Oil-in-water emulsion cosmetics

Abstract

To provide an oil-in-water emulsion cosmetic with improved emulsion stability and reduced stickiness of nicotinamide.SOLUTION: An oil-in-water emulsion cosmetic comprises component (A), component (B), and component (C), wherein the component (A) is nicotinamide, the component (B) is a bivalent alcohol, and the component (C) is polyglycerol fatty acid ester; the content of the component (A) is 1 mass% or more and 10 mass% or less relative to the total amount of the oil-in-water emulsion cosmetic, the component (C) has an HLB value of 7 or more and 14 or less, and the content of the component (C) is 0.5 mass% or more and 5.0 mass% or less relative to the total amount of the oil-in-water emulsion cosmetic.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to an oil-in-water emulsion cosmetic containing nicotinamide. [Background technology]

[0002] Nicotinamide has attracted attention as an ingredient that improves age-related skin conditions such as wrinkles, fine lines, uneven skin tone, and firmness. One example of an oil-in-water emulsion cosmetic containing nicotinamide contains a branched-chain hydrocarbon with a weight-average molecular weight of 100 to 1,000, such as isododecane or isohexadecane, thereby (a) reducing stickiness caused by nicotinamide (see, for example, Patent Document 1). Another example of an oil-in-water emulsion cosmetic that (a) reduces stickiness caused by nicotinamide contains a polyglycerol fatty acid ester with an HLB of 5.5 or less and an anionic surfactant (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2003-502435 [Patent Document 2] Patent No. 6921288 Summary of the Invention [Problem to be solved by the invention]

[0004] On the other hand, oil-in-water emulsion cosmetics containing nicotinamide are required to (a) suppress stickiness caused by nicotinamide, as well as (b) improve the emulsion stability of the oil-in-water emulsion cosmetics. As mentioned above, a composition containing a polyglycerol fatty acid ester having an HLB of 5.5 or less and an anionic surfactant can (a) suppress stickiness caused by nicotinamide, but (b) cannot be said to provide sufficient emulsion stability of the oil-in-water emulsion cosmetics. [Means for solving the problem]

[0005] The oil-in-water emulsion cosmetic that solves the above problems is an oil-in-water emulsion cosmetic containing component (A), component (B), and component (C). Component (A) is nicotinamide, component (B) is a dihydric alcohol, and component (C) is a polyglycerol fatty acid ester. The blending amount of component (A) is from 1% to 10% by mass, based on the total amount of the oil-in-water emulsion cosmetic, the blending amount of component (B) is from 25% to 25% by mass, based on the total amount of the oil-in-water emulsion cosmetic, the HLB value of component (C) is from 7 to 14, and the blending amount of component (C) is from 0.5% to 5.0% by mass, based on the total amount of the oil-in-water emulsion cosmetic.

[0006] The oil-in-water emulsion cosmetic further contains component (D) and component (E), where component (D) is an N-long-chain acyl amino acid surfactant and component (E) may be a higher alcohol. The blending amount of component (D) is 0.05% by mass or more and 5.0% by mass or less of the total amount of the oil-in-water emulsion cosmetic.

[0007] The oil-in-water emulsion cosmetic further contains a component (F), which may be dimethicone. The amount of component (F) is 0.2% by mass or more and 8.0% by mass or less relative to the total amount of the oil-in-water emulsion cosmetic, and the viscosity of component (F) is 15 mPa s or more and 150 mPa s or less.

[0008] The oil-in-water emulsion cosmetic does not contain phenoxyethanol or ethanol, and further contains component (G), which is an alkylglycerol, and the blending amount of component (G) may be 0.05% by mass or more and 0.15% by mass or less. [Effects of the Invention]

[0009] The oil-in-water emulsion cosmetic (a) reduces stickiness caused by nicotinamide, and (b) improves the emulsion stability of the oil-in-water emulsion cosmetic. DETAILED DESCRIPTION OF THE INVENTION

[0010] The oil-in-water emulsion cosmetic will be described below. The oil-in-water emulsion cosmetic contains component (A), component (B), and component (C). The oil-in-water emulsion cosmetic may contain each of component (D), component (E), component (F), and component (G) independently. In addition to components (A) to (G), the oil-in-water emulsion cosmetic may contain a moisturizer, amino acid, pH adjuster, vitamins, antioxidant, water-soluble polymer, and fragrance.

[0011] Ingredient (A): Nicotinamide Ingredient (B): Dihydric alcohol Ingredient (C): Polyglycerin fatty acid ester Ingredient (D): N-long-chain acyl amino acid surfactant Ingredient (E): High-grade alcohol Ingredient (F): Dimethicone Ingredient (G): Alkylglycerol

[0012] One form of the oil-in-water emulsion cosmetic exhibits the following effects (i), (ii), and (iii): Another form of the oil-in-water emulsion cosmetic exhibits the following effect (iv) in addition to the following effects (i) to (iii). Effect (i): Reduces stickiness on the skin. Effect (ii): Increases firmness and elasticity of the skin. Effect (iii): Excellent emulsion stability. ·Effect (iv): Reduces irritation.

