkylammonium chlorides, quaternary ammonium salts thereof, aromatic quaternary ammonium salts such as benzalkonium, cationic surfactants such as fatty acid acyl arginine esters, and various surfactants such as betaine surfactants such as carboxybetaine, aminocarboxylic acid surfactants, and amphoteric surfactants such as imidazoline amphoteric surfactants.

[0050] The oil-based liquid cosmetic composition, such as the cleansing cosmetic composition according to this embodiment, may contain a moisturizing agent as an aqueous phase component to the extent that the effect of the composition for the oil-based liquid cosmetic composition according to this embodiment is not impaired. Examples of moisturizing agents include polyhydric alcohols such as dipropylene glycol, propylene glycol, 1,3-butylene glycol, propanediol, and glycerin, sugars such as sorbitol and maltitol, amino acids such as glycine, alanine, serine, threonine, arginine, glutamic acid, aspartic acid, leucine, and valine, polyamino acids including polyglutamic acid and polyaspartic acid and salts thereof, polyethylene glycol, polyglycerin, gum arabic, alginates, xanthan gum, hyaluronic acid, hyaluronates, chitin, water-soluble chitin, carboxyvinyl polymers, carboxymethylcellulose, and hydroxyethylcellulose, and lower alcohols such as ethanol and propanol.

[0051] In addition to surfactants and moisturizers, oil-based liquid cosmetics such as cleansing cosmetics according to this embodiment can also contain ingredients commonly used in cosmetics and pharmaceuticals, provided that the effects of the oil-based liquid cosmetic composition according to this embodiment are not impaired. For example, additives such as ultraviolet absorbers, antioxidants, fragrances, colorants, chelating agents, cooling agents, plant extracts, vitamins, pH adjusters, and preservatives can be added as appropriate depending on the intended use.

[0052] The present specification includes the following embodiments. (1) A polyglycerol mixed fatty acid ester is an ester of a polyglycerol having an average degree of polymerization in the range of 15 to 50 and a fatty acid containing a medium-chain fatty acid having a carbon number of 8 to 10 and at least one of oleic acid and isostearic acid, The oily liquid cosmetic composition, wherein the esterification rate of the fatty acid relative to the polyglycerin in the polyglycerin mixed fatty acid ester is in the range of 20 to 30%.

[0053] (2) The oily liquid cosmetic composition according to (1), The oily liquid cosmetic composition comprises medium-chain fatty acids in an amount of 50% or more by molar ratio of the fatty acids.

[0054] (3) The oily liquid cosmetic composition according to (1) or (2), The oil-based liquid cosmetic composition has an IOB in the range of 0.90 to 1.20.

[0055] (4) An oily liquid cosmetic composition according to any one of (1) to (3), The oil-based liquid cosmetic composition has a viscosity of 10,000 mPa·s or less at 80°C.

[0056] (5) An oily liquid cosmetic comprising the composition for oily liquid cosmetics according to any one of (1) to (4).

[0057] (6) The oily liquid cosmetic according to (5), An oil-based liquid cosmetic preparation containing water in an amount ranging from 0 to 10% by mass.

[0058] (7) The oily liquid cosmetic according to (5), An oil-based liquid cosmetic preparation containing water in an amount of 20% by mass or more.

[0059] (8) An oily liquid cosmetic according to any one of (5) to (7), 1. An oil-based liquid cosmetic, characterized in that the oil-based liquid cosmetic is a cleansing cosmetic.

[0060] (9) An oily liquid cosmetic according to any one of (5) to (8), An oily liquid cosmetic that can be used with wet hands and is intended for use in the bathroom. [Example]

[0061] 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 the following examples. In the examples, "parts" means "parts by mass" and "%" means "% by mass" unless otherwise specified.

[0062] The average degree of polymerization of polyglycerol can be calculated from the hydroxyl value by the following formula (i): The hydroxyl value in formula (i) can be measured in accordance with the "Standard Testing Methods for the Analysis of Fats, Oils and Related Compounds" (established by the Japan Oil Chemists' Association). Average degree of polymerization=(112.2×10 3 -18 × hydroxyl value) / (74 × hydroxyl value - 56.1 × 10 3 )···(i)

[0063] The average molecular weight (Mn) of polyglycerol with an average degree of polymerization of 20 was confirmed by a matrix-assisted laser desorption / ionization time-of-flight mass spectrometer (Shimadzu Corporation, MALDI-8030).

