Cosmetic composition

Abstract

To provide a cosmetic composition comprising an oil-soluble active ingredient, in which the stability of an oil-soluble active ingredient during high-temperature storage is enhanced, a change in appearance color is suppressed, and further a water-based cosmetic exhibiting high transparency and a non-sticky sense of use can be obtained by preparing an aqueous solution using the composition.SOLUTION: There is provided a cosmetic composition comprising the following components (A) to (D), wherein the mass ratio (B) / (D) of the content of the component (B) to the content of the component (D) is 0.01 to 5: (A) 40 to 99 mass% of a polyhydric alcohol having a carbon number of 3 to 6 and a valence of 2 to 3, (B) 0.001 to 30 mass% of an oil-soluble active ingredient, (C) 0.001 to 5 mass% of an ascorbic acid salt and / or a polyphenol and (D) 0.01 to 10 mass% of a copolymer having a structural unit based on 2-(meth)acryloyloxyethyl phosphorylcholine and a structural unit based on an alkyl (meth)acrylate.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a cosmetic composition containing an oil-soluble active ingredient. [Background technology]

[0002] Skin care generally begins with hydration with lotion, followed by the use of cosmetics containing oils such as emulsions and creams to prevent dryness and roughness of the skin. In addition, cosmetics containing active ingredients are used to achieve beauty effects such as whitening and anti-wrinkle. Oil-soluble active ingredients in particular are widely used because they have high permeability to the skin. In general, oils are subject to deterioration due to oxidation, such as odor, discoloration, and loss of functionality, and these deteriorations are particularly accelerated by heat and light. For this reason, various methods have been proposed to maintain the quality of oils in cosmetics and cosmetic raw materials.

[0003] For example, Patent Document 1 proposes a method of dissolving an oil agent in (caprylic / capric / succinic acid) triglyceride, thereby causing the oil agent to exist in a spherical form in the aqueous phase, reducing contact with air and preventing oxidative deterioration of the oil agent. Furthermore, Patent Document 2 proposes a method of preventing decomposition of an oily agent, which easily deteriorates, by encapsulating the oily agent in a capsule that combines a polymer gelling agent and a water-soluble polyvalent metal salt. However, although these methods improve the stability of oils, they have limitations on the appearance of cosmetics, such as making aqueous cosmetics appear cloudy.

[0004] Here, water-based cosmetics are preferred for their refreshing feel while maintaining a high moisture content in the skin. Oils are sometimes blended into water-based cosmetics for various purposes, but when added in amounts sufficient to exert their functions, stickiness may occur due to the oil itself or surfactants required for solubilizing the oil, which may degrade the feel of the water-based cosmetics when used. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2016-222637 [Patent Document 2] Japanese Patent Application Publication No. 2019-131504 Summary of the Invention [Problem to be solved by the invention]

[0006] The problem to be solved by the present invention is to provide a cosmetic composition containing an oil-soluble active ingredient, which has improved stability of the oil-soluble active ingredient during high-temperature storage and suppresses changes in external color, and further, which, by using this composition to prepare an aqueous solution, can give an aqueous cosmetic composition that has high transparency and provides a less sticky feel when used. [Means for solving the problem]

[0007] In order to solve the above problems, the present inventors conducted extensive research and found that the above problems can be solved by adding predetermined amounts of a specific acrylic copolymer and a specific compound having antioxidant properties to a cosmetic composition containing predetermined amounts of a specific alcohol and an oil-soluble active ingredient, respectively, and thus completed the present invention.

