Oil-in-water emulsified cosmetic

Abstract

Provided is a novel oil-in-water emulsion cosmetic containing a hygroscopic aqueous compound, which is excellent in use properties and in which the tackiness and the like accompanying the hygroscopic aqueous compound are improved. The oil-in-water emulsion cosmetic of the present disclosure contains (a) a hygroscopic aqueous compound, (b) a polyglycerin fatty acid ester, (c) an oil component, and (d) water.

Description

Technical Field

[0001] This disclosure relates to water-in-oil emulsion cosmetics. Background Technology

[0002] In the field of cosmetics, water-in-oil emulsion cosmetics containing various surfactants and pharmaceuticals have been developed.

[0003] Patent document 1 discloses an oil-in-water emulsion cosmetic containing (A) a specific cyclic carboxamide derivative or its salt, (B) core-shell particles, (C) oil and (D) water, wherein (B) the core-shell particles are obtained by free radical polymerization of a polyoxyethylene macromonomer with a hydrophobic monomer selected from acrylic acid / methacrylic acid derivative monomers and acrylamide / methacrylamide derivative monomers.

[0004] Patent Document 2 discloses an oil-in-water emulsion cosmetic, which is an oil-in-water emulsion cosmetic containing an aqueous dispersion medium and oil droplets dispersed in the dispersion medium. The oil droplets contain oil and a disc-shaped structure. The disc-shaped structure is formed by stacking monolayers having hydrophilic and lipophilic portions, and is disposed at the interface with the aqueous phase in the oil droplet.

[0005] Patent document 3 discloses a water-in-oil emulsion cosmetic, which is a mixture of (a) a polysaccharide containing fucose and (b) a moisturizer.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: International Publication No. 2023 / 120180

[0009] Patent Document 2: International Publication No. 2022 / 234737

[0010] Patent Document 3: Japanese Patent Application Publication No. 11-269060 Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] As described in Patent Documents 1 and 3, cosmetics containing hygroscopic aqueous compounds such as cyclic carboxamide derivatives sometimes exhibit undesirable properties such as stickiness. To improve such undesirable properties, for example, a special material such as core-shell particles was used in Patent Document 1.

[0013] Therefore, the subject of this disclosure is to provide a novel oil-in-water emulsion cosmetic containing a hygroscopic aqueous compound that has improved the undesirable properties such as stickiness associated with hygroscopic aqueous compounds and has excellent usability.

[0014] Methods for solving problems

[0015] <Option 1>

[0016] A water-in-oil emulsion cosmetic, comprising

[0017] (a) Hygroscopic aqueous compounds, (b) Polyglycerol fatty acid esters (c) Oil, and (d) Water.

[0018] Option 2

[0019] According to the cosmetic material described in Scheme 1, the aforementioned (a) hygroscopic aqueous compound is a cyclic carboxamide derivative or a salt thereof as shown in Formula 1.

[0020] In Equation 1, R 1 It consists of a hydrocarbon group or hydrogen atom with 1 to 6 carbon atoms that can be replaced by a hydroxyl group. X is -CH2- or -N(R) 2 )-, where R 2 It consists of a hydrocarbon group or hydrogen atom with 1 to 6 carbon atoms that can be replaced by a hydroxyl group, and n is an integer from 1 to 3.

[0021] Option 3

[0022] According to Scheme 1 or 2, the content of the above-mentioned (a) hygroscopic aqueous compound is 5.0% by mass or less.

[0023] Option 4

[0024] In the cosmetic material according to any one of Schemes 1 to 3, the number of carbon atoms in the fatty acid portion of the polyglycerol fatty acid ester described above (b) is 12 or more and 14 or less.

[0025] Option 5

[0026] According to any one of Schemes 1 to 4, the polyglycerol portion of the polyglycerol fatty acid ester (b) is formed of polyglycerol with a 4-mer or more and a 8-mer or less.

[0027] <Option 6>

[0028] In the cosmetic material according to any one of Schemes 1 to 5, the content of the polyglycerol fatty acid ester (b) is 0.01% by mass or more and 1.5% by mass or less.

[0029] <Option 7>

[0030] A method for manufacturing an oil-in-water emulsion cosmetic according to any one of Schemes 1 to 6, the method comprising: A vesicle solution is formed by mixing the aqueous phase components comprising (a) the hygroscopic aqueous compound, (b) the polyglycerol fatty acid ester, and (d) the water described above; and An oil phase component containing the oil component (c) above is added to the above vesicle solution.

[0031] The effects of the invention

[0032] According to this disclosure, a novel oil-in-water emulsion cosmetic containing a hygroscopic aqueous compound can be provided, which improves the undesirable properties such as stickiness associated with hygroscopic aqueous compounds and has excellent usability. Attached Figure Description

[0033] Figure 1 This is a schematic diagram illustrating the configuration of a hygroscopic aqueous compound or the like in a water-in-oil emulsion cosmetic according to an embodiment of the present disclosure. Detailed Implementation

[0034] The embodiments of this disclosure will now be described in detail. This disclosure is not limited to the following embodiments, and various modifications can be made within the scope of the original intent of the invention.

[0035] The water-in-oil emulsion cosmetic disclosed herein comprises (a) a hygroscopic aqueous compound, (b) a polyglycerol fatty acid ester, (c) an oil component and (d) water.

[0036] Although not limited by principle, the working principle of the water-in-oil emulsion cosmetic disclosed herein, which improves the stickiness and other adverse conditions even when it contains hygroscopic aqueous compounds, is as follows.

