Oil-in-water type skin cleansing cosmetic

Abstract

To provide an oil-in-water type skin cleansing cosmetic excellent in detergency, giving no stickiness after cleansing, and giving a moist feeling after cleansing even when repeatedly used with hot water for a short period of time.SOLUTION: Provided is an oil-in-water type skin cleansing cosmetic comprising: 0.01 to 10 mass% of component (a), 10 to 50 mass% of component (b), 1 to 10 mass% of component (c), and 1 to 20 mass% of component (d). The component (a) is an alkyl oxirane derivative represented by formula (1). The component (b) is a polyhydric alcohol with 2 to 6 carbon atoms. The component (c) is a polyglycerol fatty acid ester type nonionic surfactant. The component (d) is a fat. The formula (1) is R1O-(AO)n-H (R1 is an alkyl group having 1 to 6 carbon atoms; AO is an oxyalkylene group having 3 carbon atoms; n is the average number of added moles of the oxyalkylene group AO; and 50≤n≤150).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an oil-in-water type skin cleansing cosmetic composition. [Background technology]

[0002] In recent years, with the growing awareness that excessive cleansing is bad for the skin, it is becoming increasingly recognized that it is important for skin cleansing cosmetics such as hand soaps that remove dirt from the skin to not only cleanse and sanitize the skin, but also to maintain moisture in the skin and prevent rough skin caused by dryness. Therefore, skin cleansing cosmetics have been improved not only in terms of cleansing ability, but also in terms of the skin condition after cleansing, such as the moist feeling of the skin after cleansing.

[0003] In Patent Document 1, a cream-type skin cleanser is provided that has good foaming, foam volume, foam quality (texture, elasticity), cleaning power, foam removal, and stability over time, and also has a moist feeling after rinsing, by combining a higher fatty acid salt, an N-acylalkyl taurine salt, and O-[2-hydroxy-3-(trimethylammonio)propyl]hydroxyethyl cellulose chloride. However, the lack of stickiness after washing is insufficient.

[0004] In Patent Document 2, a skin cleanser is provided that is compatible with water, has good foaming properties, and has good foam quality, is not sticky when rinsing, and leaves a moderate moist feeling and non-stickiness after washing, by combining a sucrose fatty acid ester composed of a linear saturated fatty acid having 12 to 18 carbon atoms, hydroxypropyl starch phosphate, a 2-methacryloyloxyethyl phosphorylcholine-stearyl methacrylate copolymer, a polyhydric alcohol, a fatty acid soap having 12 to 18 carbon atoms, an anionic surfactant, and an amphoteric surfactant. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2014-181223 A [Patent Document 2] JP 2016-132646 A Summary of the Invention [Problem to be solved by the invention]

[0006] In recent years, the importance of keeping the skin clean has been reaffirmed, and the number of times the skin is washed has increased. In particular, in the fields of childcare, nursing care, food, and the like, hygiene consciousness is high, so the number of times the skin is washed is particularly high. Furthermore, there are many stains that are difficult to remove with cold water, and the use of hot water is also increasing. Therefore, skin cleansing cosmetics are required not only to have cleansing properties and to have a moist and non-sticky feeling on the skin after washing, but also to have a moist feeling after washing even when repeatedly used with hot water for a short period of time. However, the above-mentioned compositions have room for improvement, such as insufficient cleansing properties and insufficient moist feeling after washing when repeatedly used with hot water for a short period of time.