[0008] That is, the present invention provides a cosmetic composition containing the following components (A) to (D), in which the mass ratio (B / D) of the content of component (B) to the content of component (D) is 0.01 to 5: (A) 40 to 99% by mass of a polyhydric alcohol having 3 to 6 carbon atoms and a valence of 2 to 3 (B) 0.001 to 30% by mass of an oil-soluble active ingredient (C) 0.001 to 5% by mass of ascorbate and / or polyphenol (D) 0.01 to 10% by mass of a copolymer having a constitutional unit represented by the following formula (1) and a constitutional unit represented by the following formula (2): [ka] (In the formula, R 1 represents a hydrogen atom or a methyl group. [ka] (In the formula, R 2 represents a hydrogen atom or a methyl group, and m represents an integer of 3 to 21. [Effects of the Invention]

[0009] The cosmetic composition of the present invention enhances the stability of the oil-soluble active ingredient during high-temperature storage and can suppress changes in the appearance color of the cosmetic composition. Furthermore, by preparing an aqueous solution using this composition, it is possible to obtain an aqueous cosmetic composition that has high transparency and provides a less sticky feel when used. DETAILED DESCRIPTION OF THE INVENTION

[0010] Although the embodiments of the present invention will be described below, the present invention is not limited to the following embodiments and can be modified in various ways without departing from the gist of the present invention. In this specification, numerical ranges defined using the symbol "to" are inclusive of the numerical values ​​at both ends (upper and lower limits) of the symbol "to." For example, "2 to 4" means 2 or more and 4 or less.

[0011] The cosmetic composition of the present invention contains at least the following components (A), (B), (C) and (D). Each component will be explained below. In this specification, the content of each component refers to the content when the total amount of the cosmetic composition of the present invention is taken as 100% by mass. Furthermore, when the composition contains multiple substances corresponding to each component, the content of each component in the composition refers to the total content of the multiple substances present in the composition.

[0012] [Component (A)] Component (A) used in the present invention is a polyhydric alcohol having 3 to 6 carbon atoms and a valence of 2 to 3. Examples of such polyhydric alcohols include glycerin, pentylene glycol, 1,3-butylene glycol, propylene glycol, 1,3-propanediol, dipropylene glycol, hexylene glycol, and isoprene glycol. Among these, glycerin, pentylene glycol, 1,3-butylene glycol, propylene glycol, and 1,3-propanediol are preferred, and glycerin and 1,3-butylene glycol are more preferred. These polyhydric alcohols can be produced by known methods; for example, glycerin can be produced by purifying an aqueous solution obtained by hydrolyzing fats and oils, for example, by distillation. As component (A), one selected from the above polyhydric alcohols can be used alone, or two or more can be used in combination.

[0013] When glycerin and 1,3-butylene glycol (BG) are used in combination, the mass ratio of glycerin:BG is preferably 40:60 to 60:40, and more preferably 45:55 to 55:45. When the mass ratio of glycerin:BG is within the above range, production stability can be further improved when an emulsion is prepared under high-pressure conditions using the cosmetic composition of the present invention.

[0014] The content of component (A) is 40 to 99% by mass, preferably 45 to 97% by mass, and more preferably 50 to 95% by mass, based on the total amount of the cosmetic composition. If the content of component (A) is too low, the transparency of the appearance of an aqueous solution prepared from this composition may decrease. If the content of component (A) is too high, the effects of the oil-soluble active ingredient may not be fully achieved, and the product may feel excessively sticky, resulting in a poor usability.

[0015] [Component (B)] The component (B) used in the present invention is an oil-soluble active ingredient. "Oil-soluble" means that the solubility in water is extremely low, for example, the solubility is less than 1 g per 100 g of water at room temperature (25°C), or the octanol / water partition coefficient (LogPow) is greater than 1. "Active ingredient" means the main component that exerts the desired effect, and does not include oil-soluble components used solely as a base or solvent. Hereinafter, component (B) will also be referred to as oil-soluble active ingredient (B).

[0016] The oil-soluble active ingredient (B) is not particularly limited, and examples include oil-soluble derivatives of vitamin C such as ascorbyl monostearate, ascorbyl monopalmitate, ascorbyl dipalmitate, ascorbyl triisopalmitate, ascorbyl tetraisopalmitate, and ascorbyl tetrahexyldecanoate; vitamin E and its derivatives such as tocopherol and tocopherol acetate; vitamin A and its derivatives such as retinol, retinal, and retinol palmitate; ceramides and their analogs; stearyl glycyrrhetinate; isopropylmethylphenol; and heparinoids. Among these, oil-soluble vitamins such as vitamin A, vitamin C, vitamin E, and their derivatives are preferred, as they are highly effective as active ingredients and are prone to deterioration. The oil-soluble active ingredient (B) can be used alone or in combination of two or more. As ingredient (B), one selected from the above oil-soluble active ingredients can be used alone or in combination of two or more.

