Oil-in-water emulsion cosmetic

Abstract

To provide an oil-in-water emulsion cosmetic with unconventional unique properties, exhibiting high penetration akin to that of a milky lotion, while delivering a cream-like rich texture during application to the skin, and also imparting a moist feel to the applied skin.SOLUTION: An oil-in-water emulsion cosmetic according to the present invention contains (A) a higher fatty acid, (B) a water-soluble polysaccharide with a molecular weight of 2,500,000 or more, (C) silica, and (D) a higher alcohol, where the content of (D) higher alcohol is below 0.95 mass% relative to the total amount of the oil-in-water emulsion cosmetic.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an oil-in-water emulsion cosmetic, more specifically, to an oil-in-water emulsion cosmetic that has a high penetration feel like a milky lotion, while having a rich feel like a cream (a rich feel or texture when used) when applied to the skin, and also imparts a moist feel to the skin after application. [Background technology]

[0002] The comfort of use is an important factor for skin care cosmetics. Emulsions in particular have the characteristics of being smooth and easy to spread on the skin when applied, having high penetration into the skin, and being non-sticky and light to the touch, while many consumers also expect them to have a rich feel or texture when used. In other words, there is a demand for oil-in-water emulsion cosmetics that maintain the light spreadability and excellent penetration of emulsions while also having the richness during application and moisturizing effect after application of creams.

[0003] Therefore, for example, it is conceivable to increase the viscosity of the emulsion by blending a certain amount or more of higher alcohol, thereby improving the richness and moisturizing effect. However, blending a large amount of higher alcohol tends to make the emulsion difficult to spread on the skin and impair the penetration power of the emulsion.

[0004] In addition, skin care cosmetics such as emulsions are often provided to consumers in containers such as stoppered bottles, dispensers, and pouches, and it is important to control the viscosity of the cosmetics to an appropriate level in order to ensure the way the cosmetics come out of the container and the stability of the formulation. However, cosmetics that have been blended with a certain amount of higher alcohol to increase their viscosity have good stability at high temperatures, but lose fluidity at low temperatures, making them difficult to remove from the container and difficult to handle.

[0005] Another attempt to impart a rich feel to oil-in-water emulsion cosmetics has been proposed, which involves the blending of a combination of two types of thickeners, an acrylamide thickener and hydroxypropyl methylcellulose (Patent Document 1). However, the improvement in the rich feel is still insufficient, and it has been confirmed that the feeling of penetration is impaired. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2019-89741 A DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0007] The present invention aims to provide an oil-in-water emulsion cosmetic having excellent properties unique to the present invention that have not been previously available, namely, a high penetration feeling like a milky lotion, a rich feeling like a cream when applied to the skin, and a moist feeling after application to the skin. [Means for solving the problem]

[0008] Means for Solving the Problems The present inventors have conducted extensive research to solve the above-mentioned problems and have discovered that by blending a higher fatty acid, a water-soluble polysaccharide having a specific molecular weight, silica, and a predetermined amount of a higher alcohol, it is possible to obtain an oil-in-water emulsion cosmetic that has the desired feeling of penetration, richness, and moistness, and further has excellent fluidity at low temperatures and stability at high temperatures, thereby completing the present invention.

[0009] That is, the present invention provides (A) Higher fatty acids, (B) a water-soluble polysaccharide having a molecular weight of 2.5 million or more; (C) silica, and (D) Higher alcohol Including, (D) the amount of higher alcohol is less than 0.95% by mass based on the total amount of the oil-in-water emulsion cosmetic; The present invention provides an oil-in-water emulsion cosmetic. Effect of the Invention

[0010] By having the above-mentioned composition, the oil-in-water emulsion cosmetic of the present invention can have a high penetration feeling like a milky lotion, a rich feeling like a cream when applied to the skin, and also impart a moist feeling to the skin after application. In addition, since it has excellent fluidity at low temperatures and stability at high temperatures, it also has the effect that the formulation stability during storage and the ease of removal from a container are less susceptible to the effects of temperature. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The oil-in-water emulsion cosmetic of the present invention is characterized in that it contains (A) a higher fatty acid, (B) a water-soluble polysaccharide having a molecular weight of 2.5 million or more, (C) silica, and (D) a higher alcohol, and contains the higher alcohol in a specific amount. The oil-in-water emulsion cosmetic of the present invention will be described in detail below.