[0013] [Component (A): Nicotinamide] Nicotinamide is pyridine-3-carboxylic acid amide. Examples of nicotinamide include niacinamide USP PC (manufactured by Lonza Japan) and nicotinamide (manufactured by DSM).

[0014] When the oil-in-water emulsion cosmetic is required to achieve effect (ii), the amount of nicotinamide blended is preferably 1.0% by mass or more relative to the total amount of the oil-in-water emulsion cosmetic.When the oil-in-water emulsion cosmetic is required to achieve effect (i), the amount of nicotinamide blended is preferably 10.0% by mass or less.

[0015] When the oil-in-water emulsion cosmetic is required to further enhance effect (ii), the amount of nicotinamide blended is preferably 3.0% by mass or more, and more preferably 4.0% by mass or more, of the total amount of the oil-in-water emulsion cosmetic.

[0016] When the oil-in-water emulsion cosmetic is required to further enhance effect (i), the amount of nicotinamide blended is preferably 8.0% by mass or less, and more preferably 7.0% by mass or less, of the total amount of the oil-in-water emulsion cosmetic.

[0017] [Component (B): Dihydric alcohol] The dihydric alcohol is an aliphatic dihydric alcohol having a carbon number of 3 or more and 5 or less. An example of the dihydric alcohol may be a straight-chain aliphatic alcohol or a branched aliphatic alcohol.

[0018] Dihydric alcohols include 1,3-butylene glycol, isopentane-2,3-diol, 1,2-pentanediol, dipropylene glycol, and propanediol. Examples of 1,3-butylene glycol include 1,3-butylene glycol-UK (manufactured by Daicel Corporation), 1,3-butylene glycol-P (manufactured by Neochem KH Co., Ltd.), and Hysugarcane BG-R (manufactured by Koyo Alcohol Co., Ltd.). An example of isopentane-2,3-diol is isoprenglycol-S (manufactured by Kuraray Co., Ltd.). An example of dipropylene glycol is dipropylene glycol Lo+ (manufactured by Dow Chemical Co., Ltd.). An example of propanediol is ZEMEA SELECT PROPANEDIOL (manufactured by DuPont Co., Ltd.).

[0019] When the oil-in-water emulsion cosmetic is required to achieve the effect (i), the blending amount of the dihydric alcohol is 25% by mass or less based on the total amount of the oil-in-water emulsion cosmetic. When the oil-in-water emulsion cosmetic is required to further achieve the effect (ii), the blending amount of the dihydric alcohol is 6.0% by mass or more based on the total amount of the oil-in-water emulsion cosmetic.

[0020] When the oil-in-water emulsion cosmetic is required to achieve the effects (i) and (iii), the blending amount of the dihydric alcohol is 20.0 mass % or less. When the oil-in-water emulsion cosmetic is required to further enhance effect (ii), the blending amount of the dihydric alcohol is preferably 8% by mass or more, and more preferably 9% by mass or more, based on the total amount of the oil-in-water emulsion cosmetic.

[0021] When the oil-in-water emulsion cosmetic is required to have enhanced effects (i) and (iii), the amount of dihydric alcohol blended is preferably 15% by mass or less, and more preferably 12% by mass or less, of the total amount of the oil-in-water emulsion cosmetic.

[0022] [Component (C): Polyglycerin fatty acid ester] Polyglycerol fatty acid esters are esters of polyglycerol with linear unsaturated fatty acids or branched unsaturated fatty acids. The degree of polymerization of polyglycerol used to produce the polyglycerol fatty acid ester is 4 to 12. The number of carbon atoms of the unsaturated fatty acid used to produce the polyglycerol fatty acid ester is 12 to 18. Examples of polyglycerol fatty acid esters are polyglyceryl-6 myristate, polyglyceryl-6 stearate, and polyglyceryl-10 isostearate. Examples of polyglycerol fatty acid esters are NIKKOL Hexaglyn 1-M (manufactured by Nikko Chemicals Co., Ltd.), NIKKOL Hexaglyn 1-L (manufactured by Nikko Chemicals Co., Ltd.), and S-Face IS-1001P (manufactured by Sakamoto Pharmaceutical Co., Ltd.).

[0023] When effects (i) and (iii) are required for an oil-in-water emulsion cosmetic, the HLB value of the polyglycerol fatty acid ester is 7 or higher. When effects (i) and (iii) are required for an oil-in-water emulsion cosmetic, the HLB value of the polyglycerol fatty acid ester is 14 or lower. When the effectiveness of effects (i) and (iii) is further required for an oil-in-water emulsion cosmetic, the HLB value of the polyglycerol fatty acid ester is 8 or higher. When effects (i) and (iii) are required for an oil-in-water emulsion cosmetic, the HLB value of the polyglycerol fatty acid ester is 12 or lower.

