Water-based oil-based acidic emulsified cosmetics

Abstract

There was a need for an oil-in-water emulsion cosmetic that offered excellent storage stability, spread smoothly and refreshingly upon application, and provided a firm, non-sticky feeling after application. [Solution] We have found that an oil-in-water acidic emulsion cosmetic containing components (A) to (D) and having a pH in the range of 4.5 to 5.5 exhibits excellent storage stability, spreads smoothly and refreshingly upon application, and provides a firm, non-sticky feeling of tightness after application. Ingredient (A): S-lactoyl glutathione Ingredient (B): Acrylic acid-based thickener Ingredients (C): Aqueous emulsion of acrylic polymer Component (D): Acidic substance

Description

Technical Field

[0001] The present invention relates to an oil-in-water type acidic emulsified cosmetic that has excellent storage stability, stretches smoothly during application, and provides a firm and non-sticky feeling after application.

Background Art

[0002] Cosmetics that stretch smoothly and do not stick after application tend to be favored by consumers due to their pleasant tactile properties. Conventionally, an oil-in-water emulsification technique has been used to obtain such tactile properties.

[0003] In oil-in-water emulsified cosmetics, acrylic acid-based water-soluble polymer thickeners such as carbomer are widely used for the purpose of improving storage stability. The acrylic acid-based water-soluble polymer thickener is generally used after being neutralized with a basic substance (see, for example, Patent Document 1).

[0004] In addition to the above tactile properties, cosmetics that provide a firm feeling after application can give a high sense of effectiveness due to the feeling of the skin being tightened. For the purpose of imparting firmness to the skin, emulsified cosmetics containing a solid higher alcohol, a liquid higher alcohol, and phospholipid at room temperature have been proposed (see Patent Document 2). However, in the invention described in Patent Document 2, it is necessary to blend a relatively large amount of solid oil components, and the stretch during application tends to become heavy. Also, when the ratio of liquid oil components is increased to improve stretch, not only is the firm feeling insufficient, but there is also a problem of feeling sticky.

[0005] On the other hand, S-lactyl glutathione is a thiol ester of lactic acid and glutathione, and technologies such as anti-inflammatory agents (Patent Document 3), whitening agents (Patent Document 4), and antithrombotic drugs (Patent Document 5) have been disclosed.

[0006] Although S-lactoyl glutathione possesses excellent physiological activity, it is particularly prone to decomposition in basic aqueous solutions, and tends to emit an unpleasant odor derived from its decomposition products, posing a challenge to its storage stability.

[0007] Against this backdrop, there is a need for an oil-in-water emulsion cosmetic that contains S-lactoyl glutathione, yet possesses excellent storage stability, spreads smoothly and refreshingly upon application, and provides a firm, non-sticky feeling after application. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 59-39814 [Patent Document 2] Japanese Patent Publication No. 2005-53879 [Patent Document 3] Japanese Patent Publication No. 63-267727 [Patent Document 4] Japanese Patent Application Publication No. 3-133913 [Patent Document 5] Japanese Patent Publication No. 2011-74049 [Overview of the project] [Problems that the invention aims to solve]

[0009] The present invention has been made in view of the above circumstances, and aims to provide an oil-in-water emulsion cosmetic that has excellent storage stability, spreads smoothly and refreshingly when applied, and provides a firm, non-sticky feeling of elasticity after application. [Means for solving the problem]

[0010] Under these circumstances, the inventors of the present invention have diligently conducted research to solve the above problems and have found that an oil-in-water acidic emulsion cosmetic containing the following components (A) to (D) and having a pH in the range of 4.5 to 5.5 exhibits excellent storage stability, spreads smoothly and refreshingly upon application, and provides a firm, non-sticky feeling of elasticity after application, thus completing the present invention. Ingredient (A): S-lactoyl glutathione Ingredient (B): Acrylic acid-based thickener Ingredients (C): Aqueous emulsion of acrylic polymer Component (D): Acidic substance [Effects of the Invention]

[0011] The present invention provides an oil-in-water emulsion cosmetic composition characterized by containing a polymeric thickener such as S-lactoyl glutathione and carbomer, an aqueous emulsion of an acrylic acid polymer, and an acidic substance as essential components.

