Emulsified cosmetics

Abstract

The present invention provides an emulsified cosmetic that reduces the sticky, unpleasant feeling in high-humidity environments or when sweating, while also moisturizing the skin and enhancing its beauty benefits in low-humidity environments. [Solution] The emulsified cosmetic composition of this disclosure comprises an aqueous phase containing water and polyvinyl alcohol, and an oil phase containing oil, wherein the polyvinyl alcohol content is 0.5% by mass or more of the total amount of the emulsified cosmetic composition.

Description

[Technical Field]

[0001] This disclosure relates to emulsified cosmetics. [Background technology]

[0002] In recent years, films with moisture-permeable properties have been used in various fields.

[0003] Patent Document 1 discloses a breathable film for use in clothing and the like, which contains a matrix resin and collagen powder made of cross-linked regenerated collagen, and has a degree of communication of 1 to 95%.

[0004] Patent Document 2 discloses a wound bed environment adjustment sheet that uses a moisture-permeable hydrogel sheet and is applied to the wound site of a skin injury. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2010-077202 [Patent Document 2] International Publication No. 2012 / 036064 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] For example, in Japan, humidity in outdoor environments tends to be high during the rainy season, while it tends to be considerably lower during the dry winter months. Furthermore, in recent years, due to the use of air conditioning, humidity levels in indoor workplaces and shopping centers have also become quite low. In such low-humidity environments, moisture evaporates from the skin, leading to dryness, and making skin problems such as roughness and wrinkles more likely.

[0007] To improve such skin problems, it is common practice to apply moisturizers such as glycerin to the skin. However, even if the moisturizing ingredients applied to the skin temporarily retain moisture from the skin and exhibit moisturizing properties, if the humidity of the outside air is low, the retained moisture will evaporate into the outside air over time, and sufficient moisturizing effect cannot be obtained. In addition, if you sweat while such a moisturizer is applied to your skin, the occlusion effect of the spread moisturizer makes it difficult for the sweat to evaporate into the outside air, which can easily cause a sticky and unpleasant feeling.

[0008] Furthermore, when a gel sheet with moisture-permeable properties, such as that described in Patent Document 2, is applied to the skin, sweat can easily evaporate into the outside air, and it is believed that moisturizing performance will be improved compared to when such a sheet is not applied to the skin. However, since such a sheet is always in a state of moisture permeability, in low-humidity environments, moisture from the skin is constantly evaporating through the sheet. Therefore, even when using a sheet with such moisture-permeable properties, in low-humidity environments where moisture easily evaporates from the skin, it is believed that sufficient moisturizing effects cannot be obtained, and skin problems such as rough skin cannot be adequately improved.

[0009] Therefore, the subject of this disclosure is to provide an emulsified cosmetic that can reduce the sticky discomfort in high-humidity environments or when sweating, while moisturizing the skin and enhancing its cosmetic effects in low-humidity environments. [Means for solving the problem]

[0010] <Aspect 1> Water, and an aqueous phase containing polyvinyl alcohol, An emulsified cosmetic composition comprising an oil phase containing oil, The polyvinyl alcohol content is 0.5% by mass or more relative to the total amount of the emulsified cosmetic composition. Emulsified cosmetic. <Aspect 2> The cosmetic according to aspect 1, wherein the content of the polyvinyl alcohol is 2.5% by mass or more based on the total amount of the emulsified cosmetic. <Aspect 3> The cosmetic according to aspect 1 or 2, wherein the oil component contains a nonpolar hydrocarbon oil. <Aspect 4> The cosmetic according to aspect 3, wherein the nonpolar hydrocarbon oil contains petrolatum. <Aspect 5> The cosmetic according to aspect 3 or 4, wherein the proportion of the nonpolar hydrocarbon oil in the oil component is 10% by mass or more. <Aspect 6> The cosmetic according to any one of aspects 1 to 5, wherein the mass ratio of polyvinyl alcohol to the remaining oil component when the emulsified cosmetic is applied to the skin is 0.60 or more. <Aspect 7> The cosmetic according to any one of aspects 1 to 6, wherein the mass ratio of polyvinyl alcohol to the remaining polar oil or silicone oil when the emulsified cosmetic is applied to the skin is each independently 0.01 or more. <Aspect 8> The cosmetic according to any one of aspects 1 to 7, further comprising inorganic particles. <Aspect 9> The cosmetic according to aspect 8, wherein the content of the inorganic particles is 10% by mass or less based on the total amount of the emulsified cosmetic. <Aspect 10> The cosmetic according to any one of aspects 1 to 9, wherein the emulsified cosmetic is an oil-in-water type or water-in-oil type emulsified cosmetic. <Aspect 11> The cosmetic according to any one of aspects 1 to 10, wherein when evaluated by a water vapor transmission test, the water permeation coefficient measured in an environment of 23°C and 40% RH or 28°C and 20% RH is smaller than the water permeation coefficient measured in an environment of 28°C and 70% RH. [Effect of the Invention]

[0011] According to the present disclosure, it is possible to provide an emulsified cosmetic that can reduce the sticky discomfort in a high humidity environment or when sweating, and can moisturize the skin and enhance the beauty effect in a low humidity environment.

Brief Description of the Drawings

[0012] [Figure 1] It is a schematic diagram showing the moisture shielding state when the emulsified cosmetic of the present disclosure is applied to the skin in a low humidity environment. [Figure 2] It is a schematic diagram showing the moisture permeation state when the emulsified cosmetic of the present disclosure is applied to the skin in a high humidity environment. [Figure 3] It is another schematic diagram showing the moisture shielding state when the emulsified cosmetic of the present disclosure is applied to the skin in a low humidity environment. [Figure 4] It is another schematic diagram showing the moisture permeation state when the emulsified cosmetic of the present disclosure is applied to the skin in a high humidity environment. [Figure 5] It is a schematic diagram of a measurement sample to which a polyvinyl alcohol-containing layer used in a moisture transpiration test is applied.

Embodiments for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present disclosure will be described in detail. The present disclosure is not limited to the following embodiments, and can be variously modified and implemented within the scope of the gist of the invention.

[0014] The emulsified cosmetic of the present disclosure includes an aqueous phase containing water and polyvinyl alcohol, and an oil phase containing an oil component, and the content of polyvinyl alcohol is 0.5% by mass or more based on the total amount of the emulsified cosmetic.

[0015] Although not limited by theory, the working principle by which the emulsified cosmetic of the present disclosure can reduce the sticky and unpleasant feeling in a high humidity environment or when sweating, and can moisturize the skin and enhance the beauty effect in a low humidity environment is considered as follows. In the present disclosure, polyvinyl alcohol may be abbreviated as "PVA".

[0016] When skin is exposed to dryness, it can lose moisture without us realizing it, and the stratum corneum on the skin's surface may not be able to retain enough moisture. When the skin lacks moisture, it becomes unable to produce its own moisturizing components (natural moisturizing factors (NMF)). As a result, the barrier function and moisturizing function on the skin's surface deteriorate, making the skin more susceptible to damage, and leading to a loss of moisture and causing skin roughness and other problems.

[0017] Furthermore, if the stratum corneum on the skin's surface remains deficient in moisture, the skin will try to repair the damaged stratum corneum by quickly creating new cells. This speeds up the skin's regeneration (turnover) process, but also leads to the creation of many immature and incomplete cells. As a result, the skin becomes insufficiently prepared to create a normal stratum corneum, making it unable to retain enough moisture on the skin's surface, leading to a vicious cycle of persistent skin irritation.

[0018] The emulsified cosmetic composition of this disclosure is expected to be applied to the skin in a configuration as shown in Figure 1 or Figure 3 when applied to the skin.

