JP2018104342A - Oil-in-water type emulsion skin cosmetic - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil-in-water type emulsion skin cosmetic which spreads well while giving a thick feeling during application, has good skin compatibility and has excellent sustainability of moist feeling without sticky feeling.SOLUTION: There is provided an oil-in-water type emulsion skin cosmetic which comprises 0.1 to 10 mass% of the following high molecular weight alkyloxirane derivative (a), 1 to 15 mass% of a polyhydric alcohol having 2 to 6 carbon atoms (b), 1 to 25 mass% of a liquid oil (c) and 1 to 10 mass% of a nonionic surfactant (d). An alkyloxirane derivative (a) which is represented by the formula (1) and satisfies the relations of the following expressions (2), (3) and (4): RO-(AO)n-H (1) (Rrepresents a hydrocarbon group having 1 to 22 carbon atoms, AO represents an oxyalkylene group having 3 carbon atoms and n represents a number of 25 or more.): 0.35≤M/M≤0.75 (2): As=W/W(3): 0.30≤As≤0.70 (4)SELECTED DRAWING: Figure 1

Description

  The present invention relates to an oil-in-water emulsified skin cosmetic that has good elongation while having a thickness while being applied, has good skin familiarity, does not feel sticky, and has excellent durability of moisture retention.

  The human skin surface is covered with a sebum membrane, and the transpiration of water from the body is moderately suppressed. Maintaining appropriate skin moisture is important from the viewpoint of skin health. If the moisture is insufficient, rough skin or the like is likely to occur. If you wash your face or take a bath, the sebum film will be temporarily removed, and it will be easy to lose moisture from your skin. Use moisturizing cosmetics such as skin lotion, serum, milky lotion, cream, etc. to supplement the moisture. There is a need. Among these, emulsions and creams have a higher moisturizing effect because the moisture is supplemented with a moisturizing agent such as a polyhydric alcohol and the oil further forms a film on the skin to suppress moisture evaporation of the skin.

  In general, these moisturizing cosmetics are important for continuous use, so it is important to have a good feeling of use in order to encourage consumers to use them continuously. is there. The feeling of use preferred by consumers includes good stretch and skin familiarity, and no stickiness. By blending polar oils such as ester oils and vegetable oils, an emulsified composition (Patent Document 1) excellent in feeling of use, such as good elongation and skin familiarity and no stickiness, is disclosed. In this way, improvements in the feeling of use of moisturizing cosmetics are being promoted more and more.

  On the other hand, consumer values are becoming increasingly diverse, and in addition to the conventional feeling of use such as the touch, a thick feel has recently been demanded when applying to give a high-class feel.

  Therefore, an oil-in-water emulsion composition combining a polyglycerin fatty acid ester and a higher alcohol (Patent Document 2) or an oil-in-water emulsion composition combining a high melting point oil and glycerin (Patent Document) 3) has been attempted.

JP 2013-139395 A JP 2015-189762 JP-A-2015-147734

  However, if a thickness is given at the time of application, the feeling of use such as good stretch and familiarity with the skin may not be sufficient, and there is a problem of how to balance the thickness at the time of application and an excellent feeling of use.

  Furthermore, although the conventional moisturizing cosmetics provided a sufficient moisturizing feeling immediately after application or after several hours, it was difficult to maintain the moisturizing feeling for a long time of about half a day when drying in winter. In addition, there has been a demand for a moisturizing cosmetic material that sufficiently satisfies all of the thickness at the time of application, the excellent feeling of use, and the durability of the moisturizing feeling.

  An object of the present invention is to provide an oil-in-water emulsified skin cosmetic that has good thickness, feels good on skin, does not feel sticky, and has a long-lasting moisturizing feeling.

  The inventors of the present invention have made researches to solve the above-mentioned problems. As a result, the above object can be achieved by combining a specific alkyloxirane derivative, a polyhydric alcohol having 2 to 6 carbon atoms, a liquid oil, and a nonionic surfactant. I found that I can achieve.