[0007] To provide an oil-in-water type skin cleansing cosmetic which has excellent cleansing properties, is non-sticky after cleansing, and gives a moist feeling after cleansing even when repeatedly used in hot water for a short period of time. [Means for solving the problem]

[0008] The present invention provides the following. (1) An oil-in-water type skin cleansing cosmetic preparation, comprising the following components: 0.01 to 10 mass % of component (a), 10 to 50 mass % of component (b), 1 to 10 mass % of component (c), and 1 to 20 mass % of component (d): Component (a): an alkyloxirane derivative represented by formula (1) and satisfying the relationships of the following formulas (2), (3) and (4): (b) Component: Polyhydric alcohol having 2 to 6 carbon atoms (c) Ingredient: Polyglycerol fatty acid ester type nonionic surfactant (d) Ingredients: Contains at least one oil or fat that is solid at 25°C fats and oils R 1 O-(AO)n -H (1) (In formula (1), R 1 is a hydrocarbon group having 1 to 6 carbon atoms, AO is an oxyalkylene group having 3 carbon atoms; n is the average number of moles of oxyalkylene groups AO added, and 50≦n≦150. 0.35≦M L / M H ≦0.75 (2) (In formula (2), L is the length of the perpendicular line from the maximum point K, where the refractive index intensity on the chromatogram obtained by gel permeation chromatography is maximum, to the baseline B. Of the two points on the chromatogram where the refractive index intensity is L / 2, the point O is the one with the earlier elution time and the point Q is the one with the later elution time. P is the intersection point of the straight line G connecting points O and Q and the perpendicular line drawn from the maximum point K to the baseline. The distance between point O and intersection point P is M. H Let the distance between point Q and intersection point P be M L Let us assume that.) A s =W 1 / 2 / W 5% (3) 0.30≦A s ≦0.70 (4) (In formulas (3) and (4), of the two points on the chromatogram where the refractive index intensity is L / 20, the point with the earlier elution time is designated as point R, and the point with the later elution time is designated as point S. The intersection point between the straight line H connecting points R and S and the perpendicular line drawn from the maximum point K to the baseline B is designated as T, and the distance between point R and intersection point T is designated as W. 1 / 2 Let the distance between point R and point S be W 5% Let us assume that.) (2) An oil-in-water type skin cleansing cosmetic according to (1), characterized in that the component (d) further contains an oil that is liquid at 25°C, and the ratio of the mass of the oil that is liquid at 25°C to the mass of the oil that is solid at 25°C (mass of oil that is liquid at 25°C / mass of oil that is solid at 25°C) is 1 / 8 to 1 / 2. Effect of the Invention

[0009] According to the present invention, it is possible to provide an oil-in-water type skin cleansing cosmetic which has excellent cleansing properties, is non-sticky after cleaning, and leaves a moist feeling after cleaning even when repeatedly used in hot water for a short period of time. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a model chromatogram diagram for explaining ML and MH defined in the present invention. [Diagram 2] FIG. 2 is a model chromatogram diagram for explaining W1 / 2 and W5% defined in the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The oil-in-water type skin cleansing cosmetic composition of the present invention contains components (a) to (d). Hereinafter, the components will be described in order, starting with component (a). (Component (a)) The component (a) is an alkyloxirane derivative represented by formula (1) and satisfying the relationships of formulas (2), (3) and (4). R 1 O-(AO) n -H (1)

[0012] In formula (1), R 1 The hydrocarbon group having 1 to 6 carbon atoms represented by the formula (I) is a functional group consisting of carbon and hydrogen, and is one selected from an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, or an aralkyl group, and is preferably an alkyl group or an alkenyl group. R 1 The number of carbon atoms in R is 6 or less, and more preferably 4 or less. 1 R is preferably an alkyl or alkenyl group having 1 to 6 carbon atoms, and most preferably an alkyl group having 1 to 6 carbon atoms. 1 R may be a straight-chain hydrocarbon group or a branched-chain hydrocarbon group, but is preferably a straight-chain hydrocarbon group. Examples of the straight-chain alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, and a hexyl group.1 The hydrocarbon group having 1 to 6 carbon atoms represented by the formula (I) may be of one type or of two or more types.

[0013] In formula (1), AO is an oxyalkylene group having 3 carbon atoms, specifically an oxytrimethylene group or an oxymethylethylene group, with an oxymethylethylene group being preferred. In formula (1), n ​​is the average number of moles of oxyalkylene group AO added, and is 50 or more. If n is less than 50, the viscosity is low and the non-stickiness after washing may be lacking. However, as n increases, the stickiness after washing increases, so n is preferably 150 or less, and more preferably 120 or less.