[0064] The esterification rate of the obtained polyglycerol mixed fatty acid ester was determined by calculation based on the hydroxyl value of the polyglycerol used in the preparation of the polyglycerol fatty acid ester and the number of moles of the medium-chain fatty acid having 8 to 10 carbon atoms and at least one of oleic acid and isostearic acid. The molar ratio of the medium-chain fatty acid having 8 to 10 carbon atoms to all fatty acids in the obtained polyglycerol mixed fatty acid ester was determined by calculation based on the number of moles of the medium-chain fatty acid having 8 to 10 carbon atoms and at least one of oleic acid and isostearic acid used in the preparation of the polyglycerol fatty acid ester.

[0065] The esterification rate of the polyglycerol mixed fatty acid ester can be calculated by the following formula (ii), where n is the average degree of polymerization of the polyglycerol, n+2 is the number of hydroxyl groups in the polyglycerol, and M is the number of moles of fatty acid added to 1 mole of the polyglycerol. Esterification rate (%) = (M / (n+2)) × 100 (ii)

[0066] [Preparation of polyglycerol fatty acid esters] <Synthesis Example 1> 246.4 g of polyglycerol (average molecular weight: 1516) with an average degree of polymerization of 20, 103.2 g (0.72 mol) of caprylic acid, which is a medium-chain fatty acid with 8 carbon atoms, and 50.4 g (0.18 mol) of oleic acid were placed in a reaction vessel, and 0.12 g of sodium hydroxide was added. After that, the reaction was carried out in a nitrogen atmosphere at 250°C for 3.5 hours, yielding 338 g of "hexa(caprylic acid / oleic acid) polyglyceryl-20" with an esterification rate (ES) of 28%, medium-chain fatty acids with 8 to 10 carbon atoms accounting for 80% of all fatty acids in molar ratio, and an IOB of 0.98.

[0067] <Synthesis Example 2> 249.6 g of polyglycerol with an average degree of polymerization of 20, 65.2 g (0.45 mol) of caprylic acid, and 85.2 g (0.30 mol) of oleic acid were placed in a reaction vessel, and 0.20 g of sodium hydroxide was added. The reaction was carried out in a nitrogen atmosphere at 250°C for 4 hours, yielding 336 g of "penta(caprylic acid / oleic acid)polyglyceryl-20" with an esterification rate of 23%, medium-chain fatty acids with 8 to 10 carbon atoms accounting for 60% of all fatty acids in terms of molar ratio, and an IOB of 0.99.

[0068] <Synthesis Example 3> 236.4 g of polyglycerol with an average degree of polymerization of 20, 61.6 g (0.36 mol) of capric acid, which is a medium-chain fatty acid having 10 carbon atoms, and 102.0 g (0.36 mol) of isostearic acid were placed in a reaction vessel, and 0.16 g of sodium hydroxide was added. After that, the reaction was carried out in a nitrogen atmosphere at 250°C for 4 hours, yielding 330 g of "penta(capric acid / isostearate)polyglyceryl-20" with an esterification rate of 23%, medium-chain fatty acids having 8 to 10 carbon atoms accounting for 50% of all fatty acids in molar ratio, and an IOB of 0.97.

[0069] <Synthesis Example 4> 256.4 g of polyglycerol with an average degree of polymerization of 40, 78.0 g (0.54 mol) of caprylic acid, and 65.6 g (0.23 mol) of oleic acid were placed in a reaction vessel, and 0.12 g of sodium hydroxide was added. The reaction was carried out in a nitrogen atmosphere at 250°C for 3.5 hours, yielding 329 g of "deca (caprylic acid / oleic acid) polyglyceryl-40" with an esterification rate of 24%, medium-chain fatty acids with 8 to 10 carbon atoms accounting for 70% of all fatty acids by molar ratio, and an IOB of 1.00.

[0070] <Synthesis Example 5> 250.8 g of polyglycerol with an average degree of polymerization of 20, 39.6 g (0.27 mol) of caprylic acid, and 109.6 g (0.64 mol) of capric acid were placed in a reaction vessel and reacted for 3 hours at 250°C in a nitrogen stream without a catalyst, yielding 339 g of "hexa(caprylic acid / capric acid) polyglyceryl-20" with an esterification rate of 28%, 100% of all fatty acids in terms of molar ratio of 8 to 10 carbon atoms, and an IOB of 1.06.

