Face pack cosmetic

Abstract

This face pack cosmetic contains polyvinyl alcohol and a salt of ascorbyl palmitate phosphate. The face pack cosmetic preferably contains 0.1-2.0 mass% of the salt of ascorbyl palmitate phosphate. The face pack cosmetic preferably contains 0.1-20 mass% of the polyvinyl alcohol.

Description

Packaged cosmetics

[0001] The present invention relates to packaged cosmetics. This application claims priority based on Japanese Patent Application No. 2024-189812 filed in Japan on October 29, 2024, and incorporates its content herein by reference.

[0002] Packaged cosmetics cover the skin with a film for a certain period of time. Packaged cosmetics are used for the purpose of replenishing moisture to the skin and softening the skin by suppressing the evaporation of moisture from under the skin. Conventionally, there are packaged cosmetics containing polyvinyl alcohol. Polyvinyl alcohol has excellent film-forming ability.

[0003] For example, Patent Document 1 discloses a packaged cosmetic containing (a) polyvinyl alcohol, (b) ascorbic acid and its derivatives, and (c) urea. Patent Document 1 also describes a packaged cosmetic in which the component (b) is a 2-O-D-glucopyranosyl-L-ascorbic acid derivative. Patent Document 1 also describes a packaged cosmetic containing 1.0 to 40.0% by mass of component (a), 0.1 to 10.0% by mass of component (b), and 0.1 to 5.0% by mass of component (c).

[0004] Further, Patent Document 2 describes a packaged cosmetic containing (a) 5 to 20% by mass of polyvinyl alcohol and (b) 0.01 to 10% by mass of silicic anhydride-coated titanium oxide, and the coating amount of silicic anhydride in the silicic anhydride-coated titanium oxide is 5 to 20% by mass. Patent Document 2 also describes a packaged cosmetic containing a water-soluble ascorbic acid derivative and / or a water-soluble glycyrrhizic acid derivative as component (e).

[0005] JP-A-2005-60237 JP-A-2004-217642

[0006] In recent years, there has been a growing demand for improving the appearance of visible pores on the face. In particular, there is a strong demand for improving the appearance of visible pores on the nose and the cheeks around the nose. One of the causes of visible pores is a change in the shape of the pore opening due to a decrease in skin elasticity. Specifically, it is known that the shape of the pore opening changes from a roughly circular shape to an oval shape, and when it connects with other adjacent pore openings, a band-like appearance is formed, further exacerbating the appearance of visible pores.

[0007] Therefore, there is a demand for facial pack cosmetics that can improve the appearance of pores on the face. Furthermore, there is a demand for facial pack cosmetics that can improve not only the appearance of pores on the face, but also fine wrinkles and rough skin on the face. The present invention has been made in view of the above problems, and aims to provide a facial pack cosmetic that can improve the appearance of pores on the face, fine wrinkles and rough skin on the face.

[0008] The inventors focused on ascorbic acid derivatives and conducted diligent research as described below in order to solve the above problems and realize a pack cosmetic that can improve the appearance of facial pores, fine wrinkles, and rough skin. As a result, among ascorbic acid derivatives modified with various substituents, it was found that the salt of ascorbyl palmitate phosphate, in particular, is converted to ascorbic acid by skin enzymes when applied to the skin surface. From this finding, it is presumed that a pack cosmetic containing a salt of ascorbyl palmitate will generate a large amount of ascorbic acid in the skin and provide high physiological activity.

[0009] Therefore, the inventors manufactured a cosmetic composition containing a salt of ascorbyl palmitate and investigated its effects on improving visible pores, fine wrinkles, and rough skin on the face. As a result, they inferred that a pack cosmetic composition containing a salt of ascorbyl palmitate has an excellent effect on improving visible pores, fine wrinkles, and rough skin on the face, and thus conceived the present invention. The present invention provides the following means.

[0010] [1] A pack cosmetic comprising polyvinyl alcohol and a salt of ascorbyl palmitate phosphate. [2] The pack cosmetic according to [1], wherein the salt of ascorbyl palmitate phosphate is the sodium salt of ascorbyl palmitate phosphate.