[0019] The first configuration 100 shown in Figure 1 is separated into a hydrophilic PVA layer 101 and a hydrophobic oil layer 109. When the emulsified cosmetic of this disclosure is applied to the skin, the oil layer 109 is formed because oil is more easily adsorbed than PVA on the generally hydrophobic skin surface. On the other hand, the hydrophilic PVA layer 101, which does not readily mix with the oil phase, is formed above the oil layer 109, resulting in the configuration shown in Figure 1. This configuration is thought to be more likely to form when the viscosity of the emulsified cosmetic is relatively low and the emulsion particles are easily movable, or in the case of an oil-in-water type emulsified cosmetic.

[0020] PVA is generally known to have excellent affinity for water. In the first configuration 100 shown in Figure 1, some of the water evaporated from the skin is shielded by the oil layer 109. However, since the oil layer 109 formed by the emulsified cosmetic composition of this disclosure is a thin layer, it is thought that some of the water can pass through this oil layer 109. The water that passes through the oil layer 109 binds with the PVA molecules 103 in the PVA layer 101, and as the PVA molecules 103 move in a way that attracts the water 105, a gap 107 that allows water to pass through is created. However, when the humidity of the external environment is low, the movement of PVA molecules 103 based on water is less likely to occur near the outermost surface of the PVA layer 101, so it is thought that a gap 107 that allows water to pass through is not formed. As a result, in a low-humidity environment, the water evaporated from the skin remains below the outermost surface of the PVA layer 101 and is not evaporated into the atmosphere, so it is thought that the skin can be sufficiently moisturized even in a low-humidity environment. This is thought to improve the skin's ability to produce its own moisturizing components and also correct any imbalances in the stratum corneum's turnover, making it less likely for skin problems such as roughness to occur and enhancing its beauty benefits.

[0021] Here, even if a PVA layer 101 as shown in Figure 1 is formed by the emulsified cosmetic composition of this disclosure, the thickness of that layer is usually considered to be thin. In the case of a thin PVA layer, if there is no oil layer 109 as shown in Figure 1, for example, when the skin has a high moisture content, gaps that allow water to pass through may be formed even in a low humidity environment, and moisture from the skin may evaporate. When the emulsified cosmetic composition of this disclosure is applied to the skin, it is considered that an oil layer 109 that can partially suppress moisture from the skin may also be placed below the PVA layer 101 layer, as shown in Figure 1. Therefore, even with a thin PVA layer, it is considered that the formation of gaps that allow water to pass through can be suppressed in a low humidity environment.

[0022] In high-humidity environments or when sweating profusely, as shown in Figure 2, for example, the PVA molecules 203 near the outermost surface of the PVA layer 201 also move, attracting moisture 205, resulting in the creation of moisture-permeable gaps 207 throughout the entire thickness of the PVA layer 201. As a result, in such conditions, excess moisture such as sweat can evaporate from the skin, thus reducing the sticky discomfort. Furthermore, in high-humidity environments where the skin is dry, it is thought that moisture from the environment can be supplied to the skin through the PVA layer 201.

[0023] The second configuration 300 shown in Figure 3 constitutes an oil layer 309 containing PVA particles 301 in a state where the PVA particles are dispersed in the oil. This configuration is thought to be easily formed when the viscosity of the emulsified cosmetic is relatively high and the emulsified particles do not move easily, or in the case of a water-in-oil type emulsified cosmetic.

[0024] In the case of the second configuration 300 as shown in Figure 3, for example, moisture evaporated from the skin binds with PVA molecules 303 in the PVA particles 301 located closer to the skin, and as the PVA molecules 303 move attracted to the moisture 305, a passage 307 through which the moisture can pass is thought to be created. However, if the humidity of the external environment is low, the movement of PVA molecules 303 is unlikely to occur in the PVA particles 301 near the outermost surface of the oil layer 309 containing the PVA particles, and therefore, a passage 307 through which the moisture can pass is not thought to be formed. As a result, in a low-humidity environment, moisture evaporated from the skin remains below the outermost surface of the oil layer 309 containing the PVA particles and is not evaporated into the atmosphere, so the skin can be sufficiently moisturized even in a low-humidity environment.

[0025] On the other hand, in a high-humidity environment or when sweating profusely, as shown in Figure 4, for example, the PVA molecules 403 near the outermost surface of the oil layer 409 containing PVA particles also move as they are attracted to each other by the water 405. As a result, it is thought that a passage 407 is created throughout the entire thickness of the oil layer 309 containing PVA particles that allows water to pass through. Consequently, in such conditions, excess moisture such as sweat can evaporate from the skin, thus reducing the sticky discomfort. Furthermore, even in this second configuration, in a high-humidity environment and when the skin is dry, it is thought that moisture from the environment can be supplied to the skin through the oil layer 409 containing PVA particles.

[0026] The definitions of terms used in this disclosure are as follows:

[0027] In this disclosure, "humidity responsiveness" means the ability to change the amount of moisture evaporation in response to changes in the humidity environment, and specifically, the ability to have a moisture transmission coefficient that is smaller in low-humidity environments than in high-humidity environments.

[0028] In this disclosure, "low humidity environment" means an environment with relative humidity at atmospheric pressure, 23°C or 28°C, where the relative humidity is less than 50%RH, 45%RH or less, 40%RH or less, 35%RH or less, 30%RH or less, 25%RH or less, or 20%RH or less. There are no particular restrictions on the lower limit of such relative humidity, but for example, it can be 3%RH or higher, 5%RH or higher, 7%RH or higher, or 10%RH or higher. Furthermore, such relative humidity can be converted to absolute humidity by weight, which is unaffected by temperature, and for example, the absolute humidity by weight can be 8.7g / kg or less, 7.9g / kg or less, 7.0g / kg or less, 6.1g / kg or less, 5.4g / kg or less, 5.2g / kg or less, 5.0g / kg or less, or 4.8g / kg or less, or 0.52g / kg or higher, 0.86g / kg or higher, 1.2g / kg or higher, or 1.7g / kg or higher.

[0029] In this disclosure, "high humidity environment" means an environment with a relative humidity of 50%RH or higher, 55%RH or higher, 60%RH or higher, 65%RH or higher, 70%RH or higher, or 75%RH or higher at atmospheric pressure and 28°C. There are no particular restrictions on the upper limit of such relative humidity, but for example, it can be 100%RH or less or less. Furthermore, such relative humidity can be converted to absolute humidity by weight, which is unaffected by temperature, and the absolute humidity by weight can be 12g / kg or higher, 13g / kg or higher, 14g / kg or higher, 15g / kg or higher, 17g / kg or higher, or 18g / kg or higher, or 24g / kg or less or less than 24g / kg.

[0030] In this disclosure, "cosmetics" or "cosmetics" means applying the emulsified cosmetic composition of this disclosure to the body surface to beautify and improve the condition of the body surface, or a method of beautifying and improving the condition of the body surface, and is different from methods of surgery, treatment, or diagnosis of human beings.

[0031] In this disclosure, "body surface" means the surface of the skin of the body.

[0032] Emulsified cosmetics The emulsified cosmetic composition of this disclosure can exhibit humidity responsiveness at the application site when applied to the body surface. Such humidity responsiveness can be evaluated by the moisture permeability coefficient (sometimes simply referred to as "permeability coefficient") calculated based on a moisture evaporation test.