[0017] The content of the oil-soluble active ingredient (B) is 0.001 to 30% by mass, preferably 0.005 to 20% by mass, and more preferably 0.01 to 10% by mass, based on the total amount of the cosmetic composition. If the content of the oil-soluble active ingredient (B) is too low, it may be difficult to obtain the effects of the oil-soluble active ingredient (B). On the other hand, if the content of the oil-soluble active ingredient (B) is too high, the oil-soluble active ingredient (B) may cause stickiness, resulting in a poor feel in use, or the transparency of the appearance of an aqueous solution prepared from this composition may decrease.

[0018] [Component (C)] The component (C) used in the present invention is an ascorbate and / or a polyphenol, and either or both of the ascorbate and the polyphenol can be used. The ascorbate salt is not particularly limited, but examples thereof include alkali metal salts or alkaline earth metal salts of ascorbic acid such as sodium ascorbate and calcium ascorbate, and their L-, D- and racemic forms. Of these, sodium ascorbate and calcium ascorbate are preferred. The ascorbate salts may be used alone or in combination of two or more.

[0019] Polyphenols have multiple phenolic hydroxy groups (hydroxy groups bonded to aromatic rings such as benzene rings and naphthalene rings) in their molecules and are contained as components in the fruits, leaves, flowers, bark, etc. of plants. In the present invention, polyphenols purified or synthesized from plant extracts can be used, and plant extracts containing polyphenols can also be used. Polyphenols can be used alone or in combination of two or more. Examples of polyphenols include flavonoids, simple phenols, hydrolyzable tannins, and condensed tannins. Among these, simple phenols are preferred, and hydroxytyrosol is more preferred.

[0020] The content of component (C) is 0.001 to 5% by mass, preferably 0.01 to 1% by mass, and more preferably 0.05 to 0.5% by mass, based on the total amount of the cosmetic composition. If the content of component (C) is too low, it may be difficult to achieve the effect of stabilizing the oil-soluble active ingredient during high-temperature storage, or the cosmetic composition may change in color. If the content of component (C) is too high, the cosmetic composition may change in color or become sticky, resulting in a poor feel in use.

[0021] [Component (D)] Component (D) used in the present invention is a copolymer having a constitutional unit represented by the following formula (1) and a constitutional unit represented by the following formula (2). Hereinafter, component (D) will also be referred to as copolymer (D).

[0022] [ka] (In the formula, R 1 represents a hydrogen atom or a methyl group.

[0023] The structural unit represented by the above formula (1) is a structural unit based on 2-(meth)acryloyloxyethyl phosphorylcholine, where "(meth)acryloyl" means acryloyl or methacryloyl.

[0024] [ka] (In the formula, R 2 represents a hydrogen atom or a methyl group, and m represents an integer of 3 to 21.

[0025] The structural unit represented by the above formula (2) is a structural unit based on alkyl (meth)acrylate, where "(meth)acrylic acid" means acrylic acid or methacrylic acid. The alkyl group in the alkyl (meth)acrylate is a linear or branched alkyl group having 4 to 22 carbon atoms, and examples thereof include butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, etc. Of these, linear alkyl groups such as butyl, octyl, decyl, dodecyl, and octadecyl are preferred, with an octadecyl group being more preferred. m is an integer of 3 to 21, preferably an integer of 5 to 21, more preferably an integer of 10 to 21, and even more preferably an integer of 15 to 20.