[0011] [3] The pack cosmetic composition according to [1] or [2], containing 0.1% to 2.0% by mass of the salt of ascorbyl palmitate phosphate. [4] The pack cosmetic composition according to [1] or [2], containing 0.1% to 20% by mass of the polyvinyl alcohol.

[0012] [5] The pack cosmetic composition according to [1] or [2], which contains 0.1% to 2.0% by mass of the salt of ascorbyl palmitate phosphate and 0.1% to 20% by mass of the polyvinyl alcohol.

[0013] The present invention's face pack cosmetic composition contains polyvinyl alcohol and a salt of ascorbyl palmitate phosphate. Therefore, the present invention's face pack cosmetic composition can improve the appearance of facial pores, fine wrinkles, and rough skin.

[0014] The following describes in detail the cosmetic pack according to this embodiment. The scope of the present invention is not limited to the embodiment described herein, and various modifications can be made without departing from the spirit of the invention. Furthermore, if multiple upper and lower limits are specified for a particular parameter, any upper and lower limit can be combined from among these upper and lower limits to obtain a suitable numerical range.

[0015] [Pack cosmetic] The pack cosmetic of this embodiment contains polyvinyl alcohol and a salt of ascorbyl palmitate phosphate.

[0016] (Polyvinyl Alcohol) The polyvinyl alcohol contained in the pack cosmetic of this embodiment imparts a film-forming function to the pack cosmetic and also has the function of adjusting the viscosity of the pack cosmetic. As the polyvinyl alcohol, known types such as those used as cosmetic raw materials can be used and can be appropriately selected according to the dosage form and shape of the pack cosmetic, and is not limited by the degree of saponification and / or molecular weight (degree of polymerization). The polyvinyl alcohol contained in the pack cosmetic of this embodiment may be only one type, or it may contain two or more types with different degrees of saponification and / or molecular weight (degree of polymerization).

[0017] The polyvinyl alcohol contained in the cosmetic pack of this embodiment may, for example, have a degree of saponification in the range of 70 mol% to 90 mol%, or in the range of 85 mol% to 98 mol%. Furthermore, as the polyvinyl alcohol, for example, those in which the viscosity of a 4% by mass aqueous solution at 20°C, which varies depending on the degree of polymerization, is in the range of 2 mPa·s to 5 mPa·s, 20 mPa·s to 30 mPa·s, 30 mPa·s to 45 mPa·s, or 40 mPa·s to 70 mPa·s can be suitably used.

[0018] The polyvinyl alcohol contained in the pack cosmetic of this embodiment preferably has a degree of saponification in the range of 85 mol% to 90 mol%, and the viscosity of a 4% by mass aqueous solution at a temperature of 20°C is preferably in the range of 35 mPa·s to 50 mPa·s. The reason for this is that when the pack cosmetic is, for example, a peel-off type with a gel-type formulation, it is easier to use and results in a pack cosmetic with better effects in improving the appearance of facial pores, fine wrinkles, and rough skin.

[0019] As for polyvinyl alcohol, commercially available products for cosmetic use can be used. Examples of commercially available polyvinyl alcohols for cosmetic use include Kuraray Poval (manufactured by Kuraray Co., Ltd.), Denka Poval (manufactured by Denka Co., Ltd.), and Gosenol (manufactured by Mitsubishi Chemical Corporation). Among these, it is preferable to use Gosenol (manufactured by Mitsubishi Chemical Corporation) EG-40C, which has a saponification degree in the range of 85 mol% to 90 mol% and a viscosity of 35 mPa·s to 50 mPa·s for a 4% by mass aqueous solution at 20°C. The reason for this is that it can easily form a film when applied to the skin, and the film, after being left on the skin for a predetermined time, is easily peeled off the skin, resulting in a pack cosmetic. As a result, it is a pack cosmetic that has a better effect in improving the appearance of facial pores, fine wrinkles, and rough skin.