[0014] Component (a) further satisfies the following formula (2): 0.35≦M L / M H ≦0.75 (2) (In formula (2), the length of the perpendicular line from the maximum point K on the chromatogram where the refractive index intensity is maximum to the baseline B is L, and of the two points on the chromatogram where the refractive index intensity is L / 2, the point O is the one with the earlier elution time and the point Q is the one with the later elution time. The intersection point between the line G connecting the points O and Q and the perpendicular line drawn from the maximum point K to the baseline is P. The distance between the point O and the intersection point P is M. H Let the distance between point Q and intersection point P be M L Let us assume that.)

[0015] That is, the alkyloxirane derivative used in the present invention is specified by a chromatogram obtained by gel permeation chromatography (GPC) using a differential refractometer. This chromatogram is a graph showing the relationship between refractive index intensity and elution time. Here, FIG. 1 is a model diagram of a chromatogram obtained by gel permeation chromatography of an alkyloxirane derivative, in which the horizontal axis indicates elution time and the vertical axis indicates refractive index intensity obtained by using a differential refractometer. When a sample solution is injected into a gel permeation chromatograph and developed, elution begins with the molecule with the highest molecular weight, and the elution curve rises as the refractive index intensity increases. Thereafter, after passing the maximum point K where the refractive index intensity is maximum, the elution curve starts to decline.

[0016] M L / M H are calculated from the chromatogram as follows: (1) Draw a perpendicular line from the maximum refractive index intensity point K on the chromatogram to the baseline B, and let the length of the perpendicular line be L. (2) Of the two points on the chromatogram where the refractive index strength is L / 2, the one with the earlier elution time is called point O, and the one with the later elution time is called point Q. (3) Let P be the intersection point between the straight line G connecting points O and Q and the perpendicular line drawn from the maximum point K of the refractive index intensity to the baseline B. (4) Let the distance between point O and intersection point P be M. H , the distance between the intersection point P and point Q is M L Let us assume that.

[0017] In addition, in the gel permeation chromatography of the alkyloxirane derivative of the present invention, when there are multiple maximum points of refractive index intensity in the chromatogram, the point with the highest refractive index intensity among them is taken as the maximum point K. Furthermore, when there are multiple maximum points of the same refractive index intensity, the one with the later elution time is taken as the maximum refractive index intensity K. In this case, peaks due to the developing solvent used in the gel permeation chromatography and false peaks due to baseline fluctuations due to the column or device used are excluded.

[0018] Here, component (a) is M L / M H is 0.35≦M L / M H ≦0.75. L / M H If M is greater than 0.75, the viscosity of the alkyloxirane derivative decreases, and when this is incorporated into an oil-in-water type skin cleansing cosmetic, the moist feeling after repeated washing with hot water is lost. L / M H is set to 0.75 or less, preferably 0.65 or less, and more preferably 0.55 or less. L / M H The smaller the M, the greater the bias toward the high molecular weight side in the molecular weight distribution, and the higher the viscosity of the alkyloxirane derivative. L / M H If M is less than 0.35, the viscosity becomes too high, which causes the skin to feel less sticky after washing. L / M H is set to 0.35 or more, and from the viewpoint of moist feeling after repeated washing with hot water, it is more preferably set to 0.40 or more, and particularly preferably set to 0.45 or more.

[0019] In addition, the alkyloxirane derivative used in the present invention has a chromatogram, which is represented by the refractive index intensity and elution time obtained by gel permeation chromatography using a differential refractometer, that is asymmetric on the left and right, and the asymmetry value As of the peak of the chromatogram, which is calculated as shown below, satisfies formulas (3) and (4). As=W 1 / 2 / W 5% (3) 0.30≦A≦0.70 (4)

[0020] The calculation method of As will be further explained with reference to the model diagram of the chromatogram in Figure 2. The horizontal axis indicates the elution time, and the vertical axis indicates the refractive index intensity obtained using a differential refractometer. (1) Draw a perpendicular line from the maximum refractive index intensity point K on the chromatogram to the baseline B, and let its length be L. (2) Of the two points on the chromatogram where the refractive index intensity is L / 20, the one with the earlier elution time is designated as point R, and the one with the later elution time is designated as point S. (3) Let T be the point of intersection between the straight line H connecting points R and S and the perpendicular line drawn from the maximum point K of the refractive index intensity to the baseline B. (4) Let the distance between point R and intersection point T be W 1 / 2 , the distance between point R and point S is W 5% Let us assume that.