[0026] In the copolymer (D), the ratio of the content of the structural unit represented by the above formula (1) to the content of the structural unit represented by the above formula (2) ([structural unit represented by formula (1)]:[structural unit represented by formula (2)]) (k:l) is preferably 9:1 to 1:9, more preferably 8:2 to 2:8, in molar ratio.

[0027] If the ratio (l / k) (molar ratio) of the content of the structural unit represented by formula (2) to the content of the structural unit represented by formula (1) is too small, the solubilizing power of the oil-soluble active ingredient (B) may decrease, and the stability of the cosmetic composition may decrease. On the other hand, if the ratio (l / k) is too large, the hydrophobicity may be too high, and the solubility of component (A) may decrease, and the stability of the cosmetic composition may decrease.

[0028] The weight-average molecular weight of copolymer (D) is usually 10,000 to 1,000,000, preferably 30,000 to 900,000, more preferably 50,000 to 800,000, still more preferably 100,000 to 700,000, and particularly preferably 200,000 to 600,000. If the weight-average molecular weight of copolymer (D) is too low, the feeling in use may be reduced and stickiness may occur, whereas if the weight-average molecular weight of copolymer (D) is too high, handling may become difficult. The weight average molecular weight of the copolymer (D) is measured by gel permeation chromatography (GPC) and is expressed as a molecular weight converted into polyethylene glycol.

[0029] The polymerization form of the copolymer (D) is not particularly limited, and it may be a random copolymer or a block copolymer, but a random copolymer is preferred. Furthermore, the copolymer (D) is usually a binary copolymer consisting of a structural unit represented by the above formula (1) and a structural unit represented by the above formula (2), but it may also be a copolymer containing other structural units in addition to the structural units represented by formulas (1) and (2). The other structural units that may be contained in the copolymer (D) can usually be appropriately selected from those that can serve as structural units of the copolymer (D) within a range that does not affect the effects of the present invention. Examples of monomers that form the other structural units include (meth)acrylic acid esters having a lower alkyl group with 1 to 3 carbon atoms, such as methyl (meth)acrylate and ethyl (meth)acrylate; (meth)acrylic acid esters having a cyclic alkyl group, such as cyclohexyl (meth)acrylate; (meth)acrylic acid esters containing an aromatic group, such as benzyl (meth)acrylate and phenoxyethyl (meth)acrylate; styrene-based monomers, such as styrene, methylstyrene, and chloromethylstyrene; vinyl ether-based monomers, such as methyl vinyl ether and butyl vinyl ether; and vinyl ester-based monomers, such as vinyl acetate and vinyl propionate. These other structural units may be contained in one or more types, and the content thereof in the copolymer (D) is preferably 40 mol % or less, more preferably 20 mol % or less, relative to 100 mol % of the total amount of the structural units represented by formula (1) and formula (2).

[0030] Copolymer (D) can be produced by a known production method. For example, it can be produced by polymerizing a monomer mixture containing 2-(meth)acryloyloxyethyl phosphorylcholine and alkyl (meth)acrylate, and, if necessary, monomers corresponding to the other structural units, in the presence of a radical polymerization initiator under an inert gas atmosphere such as nitrogen, by a known method such as solution polymerization. The content ratio of each monomer in this case may be set to a ratio corresponding to the desired content ratio of each structural unit in copolymer (D).

[0031] The cosmetic composition of the present invention may contain one copolymer selected from the above-mentioned copolymer (D), either singly or in combination of two or more. The copolymer (D) may be one produced by the polymerization method described above, but commercially available products such as "Lipidure (registered trademark)-PMB (Ph10)" (polyquaternium-51), "Lipidure (registered trademark)-S," and "Lipidure (registered trademark)-NR" (polyquaternium-61) (all manufactured by NOF Corporation) may also be used.

[0032] The content of copolymer (D) in the cosmetic composition of the present invention is 0.01 to 10% by mass, preferably 0.1 to 7% by mass, and more preferably 0.5 to 5% by mass, based on the total amount of the cosmetic composition. If the content of copolymer (D) is too low, it may be difficult to obtain the effect of stabilizing the oil-soluble active ingredient (B) during high-temperature storage, or the external color of the cosmetic composition may change. Furthermore, the external transparency of an aqueous solution prepared from this composition may decrease. If the content of copolymer (D) is too high, the feeling during use may be reduced.