That is, the present invention is defined as follows: (a) 0.1 to 10% by mass of a high molecular weight alkyloxirane derivative, (b) 1 to 15% by mass of a polyhydric alcohol having 2 to 6 carbon atoms, (c 1) to 25% by mass of a liquid oil and (d) 1 to 10% by mass of a nonionic surfactant. The present invention relates to an oil-in-water emulsified skin cosmetic.

(A) An alkyloxirane derivative represented by the following formula (1) and satisfying the relationship of the following formula (2), formula (3) and formula (4)

R ¹ O— (AO) n—H (1)

(In the formula (1),
R ¹ represents a hydrocarbon group having 1 to 22 carbon atoms,
AO represents an oxyalkylene group having 3 carbon atoms,
n represents a number of 25 or more. )

_{0.35 ≦ M L / M H ≦} 0.75 ···· (2)

(In Formula (2), the length of the perpendicular from the maximum point K to the base line B where the refractive index intensity on the chromatogram obtained by gel permeation chromatography measurement is maximum is L, and the refractive index intensity is L / 2. Of the two points on the chromatogram, the point with the earlier elution time is point O, the point with the later elution time is point Q, and the line G connecting point O and point Q and the maximum point K are drawn to the baseline. when the intersection of the perpendicular is P was the distance between the point O and the intersection P and M _H, the distance between the point Q and the point of intersection P and M _L.)

As = W _1/2 / W _5% (3)
0.30 ≦ As ≦ 0.70 (4)

(In the formula (3), the point where the elution time is early among the two points where the refractive index intensity is L / 20 on the chromatogram is point R, the point where the elution time is late is point S, and point R and point S Let T be the intersection of the straight line H connecting the line H and the perpendicular drawn from the local maximum K to the base line B, the distance between the point R and the intersection T is W _1/2 , and the distance between the point R and the point S is W _5% And)

  The oil-in-water type emulsified skin cosmetic of the present invention has good elongation while it is felt in thickness, has good skin fit, does not feel sticky, and is excellent in sustainability of moisturizing feeling.

FIG. 1 is a model chromatogram for explaining _ML and _MH defined in the present invention. FIG. 2 is a model chromatogram for explaining W _1/2 and W _5% defined in the present invention.

Hereinafter, embodiments of the present invention will be described.
The oil-in-water emulsified skin cosmetic of the present invention contains the following components (a), (b), (c), and (d). Hereinafter, the component (a), the component (b), the component (c), and the component (d) will be described sequentially.

[(A) component]
The component (a) used in the present invention is an alkyloxirane derivative represented by the following formula (1) and satisfying the relations of the following formulas (2), (3) and (4).
R ¹ O— (AO) n—H (1)
(In the formula (1),
R ¹ represents a hydrocarbon group having 1 to 22 carbon atoms,
AO represents an oxyalkylene group having 3 carbon atoms,
n represents a number of 25 or more. )

_{0.35 ≦ M L / M H ≦} 0.75 ···· (2)
As = W _1/2 / W _5% (3)
0.30 ≦ As ≦ 0.70 (4)

In the formula (1), R ¹ is a hydrocarbon group having 1 to 22 carbon atoms, and AO is an oxyalkylene group having 3 carbon atoms. n is an average addition mole number of the oxyalkylene group AO and is 25 or more.

In the formula (1), the hydrocarbon group having 1 to 22 carbon atoms represented by R ¹ is a functional group composed of carbon and hydrogen, and is selected from an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, or an aralkyl group. And preferably an alkyl group or an alkenyl group. The carbon number of R ¹ is preferably 14 or less, and more preferably 6 or less. R ¹ is more preferably an alkyl group or alkenyl group having 1 to 14 carbon atoms, more preferably an alkyl group or alkenyl group having 1 to 6 carbon atoms, and most preferably an alkyl group having 1 to 6 carbon atoms.

R ¹ may be a straight chain hydrocarbon group or a branched chain hydrocarbon group, but is preferably a straight chain hydrocarbon group. In particular, examples of the linear 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. The hydrocarbon group having 1 to 22 carbon atoms represented by R ¹ may be only one type or two or more types.