[0021] In the present invention, As satisfies 0.30≦As≦0.70. By making As 0.70 or less, the viscosity is appropriately improved, and a moist feeling can be imparted after repeated washing with hot water. From this viewpoint, it is more preferable that As is 0.65 or less. In addition, the smaller As is, the greater the bias toward the high molecular weight side in the molecular weight distribution, and the viscosity increases due to this. Therefore, from the viewpoint of imparting non-stickiness after washing, As is made 0.30 or more, and more preferably 0.57 or more.

[0022] In the present invention, M L , M H Gel permeation chromatography (GPC) to determine As was performed using a SHODEX (registered trademark) GPC101 dedicated GPC system equipped with a SHODEX RI-71s differential refractometer, a SHODEX KF-G guard column, and three SHODEX KF804L columns in series, with the column temperature at 40°C and tetrahydrofuran as the developing solvent flowing at a flow rate of 1 ml / min, and 0.1 ml of a 0.1 wt % tetrahydrofuran solution of the obtained reaction product being injected, and a chromatogram expressed by refractive index intensity and elution time was obtained using a BORWIN GPC calculation program.

[0023] Specific examples of the alkyloxirane derivative include polypropylene glycol methyl ether, polypropylene glycol ethyl ether, polypropylene glycol propyl ether, polypropylene glycol butyl ether, polypropylene glycol pentyl ether, and polypropylene glycol hexyl ether, and preferably polypropylene glycol propyl ether and polypropylene glycol butyl ether.

[0024] Hereinafter, the total mass of the oil-in-water type skin cleansing cosmetic composition is taken as 100 mass %. If the content of component (a) is high, not only will stickiness occur after washing but washing properties may also decrease, so the content of component (a) is set to 10% by mass or less, preferably 7% by mass or less, more preferably 3% by mass or less, and particularly preferably 2% by mass or less. Also, if the content of component (a) is low, not only will non-stickiness after washing be impaired but the moist feeling after washing when repeatedly used in hot water in a short period of time may also be reduced, so the content of component (a) is set to 0.01% by mass or more, preferably 0.1% by mass or more, and more preferably 0.5% by mass or more.

[0025] ((b) component) The (b) component is a polyhydric alcohol having 2 to 6 carbon atoms. Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, methylpropylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, 1,2-pentylene glycol, 1,2-hexylene glycol, 1,6-hexanediol, glycerin, trimethylolpropane, diglycerin, glucose, maltose, and sorbitol. These (b) components may be used alone or in combination of two or more. Among them, glycerin, dipropylene glycol, and pentylene glycol are preferred, and glycerin and dipropylene glycol are more preferred.

[0026] When the total mass of the oil-in-water type skin cleansing cosmetic is taken as 100% by mass, a high content of component (b) may cause stickiness after cleansing, so the content of component (b) is set to 50% by mass or less, preferably 40% by mass or less, and more preferably 30% by mass or less. Also, if the content of component (b) is low, it may be difficult to feel a moist feeling after cleansing when repeatedly used with hot water in a short period of time, so the content is set to 10% by mass or more, preferably 15% by mass or more, and more preferably 25% by mass or more.

[0027] ((c) component) Component (c) is a polyglycerol fatty acid ester type nonionic surfactant.