[0033] The mass ratio (B / D) of the content of the oil-soluble active ingredient (B) to the content of the copolymer (D) is 0.01 to 5, preferably 0.05 to 3, more preferably 0.1 to 1, and particularly preferably 0.10 to 0.7. If the mass ratio (B / D) is too small, the amount of the oil-soluble active ingredient (B) relative to the copolymer (D) is too small, making it difficult to obtain the functions of the oil-soluble active ingredient (B). If the mass ratio (B / D) is too large, the amount of the copolymer (D) relative to the oil-soluble active ingredient (B) is too small, making it difficult to stabilize the oil-soluble active ingredient (B).

[0034] [Cosmetic composition] The cosmetic composition of the present invention contains at least the above-mentioned component (A), oil-soluble active ingredient (B), component (C), and copolymer (D), and is in a form in which the oil-soluble active ingredient (B) and copolymer (D) form associations to form oil droplets, which are dispersed in component (A), which is a solvent. The oil droplets formed by the association of the oil-soluble active ingredient (B) and the copolymer (D) preferably have a particle size (D50) of 500 nm or less, more preferably 300 nm or less, and even more preferably 200 nm or less, based on the volume of the 50% cumulative particle size distribution. Furthermore, the ratio D90 / D10 of the particle size (D10) of the 10% cumulative particle size distribution to the particle size (D90) of the 90% cumulative particle size distribution based on the volume of the oil droplets is preferably 10 or less, more preferably 7 or less, and even more preferably 5 or less. If the particle size (D50) or the ratio D90 / D10 is too large, the oil droplets may easily aggregate, resulting in a decrease in uniformity, and the transparency and usability of the aqueous solution prepared from this composition may be reduced. Furthermore, the stabilization effect of the oil-soluble active ingredient (B) may be insufficient. The particle size distribution of oil droplets consisting of an association of the oil-soluble active ingredient (B) and the copolymer (D) can be measured using a commercially available particle size distribution analyzer, etc. Known methods for measuring particle size distribution include electron microscopy, atomic force microscopy, static light scattering, laser diffraction, dynamic light scattering, centrifugal sedimentation, electric pulse measurement, chromatography, and ultrasonic attenuation, and devices corresponding to each principle are commercially available. In order to measure the particle size distribution of primary particles of oil droplets, it is desirable to dilute the cosmetic composition with water to an appropriate concentration and then perform the measurement.

[0035] (Other ingredients) The cosmetic composition of the present invention is prepared using the above-mentioned components (A) to (D) as essential components. In addition to these essential components, other components that are generally incorporated into ordinary cosmetics can also be incorporated depending on the purpose, as long as they do not impair the effects of the present invention. Examples of such other ingredients include water, moisturizers, thickeners, plant extracts, colorants, antioxidants (excluding ingredient (C)), pH adjusters, preservatives, and chelating agents. Of the other components, the content of water is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less, relative to the total amount of the cosmetic composition. The total content of component (A), oil-soluble active ingredient (B), component (C) and copolymer (D) is preferably 90% by mass or more, more preferably 95% by mass or more, and even more preferably 97% by mass or more, based on the total amount of the cosmetic composition.