  AO is an oxyalkylene group having 3 carbon atoms, specifically a trimethylene group or a methylethylene group, but a methylethylene group is preferred.

N is an average added mole number of the oxyalkylene group AO and is 25 or more. When n is less than 25, the viscosity is low, and there is a possibility that the thickness at the time of application and the sustainability of the moisturizing feeling are insufficient. From this viewpoint, n is set to 25 or more, and more preferably 50 or more.
Also, as n increases, the viscosity of the composition increases and handling properties deteriorate, so that n is preferably 150 or less and more preferably 120 or less from the viewpoint of handling.

  The alkyloxirane derivative of component (a) used in the present invention is defined by a chromatogram obtained by using a differential refractometer in gel permeation chromatography (GPC). 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. The horizontal axis represents the elution time, and the vertical axis represents the refractive index strength obtained using a differential refractometer. Show.

  When a sample solution is injected into a gel permeation chromatograph and developed, elution starts from the molecule with the highest molecular weight, and the elution curve increases as the refractive index intensity increases. Thereafter, when the maximum point K at which the refractive index intensity is maximum is passed, the elution curve is lowered.

  Further, in the gel permeation chromatography of the alkyloxirane derivative of the present invention, when there are a plurality of refractive index intensity maximum points in the chromatogram, the point having the highest refractive index intensity is set as the maximum point K. Further, when there are a plurality of local maximum points having the same refractive index intensity, the longer elution time is set as the local maximum point K of the refractive index intensity. At this time, the peak due to the developing solvent used in the gel permeation chromatography and the pseudo peak due to the fluctuation of the baseline due to the column or apparatus used are excluded.

M _L / M _H is calculated from the chromatogram as follows.
(1) A perpendicular line is drawn from the maximum point K of the refractive index intensity on the chromatogram to the base line B, and the length of the perpendicular line is L.
(2) Of the two points on the chromatogram having a refractive index intensity of L / 2, the point with the earlier elution time is designated as point O, and the point with the later elution time is designated as point Q.
(3) Let P be the intersection of a straight line G connecting point O and point Q and a perpendicular drawn from the local maximum point K of the refractive index intensity to the base line B.
(4) point O and the intersection point P distance _{M H} of the distance of an intersection P and the point Q and _{M L.}

In the alkyloxirane derivative of the present invention, M _L / M _H satisfies 0.35 ≦ M _L / M _H ≦ 0.75. When M _L / _MH is larger than 0.75, the viscosity of the alkyloxirane derivative is lowered. From this viewpoint, M _L / _{MH is set} to 0.75 or less, and more preferably set to 0.62 or less.

Further, as M _L / M _H becomes smaller, the bias on the high molecular weight side in the molecular weight distribution becomes larger, and an increase in viscosity derived therefrom is observed. When M _L / _{M H} is less than 0.35, the handling property deteriorates excessively high viscosity. From this point of view, M _L / _MH is 0.35 or more, and more preferably 0.36 or more.

  Further, the alkyloxirane derivative of component (a) has a left-right asymmetric chromatogram represented by the refractive index intensity and elution time obtained using a differential refractometer in gel permeation chromatography, as shown below. The asymmetry value As of the peak of the chromatogram obtained by satisfying the above formulas (3) and (4).

  The method for calculating As will be further described with reference to the model diagram of the chromatogram in FIG. The horizontal axis represents the elution time, and the vertical axis represents the refractive index intensity obtained using a differential refractometer.

  When a sample solution is injected into a gel permeation chromatograph and developed, elution starts from the molecule with the highest molecular weight, and the elution curve increases as the refractive index intensity increases. After that, the maximum point where the refractive index intensity is maximum is passed, and the elution curve is lowered.

(1) A perpendicular line is drawn from the maximum point K of the refractive index intensity on the chromatogram to the base line B, and its length is set to L.
(2) Of the two points on the chromatogram where the refractive index intensity is L / 20, point with the earlier elution time as point R and point with the later elution time as point S.
(3) Let T be the intersection of a straight line H connecting point R and point S and a perpendicular drawn from the maximum point K of the refractive index intensity to the base line B.
(4) The distance between the point R and the intersection T is W _1/2 , and the distance between the point R and the point S is W _5% .

