Cosmetics designed to target rough or irritated areas of the skin.

Abstract

We provide cosmetics designed to act intensively on areas of skin that are irritated or damaged. [Solution] A cosmetic product for which the product is intended to act intensively on rough areas of the skin, Anionic polymers, and water It includes, The anionic polymer has at least one load electroactive group selected from the group consisting of sulfate groups, sulfate groups, sulfonic acid groups, sulfonate groups, phosphate groups, phosphonic acid groups, phosphonate groups, carboxyl groups, and carboxylate groups, or a salt thereof. A cosmetic composition having a pH of 5.5 or less.

Description

Technical Field

[0001] The present invention relates to a cosmetic for intensively acting on rough parts of the skin.

Background Art

[0002] With the changes in the environment and the diversification of eating habits, the deterioration of skin conditions such as sensitive skin and atopic dermatitis has become more serious. Various methods can be considered as ways to improve these conditions. One such method is to attempt improvement by applying a composition having an effect of improving such skin conditions. As such compositions, various products such as cosmetics having a moisturizing effect or an effect of improving rough skin have been developed.

[0003] For example, in Patent Document 1, a skin external preparation is disclosed which is characterized by containing at least one or more mucopolysaccharides with reduced stickiness and a polymer of 2-methacryloyloxyethyl phosphorylcholine. Mucopolysaccharides such as hyaluronic acid and chondroitin sulfate have been used as moisturizing agents in the skin, similar to polyhydric alcohols such as sorbitol, ethylene glycol, and glycerin, organic acid salts such as sodium pyrrolidone carboxylate and sodium lactate, and proteins such as collagen and elastin. <00​​​​​For example, Patent Document 2 discloses a cosmetic and / or dermatological composition containing an acidic aqueous medium acceptable as a cosmetic and at least one cross-linked poly(2-acrylamide-2-methylpropanesulfonic acid) polymer that is at least 90% neutralized. Examples of organic active substances that can be included in such an acidic aqueous medium include kojic acid, caffeic acid, salicylic acid and its derivatives. These components are generally used in the treatment of blemishes.

[0006] Thus, much research has been conducted on compositions that have the effect of improving skin condition. However, for example, when the deterioration of skin condition occurs unevenly, relatively more care is required to improve areas that are more severely deteriorated, while relatively less care is sufficient to improve areas that are less severely deteriorated. However, there are problems in that the areas to which topical compositions are applied are usually treated uniformly, and appropriate care according to the degree of deterioration is not provided. In such cases, the effect is not always sufficient. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 9-052848 [Patent Document 2] Japanese Patent Application Publication No. 10-067616 [Overview of the Initiative]

[0008] The inventors have discovered that a composition comprising a specific polymer having a specific pH range has the excellent effect of being able to act intensively on rough areas of the skin. This invention is based on this finding.

[0009] The present invention provides the following: (1) A cosmetic product intended to act intensively on rough areas of the skin, Anionic polymers, and water It includes, The anionic polymer has at least one load electroactive group selected from the group consisting of sulfate groups, sulfate groups, sulfonic acid groups, sulfonate groups, phosphate groups, phosphonic acid groups, phosphonate groups, carboxyl groups, and carboxylate groups, or a salt thereof. A cosmetic composition having a pH of 5.5 or less. (2) The cosmetic composition according to (1), wherein the load electroactive group is a sulfate group or a sulfonic acid group. (3) The cosmetic composition according to (1) or (2), wherein the anionic polymer is selected from the group consisting of acrylic polymers, urethane polymers, silicone polymers, and polysaccharides or their derivatives. (4) The cosmetic composition according to any one of (1) to (3), wherein the anionic polymer is selected from the group consisting of (hydroxyethyl acrylate / sodium acryloyldimethyltaurate) copolymer, (sodium acrylate / sodium acryloyldimethyltaurate) copolymer, (acrylamide / sodium acryloyldimethyltaurate) copolymer, (ammonium acryloyldimethyltaurate / beheneth-25 methacrylate) crosspolymer, (ammonium acryloyldimethyltaurate / vinylpyrrolidone) copolymer, (sodium acryloyldimethyltaurate / dimethylacrylamide) crosspolymer, and sulfated polysaccharides. (5) The anionic polymer is the following repeating unit: [ka] (In the formula, R 1 is hydrogen or methyl, R 2 C 1-10 It is a hydrocarbon group, X is the aforementioned load electrochemical group or a salt thereof. A cosmetic composition comprising any of (1) to (4). (6) The cosmetic composition according to any one of (1) to (5), wherein the anionic polymer is in the form of polymer particles. The cosmetic according to any one of (1) to (6), wherein the anionic polymer selectively adheres to rough parts of the skin. (8) The cosmetic according to any one of (1) to (7) for improving the texture, touch, or appearance of the skin. (9) An anionic polymer, and water Use for intensively acting on rough parts of the skin of a cosmetic comprising, wherein the anionic polymer has at least one negatively charged group selected from the group consisting of a sulfate group, a sulfate group, a sulfonic acid group, a sulfonate group, a phosphate group, a phosphate group, a phosphonic acid group, a phosphonate group, a carboxyl group, and a carboxylate group, or a salt thereof, the use wherein the pH of the cosmetic is 5.5 or less. [[ID= 14]]