[0037] Hygroscopic aqueous compounds, being water-based, are typically contained in the aqueous phase of oil-in-water emulsion cosmetics. Furthermore, considering that these hygroscopic aqueous compounds are contained in the aqueous phase, and that a portion of this compound usually also has a hydrophobic component, they tend to integrate easily in the aqueous phase. Moreover, if this integrated and enlarged hygroscopic aqueous compound is applied to the skin, it easily draws in surrounding moisture, potentially resulting in a sticky feeling.

[0038] The polyglycerol fatty acid ester used in the water-in-oil emulsion cosmetic of this disclosure has a polyglycerol portion, which can function as a surfactant. Considering that this polyglycerol portion has hydroxyl groups in the repeating units, it exhibits strong hydrophilicity, i.e., it has a tendency to readily bind to aqueous components. As a result, hygroscopic aqueous compounds in the aqueous phase are drawn to the polyglycerol portion of the polyglycerol fatty acid ester present at the interface between the oil droplets and the aqueous phase. Consequently, the integration of the hygroscopic aqueous compounds with each other is suppressed, and they are dispersed in the aqueous phase together with the oil droplets. Considering that the hygroscopic aqueous compounds in this state are smaller compared to the larger, integrated hygroscopic aqueous compounds, their ability to draw in surrounding moisture is poor, thus reducing the likelihood of undesirable conditions such as stickiness when the cosmetic is applied to the skin.

[0039] In some embodiments, polyglycerol fatty acid esters sometimes resemble Figure 1 As shown, the oil droplets are arranged in a disc-shaped structure to act as a surfactant. Since even in this case, the outermost layer contains a hydrophilic portion based on the polyglycerol portion, it is considered that the hygroscopic aqueous compound in the aqueous phase is not integrated into the aqueous phase, but rather... Figure 1 As shown, it exists in a state where the surface of the polyglycerol fatty acid ester surrounding the oil droplets is coated. As a result, the hygroscopic aqueous compound is not integrated, but dispersed in the aqueous phase together with the oil droplets. Furthermore, as mentioned above, since the hygroscopic aqueous compound in this state has a poor ability to attract surrounding moisture, undesirable conditions such as stickiness when applying cosmetics to the skin are less likely to occur.

[0040] Here, consider a disk-shaped structure such as Figure 1 As shown, vesicles formed in an aqueous phase disintegrate under the influence of oils, such as those in cosmetics. A portion of the monolayers constituting the vesicle's bilayer adsorbs onto the surface of the oil via its lipophilic (hydrophobic) portion. The bilayers of the vesicles are then stacked via the hydrophilic portions of these monolayers, or the monolayers constituting the vesicle's bilayer are stacked via either their hydrophilic or lipophilic portions, thereby forming a disc-shaped structure. Thus, the disc-shaped structure is formed from the monolayers of the vesicle's bilayer, each having both hydrophilic and lipophilic portions. As a result, the stacked disc-shaped structure, with its lipophilic (hydrophobic) portion at the oil droplet interface and its hydrophilic portion at the aqueous phase interface, can function as a whole, similar to a surfactant.

[0041] Monolayers formed from polyglycerol fatty acid esters having both hydrophilic and lipophilic portions also possess the ability to emulsify oils. Therefore, if this monolayer material is used as a surfactant to emulsify water and oil, the monolayer material, like a typical surfactant, is not layered but oriented near the interface between the oil droplet and the aqueous phase. However, in this state, the monolayer material generally does not remain near the interface between the oil droplet (emulsion particle) and the aqueous phase, but rather exists in an equilibrium state, for example, capable of moving into the aqueous phase or to the interface of other adjacent oil droplets.

[0042] On the other hand, considering that disc-shaped structures formed by stacking monolayers with hydrophilic and lipophilic portions are similar to vesicles, their movement in the aqueous phase or at the interface with adjacent oil droplets is reduced or inhibited compared to conventional surfactants. As a result, compared to using polyglycerol fatty acid esters as conventional surfactants, using them in the form of disc-shaped structures allows for the sustained retention of hygroscopic aqueous compounds and further inhibits their growth, thus further improving undesirable conditions such as stickiness when applying cosmetics to the skin.

[0043] Furthermore, Patent Document 2 describes an oil-in-water emulsion cosmetic containing a disc-shaped structure as an incidental effect of improved usability (tack resistance). However, this tack resistance is an improvement in tackiness associated with the oil component, not an improvement in tackiness associated with the hygroscopic aqueous compounds present in the aqueous phase. In other words, Patent Document 2 does not describe or suggest that an oil-in-water emulsion cosmetic containing a disc-shaped structure can also improve tackiness caused by tackiness components present in the aqueous phase.

[0044] The terms used in this disclosure are defined as follows.

[0045] In this disclosure, "disc-shaped structure" refers to a closed vesicle structure that does not form vesicles. Furthermore, the cross-sectional shape of this structure is as follows: Figure 1 The structure is a roughly plate-like shape (e.g., roughly square, roughly rectangular). The term "roughly" here means that the cross-sectional shape of the structure does not allow for a spherical shape like a vesicle, but allows for a certain degree of deformation, for example, deformation in a way that presents a curvature along the shape of an oil droplet.

[0046] The term "vesicle" in this disclosure also includes liposomes and polymeric vesicles.

[0047] The term "surfactant" in this disclosure also includes emulsifiers.