[0033] The amount of water evaporation (g / hour) can be calculated as shown in Figure 5. This is done by covering the open end of a vial containing 20 mL of water with filter paper, applying an emulsified cosmetic to the entire surface of the filter paper, and allowing it to stand in a low-humidity environment (e.g., 28°C, 20% RH) until it reaches an equilibrium where the evaporation rate is approximately constant over time. The amount of water lost is then measured, and the amount of water lost per unit area and per unit time is calculated. (Permeability coefficient (mol·m / m)) 2The pressure (s·Pa) can be calculated using the rate of water evaporation from the following formula 1. Here, "specified temperature" and "specified humidity" refer to the temperature and relative humidity when the vial is left standing, and "permeable area" refers to the area of ​​the open part of the vial: Permeability coefficient (mol·m / m 2 (s·Pa) = [{(Moisture evaporation rate (g / hour) under a given temperature and humidity (m²) / 18 / 3600 / Permeable area (m²) 2 )} / (Water vapor pressure at a specified temperature and relative humidity of 100% (Pa) - Water vapor pressure at a specified temperature and humidity (Pa))] × Film thickness of filter paper (m) ... Equation 1

[0034] The emulsified cosmetic composition of this disclosure can exhibit humidity responsiveness, as evaluated in the moisture evaporation test described later, such that the transmission coefficient measured in a low humidity environment of 23°C / 40%RH or 28°C / 20%RH is smaller than the transmission coefficient measured in a high humidity environment of 28°C / 70%RH. In contrast, when the product is stored in an open system or in a vial covered with filter paper, the transmission coefficient measured in a low humidity environment of 23°C / 40%RH or 28°C / 20%RH is larger than the transmission coefficient measured in a high humidity environment of 28°C / 70%RH.

[0035] Furthermore, if the measurement environment is, for example, a lower humidity environment than 23°C and 40% RH, the emulsified cosmetic composition of this disclosure can more effectively suppress moisture evaporation. Therefore, the difference in moisture permeability coefficient tends to increase as the difference in humidity levels of the measurement environment widens.

[0036] The emulsified cosmetic composition of this disclosure may be any emulsified cosmetic composition comprising an aqueous phase and an oil phase, and may be either an oil-in-water type or a water-in-oil type.

[0037] <Oil-in-water emulsion cosmetic> The oil-in-water emulsion cosmetic composition of this disclosure comprises, as the aqueous phase, a dispersion medium containing water and polyvinyl alcohol, and as the oil phase, oil droplets containing oil dispersed in the dispersion medium, wherein the polyvinyl alcohol content is 0.5% by mass or more of the total amount of the emulsion cosmetic composition.

[0038] As described above, such oil-in-water emulsion cosmetics can exhibit humidity responsiveness at the application site when applied to the body surface.

[0039] (dispersion medium) The dispersion medium in the oil-in-water emulsion cosmetic composition of this disclosure comprises water and polyvinyl alcohol.

[0040] A. Water There are no particular restrictions on the water that can be used in the oil-in-water emulsion cosmetic composition of this disclosure; water used for cosmetics, quasi-drugs, etc., can be used. For example, ion-exchanged water, distilled water, ultrapure water, and tap water can be used.

[0041] There are no particular restrictions on the amount of water used; for example, it can be 30% by mass or more, 35% by mass or more, or 40% by mass or more relative to the total amount of the emulsified cosmetic, or it can be 90% by mass or less, 80% by mass or less, 70% by mass or less, 60% by mass or less, or 50% by mass or less.

[0042] B. Polyvinyl alcohol The polyvinyl alcohol that can be used in the oil-in-water emulsion cosmetic composition of this disclosure is not particularly limited as long as the area to which the emulsion cosmetic composition is applied exhibits humidity responsiveness, and polyvinyl alcohol or its derivatives can be used alone or in combination of two or more. Examples of polyvinyl alcohol derivatives include modified polyvinyl alcohol, polyvinyl acetate, and polyvinyl butyral. From the viewpoint of humidity responsiveness, unmodified polyvinyl alcohol and / or modified polyvinyl alcohol are preferred.

[0043] As polyvinyl alcohol, for example, fully saponified polyvinyl alcohol with a degree of saponification of 99% or more, partially saponified polyvinyl alcohol with a degree of saponification of 90% or more and less than 99%, and partially saponified polyvinyl alcohol with a degree of saponification of 70% or more and less than 90% can be used. These polyvinyl alcohols can be used alone or in combination of two or more. Among these, fully saponified polyvinyl alcohol and partially saponified polyvinyl alcohol are preferred from the viewpoint of humidity responsiveness, in particular the effect of suppressing moisture evaporation in low humidity environments, and fully saponified polyvinyl alcohol is more preferred. Examples of modification treatments for polyvinyl alcohol include diol modification, anion modification, and cationic modification.

[0044] From the viewpoint of humidity responsiveness, particularly the effect of suppressing moisture evaporation in low humidity environments, unmodified polyvinyl alcohol or diol-modified polyvinyl alcohol is preferred, and unmodified polyvinyl alcohol is more preferred.

[0045] Such polyvinyl alcohols can be commercially available. Examples of unmodified, fully saponifiable polyvinyl alcohols include Gosenol™ NL-05 (manufactured by Mitsubishi Chemical Corporation), KURARAY POVAL™ PVA-117H (manufactured by Kuraray Co., Ltd.), and KURARAY POVAL™ PVA-124 (manufactured by Kuraray Co., Ltd.). An example of anionically modified, fully saponifiable polyvinyl alcohol is Gosenex™ T-330H (manufactured by Mitsubishi Chemical Corporation). Examples of diol-modified, fully saponifiable polyvinyl alcohols include Nichigo G Polymer™ OKS-1089 and Nichigo G Polymer™ OKS-1109 (both manufactured by Mitsubishi Chemical Corporation).

[0046] Examples of unmodified partially saponified polyvinyl alcohol include KURARAY POVAL (trademark) PVA-617 (manufactured by Kuraray Co., Ltd.), and examples of diol-modified partially saponified polyvinyl alcohol include Nichigo G Polymer (trademark) OKS-8096 (manufactured by Mitsubishi Chemical Corporation).

[0047] Examples of unmodified partially saponified polyvinyl alcohols include Gosenol® GM-14, Gosenol® PVA EG-05, Gosenol® PVA EG-40 (all manufactured by Mitsubishi Chemical Corporation), and KURARAY POVAL® PVA-235 (manufactured by Kuraray Co., Ltd.). An example of a cationically modified partially saponified polyvinyl alcohol is Gosenol® PVA K-434 (manufactured by Mitsubishi Chemical Corporation).

[0048] The amount of polyvinyl alcohol can be 0.7% by mass or more, 1.0% by mass or more, 1.5% by mass or more, 2.0% by mass or more, 2.5% by mass or more, 3.0% by mass or more, 3.5% by mass or more, or 4.0% by mass or more, relative to the total amount of the emulsified cosmetic, and can also be 6.0% by mass or less, 5.5% by mass or less, 5.0% by mass or less, 4.5% by mass or less, or 4.0% by mass or less, relative to the total amount of the emulsified cosmetic. In the case of oil-in-water emulsified cosmetic, the amount of polyvinyl alcohol is preferably 2.5% by mass or more.

[0049] (oil drop) In oil-in-water emulsion cosmetics, the oil droplets, which are the oil phase or dispersed phase, contain oil and, typically, a surfactant.

[0050] C.Oil content There are no particular restrictions on the oils that can be used in the oil-in-water emulsion cosmetic composition of this disclosure, and volatile oils and / or non-volatile oils can be used, however, from the viewpoint of humidity responsiveness, it is preferable that the oils include non-volatile oils. Specifically, examples include non-polar oils (e.g., non-polar hydrocarbon oils) and polar oils. The oils can be used alone or in combination of two or more types. Among these, from the viewpoint of humidity responsiveness, non-polar hydrocarbon oils are preferred, and non-volatile non-polar hydrocarbon oils are more preferred. Here, "non-volatile" means that the volatile content after being left at atmospheric pressure and 105°C for 3 hours is 5% or less. In contrast, "volatile" means that the volatile content after being left at atmospheric pressure and 105°C for 3 hours is more than 5.0% by mass.

[0051] There are no particular restrictions on nonpolar hydrocarbon oils, and examples include petrolatum, liquid paraffin, tetraisobutane, hydrogenated polydecene, microcrystalline wax, olefin oligomers, isododecane, isohexadecane, squalane, polybutene, hydrogenated polybutene, polyisobutene, and hydrogenated polyisobutene. Nonpolar hydrocarbon oils can be used alone or in combination of two or more. Among these, petrolatum, microcrystalline wax, and olefin oligomers are preferred from the viewpoint of the overall humidity response of the area where the emulsified cosmetic is applied to the skin, and petrolatum is more preferred.

