Oil-in-water emulsion composition

Abstract

To provide an oil-in-water type emulsion composition which achieves both a concentrated and rich texture and good elongation during application and has dry touch without stickiness even if it comes into contact with moisture again after application.SOLUTION: There is provided an oil-in-water type emulsion composition which comprises (A) an alkylene oxide derivative represented by the formula (1): R-O-(AO)a-[(PO)b / (EO)c]-H (the symbols in the formula are as defined in the description), (B) a fatty acid ester wax of an alcohol having 1 to 6 hydroxyl groups and a fatty acid having 16 to 22 carbon atoms, which has a melting point of 40 to 110°C and water, wherein the content of the component (A) is 0.1 to 10 mass% and the content of the component (B) is 0.2 to 15 mass% based on the whole composition.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an oil-in-water emulsion composition, and more particularly to an oil-in-water emulsion composition which has both a rich and full-bodied texture and good spreadability when applied, and which has a non-sticky, smooth feel even when in contact with water again after application. [Background technology]

[0002] Oil-in-water emulsion compositions are widely used in skin care cosmetics, hair cosmetics, and the like for the purpose of moisturizing the skin. It is generally important for emulsion cosmetics to have a feel that consumers find appealing when using them. A preferred feel when using them is, for example, a high level of moisturizing, and a rich, full-bodied texture that is easy to sense is desired. Known methods for achieving a rich feel include thickening with the addition of a thickener and using solid oils and fats as oily components. However, the addition of solid oils and fats can sometimes worsen the spreadability of the emulsion composition when spread and the stickiness after application, and various technologies have been developed to address these issues.

[0003] For example, Patent Document 1 discloses an emulsion composition that combines solid hydrocarbon oils, waxes, polyoxyethylene cetyl ether, and cationic polymers to achieve excellent spreadability on the skin, suppression of stickiness after application, and excellent moisturizing effects.

[0004] Furthermore, Patent Document 2 discloses an oil-in-water emulsion cosmetic that contains an acylamino acid salt, a paste-like or solid oil, a liquid oil, a polyalkylene glycol, and a polysaccharide, and has a mass ratio of (paste-like or solid oil) / liquid oil of 0.35 or more and 1.0 or less. It is reported that this cosmetic combines a rich and heavy texture with good spreadability, is compatible with the skin, and is less sticky after application.

[0005] However, in high humidity or sweaty conditions in summer, the applied emulsion composition may re-emulsify when mixed with sweat or moisture. Conventional techniques have had the problem of easily causing stickiness in such cases. Therefore, there has been a demand for an emulsion composition that is less likely to become sticky even when it comes into contact with moisture again after application and has a smooth, powdery feel. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-102258 [Patent Document 2] Japanese Patent Application Laid-Open No. 2018-16583 Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide an oil-in-water emulsion composition which has both a rich and full-bodied texture and good spreadability when applied, and which has a non-sticky, smooth feel even when in contact with water again after application. [Means for solving the problem]

[0008] As a result of extensive research, the present inventors have found that the above-mentioned object can be achieved by an oil-in-water emulsion composition containing the following components (A) and (B) in predetermined amounts. Based on this finding, the present invention is as follows. [1] The following components (A) and (B): (A) Formula (1) below: RO-(AO) a -[(PO) b / (EO) c ]-H (1) (In the formula, R is a linear or branched alkyl group having 12 to 36 carbon atoms; AO is an oxyalkylene group having 3 or 4 carbon atoms, PO is an oxypropylene group; EO is an oxyethylene group; [(PO) b / (EO) c ] is a polyoxyalkylene group in which PO and EO are randomly bonded, and a, b, and c are the average number of moles added per molecule of AO, PO, and EO, respectively, and are in the ranges of 1≦a≦40, 1≦b≦40, 1≦c≦80, 20≦(a+b+c), and 0.1≦(b+c) / (a+b+c)<1. and alkylene oxide derivatives represented by the formula: (B) a fatty acid ester wax having a melting point of 40 to 110°C and made of an alcohol having 1 to 6 hydroxyl groups and a fatty acid having 16 to 22 carbon atoms; and water and An oil-in-water emulsion composition, wherein the content of component (A) is 0.1 to 10 mass % and the content of component (B) is 0.2 to 15 mass % based on the total mass of the composition. [Effects of the Invention]

[0009] The oil-in-water emulsion composition of the present invention provides both a rich and full-bodied texture and good spreadability when applied, and provides a smooth, non-sticky feel even when in contact with water again after application. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described. In this specification, numerical ranges defined using the symbol "to" are inclusive of the numerical values ​​at both ends (upper and lower limits) of the symbol "to." For example, "2 to 5" means 2 or more and 5 or less.

