Skin cosmetic

Abstract

To provide a skin cosmetic that offers excellent compatibility and, after application, forms a film having high effects in sebum absorption.SOLUTION: A skin cosmetic comprises the following components (A), (B), (C), and (D): (A) a polymer having a cellulose backbone in which substituents selected from a hydroxypropyl group, a hydroxybutyl group, and an amide group are substituted at 2.4 or more sites per glucose; (B) one or more surfactants selected from alkyl glyceryl ethers and sorbitan fatty acid esters; (C) one or more selected from polyhydric alcohols and ethanol; and (D) water.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to skin cosmetics.

Background Art

[0002] Conventionally, among sebum, as the effects on the skin caused by unsaturated fatty acids such as oleic acid, 8Z-octadecenoic acid, petroselinic acid, vaccenic acid, and palmitoleic acid, mild inflammation, surface roughness, prominent unevenness such as pores, makeup collapse, stickiness, etc. are known. In order to improve the effects of such unsaturated fatty acids on the skin, various studies have been conducted. For example, Patent Document 1 describes that an emulsified composition containing a polymer having a specific cellulose skeleton, a dihydric alcohol, and one or more compounds selected from sphingosine, a salt of sphingosine, pseudo-sphingosine, a salt of pseudo-sphingosine, an anionic surfactant, and a cationic surfactant has a high effect of suppressing skin roughness caused by sebum. Patent Document 2 describes that a cosmetic containing a polymer having a specific cellulose skeleton, a dihydric alcohol, and a water-soluble polymer having a carboxyl group has a high effect of suppressing skin roughness caused by sebum.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, although conventional cosmetics have a sebum adsorption effect on oleic acid, their effects on other components contained in sebum are not sufficient, and the sebum adsorption effect is not sufficiently satisfactory. On the one hand, hydroxypropyl cellulose and its derivatives have been conventionally used as water-soluble thickeners in pharmaceuticals, cosmetics, and the like. However, hydroxypropyl cellulose is prone to aggregation when dissolved in water, and there are problems with compatibility.

Means for Solving the Problems

[0005] The present inventors have found that by using in combination a polymer having a specific cellulose skeleton, one or more surfactants selected from alkyl glyceryl ethers and sorbitan fatty acid esters, polyhydric alcohols, etc., a skin cosmetic with good compatibility and a film formed after application having a high sebum adsorption effect can be obtained.

[0006] The present invention relates to the following components (A), (B), (C), and (D): (A) A polymer having a cellulose skeleton in which substituents selected from hydroxypropyl groups, hydroxybutyl groups, and amide groups are substituted at 2.4 or more per glucose. (B) One or more surfactants selected from alkyl glyceryl ethers and sorbitan fatty acid esters. (C) One or more selected from polyhydric alcohols and ethanol. (D) Water It relates to a skin cosmetic containing the same.

Effects of the Invention

[0007] The skin cosmetic of the present invention is excellent in compatibility, and the film formed after application has a high sebum adsorption effect.

Brief Description of the Drawings

[0008]

Figure 1

Modes for Carrying Out the Invention

[0009] Component (A) used in the present invention is a polymer having a cellulose skeleton, in which the substituents selected from a hydroxypropyl group, a hydroxybutyl group, and an amide group are substituted 2.4 or more per glucose unit. Component (A) is one in which the substituents selected from a hydroxypropyl group, a hydroxybutyl group, and an amide group are substituted 2.4 or more per glucose unit (degree of substitution of 2.4 or more) on the hydroxyl groups of cellulose, and the degree of substitution is preferably 3 or more. Here, the degree of substitution is the average number of substituted hydroxyl groups per glucose unit. When the substituents such as a hydroxypropyl group also contain hydroxyl groups, the hydroxyl groups of those substituents are also etherified during the reaction, and the molar degree of substitution, which is the number of substituents per glucose unit, becomes larger than 3, for example, in the case of a hydroxypropyl group. As component (A), hydroxypropyl cellulose is preferable from the viewpoints of improving compatibility, improving the sebum adsorption effect of the film formed after coating, and gelling unsaturated fatty acids. Moreover, the polymer of component (A) preferably has no substituents other than a hydroxypropyl group, a hydroxybutyl group, and an amide group.

[0010] Also, from the viewpoints of improving compatibility, improving the sebum adsorption effect of the film formed after coating, and gelling unsaturated fatty acids, component (A) preferably has an average molecular weight of 40,000 to 2,500,000, and more preferably 100,000 to 2,500,000. Here, the average molecular weight is measured by GPC (Gel Permeation Chromatograph).

[0011] Such polymers can be produced, for example, by adding propylene oxide to alkali cellulose activated by mercerization. For example, hydroxypropyl cellulose, in which the substituent is a hydroxypropyl group, is produced by subjecting cellulose to a very complicated activation treatment called so-called mercerization or alkalization, in which cellulose is mixed in a slurry state with a large amount of water and a large excess of an alkali metal hydroxide such as sodium hydroxide to form alkali cellulose, and then allowing propylene oxide to act on this alkali cellulose.

[0012] As the component (A), for example, commercially available products such as HPC-SSL, HPC-SL, HPC-L, HPC-M, HPC-H, HPC-VH (manufactured by Nippon Soda Co., Ltd.), KLUCEL MF Pharm, and KLUCEL HPC (manufactured by Ashland) can be used.

[0013] The component (A) can be used alone or in combination of two or more. From the viewpoints of improving the blendability and the sebum adsorption effect of the film formed after coating, the content is preferably 0.01 to 5% by mass, more preferably 0.15 to 3% by mass, and still more preferably 0.3 to 1.5% by mass in the total composition.