[0071] <Synthesis Example 6> 267.2 g of polyglycerol with an average degree of polymerization of 20, 35.2 g (0.24 mol) of caprylic acid, and 97.6 g (0.57 mol) of capric acid were placed in a reaction vessel and reacted for 3 hours at 250°C in a nitrogen stream without a catalyst, yielding 339 g of "penta(caprylic acid / capric acid) polyglyceryl-20" with an esterification rate of 23%, 100% of all fatty acids in terms of molar ratio of 8 to 10 carbon atoms, and an IOB of 1.17.

[0072] <Synthesis Example 7> 264.4 g of polyglycerol with an average degree of polymerization of 20 and 135.6 g (0.48 mol) of oleic acid were placed in a reaction vessel, and 0.4 g of sodium hydroxide was added. The reaction was then carried out in a nitrogen atmosphere at 250°C for 3 hours, yielding 319 g of "polyglyceryl-20 trioleate" with an esterification rate of 14%, no medium-chain fatty acids with 8 to 10 carbon atoms as lipophilic groups (i.e., 0% of all fatty acids in terms of molar ratio), and an IOB of 1.08.

[0073] <Synthesis Example 8> 255.6 g of polyglycerol with an average degree of polymerization of 40 and 144.4 g (1.0 mol) of caprylic acid were placed in a reaction vessel, and 0.12 g of sodium hydroxide was added. The reaction was carried out in a nitrogen atmosphere at 250°C for 4 hours, yielding 330 g of "polyglyceryl-40 tridecacaprylate" with an esterification rate of 31%, medium-chain fatty acids with 8 to 10 carbon atoms accounting for 100% of all fatty acids in terms of molar ratio, and an IOB of 0.92.

[0074] In the following examples and comparative examples, the following items were evaluated.

[0075] "viscosity" The viscosity of the polyglycerol fatty acid esters of Synthesis Examples 1 to 8 at 80°C was measured using a B-type viscometer, a BM-type viscometer TVB-10M (12 rpm, rotor No. 3) manufactured by Toki Sangyo Co., Ltd., and the productivity was evaluated according to the following evaluation criteria. The results are shown in Table 1.

[0076] (Evaluation criteria) 〇: Transparent or suspension-like with a viscosity of 10,000 mPa·s or less ×: Viscosity is 10,000 mPa·s or more, and the product is transparent or in a suspension state, which poses productivity issues.

[0077] [Table 1]

[0078] As shown in Table 1 above, the polyglycerol oleate of Synthesis Example 7, which does not contain medium-chain fatty acids as ester groups and has an esterification rate of less than 20%, exhibits high viscosity even at 80°C, whereas the compounds of Synthesis Examples 1 to 6 and 8, in which medium-chain fatty acids having 8 to 10 carbon atoms account for 50% or more of the total fatty acids in terms of molar ratio, can be easily discharged from the reactor or filtered.

[0079] [Preparation of nonionic soluble oil-based liquid cosmetic] A water-free oil-based liquid cosmetic was prepared by heating and dissolving 10% by mass of the polyglycerol fatty acid esters of Synthesis Examples 1 to 8 and 12% by mass of decaglyceryl dioleate (polyglyceryl-10 dioleate, EMALEX DOG-10 / manufactured by Nippon Emulsion Co., Ltd.) as a nonionic surfactant (22% by mass in total) and 78% by mass of cetyl ethylhexanoate (EMALEX CC-168 / manufactured by Nippon Emulsion Co., Ltd.) as an oil agent at 70°C, followed by stirring and cooling to 30°C.

[0080] The oily liquid cosmetics thus prepared were evaluated for stability at 25°C and -5°C, stain removability, and feel after rinsing with water according to the following evaluation criteria. The results are shown in Table 2. For preparations for which the stability evaluation at 25°C and / or -5°C was "x", evaluation of stain removability and feel after rinsing with water was not performed and the evaluation was recorded as "-".

[0081] "Stability" 50 g of the oily liquid cosmetic was placed in a screw-cap medium bottle (volume 100 ml) and left to stand in a thermostatic bath at 25°C and -5°C for 30 days, respectively, before evaluation.