[0012] According to the present invention, it is possible to provide an oil-in-water emulsion cosmetic that has excellent storage stability, spreads smoothly and refreshingly when applied, and provides a firm, non-sticky feeling of elasticity after application. [Modes for carrying out the invention]

[0013] The oil-in-water type acidic emulsion cosmetic of the present invention, which has excellent storage stability, spreads smoothly and refreshingly when applied, and provides a firm, non-sticky feeling after application, will be described below based on a preferred embodiment thereof.

[0014] The content of component (A) in the oil-in-water acidic emulsion cosmetic of the present invention is not particularly limited, but is 0.005 to 0.05% by weight. If it is 0.005% by weight or more, the physiological activity effects such as anti-inflammatory effects described above can be sufficiently exhibited, but if it is more than 0.05% by weight, the storage stability may not be sufficient.

[0015] The component (B) contained in the oil-in-water acidic emulsion cosmetic of the present invention is not particularly limited as long as it is an acrylic acid-based thickener commonly used in cosmetics. Examples include, but are not limited to, carbomer, polyacrylamide, acrylic acid / alkyl methacrylate copolymer, (sodium acrylate / sodium acryloyldimethyl taurate) copolymer, polyacrylate-13, etc. Furthermore, these acrylic acid-based thickeners may be used individually or in combination of two or more.

[0016] The content of component (B) in the oil-in-water acidic emulsion cosmetic of the present invention is not particularly limited, but is 0.001 to 1% by weight. Preferably, it is 0.01 to 0.5% by weight. If it is less than 0.001% by weight, the storage stability may not be sufficient, and if it is more than 1% by weight, it may affect the feel of the product.

[0017] Component (C) contained in the oil-in-water acidic emulsion cosmetic of the present invention is not particularly limited as long as it is an aqueous emulsion of an acrylic acid polymer commonly used in cosmetics. Examples include, but are not limited to, alkyl acrylate copolymer emulsions. Examples of commercially available products include Yodozol GH800F (solids content concentration 45% by weight, manufactured by Nurion Japan Co., Ltd.) and Yodozol GH810F (solids content concentration 46% by weight, manufactured by Nurion Japan Co., Ltd.). Furthermore, these aqueous emulsions of acrylic acid polymers may be used individually or in combination of two or more types.

[0018] The content of component (C) in the oil-in-water acidic emulsion cosmetic of the present invention is not particularly limited, but is 0.01 to 2% by weight as solid content. Preferably, it is 0.1 to 1% by weight. If it is less than 0.01% by weight, sufficient firmness may not be obtained, and if it is more than 2% by weight, a fresh feeling when applied may not be obtained.

[0019] Component (D) contained in the oil-in-water type acidic emulsified cosmetic of the present invention is not particularly limited as long as it is an acidic substance usually used in cosmetics. For example, citric acid, lactic acid, succinic acid, malic acid, tartaric acid, etc. can be mentioned, but it is not necessarily limited to these. Also, these acidic substances may be used alone or in combination of two or more kinds.

[0020] Component (E) contained in the oil-in-water type acidic emulsified cosmetic of the present invention is not particularly limited as long as it is a polyhydric alcohol usually used in cosmetics. For example, BG, DPG, glycerin, polyglycerin, ethylene glycol, polyethylene glycol, polypropylene glycol, etc. can be mentioned, but it is not necessarily limited to these. Also, these polyhydric alcohols may be used alone or in combination of two or more kinds.

[0021] In the oil-in-water type acidic emulsified cosmetic of the present invention, "acidic" means that the pH value of the oil-in-water type emulsified cosmetic of the present invention at 25°C is less than 7, preferably 5.5 or less, and the lower limit is not particularly limited, but it is preferably 4.5 or more. When the oil-in-water type emulsified cosmetic of the present invention is not acidic, that is, when the pH value is 7 or more, it may affect the feeling of use. On the other hand, when the pH value is lower than 4.5, the storage stability may not be sufficient. The pH value of the oil-in-water type acidic emulsified cosmetic of the present invention is the value measured at 25°C for the stock solution of the emulsified cosmetic in accordance with JIS Z8802:2011.