[0012] <(A) Higher fatty acids> The (A) higher fatty acid is a higher fatty acid that is generally used in cosmetics and is represented by the general formula R1COOH, where R1 is preferably a linear or branched, saturated or unsaturated hydrocarbon group having 16 to 22 carbon atoms.

[0013] Specific examples of (A) higher fatty acids include palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, arachidonic acid, eicosapentaenoic acid, docosahexaenoic acid, behenic acid, elaidic acid, ricinoleic acid, isostearic acid, and the like.

[0014] The blending amount of the (A) higher fatty acid is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and is preferably 2.0% by mass or less, more preferably 1.5% by mass or less, based on the total amount of the oil-in-water emulsion cosmetic. Therefore, examples of the blending amount range include 0.1 to 2.0% by mass, 0.3 to 1.5% by mass, etc.

[0015] <(B) Water-soluble polysaccharide> The water-soluble polysaccharide (B) is a water-soluble polysaccharide having a polysaccharide or a derivative thereof as a basic skeleton and having a molecular weight of 2.5 million or more. Here, the molecular weight of the water-soluble polysaccharide (B) is a weight average molecular weight, and can be measured, for example, by the GPC method (gel permeation chromatography).

[0016] The molecular weight of the water-soluble polysaccharide (B) is 2.5 million or more, more preferably 5 million or more, and even more preferably 6 million or more. The upper limit of the molecular weight of the water-soluble polysaccharide (B) is not particularly limited, but is usually preferably 20 million or less, more preferably 10 million or less, and even more preferably 7.5 million or less.

[0017] (B) Examples of water-soluble polysaccharides include hyaluronic acid or its salts, acetylated hyaluronic acid or its salts, xanthan gum, succinoglycan, gellan gum, pectin, alginates, propylene glycol alginate, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose, etc. Among these, water-soluble polysaccharides derived from microorganisms such as xanthan gum, succinoglycan, and gellan gum are preferred, and it is preferable to include either one or both of xanthan gum and succinoglycan, since they are particularly salt-tolerant and unlikely to cause problems in stability, etc., even when used in combination with various drugs.

[0018] Preferred commercially available water-soluble polysaccharides (B) include, for example, LEOXAN (registered trademark) (succinoglucan; molecular weight 6 million, Solvay Nicca Co., Ltd.) and NOMCORT ZZ (xanthan gum; molecular weight 20 million, Nisshin Oillio Group, Ltd.).

[0019] The blending amount of the water-soluble polysaccharide (B) is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and preferably 0.50% by mass or less, more preferably 0.30% by mass or less, based on the total amount of the oil-in-water emulsion cosmetic. Therefore, examples of the blending amount range include 0.01 to 0.50% by mass, 0.05 to 0.30% by mass, etc.

[0020] <(C) Silica> As the (C) silica, silica that is usually blended in cosmetic materials can be used, and any of porous, non-porous, and hollow silica can be used.