[0082] (Evaluation criteria) 〇: No turbidity or separation is observed and transparency is maintained. △: No separation observed, but cloudy or solidified ×: Separated

[0083] "How well it absorbs dirt and feels after rinsing" An appropriate amount of lipstick (product name: Proof Shiny Rouge 50 / Isehan Co., Ltd.) was applied to the inside of the forearm, and 5 g of the oil-based liquid cosmetic of the Example or Comparative Example was dropped onto it. The cleansing motion was performed up and down with the fingers 10 times, and the degree to which the makeup stains were absorbed was evaluated. The makeup stains were then rinsed off with running water, and the ease of rinsing them off and the refreshing feeling after use were evaluated. (Evaluation criteria) 〇: Blends well with makeup and leaves no oily feeling after rinsing △: Blends well with makeup stains, but leaves a slight stickiness after rinsing ×: Does not blend with makeup stains or remains sticky after rinsing

[0084] [Table 2]

[0085] As shown in Table 2 above, the oil-based liquid cosmetics of Examples 1 to 4, which contain polyglycerol fatty acid esters having medium-chain fatty acid residues and isostearic acid or oleic acid residues as lipophilic groups, are thought to have excellent compatibility with oils due to the balance of carbon chain lengths, and are also able to maintain clear liquid properties not only at 25° C. but also at −5° C. due to the iso-branching and double bonds in the fatty acid structure. Conversely, the oil-based liquid cosmetics of Comparative Examples 1, 2, and 4, which contain polyglycerol fatty acid esters having only medium-chain fatty acid residues as lipophilic groups, and Comparative Example 3, which contain polyglycerol fatty acid esters having only oleic acid residues as lipophilic groups, are found to become cloudy at −5° C. and have low compatibility with oils, making it difficult to ensure stability, even when their IOBs are in the range of 0.90 to 1.20.

[0086] [Preparation of reverse micelle-forming oily liquid cosmetic] A water-containing oil-based liquid cosmetic was prepared by heating and dissolving 10% by mass of the polyglycerol fatty acid esters of Synthesis Examples 2 and 5, 10% by mass of diglyceryl sesquioleate (polyglyceryl-2 sesquioleate, EMALEX SOG-2, manufactured by Nippon Emulsion Co., Ltd.) as a nonionic surfactant, 50% by mass of cetyl ethylhexanoate (EMALEX CC-168, manufactured by Nippon Emulsion Co., Ltd.) as an oil agent, 23% by mass of isononyl isononanoate (EMALEX NINI-99, manufactured by Nippon Emulsion Co., Ltd.) and 5% by mass of methylpolysiloxane (KF-96A-10cs, manufactured by Shin-Etsu Chemical Co., Ltd.) at 70°C, followed by dropwise addition of 2% by mass of water, stirring, and cooling with stirring to 30°C.

[0087] The oil-based liquid cosmetics thus prepared were evaluated for stability at 25°C and -5°C according to the above evaluation criteria, and for re-emulsification ability according to the following evaluation criteria. The results are shown in Table 3. For preparations for which the stability evaluation at 25°C and / or -5°C was "x", re-emulsification ability was not evaluated and the evaluation was entered as "-".

[0088] "Re-emulsifying property" 0.5 g of the oily liquid cosmetic was applied evenly to artificial leather, and the degree of cloudiness when 3 g of purified water was dropped onto it was visually confirmed and evaluated.

[0089] (Evaluation criteria) 〇: Emulsifies into a cloudy white △: Emulsifies to a slightly cloudy white ×: Not emulsified into cloudy white

[0090] [Table 3]

[0091] As shown in Table 3 above, the oil-based liquid cosmetic of Example 5, which contains a polyglycerol fatty acid ester having a medium-chain fatty acid residue and an oleic acid residue as a lipophilic group, is thought to have excellent stability, as it forms reverse micelles in oil with the added purified water, encapsulating the nonionic surfactant diglyceryl sesquioleate and the polyglycerol fatty acid ester of Synthesis Example 2. Conversely, Comparative Example 5, which uses the polyglycerol fatty acid ester of Synthesis Example 5, whose fatty acid composition is composed only of medium-chain fatty acids, is thought to have a short lipophilic group chain length and is therefore unable to form stable reverse micelles in oil.