[0011] The oil-in-water emulsion composition of the present invention (hereinafter sometimes abbreviated as "the composition of the present invention") contains components (A) and (B) and water. Hereinafter, the component (A) will be described in order.

[0012] [Component (A)] The component (A) used in the present invention is a compound represented by the formula (1): RO-(AO) a -[(PO) b / (EO) c ]-H (1) The component (A) is an alkylene oxide derivative represented by the formula: Only one type of component (A) may be used, or two or more types may be used in combination.

[0013] In formula (1), R represents a linear or branched alkyl group having 12 to 36 carbon atoms. If R has fewer than 12 carbon atoms, the stability of the composition of the present invention may decrease. R preferably has 18 or more carbon atoms, and more preferably has 20 or more carbon atoms. If R has more than 36 carbon atoms, the spreadability of the composition of the present invention may be impaired. R preferably has 32 or less carbon atoms, and more preferably has 26 or less carbon atoms.

[0014] Component (A) is usually produced using an alcohol, and R in formula (1) is derived from the alcohol (ROH) used in the production of component (A). Such alcohol is a linear or branched alcohol having 12 to 36 carbon atoms.

[0015] Examples of the alcohol (ROH) include linear alcohols such as dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, heptadecanol, octadecanol, nonadecanol, eicosanol, docosanol, tetracosanol, hexacosanol, octacosanol, triacosanol, and hexatriacosanol; and branched alcohols such as isotridecanol, 1-methylheptadecanol, 2-octyldecanol, 2-decyltetradecanol, 2-tetradecyloctadecanol, and 2-hexadecyleicosanol. One or more of these alcohols can be used in the preparation of component (A). Among these alcohols, branched alcohols are preferred, with isotridecanol, 1-methylheptadecanol, 2-octyldecanol, and 2-decyltetradecanol being more preferred, from the viewpoints of the good spreadability of the composition of the present invention during application and the non-sticky feel after application.

[0016] In formula (1), AO is an oxyalkylene group having 3 or 4 carbon atoms, PO is an oxypropylene group, and EO is an oxyethylene group. Examples of AO include an oxypropylene group and an oxybutylene group. When a is 2 or more, the two or more AO may be the same or different groups. When there are two or more types of AO, (AO) a AO may be added in either a random or block manner. AO is preferably an oxypropylene group.

[0017] In formula (1), a, b, and c are the average number of moles of AO, PO, and EO added per molecule, respectively. a is a number from 1 to 40. The upper limit of a is preferably 30, more preferably 20, and even more preferably 9. The lower limit of a is preferably 2, more preferably 3, and even more preferably 4. If a is too small or too large, the stability and non-sticky feel of the composition of the present invention may be impaired.

[0018] b is a number from 1 to 40. The upper limit of b is preferably 30, more preferably 20, and even more preferably 10. The lower limit of b is preferably 2, more preferably 3, and even more preferably 4. If b is too small or too large, the stability and non-sticky feel of the composition of the present invention may be impaired.

[0019] c is a number from 1 to 80. The upper limit of c is preferably 60, more preferably 40, and even more preferably 30. The lower limit of c is preferably 5, more preferably 10, and even more preferably 20. If c is too small or too large, the composition of the present invention may become sticky after application.

[0020] The sum (a+b+c) of the above a, b, and c is 20 or more, preferably 30 or more, and more preferably 35 or more. If (a+b+c) is too small, the stability of the composition of the present invention may decrease. Furthermore, from the viewpoint of the stability of the composition of the present invention, (a+b+c) is preferably 100 or less, more preferably 80 or less, even more preferably 50 or less, and particularly preferably 40 or less.

[0021] [(PO) b / (EO) c

[0049] indicates a polyoxyalkylene group in which PO and EO are bonded randomly, rather than in a block configuration. If EO and PO are bonded in a block configuration, the spreadability of the composition of the present invention may be poor when applied, or stickiness may occur after application.

[0022] Furthermore, when the number of carbon atoms in R is n, from the viewpoint of the stability of the composition of the present invention, it is preferably 30≦(2n+a)≦100, more preferably 30≦(2n+a)≦80, even more preferably 35≦(2n+a)≦80, and particularly preferably 40≦(2n+a)≦60.