[0052] Other oil components besides nonpolar hydrocarbon oils include, but are not limited to, liquid oils and fats, solid oils and fats, waxes, silicone oils, and synthetic ester oils. These can be used individually or in combination of two or more.

[0053] Examples of liquid oils include avocado oil, camellia oil, turtle oil, macadamia nut oil, corn oil, mink oil, olive oil, rapeseed oil, egg yolk oil, sesame oil, peach kernel oil, wheat germ oil, sasanqua oil, castor oil, linseed oil, safflower oil, cottonseed oil, elm oil, soybean oil, peanut oil, tea seed oil, kaya oil, rice bran oil, cinnamon oil, Japanese tuni oil, jojoba oil, wheat germ oil, and triglycerin.

[0054] Examples of solid fats and oils include cocoa butter, coconut oil, horse fat, hydrogenated coconut oil, palm oil, beef tallow, sheep fat, hydrogenated beef tallow, palm kernel oil, pork fat, beef bone fat, Japanese wax kernel oil, hydrogenated oil, beef foot tallow, Japanese wax, and hydrogenated castor oil.

[0055] Examples of waxes include beeswax, candelilla wax, cotton wax, carnauba wax, bayberry wax, privet wax, whale wax, montan wax, rice bran wax, lanolin, kapok wax, lanolin acetate, liquid lanolin, sugarcane wax, isopropyl lanolin fatty acid, hexyl laurate, reduced lanolin, jojoba wax, hard lanolin, shellac wax, POE lanolin alcohol ether, POE lanolin alcohol acetate, POE cholesterol ether, lanolin fatty acid polyethylene glycol, and POE hydrogenated lanolin alcohol ether.

[0056] Examples of silicone oils include linear silicones such as dimethylpolysiloxane (dimethicone), methylphenylpolysiloxane, and methylhydrogenpolysiloxane; and cyclic silicones such as octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecamethylcyclohexasiloxane.

[0057] Examples of synthetic ester oils include isopropyl myristate, cetyl octanoate, octyldodecyl myristate, isopropyl palmitate, butyl stearate, hexyl laurate, myristyl myristate, decyl oleate, hexyldecyl dimethyloctanoate, cetyl lactate, myristyl lactate, lanolin acetate, isocetyl stearate, isocetyl isostearate, cholesteryl 12-hydroxystearate, ethylene glycol di-2-ethylhexanoate, dipentaerythritol fatty acid ester, N-alkyl glycol monoisostearate, neopentyl glycol dicaprate, diisostearyl malate, glyceryl di-2-heptylundecanoate, trimethylolpropane tri-2-ethylhexanoate, trimethylolpropane triisostearate, pentaerythritol tetra-2-ethylhexanoate Glyceryl tri-2-ethylhexanoate, glyceryl trioctanoate, glyceryl triisopalmitate, trimethylolpropane triisostearate, cetyl 2-ethylhexanoate, 2-ethylhexyl palmitate, glyceryl trimyristate, glyceride tri-2-heptylundecanoate, methyl castor oil fatty acid ester, oleyl oleate, acetoglyceride, 2-heptyl palmitate Examples include undecyl, diisobutyl adipate, 2-octyldodecyl N-lauroyl-L-glutamate, di-2-heptylundecyl adipate, ethyl laurate, di-2-ethylhexyl sebacate, 2-hexyldecyl myristate, 2-hexyldecyl palmitate, 2-hexyldecyl adipate, diisopropyl sebacate, 2-ethylhexyl succinate, and triethyl citrate.

[0058] Such synthetic ester oils are classified as polar oils. Polar oils and non-polar oils can be distinguished by their IOB value. The IOB value of polar oils can be, for example, 0.10 or higher, 0.11 or higher, 0.12 or higher, or 0.13 or higher, and can also be 0.50 or lower, 0.45 or lower, or 0.40 or lower. Here, the IOB value is an abbreviation for Inorganic / Organic Balance, and it is a value that represents the ratio of the inorganic value to the organic value, and serves as an indicator of the degree of polarity of an organic compound. Specifically, the IOB value is expressed as IOB value = inorganic value / organic value. For each of the "inorganic value" and "organic value," for example, one carbon atom in a molecule has an "organic value" of 20, and one hydroxyl group has an "inorganic value" of 100. These values ​​are assigned according to the type of atom or functional group, and the IOB value of an organic compound can be calculated by summing the "inorganic value" and "organic value" of all atoms and functional groups in the organic compound (see, for example, Yoshio Koda, "Organic Concept Diagram - Fundamentals and Applications," pp. 11-17, Sankyo Publishing, 1984).

[0059] In this disclosure, UV absorbers with an IOB of 0.10 or higher can be considered polar oils. Examples of UV absorbers that satisfy this condition include, for example, organic UV absorbers such as octyl methoxycinnamate (ethylhexyl methoxycinnamate), octocrylene, polysilicone-15, t-butyl methoxydibenzoylmethane, ethylhexyl triazone, bis-ethylhexyloxyphenol methoxyphenyl triazine, diethylamino hydroxybenzoyl hexyl benzoate, oxybenzone-3, methylenebisbenzotriazolyltetramethylbutylphenol, homosalate, and ethylhexyl salicylate. These UV absorbers can be used individually or in combination of two or more.

[0060] There are no particular restrictions on the oil content in the oil-in-water emulsion cosmetic composition of this disclosure. For example, the oil content may be 1% by mass or more, 3% by mass or more, 5% by mass or more, 7% by mass or more, 10% by mass or more, 13% by mass or more, or 15% by mass or more, relative to the total amount of the emulsion cosmetic composition. It may also be 50% by mass or less, 40% by mass or less, 30% by mass or less, 25% by mass or less, or 20% by mass or less.

[0061] When the oil component includes non-volatile oil, the proportion of non-volatile oil in the oil component can be, for example, 10% by mass or more, 20% by mass or more, 30% by mass or more, 35% by mass or more, 40% by mass or more, 45% by mass or more, or 50% by mass or more, and can also be 100% by mass or less, less than 100% by mass, 95% by mass or less, 90% by mass or less, 85% by mass or less, 80% by mass or less, 75% by mass or less, or 70% by mass or less.

[0062] The oil in the emulsified cosmetic may remain on the skin along with the PVA after the emulsified cosmetic has been applied to the skin and the water has evaporated, as shown in Figure 1 or Figure 3. Among oils, polar oils and silicone oils have a higher water permeability than non-polar hydrocarbon oils. As a result, if polar oils and silicone oils are present in high concentrations in the oil, water may pass through the oil without going through the PVA layer or PVA particles even in low humidity environments, which may result in poor humidity response. On the other hand, non-polar hydrocarbons have moderate waterproofing and moisture permeability compared to polar oils and silicone oils. Therefore, from the viewpoint of obtaining good humidity response in the area where the emulsified cosmetic is applied to the skin, it is preferable that the oil contains non-polar hydrocarbon oils. The proportion of nonpolar hydrocarbon oil in the oil, preferably the proportion of nonpolar hydrocarbon oil in the nonvolatile oil, is preferably 10% by mass or more, 15% by mass or more, 20% by mass or more, 25% by mass or more, 30% by mass or more, 35% by mass or more, or 40% by mass or more, and also preferably 90% by mass or less, 85% by mass or less, 80% by mass or less, 75% by mass or less, 70% by mass or less, 65% by mass or less, 60% by mass or less, 55% by mass or less, 50% by mass or less, 45% by mass or less, or 40% by mass or less.