[0020] The pack cosmetic of this embodiment preferably contains 0.1% to 20% by mass of polyvinyl alcohol. When the polyvinyl alcohol content is 0.1% by mass or more, the film-forming function and the function of adjusting the viscosity of the pack cosmetic due to the presence of polyvinyl alcohol are sufficiently obtained. As a result, the pack cosmetic has good usability, spreading in a film-like manner on the skin surface and remaining on the skin surface for a sufficient amount of time. The polyvinyl alcohol content is preferably 10% by mass or more, and more preferably 12% by mass or more. Furthermore, when the polyvinyl alcohol content is 20% by mass or less, it is possible to prevent the polyvinyl alcohol from having an adverse effect of hindering the penetration of the ascorbyl palmitate phosphate salt contained in the pack cosmetic into the skin. The polyvinyl alcohol content is preferably 18% by mass or less, and more preferably 15% by mass or less.

[0021] (Salt of Ascorbyl Palmitate Phosphate) The salt of ascorbyl palmitate phosphate contained in the pack cosmetic of this embodiment is an amphiphilic ascorbic acid derivative obtained by adding palmitic acid to a hydrophilic ascorbyl phosphate salt, which is an ascorbic acid (vitamin C) derivative, to give it lipophilicity. The salt of ascorbyl palmitate phosphate may be any salt selected from, for example, a sodium salt or a potassium salt. The salt of ascorbyl palmitate phosphate contained in the pack cosmetic of this embodiment may be only one type, or two or more types of salts. The salt of ascorbyl palmitate phosphate is preferably a sodium salt.

[0022] When the pack cosmetic of this embodiment is applied to the skin surface, the salt of ascorbyl palmitate phosphate contained in the pack cosmetic is readily converted to ascorbic acid by skin enzymes. This is because the salt of ascorbyl palmitate phosphate is amphiphilic and therefore easily penetrates the skin, and the structures derived from the phosphate ester and the structures derived from palmitic acid are rapidly broken down by skin enzymes.

[0023] Therefore, when the pack cosmetic of this embodiment is applied to the skin surface, a large amount of ascorbic acid is generated from the salt of ascorbyl palmitate phosphate contained in the pack cosmetic. As a result, it is presumed that high physiological activity derived from ascorbic acid is obtained. In other words, it is thought that the functions of ascorbic acid, which prevent the oxidation of sebum and improve the condition of the stratum corneum, and which improve the elasticity of the skin, will result in improved effects on the appearance of facial pores, fine wrinkles on the face, and rough skin.

[0024] The pack cosmetic of this embodiment preferably contains the sodium salt of ascorbyl palmitate phosphate represented by the following formula (1) (hereinafter sometimes referred to as "APPS"). APPS is less likely to precipitate within the pH range preferred for pack cosmetics. Therefore, pack cosmetics containing APPS can prevent APPS from precipitation in the pack cosmetic, which would make it difficult to decompose by skin enzymes. Consequently, pack cosmetics containing APPS, when applied to the skin surface, are more likely to generate ascorbic acid, and thus more likely to improve the appearance of facial pores, fine wrinkles, and rough skin. The sodium salt of ascorbyl palmitate phosphate represented by formula (1) is sold by Resonaq Co., Ltd. under the trade name "Apprecie®".

[0025]

[0026] The pack cosmetic of this embodiment preferably contains 0.1% to 2.0% by mass of a salt of ascorbyl palmitate. When the content of ascorbyl palmitate is 0.1% by mass or more, sufficient improvement effects on the appearance of facial pores, fine wrinkles, and rough skin due to the inclusion of ascorbyl palmitate can be obtained. The content of ascorbyl palmitate is preferably 0.2% by mass or more, and more preferably 0.5% by mass or more. Furthermore, when the content of ascorbyl palmitate is 2.0% by mass or less, it is possible to prevent the ascorbyl palmitate phosphate contained in the pack cosmetic from decomposing and discoloring the pack cosmetic to a yellowish-brown to reddish-brown color. Also, even if more than 2.0% by mass of ascorbyl palmitate is included, the function of the pack cosmetic does not improve. For this reason, the content of ascorbyl palmitate phosphate is preferably 2.0% by mass or less. The content of ascorbyl palmitate phosphate is preferably 1.5% by mass or less, and more preferably 1.0% by mass or less.