  In the present invention, As satisfies 0.30 ≦ As ≦ 0.70. By setting As to 0.70 or less, the viscosity is improved. From this viewpoint, it is more preferable that As is 0.65 or less.

  Moreover, as As becomes smaller, the deviation of both sides of the polymer in the molecular weight distribution becomes larger, and an increase in viscosity derived therefrom is observed. Therefore, As is set to 0.30 or more from the viewpoint of handling, but more preferably 0.57 or more.

In the present invention, gel permeation chromatography (GPC) for determining M _L , _MH and As is a system dedicated to SHODEX (registered trademark) GPC101GPC as a system, SHODEX RI-71s as a differential refractometer, and SHODEX KF as a guard column. -G, three columns of SHODEX KF804L were installed continuously, column temperature was 40 ° C., tetrahydrofuran was flowed as a developing solvent at a flow rate of 1 ml / min, and 0.1 ml of 0.1 wt% tetrahydrofuran solution of the obtained reaction product was injected. Then, using the BORWIN GPC calculation program, a chromatogram represented by the refractive index intensity and the elution time is obtained.

  The content of the component (a) in the oil-in-water emulsified skin cosmetic of the present invention is 0.1 to 10% by mass. When the content of the component (a) is less than 0.1% by mass, the thickness at the time of coating is impaired, and the effect of maintaining the moisturizing feeling is lowered. The above is preferable, and 3% by mass or more is more preferable.

  Further, if the content of the component (a) exceeds 10% by mass, it becomes sticky and the elongation becomes worse, so it is 10% by mass or less, preferably 8% by mass or less, more preferably 6% by mass or less. .

[Component (b)]
The component (b) is a polyhydric alcohol having 2 to 6 carbon atoms and a compound having two or more hydroxyl groups in the molecule. It is preferable that the component (b) has 4 or less hydroxyl groups in the molecule.
Specific examples of the component (b) include propylene glycol, propanediol, glycerin, 1,3-butylene glycol, diethylene glycol, 1,2-pentanediol, isoprene glycol, hexylene glycol, diglycerin, and dipropylene glycol. 1 type, or 2 or more types selected from these can be used. Among these, propylene glycol, glycerin, 1,3-butylene glycol, 1,2-pentanediol, hexylene glycol, and dipropylene glycol are preferable from the viewpoint of antiseptic properties, feeling of use, and the like, and glycerin and dipropylene glycol are particularly preferable. Propylene glycol.

  The content of the component (b) in the oil-in-water emulsified skin cosmetic of the present invention is 1 to 15% by mass. When the content of the component (b) is less than 1% by mass, the moisturizing effect is weak and the sustainability of the moisturizing feeling is low, so the content is 1% by mass or more, preferably 2% by mass or more, and more preferably 5% by mass or more. preferable. In addition, when the content of the component (b) exceeds 15% by mass, not only does it have stickiness but also the elongation and skin conformity deteriorate, so the content is 15% by mass or less, preferably 12% by mass or less, preferably 10% by mass. The following is more preferable.

[(C) component]
The liquid oil which is component (c) can be used for ordinary cosmetics and can be used without particular limitation as long as it is liquid at ordinary temperature (25 ° C.).

  The oil that is liquid at room temperature as component (c) is, for example, hydrocarbon oils such as liquid paraffin and squalane hydrogenated polyisobutene; silicones such as methylpolysiloxane, methylphenylpolysiloxane, methylhydrogenpolysiloxane, and methylcyclopolysiloxane. Triglycerides such as olive oil, sunflower oil, triethylhexanoin; ester oils such as octyldodecyl myristate, ethylhexyl palmitate, pentaerythrityl tetraethylhexanoate, jojoba oil, and the like. One or more of these liquid oils can be used. Of these, triglycerides and ester oils are preferably used.