[0063] Furthermore, from the viewpoint of obtaining good humidity response in the area where the emulsified cosmetic is applied to the skin, the mass ratio of polyvinyl alcohol to nonpolar hydrocarbon oil (PVA / nonpolar hydrocarbon oil) is preferably 0.01 or higher, 0.03 or higher, 0.05 or higher, 0.07 or higher, 0.10 or higher, 0.15 or higher, 0.20 or higher, 0.25 or higher, or 0.30 or higher. There is no particular upper limit to such a mass ratio; for example, it can be 1.0 or lower, 0.80 or lower, 0.60 or lower, 0.50 or lower, or 0.40 or lower.

[0064] The overall humidity response of the area where the emulsified cosmetic is applied to the skin may be influenced by the balance between the PVA layer or PVA particles and the remaining oil. The desired humidity response can be obtained by appropriately adjusting the mass ratio of polyvinyl alcohol to the remaining oil (non-volatile oil) when the emulsified cosmetic is applied to the skin. For example, such a mass ratio (PVA / non-volatile oil) can be 0.01 or higher, 0.03 or higher, 0.05 or higher, 0.07 or higher, 0.10 or higher, 0.15 or higher, 0.20 or higher, 0.25 or higher, 0.30 or higher, 0.35 or higher, 0.40 or higher, 0.45 or higher, 0.50 or higher, 0.55 or higher, 0.60 or higher, 0.65 or higher, or 0.70 or higher, and can also be 1.5 or lower, 1.3 or lower, 1.0 or lower, 0.90 or lower, 0.80 or lower, or 0.70 or lower. In the case of oil-in-water emulsion cosmetics, such a mass ratio is particularly preferable to be 0.60 or higher.

[0065] As described above, polar oils and silicone oils have a higher ability to permeate moisture compared to non-polar hydrocarbon oils. Therefore, the overall humidity response of the area where the emulsified cosmetic is applied to the skin may be influenced by the balance between the PVA layer or PVA particles and the remaining polar oil and / or silicone oil. The desired humidity response can be obtained by appropriately adjusting the mass ratio of polyvinyl alcohol to the remaining polar oil or silicone oil (non-volatile polar oil and silicone oil) when the emulsified cosmetic is applied to the skin. For example, the mass ratio (PVA / non-volatile polar oil, or PVA / non-volatile silicone oil) can be independently 0.01 or higher, 0.05 or higher, 0.10 or higher, 0.20 or higher, 0.30 or higher, 0.40 or higher, 0.50 or higher, 0.60 or higher, 0.70 or higher, 0.80 or higher, 0.90 or higher, or 1.0 or higher, and can also be 7.0 or lower, 6.5 or lower, 6.0 or lower, 5.5 or lower, 5.0 or lower, 4.5 or lower, 4.0 or lower, 3.5 or lower, 3.0 or lower, 2.5 or lower, 2.0 or lower, 1.5 or lower, or 1.0 or lower. In the case of oil-in-water emulsion cosmetics, the mass ratio of PVA / polar oil is preferably 0.25 or higher, and the mass ratio of PVA / silicone oil is preferably 0.90 or higher.

[0066] D. Surfactants (emulsifiers) There are no particular limitations on the surfactants that can be used in the oil-in-water emulsion cosmetic composition of this disclosure, and examples include ionic surfactants and nonionic surfactants. Surfactants can be used alone or in combination of two or more types.

[0067] There are no particular restrictions on the ionic surfactant used; anionic, cationic, or amphoteric ionic surfactants can be used. Among these, anionic surfactants are preferred from the viewpoint of emulsification stability, etc.

[0068] The anionic surfactant is not limited to the following, but at least one selected from carboxylate salts, sulfonates, sulfates, and phosphates can be used. The salt form is not particularly limited, but examples include alkali metal salts such as sodium salts, potassium salts, and lithium salts, alkaline earth metal salts such as magnesium salts and calcium salts, ammonium salts, and amino acid salts.

[0069] The nonionic surfactant is not limited to the following, but for example, at least one of polyoxyethylene alkyl ether, polyglycerin fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene lanolin / lanolin alcohol / beeswax derivative, polyoxyethylene castor oil / hydrogenated castor oil, polyoxyethylene sterol / hydrogenated sterol, polyethylene glycol fatty acid ester, and polyoxyethylene glyceryl isostearate can be used. Among these, the use of polyoxyethylene alkyl ether is preferred.

[0070] There are no particular restrictions on the surfactant content in oil-in-water emulsion cosmetics. For example, it can be 0.1% by mass or more, 0.3% by mass or more, or 0.5% by mass or more, relative to the total amount of the emulsion cosmetic, or it can be 5.0% by mass or less, 4.0% by mass or less, 3.0% by mass or less, or 2.0% by mass or less.

[0071] <Water-in-oil emulsion cosmetic> The water-in-oil emulsion cosmetic composition of this disclosure comprises, as the oil phase, a dispersion medium containing oil, and as the aqueous phase, water droplets dispersed in the dispersion medium, wherein the water droplets contain water, polyvinyl alcohol, and typically a surfactant, and the polyvinyl alcohol content is 0.5% by mass or more based on the total amount of the emulsion cosmetic composition.

[0072] As mentioned above, such water-in-oil emulsion cosmetics can exhibit humidity responsiveness at the application site when applied to the body surface.

[0073] In the water-in-oil emulsion cosmetic, the water, polyvinyl alcohol, surfactant, and oil components that can be used are the same as those used in the oil-in-water emulsion cosmetic described above.

[0074] There are no particular restrictions on the water content in water-in-oil emulsion cosmetics. For example, the water content can be 1% by mass or more, 5% by mass or more, 10% by mass or more, 15% by mass or more, or 20% by mass or more, relative to the total amount of the emulsion cosmetic. It can also be 50% by mass or less, 40% by mass or less, 30% by mass or less, 25% by mass or less, or 20% by mass or less.

[0075] The polyvinyl alcohol content in a water-in-oil emulsion cosmetic can be 0.7% by mass or more, 1.0% by mass or more, 1.5% by mass or more, 2.0% by mass or more, 2.5% by mass or more, 3.0% by mass or more, 3.5% by mass or more, or 4.0% by mass or more, from the viewpoint of humidity response, application performance, etc., and can also be 6.0% by mass or less, 5.5% by mass or less, 5.0% by mass or less, 4.5% by mass or less, or 4.0% by mass or less. For example, in the case of a water-in-oil emulsion cosmetic containing powder such as inorganic particles as an optional component, the amount of polyvinyl alcohol blended is preferably 5.0% by mass or less from the viewpoint of suppressing powder aggregation.

[0076] There are no particular restrictions on the surfactant content in water-in-oil emulsion cosmetics. For example, it can be 0.1% by mass or more, 0.3% by mass or more, or 0.5% by mass or more, relative to the total amount of the emulsion cosmetic, or it can be 5.0% by mass or less, 4.0% by mass or less, 3.0% by mass or less, or 2.0% by mass or less.

[0077] There are no particular restrictions on the oil content in water-in-oil emulsion cosmetics. For example, from the viewpoint of emulsification stability, the oil content can be 15% by mass or more, 20% by mass or more, 25% by mass or more, 30% by mass or more, 35% by mass or more, or 40% by mass or more, relative to the total amount of the emulsion cosmetic, or it can be 90% by mass or less, 80% by mass or less, 70% by mass or less, 60% by mass or less, or 50% by mass or less.

[0078] When the oil component includes non-volatile oil, the proportion of non-volatile oil in the oil component can be, for example, 10% by mass or more, 20% by mass or more, 30% by mass or more, 35% by mass or more, 40% by mass or more, 45% by mass or more, or 50% by mass or more, and can also be 100% by mass or less, less than 100% by mass, 95% by mass or less, 90% by mass or less, 85% by mass or less, 80% by mass or less, 75% by mass or less, or 70% by mass or less.