[0048] Water-in-oil emulsion cosmetics

[0049] <(a) Hygroscopic aqueous compounds>

[0050] The water-in-oil emulsion cosmetic (sometimes simply referred to as "cosmetic") disclosed herein contains a hygroscopic aqueous compound. The hygroscopic aqueous compound can be used alone or in combination of two or more.

[0051] There are no particular limitations on the mixing amount of the hygroscopic aqueous compound. For example, relative to the total amount of cosmetics, it can be 0.01% by mass or more, 0.05% by mass or more, 0.1% by mass or more, 0.5% by mass or more, or 1.0% by mass or more. As an upper limit for this mixing amount, for example, from the viewpoint of usability (resistance to stickiness), it is preferable to be 10% by mass or less, 7.0% by mass or less, or 5.0% by mass or less; more preferably, less than 5.0% by mass, 4.5% by mass or less, or 4.0% by mass or less; and particularly preferably, 3.5% by mass or less or 3.0% by mass or less. The hygroscopic aqueous compound can be appropriately used within such a range.

[0052] In this disclosure, "hygroscopic aqueous compound" refers to a compound that can dissolve or disperse in water and, for example, absorb or adsorb moisture in air under standard conditions (20°C, 1 atm, 65% humidity). Specifically, examples of such hygroscopic aqueous compounds include, for example, polyols containing hydroxyl groups, pyrrolidone carboxylates, lactates, dipotassium glycyrrhizate, and cyclic carboxamide derivatives or salts thereof as shown in Formula 1:

[0053] In Equation 1, R 1 A hydrocarbon group or hydrogen atom that can be replaced by a hydroxyl group having 1 or more, 2 or more, 6 or less, 5 or less, or 4 or less carbon atoms. X is -CH2- or -N(R) 2 )-, where R 2 It is a hydrocarbon group or hydrogen atom that can be replaced by a hydroxyl group, having 1 or more carbon atoms, or 2 or more, 6 or less, 5 or less, or 4 or less. n is an integer from 1 to 3.

[0054] The composition of the water-in-oil emulsion cosmetic disclosed herein can suitably act on the cyclic carboxamide derivative or its salt shown in Formula 1 above, improving undesirable conditions such as stickiness and enhancing usability.

[0055] R, as in equation 1 above 1 The hydrocarbon group in the name is not particularly limited, and examples include alkyl, cycloalkyl, alkenyl, alkynyl, cycloalkyl, haloalkyl, alkoxyalkyl, and alkoxycarbonylalkyl. From the viewpoint of improving undesirable properties such as stickiness, alkyl is a suitable hydrocarbon group.

[0056] In several embodiments, from the viewpoint of improving undesirable conditions such as stickiness, the R of the cyclic carboxamide derivative shown in Formula 1... 1 A hydroxyalkyl group having 1 to 3 carbon atoms, X being -CH2- or -NH-, and n being 1 is suitable. More specifically, cyclic carboxamide derivatives as shown below are more suitable, with 1-(2-hydroxyethyl)-2-imidazolidineone being particularly suitable.

[0057]

[0058] The cyclic carboxamide derivatives shown in Formula 1 above can be in the form of salts. There are no particular restrictions on the type of salt, as long as it is pharmacologically acceptable; it can be an inorganic or organic salt.

[0059] Examples of inorganic salts include, for example, hydrochlorides, sulfates, phosphates, hydrobromides, sodium salts, potassium salts, magnesium salts, calcium salts, magnesium salts, and ammonium salts.

[0060] Examples of organic salts include, for example, acetates, lactates, maleates, fumarates, tartrates, methanesulfonates, p-toluenesulfonates, triethanolamine salts, and amino acid salts.

[0061] These inorganic or organic salts can also be used for the aforementioned pyrrolidone carboxylates and lactates.

[0062] <(b) Polyglycerol fatty acid esters>

[0063] This disclosed oil-in-water emulsion cosmetic contains polyglycerol fatty acid esters. The polyglycerol fatty acid esters can be used directly as conventional surfactants, or, as described later in the method for manufacturing oil-in-water emulsion cosmetics, a substance obtained from a vesicle solution prepared using polyglycerol fatty acid esters can be used as a surfactant. The surfactant obtained from the vesicle solution prepared using polyglycerol fatty acid esters can form… Figure 1 The disclosed oil-in-water emulsion cosmetic can use a disc-shaped structure obtained by using polyglycerol fatty acid esters as a surfactant. From the viewpoint of improving the stickiness and other adverse effects associated with hygroscopic aqueous compounds and enhancing usability, it is preferable to use a substance obtained from a vesicle solution prepared using polyglycerol fatty acid esters, i.e., a disc-shaped structure, as a surfactant. Polyglycerol fatty acid esters can be used alone or in combination of two or more.

[0064] From the viewpoint of improving the stickiness and other adverse effects associated with hygroscopic aqueous compounds and enhancing usability, the amount of polyglycerol fatty acid ester mixed with the cosmetic is preferably 0.01% by mass or more or 0.05% by mass or more, more preferably 0.1% by mass or more, 0.3% by mass or more, or 0.5% by mass or more, and preferably 5.0% by mass or less, 3.0% by mass or less, 2.0% by mass or less, or 1.5% by mass or less, more preferably less than 1.5% by mass, 1.3% by mass or less, or 1.0% by mass or less. Hygroscopic aqueous compounds can be appropriately used within this range.