[0021] Among these, (C) silica is preferably one having an oil absorption of 40 ml / 100 g or more, more preferably one having an oil absorption of 100 ml / 100 g or more. By blending silica having an oil absorption of 40 ml / 100 g or more, it is possible to further improve the richness, penetration, and moisturizing properties. In the present specification, the "oil absorption amount" is a value measured according to JIS K5101-13-2:2004 (boiled linseed oil method). Specifically, it can be determined by the following method. First, 1.5g of spherical anhydrous silicic acid sample is collected on a medicine wrapping paper and transferred to a glass measuring plate. Next, 4 or 5 drops of boiled linseed oil (specified in JIS K 5101) are dropped from a burette onto the sample at a time, and the whole is thoroughly kneaded with a palette knife each time. This dropping and kneading is repeated until the whole becomes a hard putty-like mass, and the last drop is kneaded into a spiral shape using a palette knife. The end point is when the last drop can be rolled into a spiral shape using a palette knife, and the oil absorption per 100g of sample is calculated using the following formula. Oil absorption amount (ml / 100g)=(A / W)×100 (A is the amount of boiled linseed oil dropped (mL), and W is the amount of sample taken (g).)

[0022] Preferred commercially available products of (C) silica include, for example, Sunsphere L-51 (oil absorption capacity 150 ml / 100 g, AGC Si-Tech Co., Ltd.), Sunsphere H-52 (oil absorption capacity 300 ml / 100 g, AGC Si-Tech Co., Ltd.), and BA4 (oil absorption capacity 40 mL / 100 g, JGC Catalysts and Chemicals Co., Ltd.).

[0023] The blending amount of (C) silica is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and preferably 3.0% by mass or less, more preferably 1.0% by mass or less, based on the total amount of the oil-in-water emulsion cosmetic. Therefore, the blending amount range may be 0.01 to 3.0% by mass, 0.05 to 1.0% by mass, etc.

[0024] <(D) Higher alcohol> The higher alcohol (D) is a higher alcohol commonly used in cosmetics, and is particularly preferably a higher alcohol having 16 to 22 carbon atoms. Preferred examples of the component (D) include cetyl alcohol, stearyl alcohol, oleyl alcohol, behenyl alcohol, etc. Among these, linear unbranched cetyl alcohol, stearyl alcohol, and behenyl alcohol are particularly preferred.

[0025] The blending amount of the (D) higher alcohol is less than 0.95% by mass, preferably 0.80% by mass or less, and more preferably 0.60% by mass or less, based on the total amount of the oil-in-water emulsion cosmetic. If the blending amount of the (D) higher alcohol is 0.95% by mass or more, the feeling of penetration may be poor. There is no particular lower limit to the blending amount of the (D) higher alcohol, but it is usually preferably 0.10% by mass or more, and more preferably 0.20% by mass or more.

[0026] <(D) / (A) weight ratio> In the oil-in-water emulsion cosmetic of the present invention, the weight ratio of the higher alcohol (D) to the higher fatty acid (A) ([(D) / (A) weight ratio]) is preferably 0.4 to 0.8, and more preferably 0.5 to 0.7. A (D) / (A) weight ratio within this range is preferable because it allows the formation of a gel that has a high penetration feel while also imparting sufficient viscosity and stability.

[0027] <Optional ingredients> The oil-in-water emulsion cosmetic of the present invention may contain, as necessary, appropriate components other than the above-mentioned (A) to (D), such as aqueous solvents, oils, moisturizing agents, drugs, as well as surfactants, chelating agents, preservatives, antioxidants, etc., within the scope that does not impair the effects of the present invention.

[0028] Examples of the aqueous solvent include water (purified water, ion-exchanged water, tap water, etc.), lower alcohols, and mixtures thereof.

[0029] The oil is not particularly limited, and various oils widely used in cosmetics can be blended. However, in the present invention, if the ratio of semi-solid / solid oil is too high, the viscosity of the cosmetic tends to increase, impairing the feeling of penetration and low-temperature fluidity, and if the ratio of liquid oil is too high, the viscosity of the cosmetic tends to decrease, resulting in insufficient richness, moistness, and high-temperature stability. Therefore, it is preferable to adjust the mass ratio of semi-solid / solid oil to liquid oil ([semi-solid / solid oil] / [liquid oil]) to be preferably in the range of 0.01 to 0.40, more preferably 0.05 to 0.30, and even more preferably 0.10 to 0.25. In the present invention, when calculating the mass ratio of the semi-solid / solid oil content to the liquid oil content ([semi-solid / solid oil content] / [liquid oil content]), the above (D) higher alcohol is included in the semi-solid / solid oil content. The total amount of oil is preferably 3% by mass or more, more preferably 5% by mass or more, and is preferably 25% by mass or less, more preferably 20% by mass or less, based on the total amount of the oil-in-water emulsion cosmetic. Thus, examples of the range of the total amount of oil include 3 to 25% by mass, 5 to 20% by mass, etc.