  As the component (c), it is more preferable to use a combination of ester oil and triglyceride. In this case, the blending ratio of triglyceride and ester oil is 1:10 to 10: 1, more preferably 1: 5 to 5: 1 as a weight ratio. If the amount of triglyceride is less than 0.1 times that of ester oil, the familiarity with the skin will be worse, and if it is more than 10 times, the elongation will be worse.

  The content of the component (c) in the oil-in-water emulsified skin cosmetic of the present invention is 1 to 25% by mass. When the content of the component (c) is less than 1% by mass, the thickness at the time of application is impaired, and the elongation and skin familiarity are deteriorated, and the durability of the moisturizing feeling is also weakened. For this reason, although content of (c) component shall be 1 mass% or more, 4 mass% or more is preferable and 6 mass% or more is still more preferable. Further, if the content of the component (c) exceeds 25% by mass, it causes sliminess and stickiness, so it is 25% by mass or less, preferably 20% by mass or less, more preferably 18% by mass or less, and 15% by mass. % Or less is even more preferable.

[Component (d)]
The component (d) is a nonionic surfactant that is generally used in cosmetics. It is preferable that HLB of (d) component is 2-16.
HLB is an abbreviation for Hydrophile-Lipophile Balance, and is a concept in which the balance of hydrophilic groups and lipophilic groups of a surfactant is quantified. Generally, 0 to 20 is indicated, and a higher numerical value indicates higher hydrophilicity.
The HLB is calculated by any one of the following formulas (5) to (6) proposed by Griffin.
POE alkyl ether type

HLB = weight fraction of oxyethylene group / 5 (5)
Polyhydric alcohol fatty acid ester type and polyglycerin type nonionic surfactant

HLB = 20 (1-S / A) (6)

S: Saponification value of ester, A: Acid value of fatty acid (Source: Surfactant Handbook, Engineering Book Co., Ltd.)

  Examples of the component (d) include glycerin fatty acid ester, sorbitan fatty acid ester, polyglycerin fatty acid ester, polyoxyethylene alkyl ether, and polyoxyalkylene fatty acid ester. One or two or more selected from these can be used. In particular, it is preferable to combine one or more nonionic surfactants having an HLB of less than 10 and one or more nonionic surfactants having an HLB of 10 or more. This is because the emulsion stability is excellent and the thickness and elongation of the preparation are improved.

Examples of the nonionic surfactant having an HLB of less than 10 include glyceryl monostearate and sorbitan monostearate. Examples of the nonionic surfactant having an HLB of 10 or more include polyoxyethylene (20) sorbitan monostearate.
The mixing ratio of the nonionic surfactant having an HLB of less than 10 and the nonionic surfactant having an HLB of 10 or more is from 1:10 to 10: 1, more preferably from 1: 5 to 5: 1 as a weight ratio. When the amount of the nonionic surfactant having an HLB of less than 10 is less than 0.1 times or more than 10 times the amount of the nonionic surfactant having an HLB of 10 or more, the emulsion stability is poor.

  Commercially available products of component (d) include glyceryl monostearate (HLB; 3.0) (“Sunsoft No. 2500-C” manufactured by Taiyo Kagaku), polyoxyethylene (20 mol) sorbitan monostearate (HLB; 14.9). ) ("Sorbon T-60" manufactured by Toho Chemical Industry Co., Ltd.).

  The content of the component (d) in the oil-in-water emulsified skin cosmetic of the present invention is 1 to 10% by mass. When the content of the component (d) is less than 1% by mass, the thickness at the time of coating is impaired, so that it is 1% by mass or more, preferably 2% by mass or more, and more preferably 4% by mass or more. On the other hand, when the content of the component (d) is more than 10% by mass, the skin becomes unsuitable and causes stickiness. For this reason, although content of (d) component shall be 10 mass% or less, 8 mass% or less is preferable and 6 mass% or less is still more preferable.

  The skin cosmetics of the present invention can be suitably prepared according to the type of cosmetics and pharmaceuticals to be prepared using the components (a), (b), (c) and (d). For example, skin cosmetics and pharmaceuticals such as emulsions, creams, ointments, packs, and foundations can be prepared by known methods.