[0027] (Other ingredients) The cosmetic pack of this embodiment may contain, as needed, one or more other ingredients other than polyvinyl alcohol and ascorbyl palmitate phosphate salt, along with polyvinyl alcohol and ascorbyl palmitate phosphate salt.

[0028] Other ingredients that can be used include known ingredients used in face mask cosmetics. Other ingredients can be included in amounts that do not impair the effects of the present invention. Examples of other ingredients include solvents, humectants, oils and fats, solubilizers, surfactants, preservatives, adsorbents and abrasives, pH adjusters, antioxidants, UV absorbers, fragrances, colorants such as pigments and dyes, and cosmetic agents.

[0029] As a solvent, one capable of dissolving polyvinyl alcohol and ascorbyl palmitate phosphate salts can be used. The solvent preferably contains water, and most preferably contains only water. The solvent content in the cosmetic pack can be, for example, 1% to 85% by mass, and preferably in the range of 45% to 80% by mass.

[0030] As a humectant, one or more known humectants used in pack cosmetics can be used. Examples of humectants include 1,3-butylene glycol (BG), propylene glycol, dipropylene glycol (DPG), pentylene glycol, glycerin, and diglycerin. Among these humectants, 1,3-butylene glycol is preferred because it causes less irritation to the skin and forms a film when applied to the skin. The humectant content in the pack cosmetic can be, for example, 1% to 20% by mass, and is preferably in the range of 5% to 10% by mass.

[0031] As for the oils and fats, one or more known oils and fats used in pack cosmetics can be used. For example, synthetic ester oils and / or natural oils and fats can be used. Examples of synthetic ester oils include triglycerides such as triethylhexanoin, isopropyl myristate, cetyl ethylhexanoate, and isostearyl isostearate. Examples of natural oils and fats include olive oil, macadamia nut oil, castor oil, and coconut oil. Among these oils and fats, it is preferable to include triethylhexanoin because it has little effect on the stability of the ascorbyl palmitate phosphate salt and results in a pack cosmetic with a good feel. The oil and fat content in the pack cosmetic can be, for example, 1% to 25% by mass, and is preferably in the range of 2% to 15% by mass.

[0032] Ethanol can be used as a drying accelerator. The amount of drying accelerator contained in the cosmetic pack can be, for example, 0.5% to 60% by mass, and preferably in the range of 0.5% to 20% by mass.

[0033] As an emulsifier, one or more types can be selected from polyethylene glycol (PEG)-based surfactants such as polyethylene glycol laurate (PEG-12 laurate) and PEG-40 hydrogenated castor oil (polyoxyethylene hydrogenated castor oil), and polyglycerin fatty acid ester-based surfactants such as polyglyceryl-10 dioleate, polyglyceryl-5 oleate, polyglyceryl-5 stearate, and polyglyceryl-6 caprylate, which have an HLB value (Hydrophile-lipophile balance value) of about 12 to 14. Among these emulsifiers, it is preferable to include PEG-40 hydrogenated castor oil because it is highly versatile and leaves a good residue after peeling off the film made of the pack cosmetic.

[0034] The amount of emulsifier contained in the cosmetic pack can be appropriately determined depending on the type and amount of polyvinyl alcohol contained in the cosmetic pack, and the type and amount of other ingredients. For example, it can be 0.5% to 10% by mass, and is preferably in the range of 1.5% to 5% by mass.

[0035] As preservatives, one or more known preservatives used in cosmetic packs can be used. Examples of preservatives include methylparaben, phenoxyethanol, benzoic acid, salicylic acid, and sorbic acid. Among these preservatives, methylparaben and / or phenoxyethanol are preferred because they have little effect on the stability of the ascorbyl palmitate phosphate salt.

[0036] When methylparaben and phenoxyethanol are used as preservatives, the methylparaben content in the pack cosmetic can be, for example, 0.01% to 2% by mass, and the phenoxyethanol content in the pack cosmetic can be, for example, 0.05% to 5% by mass.