[0024] When the oil-in-water emulsion cosmetic is required to achieve effect (iii), the blending amount of polyglycerol fatty acid ester is 0.5% by mass or more relative to the total amount of the oil-in-water emulsion cosmetic. When the oil-in-water emulsion cosmetic is required to enhance effect (i), the blending amount of polyglycerol fatty acid ester is preferably 1.0% by mass or more, and more preferably 1.7% by mass or more, relative to the total amount of the oil-in-water emulsion cosmetic.

[0025] When the oil-in-water emulsion cosmetic is required to achieve effect (i), the blending amount of polyglycerol fatty acid ester is 6.2% by mass or less relative to the total amount of the oil-in-water emulsion cosmetic. When the oil-in-water emulsion cosmetic is required to enhance effect (i), the blending amount of polyglycerol fatty acid ester is preferably 4.0% by mass or less, and more preferably 3.5% by mass or less, relative to the total amount of the oil-in-water emulsion cosmetic.

[0026] [Component (D): N-long-chain acyl amino acid surfactant] N-long-chain acyl amino acid surfactants are surfactants having primary to tertiary amino groups and carboxyl groups. N-long-chain acyl amino acid surfactants include N-acyl amino acid surfactants, amide amino acid surfactants which are imidazoline surfactants, and aminodiacetic acid surfactants. N-acyl amino acid surfactants include anionic surfactants.

[0027] The anionic surfactant is a condensation compound of an amino acid, including D-amino acids and L-amino acids, with a higher fatty acid, or a condensation compound of an amino acid salt with a higher fatty acid. An example of the amino acid is at least one selected from the group consisting of N-methylglycine, N-methyl-β-alanine, glutamic acid, aspartic acid, sarcosine, valine, serine, phenylalanine, and methyltaurine. An example of the amino acid salt is at least one selected from the group consisting of sodium salts, potassium salts, triethanolamine salts, and monoethanolamine salts. An example of the higher fatty acid is at least one selected from the group consisting of lauric acid, coconut oil fatty acid, palmitic acid, and myristic acid.

[0028] An example of an anionic surfactant is a condensation compound of a natural fatty acid having from 12 to 18 carbon atoms with L-glutamic acid, or a condensation compound of a natural fatty acid having from 12 to 18 carbon atoms with L-glutamic acid salt. An example of an anionic surfactant is a condensation compound of a natural fatty acid having from 12 to 18 carbon atoms with L-methyl taurine, or a condensation compound of a natural fatty acid having from 12 to 18 carbon atoms with L-methyl taurine salt. Examples of anionic surfactants are sodium lauroyl glutamate, sodium myristoyl glutamate, sodium stearoyl glutamate, sodium cocoyl methyl taurate, and sodium stearoyl methyl taurate.

[0029] An example of sodium stearoyl glutamate is Aminosoft HS-11P(F) (manufactured by Ajinomoto Co., Inc.). An example of sodium myristoyl glutamate is Aminosurfactant (registered trademark) AMMS-P1 (manufactured by Asahi Kasei Finechem Co., Ltd.). An example of sodium lauroyl glutamate is Aminosurfactant (registered trademark) ALMS-P1 (manufactured by Asahi Kasei Finechem Co., Ltd.). An example of sodium stearoyl glutamate is NIKKOL SMT (manufactured by Nikko Chemicals Co., Ltd.). An example of sodium cocoyl methyl taurate is Diapon K-SF (manufactured by NOF Corporation).

[0030] When the oil-in-water emulsion cosmetic is required to achieve effect (iii), the amount of the N-long-chain acyl amino acid surfactant blended is preferably 0.05% by mass or more, and more preferably 0.3% by mass or more, of the total amount of the oil-in-water emulsion cosmetic.

[0031] When the oil-in-water emulsion cosmetic is required to achieve the effects (i) and (iv), the amount of N-long-chain acyl amino acid surfactant blended is preferably 5.0% by mass or less, and more preferably 1.5% by mass or less, of the total amount of the oil-in-water emulsion cosmetic.

[0032] [Ingredient (E): Higher alcohol] The higher alcohol is preferably a straight-chain or branched, saturated or unsaturated higher alcohol having 12 or more carbon atoms. Examples of straight-chain higher alcohols include lauryl alcohol, cetyl alcohol, stearyl alcohol, behenyl alcohol, myristyl alcohol, oleyl alcohol, and cetostearyl alcohol. Examples of branched-chain higher alcohols include monostearyl glycerin ether (batyl alcohol), 2-decyltetradecinol, lanolin alcohol, cholesterol, phytosterol, hexyl dodecanol, isostearyl alcohol, and octyl dodecanol. An example of behenyl alcohol is behenyl alcohol (manufactured by Higher Alcohol Co., Ltd.). An example of monostearyl glycerin ether (batyl alcohol) is NIKKOL Batyl Alcohol EX (manufactured by Nikko Chemicals Co., Ltd.).