The skin cosmetic of the present invention can be blended with additives commonly used in cosmetics and pharmaceuticals as long as the performance of the oil-in-water emulsified skin cosmetic of the present invention is not impaired. From this viewpoint, the total amount of additives in the oil-in-water emulsified skin cosmetic of the present invention is preferably 15% by mass or less, and more preferably 8% or less.
When the amount of the oil-in-water emulsified skin cosmetic of the present invention is 100% by mass, the amount of water is the balance of the amounts of components (a) to (d) and the amount of additives.

  Examples of such additives include lower alcohols such as ethanol and isopropyl alcohol; polyhydric alcohols other than the component (b) in the present invention such as propylene glycol, polyethylene glycol, sorbitol, maltitol, and isomaltitol; lactose, fructose, Sugars such as sucrose; Hydrocarbon oils such as petroleum jelly and solid paraffin; Natural fats and oils such as beef tallow, lard and fish oil; Fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid and oleic acid; beeswax, carnauba wax, etc. Waxes; silicone derivatives such as highly polymerized dimethylpolysiloxane, polyether-modified dimethylpolysiloxane, amino-modified dimethylpolysiloxane; oily bases such as ceramide, cholesterol, protein derivatives, lanolin, lanolin derivatives, lecithin; soap, acylmethylta Anionic surfactants such as phosphorus salts and amide ether sulfates; amphoteric surfactants such as amide amino acid salts and amidopropyldimethylaminoacetic acid betaines; cationic surfactants such as alkyltrimethylammonium chloride; alkyldimethylamines Semipolar surfactants such as oxides; Organic or inorganic salts such as pyrrolidone carboxylates and salt; Acids and alkalis as pH adjusters; Bactericides; Antioxidants; Blood circulation promoters; UV absorbers; Natural extracts derived from animals and plants; vitamins; amino acids; photosensitizers; dyes; pigments and fragrances.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. In addition, about various physical-property values, it measured by the method shown below.

_<M L, _{M H} and As values>
Showa Denko GPC (gel permeation chromatography) using a measuring device, Fig. 1, in accordance with the method described in reference to FIG. 2, was determined M _L, M _H and As.

[Preparation of component (a)]
Combined with 200 g of butyl propylene glycol in a stainless steel 5 liter (internal volume 4,890 ml) pressure-resistant reactor equipped with a thermometer, pressure gauge, safety valve, nitrogen gas blowing pipe, stirrer, vacuum exhaust pipe, cooling coil and steam jacket 0.2 g of metal cyanide complex catalyst was charged. After nitrogen substitution, the temperature was raised to 110 ° C., and 210 g of methyloxirane was charged from a nitrogen gas blowing tube over 4 hours under the condition of 0.3 MPa or less. At this time, changes in pressure and temperature in the reaction tank over time were measured.

  After 4 hours, the pressure in the reaction vessel suddenly decreased. Thereafter, while maintaining the inside of the reaction vessel at 110 ° C., methyl oxirane was gradually added from a nitrogen gas blowing tube under the condition of 0.6 MPa or less, and 3,287 g of methyl oxirane was continuously added under stirring. did. At this time, the time until 840 g of methyloxirane was added was 60 minutes, the time until 2,100 g was added was 108 minutes, and the time until 3,287 g was added was 132 minutes.

  After completion of the addition, the mixture was reacted at 110 ° C. for 1 hour, and 1,680 g was extracted from the reaction vessel. The residue in the reaction vessel was heated to 110 ° C., and 696 g of methyloxirane was added from a nitrogen gas blowing tube over 77 minutes under the condition of 0.6 MPa or less. After completion of the addition, the reaction was carried out at 110 ° C. for 1 hour, and then 1,188 g was again extracted from the reaction vessel, and filtered under reduced pressure at 75 to 85 ° C. and 50 to 100 Torr for 1 hour while blowing nitrogen gas.