[0023] For component (A), the ratio is 0.1≦(b+c) / (a+b+c)<1, preferably 0.3≦(b+c) / (a+b+c)≦0.97, more preferably 0.5≦(b+c) / (a+b+c)≦0.9, even more preferably 0.6≦(b+c) / (a+b+c)≦0.85, and particularly preferably 0.7≦(b+c) / (a+b+c)≦0.8. If (b+c) / (a+b+c) is too small, the composition of the present invention may not spread well when applied, or may become sticky after application.

[0024] Component (A) can be produced by a known method, for example, by addition-polymerizing an alkylene oxide with a linear or branched alkyl alcohol having 12 to 36 carbon atoms in the presence of an alkali catalyst at 50 to 160°C and 0.5 MPa (gauge pressure) or less, followed by addition-polymerizing a mixture of ethylene oxide and propylene oxide, neutralizing the mixture with an acid such as hydrochloric acid, phosphoric acid, or acetic acid, and then removing water and neutralized salts to obtain component (A).

[0025] The content of component (A) is 0.1 to 10% by mass based on the total mass of the composition of the present invention. If the content of component (A) is too low, the stability of the composition of the present invention will be poor, and if the content is too high, the composition of the present invention may become sticky after application. From this viewpoint, the content of component (A) is preferably 0.2 to 7% by mass, more preferably 0.5 to 5% by mass, based on the total mass of the composition of the present invention.

[0026] [Component (B)] Component (B) used in the present invention is a fatty acid ester wax having a melting point of 40 to 110° C., which is made from an alcohol having 1 to 6 hydroxyl groups and a fatty acid having 16 to 22 carbon atoms. Component (B) may be used alone or in combination of two or more types.

[0027] The melting point of component (B) is 40 to 110°C, preferably 60 to 100°C, and more preferably 70 to 95°C. If the melting point of component (B) is too low, the stability of the composition of the present invention may decrease, and the composition may feel sticky. If the melting point of component (B) is too high, the stability of the composition of the present invention may decrease, and the rich texture may be impaired.

[0028] The alcohol constituting component (B) is an alcohol having 1 to 6 hydroxyl groups. Examples of such alcohols include monohydric higher alcohols such as lauryl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, isostearyl alcohol, and behenyl alcohol; dihydric alcohols such as ethylene glycol and propylene glycol; trihydric alcohols such as glycerin, pentanetriol, and trimethylolpropane; tetrahydric alcohols such as pentaerythritol and hexanetetrol; pentahydric alcohols such as glucose; and hexahydric alcohols such as sorbitol, sorbitan, mannitol, and dipentaerythritol. Among these, polyhydric alcohols are preferred, and polyhydric alcohols having 3 to 6 hydroxyl groups are more preferred.

[0029] The fatty acid constituting component (B) is a fatty acid having a carbon number of 16 to 22. Examples of such fatty acids include palmitic acid, palmitoleic acid, stearic acid, oleic acid, isostearic acid, linoleic acid, ricinoleic acid and hydrogenated products thereof, arachidic acid, and behenic acid.

[0030] Examples of component (B) include stearyl stearate, behenyl behenate, pentaerythritol tetrabehenate, pentaerythritol tetrastearate, hexaglycerin octabehenate, hydrogenated castor oil, etc. Among these, hydrogenated castor oil, pentaerythritol tetrabehenate, and stearyl stearate are preferred, and hydrogenated castor oil and pentaerythritol tetrabehenate are more preferred.

[0031] The area of ​​component (B) contained in the range of 7°C lower and 3°C higher from the maximum peak temperature in a differential thermal curve, totaling 10°C, is preferably 80% or more of the total peak area, more preferably 90% or more of the total peak area. Use of such component (B) makes the feel of the composition of the present invention after application even more preferable.

[0032] The "maximum peak temperature" refers to the temperature at which the endotherm reaches its maximum in a differential thermal curve obtained by differential scanning calorimetry (DSC). The "total peak area" refers to the area enclosed by two lines on the differential thermal curve obtained by DSC, including the extension of the high-temperature baseline to the low-temperature side. The "area within a total of 10°C, extending 7°C below the maximum peak temperature and 3°C above the maximum peak temperature" refers to the area enclosed by four lines: the baseline of the differential thermal curve (including the extension of the high-temperature baseline of the differential thermal curve to the low-temperature side), the high-temperature perpendicular, the low-temperature perpendicular, and the differential thermal curve, when perpendicular lines (lines parallel to the vertical axis) are drawn from the temperature axis at 7°C below the maximum peak temperature and 3°C above the maximum peak temperature. For further details, see Japanese Patent Publication No. 4435434.