[0037] As adsorbent and abrasive, one or more known adsorbent and abrasives used in cosmetic packs can be used. Examples of adsorbent and abrasives include kaolin, hydroxyapatite, montmorillonite, and titanium dioxide (TIO). ２ ), silica, charcoal, bentonite, etc. can be used, and it is preferable that it contains kaolin, a natural hydrated aluminum silicate called kaolinol. The content of adsorbent and abrasive agents contained in the pack cosmetic can be, for example, 0.5% to 15% by mass, and is preferably in the range of 1% to 5% by mass.

[0038] As pH adjusting agents, one or more known ones used as pH adjusting agents in cosmetic packs can be used. Examples of pH adjusting agents include citric acid, sodium hydroxide, potassium citrate, and arginine. Citric acid and sodium hydroxide are preferred because they make it easier to obtain cosmetic packs with a stable pH.

[0039] When citric acid and sodium hydroxide are used as pH adjusters, the citric acid content in the cosmetic pack can be, for example, 0.01% to 1% by mass, and the sodium hydroxide content in the cosmetic pack can be, for example, 0.01% to 1% by mass. The pH of the cosmetic pack in this embodiment is preferably in the range of 7.0 to 8.5, and more preferably in the range of 7.5 to 8.0, in order to ensure that the salt of ascorbyl palmitate is stably incorporated.

[0040] (Manufacturing Method) The cosmetic pack of this embodiment can be manufactured, for example, by the method shown below. First, polyvinyl alcohol and the other components included as needed are mixed and stirred in water as a solvent. This results in a first solution in which each of the above components is dissolved and / or dispersed in water. The first solution can be manufactured using known stirring methods, such as dissolving using a tabletop stirrer or mixer. The first solution may also be manufactured, for example, by mixing and stirring each of the above components with water while heating to a temperature of 50°C to 80°C.

[0041] Next, the salt of ascorbyl palmitate phosphate is added to the first solution and mixed to form the second solution. Then, if necessary, the pH of the second solution is adjusted using a pH adjusting agent to reach the desired pH. Subsequently, the concentration of the second solution is adjusted by adding water. By this method, a pack cosmetic is obtained.

[0042] The packed cosmetic of this embodiment may be in a gel form or a sheet form, and the dosage form of the packed cosmetic is not particularly limited. Further, examples of the form of the packed cosmetic of this embodiment include a peel-off type, a wipe-off type, a rinse-off type, a sheet type, and the like. Among these, a peel-off type of packed cosmetic is preferred. The reason is that the salt of ascorbyl palmitate phosphate can penetrate the skin in a short time, so that enlarged pores on the face, fine wrinkles on the face, and rough skin can be improved more effectively.

[0043] The packed cosmetic of this embodiment contains polyvinyl alcohol and a salt of ascorbyl palmitate phosphate. Therefore, according to the packed cosmetic of this embodiment, by applying it to the skin surface, the functions of ascorbic acid generated from the salt of ascorbyl palmitate phosphate can improve enlarged pores on the face, fine wrinkles on the face, and rough skin.

[0044] As described above, the preferred embodiments of the present invention have been described in detail, but the present invention is not limited to specific embodiments, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims.

[0045] "Example 1" Gosenol EG-40C (manufactured by Mitsubishi Chemical Corporation), which is polyvinyl alcohol, 1,3-butylene glycol (BG), triethylhexanoin, ethanol, PEG-40 hydrogenated castor oil, methylparaben, phenoxyethanol, and kaolin (manufactured by Takehara Chemical Industry Co., Ltd.) were mixed with 70 g of purified water in the blending amounts shown in Table 1, and stirred while heating to 80°C to obtain a uniform first solution. Then, the first solution was cooled to room temperature by allowing it to cool.

[0046] Next, ascorbyl palmitate phosphate Na salt (APPS (Aprésie (registered trademark): manufactured by Resona Co., Ltd.)) was added to the first solution in the compounding amounts shown in Table 1 and mixed to obtain a second solution. Then, the pH of the second solution was adjusted to a pH in the range of 7.5 to 8.0 using citric acid and sodium hydroxide as pH adjusters. Further, purified water was added to the second solution so that the total amount became 100 g, thereby performing concentration adjustment. By the above method, the gel-like packed cosmetic of Example 1 was obtained.