  Further, the temperature of the residue in the reaction vessel was raised to 110 ° C., and 291 g of methyl oxirane was added from a nitrogen gas blowing tube over 35 minutes under the condition of 0.6 MPa or less while maintaining the inside of the reaction vessel at 110 ° C. After completion of the addition, the reaction was carried out at 110 ° C. for 1 hour, and then 752 g was extracted from the reaction vessel again, and filtered under reduced pressure at 75 to 85 ° C. and 50 to 100 Torr for 1 hour while blowing nitrogen gas. Further, the temperature of the residue in the reaction vessel was raised to 110 ° C., and 174 g of methyloxirane was added from a nitrogen gas blowing tube over 20 minutes under the condition of 0.6 MPa or less while maintaining the inside of 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 extracted from the reaction vessel again, and filtered under reduced pressure at 75 to 85 ° C. and 50 to 100 Torr for 1 hour while blowing nitrogen gas.

The obtained reaction product (high molecular weight alkyloxirane derivative 1) was measured by gel permeation chromatography. As a _{result, M} L / M _H is 0.52, As was 0.61.

Further, the temperature of the residue in the reaction vessel was raised to 110 ° C., and 121 g of methyloxirane was added from a nitrogen gas blowing tube over 30 minutes under the condition of 0.6 MPa or less while keeping the inside of the reaction vessel at 110 ° C. After completion of the addition, the mixture was reacted at 110 ° C. for 1 hour, and then 370 g was extracted from the reaction vessel again, and filtered under reduced pressure at 75 to 85 ° C. and 50 to 100 Torr for 1 hour while blowing nitrogen gas. The obtained reaction product (high molecular weight alkyloxirane derivative 2) was measured by gel permeation chromatography. As a _{result, M} L / M _H is 0.42, As was 0.59.

Further, the temperature of the residue in the reaction vessel was raised to 110 ° C., and 122 g of methyloxirane was added from a nitrogen gas blowing tube over 30 minutes under the condition of 0.6 MPa or less while keeping the inside of the reaction vessel at 110 ° C. After making it react at 110 degreeC for 1 hour, it filtered after 75-85 degreeC and pressure reduction processing at 50-100 Torr for 1 hour, blowing in nitrogen gas. The obtained reaction product (high molecular weight alkyloxirane derivative 3) was measured by gel permeation chromatography. As a _{result, M} L / M _H is 0.36, As was 0.57.

[Examples 1-6, Comparative Examples 1-4]
Oil-in-water emulsified skin cosmetics were prepared by the following method at the blending ratios shown in Table 1. The common additive components in Table 1 are the four components shown in Table 2.

  That is, the aqueous phase containing the component (b) and ion-exchanged water, and the oil component composed of the component (a), the component (c), the component (d), and the common additive component are mixed and heated to 75 to 80 ° C. Then, the mixture was cooled using a homomixer and then cooled, and the preservative in the common additive components was added to obtain an oil-in-water emulsified cream skin cosmetic.

  Using the obtained skin cosmetics, 5 items were evaluated according to the following evaluation criteria. The evaluation results are shown in Table 1.

[Evaluation items and evaluation criteria]
(1) Thickness at the time of application
20 males and females (24-58 years old) were panelists, and after washing their face, the thickness when applied immediately after the use of skin cosmetics was determined as follows, and the average value of 20 persons was determined. went.

5 points: Thickness is fully felt 4 points: Thickness is slightly felt 3 points: Cannot be said to be 2 points: Thickness is hardly felt 1 point: Thickness is not felt at all

(2) Elongation during application
20 males and females (24-58 years old) are panelists, and after washing their faces, the elongation when applied immediately after using skin cosmetics is determined as follows, and the average value of 20 persons is determined. went.

5 points: easy to expand 4 points: relatively easy to expand 3 points: cannot be said to be 2 points: relatively difficult to expand 1 point: difficult to expand

(3) Skin familiarity
20 males and females (24-58 years old) were panelists, and after washing the skin, it was judged as follows about skin familiarity when applied immediately after using skin cosmetics, and the average value of 20 people was obtained and judged Went.

5 points: good familiarity to skin 4 points: slightly familiar to skin 3 points: cannot be said 2 points: slightly familiar to skin 1 point: poorly familiar to skin

(4) Stickiness
20 males and females (24-58 years old) were panelists, and after washing their face, using skin cosmetics, the skin feel after 10 minutes was determined as follows, and the average value of 20 persons was determined. went.