[0033] The content of component (B) is 0.2 to 15% by mass, and preferably 0.2 to 10% by mass, based on the total mass of the composition of the present invention. If the content of component (B) is too low, the smooth feeling of the composition of the present invention after application may be impaired, whereas if the content of component (B) is too high, the spreadability of the composition of the present invention upon application may be reduced.

[0034] From the viewpoint of good spreadability during application of the composition of the present invention and suppression of stickiness after application, the mass ratio of component (B) / component (A) is preferably 0.05 to 30, more preferably 0.05 to 15, and even more preferably 0.1 to 10.

[0035] (Other additives) The composition of the present invention may contain additives commonly used in cosmetics as appropriate, provided that the effects of the present invention are not impaired. Examples of such additives include oils, surfactants, moisturizers, thickeners, colorants, alcohols, UV protection agents, amino acids, vitamins, whitening agents, organic acids, inorganic salts, enzymes, antioxidants, stabilizers, preservatives, disinfectants, anti-inflammatory agents, skin activators, blood circulation promoters, antiseborrheic agents, anti-inflammatory agents, sequestering agents, pH adjusters, astringents, refreshing agents, fragrances, and pigments. [Example]

[0036] The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited thereto. Furthermore, "%" in the amounts of components described below means "% by mass."

[0037] <Synthesis Example 1: Synthesis of Component (A-1)> 100 g of isotridecanol and 2.0 g of potassium hydroxide as a catalyst were charged into an autoclave. The air in the autoclave was replaced with dry nitrogen, and the catalyst was dissolved at 140°C with stirring. Subsequently, 232 g of propylene oxide was added dropwise at 120°C and 0.2 to 0.5 MPa (gauge pressure) using a dropping device, and the mixture was stirred for 3 hours. Subsequently, a mixture of 528 g of ethylene oxide and 145 g of propylene oxide was added dropwise at 120°C and 0.2 to 0.5 MPa (gauge pressure) using a dropping device, and the mixture was stirred for 2 hours. The reaction mixture was then removed from the autoclave, neutralized with hydrochloric acid to a pH of 6 to 7, and treated at 100°C for 1 hour under a reduced pressure of -0.095 MPa (gauge pressure) to remove the water content. The mixture was then filtered to remove the salt formed after the treatment, yielding Component (A-1). In addition, the number average molecular weights of the ethylene oxide and propylene oxide adducts were determined from the hydroxyl value obtained by hydroxyl value measurement in accordance with JIS K1557-1, and the values ​​of a, b, and c in formula (1) were determined from the number average molecular weights.

[0038] <Synthesis Examples 2 to 4: Synthesis of Component (A-2), Component (A-3), Component (A'-1), and Component (A'-2)> Components (A-2), (A-3), (A'-1) and (A'-2) were obtained in the same manner as in Synthesis Example 1, except that the starting materials and the amounts of ethylene oxide and propylene oxide added were changed.

[0039] For components (A-1) to (A'-2), the starting materials, type of alkylene oxide, a, b, c, (a+b+c), (2n+a), and (b+c) / (a+b+c) are shown in Table 1. Components (A-1) to (A-3) are alkylene oxide derivatives that satisfy the requirements of the present invention, while components (A'-1) and (A'-2) are alkylene oxide derivatives that do not satisfy the requirements of the present invention.

[0040] [Table 1]

[0041] <Examples 1 to 9 and Comparative Examples 1 to 8> The components (i.e., component (A) or its corresponding component (A'), component (B) or its corresponding component (B'), the component common to the oil phase, and the component common to the water phase) were mixed in the types and amounts shown in Table 2 or 3, heated to 75 to 80°C, mixed at that temperature using a homomixer, and then cooled to obtain an oil-in-water emulsion composition.

[0042] Each composition obtained in the Examples and Comparative Examples was evaluated as follows for body when applied, spreadability when applied, stickiness after application, and smooth feeling when moisture is applied, and the results are shown in Tables 2 and 3. In Tables 2 and 3, the melting point of the component (B) or (B') used is also shown next to the name of that compound.