[0028] The polyglycerol fatty acid ester type nonionic surfactant is an ester of polyglycerol having an average degree of polymerization of 2 to 10 and a fatty acid having 10 to 22 carbon atoms. The average degree of polymerization of this polyglycerol is preferably 2 to 8, more preferably 2 to 6, further preferably 2 or 3, and particularly preferably 2.

[0029] The fatty acid is preferably a fatty acid having 12 to 20 carbon atoms, more preferably a fatty acid having 16 to 18 carbon atoms. These fatty acids may be saturated, unsaturated, straight-chain, or branched, or may be a mixture of these fatty acids. Examples of fatty acids include caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, isostearic acid, oleic acid, and coconut oil fatty acid. Among these, preferred are lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, and oleic acid, more preferred are palmitic acid, stearic acid, and isostearic acid, and even more preferred are palmitic acid and isostearic acid, with isostearic acid being particularly preferred.

[0030] The component (c) preferably has an HLB value of 2 to 10. The HLB value is calculated according to the following formula. HLB=20(1-S / A) S: Saponification value of ester, A: Acid value of fatty acid

[0031] When the total mass of the oil-in-water type skin cleansing cosmetic is taken as 100% by mass, a small amount of component (c) not only reduces the cleansing ability but also makes it difficult to feel the lack of stickiness after rinsing, so the content of component (c) is set to 1% by mass or more, preferably 2% by mass or more, and more preferably 3% by mass or more. Also, a large amount of component (c) may make it difficult to feel a moist feeling after washing when repeatedly used in hot water for a short period of time, so the content of component (c) is set to 10% by mass or less, preferably 8% by mass or less, and more preferably 7% by mass or less.

[0032] ((d) Component: Oil and fat) The component (d) used in the present invention is an oil or fat. It contains at least fats and oils that are solid at 25°C. Specific examples of fats and oils include camellia oil, olive oil, avocado oil, meadowfoam oil, macadamia nut oil, coconut oil, sunflower oil, sesame oil, grapeseed oil, rice oil, rapeseed oil, glyceryl triisostearate, glyceryl triisopalmitate, glyceryl tri-2-ethylhexanoate, tri(capryl-capric acid)glyceryl, triethylhexanoin, etc. Examples of fats and oils that are solid at 25°C include coconut butter, shea butter, cacao butter, hydrogenated palm oil, hydrogenated rapeseed oil, etc.

[0033] As fats and oils that are liquid at 25°C, olive oil, sunflower oil, sesame oil, grapeseed oil, and rapeseed oil are preferred, and as fats and oils that are solid at 25°C, shea butter and cacao butter are preferred. Particularly preferably, as component (d), fats and oils that are liquid at 25°C and fats and oils that are solid at 25°C can be used in combination. In this case, the mass ratio (fat and oil that is liquid at 25°C) / (fat and oil that is solid at 25°C) is preferably 1 / 10 to 10 / 1, more preferably 1 / 8 to 1 / 2, and even more preferably 1 / 6 to 1 / 3. As a combination of fats and oils that are liquid at 25°C and fats and oils that are solid at 25°C, for example, it is particularly preferred to use sunflower oil and shea butter in combination.

[0034] If the amount of component (d) is small, it may be difficult to feel a moist feeling after washing when repeatedly used in hot water for a short period of time, so the content of component (d) is set to 1% by mass or more, preferably 3% by mass or more, and more preferably 5% by mass or more. Also, if the amount of component (d) is large, not only the stickiness after washing is impaired but also the cleaning ability may decrease, so the content of component (d) is set to 20% by mass or less, preferably 15% by mass or less, and more preferably 10% by mass or less.

[0035] The oil-in-water type skin cleansing cosmetic may contain additives other than the components (a) to (d). As such additives, those used in cosmetic applications may be used, such as moisturizers, thickeners, preservatives, pH adjusters, and fragrances. When the total mass of the oil-in-water type skin cleansing cosmetic is taken as 100% by mass, the total amount of additives is preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 2% by mass or less. The remainder of the oil-in-water type skin cleansing cosmetic other than the components (a) to (d) and any additive components is water. The water content is preferably 20 to 90 mass%, more preferably 30 to 85 mass%, and even more preferably 40 to 80 mass%. EXAMPLES

[0036] The present invention will be described in more detail below with reference to Examples and Comparative Examples. Compounds a-1 to a-3 used in the Examples and Comparative Examples were synthesized as follows.