[0033] When the oil-in-water emulsion cosmetic is required to achieve effect (iii), the amount of higher alcohol is preferably greater than 0% by mass relative to the total amount of the oil-in-water emulsion cosmetic. When the oil-in-water emulsion cosmetic is required to further enhance effect (iii), the amount of higher alcohol is preferably 1.0% to 6.5% by mass relative to the total amount of the oil-in-water emulsion cosmetic. It is even more preferably 2.0% to 5.0% by mass. Furthermore, the types of higher alcohols are preferably behenyl alcohol and monostearyl glycerin ether (batyl alcohol). It is even more preferable that the amount of batyl alcohol is 0.1% to 0.5% by mass relative to the total amount of the oil-in-water emulsion cosmetic. It is even more preferable that the amount of behenyl alcohol is 1.0% to 6.5% by mass relative to the total amount of the oil-in-water emulsion cosmetic. It is even more preferable that the amount of behenyl alcohol is 1.0% to 3.0% by mass.

[0034] [Ingredient (F): Dimethicone] Examples of dimethicone include DOWSIL SH 200 C Fluid 20 cSt (manufactured by Dow-Toray), OWSIL SH 200 C Fluid 30 cs (manufactured by Dow-Toray), OWSIL SH 200 C Fluid 50 cs (manufactured by Dow-Toray), and OWSIL SH 200 C Fluid 100 cs (manufactured by Dow-Toray).

[0035] When the oil-in-water emulsion cosmetic is required to achieve the effects (i) and (iii), the amount of dimethicone blended is preferably from 0.2% to 8.0% by mass of the total amount of the oil-in-water emulsion cosmetic, and the viscosity of dimethicone is preferably from 15 mPa·s to 150 mPa·s.

[0036] When an oil-in-water emulsion cosmetic is required to enhance effect (i), the amount of dimethicone blended is preferably 3% by mass or less relative to the total amount of the oil-in-water emulsion cosmetic, and the viscosity of the dimethicone is preferably 100 mPa·s or less. When an oil-in-water emulsion cosmetic is required to enhance effects (i) and (iii), the amount of dimethicone blended is more preferably 3% by mass or less relative to the total amount of the oil-in-water emulsion cosmetic, and 60 mPa·s or less. When an oil-in-water emulsion cosmetic is required to further enhance effects (i) and (iii), the amount of dimethicone blended is preferably 1% by mass or more and 3% by mass or less relative to the total amount of the oil-in-water emulsion cosmetic, and the viscosity of the dimethicone is preferably 15 mPa·s or more and 60 mPa·s or less.

[0037] [Component (G): Alkylglycerol] The oil-in-water emulsion cosmetic does not contain a preservative that is at least one of phenoxyethanol and ethanol, and may contain an alkylglycerol. The alkyl chain of the alkylglycerol is a straight or branched chain having 6 or more carbon atoms. Examples of alkylglycerols are hexylglycerin, ethylhexylglycerin, and cyclohexylglycerin. An example of ethylhexylglycerin is Sensiva SC 50 (manufactured by Ashland). An example of hexylglycerin is Adekanol NHG (manufactured by ADEKA). An example of cyclohexylglycerin is Adekanol CHG (manufactured by ADEKA).

[0038] When the effectiveness of effect (iv) is required for an oil-in-water emulsion cosmetic, it is preferable that the oil-in-water emulsion cosmetic does not contain phenoxyethanol or ethanol, but contains ethylhexylglycerin, an example of an alkylglycerol. When an enhancement of effect (iv) is required for an oil-in-water emulsion cosmetic, the blending amount of ethylhexylglycerin is preferably 0.1% by mass or more and 1% by mass or less of the total amount of the oil-in-water emulsion cosmetic.

[0039] [Test example] The ingredients contained in the oil-in-water emulsion cosmetics of Test Examples 1 to 13 are shown in Table 1. Table 2 shows the ingredients contained in the oil-in-water emulsion cosmetics of Test Examples 14 to 24. The ingredients contained in the oil-in-water emulsion cosmetics of Test Examples 31 to 38 are shown in Table 3. Table 4 shows the ingredients contained in the oil-in-water emulsion cosmetics of Test Examples 39 to 44.

[0040] In preparing the oil-in-water emulsion cosmetics of each test example, first, the oil phase components and the aqueous phase components of the ingredients shown in Tables 1 to 4 were separately heated and dissolved at 70° C. to 80° C. Next, the oil phase component was added to the aqueous phase component after heating and dissolution, and the aqueous phase component to which the oil phase component had been added was emulsified by stirring in a homomixer, thereby preparing an oil-in-water emulsion cosmetic.

[0041] The oil-in-water emulsion cosmetics of each test example were evaluated for (a) stickiness, (b) firmness, (c) emulsion stability, and (d) irritation.