[0010] By using the cosmetic of the present invention, it is possible to intensively act on rough parts of the skin.

Brief Description of the Drawings

[0011] [Figure 1] Figure 1 is a graph showing the comparison results of the surface potentials of rough parts and normal parts of the skin. [Figure 2] Figure 2 is an image obtained by photographing an application site using a near-infrared camera system before and after applying the cosmetic of the present invention and a cosmetic that is not the cosmetic of the present invention to rough skin. [Figure 3] Figure 3 is an image obtained by observing through transmission light and fluorescence how a (acryloyldimethyltaurine ammonium / methacrylic acid behenes-25) cross-polymer adheres to each of rough parts and non-rough parts of the skin. [Figure 4] Figure 4 is an image obtained by photographing an application site using a fluorescence video microscope after applying an aqueous solution containing a (dimethylacrylamide / sodium acryloyldimethyltaurine) cross-polymer and polyquaternium-10 and an aqueous solution not containing these to normal skin and rough skin. [Figure 5]Figure 5 is an image obtained by photographing the application site using a video microscope after applying the cosmetic of the present invention and a cosmetic that is not the cosmetic of the present invention to rough skin. Detailed Description of the Invention

[0012] According to one embodiment of the present invention, there is provided a cosmetic for intensively acting on rough portions of the skin. This cosmetic comprises an anionic polymer and water, and its pH is 5.5 or less. The anionic polymer contained in this cosmetic has at least one negatively charged group selected from the group consisting of a sulfate group, a sulfonate group, a sulfonic acid group, a sulfonate group, a phosphate group, a phosphonate group, a phosphonic acid group, a carboxyl group, and a carboxylate group, or a salt thereof. The cosmetic of the present invention is not particularly limited, but by applying it to the skin, it is possible to intensively act on the rough portions thereof.

[0013] The anionic polymer in the present invention has at least one negatively charged group selected from the group consisting of a sulfate group, a sulfonate group, a sulfonic acid group, a sulfonate group, a phosphate group, a phosphonate group, a phosphonic acid group, a carboxyl group, and a carboxylate group, or a salt thereof. Examples of the salt include an ammonium salt, an alkali metal, or an alkaline earth metal salt, preferably an ammonium salt or an alkali metal salt, and more preferably an ammonium salt or a sodium salt. According to one preferred embodiment of the present invention, the anionic polymer in the present invention has a sulfate group, a sulfonic acid group, or a salt thereof, preferably a sulfate group, a sulfonic acid group, or an ammonium salt or sodium salt thereof.

[0014] The anionic polymer in the present invention may be a homopolymer or a copolymer. The copolymer in the present invention may be a copolymer obtained from two types of monomers, or may be obtained from more than two types of monomers, for example, a terpolymer obtained from three types of monomers.

[0015] The anionic polymer in this invention may be natural or artificially synthesized.

[0016] In the present invention, one type of anionic polymer may be used alone, or two or more different types of anionic polymers may be used in combination.

[0017] The content of the anionic polymer in the present invention relative to the total amount of the cosmetic is preferably 0.01 to 3% by mass.

[0018] The form of the anionic polymer in the present invention is not particularly limited, but is preferably polymer particles. A microgel may be formed using a suitable solvent such as water and other necessary raw materials (e.g., cationic polymers). A microgel refers to a polymer particle gel with a diameter of several μm to several hundred μm. Its shape is not particularly limited, but may be spherical or have a fixed shape, or it may be amorphous.