[0037] (Reference synthesis example: synthesis of composite metal cyanide complex catalyst) Into 2.0 ml of an aqueous solution containing 2.1 g of zinc chloride, 15 ml of an aqueous solution containing 0.84 g of potassium hexacyanocobaltate K3Co(CN)6 was added dropwise over 15 minutes while stirring at 40°C. After the addition was completed, 16 ml of water and 16 g of tert-butyl alcohol were added, the temperature was raised to 70°C, and the mixture was stirred for 1 hour. After cooling to room temperature, a filtration operation (first filtration) was performed to obtain a solid. To this solid, 14 ml of water and 8.0 g of tert-butyl alcohol were added, and the mixture was stirred for 30 minutes, followed by a filtration operation (second filtration) to obtain a solid. Furthermore, 18.6 g of tert-butyl alcohol and 1.2 g of methanol were added to this solid again, and after stirring for 30 minutes, a filtration operation (third filtration) was performed. The obtained solid was dried at 40°C under reduced pressure for 3 hours to obtain 0.7 g of a composite metal cyanide complex catalyst.

[0038] (Compounds a-1~a-3) 200g of butylpropylene glycol and 0.2g of the composite metal cyanide complex catalyst of the reference synthesis example were charged into a stainless steel 5 liter (capacity 4,890ml) pressure-resistant reactor equipped with a thermometer, pressure gauge, safety valve, nitrogen gas inlet tube, stirrer, vacuum exhaust tube, cooling coil, and steam jacket. After nitrogen replacement, the temperature was raised to 110°C, and 210g of methyloxirane was charged from the nitrogen gas inlet tube over 4 hours under conditions of 0.3MPa or less. At this time, the changes in pressure and temperature in the reactor were measured over time. After 4 hours, the pressure in the reactor suddenly decreased. After that, while maintaining the temperature in the reactor at 110°C, methyloxirane was gradually charged from the nitrogen gas inlet tube under conditions of 0.6MPa or less, and 3,287g of methyloxirane was continuously added under pressure with stirring. At this time, it took 60 minutes to add 840 g of methyloxirane, 108 minutes to add 2,100 g, and 132 minutes to add 3,287 g. After the addition was completed, the mixture was reacted at 110°C for 1 hour, and then 1,680 g was extracted from the reaction tank. The temperature of the residue in the reaction vessel was then raised to 110°C, and 174 g of methyloxirane was added over 20 minutes from the nitrogen gas inlet tube under conditions of 0.6 MPa or less while maintaining the temperature inside the reaction vessel at 110°C. After completion of the addition, the reaction was carried out at 110°C for 1 hour, and then 619 g was again extracted from the reaction vessel, and while blowing in nitrogen gas, the reaction vessel was subjected to reduced pressure treatment at 75-85°C and 50-100 Torr for 1 hour, followed by filtration.

[0039] The resulting reaction product (compound a-1) was subjected to M measurement using a Showa Denko GPC (gel permeation chromatography) measurement device as described above. L , M H As a result, M L / M H was 0.52 and As was 0.61.

[0040] The temperature of the residue in the reaction vessel was further increased to 110°C, and 121 g of methyloxirane was added over 30 minutes from the nitrogen gas inlet tube under conditions of 0.6 MPa or less while maintaining the temperature inside the reaction vessel at 110°C. After completion of the addition, the reaction was carried out at 110°C for 1 hour, and then 370 g was again extracted from the reaction vessel, and the reaction vessel was subjected to reduced pressure treatment at 75-85°C and 50-100 Torr for 1 hour while blowing in nitrogen gas, and then filtered. The obtained reaction product (compound a-2) was measured by gel permeation chromatography. The resulting reaction product (M of compound a-2) L / M H was 0.42 and As was 0.59.