[0042] [Table 1]

[0043] [Table 2]

[0044] [Table 3]

[0045] [Table 4] (sensory evaluation) Ten expert panelists were selected from women aged 20 to 49 who had received sensory evaluation training and were able to perform evaluations according to a set of criteria. The selected expert panelists evaluated each test example oil-in-water emulsion cosmetic product based on the absolute evaluation criteria for (a) the degree of stickiness, (b) the degree of firmness or elasticity of the skin, and (d) the degree of irritation felt when applied to their own skin. The total scores of the 10 expert panelists were then calculated for each test example, and the rating of the test example was determined based on each of the four-level rating criteria. The absolute evaluation criteria and four-level rating criteria for each evaluation are shown below.

[0046] (a) Stickiness evaluation Absolute evaluation criteria (Score) :(Evaluation) 5 points: No stickiness 4 points: Almost no stickiness 3 points: Feels slightly sticky 2 points: Sticky feeling 1 point: Very sticky 4-level evaluation criteria (Judgment): (Average score) ◎ Very good: Over 4 points Good: More than 3 points and less than 4 points △ Slightly poor: More than 2 points and less than 3 points × Defective: 2 points or less

[0047] (b) Hari evaluation Absolute evaluation criteria (Score) :(Evaluation) 6 points: Skin feels very firm or elastic 5 points: Skin feels firm and elastic 4 points: Skin feels slightly firmer or more elastic 3 points: Average 2 points: Skin does not feel very firm or elastic 1 point: Skin does not feel firm or elastic 4-level evaluation criteria (Judgment): (Average score) ◎ Very good: Over 5 points ○ Good: Over 3.5 points and 5 points or less △ Slightly poor: More than 2 points and less than 3.5 points × Defective: 2 points or less

[0048] (d) Irritation evaluation Absolute evaluation criteria (Score) :(Evaluation) 1 point: No irritation 0 points: Feels irritated 4-level evaluation criteria (Judgment): (Total score) ◎ Very good: Over 7 points Good: More than 4 points and less than 7 points △ Slightly poor: More than 1 point and less than 4 points × Defective: 1 point or less

[0049] (c) Emulsion stability evaluation 50 ml of the oil-in-water emulsion cosmetic was placed in a 60 ml glass vial, and the sealed glass vial was then placed in a thermostatic bath at 50°C. One month after sealing, the state of the emulsion particles in the oil-in-water emulsion cosmetic was observed using an optical microscope. The relationship between the observation results of the emulsion particles and the evaluation indices shown in Tables 1 to 4 is shown below.

[0050] (Evaluation index): (Observation results) ◎ Very good: No coalescence of emulsified particles observed Good: Slight coalescence of emulsified particles observed △ Slightly poor: Coalescence of emulsion particles was observed, and the size of emulsion particles was more than twice the size when sealed. × Poor: Coalescence of emulsified particles is observed, and the size of the emulsified particles is four times or more the size when sealed.

[0051] [(A) Nicotinamide content and stickiness] The stickiness of Test Example 6 and Test Example 41 was recognized as "△" and "◯", respectively. Furthermore, the stickiness of Test Example 1, Test Example 31, and Test Example 40 was recognized as "◎", respectively. From this, it was recognized that while the incorporation of nicotinamide increases stickiness, if the incorporation amount of nicotinamide is 1.0 mass% or more and 10.0 mass% or less, effect (i) can be obtained by adjusting the incorporation ratio of polyglycerol fatty acid ester.

[0052] [(A) Nicotinamide content and skin firmness] The skin firmness of Test Example 6 and Test Example 41 was recognized as "◎", "×", and "◯", respectively. From this, it was recognized that if the blending amount of nicotinamide is 1.0 mass% or more, effect (ii) can be obtained, and if the blending amount of nicotinamide is 3.0 mass% or more, effect (ii) can be further enhanced.

[0053] [(B) Dihydric alcohol content and stickiness] While the stickiness of Test Examples 1 to 4 was rated as either "△" or "◎," the stickiness of Test Example 34 out of Test Examples 33 and 34 was rated as "×." From this, it was recognized that a dihydric alcohol content of 25% by mass or less is a condition for obtaining effect (i) while also obtaining effect (ii) by nicotinamide. Furthermore, it was recognized that a dihydric alcohol content of 20% by mass or less is a condition for enhancing the effectiveness of effect (i).

[0054] While the firmness of Test Examples 1 to 4 was either "△" or "◎", the firmness of Test Example 33 out of Test Examples 33 and 34 was "×". From this, it was recognized that a blending amount of dihydric alcohol of 6.0% by mass or more is a condition for obtaining effect (ii). Furthermore, a blending amount of dihydric alcohol of 6.0% by mass or more and 20.0% by mass or less is a condition for enhancing the effectiveness of effect (i) and obtaining effect (ii).