[0030] Semi-solid or solid oils are oils that are semi-solid or solid at room temperature (25°C). Examples of such oils include solid oils and fats such as cacao butter, coconut oil, horse oil, hardened coconut oil, palm oil, beef tallow, mutton tallow, hardened beef tallow, palm kernel oil, lard, beef bone oil, Japan wax kernel oil, hardened oil, cow foot fat, Japan wax, and hardened castor oil; beeswax, candelilla wax, cotton wax, carnauba wax, bayberry wax, Japanese laurel wax, whale wax, montan wax, rice bran wax, lanolin, kapok wax, lanolin acetate, sugarcane wax, lanolin fatty acid isopropyl, reduced lanolin, jojoba wax, hard lanolin, shellac wax, and the like. Examples of waxes include POE lanolin alcohol ether, POE lanolin alcohol acetate, POE cholesterol ether, and POE hydrogenated lanolin alcohol ether; hydrocarbon waxes such as polyethylene wax, paraffin wax, ceresin, petrolatum, microcrystalline wax, and Lunacera; and fatty acid glyceryl ethers such as monostearyl glycerin ether (batyl alcohol). These can be used alone or in combination of two or more.

[0031] Liquid oils are oils that are liquid at room temperature (25° C.). Examples of such oils include liquid fats and oils such as avocado oil, evening primrose oil, camellia oil, turtle oil, macadamia nut oil, sunflower oil, almond oil, corn oil, mink oil, olive oil, rapeseed oil, egg yolk oil, sesame oil, persic oil, wheat germ oil, sasanqua oil, castor oil, linseed oil, safflower oil, cottonseed oil, perilla oil, soybean oil, peanut oil, tea seed oil, kaya oil, rice bran oil, Chinese tung oil, Japanese tung oil, jojoba oil, and germ oil; cetyl octanoate, cetyl 2-ethylhexanoate, dimethyl octane, and the like. Hexyldecyl myristate, ethyl laurate, isopropyl myristate, 2-hexyldecyl myristate, myristyl myristate, octyldodecyl myristate, isopropyl palmitate, 2-ethylhexyl palmitate, 2-hexyldecyl palmitate, 2-heptylundecyl palmitate, butyl stearate, isocetyl stearate, isocetyl isostearate, decyl oleate, dodecyl oleate, oleyl oleate, myristyl lactate, cetyl lactate, apple Diisostearyl acid, cholesteryl 12-hydroxystearyl acid, castor oil fatty acid methyl ester, 2-ethylhexyl succinate, diisobutyl adipate, 2-hexyldecyl adipate, di-2-heptylundecyl adipate, diisopropyl sebacate, di-2-ethylhexyl sebacate, ethylene glycol di-2-ethylhexanoate, neopentyl glycol dicaprate, neopentyl glycol dioctanoate, di-2-heptylundecanoate, glycerin, trioctyl ester oils such as glycerin phosphate, glycerin tri-2-ethylhexanoate, glycerin trimyristate, glycerin triisopalmitate, trimethylolpropane tri-2-ethylhexanoate, trimethylolpropane triisostearate, pentaerythritol tetraoctanoate, pentaerythritol tetra-2-ethylhexanoate, triethylhexanoin, and cetyl ethylhexanoate; hydrocarbon oils such as liquid paraffin, squalene, pristane, polybutene, and hydrogenated polydecene;Examples of silicone oils include chain polysiloxanes such as dimethylpolysiloxane, methylphenylpolysiloxane, and diphenylpolysiloxane, cyclic polysiloxanes such as octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecamethylcyclohexanesiloxane, and various modified polysiloxanes such as amino-modified polysiloxanes, polyether-modified polysiloxanes, alkyl-modified polysiloxanes, and fluorine-modified polysiloxanes, and these can be used alone or in combination of two or more kinds.