[0079] Similar to oil-in-water emulsion cosmetics, it is preferable that the oil component contains nonpolar hydrocarbon oil from the viewpoint of obtaining good humidity response at the site where the water-in-oil emulsion cosmetic is applied to the skin. The proportion of nonpolar hydrocarbon oil in the oil component, preferably the proportion of nonpolar hydrocarbon oil in the nonvolatile oil, is preferably 10% by mass or more, 15% by mass or more, 20% by mass or more, 25% by mass or more, 30% by mass or more, 35% by mass or more, 40% by mass or more, 45% by mass or more, or 50% by mass or more, and also preferably 90% by mass or less, 85% by mass or less, 80% by mass or less, 75% by mass or less, 70% by mass or less, 65% by mass or less, 60% by mass or less, 55% by mass or less, or 50% by mass or less.

[0080] Furthermore, from the viewpoint of obtaining good humidity response in the area where the emulsified cosmetic is applied to the skin, the mass ratio of polyvinyl alcohol to nonpolar hydrocarbon oil (PVA / nonpolar hydrocarbon oil) is preferably 0.01 or higher, 0.03 or higher, 0.05 or higher, 0.07 or higher, 0.10 or higher, 0.15 or higher, 0.20 or higher, 0.25 or higher, or 0.30 or higher. There is no particular upper limit to such a mass ratio; for example, it can be 1.0 or lower, 0.80 or lower, 0.60 or lower, 0.50 or lower, or 0.40 or lower. In the case of water-in-oil emulsified cosmetic, such a mass ratio is preferably 0.03 or higher.

[0081] Similar to oil-in-water emulsions, the overall humidity response of a site where an oil-in-oil emulsion is applied to the skin may be influenced by the balance between the PVA layer or PVA particles and the remaining oil. The desired humidity response can be obtained by appropriately adjusting the mass ratio of polyvinyl alcohol to the remaining oil (non-volatile oil) when the emulsion is applied to the skin. For example, such a mass ratio (PVA / non-volatile oil) can be 0.01 or higher, 0.03 or higher, 0.05 or higher, 0.07 or higher, 0.10 or higher, 0.15 or higher, 0.20 or higher, 0.25 or higher, 0.30 or higher, 0.35 or higher, 0.40 or higher, 0.45 or higher, 0.50 or higher, 0.55 or higher, 0.60 or higher, 0.65 or higher, or 0.70 or higher, and can also be 1.5 or lower, 1.3 or lower, 1.0 or lower, 0.90 or lower, 0.80 or lower, or 0.70 or lower. In the case of water-in-oil emulsion cosmetics, such a mass ratio is particularly preferable to be 0.03 or higher.

[0082] As described above, polar oils and silicone oils have a higher ability to permeate moisture compared to non-polar hydrocarbon oils. Therefore, the overall humidity response of the area where a water-in-oil emulsion cosmetic is applied to the skin may be influenced by the balance between the PVA layer or PVA particles and the remaining polar oil and / or silicone oil. The desired humidity response can be obtained by appropriately adjusting the mass ratio of polyvinyl alcohol to the remaining polar oil or silicone oil (non-volatile polar oil and silicone oil) when the emulsion cosmetic is applied to the skin. For example, the mass ratio (PVA / non-volatile polar oil or PVA / non-volatile silicone oil) can be independently 0.01 or higher, 0.05 or higher, 0.10 or higher, 0.20 or higher, 0.30 or higher, 0.40 or higher, 0.50 or higher, 0.60 or higher, 0.70 or higher, 0.80 or higher, 0.90 or higher, or 1.0 or higher, and can also be 7.0 or lower, 6.5 or lower, 6.0 or lower, 5.5 or lower, 5.0 or lower, 4.5 or lower, 4.0 or lower, 3.5 or lower, 3.0 or lower, 2.5 or lower, 2.0 or lower, 1.5 or lower, or 1.0 or lower. In the case of water-in-oil emulsion cosmetics, the mass ratio of PVA / polar oil is preferably 0.05 or higher, and the mass ratio of PVA / silicone oil is preferably 0.05 or higher.

[0083] <Amount of emulsified cosmetic to be used> There are no particular restrictions on the amount of the emulsified cosmetic composition of this disclosure that can be applied to the skin, and it can be adjusted as appropriate to obtain the desired humidity response.

[0084] <Optional ingredients> In addition to the various components described above, the emulsified cosmetic composition of this disclosure (oil-in-water emulsion cosmetic composition or water-in-oil emulsion cosmetic composition) may contain various additive components that are commonly used in cosmetics, to the extent that they do not affect the effects of the present invention. For example, the following can be used: humectants such as 1,3-butylene glycol, propylene glycol, and dynamite glycerin; film-forming agents such as water-soluble polymers, oil-soluble polymers, and silicone polysaccharides; metal ion chelating agents; neutralizing agents; lower alcohols such as ethanol; polyhydric alcohols such as PEG6000 and dipropylene glycol; higher alcohols such as batyl alcohol; various extracts; sugars; amino acids; organic amines; polymer emulsions; chelating agents; other UV absorbers besides the UV absorbers mentioned above; UV scattering agents such as titanium dioxide; pH adjusters; skin nutrients; vitamins; water-soluble agents applicable to pharmaceuticals, quasi-drugs, cosmetics, etc.; antioxidants; buffers; preservatives; antioxidant aids; thickeners; dispersants; propellants; usable powders; pigments; pearlescent agents; dyes; colorants; fragrances; acidic components; and alkaline components. These optional components can be used individually or in combination of two or more, and can be appropriately blended in the oil phase or aqueous phase.

[0085] The emulsified cosmetic composition of this disclosure may contain various inorganic particles that can be used as ultraviolet scattering agents, usable powders, pigments, pearlescent agents, etc. From the viewpoint of suppressing the decrease in humidity responsiveness due to the PVA layer or PVA particles as shown in Figure 1 or Figure 3, it is preferable to incorporate the inorganic particles into the oil phase.

[0086] Inorganic particles typically have hydroxyl groups on their surface. Because these hydroxyl groups readily adhere to PVA, if inorganic particles are incorporated in high concentrations, PVA may be adsorbed and consumed by the inorganic particles, resulting in a lack of good humidity responsiveness. Therefore, the inorganic particle content is preferably 30% by mass or less, 25% by mass or less, 20% by mass or less, 15% by mass or less, 10% by mass or less, 8% by mass or less, 5% by mass or less, 3% by mass or less, 1% by mass or less, or 0.5% by mass or less, relative to the total amount of the emulsified cosmetic. With such a content, the emulsified cosmetic of this disclosure can provide good humidity responsiveness while imparting various properties based on the inorganic particles.

[0087] Dosage Forms and Product Forms of Emulsified Cosmetics The dosage form of the emulsified cosmetic composition of this disclosure is not particularly limited and includes, for example, liquid, lotion, cream, gel, mist, spray, aerosol, mousse, etc. The product form of the emulsified cosmetic composition of this disclosure is also not particularly limited and includes, for example, skincare cosmetics such as lotions, creams, face oils, body oils, and serums; makeup cosmetics such as foundations, makeup bases, lipsticks, blushes, eyeshadows, mascaras, and mascara primers; and sunscreen cosmetics. In particular, it is advantageous to use it as a makeup base to be used before foundation.

[0088] Method for manufacturing emulsified cosmetics The emulsified cosmetic composition of this disclosure can be prepared by known methods such as dispersion methods and aggregation methods.

[0089] Dispersion methods are techniques for breaking down clumps of a dispersed phase into smaller particles using mechanical force. Specifically, they involve emulsifying using the crushing force of an emulsifier. Examples of such methods include high-pressure emulsification, which applies high shear force using a high-pressure homogenizer.

[0090] The agglomeration method is a colloid preparation method that utilizes interfacial chemical properties. It involves creating a supersaturated state from a uniformly dissolved state by some means, thereby introducing a dispersed phase. Specific methods include HLB temperature emulsification, phase inversion emulsification, non-aqueous emulsification, D-phase emulsification, and liquid crystal emulsification.