[0041] The temperature of the residue in the reaction vessel was further increased to 110°C, and while maintaining the temperature in the reaction vessel at 110°C, 122 g of methyloxirane was added over 30 minutes from the nitrogen gas inlet tube under conditions of 0.6 MPa or less. After reacting at 110°C for 1 hour, the mixture was subjected to reduced pressure treatment at 75-85°C and 50-100 Torr for 1 hour while blowing in nitrogen gas, and then filtered. The resulting reaction product (compound a-3) was measured by gel permeation chromatography. The resulting reaction product (M of compound a-3) L / M H was 0.36 and As was 0.57.

[0042] In addition, for compound a' (PREMINOL S1004F), the chromatogram does not have one refractive index maximum point, and is not a single-peak peak, so the M L / M H and As values ​​are shown. In Table 1, the hydroxyl value was measured in accordance with JIS K-1557-1, the kinematic viscosity was measured in accordance with JIS K-2283, and the degree of unsaturation was measured in accordance with JIS K-1557, and the molecular weight was calculated from the hydroxyl value.

[0043] [Examples 1 to 14, Comparative Examples 1 to 6] Oil-in-water type skin cleansing cosmetics were prepared by the following method with the blending ratios shown in Tables 2 to 4. The common additive components in Tables 2 to 4 are the 10 components shown in Table 5. That is, an aqueous phase containing component (b) and ion-exchanged water was mixed with an oily component consisting of components (a), (c), (d) and common additive components 1, 2 and 3, heated to 75-80°C and mixed using a homomixer, after which common additive components 4 and 5 were added and cooled, and common additive components 6, 7, 8, 9 and 10 were added to obtain an oil-in-water type skin cleansing cosmetic. The oil-in-water type skin cleansing cosmetic thus obtained was evaluated for four items according to the following evaluation criteria. The evaluation results are shown in Tables 2 to 4.

[0044] [Evaluation items and evaluation criteria] The following items were evaluated, and a four-level rating from "◎" to "×" was given based on the total score. (1) Cleanability Twenty men and women (aged 24 to 54) were used as panelists. 5g of rapeseed oil was applied to the hands as an oily stain, and 2g of an oil-in-water type skin cleansing cosmetic was rubbed into the hands five times. After rinsing with running water without scrubbing, the degree to which the stain was removed was judged as follows, and the total score of the 20 panelists was calculated and the judgment was made. 2 points: If you feel that the dirt has been removed. 1 point: If you feel that the stain is difficult to remove. 0 points: If you feel that the dirt has not been removed. Products with a total score of 30 or more were judged to be oil-in-water type skin cleansers with excellent cleansing properties.

[0045] (2) No stickiness after washing Twenty men and women (aged 24 to 54) were used as panelists. They applied 2 g of the oil-in-water type skin cleansing cosmetic to their hands five times, rinsed them under running water without rubbing, and towel-dried them. After five minutes, they judged the lack of stickiness as described below, and the total score of the 20 panelists was calculated and the judgment was made. 2 points: If it does not feel sticky. 1 point: If it feels slightly sticky. 0 points: If the product feels sticky. A total score of 30 or more was judged to be an oil-in-water type skin cleanser with excellent non-stickiness. (3) Moisturizing feeling after repeated washing with hot water Twenty men and women (aged 24 to 54) were used as panelists. They rubbed 2 g of the oil-in-water type skin cleansing cosmetic into their hands five times, then rinsed with hot water (approximately 38°C) and towel-dried. This process was repeated 10 times over a period of approximately five minutes, and the moist feeling five minutes after towel-drying was judged as follows. The total score of the 20 panelists was calculated and the judgment was made. 2 points: If you feel it is moist. 1 point: If you feel it is slightly moist. 0 points: If you feel there is no moisturizing sensation. Products with a total score of 30 or more were judged to be oil-in-water type skin cleansers that provided excellent moisturizing feeling after repeated washing with hot water.