[0055] [(C)HLB and emulsion stability] The emulsion stability of Test Examples 1, 5 to 7, 39, and 42 was rated as either "△", "◯", or "◎", while the emulsion stability of Test Examples 37 and 38 was rated as "×". From this, it was recognized that the HLB value of the polyglycerol fatty acid ester being 7 or more and 14 or less is a condition for achieving effect (iii). Furthermore, from a comparison of Test Examples 1, 6, 7, 39, and 42 with Test Examples 37 and 38, it was recognized that the HLB value of the polyglycerol fatty acid ester being 8 or more and 12 or less is a condition for enhancing the effectiveness of effect (iii).

[0056] The emulsion stability of Test Examples 1, 5 to 7, 39, and 42 was either "△", "◯", or "◎", while the emulsion stability of Test Example 35 out of Test Examples 35 and 36 was "×". From this, it was found that a blending amount of polyglycerol fatty acid ester of 0.5 mass% or more is a condition for obtaining effect (iii).

[0057] The stickiness of Test Examples 1, 5 to 7, 39, and 42 was either "△" or "◎", while the stickiness of Test Example 36 out of Test Examples 35 and 36 was "×". From this, it was found that a blending amount of polyglycerol fatty acid ester of 6.2 mass% or less is a condition for obtaining effect (i).

[0058] From these findings, it was recognized that the conditions for obtaining effects (i) and (iii) are that the HLB of the polyglycerol fatty acid ester is 7 or more and 14 or less, and the blending amount of the polyglycerol fatty acid ester is 0.5% by mass or more and 6.2% by mass or less.

[0059] Furthermore, Test Examples 1 and 7 were rated as excellent in terms of stickiness and emulsion stability, while Test Example 5 was rated as fair in terms of emulsion stability and Test Example 6 was rated as fair in terms of stickiness. Therefore, it was determined that a blending amount of polyglycerol fatty acid ester of 1.0% by mass or less and 4.0% by mass or less is a range in which both effects (i) and (iii) are easily achieved. Furthermore, it was determined that a blending amount of polyglycerol fatty acid ester of 1.7% by mass or less and 3.5% by mass or less enhances the effectiveness of achieving both effects (i) and (iii).

[0060] [(D) Surfactant content and emulsion stability] The emulsion stability of Test Examples 1, 8, and 9 was either "good" or "good", while the emulsion stability of Test Example 15 was "fair". It was found that the stickiness of Test Examples 1 and 8 was rated as "Excellent", while the stickiness of Test Example 16 was rated as "Average".

[0061] From these findings, it was found that a blending amount of N-long-chain acyl amino acid surfactant of 0.05% by mass or more and 5.0% by mass or more makes it possible to adjust effect (i) and effect (iii) in a trade-off relationship in which increasing one decreases the other.

[0062] Furthermore, it was recognized that a blending amount of the N-long-chain acyl amino acid surfactant of 0.3% by mass or more is a condition for further enhancing effect (iii). Furthermore, it was recognized that a blending amount of N-long-chain acyl amino acid surfactant of 1.5% by mass or less is a condition for further enhancing effect (i), and that a blending amount of N-long-chain acyl amino acid surfactant of 1.0% by mass or less is a condition for enhancing the effectiveness of enhancing effect (i), and that a blending amount of N-long-chain acyl amino acid surfactant of 0.8% by mass or less is a condition for further enhancing the effectiveness of enhancing effect (i).

[0063] From these findings, it was also recognized that the conditions for achieving both effects (i) and (iii) were that the N-long-chain acyl amino acid surfactant was sodium N-stearoyl glutamate and its blending amount was 0.3% by mass or more and 1.5% by mass or less. Furthermore, the conditions for achieving both effects (i) and (iii) were increased by the fact that the N-long-chain acyl amino acid surfactant was sodium N-stearoyl glutamate and its blending amount was 0.3% by mass or more and 1.0% by mass or less. Furthermore, the conditions for achieving both effects (i) and (iii) were increased by the fact that the N-long-chain acyl amino acid surfactant was sodium N-stearoyl glutamate and its blending amount was 0.8% by mass or less.

[0064] [(E) Amount of higher alcohol and emulsion stability] The emulsion stability of Test Example 1 was rated as "◎", while the emulsion stability of Test Example 17 was rated as "△". From this, it was determined that a blending amount of higher alcohol of 1.0% by mass or more and 10.0% by mass or less increases the likelihood of obtaining effect (iii), and that a blending amount of higher alcohol of 1.2% by mass or more and 2.3% by mass or less is a condition for increasing the effectiveness of enhancing effect (iii).

[0065] [(F) Dimethicone content, emulsion stability, stickiness] The emulsion stability of Test Examples 1, 12, 14, 18, and 20 was either "good" or "good", while the emulsion stability of Test Examples 13, 19, and 21 was "fair". It was observed that the stickiness of Test Examples 1, 13, and 14 was rated as "Excellent", while the stickiness of Test Examples 11, and 18 to 21 was rated as "Fair".