[0047]

[0048] "Reference Experimental Example 1" Polyglyceryl-10 oleate, polyglyceryl-2 oleate, and squalane were mixed with 43.4 g of purified water in the compounding amounts shown in Table 2 to obtain a uniform first solution. Then, BG, methylparaben, and propylparaben were mixed with the first solution in the compounding amounts shown in Table 2 to obtain a second solution. Next, glycerin and purified water were mixed with the second solution in the compounding amounts shown in Table 2 to obtain a third solution, and APPS, which is ascorbyl palmitate phosphate 3Na, was added to the third solution in the compounding amounts shown in Table 2 and mixed, and purified water was added so that the total amount became 100 g to perform concentration adjustment. By the above method, the cosmetic of Reference Experimental Example 1 was obtained. Also, the pH of the cosmetic of Reference Experimental Example 1 was 7.5 to 8.0.

[0049]

[0050] "Comparative Example 1 of Reference Experimental Example 1" (hereinafter referred to as Comparative Example 1) A cosmetic of Comparative Example 1 was obtained in the same manner as in Reference Experimental Example 1, except that water having the same mass as ascorbyl palmitate phosphate 3Na was added instead of APPS.

[0051] Using the cosmetics of Reference Experimental Example 1 and Comparative Example 1 thus obtained, by the method shown below, the shape change of the pore openings on the face, the shape change of fine wrinkles, the improvement effect on skin roughness, and the usage feeling by using the cosmetic were examined.

[0052] Each of the subjects listed below used the product as a cosmetic twice a day, morning and night, after washing their face, according to the instructions below, for the test period described below. (Subjects) 23 women who identified as having enlarged pores (average age 46.2 ± 7.7 years). (Instructions for use) The cosmetic was applied to half of the face, including the nose and the area around the nose. (Test period) 8 weeks between August and November 2022. The entire face before the start of the test and the entire face after the end of the test were photographed using a facial imaging device (NEWTONE Technologies, "ColorFace").

[0053] [Changes in the shape of facial pore openings] The following evaluations were performed to assess changes in facial pores. First, in the full-face images of each subject obtained before and after the test, pores were identified in the cheek area around the nose on the side where the cosmetic was applied, and 50 pores were selected for measurement.

[0054] (Measurement of Roundness) For 50 pores, the roundness of the pore opening was calculated using analysis software from NEWTONE Technologies, according to the definition below. The average value for all subjects was obtained from the roundness of the pore openings of each subject. The results are shown in Table 3.

[0055] (Definition of roundness) The shape of each pore opening was considered to be circular, and the distance between two points on the circumference passing through the center of the circle was measured at multiple points for each pore opening. The ratio of the maximum and minimum values ​​was calculated and defined as the roundness of the pore opening.

[0056]

[0057] The closer the value of roundness is to 1, the closer it is to a perfect circle. Also, facial pores are less noticeable the closer the shape of the pore opening is to a perfect circle. From Table 3, it can be seen that in Reference Experiment Example 1, which used a cosmetic product containing APPS, the roundness after the test approached 1. From this, it can be inferred that Reference Experiment Example 1 showed an improvement in the visibility of facial pores. This effect is presumed to be due to the function of ascorbic acid produced from APPS in improving skin elasticity.

[0058] In contrast, in Comparative Example 1, which contained water instead of APPS, the roundness after the test approached 1, but the change was only slight compared to Reference Experiment Example 1.

[0059] [Changes in the Shape of Facial Micro-Wrinkles] For each subject, the area, length, and volume of micro-wrinkles on the cheek around the nose on the side where the cosmetic was applied were measured by analyzing full-face images taken before and after the test using analysis software from NEWTONE Technologies. The micro-wrinkles analyzed were shallow, fine wrinkles caused by changes in the shape of the stratum corneum surface. From each measurement, the ratio of the value after the test to the value before the test (a value with the pre-test value set to 1.0) was calculated, and the average value for all subjects was calculated from the results for each subject. The results are shown in Table 4.