[0019] In the present invention, the microgel preferably has a negative total charge. In the present invention, "negative total charge" of the microgel means that the total charge obtained by summing the charges of all the microgel particles contained in the cosmetic is negative. The method for making the total charge negative is not particularly limited, but for example, it may be done by incorporating only anionic polymers, or by incorporating anionic polymers and cationic polymers in a ratio range in which the anionic polymer is more abundant than the ratio of the two polymers that neutralizes the charge and produces the most aggregates.

[0020] The average particle size of the microgel in the water-swollen state in this invention is preferably 2 to 50 μm. The average particle size of the "microgel" in the water-swollen state in this invention refers to the particle size at 50% of the cumulative value in the particle size distribution, and is the value measured using an aqueous solution containing 0.05 mass% NaCl as the solvent. This measurement can be performed by a laser analysis particle size analyzer, or other known methods (e.g., measurement by microscopic observation image analysis) may be used. In such measurements, if the shape of the microgel is spherical, its diameter (outer diameter) may be used as the particle size, and if the shape of the microgel is irregular or other than spherical, the longest part of that shape may be used as the particle size.

[0021] The shape of the anionic polymer in this invention is not particularly limited, but may take a fixed shape such as spherical, fragmentary, plate-like, flaky, or needle-like, or it may be amorphous. The average particle size of the anionic polymer in the water-swelled state in this invention is not particularly limited, but when formed into a microgel with a cationic polymer, it may be less than 2 μm.

[0022] According to one preferred embodiment of the present invention, the anionic polymer in the present invention is selected from the group consisting of acrylic polymers, urethane polymers, silicone polymers, and polysaccharides or their derivatives, and is preferably selected from acrylic polymers, polysaccharides, or their derivatives.

[0023] According to one more preferred embodiment of the present invention, the anionic polymer in the present invention is selected from acrylic polymers or derivatives thereof having at least one load-electric group selected from the group consisting of sulfate groups, sulfate groups, sulfonic acid groups, and sulfonate groups, or a salt thereof. Specific examples of such acrylic polymers or derivatives include (hydroxyethyl acrylate / sodium acryloyldimethyltaurate) copolymer, (sodium acrylate / sodium acryloyldimethyltaurate) copolymer, (acrylamide / sodium acryloyldimethyltaurate) copolymer, (ammonium acryloyldimethyltaurate / beheneth-25 methacrylate) crosspolymer, (ammonium acryloyldimethyltaurate / vinylpyrrolidone) copolymer, and (sodium acryloyldimethyltaurate / dimethylacrylamide) crosspolymer.

[0024] According to another more preferred embodiment of the present invention, the anionic polymer in the present invention is selected from acrylic polymers or derivatives thereof having at least one load-electric group selected from the group consisting of phosphate groups, phosphate groups, phosphonic acid groups, and phosphonate groups, or a salt thereof. Specific examples of such acrylic polymers or derivatives include (acrylic acid / phosphorylcholine acrylic acid glycol) crosspolymers.

[0025] According to another more preferred embodiment of the present invention, the anionic polymer in the present invention is selected from acrylic polymers or derivatives thereof having at least one load-electrostatic group selected from the group consisting of carboxyl groups and carboxylate groups, or a salt thereof. Specific examples of such acrylic polymers or derivatives include sodium polyacrylate, carbomer, sodium acrylate graft starch, (acrylates / alkyl acrylate (C10-30)) crosspolymer, and the like.

[0026] According to another more preferred embodiment of the present invention, the anionic polymer in the present invention is selected from polysaccharides or derivatives thereof, and such polysaccharides or derivatives are preferably sulfated polysaccharides, specifically, heparin, chondroitin sulfate, carrageenan, fucoidan, rhamnan, sacran, and the like, but are not limited thereto.