[0091] Beauty methods using emulsified cosmetics The cosmetic method using the emulsified cosmetic of this disclosure includes applying the emulsified cosmetic to the body surface. When applied to the skin, the emulsified cosmetic of this disclosure can reduce or suppress the evaporation of moisture from the skin in a low-humidity environment, and can adequately moisturize the skin even in a low-humidity environment. As a result, the skin's own ability to produce moisturizing components is improved, and the abnormalities in turnover in the stratum corneum are also improved, making skin problems such as rough skin less likely to occur and enhancing the cosmetic effect.

[0092] There are no particular restrictions on the means of applying emulsified cosmetics to the body surface; for example, it can be done by applying the emulsified cosmetics to the body surface. As a means of applying emulsified cosmetics to the body surface, for example, the cosmetics may be sprayed onto the skin from a spray container containing the cosmetics, or the cosmetics may be placed in a container without a spray function, an appropriate amount of cosmetics may be taken from such a container with a finger or the like, and then spread onto the body surface.

[0093] Areas where emulsified cosmetics can be applied The emulsified cosmetic composition of this disclosure can be applied to any part of the skin surface of the body, i.e., any part of the body surface. For example, it can be applied as appropriate to the skin surface of the face (lips, eyes, nose, cheeks, forehead, etc.), neck, ears, hands, arms, legs, feet, chest, abdomen, back, etc. Here, skin includes nails, which are formed by the hardening of the keratinized layer of the epidermis. [Examples]

[0094] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0095] Examples 1-5 and Comparative Examples 1-2: Oil-in-Water Emulsified Cosmetics (Cream Type) Oil-in-water emulsion cosmetics were prepared using the formulations shown in Table 1 by conventional methods. These were evaluated for humidity responsiveness using the water evaporation test 1 described below. The results are shown in Table 1. Note that the test sample for Comparative Example 1 was prepared by applying only filter paper to the open end of a vial containing 20 mL of water.

[0096] <Evaluation Method> (Moisture evaporation test 1: Humidity responsiveness) Opening of a vial containing 20 mL of water (area: 0.000177 m²) 2 ) filter paper (ADVANTEC, #133, basis weight 14 mg / cm²) 2 The vial was covered with a filter paper, and the emulsified cosmetic was applied to the entire surface of the filter paper. The vial was then placed in a constant temperature bath under specified temperature and humidity conditions. After standing for approximately 2-3 days until the evaporation rate became nearly constant with respect to time, the amount of water lost in the vial was measured, and the water evaporation rate (g / hour), which is the amount of water lost per unit area and per unit time, was calculated. The test was conducted in two environments: a low humidity environment of 28°C and 20%RH, and a high humidity environment of 28°C and 80%RH. Next, the permeability coefficient was calculated using the water evaporation rates obtained under each condition from the following equation 2: Permeability coefficient (mol·m / m 2 (s·Pa) = [{(Moisture evaporation rate (g / hour) at 28℃ and specified humidity / 18 / 3600 / Permeable area (m²) 2 )} / (Water vapor pressure at 28°C and 100%RH (Pa) - Water vapor pressure at 28°C and specified humidity (Pa))] × Film thickness of filter paper (m) ... Equation 2

[0097] Here, in Equation 1, the permeable area is 0.000177 m². 2 The water vapor pressure (Pa) at 28°C and 20%RH is 756.2 Pa, the water vapor pressure (Pa) at 28°C and 80%RH is 3024.7 Pa, and the water vapor pressure (Pa) at 28°C and 100%RH is 3780.9 Pa. The film thickness of the filter paper is 0.000175 m.

[0098] Based on the obtained transmission coefficient, the humidity responsiveness was evaluated according to the following criteria. Here, a rating of C can be considered a failure: A: The transmittance coefficient under low humidity conditions was significantly lower than that under high humidity conditions, indicating good humidity responsiveness. B: The transmittance coefficient under low humidity conditions was slightly lower than that under high humidity conditions, indicating humidity responsiveness at a good quality level. C: The transmittance coefficient under low humidity conditions was equal to or greater than that under high humidity conditions, indicating no humidity responsiveness.

[0099] [Table 1]

[0100] <result> As is clear from the results in Table 1, it was confirmed that oil-in-water emulsion cosmetics containing a predetermined amount of polyvinyl alcohol exhibited humidity responsiveness when applied to the skin. Furthermore, it was found that humidity responsiveness improved as the amount of polyvinyl alcohol increased.

[0101] Examples 6-9 and Comparative Example 3: Water-in-Oil Emulsified Cosmetics Using the formulations shown in Table 2, water-in-oil emulsion cosmetics were prepared by conventional methods. These were then evaluated as described above, and the results are shown in Table 2.

[0102] [Table 2]

[0103] <result> As is clear from the results in Table 2, it was confirmed that water-in-oil emulsion cosmetics containing a predetermined amount of polyvinyl alcohol exhibit humidity responsiveness when applied to the skin. Furthermore, compared to the results in Table 1, it was found that water-in-oil emulsion cosmetics can exhibit good humidity responsiveness even at a low amount of polyvinyl alcohol.

[0104] Examples 10-17 and Comparative Example 4: Water-in-Oil Emulsified Cosmetics Using the formulations shown in Table 3, water-in-oil emulsion cosmetics were prepared by conventional methods. These were then evaluated as described above, and the results are shown in Table 3.

[0105]

Table 3

[0106] 〈Results〉 From the results in Table 3, it was confirmed that not only titanium oxide and zinc oxide but also when inorganic particles such as silica and mica are included, good humidity responsiveness can be exhibited if a predetermined amount of polyvinyl alcohol is contained.

[0107] 《Examples 18 to 23 and Comparative Example 5: Water-in-oil type emulsified cosmetics (cream-like)》 Using the formulations shown in Table 4, water-in-oil type emulsified cosmetics were each prepared by a conventional method. For these, the above evaluations were carried out, and the results are shown in Table 4.

[0108]

Table 4

[0109] 〈Results〉 As is clear from comparing Examples 18 to 21 and Examples 22 to 23 in Table 4, it was confirmed that when non-polar hydrocarbon oil was contained in the oil component, it was superior in humidity responsiveness.

[0110] 《Reference Examples 1 to 3 and Reference Comparative Examples 1 to 2: Polyvinyl alcohol films》 For reference, for self-standing polyvinyl alcohol films such as wrap films obtained by the production methods described in Reference Examples 1 to 3, as well as filter paper (Reference Comparative Example 1) and polylactic acid films (Reference Comparative Example 2), evaluations regarding humidity responsiveness were carried out by the following Moisture Transpiration Test 2. The results are shown in Table 5. Incidentally, as a reference example, the results of the open-system samples are shown in Table 5.

[0111] 〈Evaluation method〉 (Moisture Transpiration Test 2: Humidity responsiveness) The circular opening part (radius: 0.7 cm, area: 1.54 cm 2Each vial was sealed with a sample for measurement, and the vials were placed in a constant temperature bath under specified temperature and humidity conditions. After standing for approximately 2-3 days until the evaporation rate became nearly constant with respect to time, the amount of water lost in the vials was measured, and the amount of water lost per unit area and per unit time was calculated. The test was conducted in two environments: a low humidity environment of 23°C and 40%RH, and a high humidity environment of 28°C and 70%RH.

[0112] <Reference Example 1> A composition for polyvinyl alcohol film production was prepared by mixing unmodified, fully saponified polyvinyl alcohol, KURARAY POVAL® PVA-117H (manufactured by Kuraray Co., Ltd.), and deionized water in a 10 mL vial and stirring to achieve a polyvinyl alcohol concentration of 5.0% by mass. Next, the resulting 5.0% by mass aqueous solution was used to create a film with an area of ​​19.6 cm². 2 3.0 g was added to a roughly circular petri dish and dried to obtain a sample for measurement, with a thickness of approximately 60 μm and a basis weight of approximately 7.6 mg / cm². 2 A polyvinyl alcohol film was fabricated.