[0065] Polyglycerol fatty acid esters can be prepared by esterifying fatty acids with polyglycerol, as shown in the following reaction formula.

[0066] Here, in polyglycerol fatty acid esters, the portion derived from fatty acids can be called the fatty acid portion, and the portion derived from polyglycerol can be called the polyglycerol portion. The fatty acid portion is equivalent to the lipophilic portion, and the polyglycerol portion is equivalent to the hydrophilic portion.

[0067] From the viewpoint of improving the stickiness and other adverse conditions associated with hygroscopic aqueous compounds and improving usability, the number of carbon atoms in the fatty acid portion is preferably 12 or more, 13 or more, or 14 or more, and preferably 17 or less, 16 or less, 15 or less, or 14 or less.

[0068] The fatty acids that can be used in the preparation of polyglycerol fatty acid esters can be saturated or unsaturated fatty acids, and can be straight-chain or branched-chain fatty acids. Examples of such fatty acids include lauric acid, myristic acid, and palmitic acid. Among these, myristic acid and lauric acid are preferred.

[0069] From the viewpoint of improving the stickiness and other undesirable properties associated with hygroscopic aqueous compounds and enhancing usability, the polyglycerol portion of the polyglycerol fatty acid ester is preferably a trimer or a tetramer or a tetramer. Furthermore, it is more preferably a nine-mer or less, an eight-mer or less, a seven-mer or less, or a six-mer or less, and more preferably a tetramer or more and an eight-mer or less. Here, the value of n in the polyglycerol fatty acid ester in the above reaction formula is, for example, the same as the value 2 in the dimer.

[0070] Examples of polyglycerol fatty acid esters include, for instance, polyglycerol-6 myristate, polyglycerol-4 laurate, polyglycerol-5 laurate, polyglycerol-6 laurate, and polyglycerol-10 palmitate. Among these, polyglycerol-6 myristate and polyglycerol-6 laurate are preferred from the viewpoint of improving usability and reducing undesirable properties such as stickiness associated with hygroscopic aqueous compounds.

[0071] (Disc-shaped structure)

[0072] In several embodiments, the water-in-oil emulsion cosmetic of this disclosure comprises a disc-shaped structure containing a polyglycerol fatty acid ester as a surfactant. The polyglycerol fatty acid ester described above can also be used as the polyglycerol fatty acid ester constituting the disc-shaped structure.

[0073] The disc-shaped structure is formed by stacking monolayers with hydrophilic and oleophilic portions, and can be configured at the interface with the aqueous phase in an oil droplet.

[0074] From the perspective of surface activity (emulsification performance), the number of layers in a monolayer can be 3 or more, or 5 or more. There is no particular upper limit to the number of layers; for example, it can be 15 or less, 13 or less, 11 or less, 9 or less, or 7 or less.

[0075] The maximum length of one side of the cross-sectional shape of the disc-shaped structure, for example... Figure 1 The length in the width direction of the disk-shaped structure can be less than 500 nm, less than 400 nm, less than 300 nm, less than 200 nm, less than 100 nm, less than 90 nm, or less than 80 nm; alternatively, it can be more than 30 nm, more than 40 nm, or more than 50 nm. Here, when the cross-section of the disk-shaped structure is deformed in a manner that follows the curvature of the oil droplet shape, the maximum length is as follows... Figure 1 The figure shown refers to the length of the curved surface.

[0076] For example, the presence or absence of a disc-shaped structure and the maximum length of one side of the cross-sectional shape of the disc-shaped structure can be confirmed or determined using the cryo-replica method from photographs obtained by a cryo-replica transmission electron microscope (TEM, H-7650: manufactured by Hitachi, Ltd.). Furthermore, the maximum length of one side of the cross-sectional shape of the disc-shaped structure is the average of any three or more (e.g., ten) disc-shaped structures selected arbitrarily.

[0077] Consider disc-shaped structures such as Figure 1As shown, after the vesicles in the aqueous phase disintegrate and a portion of the monolayers constituting the vesicles are adsorbed onto the surface of the oil via the lipophilic (hydrophobic) portion, the bilayers constituting the vesicles are stacked on the hydrophilic portion of the monolayers, or the monolayers constituting the vesicle bilayers are stacked on each other via the hydrophilic portion or via the lipophilic portion, thereby forming a disc-shaped structure. That is, the monolayers of the disc-shaped structure are typically composed of at least one surfactant (e.g., polyglycerol fatty acid ester) capable of forming vesicles. In addition, the presence or absence of vesicles in cosmetics can be confirmed using, for example, the cryopreservation method using a cryopreservation transmission electron microscope (TEM, H-7650: manufactured by Hitachi, Ltd.), or a small-angle X-ray scattering apparatus (SAXSess, manufactured by Anton Paar) and Zetasizer Nano (manufactured by Malvern Panalytical).

[0078] In several embodiments, the disc-shaped structure is preferably formed from at least one polyglycerol fatty acid ester with an OH / C ratio of 0.30 to 0.80. This OH / C ratio is preferably 0.30 or higher, 0.35 or higher, 0.40 or higher, 0.45 or higher, or 0.50 or higher; more preferably, it is 0.80 or lower, 0.75 or lower, 0.70 or lower, 0.65 or lower, or 0.60 or lower. Polyglycerol fatty acid esters with such OH / C ratios readily form disc-shaped structures, which can further improve the emulsification stability of water-in-oil emulsion cosmetics and the improvement of undesirable conditions such as stickiness associated with hygroscopic aqueous compounds.