5 points: I don't feel sticky 4 points: I feel slightly sticky 3 points: I can't say either 2 points: I feel sticky 1 point: I feel sticky strongly

(5) Sustainability of moisture retention
20 males and females (24-58 years old) were panelists, and after washing their face, using skin cosmetics, the skin feel after 12 hours was judged as follows, and the average value of 20 people was determined. Went.

5 points: Feeling the sustainability of moisturizing feeling 4 points: Feeling the sustainability of moisturizing feeling a little 3 points: Not being able to say 2 points: Sustaining moisturizing feeling is almost impossible 1 point: Sustaining moisturizing feeling I can't feel at all

[Criteria]
◎: Average score is 4.0 or more ○: Average score is 3.5 or more and less than 4.0 △: Average score is 3.0 or more and less than 3.5 ×: Average score is 2.5 or more and less than 3.0

Note 1: "PREMINOL S1004F" (Asahi Glass Co., _{Ltd.) (M L / M H =} 1.05, As = 0.97)
Note 2: "Sunsoft No. 2500-C" (manufactured by Taiyo Chemical Co., Ltd.)
Note 3: "Sorbon T-60" (manufactured by Toho Chemical Co., Ltd.)

  From Examples 1 to 6, all the creams using the ingredients according to the present invention were stretched while being thick when applied, had good skin fit, no stickiness, and excellent moisturizing feeling. .

On the other hand, in Comparative Examples 1-4, sufficient effect is not acquired.
That is, in Comparative Example 1, since the component (a) is not blended, the thickness at the time of application is insufficient, the familiarity with the skin is somewhat bad, and the sustainability of the moisturizing feeling is also weak.
In Comparative Example 2, since the alkyloxirane derivative 4 having a high M _L / M _H and As is blended in place of the component (a), not only the thickness is insufficient, but also the durability of the moisturizing feeling is maintained. It is weak.

On the other hand, in Comparative Example 3, since the component (b) is not blended, the thickness at the time of application is slightly deteriorated and the sustainability of the moisturizing feeling is weakened.
In Comparative Example 4, since the amount of the component (c) is less than 1% by mass, elongation at the time of application and skin conformability are deteriorated.

Claims (1)

(A) 0.1 to 10% by mass of a high molecular weight alkyloxirane derivative defined below, (b) 1 to 15% by mass of a polyhydric alcohol having 2 to 6 carbon atoms, and (c) 1 to An oil-in-water emulsified skin cosmetic comprising 25% by mass and (d) 1 to 10% by mass of a nonionic surfactant.

(A) An alkyloxirane derivative represented by the following formula (1) and satisfying the relationship of the following formula (2), formula (3) and formula (4)

R ¹ O— (AO) n—H (1)

(In the formula (1),
R ¹ represents a hydrocarbon group having 1 to 22 carbon atoms,
AO represents an oxyalkylene group having 3 carbon atoms,
n represents a number of 25 or more. )

_{0.35 ≦ M L / M H ≦} 0.75 ···· (2)

(In Formula (2), the length of the perpendicular from the maximum point K to the base line B where the refractive index intensity on the chromatogram obtained by gel permeation chromatography measurement is maximum is L, and the refractive index intensity is L / 2. Of the two points on the chromatogram, the point with the earlier elution time is point O, the point with the later elution time is point Q, and the line G connecting point O and point Q and the maximum point K are drawn to the baseline. when the intersection of the perpendicular is P was the distance between the point O and the intersection P and M _H, the distance between the point Q and the point of intersection P and M _L.)

As = W _1/2 / W _5% (3)

0.30 ≦ As ≦ 0.70 (4)

(In the formula (3), the point where the elution time is early among the two points where the refractive index intensity is L / 20 on the chromatogram is point R, the point where the elution time is late is point S, and point R and point S Let T be the intersection of the straight line H connecting the line H and the perpendicular drawn from the local maximum K to the base line B, the distance between the point R and the intersection T is W _1/2 , and the distance between the point R and the point S is W _5% And)

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