[0046] <4-level evaluation based on total score> ◎: Total score is 35 or more ○: Total score is between 30 and 35 △: Total score is between 20 and 30 ×: Total points are less than 20

[0047] [Table 1]

[0048] [Table 2]

[0049] [Table 3]

[0050] [Table 4]

[0051] [Table 5]

[0052] From Examples 1 to 14, it was found that all of the oil-in-water type skin cleansing cosmetics using the components of the present invention were excellent in terms of cleansing properties, non-stickiness after cleansing, and moist feeling after repeated washing with hot water.

[0053] On the other hand, in Comparative Examples 1 to 6, sufficient performance was not obtained. In Comparative Example 1, since the component (a) was not contained, the lack of stickiness after washing and the moist feeling after repeated washing with hot water were insufficient. Comparative Example 2 did not contain component (a) and contained an alkyloxirane derivative with a narrow molecular weight distribution as component (a'), and the lack of stickiness after washing and the moist feeling after repeated washing with hot water were insufficient. In Comparative Example 3, since component (b) was not contained, the moist feeling after repeated washing with hot water was insufficient. In Comparative Example 4, since the component (c) was not contained, the cleaning properties and non-stickiness after cleaning were insufficient. Comparative Example 5 did not contain component (d) and contained polyoxyethylene alkyl ether as component (d'), and the cleaning properties, lack of stickiness after washing, and moist feeling after repeated washing with hot water were insufficient. In Comparative Example 6, since the component (d) was not contained, the moist feeling after washing and the moist feeling after repeated washing with hot water were insufficient.

Claims

1. The oil-in-water type skin cleansing cosmetic preparation comprises the following components: 0.01 to 10 mass % of component (a), 10 to 50 mass % of component (b), 1 to 10 mass % of component (c), and 1 to 20 mass % of component (d): Component (a): An alkyloxirane derivative represented by formula (1) and satisfying the relationships of the following formulas (2), (3) and (4): Component (b): Polyhydric alcohol having 2 to 6 carbon atoms Component (c): Polyglycerol fatty acid ester type nonionic surfactant Component (d): An oil or fat containing at least an oil or fat that is solid at 25°C. R １ O-(AO) ｎ -H ・・・・(1) (In formula (1), R １ is a hydrocarbon group having 1 to 6 carbon atoms, AO is an oxyalkylene group having 3 carbon atoms; n is the average number of moles of oxyalkylene group AO added, and 50≦n≦150. 0.35≦M Ｌ / M Ｈ ≦0.75 ・・・・(2) (In formula (2), the length of the perpendicular line from the maximum point K at which the refractive index intensity on the chromatogram obtained by gel permeation chromatography is maximum to the baseline B is defined as L, and of two points on the chromatogram at which the refractive index intensity is L / 2, the point O is the one with the earlier elution time and the point Q is the one with the later elution time. The intersection point between the straight line G connecting the points O and Q and the perpendicular line drawn from the maximum point K to the baseline is defined as P. The distance between the point O and the intersection point P is defined as M. Ｈ Let the distance between point Q and intersection point P be M Ｌ (Assuming that.) A ｓ =W １／２ / W ５％ ・・・(3) 0.30≦A ｓ ≦0.70 ・・・(4) (In formulas (3) and (4), of the two points on the chromatogram where the refractive index intensity is L / 20, the point with the earlier elution time is designated as point R, and the point with the later elution time is designated as point S. The intersection point between the straight line H connecting points R and S and the perpendicular line drawn from the maximum point K to the baseline B is designated as T, and the distance between point R and intersection point T is designated as W. １／２ Let the distance between point R and point S be W ５％ (Assuming that.)

2. An oil-in-water type skin cleansing cosmetic composition as described in claim 1, characterized in that the component (d) further contains an oil that is liquid at 25°C, and the ratio of the mass of the oil that is liquid at 25°C to the mass of the oil that is solid at 25°C (mass of oil that is liquid at 25°C / mass of oil that is solid at 25°C) is 1 / 8 to 1 / 2.

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