[0079] Here, the "OH / C ratio" as used in this disclosure refers to the ratio of the number of hydroxyl groups in the polyglycerol portion to the number of carbon atoms in the fatty acid portion, and is a parameter relating to the balance between hydrophilicity and lipophilicity. For example, in the case of polyglycerol-6-myristate, the number of carbon atoms in the fatty acid portion is 14, and the polyglycerol portion is a hexamer, in which case the number of hydroxyl groups is 7 (=6+1), so the OH / C ratio is 0.50 (=7 / 14).

[0080] Examples of polyglycerol fatty acid esters capable of forming disc-shaped structures include, for example, polyglycerol-6 myristate, polyglycerol-4 laurate, polyglycerol-5 laurate, polyglycerol-6 laurate, and polyglycerol-10 palmitate. Among these, polyglycerol-6 myristate and polyglycerol-6 laurate are preferred from the viewpoint of improving usability and reducing undesirable properties such as stickiness associated with hygroscopic aqueous compounds.

[0081] <(c) Oil content>

[0082] The water-in-oil emulsion cosmetic disclosed herein contains oil. Such oil can form oil droplets as an oil phase or dispersed phase together with the aforementioned polyglycerol fatty acid ester or a disc-shaped structure prepared using the polyglycerol fatty acid ester.

[0083] The disc-shaped structure can improve the emulsification stability of oil droplets in water-in-oil emulsion cosmetics. Therefore, in several embodiments, the average particle size of the oil droplets can be, for example, 10 μm or less, 7 μm or less, 5 μm or less, or 3 μm or less immediately after fabrication. The lower limit of the average particle size is not particularly limited; for example, it can be 500 nm or more, 700 nm or more, or 1 μm or more. Here, the average particle size of the oil droplets can be defined as the average diameter of the equivalent circle of the projected area of ​​10 or more, preferably 100 or more oil droplets observed under an optical microscope.

[0084] The oil content in the water-in-oil emulsion cosmetic disclosed herein, relative to the total amount of the cosmetic, can be 0.5% by mass or more, 1.0% by mass or more, 2.0% by mass or more, 3.0% by mass or more, 5.0% by mass or more, 7.0% by mass or more, 10% by mass or more, 15% by mass or more, 20% by mass or more, 25% by mass or more, or 30% by mass or more. Alternatively, it can be 50% by mass or less, 45% by mass or less, 40% by mass or less, 35% by mass or less, 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, 7.0% by mass or less, or 5.0% by mass or less. The oil content can be appropriately used within such ranges.

[0085] There are no particular restrictions on the type of oil; for example, volatile oils and non-volatile oils can be used. Oils can be used alone or in combination of two or more. Here, "volatility" refers to a volatile content exceeding 5% after being placed at atmospheric pressure and 105°C for 3 hours. The evaporation percentage, used as an indicator of volatility, can be 10% or more, 20% or more, 40% or more, 50% or more, 60% or more, 80% or more, or 100%. Alternatively, the boiling point at 1 atmosphere (101.325 kPa) can be used as an indicator of volatility. This boiling point can be below 250°C, below 240°C, or below 230°C; furthermore, it can be above 80°C, above 100°C, above 120°C, above 150°C, or above 160°C. Furthermore, in this disclosure, "non-volatile" refers to a volatile content of less than 5% after being placed at 105°C for 3 hours.

[0086] There are no particular limitations on volatile oils; examples include volatile silicone oils and volatile hydrocarbon oils. Volatile oils can be used alone or in combination of two or more.

[0087] Examples of volatile silicone oils include, for example, volatile acyclic silicone oils and volatile cyclic silicone oils.

[0088] As volatile acyclic silicone oils, for example, volatile linear silicone oils and volatile branched silicone oils can be used.

[0089] Examples of volatile linear silicone oils include, for instance, low molecular weight linear dimethyl polysiloxanes such as dimethyl polysiloxane with a viscosity of 0.65 cs (sometimes called "polydimethylsiloxane"), dimethyl polysiloxane with a viscosity of 1 cs, dimethyl polysiloxane with a viscosity of 1.5 cs, and dimethyl polysiloxane with a viscosity of 2 cs. Here, these viscosities refer to the kinematic viscosity at 25°C.

[0090] Examples of volatile branched silicone oils include, for example, low molecular weight branched siloxanes such as methyl polytrimethylsiloxane, tris(trimethylsilyl)methylsilane, and tetra(trimethylsilyl)silane.

[0091] Examples of volatile cyclic silicone oils include, for example, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecylcyclohexasiloxane.

[0092] Examples of volatile hydrocarbon oils include heptane, isododecane, isohexadecane, and isodecane.

[0093] Besides the volatile oils mentioned above, other oils commonly used in cosmetics include liquid oils, solid oils, waxes, hydrocarbon oils (other than those mentioned), silicone oils (other than those mentioned), and polar oils. In ultraviolet absorbers, there are also substances that function as oils, particularly polar oils. Such ultraviolet absorbers can also be considered as oils.

[0094] Examples of liquid oils include, for example, avocado oil, camellia oil, turtle oil, macadamia nut oil, corn oil, mink oil, olive oil, rapeseed oil, egg yolk oil, sesame oil, apricot kernel oil, wheat germ oil, camellia oil, castor oil, flaxseed oil, safflower oil, cottonseed oil, perilla oil, soybean oil, peanut oil, tea seed oil, torreya nut oil, rice bran oil, tung oil, Japanese tung oil, jojoba oil, wheat germ oil, and triglycerides.