[0027] According to another preferred embodiment of the present invention, the anionic polymer in the present invention comprises the following repeating units: [ka] (In the formula, R 1 is hydrogen or methyl, preferably hydrogen. R 2 C 1-10 It is a hydrocarbon group, preferably C 3-5 It is an alkylene group, X is the aforementioned electrostatic load group or a salt thereof, preferably a sulfate group, a sulfonic acid group, or an ammonium salt or alkali metal salt thereof, and more preferably an alkali metal salt or ammonium salt of sulfonic acid. It consists of including. Examples of the above anionic polymers include (hydroxyethyl acrylate / sodium acryloyldimethyltaurate) copolymer, (sodium acrylate / sodium acryloyldimethyltaurate) copolymer, (acrylamide / sodium acryloyldimethyltaurate) copolymer, (ammonium acryloyldimethyltaurate / beheneth-25 methacrylate) crosspolymer, (ammonium acryloyldimethyltaurate / vinylpyrrolidone) copolymer, (sodium acryloyldimethyltaurate / dimethylacrylamide) crosspolymer, and preferably (ammonium acryloyldimethyltaurate / beheneth-25 methacrylate) crosspolymer, (ammonium acryloyldimethyltaurate / vinylpyrrolidone) copolymer, and (sodium acryloyldimethyltaurate / dimethylacrylamide) crosspolymer.

[0028] The cosmetic composition in the present invention may further contain a cationic polymer. The form of the cationic polymer in the present invention is not particularly limited and may be polymer particles, or it may be a "microgel" using a suitable solvent such as water or other necessary raw materials (e.g., anionic polymer). The cationic polymer in the present invention is not particularly limited, but examples include cationized hydroxyalkylcellulose (e.g., O-[2-hydroxy-3-(trimethylammonio)propyl]hydroxyethylcellulose chloride (polyquaternium-10), etc.), cationized cellulose, cationized guar gum, cationized locust bean gum, cationized chitosan, cationized oligosaccharide, cationized starch derivative, acrylamide-acrylic acid-dimethyldiallylammonium chloride copolymer, and vinylpyrrolidone-N,N-dimethylaminoethyl methacrylic acid copolymer sulfuric acid solution.

[0029] The content of the cationic polymer in the present invention relative to the total amount of the cosmetic is preferably 0.001 to 1.5% by mass.

[0030] The cosmetic composition in the present invention may further contain an amphoteric polymer. The form of the amphoteric polymer in the present invention is not particularly limited and may be polymer particles, or it may be a "microgel" using a suitable solvent such as water or other necessary raw materials (e.g., anionic polymer). The amphoteric polymer in the present invention is not particularly limited, but examples include polyquaternium-51 (a copolymer of 2-methacryloyloxyethyl phosphorylcholine and butyl methacrylate), polyquaternium-39 (a copolymer of acrylamide, acrylic acid, and dimethyldiallylammonium chloride), polyquaternium-47 (a copolymer of acrylic acid, methyl acrylate, and methacrylamidopropyltrimethylammonium chloride), polyquaternium-53 (a copolymer of acrylic acid, acrylamide, and methacrylamidopropyltrimonium chloride), and derivatives thereof.

[0031] The content of the amphoteric polymer in the present invention, relative to the total amount of the cosmetic composition, is preferably 0.001 to 1.5% by mass.

[0032] The cosmetic composition of the present invention may further contain a polyhydric alcohol. Such a polyhydric alcohol is not limited to any alcohol having two or more hydroxyl groups in the same molecule, but examples include glycerin, diglycerin, polyglycerin, 1,3-butylene glycol, ethylene glycol, propylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polyethylene glycol-polypropylene glycol, trimethylolethane, trimethylolpropane, erythritol, pentaerythritol, sorbitan, glucose, sorbitol, maltitol, sucrose, raffinose, hexylene glycol, 1,2-pentanediol, trehalose, and the like.

[0033] According to one preferred embodiment of the present invention, the cosmetic composition of the present invention comprises one or more polyhydric alcohols selected from the group consisting of glycerin and polyglycene, and preferably further comprises one or more dihydric alcohols selected from the group consisting of 3 to 6 carbon atoms.

[0034] The content of polyhydric alcohol in the present invention relative to the total amount of cosmetic composition is preferably 1 to 30% by mass.

[0035] The pH of the cosmetic composition of the present invention is not particularly limited as long as it is 5.5 or less, but is preferably 4.0 to 5.2, and more preferably 4.1 to 5.0.

[0036] The method for adjusting the pH of the cosmetic composition of the present invention can be any general method, and the ingredients are not limited to those listed above. However, inorganic and organic alkaline and acidic components, which are also used as neutralizing agents and buffering agents, can be used. Such components can be added to the cosmetic composition of the present invention in appropriate amounts. In the present invention, appropriate amounts refer to the amount that a person skilled in the art would normally use when preparing a desired cosmetic composition, and are not particularly limited.