[0043] <Body when applied> Ten healthy panelists applied 0.1 g of each composition of the Examples and Comparative Examples to their forearms. The texture of the composition upon application was evaluated on a three-point scale according to the following criteria. The total score of the 10 panelists was calculated and evaluated according to the following criteria. (Grading criteria) 3 points: The texture is rich when applied. 2 points: The texture is slightly rich when applied. 1 point: The texture lacks body when applied. (Evaluation criteria) ◎: 25 points or more ○: 20 points or more, less than 25 points △: 15 points or more, less than 20 points ×: Less than 15 points

[0044] <Good spreadability when applied> Ten healthy panelists applied 0.1 g of each composition of the Examples and Comparative Examples to their forearms. The spread of the composition upon application was evaluated on a three-point scale based on the following criteria. The total score of the 10 panelists was calculated and evaluated according to the following criteria. (Grading criteria) 3 points: Spreads well when applied. 2 points: Spreads fairly well when applied. 1 point: Poor spread when applied. (Evaluation criteria) ◎: 25 points or more ○: 20 points or more, less than 25 points △: 15 points or more, less than 20 points ×: Less than 15 points

[0045] <Sticky after application> Ten healthy panelists applied 0.1 g of each composition of the Examples and Comparative Examples to their forearms. After 5 minutes, the stickiness of the skin after application was evaluated on a three-point scale according to the following criteria. The total score of the 10 panelists was calculated and evaluated according to the following criteria. (Grading criteria) 3 points: No stickiness on skin after application. 2 points: Skin feels slightly sticky when applied. 1 point: Skin feels sticky when applied. (Evaluation criteria) ◎: 25 points or more ○: 20 points or more, less than 25 points △: 15 points or more, less than 20 points ×: Less than 15 points

[0046] <Smooth feeling when moisture adheres> Ten healthy panelists applied 0.1 g of each composition of the Examples and Comparative Examples to their forearms. A 0.5% aqueous solution of sodium chloride, simulating sweat, was placed in a spray container and sprayed once onto the skin to which the composition had been applied. The feel after spraying was evaluated on a three-point scale based on the following rating scale. The total score of the 10 panelists was calculated and evaluated according to the following rating scale. (Grading criteria) 3 points: Feels smooth when wet. 2 points: When moisture is applied, the feel is somewhat dry. 1 point: When moisture gets on it, it doesn't feel smooth. (Evaluation criteria) ◎: 25 points or more ○: 20 points or more, less than 25 points △: 15 points or more, less than 20 points ×: Less than 15 points

[0047] [Table 2]

[0048] [Table 3]

[0049] As is clear from Table 2, the compositions of Examples 1 to 9 all had good body when applied, good spreadability when applied, stickiness after application, and a smooth feel when moisture was applied. In contrast, as is clear from Table 3, the compositions of Comparative Examples 1 to 8 were not good in any of the following: richness upon application, good spreadability upon application, stickiness after application, or a smooth feeling when moisture was attached. [Industrial Applicability]

[0050] The composition of the present invention has a rich and full-bodied texture and good spreadability when applied, and has a smooth and non-sticky feel even when it comes into contact with water again after application, and can be used as a preparation such as a cream or emulsion.

Claims

[Claim 1] The following components (A) and (B): (A) The following formula (1): R-O-(AO) ａ -[ (PO) ｂ / (EO) ｃ ]-H ・・・(1) (In the formula, R is a linear or branched alkyl group having 12 to 36 carbon atoms; AO is an oxyalkylene group having 3 or 4 carbon atoms; PO is an oxypropylene group; EO is an oxyethylene group; [(PO) ｂ / (EO) ｃ ] is a polyoxyalkylene group in which PO and EO are randomly bonded, and a, b, and c are the average numbers of moles of AO, PO, and EO added per molecule, respectively, and are within the ranges of 1≦a≦40, 1≦b≦40, 1≦c≦80, 20≦(a+b+c), and 0.1≦(b+c) / (a+b+c)<1. and alkylene oxide derivatives represented by the formula: (B) a fatty acid ester wax having a melting point of 40 to 110°C and made from an alcohol having 1 to 6 hydroxyl groups and a fatty acid having 16 to 22 carbon atoms; and water and An oil-in-water emulsion composition, wherein the content of component (A) is 0.1 to 10 mass % and the content of component (B) is 0.2 to 15 mass % based on the total mass of the composition.

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