[0095] Examples of solid fats include cocoa butter, coconut oil, horse fat, hardened coconut oil, palm oil, beef tallow, mutton tallow, hardened beef tallow, palm kernel oil, lard, beef bone fat, wood wax kernel oil, hardened oil, beef foot fat, wood wax, and hardened castor oil.

[0096] Examples of waxes include beeswax, candelilla wax, cotton wax, carnauba wax, bayberry wax, insect wax, whale wax, lignite wax, rice bran wax, lanolin, kapok wax, acetylated lanolin, liquid lanolin, sugarcane wax, lanolin fatty acid isopropyl ester, hexyl laurate, reduced lanolin, jojoba wax, hard lanolin, purpuric resin wax, POE lanolin alcohol ether, POE lanolin alcohol acetate, POE cholesterol ether, lanolin fatty acid polyethylene glycol, and POE hydrogenated lanolin alcohol ether.

[0097] Examples of hydrocarbon oils include, for example, liquid paraffin, ceresin, squalane, pterosin, paraffin, xylose, squalene, petrolatum, microcrystalline wax, and olefin oligomers.

[0098] Examples of silicone oils include chain-like organosilicones such as dimethylpolysiloxane (polydimethylsiloxane), methylphenylpolysiloxane (diphenylsiloxyphenylpolytrimethylsiloxane), and methylhydropolysiloxane with a viscosity of 6 cs or higher.

[0099] As a polar oil, for example, a polar oil with an IOB value of 0.10 or higher can be used. Examples of such polar oils include isopropyl myristate (IOB value = 0.18), octyl palmitate (IOB value = 0.13), isopropyl palmitate (IOB value = 0.16), butyl stearate (IOB value = 0.14), hexyl laurate (IOB value = 0.17), myristyl myristate (IOB value = 0.11), decyl oleate (IOB value = 0.11), isononyl isononanoate (IOB value = 0.20), and isotriadecyl isononanoate (IOB value = 0.20). IOB value = 0.15), Cetyl Ethylhexanoate (IOB value = 0.13), Pentaerythritol Tetraethylhexanoate (IOB value = 0.35), Diethylhexyl Succinate (IOB value = 0.32), Dioctyl Succinate (IOB value = 0.36), Glycol Distearate (IOB value = 0.16), Glyceryl Diisostearate (IOB value = 0.29), Neopentyl Didecanoate (IOB value = 0.25), Diisostearate Malate (IOB value = 0.15), Cetyl Ethyl Hexanoate (IOB value = 0.13), Pentaerythritol Tetraethyl Hexanoate (IOB value = 0.13), Diethylhexyl Succinate ... 0.28), Trimethylolpropane triisostearate (IOB value = 0.16), Tri-2-ethylhexanoate (glyceryl tri(ethylhexanoate) ester) (IOB value = 0.35), Trimethylolpropane trioctanoate (IOB value = 0.33), Trimethylolpropane triisostearate (IOB value = 0.16), Diisobutyl adipic acid (IOB value = 0.46), N-Lauroyl-L-glutamic acid-2-octyldodecyl ester (IOB value = 0.29), Adipic acid 2- Hexyldecyl ester (IOB value = 0.16), diisopropyl sebacate (IOB value = 0.40), ethylhexyl methoxycinnamate (IOB value = 0.28), 2-ethylhexyl palmitate (IOB value = 0.13), 2-ethylhexyl ethylhexanoate (IOB value = 0.2), triisostearate (IOB value = 0.16), dineovaleric acid PPG-3 (IOB value = 0.52), and tri(caprylic / capric)glyceride (IOB value = 0.33).

[0100] Examples of UV absorbers that can be considered as oil-based include those with an IOB of 0.10 or higher. Specifically, examples include organic UV absorbers such as ethylhexyl methoxycinnamate, octocrylene, polysiloxane-15, tert-butylmethoxydibenzoylmethane, ethylhexyl triazine, diethylhexyloxyphenol methoxyphenyl triazine, diethylaminohydroxybenzoyl benzoate, hydroxybenzophenone-3, methylenebisbenzotriazolyltetramethylbutylphenol, homosalate, and ethylhexyl salicylate. Two or more UV absorbers can be used alone or in combination.

[0101] The IOB values ​​of polar oils and UV absorbers can be, for example, 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, IOB value is short for Inorganic / Organic Balance, a value representing the ratio of inorganic to organic properties, and thus an indicator of the degree of polarity of an organic compound. Specifically, the IOB value is expressed as IOB value = inorganic value / organic value. Regarding the "inorganic value" and "organic value" respectively, for example, the "inorganic value" and "organic value" corresponding to various atoms or functional groups are set in such a way that the "organic value" for one carbon atom in the molecule is 20 and the "inorganic value" for one hydroxyl group is 100. The "inorganic value" and "organic value" of all atoms and functional groups in the organic compound are accumulated, thereby calculating the IOB value of the organic compound (see, for example, Yoshio Koda's book, "..."). (Organic Concept Map - Fundamentals and Applications -), pp. 11-17, Sankyo Publishing, 1984).

[0102] In several embodiments, from the viewpoint of improving the emulsification stability of oil-in-water emulsion cosmetics and the improvement of undesirable conditions such as stickiness associated with hygroscopic aqueous compounds, polar oils are preferred, and cetyl ethylhexanoate is more preferred.