[0037] The cosmetic composition of the present invention may further contain other known components (additives) used in cosmetics. Such components, though not limited to, include emulsifiers, wettable powders, solvents, emollients, stabilizers, thickeners, preservatives, lubricants, chelating agents, fillers, excipients, powders, fragrances, scents, absorbents, dyes, opacifiers, antioxidants, vitamins, amino acids, neutralizing agents, buffering agents, and the like.

[0038] The cosmetic composition of the present invention may be a liquid, semi-solid, or solid, and can take the form of, for example, a solution, suspension, dispersion, emulsion, cream, ointment, gel, lotion, foam, paste, or spray.

[0039] The cosmetic composition of the present invention is used to act intensively on rough areas of the skin. In the present invention, rough areas of the skin refer to areas where there is a decrease in stratum corneum moisture content, keratinization disorders, uneven texture, decreased surface smoothness (scaling), increased transepidermal water loss, etc. By applying the cosmetic composition of the present invention to the skin and acting intensively on these rough areas, the rough areas of the skin can return to or approach the state of healthy skin, and the skin as a whole can effectively and efficiently return to or approach the state of normal skin.

[0040] According to one more preferred embodiment of the present invention, the cosmetic composition of the present invention is used to enhance the improvement of rough areas of skin. By using the cosmetic composition of the present invention, it is also possible to effectively and efficiently improve rough areas of skin, which includes shortening the time it takes for the skin to return to or approach the condition of healthy skin or normal skin after applying the cosmetic composition of the present invention to the subject.

[0041] In the present invention, the concentrated action on rough skin is not particularly limited, but may be achieved by the anionic polymer contained in the cosmetic composition of the present invention selectively adhering to the rough skin.

[0042] When skin deterioration occurs unevenly, areas with greater deterioration require relatively more care to improve, while areas with less deterioration require relatively less care. Generally, it is known that the surface potential of rough areas of skin is relatively higher than that of normal areas. Although not bound by theory, the negatively charged anionic polymer contained in the cosmetic of this invention, when applied as a cosmetic within a specific pH range, tends to adhere to rough areas of skin with relatively high surface potentials. This makes it possible to concentrate the action on rough areas of skin.

[0043] The cosmetic composition of the present invention may further be used to improve the texture, feel, or appearance of the skin. [Examples]

[0044] The present invention will be specifically described based on the following examples, but the present invention is not limited to these examples. Unless otherwise specified, the content is expressed in mass percent.

[0045] Comparative evaluation of surface potential between irritated and normal skin areas. By measuring the surface potential of the stratum corneum, the surface potentials of irritated and normal areas of skin were compared and evaluated. First, the outermost layer of stratum corneum was collected from a non-irritated area of ​​the abdomen, cleaned with cotton impregnated with a water / ethanol = 1:1 solution, using stratum corneum tape (stratum corneum checker D-Squame, D-100) (Clinical & Derm) to ensure no adhesive residue remained (referred to as "untreated"). Subsequently, the stratum corneum was peeled off five times using the stratum corneum tape, and the seventh layer was collected in the same manner (referred to as "after tape stripping"). The surface potentials of both were measured using a solid surface zeta potential analyzer (SurPASS 3, AntonPaar) while adjusting the pH with potassium hydroxide and hydrochloric acid. The results are shown in Figure 1.

[0046] Compared to untreated stratum corneum, the surface potential of the lower layer of stratum corneum after tape stripping was generally shifted to the positive side when measured at different pH levels, and the isoelectric point was also higher at approximately 5.2 compared to approximately 4.8. This suggests that the potential is higher in the undifferentiated stratum corneum cell regions.

[0047] Evaluation of the effects on irritated skin. Cosmetics for Example 1 and Comparative Example 1 were prepared by conventional methods using the formulations shown in Table 1.