[0060] (Area of ​​micro-wrinkles) This indicates the area of ​​micro-wrinkles present on the cheek around the nose on the side where the cosmetic was applied, as seen in the full-face image. (Length of micro-wrinkles) This indicates the length from one end to the other of each micro-wrinkle present on the cheek around the nose on the side where the cosmetic was applied, as seen in the full-face image. (Volume of micro-wrinkles) The depth of each micro-wrinkle was measured by image analysis, and the average value was calculated. Then, the volume of the micro-wrinkles was calculated by multiplying the depth by the area of ​​the micro-wrinkles mentioned above.

[0061]

[0062] As shown in Table 4, in Reference Experiment Example 1, which used a cosmetic product containing APPS, the values ​​after the end of the test were smaller than the values ​​before the start of the test in terms of area, length, and volume of micro-wrinkles, compared to Comparative Example 1, which used a cosmetic product containing water instead of APPS, confirming a high improvement effect on facial micro-wrinkles. This effect is presumed to be due to the function of ascorbic acid, which is generated from APPS contained in the cosmetic product used in Reference Experiment Example 1, in improving skin elasticity.

[0063] [Skin roughness improvement effect] After taking a full-face image using the facial imaging device described above, and again after taking a full-face image after the test, a 5 mm wide, 12 mm long cellophane tape (product name: Cellotape®, manufactured by Nichiban Co., Ltd.) was pressed against the cheek area around the nose on the side where the cosmetic product was applied, and then peeled off to collect stratum corneum from the cheek area around the nose.

[0064] The collected stratum corneum was stained with Brilliant Green and Methyl Violet, and photographs were taken at 200x magnification under a microscope (TS-100; Nikon Corporation). The resulting microscopic images were analyzed using the stratum corneum analysis software "Corneocytometer (CIEL Corporation)" to determine the cell area and degree of multiple exfoliation of the stratum corneum in three fields of view for each subject before the start of the experiment and after the end of the experiment.

[0065] For each subject, the cell area of ​​the stratum corneum was measured by selecting 30 cells from each field of view, and the area per cell was determined. Furthermore, the degree of multiple exfoliation of the stratum corneum for each subject was calculated by determining the ratio of the area of ​​the heavily stained multiple exfoliation region to the total area of ​​stained cells across three fields of view. Then, the ratio of the value after the end of the test to the value before the start of the test (with the pre-test value set to 1.0) was calculated, and the average value for all subjects was calculated from the results for each subject. The results are shown in Table 5.

[0066]

[0067] The degree of multiple exfoliation of the stratum corneum is known as an indicator of rough skin. A smaller degree of multiple exfoliation of the stratum corneum indicates a better stratum corneum condition. As shown in Table 5, in Reference Experiment Example 1, which used a cosmetic product containing APPS, the value of the degree of multiple exfoliation after the end of the experiment was significantly smaller than the value before the start of the experiment, confirming a high effect in improving rough skin. This effect is presumed to be due to the function of ascorbic acid produced from APPS, which prevents the oxidation of sebum and improves the condition of the stratum corneum.

[0068] In contrast, in Comparative Example 1, where a cosmetic product containing water was used instead of APPS, the value of the degree of multiple peeling after the test was larger than the value before the test, and no improvement in skin roughness was confirmed.

[0069] Furthermore, a larger numerical value for the stratum corneum cell area indicates a higher barrier function of the stratum corneum. As shown in Table 5, in Reference Experiment Example 1, which used a cosmetic containing APPS, the value of the cell area after the end of the experiment was larger than the value before the start of the experiment, confirming that the barrier function of the stratum corneum had improved. This is presumed to be because, in Reference Experiment Example 1, the use of the cosmetic caused skin enzymes to produce ascorbic acid from APPS, and the function of ascorbic acid, which prevents the oxidation of sebum and improves the condition of the stratum corneum, improved skin roughness.

[0070] In contrast, in Comparative Example 1, where a cosmetic product containing water was used instead of APPS, the cell area value after the test was smaller than the value before the test, and no improvement in the barrier function of the stratum corneum was confirmed.

[0071] [User Experience] Each subject was given a questionnaire regarding the following items (1) to (3) to investigate their experience using the cosmetics. The results are shown in Table 6.