[0032] Moisturizing agents include polyoxyalkylene-polyoxyethylene copolymer dialkyl ether, 1,3-butylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, hexylene glycol, glycerin, diglycerin, xylitol, maltitol, maltose, D-mannitol, etc.

[0033] As the drug, a wide variety of drugs that are commonly used in cosmetics and have whitening effects, skin roughness improving effects, anti-acne effects, etc. can be blended. Among them, it is preferable to blend (E) a water-soluble component having at least one carboxyl group or a salt thereof. Examples of (E) water-soluble components include ascorbic acid, salicylic acid, tranexamic acid, kojic acid, ellagic acid, alkoxysalicylic acid, nicotinamide, and glycyrrhizinic acid, as well as salts or derivatives thereof (e.g., sodium L-ascorbate, magnesium L-ascorbate, L-ascorbyl glucoside, 2-O-ethyl-L-ascorbic acid, 3-O-ethyl-L-ascorbic acid, sodium 4-methoxysalicylate, potassium 4-methoxysalicylate, dipotassium glycyrrhizinate, and stearyl glycyrrhizinate). The oil-in-water emulsion cosmetic of the present invention is thickened by the water-soluble polysaccharide (B), which has high salt tolerance among water-soluble thickeners, and therefore usability and stability are unlikely to be impaired even if the above-mentioned drugs are blended in large amounts. For example, the blending amount of the water-soluble component (E) can be 0.01 to 5.00 mass%, further 0.05 to 3.00 mass%, or even 0.4 to 1.2 mass%, etc., based on the total amount of the oil-in-water emulsion cosmetic.

[0034] <Viscosity> The oil-in-water emulsion cosmetic of the present invention preferably has a viscosity of 15,000 mPa s or less, and more preferably 10,000 mPa s or less, as measured with a Brookfield viscometer at 0° C. If the viscosity at 0° C. is 15,000 mPa s or less, excellent fluidity can be maintained even at low temperatures. Furthermore, the oil-in-water emulsion cosmetic of the present invention preferably has a viscosity of 500 mPa s or more, and more preferably 1500 mPa s or more, measured with a B-type viscometer at 50° C. If the viscosity at 50° C. is 500 mPa s or more, excellent stability can be maintained even at high temperatures.

[0035] <Production method> The oil-in-water emulsion cosmetic of the present invention is not particularly limited, but can be produced, for example, by adding an oil part containing component (A), component (D) and other oily components, and component (C) to an aqueous phase part containing component (B) and other aqueous components, and emulsifying the mixture by a conventional method.

[0036] The oil-in-water emulsion cosmetic of the present invention can be provided as a skin care cosmetic such as a milky lotion, and is particularly suitable for provision in a bottle container or a pouch container. EXAMPLES

[0037] The present invention will be described in more detail below with reference to specific examples, but the present invention is not limited to the following examples. In addition, the blending amounts in the following examples are expressed as mass% relative to the total amount of the cosmetic unless otherwise specified. Before describing each example in detail, the evaluation methods used will be described.

[0038] (1) Fluidity at low temperatures The viscosity of each cosmetic material (sample) stored at 0° C. was measured using a B-type viscometer (rotor No. 3). The fluidity at low temperatures was evaluated from the obtained viscosity according to the following evaluation criteria.

[0039] <Evaluation criteria> A: Viscosity is 10,000 mPa s or less B: Viscosity is greater than 10,000 mPa·s and less than 15,000 mPa·s C: Viscosity higher than 15000mPa·s

[0040] (2) Stability at high temperatures The viscosity of each cosmetic material (sample) stored at 50° C. was measured using a B-type viscometer (rotor No. 3). From the obtained viscosity, the stability at high temperatures was evaluated according to the following evaluation criteria.