[0048] [Table 1]

[0049] The effects of the prepared cosmetic formulations of Example 1 and Comparative Example 1 on areas of skin irritation were evaluated. The evaluation was conducted in accordance with the content described in Non-Patent Literature (MEDICAL IMAGING TECHNOLOGY Vol.30 No.1 January 2012). In detail, first, a 10% SDS aqueous solution was applied to the forearm of a 48-year-old female subject for 1 hour to induce skin irritation on the forearm. A near-infrared camera system (Shiseido) equipped with a 1950 nm optical filter was used to photograph a 2 cm × 2 cm area including the area where skin irritation occurred (Figure 2). The mean value and standard deviation of the reflectance intensity (hereinafter referred to as "luminance") of the image in the photographed area were calculated. The photographed area was defined as the area where the area of ​​skin irritation and the area of ​​normal skin were in a 1:1 area ratio. Next, the cosmetic formulation of Example 1 or Comparative Example 1 was applied to the same area where luminance was measured in the same subject. After 5 minutes, the applied area was washed with water and left for 30 minutes. Subsequently, images were taken of the areas where the cosmetic was applied using the same method as described above (Figure 2), and the average value and standard deviation of brightness were calculated. Low brightness indicates the presence of many OH groups, and therefore, areas with low brightness indicate areas with high moisture content. A low standard deviation suggests high uniformity. The measurements were performed under conditions of a temperature of 22±1℃ and a humidity of 50±5%. The results are shown in Table 2 below.

[0050] [Table 2]

[0051] Table 2 shows that when the cosmetic composition of Comparative Example 1 was used, the average brightness remained almost unchanged, while when the cosmetic composition of Example 1 was used, the average brightness decreased significantly. The rate of change in standard deviation also decreased significantly in Example 1 compared to cosmetic composition 1. Comparative Example 1 is an aqueous solution of polyhydric alcohol, which is generally known as a moisturizing ingredient in cosmetics, but the rate of change in brightness suggests that it is unlikely to remain on the skin after washing with water at this application time. On the other hand, when the cosmetic composition of Example 1 was applied, it was suggested that the overall moisture content increased even after washing, and that the effect of increasing moisture content was even greater in areas with low moisture content.

[0052] Evaluation of selective adhesion to the incompletely keratinized stratum corneum. The components shown in Table 3 were mixed to prepare the composition of Reference Example 1. Prior to this, a solution of fluorescently labeled polymer A was prepared. (Acryloyldimethyltaurate ammonium / methacrylate beheneth-25) crosspolymer was dissolved in a water / ethanol = 1 / 1 solution. 0.02% of the polymer's volume of DiI C18(3)(1,1-dioctadecyl-3,3,3,3-tetramethylindocarbocyanine perchlorate) (Fujifilm Wako) was mixed in. This was kept in the dark at 80°C for 20 minutes to obtain a 50% ethanol aqueous solution containing 1% fluorescently labeled polymer A (fluorescently labeled polymer A solution).

[0053] [Table 3]

[0054] The selective adhesion of the prepared Reference Example 1 composition to the incompletely keratinized stratum corneum was evaluated. Stratum corneum was collected from the face of a 46-year-old female subject using stratum corneum tape.

[0055] Next, the stratum corneum tape was immersed in the composition of Reference Example 1 for 30 seconds, and then washed with a polymer-free citrate buffer aqueous solution (an aqueous solution containing citric acid and sodium citrate, pH 4.6) obtained by removing fluorescently labeled polymer A from the composition of Reference Example 1. The stratum corneum tape was placed on a glass slide with the side with the stratum corneum attached facing upwards, purified water was dropped onto the stratum corneum tape, a coverslip was placed on top, and transmitted light observation and fluorescence observation were performed using an upright microscope with an excitation filter GW (wavelength 530-550 nm). The results are shown in Figure 3.

[0056] Figure 3 shows that the areas of incomplete keratinization with a high concentration of nucleated cells overlap with the areas where fluorescently labeled polymer A is present in Reference Example 1. Therefore, it is suggested that fluorescently labeled polymer A in Reference Example 1 selectively adheres to rough skin areas.

[0057] Next, the components shown in Table 4 were mixed to prepare the compositions of Reference Example 2 and Reference Example 3. Prior to this, a fluorescently labeled composite polymer B solution was prepared. 1 g of polyquaternium-10 was added to 20 ml of dimethyl sulfoxide containing 80 μl of pyridine and dissolved by stirring in a water bath at 70°C for 30 minutes. 0.1 g of fluorescein 5-isothiocyanate and 40 μl of dibutyltin dilaurate were added and incubated at the same temperature as during dissolution for 3 hours. Then, acetone was added to precipitate the polymer, and the solution was filtered. The same washing procedure was repeated until the filtrate was colorless, and the solution was left in acetone overnight. The next day, the solution was filtered and dried under reduced pressure at 40°C to obtain fluorescently labeled polyquaternium-10. A 1% aqueous solution of the anionic polymer (dimethylacrylamide / sodium acryloyldimethyltaurate) crosspolymer and a 1% aqueous solution of the cationic polymer fluorescently labeled polyquaternium-10 were mixed in a 2:1 ratio to obtain an aqueous solution containing 1% of the composite polymer (fluorescently labeled composite polymer B solution).