[0022] In the oil-in-water type acidic emulsified cosmetic of the present invention, "firmness" means a feeling that a thin film is formed on the surface of the skin after applying the emulsified cosmetic, and further, when touching the skin, it is smooth and has a slippery feeling.

[0023] Furthermore, in addition to the above-mentioned components contained in the oil-in-water acidic emulsion cosmetic of the present invention, powders commonly used in cosmetics may also be included. Examples include inorganic powders such as talc, sericite, mica, synthetic mica, silica, barium sulfate, alumina, boron nitride, titanium dioxide, iron oxide, and zinc oxide, and organic powders such as silk powder and crystalline cellulose powder. One or more of these may be used.

[0024] Furthermore, in addition to the above-mentioned components contained in the oil-in-water acidic emulsion cosmetic of the present invention, other components commonly used in cosmetics may be included, depending on the intended use, as long as they do not impair the effects of the invention. Examples include water-retaining agents, oily components, anionic surfactants, cationic surfactants, nonionic surfactants, fragrances, medicinal components, cooling agents, UV absorbers, stabilizers, antioxidants, preservatives, viscosity modifiers other than component (B) of the present invention, pH adjusters other than component (D) of the present invention, and cosmetic components.

[0025] Oily components include, for example, oils and fats such as olive oil, camellia oil, macadamia nut oil, and avocado oil; waxes such as carnauba wax, candelilla wax, jojoba oil, beeswax, and lanolin; hydrocarbons such as liquid paraffin, paraffin, petrolatum, ceresin, microcrystalline wax, squalene, and squalane; silicones such as methylpolysiloxane, methylphenylpolysiloxane, methylcyclopolysiloxane, octamethylcyclotetrasiloxane, octamethylcyclopentasiloxane, decamethylcyclopentasiloxane, and methylhydrogenpolysiloxane; isopropyl myristate, 2-octyldodecyl myristate, cetyl 2-ethylhexanoate, and 2-ethylhexyl palmitate. Examples include fatty acid esters such as di-2-ethylhexanoate neopentyl glycol, tri-2-ethylhexanoate glycerol, 2-octyldodecyl oleate, glycerol triisostearate, tri-2-ethylhexanoate glycerol, 2-octyldodecyl oleate, diisostearyl malate, glycerol triisostearate, and diglyceride 2-ethylhexanoate; higher alcohols such as cetyl alcohol, stearyl alcohol, isostearyl alcohol, 2-octyldodecanol, and oleyl alcohol; and higher fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, and oleic acid. One or more of these can be used.

[0026] Examples of surfactants include nonionic surfactants such as sorbitan fatty acid esters, glycerin fatty acid esters, castor oil, hydrogenated castor oil, and their alkylene oxide adducts, polyglycerin fatty acid esters, polyoxyalkylene alkyl ethers, polyoxyalkylene fatty acid esters, polyoxyalkylene alkylphenols, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene alkylphenyl formaldehyde condensates, polyoxyethylene sterols and their derivatives, polyoxyethylene lanolin and its derivatives, polyoxyethylene beeswax derivatives, sugar esters, higher fatty acid soaps, alkyl sulfate salts, alkyl phosphates, polyoxyethylene alkyl ether sulfates, polyoxyethylene alkylphenyl ether sulfates, alkyl ether phosphates, alkyl ether carboxylates, acylmethyl taurate salts, N-acyl-N-methyl-β-alanine salts, N-acylglycine salts, N-acyl glutamate salts, polyoxyethylene alkyl carboxylates, alkylphenyl ether sulfonates, Examples of amphoteric surfactants include anionic surfactants such as N-acyl sarcosine and its salts, polyoxyethylene coconut oil fatty acid monoethanolamide sulfate, amine salts such as alkylamine salts, fatty acid amideamine salts, and ester-containing tertiary amine salts, alkyl quaternary ammonium salts such as monoalkyl type quaternary ammonium salts, dialkyl type quaternary ammonium salts, trialkyl type quaternary ammonium salts, and benzalkonium type quaternary ammonium salts, cyclic quaternary ammonium salts such as alkylpyridinium salts, cationic surfactants such as benzethonium chloride, glycine type amphoteric surfactants such as alkylglycine salts, carboxymethylglycine salts, and N-acylaminoethyl-N-2-hydroxyethylglycine salt, aminopropionic acid type amphoteric surfactants such as alkylaminopropionate salts and alkyliminodipropionate salts, aminoacetic acid betaine type amphoteric surfactants such as alkyldimethylaminoacetic acid betaine and fatty acid amidopropyldimethylaminoacetic acid betaine, and sulfobetaine type amphoteric surfactants such as alkylhydroxysulfobetaine. One or more of these can be used.