[0041] <Evaluation criteria> A: Viscosity is 1500mPa·s or more B: Viscosity is 500 mPa s or more and less than 1500 mPa s C: Viscosity less than 500 mPa·s

[0042] (3) Richness Each cosmetic (sample) was used by a specialist panel, and the richness felt during application was evaluated according to the following criteria. <Evaluation criteria> A: It feels very rich when applied. B: Feels rich during application C: Not much richness during application D: No richness during application

[0043] (4) Penetration feeling Each cosmetic product (sample) was used by a specialist panel, and the feeling of penetration into the skin during application was evaluated according to the following criteria. <Evaluation criteria> A: It feels very penetrating during application. B: Feels like it is being absorbed during application C: There is little feeling of penetration during application D: No feeling of penetration during application

[0044] (5) Moisture Each cosmetic sample was used by a panel of experts, who evaluated the moisturizing effect after application according to the following criteria. <Evaluation criteria> A: Very moisturizing during application B: Moist during application C: Not very moist during application D: Not moisturized during application

[0045] [Examples 1 to 12 and Comparative Examples 1 to 5] The oil-in-water emulsion cosmetics shown in Table 1 below were prepared and evaluated for the above items (1) to (5).

[0046] [Table 1A]

[0047] [Table 1B]

[0048] As shown in Table 1, the oil-in-water emulsion cosmetic containing (A) a higher fatty acid, (B) a water-soluble polysaccharide having a molecular weight of 2.5 million or more, (C) silica, and (D) a higher alcohol, in which the blending amount of (D) the higher alcohol is less than 0.95 mass% based on the total amount of the oil-in-water emulsion cosmetic, showed sufficient results in all evaluation items (Examples 1 to 12). On the other hand, when neither (A) the higher fatty acid nor (D) the higher alcohol was contained, the richness, penetration feeling and moisturizing effect were significantly inferior (Comparative Example 1). In addition, when (B) the water-soluble polysaccharide having a molecular weight of 2.5 million or more was not blended, and instead a compound selected from xanthan gum (molecular weight 1.2 million), carbomer, and (sodium acrylate / sodium acryloyldimethyltaurate) copolymer was blended, one of the evaluation items was significantly inferior (Comparative Examples 2 and 3). (C) When barium sulfate was used as a powder to replace silica, a sufficient richness and penetration were not obtained (Comparative Example 4). Furthermore, when the (D) higher alcohol was blended in an amount exceeding 0.95 mass %, the penetration feeling and fluidity at low temperatures were impaired (Comparative Example 5).

Claims

1. (A) higher fatty acid, (B) a water-soluble polysaccharide having a molecular weight of 2.5 million or more; (C) silica, and (D) Higher alcohol Including, (D) the blending amount of the higher alcohol is less than 0.95% by mass based on the total amount of the oil-in-water emulsion cosmetic; Oil-in-water emulsion cosmetic.

2. 2. The oil-in-water emulsion cosmetic according to claim 1, wherein the higher fatty acid (A) is a higher fatty acid having 16 to 22 carbon atoms.

3. The oil-in-water emulsion cosmetic according to claim 1, wherein the higher alcohol (D) is a higher alcohol having 16 to 22 carbon atoms.

4. 2. The oil-in-water emulsion cosmetic according to claim 1, wherein the water-soluble polysaccharide (B) is either one or both of succinoglycan and xanthan gum.

5. 2. The oil-in-water emulsion cosmetic according to claim 1, wherein the silica (C) has an oil absorption of 40 mL / 100 g or more.

6. The oil-in-water emulsion cosmetic according to claim 1, further comprising (E) a water-soluble component having at least one carboxyl group or a salt thereof.

7. The oil-in-water emulsion cosmetic according to claim 1 , which is provided in a bottle container or a pouch container.

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