[0103] <(d)water>

[0104] The water-in-oil emulsion cosmetic disclosed herein contains water as a dispersion medium (aqueous phase).

[0105] There are no particular restrictions on the amount of water used in the mixing process. For example, relative to the total amount of cosmetics, it can be 20% or more by mass, 30% or more by mass, 40% or more by mass, 50% or more by mass, 60% or more by mass, 70% or more by mass, 80% or more by mass, or 90% or more by mass. Alternatively, it can be 95% or less by mass, 90% or less by mass, 80% or less by mass, 70% or less by mass, 60% or less by mass, or 50% or less by mass. Water can be used appropriately within these ranges.

[0106] There are no particular limitations on the water that can be used in the water-in-oil emulsion cosmetics disclosed herein; for example, water used in cosmetics and quasi-drug products can be used. Examples of water that can be used include, for instance, ion-exchanged water, distilled water, ultrapure water, and tap water.

[0107] <Any component>

[0108] The water-in-oil emulsion cosmetic disclosed herein can be appropriately blended with various ingredients to a extent that does not adversely affect the effects of this disclosure. Examples of such ingredients include additives that are commonly blended into cosmetics, such as surfactants (other than the polyglycerol fatty acid esters mentioned above), moisturizers, thickeners, neutralizers, water-soluble polymers, oil-soluble polymers, film-forming agents, higher fatty acids, metal ion blocking agents, lower alcohols, higher alcohols, various extracts, sugars, amino acids, organic amines, polymeric emulsions, chelating agents, UV absorbers (other than the UV absorbers mentioned above), pH adjusters, skin nutrients, vitamins, water-soluble agents (other than the hygroscopic aqueous compounds mentioned above), oil-soluble agents, buffers, fading inhibitors, preservatives, dispersants, sprays, fillers, pigments, dyes, colorants, fragrances, etc. Any ingredient can be blended in the oil phase and / or the aqueous phase, and can be used alone or in combination of two or more.

[0109] The polyglycerol fatty acid esters or disc-shaped structures containing the polyglycerol fatty acid esters in the water-in-oil emulsion cosmetics disclosed herein function as surfactants. Therefore, although other surfactants besides these can be blended into the cosmetics, from the viewpoint of improving undesirable conditions such as stickiness associated with hygroscopic aqueous compounds and improving usability, the amount of these other surfactants blended relative to the total amount of the cosmetics is preferably 5.0% by mass or less, 3.0% by mass or less, 1.0% by mass or less, 0.5% by mass or less, 0.1% by mass or less, or 0.01% by mass or less. Furthermore, it is more preferable that these other surfactants are not blended.

[0110] Manufacturing Method of Water-in-Oil Emulsion Cosmetics

[0111] The water-in-oil emulsion cosmetic disclosed herein is not limited to the following methods, but can be manufactured as follows. The various materials described above can be used in the manufacture of the cosmetic.

[0112] A hygroscopic aqueous compound is mixed with water to prepare an aqueous phase fraction, and a polyglycerol fatty acid ester is mixed with oil to prepare an oil phase fraction. Then, by adding the oil phase fraction to the aqueous phase fraction and stirring and mixing, the oil-in-water emulsion cosmetic of this disclosure can be obtained.

[0113] Alternatively, an aqueous phase component comprising a hygroscopic aqueous compound, a polyglycerol fatty acid ester, and water is mixed to form a vesicle solution. Then, an oil phase component containing oil is added to this vesicle solution, and the mixture is stirred and mixed to obtain the oil-in-water emulsion cosmetic of this disclosure. According to this method, a disc-shaped structure containing a polyglycerol fatty acid ester that can function as a surfactant can be formed.

[0114] Formulations of Water-in-Oil Emulsion Cosmetics

[0115] There are no particular limitations on the dosage form of the water-in-oil emulsion cosmetic disclosed herein, and examples include liquid, emulsion, cream, gel, spray, and mousse. Here, the term "spray" in this disclosure may include mist spray, aerosol spray, etc.

[0116] Applications of water-in-oil emulsion cosmetics

[0117] The water-in-oil emulsion cosmetic disclosed herein can be used, for example, as a cosmetic that can be applied to the skin or hair.

[0118] The product form of the cosmetics disclosed herein is not particularly limited, and examples include, for instance, facial cosmetics such as toners, serums, lotions, and masks; color cosmetics such as foundations, lipsticks, and eyeshadows; sunscreen cosmetics (sunscreen agents); body cosmetics; hair cosmetics such as hair tonics, hair serums, conditioners, shampoos, hair dyes, and hair growth products; and ointments.

[0119] Example

[0120] The following examples illustrate the water-in-oil emulsion cosmetics of this disclosure in further detail, but the cosmetics of this disclosure are not limited to these examples. Furthermore, unless otherwise specified, the mixing amount will be expressed as a percentage by mass. In addition, the evaluation methods described in the examples are not limited to the cosmetics described in the examples, and can be applied similarly to cosmetics containing the above-described ingredients.

[0121] Examples 1-11 and Comparative Example 1

[0122] The water-in-oil emulsion cosmetics obtained by the formulation shown in Table 1 and the manufacturing method described below were evaluated as follows, and the results are shown in Table 1.