[0027] The oil-in-water acidic emulsion cosmetic of the present invention is prepared by stirring and mixing the constituent components using a conventional cosmetic manufacturing apparatus. Specifically, each component belonging to the aqueous phase is mixed, and it is confirmed that the solid components have completely dissolved to form a uniformly dissolved and dispersed aqueous phase mixture. Similarly, each component belonging to the oil phase is mixed while being heated, and it is confirmed that the solid components have completely melted to form a uniformly dissolved and dispersed oil phase mixture. The heated aqueous phase mixture is added to the obtained oil phase mixture, and homogenization is performed using a stirring paddle while maintaining the temperature. By homogenizing at a constant rotation speed and cooling to room temperature, the oil-in-water acidic emulsion cosmetic of the present invention is prepared. [Examples]

[0028] The oil-in-water acidic emulsion cosmetic composition of the present invention will be described in more detail below with reference to examples, but the technical scope of the present invention is not limited to these examples. The values ​​in the table represent the content (weight %).

[0029] (Examples 1-15 and Comparative Examples 1-5) Oil-in-water emulsion cosmetics were prepared using the formulations shown in Tables 1 and 2 below and the preparation method described below. For each sample obtained, the storage stability (emulsification state over time, presence or absence of off-odor) and the feel (freshness, non-stickiness, and firmness) were evaluated using the evaluation method described below, and these results are also listed in Tables 1 and 2.

[0030] (Preparation method) The oil phases shown in Tables 1 and 2 were mixed and uniformly dissolved while being heated to 80-85°C. Next, the aqueous phase 1 was uniformly dissolved and dispersed at room temperature using a homomixer. The aqueous phase 1, heated to 85-90°C, was gradually added to the oil phase, and homogenization was carried out using a stirring paddle while maintaining the temperature at 80-85°C. After cooling to room temperature, the uniformly dissolved aqueous phase 2 was added. The mixture was then uniformly mixed again using a stirring paddle to prepare an emulsion.

[0031] (Storage stability evaluation method: Evaluation 1) The oil-in-water emulsion cosmetic compositions (lotions) of the following examples and comparative examples were left to stand for 6 months in a constant temperature bath maintained at 40°C, and then evaluated for their "emulsification state (evaluation 1)" according to the following criteria. <Judgment criteria> [Appearance and emulsified particles] [Judgment] No aggregation or coalescence was observed, and no separation or precipitation was seen in appearance: ◎ Slight aggregation is observed, but no visible separation or precipitation is seen: ○ Aggregation and coalescence are observed, but no visible separation or precipitation is seen: △ Aggregation and coalescence are observed, and separation and precipitation are also visible in appearance: ×

[0032] (Storage stability evaluation method: Evaluation 2) The oil-in-water emulsion cosmetics (lotions) of the following examples and comparative examples were left to stand for one month in a constant temperature bath maintained at 40°C. Afterward, five trained professional panelists in their 20s to 40s evaluated the "absence of off-odors (evaluation 2)." Each panelist assigned a score according to the following evaluation criteria, and the average score was calculated for each oil-in-water emulsion cosmetic. The evaluation was then determined according to the following criteria. <Evaluation Criteria> [Degree of odor] [Rating] I don't feel anything at all: 5 I barely feel it: 4 I can faintly feel it: 3 Slightly strong feeling: 2 I feel it strongly: 1 <Judgment criteria> [Average score] [Judgment] 4.5 or higher ◎ 3.5 or higher, less than 4.5 ○ 2 or more and less than 3.5 △ Less than 2 ×