[0066] From these findings, it was found that when the viscosity of dimethicone is 15 mPa·s or more and 150 mPa·s or less, and the amount of dimethicone is 0.2 mass% or more and 8.0 mass% or less, it is possible to adjust effect (i) and effect (iii) in a trade-off relationship in which increasing one decreases the other.

[0067] Furthermore, it was recognized that the conditions for enhancing effect (i) were that the viscosity of dimethicone was 15 mPa·s or more and 150 mPa·s or less, and that the amount of dimethicone blended was 1.1 mass% or more and 6.2 mass% or less.

[0068] Furthermore, it was recognized that a dimethicone content of 3.0% by mass or less was a condition for further enhancing effect (iii). From the above, it was recognized that the viscosity of dimethicone being 15 mPa·s or more and 150 mPa·s or less, and the amount of dimethicone being 1.1 mass% or more and 3.0 mass% or less, are conditions for enhancing the effectiveness of achieving both effects (i) and (iii).

[0069] Furthermore, it was recognized that the viscosity of dimethicone being 15 mPa·s or more and 100 mPa·s or less, and the amount of dimethicone being 1.1% by mass or more and 3.0% by mass or less, are conditions for further enhancing the effectiveness of achieving both effects (i) and (iii).

[0070] Furthermore, it was recognized that the viscosity of dimethicone being 15 mPa·s or more and 100 mPa·s or less, and the amount of dimethicone being 1.5 mass% or more and 2.5 mass% or less, are conditions that further enhance the effectiveness of achieving both effects (i) and (iii).

[0071] [(G) Alkylglycerols and Irritation] The irritation of Test Example 1 was rated as "◎", while the irritation of Test Examples 22 and 23 was rated as "△". From this, it was determined that not containing phenoxyethanol and ethanol and containing alkylglycerol in an amount of 0.05% by mass or more and 0.15% by mass or less are conditions for enhancing effect (iv).

[0072] Specific formulation examples of oil-in-water emulsion cosmetics are shown below. [Prescription example] Ingredients Amount (mass%) Nicotinamide 5.00 1,3-butylene glycol 4.00 Dipropylene glycol 4.00 Pentylene glycol 2.00 Polyglyceryl-6 Stearate 1.25 Sodium stearoyl glutamate 0.30 Behenyl alcohol 4.00 Batyl alcohol 0.30 Dimethicone (20mPa·S) 1.00 Ethylhexylglycerin 0.10 Squalane 9.00 Phytosteryl / Octyldodecyl Lauroyl Glutamate 1.00 Isohexadecane 0.225 Tocopherol 0.02 Glycerin 7.00 Glyceryl stearate (SE) 0.50 Hydrogenated lecithin 0.30 Polysorbate 80 0.075 ·(Sodium acrylate / sodium acryloyldimethyltaurate) copolymer - 0.40 ·(Acrylates / Alkyl acrylate (C10-30)) Crosspolymer 0.15 Sodium carbomer 0.30 Sodium pyrosulfite 0.02 Citric acid 0.03 Potassium hydroxide 0.10 ·Fragrance 0.10 Ion-exchanged water residue

[0073] According to the above embodiment, the following effects can be obtained. (1) When the HLB value of component (C) is 7 or more and 14 or less, and the blending amount of component (C) is 0.5% by mass or more and 6.2% by mass or less, the oil-in-water emulsion cosmetic (i) reduces stickiness, (ii) enhances firmness or elasticity, and (iii) has excellent emulsion stability.

[0074] (2) When the blending amount of component (D) is 0.05 mass % or more and 5.0 mass % or less, it is possible to adjust effect (i) and effect (iii) within a range where there is a trade-off relationship.

[0075] (3) When the viscosity of component (F) is 15 mPa·s or more and 150 mPa·s or less, and the blending amount of component (F) is 0.2 mass% or more and 8.0 mass% or less, it is possible to adjust effect (i) and effect (iii) within a range where there is a trade-off relationship.

[0076] (4) When phenoxyethanol and ethanol are not contained and the amount of alkylglycerol blended is 0.05% by mass or more and 0.15% by mass or less, the effect (iv) is enhanced.

[0077] (5) If the following conditions are met, the effectiveness of achieving the effects (i) to (iii) will be enhanced. The blending amount of component (B) is 6.0% by mass or more and 20.0% by mass or less. The amount of component (C) is 1.7% by mass or more and 3.5% by mass or less. The amount of component (D) is 0.3% by mass or more and 1.5% by mass or less. The blending amount of component (E) is 1.2% by mass or more and 6.5% by mass or less. The blending amount of component (F) is 1.1% by mass or more and 3.0% by mass or less. The viscosity of component (F) is 15 mPa·s or more and 100 mPa·s or less.