[0123] Evaluation Methods

[0124] (Usability Evaluation)

[0125] Ten professionals evaluated the usability of each cosmetic ingredient when applied to the skin using the following criteria. Since the speed of skin integration is also related to stickiness, cosmetic ingredients that integrate quickly into the skin can also be considered non-sticky and have excellent usability. A: 7-10 answers indicate faster integration with the skin.

[0126] B: 4-6 answers indicate faster skin integration.

[0127] C: 0-3 answers indicate faster skin integration.

[0128] <Methods for Manufacturing Cosmetics>

[0129] Using the formula shown in Table 1, an oil-in-water emulsion cosmetic was manufactured by the following method. Here, the numbers shown below correspond to the numbers on the left side of the ingredient names in the formula of Table 1.

[0130] (Example 1)

[0131] Materials No.1 to No.5 and No.9 were mixed evenly using a mixer to obtain an aqueous phase containing vesicles.

[0132] The oil from No. 8 was added to the obtained aqueous phase and mixed evenly with a mixer to obtain the oil-in-water emulsion cosmetic of Example 1. Furthermore, since the aqueous phase containing vesicles was used here, it is anticipated that the polyglycerol fatty acid esters would form a disc-shaped structure.

[0133] (Example 2)

[0134] Materials No.1 to No.4 and No.9 were uniformly mixed using a mixer to obtain the aqueous phase.

[0135] Materials No. 5 and No. 8 were added to the obtained aqueous phase and mixed evenly with a mixer to obtain the oil-in-water emulsion cosmetic of Example 2. Furthermore, since the aqueous phase containing vesicles was not used here, it was anticipated that the polyglycerol fatty acid esters would not form a disc-shaped structure.

[0136] (Examples 3-11)

[0137] The formulations were changed to those shown in Table 1, and the same procedures were followed as in Example 1 to obtain the oil-in-water emulsion cosmetics of Examples 3 to 11. Furthermore, since the aqueous phase containing vesicles was used in all cases, it was anticipated that the polyglycerol fatty acid esters would form a disc-shaped structure.

[0138] (Comparative Example 1)

[0139] Materials No.1 to No.4, No.7 and No.9 were uniformly mixed using a mixer to obtain the aqueous phase.

[0140] The oil from No. 8 was added to the obtained aqueous phase and mixed evenly with a mixer to obtain the water-in-oil emulsion cosmetic of Comparative Example 1.

[0141]

[0142] <result>

[0143] As described in Patent Documents 1 and 3, cosmetics containing hygroscopic aqueous compounds such as cyclic carboxamide derivatives are known to be prone to stickiness and other adverse conditions. However, as shown by the results in Table 1, it can be confirmed that the oil-in-water emulsion cosmetic prepared using polyglycerol fatty acid esters is a cosmetic with excellent usability that blends quickly into the skin and is not sticky, even when containing hygroscopic aqueous compounds.

[0144] The results from Examples 1 and 2 show that the cosmetic of Example 1, obtained using the aqueous phase containing vesicles, exhibits superior usability compared to the cosmetic of Example 2, obtained using the aqueous phase without vesicles. This difference is likely due to the formation of a disc-shaped structure containing polyglycerol fatty acid esters in Example 1.

[0145] As can be seen from the results of Examples 3 to 5, from the point of view of usability, the content of the hygroscopic aqueous compound is preferably 5.0% by mass or less, and more preferably less than 5.0% by mass.

[0146] The results of Examples 6 and 7 show that the content of thickener has little effect on usability.

[0147] As can be seen from the results of Examples 8 to 10, from the point of view of usability, the content of polyglycerol fatty acid ester is preferably 1.5% by mass or less, and more preferably less than 1.5% by mass.

[0148] As can be seen from the results of Example 11, even polyglycerol fatty acid esters other than polyglycerol-6 laurate can improve usability.

Claims

1. A water-in-oil emulsion cosmetic, comprising... (a) Hygroscopic aqueous compounds, (b) Polyglycerol fatty acid esters (c) Oil, and (d) Water.

2. The cosmetic according to claim 1, wherein (a) the hygroscopic aqueous compound is a cyclic carboxamide derivative or a salt thereof as shown in Formula 1. In Equation 1, R 1 It consists of a hydrocarbon group or hydrogen atom with 1 to 6 carbon atoms that can be replaced by a hydroxyl group. X is -CH2- or -N(R) 2 )-,in, R 2 It consists of a hydrocarbon group or hydrogen atom with 1 to 6 carbon atoms that can be replaced by a hydroxyl group, and n is an integer from 1 to 3.

3. The cosmetic according to claim 1 or 2, wherein the content of (a) the hygroscopic aqueous compound is less than 5.0% by mass.

4. The cosmetic according to claim 1 or 2, wherein the number of carbon atoms in the fatty acid portion of the (b) polyglycerol fatty acid ester is 12 or more and 14 or less.

5. The cosmetic according to claim 4, wherein the polyglycerol portion of the polyglycerol fatty acid ester (b) is formed of polyglycerol in the form of at least tetramers and at least eight-mers.

6. The cosmetic according to claim 1 or 2, wherein the content of (b) polyglycerol fatty acid ester is 0.01% by mass or more and 1.5% by mass or less.

7. A method for manufacturing the oil-in-water emulsion cosmetic as described in claim 1 or 2, the method comprising: An aqueous phase component comprising (a) the hygroscopic aqueous compound, (b) the polyglycerol fatty acid ester, and (d) water is mixed to form a vesicle solution; as well as An oil phase component containing the oil component (c) is added to the vesicle solution.

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