[0113] <Reference Example 2> A polyvinyl alcohol film for measurement was prepared in the same manner as in Reference Example 1, except that the concentration of polyvinyl alcohol was changed to 1.0% by mass. The resulting film had a thickness of approximately 10 μm and a basis weight of approximately 1.5 mg / cm². 2 That was the case.

[0114] <Reference Example 3> A polyvinyl alcohol film, which served as the measurement sample, was prepared in the same manner as in Reference Example 1, except that the concentration of polyvinyl alcohol was changed to 0.5% by mass. The resulting film had a thickness of approximately 6 μm and a basis weight of approximately 0.76 mg / cm². 2 That was the case.

[0115] <Reference Comparison Example 1> Thickness 250 μm, basis weight 14 mg / cm² 2ADVANTEC filter paper #133 was used as the measurement sample for Reference Comparative Example 1.

[0116] <Reference Comparison Example 2> Using a 0.1% by mass polylactic acid solution prepared with tetrahydrofuran, a thickness of approximately 200 nm and a basis weight of approximately 0.025 mg / cm² were achieved by spin coating. 2 A polylactic acid film was prepared. Two of these polylactic acid films were layered together and used as the measurement sample for Reference Comparative Example 2.

[0117] <Reference example 1> As a reference example, we used an open-type sample in a vial bottle without a cap on the opening.

[0118] [Table 5]

[0119] <result> As shown in Table 5, the filter paper of Reference Comparative Example 1 and the polylactic acid film of Reference Comparative Example 2 showed that the amount of water evaporation was greater in low-humidity environments than in high-humidity environments, and therefore did not exhibit humidity responsiveness. On the other hand, the polyvinyl alcohol films of Reference Examples 1 to 3 showed that the amount of water evaporation in low-humidity environments was significantly lower than the amount of water evaporation in high-humidity environments, confirming that they exhibit humidity responsiveness.

[0120] Reference Examples 4-5 and Reference Comparative Example 3 We evaluated the amount of water evaporation from human skin, and the results are summarized in Table 6. Here, we measured the amount of water evaporation using a VAPO METER manufactured by Keystone Corporation under two environmental conditions: a low humidity environment of 23°C and 40%RH, and a high humidity environment of 28°C and 70%RH.

[0121] <Reference Example 4> The polyvinyl alcohol film (approximately 10 μm thick) obtained in Reference Example 2 was laminated to the skin surface on the inside of a human left arm.

[0122] <Reference Example 5> Approximately 1.5 mg / cm³ of petrolatum (Sunwhite P-1, manufactured by Nikko Rica Co., Ltd.) was applied to the skin surface on the inner side of a human left arm. 2 The mixture was applied in the specified proportions to form a waterproof and breathable layer corresponding to the oil layer 109 shown in Figure 1, and a polyvinyl alcohol film (approximately 10 μm thick) obtained in Reference Example 2 was laminated on top of it. This configuration corresponds to the two-layer configuration shown in Figure 1.

[0123] <Reference Comparison Example 3> The amount of moisture lost from bare skin was measured.

[0124] [Table 6]

[0125] <result> As shown in the results in Table 6, the amount of moisture evaporation from bare skin was greater in low humidity environments than in high humidity environments. On the other hand, in Reference Examples 4 and 5, which used polyvinyl alcohol film, no sticky or unpleasant feeling was observed in high humidity environments, and the amount of moisture evaporation in low humidity environments was kept lower than that in high humidity environments, confirming that the moisturizing performance of the skin in low humidity environments can be improved. Since the emulsified cosmetic composition of this disclosure is thought to exhibit a similar composition to that of Reference Example 5 when applied to the skin, it is expected that the same effects will be exhibited in the emulsified cosmetic composition of this disclosure. It should be noted that in high humidity environments, the amount of moisture evaporation in Reference Example 4 was greater than that of Reference Comparative Example 3. This is thought to be because the measurement points on the bare skin in Reference Comparative Example 3 and the areas where the PVA film was applied to the bare skin in Reference Example 4 were different, meaning that the amount of moisture evaporation from the bare skin at each measurement point was different.

[0126] Examples of emulsified cosmetic formulations Examples of formulations for emulsified cosmetics according to this disclosure are given below, but are not limited to these examples. The facial gels in the following formulation examples exhibited good humidity responsiveness.

[0127] (Example formulation: Facial gel (water-in-oil emulsion composition)) Ingredients Amount (mass%) (1) 95% ethanol 3 (2) Dynamite Glycerin 15 (3) Dipropylene glycol 4 (4) Xylitol 2 (5) Polyvinyl alcohol 4 (6) Polyether-modified silicone 2 (7) Dimethicone (1.5CS) 10 (8) (Dimethicone / Vinyl Dimethicone) Crosspolymer 7 (9) Fine particle silica 5 (10) Preservatives: appropriate amount (11) Chelating agent: appropriate amount (12) Water residual Total 100

[0128] (Method of manufacturing facial gel) In the above composition, the aqueous phase components (1) to (5) and (10) to (12), and the oil phase components (6) to (9) were stirred and mixed to prepare a uniform aqueous phase and an oil phase. Next, the aqueous phase was added to the oil phase while stirring and mixed to prepare a water-in-oil emulsion composition for face. [Explanation of Symbols]

[0129] 100, 200 First composition 300, 400 Second composition 101, 201 Polyvinyl alcohol layer 301, 401 Polyvinyl alcohol particles 103, 203, 303, 403 Polyvinyl alcohol molecules 105, 205, 305, 405 Moisture 107, 207 Moisture-permeable gaps 307, 407 Passages that can allow moisture to pass through 108, 208 Water passing through the oil layer 109, 209 oil layer 309, 409 Oil layer containing polyvinyl alcohol particles

Claims

1. Water, and an aqueous phase containing polyvinyl alcohol, An emulsified cosmetic composition comprising an oil phase containing oil, The polyvinyl alcohol content is 0.5% by mass or more relative to the total amount of the emulsified cosmetic composition. The oil component includes a non-volatile polar oil with an IOB value of 0.10 or higher, and a non-volatile silicone oil. The non-volatile silicone oil comprises at least one selected from the group consisting of dimethicone and caprylyl methicone. Emulsified cosmetic.

2. The cosmetic composition according to claim 1, wherein the polyvinyl alcohol content is 2.5% by mass or more relative to the total amount of the emulsified cosmetic composition.

3. The cosmetic composition according to claim 1 or 2, wherein the oil component includes a non-polar hydrocarbon oil.

4. The cosmetic composition according to claim 3, wherein the nonpolar hydrocarbon oil includes petrolatum.

5. The cosmetic composition according to claim 3 or 4, wherein the proportion of the nonpolar hydrocarbon oil in the oil is 10% by mass or more.

6. The cosmetic composition according to any one of claims 1 to 5, wherein the mass ratio of polyvinyl alcohol to the oil content remaining when the emulsified cosmetic composition is applied to the skin is 0.60 or more.

7. The cosmetic composition according to any one of claims 1 to 6, wherein the mass ratio of polyvinyl alcohol to the polar oil or silicone oil remaining when the emulsified cosmetic composition is applied to the skin is independently 0.01 or more.

8. A cosmetic composition according to any one of claims 1 to 7, further comprising inorganic particles.

9. The cosmetic composition according to claim 8, wherein the content of the inorganic particles is 10% by mass or less with respect to the total amount of the emulsified cosmetic composition.

10. The cosmetic composition according to any one of claims 1 to 9, wherein the emulsified cosmetic composition is an oil-in-water type or water-in-oil type emulsified cosmetic composition.

11. A cosmetic composition according to any one of claims 1 to 10, wherein, when evaluated by a moisture evaporation test, the moisture permeability coefficient measured under conditions of 23°C and 40% RH or 28°C and 20% RH is smaller than the moisture permeability coefficient measured under conditions of 28°C and 70% RH.

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