[0036] (Method for preparing a cosmetic composition) The method for preparing the cosmetic composition of the present invention is not particularly limited, and in addition to conventional emulsifying devices such as stirrers, impeller agitators, and homomixers, high-pressure emulsifying devices such as Manton-Gaulin high-pressure homogenizers, water jet reversal high-pressure emulsifiers, microfluidizers, nanomizers, starbursts, and wet atomizers can also be used, and the required particle size can be obtained using one of these alone or in combination of two or more. From the perspective of reducing the particle size of the oil-soluble active ingredient (B), the use of a high-pressure emulsifier is preferred. For example, a cosmetic composition can be obtained by placing components (A) to (D) and other components in a container and emulsifying them in the above-mentioned standard emulsifying device at 500 to 10,000 rpm for 5 to 30 minutes at a temperature of 20 to 80° C. Alternatively, a cosmetic composition in which the oil-soluble active ingredient (B) has a smaller particle size can be obtained by performing high-pressure emulsification treatment any number of times using the above-mentioned high-pressure emulsifying machine at a temperature of 20 to 60° C. and a pressure of 10 to 250 MPa. [Example]

[0037] EXAMPLES The present invention will be specifically explained below with reference to examples and comparative examples, but the present invention is not limited to these examples in any way.

[0038] (Measurement of weight average molecular weight of polymer) The weight average molecular weight of the polymer was measured under the following GPC (gel permeation chromatography) conditions. Preparation of measurement solution The sample polymer was dissolved in a mixed solvent of chloroform / methanol (=6 / 4, volume ratio) containing 0.5% by mass of lithium bromide to prepare a 0.5% by mass solution. ·GPC analysis conditions Column: PL gel 5 μm MIXED-C, two columns in series (Polymer Laboratory), elution solvent: chloroform / methanol (6 / 4, volume ratio) mixed solvent containing 0.5% by mass of lithium bromide, detection: parallax refractometer, standard substance for weight-average molecular weight (Mw): PMMA (Polymer Laboratory), flow rate: 1.0 mL / min, amount of sample solution used: 20 μL, column temperature: 40°C, and molecular weight calculation program built into the Tosoh integrator (GPC program for SC-8020) was used.

[0039] (Synthesis of Polymer 1) Synthesis Example 1 3.57 g of MPC (2-methacryloyloxyethyl phosphorylcholine) and 16.43 g of octadecyl methacrylate (C18MA) (monomer composition molar ratio, MPC / C18MA = 30 / 70) were dissolved in 180 g of n-butanol and placed in a four-necked flask. After blowing nitrogen into the solution for 30 minutes, 0.82 g of azobisisobutyronitrile was added at 60°C and the mixture was polymerized for 8 hours. The polymerization solution was added dropwise to 3 liters of acetone while stirring, and the resulting precipitate was filtered and dried in vacuum at room temperature for 48 hours to obtain 15.8 g of powder. The resulting copolymer had a weight-average molecular weight of 326,000. This was designated Polymer 1. In addition, MPC is R in Equation (1). 1 is a methyl group, and C18MA is R 2 is a methyl group, m is 17, and the ratio of the content of C18MA structural units to MPC (l / k) is 7 / 3.

[0040] (Synthesis of Polymer 2 to Polymer 4) Synthesis Examples 2-4 In accordance with the synthesis of polymer 1 in Synthesis Example 1, the ratios (l / k) of the monomer and structural unit contents were adjusted to those shown in Table 1, and polymers 2 to 4 were obtained by the same procedure as in Synthesis Example 1. The weight average molecular weights of the obtained copolymers are shown in Table 1. The monomer of formula (2) used in the synthesis of polymer 3 was ethyl methacrylate, and in formula (2), R 2 is a methyl group and m is 1. Polymer 4 is a homopolymer of C18MA.

[0041] [Table 1]

[0042] (Preparation of cosmetic composition) Example 1 The raw materials were blended to obtain the composition of Example 1 in Table 2, and 100 g of a cosmetic composition was prepared. That is, the raw materials of Example 1 were placed in a container and pre-emulsified at room temperature using a tabletop homomixer (manufactured by Mizuho Kogyo Co., Ltd.). This was then treated twice at room temperature using a Systemizer (manufactured by Mutual Corporation, C17) at a pressure of 180 MPa, thereby obtaining a cosmetic composition.

[0043] Examples 2 to 7, Comparative Examples 1 to 6 It was prepared in the same manner as in Example 1.

[0044] Example 8 The raw materials of Example 8 were placed in a container and mixed at room temperature using a tabletop homomixer (manufactured by Mizuho Kogyo Co., Ltd.) to obtain a cosmetic composition.