[0078] The technical ideas derived from the above embodiment are as follows. [Appendix 1] An oil-in-water emulsion cosmetic containing component (A), component (B), component (C), component (D), component (E), component (F), and component (G), and not containing phenoxyethanol or ethanol, The component (A) is nicotinamide, The component (B) is a dihydric alcohol, The component (C) is a polyglycerol fatty acid ester, The component (D) is an N-long-chain acyl amino acid surfactant, The component (E) is a higher alcohol, The component (F) is dimethicone, The component (G) is an alkylglycerol, The component (C) has an HLB value of 7 or more and 14 or less, The viscosity of the component (F) is 15 mPa s or more and 100 mPa s or less, relative to the total amount of the oil-in-water emulsion cosmetic The blending amount of the component (A) is 1% by mass or more and 10% by mass or less, The blending amount of the component (B) is 6.0% by mass or more and 20.0% by mass or less, The blending amount of the component (C) is 1.7% by mass or more and 3.5% by mass or less, The blending amount of the component (D) is 0.3% by mass or more and 1.5% by mass or less, The blending amount of the component (E) is 1.2% by mass or more and 6.5% by mass or less, The blending amount of the component (F) is 1.1% by mass or more and 3.0% by mass or less, The blending amount of the component (G) is 0.05% by mass or more and 0.15% by mass or less. Oil-in-water emulsion cosmetics.

[0079] The oil-in-water emulsion cosmetic of Appendix 1 above (i) reduces stickiness, (ii) improves firmness or elasticity, and (iii) has excellent emulsion stability. Moreover, it is possible to adjust effect (i) and effect (iii) within a range where there is a trade-off relationship.

[0080] [Appendix 2] The component (C) is polyglyceryl-6 stearate, The component (D) is sodium N-stearoyl glutamate, The blending amount of the component (D) is 0.3% by mass or more and 0.8% by mass or less, The component (F) is 1.5% by mass or more and 2.5% by mass or less. An oil-in-water emulsion cosmetic according to Appendix 1.

[0081] The oil-in-water emulsion cosmetic of Appendix 2 above further enhances the effectiveness of achieving both effect (i) and effect (iii).

Claims

1. An oil-in-water emulsion cosmetic comprising component (A), component (B), and component (C), The component (A) is nicotinamide, The component (B) is a dihydric alcohol, The component (C) is a polyglycerol fatty acid ester, the blending amount of the component (A) is 1% by mass or more and 10% by mass or less based on the total amount of the oil-in-water emulsion cosmetic, the blending amount of the component (B) is 25% by mass or less based on the total amount of the oil-in-water emulsion cosmetic; The HLB value of the component (C) is 7 or more and 14 or less, the blending amount of the component (C) is 0.5% by mass or more and 6.2% by mass or less relative to the total amount of the oil-in-water emulsion cosmetic, Further containing component (D) and component (E), The component (D) is an N-long-chain acyl amino acid surfactant, The component (E) is a higher alcohol, the blending amount of the component (D) is 0.05% by mass or more and 5.0% by mass or less relative to the total amount of the oil-in-water emulsion cosmetic, The higher alcohol is a linear or branched, saturated or unsaturated alcohol having 12 or more carbon atoms. Oil-in-water emulsion cosmetics.

2. An oil-in-water emulsion cosmetic comprising component (A), component (B), and component (C), The component (A) is nicotinamide, The component (B) is a dihydric alcohol, The component (C) is a polyglycerol fatty acid ester, the blending amount of the component (A) is 3% by mass or more and 8% by mass or less based on the total amount of the oil-in-water emulsion cosmetic, the blending amount of the component (B) is 25% by mass or less based on the total amount of the oil-in-water emulsion cosmetic; The HLB value of the component (C) is 7 or more and 14 or less, the blending amount of the component (C) is 0.5% by mass or more and 6.2% by mass or less relative to the total amount of the oil-in-water emulsion cosmetic, Further containing component (D) and component (E), The component (D) is an N-long-chain acyl amino acid surfactant, The component (E) is a higher alcohol, the blending amount of the component (D) is 0.05% by mass or more and 5.0% by mass or less relative to the total amount of the oil-in-water emulsion cosmetic, the higher alcohol is a linear or branched, saturated or unsaturated alcohol having 12 or more carbon atoms, and the blending amount is 1.0% by mass or more and 6.5% by mass or less relative to the total amount of the oil-in-water emulsion cosmetic; Oil-in-water emulsion cosmetics.

3. Further containing component (F), The component (F) is dimethicone, the blending amount of the component (F) is 0.2% by mass or more and 8.0% by mass or less relative to the total amount of the oil-in-water emulsion cosmetic, The viscosity of the component (F) is 15 mPa·s or more and 150 mPa·s or less. The oil-in-water emulsion cosmetic according to claim 1 or 2.

4. Contains no phenoxyethanol or ethanol, Further containing component (G), The component (G) is an alkylglycerol, The blending amount of the component (G) is 0.05% by mass or more and 0.15% by mass or less. The oil-in-water emulsion cosmetic according to claim 3.

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