[0092] [Preparation of oily liquid cosmetics that can be used with wet hands] A water-resistant oil-based liquid cosmetic was prepared by heating and dissolving 20% ​​by mass of the polyglycerol fatty acid esters of Synthesis Examples 1, 4, 7, and 8, 10% by mass of hexaglyceryl dioleate (polyglyceryl-6 dioleate, EMALEX DVG-6, manufactured by Nippon Emulsion Co., Ltd.) as a nonionic surfactant, 44% by mass of cetyl ethylhexanoate (EMALEX CC-168, manufactured by Nippon Emulsion Co., Ltd.) as an oil, 20% by mass of tri(caprylic / capric)glyceryl (TCG-M, manufactured by Kokyu Alcohol Kogyo Co., Ltd.), and 3% by mass of hexyldecyl myristoylmethylaminopropionate (AMITER MA-HD, manufactured by Nippon Emulsion Co., Ltd.) at 70°C, followed by dropwise addition of 1% by mass of 1,3-butylene glycol (manufactured by Daicel Corporation) as a moisturizer and 2% by mass of water, followed by stirring and cooling to 30°C.

[0093] The oil-based liquid cosmetics thus prepared were evaluated for stability at 25°C and -5°C according to the above evaluation criteria, and for water resistance according to the following evaluation criteria. The results are shown in Table 4. For preparations for which the stability evaluation at 25°C and / or -5°C was "x", water resistance was not evaluated and the evaluation was entered as "-".

[0094] "water resistance" Assuming use in a bathroom, 20 g of oil-based liquid cosmetic was placed in a screw-top medium bottle (100 ml capacity), and water was added little by little while stirring. The limiting water content at which transparency was maintained was determined visually using the formula below, and the suitability for use in an environment where hands are wet was evaluated. Water addition rate (%) = water addition amount (g) / 20×100

[0095] (Evaluation criteria) 〇: The water content is 30% or more, so it can be used in the bathroom. ×: The water content is less than 30%, making it difficult to use in the bathroom.

[0096] [Table 4]

[0097] As shown in Table 4 above, the oil-based liquid cosmetics of Examples 6 and 7, which contained the polyglycerol fatty acid esters of Synthesis Examples 1 and 4 having medium-chain fatty acid residues and isostearic acid or oleic acid residues as lipophilic groups, not only exhibited excellent temperature stability, but also had water content of 30% by mass or more, making them suitable for use in the bathroom. Conversely, the oil-based liquid cosmetics of Comparative Example 6, which used a polyglycerol fatty acid ester having only oleic acid residues as lipophilic groups, and Comparative Example 7, which used a polyglycerol fatty acid ester having only medium-chain fatty acid residues as lipophilic groups, had stability problems.

[0098] <Preparation of oil-based liquid cosmetic having both oil and water bicontinuous phases> The polyglycerol fatty acid esters of Synthesis Examples 1, 4, 5, and 8, 30% by mass of hexaglyceryl dioleate (EMALEX DVG-6, manufactured by Nippon Emulsion Co., Ltd.) as a nonionic surfactant, 20% by mass of cetyl ethylhexanoate (EMALEX CC-168, manufactured by Nippon Emulsion Co., Ltd.) as an oil agent, and 10% by mass of isononyl isononanoate (EMALEX NINI-99, manufactured by Nippon Emulsion Co., Ltd.) were heated and dissolved at 70°C, and then 2% by mass of 1,2-pentanediol (Diol PD, manufactured by Kokyu Alcohol Kogyo Co., Ltd.), 8% by mass of dipropylene glycol (DPG-RF, manufactured by ADEKA Corporation) as a moisturizer, and 30% by mass of water were added dropwise and stirred, and the mixture was cooled with stirring to 30°C to prepare an oil-based liquid cosmetic having a bicontinuous microemulsion structure.

[0099] The prepared oil-based liquid cosmetics were evaluated for stability at 25°C and -5°C according to the above evaluation criteria, and for light transmittance and pigment dispersibility according to the following evaluation criteria. The results are shown in Table 5. For preparations that received an "X" rating for stability at 25°C and / or -5°C, evaluation of light transmittance and pigment dispersibility was not performed and the result was recorded as "-".

[0100] Whether or not an oil-based liquid cosmetic preparation has an isotropic single liquid phase that is a bicontinuous microemulsion structure was confirmed by measuring the light transmittance using a polarizing plate and the dispersibility of aqueous and oil-based dyes.

[0101] "Light transparency" It can be distinguished from optically anisotropic liquid crystals by evaluating whether or not light is transmitted when an oily liquid cosmetic product in a transparent glass bottle is placed between two polarizing plates placed perpendicular to each other.