[0033] (Evaluation method for user experience: rating 3-5) A panel of 10 cosmetics experts aged 20-40 evaluated the feel of the oil-in-water emulsion cosmetics (lotions) described in the following examples and comparative examples when applied directly to the back of the hand or cheek. They assessed the following aspects: "freshness upon application (rating 3)", "non-stickiness after application (rating 4)", and "firmness after application (rating 5)". Each participant assigned a score according to the following evaluation criteria, and the average score for each lotion was calculated and judged according to the following criteria. <Evaluation Criteria> [User experience] [Rating] Excellent: 5 Good :4 Normal: 3 Slightly poor: 2 Bad :1 <Judgment criteria> [Average score] [Judgment] 4.5 or higher ◎ 3.5 or higher, less than 4.5 ○ 2 or more and less than 3.5 △ Less than 2 ×

[0034] [Table 1] *1: NIKKOL HCO-5 (manufactured by Nikko Chemicals Co., Ltd.) *2: NIKKOL HCO-20 (manufactured by Nikko Chemicals Co., Ltd.) *3: NIKKOL HCO-40 (manufactured by Nikko Chemicals Co., Ltd.) *4:NTC-CARBOMER 381 (manufactured by Guangzhou Tinci Materials Technology) *5: Yodzol GH800F (Solid content concentration 45% by weight, manufactured by Nurion Japan Co., Ltd.)

[0035] [Table 2]

[0036] From the results in Tables 1 and 2, oil-in-water acidic emulsion cosmetics with excellent storage stability and usability were obtained in Examples 1 to 15. Furthermore, the oil-in-water acidic emulsion cosmetics of Examples 1, 4, 5, 7, 8, 11, 12, 14, and 15, which had a pH within the range of 4.5 to 5.5 and within the preferred content range of components (B) and (C), showed particularly excellent storage stability and usability. On the other hand, Comparative Example 1, which did not contain component (B), did not have sufficient storage stability (emulsification state). Also, Comparative Example 2, which did not contain component (C), had an unsatisfactory usability, and a satisfactory feeling of "firmness" was not obtained. Furthermore, in Comparative Examples 3 to 5, which had a pH outside the range of 4.5 to 5.5, storage stability (absence of off-odor) or storage stability (emulsification state) was insufficient, and the usability tended to worsen, especially when the pH was greater than 5.5. Furthermore, in Examples 2 (total polyhydric alcohol content 0% by weight) and 3 (total polyhydric alcohol content 11% by weight), which did not contain component (E) or contained less than 20% by weight, the user experience was slightly inferior compared to Example 1 (total polyhydric alcohol content 22% by weight), which contained 20% or more of component (E). [Industrial applicability]

[0037] The present invention provides an oil-in-water acidic emulsion cosmetic characterized by containing a polymeric thickener such as S-lactoyl glutathione and carbomer, an aqueous emulsion of an acrylic acid polymer, and an acidic substance as essential components. According to the present invention, it is possible to provide an oil-in-water emulsion cosmetic that has excellent storage stability, spreads smoothly and refreshingly when applied, and provides a firm, non-sticky feeling after application.

Claims

1. An oil-in-water acidic emulsion cosmetic characterized by containing the following ingredients (A) to (D) and having a pH in the range of 4.5 to 5.

5. Ingredient (A): S-lactoyl glutathione Ingredient (B): Acrylic acid-based thickener Ingredients (C): Aqueous emulsion of acrylic polymer Component (D): Acidic substance

2. Furthermore, the oil-in-water acidic emulsion cosmetic according to claim 1 is characterized by containing 20% ​​by weight or more of component (E) polyhydric alcohol.

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