[0045] The cosmetic compositions obtained in the above Examples and Comparative Examples were subjected to particle size distribution measurement as described below, and further to the following evaluations. In addition, each panelist conducting the evaluations was trained in a preliminary evaluation test conducted prior to the evaluation test so that the level of evaluation corresponding to each score would be roughly the same, and this ensured that there would be no differences in evaluation criteria between panelists.

[0046] (Evaluation of the residual rate of oil-soluble active ingredients in cosmetic compositions when stored at high temperatures) 10 g of the cosmetic composition was stored in a screw tube shielded from light with aluminum foil and stored in an incubator (Yamato Scientific, IS900) at 40°C. One month after storage, the composition was removed and the amount of oil-soluble active ingredient was measured using HPLC (Hitachi High-Tech, LaChrom Elite). Details of the quantitative measurement conditions are described below. Preparation of measurement solution The cosmetic composition was diluted 100 times with ion-exchanged water, and the diluted solution was diluted 10 times with the mobile phase and filtered through a 0.45 μm PTFE filter to prepare a measurement solution. Measurement conditions Column: Wakopak Wakosil-2 5C18 HG 4.6 mm × 150 mm (Fujifilm Wako Pure Chemical Industries, Ltd.), column temperature: 35°C, mobile phase: methanol / acetonitrile (=1 / 1, volume ratio), flow rate: 0.7 mL / min, injection volume: 10 μL, detection: 325 nm The amount of oil-soluble active ingredient relative to the amount before the start of storage was taken as the residual rate of the oil-soluble active ingredient, and the residual rate was evaluated as follows: The residual rate was rounded to the nearest integer. ◎: The survival rate was 95% or more. ○: The residual rate was 80% or more and less than 95%. △: The residual rate was 60% or more but less than 80%. ×: The remaining rate was less than 60%.

[0047] (Change in the appearance color of oil-soluble active ingredients during high-temperature storage of cosmetic compositions) Two tubes containing 10 g of the cosmetic composition in colorless, transparent glass screw tubes shielded from light by aluminum foil were prepared and stored for one month at 40°C and 5°C, respectively. After one month, the 40°C stored sample was visually inspected for discoloration (yellowing or browning) in a screw tube with the 5°C stored sample as a control, and the degree of discoloration was evaluated as follows: ◎: No discoloration was observed. ○: Almost no discoloration was observed. ×: Discoloration was observed.

[0048] (Evaluation of the feel of a 1% aqueous solution of the cosmetic composition) 1 g of the cosmetic composition and 99 g of purified water were placed in a container and stirred to prepare a 1% by mass aqueous solution of the cosmetic composition. 20 female panelists spread the resulting aqueous solution (approximately 1 g) over their entire faces, and the stickiness after use was evaluated as follows: 2 points: If there is no squeaking and it feels fresh after use. 1 point: If there is less creaking and a slight feeling of freshness after use. 0 points: If there was a creaking sound after use and it did not feel fresh. The total scores of the 20 people were calculated and evaluated according to the following criteria, and are shown in the table. ◎: The total score is 35 points or more, and no panelists gave a score of 0. ○: The total score is between 30 and 35 points, or the total score is 35 or more points but there is a panelist who gave a score of 0. △: The total score is between 20 and 30 points. ×: The total score is less than 20 points.

[0049] (Transmittance evaluation of 0.1% aqueous solution of cosmetic composition) 0.1 g of the cosmetic composition and 99.9 g of purified water were placed in a container and stirred to prepare a 0.1% by mass aqueous solution of the cosmetic composition. The transmittance of the resulting aqueous solution was measured (600 nm, T%) and evaluated according to the following criteria. The transmittance was measured using a UV-visible spectrophotometer (Hitachi, U-3010). ⊚: The transmittance was 75% or more. ◯: The transmittance was 50% or more and less than 75%. △: The transmittance was 25% or more and less than 50%. ×: The transmittance was less than 25%.