[0072]

[0073] As shown in Table 6, for all questionnaire items (1) to (3), Reference Experiment Example 1, which used cosmetics containing APPS, showed a higher percentage of subjects who answered "yes" compared to Comparative Example 1, which used cosmetics containing water instead of APPS.

[0074] [Experimental Example] Aqueous solutions of ascorbic acid derivatives, each containing one of the ascorbic acid derivatives listed below (1) to (5) at a concentration of 1% by mass, were prepared. Then, using each of the aqueous solutions of ascorbic acid derivatives containing one of the ascorbic acid derivatives (1) to (5), the amount converted to ascorbic acid by skin enzymes was measured using the method described below.

[0075] [Ascorbic Acid Derivatives] <1> Sodium salt of ascorbyl palmitate phosphate (APPS (Apprecie® registered trademark): manufactured by Resonac Co., Ltd.) <2> Glucoside ascorbic acid (AG: manufactured by Nagase Vita Co., Ltd.) <3> Ethyl ascorbic acid (EA: manufactured by Fujifilm Wako Pure Chemical Industries Ltd.) <4> Ascorbyl tetrahexyldecanoate (VC-IP: manufactured by Nikko Chemicals Co., Ltd.) <5> Caprylyl 2-glyceryl ascorbic acid (GO-VC: manufactured by ITO Co., Ltd.)

[0076] The 3D skin epidermis model (manufactured by Kurabo Industries Ltd.) was acclimatized by immersing it in 300 μL of a dedicated culture medium for 1 hour. 50 μL of an aqueous solution of ascorbic acid derivative containing one of the ascorbic acid derivatives <1> to <5> at a concentration of 1% by mass was applied to the surface of the acclimatized 3D skin epidermis model. This resulted in a surface area of ​​0.5 cm² on the 3D skin epidermis model. ２ The area was covered with an aqueous solution of an ascorbic acid derivative. The 3D skin epidermal model coated with the aqueous solution of the ascorbic acid derivative was left to stand for 24 hours, and the culture medium was collected.

[0077] The recovered culture medium was analyzed and quantified using high-performance liquid chromatography (manufactured by Shimadzu Corporation). The ascorbic acid contained in the recovered culture medium was obtained by converting one of the ascorbic acid derivatives <1> to <5> contained in the aqueous solution of ascorbic acid derivatives applied to the surface of the 3D skin epidermal model into ascorbic acid by skin enzymes and releasing it into the culture medium.

[0078] Therefore, using the quantitative value of the amount of ascorbic acid contained in the recovered culture medium, the area of ​​1 cm² coated with the ascorbic acid derivative aqueous solution was determined. ２ In this region, the amount of conversion per unit time from ascorbic acid derivatives to ascorbic acid by skin enzymes was calculated. The results are shown in Table 7.

[0079]

[0080] As shown in Table 7, the ascorbic acid derivative (APPS) of <1> showed a significantly higher conversion rate of ascorbic acid by skin enzymes compared to the ascorbic acid derivatives of <2> to <5>. From these results, it is presumed that when a pack cosmetic containing a salt of ascorbyl palmitate phosphate, such as APPS, is applied to the skin surface, the salt of ascorbyl palmitate phosphate is rapidly broken down, generating a large amount of ascorbic acid, and thus high physiological activity derived from ascorbic acid can be obtained.

Claims

1. A facial pack containing polyvinyl alcohol and a salt of ascorbyl palmitate phosphate.

2. The pack cosmetic composition according to claim 1, wherein the salt of ascorbyl palmitate phosphate is the sodium salt of ascorbyl palmitate phosphate.

3. The pack cosmetic composition according to claim 1 or claim 2, comprising 0.1% to 2.0% by mass of the salt of ascorbyl palmitate phosphate.

4. The pack cosmetic composition according to claim 1 or claim 2, comprising 0.1% to 20% by mass of the polyvinyl alcohol.

5. The pack cosmetic composition according to claim 1 or claim 2, comprising 0.1% to 2.0% by mass of the salt of ascorbyl palmitate phosphate and 0.1% to 20% by mass of the polyvinyl alcohol.

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