[0058] [Table 4]

[0059] The selective adhesion of the prepared Reference Examples 2 and 3 compositions to rough skin was evaluated. First, a 10% SDS aqueous solution was applied to the forearm of a 48-year-old female subject for 1 hour to induce skin roughness. The compositions of Reference Examples 2 and 3 were then applied to both normal and rough skin. After 1 minute, the applied compositions were removed by washing with tap water. The normal skin (no application group), as well as the normal and rough skin treated with the compositions, were imaged using a fluorescence video microscope (Dino-Lite Edge M Fluorescence GFBW, Sanko). The results are shown in Figure 4.

[0060] Figure 4 shows that the composition of Reference Example 2 is present in large quantities on the rough skin areas. Therefore, it is suggested that the fluorescently labeled composite polymer B in Reference Example 2 selectively adheres to the rough skin areas.

[0061] Evaluation of the impact on skin texture The cosmetic composition of Example 2 was prepared by a conventional method using the formulation shown in Table 5.

[0062] [Table 5]

[0063] The effects of the cosmetics of Example 1, Example 2, and Comparative Example 1 on the texture of the skin were evaluated. A 10% SDS aqueous solution was applied to the forearm of a 48-year-old female subject for 1 hour to induce skin roughness on the forearm. The cosmetics of Example 1, Example 2, and Comparative Example 1 were applied twice a day, morning and evening. Forty-eight hours after the induction of skin roughness, a total of four areas—the areas where the cosmetics were applied and the areas where the cosmetics were not applied (no application group)—were photographed using a video microscope (Keyence). The results are shown in Figure 5.

[0064] Figure 5 shows that in the areas where the cosmetics of Examples 1 and 2 were applied, while the areas where the cosmetics of Example 1 and 2 were applied tended to have skin furrows flowing in a certain direction, skin furrows perpendicular to that direction were formed, indicating a better skin texture.

Claims

1. It is a cosmetic product designed to act intensively on rough areas of the skin. Anionic polymers, and water It includes, The anionic polymer has at least one load electroactive group selected from the group consisting of sulfate groups, sulfate groups, sulfonic acid groups, sulfonate groups, phosphate groups, phosphonic acid groups, phosphonate groups, carboxyl groups, and carboxylate groups, or a salt thereof. A cosmetic composition having a pH of 5.5 or less.

2. The cosmetic composition according to claim 1, wherein the load-electric group is a sulfate group or a sulfonic acid group.

3. The cosmetic composition according to claim 1, wherein the anionic polymer is selected from the group consisting of acrylic polymers, urethane polymers, silicone polymers, and polysaccharides or their derivatives.

4. The cosmetic composition according to claim 1, wherein the anionic polymer is selected from the group consisting of (hydroxyethyl acrylate / sodium acryloyldimethyltaurate) copolymer, (sodium acrylate / sodium acryloyldimethyltaurate) copolymer, (acrylamide / sodium acryloyldimethyltaurate) copolymer, (ammonium acryloyldimethyltaurate / beheneth-25 methacrylate) crosspolymer, (ammonium acryloyldimethyltaurate / vinylpyrrolidone) copolymer, (sodium acryloyldimethyltaurate / dimethylacrylamide) crosspolymer, and sulfated polysaccharides.

5. The anionic polymer has the following repeating units: 【Chemistry 1】 (In the formula, R １ is hydrogen or methyl, R ２ C １－１０ It is a hydrocarbon group, X is the aforementioned load electrochemical group or a salt thereof. A cosmetic composition according to claim 1, comprising:

6. The cosmetic composition according to claim 1, wherein the anionic polymer is in the form of polymer particles.

7. The cosmetic composition according to claim 1, wherein the anionic polymer selectively adheres to rough areas of the skin.

8. A cosmetic composition according to any one of claims 1 to 7, for improving the texture, feel, or appearance of the skin.

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