[0050] (Evaluation of particle size of 0.1% aqueous solution of cosmetic composition) 0.1 g of the cosmetic composition and 99.9 g of purified water were placed in a container and stirred to prepare a 0.1% by mass aqueous solution of the cosmetic composition. The particle size distribution of the resulting aqueous solution was measured. A particle size / molecular weight measuring system (ELSZ-2000, manufactured by Otsuka Electronics Co., Ltd.) was used to measure the particle size distribution. Tables 2 and 3 show the particle size of the 10% volume-based cumulative particle size distribution (D10), the particle size of the 50% volume-based cumulative particle size distribution (D50), and the particle size of the 90% volume-based cumulative particle size distribution (D90), as well as the ratio D90 / D10.

[0051] [Table 2]

[0052] [Table 3]

[0053] *1: BASF Retinol 15D (a 15:85 solution of retinol and caprylic / capric triglyceride) *2: Fujifilm Wako Pure Chemical Industries, Ltd., Polyoxyethylene (20) sorbitan monooleate

[0054] The cosmetic compositions of Examples 1 to 8 improved the stability of the oil-soluble active ingredient retinol during high-temperature storage, maintained the quality of retinol, and the aqueous solutions prepared from these compositions had high transparency, were non-sticky after use, and had a good feel during use. Furthermore, changes in the appearance of the compositions during high-temperature storage were suppressed.

[0055] On the other hand, as for the cosmetic compositions of Comparative Examples 1 to 6, which do not satisfy any of the essential requirements of the present invention, no sufficient effectiveness was observed in any of the evaluation items, as described below. The cosmetic composition of Comparative Example 1, which did not contain component (C), was evaluated as having insufficient stability of retinol during high-temperature storage. The cosmetic composition of Comparative Example 2, which did not contain component (C) but contained glutathione instead, was evaluated as having insufficient stability of retinol during high-temperature storage and insufficient suppression of change in appearance color. The cosmetic composition of Comparative Example 3, in which m of the compound of formula (2), which is a structural unit of copolymer (D), is too small, was evaluated as having insufficient non-stickiness in the aqueous solution prepared from this composition. The cosmetic composition of Comparative Example 4, in which the copolymer (D) did not contain the structural unit of formula (1), was evaluated as having insufficient non-stickiness and transparency in appearance of an aqueous solution prepared from this composition. The cosmetic composition of Comparative Example 5, which did not contain copolymer (D), was evaluated as having insufficient non-stickiness of the aqueous solution prepared from this composition. The cosmetic composition of Comparative Example 6, in which the mass ratio (B / D) of the oil-soluble active ingredient (B) to the copolymer (D) was too large, was evaluated as being insufficient in terms of the stability of retinol during high-temperature storage and the suppression of change in appearance color, as well as the non-stickiness and appearance transparency of an aqueous solution prepared from this composition. [Industrial Applicability]

[0056] The cosmetic composition of the present invention can maintain the quality of oil-soluble active ingredients for achieving cosmetic effects such as whitening and anti-wrinkle, and can therefore be suitably used in lotions, massage creams, facial cleansing creams, packs, etc.

Claims

[Claim 1] A cosmetic composition comprising the following components (A) to (D), wherein the mass ratio (B / D) of the content of component (B) to the content of component (D) is 0.01 to 5: (A) 40 to 99% by mass of a polyhydric alcohol having 3 to 6 carbon atoms and a valence of 2 to 3 (B) 0.001 to 30% by mass of an oil-soluble active ingredient (C) 0.001 to 5% by mass of ascorbate and / or polyphenol (D) 0.01 to 10% by mass of a copolymer having a constitutional unit represented by the following formula (1) and a constitutional unit represented by the following formula (2): 【Chemical 1】 (In the formula, R １ represents a hydrogen atom or a methyl group.) 【Chemistry 2】 (In the formula, R ２ represents a hydrogen atom or a methyl group, and m represents an integer of 3 to 21.

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