[0102] (Evaluation criteria) 〇: No light transmission, optically isotropic ×: Light transmittance, optical anisotropy

[0103] "Pigment dispersibility" 10 g of oil-based liquid cosmetic is weighed into a test tube, and 0.05 g of a water-soluble dye (Blue No. 1, 0.1% aqueous solution) or an oil-soluble dye (β-carotene, hexyldecyl myristoylmethylaminopropionate 1% solution) is dropped into it, and the dispersed phase state is evaluated visually.

[0104] (Evaluation criteria) ○: Both water-soluble and oil-soluble dyes were added and the mixture became transparent, indicating a continuous phase of water and oil. ×: Only either the water-soluble dye or the oil-soluble dye is transparent, and the continuous phase is water or oil.

[0105] [Table 5]

[0106] As shown in Table 5 above, the oil-based liquid cosmetics of Examples 8 and 9, which contained the polyglycerol fatty acid esters of Synthesis Examples 1 and 4, each of which had a medium-chain fatty acid residue and an isostearic acid or oleic acid residue as a lipophilic group, had excellent temperature stability and were able to contain large amounts of water and polyhydric alcohols as aqueous phase components. Furthermore, they were optically isotropic, capable of transparently dispersing water-soluble and oil-soluble dyes, with water and oil forming a continuous phase. Conversely, the oil-based liquid cosmetics of Comparative Examples 8 and 9, which used polyglycerol fatty acid esters having only medium-chain fatty acid residues as a lipophilic group, had stability problems.

[0107] (Prescription example) Below, Table 6 shows a formulation example of olive cleansing oil as a cleansing cosmetic product using the oil-based liquid cosmetic composition of the Example, Table 7 shows a formulation example of cloudy cleansing oil as a cleansing cosmetic product using the oil-based liquid cosmetic composition of the Example, Table 8 shows a formulation example of clear cleansing oil as a cleansing cosmetic product using the oil-based liquid cosmetic composition of the Example, Table 9 shows a formulation example of cleansing liquid as a cleansing cosmetic product using the oil-based liquid cosmetic composition of the Example, and Table 10 shows a formulation example of bath oil as a bath cosmetic product using the oil-based liquid cosmetic composition of the Example. The present invention is not limited in any way by these formulation examples.

[0108] [Table 6]

[0109] [Table 7]

[0110] [Table 8]

[0111] [Table 9]

[0112] [Table 10]

[0113] As described above, the oil-based liquid cosmetic compositions of the Examples were easy to design structurally while retaining liquid properties, and were highly productive. Oil-based liquid cosmetics containing these oil-based liquid cosmetic compositions were able to retain transparency even in low-temperature environments and were stable over time.

Claims

1. The present invention comprises a polyglycerol mixed fatty acid ester, which is an ester of a polyglycerol having an average degree of polymerization in the range of 15 to 50 and a fatty acid including a medium-chain fatty acid having a carbon number of 8 to 10 and at least one of oleic acid and isostearic acid, The oily liquid cosmetic composition is characterized in that the esterification rate of the fatty acid relative to the polyglycerin in the polyglycerin mixed fatty acid ester is in the range of 20 to 30%.

2. The oily liquid cosmetic composition according to claim 1, An oily liquid cosmetic composition, characterized in that the medium-chain fatty acids account for 50% or more of the fatty acids in terms of molar ratio.

3. The oily liquid cosmetic composition according to claim 1, The oil-based liquid cosmetic composition has an IOB in the range of 0.90 to 1.

20.

4. The oily liquid cosmetic composition according to claim 1, An oil-based liquid cosmetic composition, characterized in that the viscosity of the oil-based liquid cosmetic composition at 80°C is 10,000 mPa·s or less.

5. An oily liquid cosmetic comprising the oily liquid cosmetic composition according to any one of claims 1 to 4.

6. The oily liquid cosmetic according to claim 5, An oil-based liquid cosmetic preparation characterized in that the blending amount of water is in the range of 0 to 10 mass %.

7. The oily liquid cosmetic according to claim 5, An oily liquid cosmetic preparation characterized in that the blending amount of water is 20% by mass or more.

8. The oily liquid cosmetic according to claim 5, 1. An oil-based liquid cosmetic, characterized in that the oil-based liquid cosmetic is a cleansing cosmetic.

9. The oily liquid cosmetic according to claim 5, This oily liquid cosmetic is characterized in that it can be used with wet hands and is a product intended for use in a bathroom.

Images