[0014] The component (B) is one or more surfactants selected from alkyl glyceryl ethers and sorbitan fatty acid esters. Examples of the alkyl glyceryl ether include those having an alkyl group with 8 to 24 carbon atoms constituting the alkyl glyceryl ether, such as mono-2-ethylhexyl glyceryl ether, monodecyl glyceryl ether, monolauryl glyceryl ether, monomyristyl glyceryl ether, monocetyl glyceryl ether, monostearyl glyceryl ether, monoisostearyl glyceryl ether, monooleyl glyceryl ether, and monobehenyl glyceryl ether. Among these, from the viewpoint of improving the sebum adsorption effect of the film formed after application, the number of carbon atoms of the alkyl group constituting the alkyl glyceryl ether is preferably 12 to 22, more preferably 16 to 18, and still more preferably 18. Further, as the alkyl glyceryl ether, it preferably contains one or more selected from monocetyl glyceryl ether, monostearyl glyceryl ether, monoisostearyl glyceryl ether, monooleyl glyceryl ether, and monobehenyl glyceryl ether, more preferably contains one or more selected from monoisostearyl glyceryl ether and monooleyl glyceryl ether, still more preferably contains monoisostearyl glyceryl ether.

[0015] In addition, examples of the sorbitan fatty acid ester include those in which the number of carbon atoms of the fatty acid residue constituting the sorbitan fatty acid ester is 8 to 26, such as sorbitan monolaurate, sorbitan monomyristate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monoisostearate, sorbitan monooleate, sorbitan monobehenate, sorbitan dioleate, and the like. Among these, from the viewpoint of improving the sebum adsorption effect of the film formed after application, the number of carbon atoms of the fatty acid residue constituting the sorbitan fatty acid ester is preferably 12 to 24, more preferably 16 to 22, still more preferably 16 to 18, and even more preferably 18. Further, as the sorbitan fatty acid ester, it preferably contains one or more selected from sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monoisostearate, and sorbitan monooleate, more preferably contains one or more selected from sorbitan monostearate, sorbitan monoisostearate, and sorbitan monooleate, still more preferably contains one or more selected from sorbitan monoisostearate and sorbitan monooleate, and even more preferably contains sorbitan monoisostearate.

[0016] As component (B), from the viewpoints of improving blendability and improving the sebum adsorption effect of the film formed after application, it is preferably included sorbitan fatty acid esters, more preferably includes one or more selected from sorbitan monostearate, sorbitan monoisostearate, sorbitan monooleate, and even more preferably includes sorbitan monoisostearate.

[0017] Component (B) can be used singly or in combination of two or more, and the content is preferably 0.005 to 2.3% by mass, more preferably 0.2 to 1.8% by mass, even more preferably 0.3 to 1.5% by mass in the total composition from the viewpoints of improving blendability and improving the sebum adsorption effect of the film formed after application.

[0018] The skin cosmetic of the present invention can contain a surfactant other than component (B). The content of the total surfactant containing component (B) is preferably 0.001 to 7% by mass, more preferably 0.005 to 5% by mass, even more preferably 0.01 to 3% by mass, and still more preferably 0.015 to 2.5% by mass in the total composition from the viewpoint of improving blendability.

[0019] In the present invention, the mass ratio (B) / (A) of component (B) to component (A) is preferably 0.1 to 10, more preferably 0.2 to 5, even more preferably 0.4 to 2.6, and still more preferably 0.6 to 1.8 from the viewpoints of improving blendability and improving the sebum adsorption effect of the film formed after application.

[0020] Component (C) is one or more selected from polyhydric alcohols and ethanol. Examples of the polyhydric alcohol include those commonly used in ordinary cosmetics, such as dihydric alcohols like propylene glycol, 1,3-butylene glycol, 1,3-propanediol, dipropylene glycol, polyethylene glycol, tripropylene glycol, polypropylene glycol, glycerin, trimethylolpropane; polyglycerins such as diglycerin, polyglycerin-10, and polyhydric alcohols with three or more hydroxyl groups such as erythritol. Among these, from the viewpoint of improving compatibility, it is preferable to contain one or more selected from propylene glycol, dipropylene glycol, 1,3-butylene glycol, 1,3-propanediol, glycerin, diglycerin, and polyglycerin; more preferably to contain one or more selected from propylene glycol, dipropylene glycol, glycerin, and polyglycerin; even more preferably to contain one or more selected from dipropylene glycol and polyglycerin; and still more preferably to contain one or more selected from dipropylene glycol and polyglycerin-10.

[0021] Component (C) preferably contains one or more selected from dihydric alcohols and ethanol; more preferably contains one or more selected from dipropylene glycol, polyglycerin, and ethanol; even more preferably contains one or more selected from dipropylene glycol, polyglycerin-10, and ethanol; and still more preferably contains ethanol.

[0022] Component (C) can be used in combination of one or more kinds, and the content is preferably 0.1 to 25% by mass, more preferably 0.5 to 15% by mass, even more preferably 0.8 to 8% by mass, and still more preferably 1.5 to 6% by mass in the total composition, from the viewpoints of improving compatibility and improving the sebum adsorption effect of the film formed after application.

[0023] In the present invention, the mass ratio (A) / (C) of component (A) to component (C) is preferably from 0.001 to 5, more preferably from 0.027 to 2, still more preferably from 0.04 to 1, and even more preferably from 0.07 to 0.5, from the viewpoints of improving compatibility and improving the sebum adsorption effect of the film formed after application.

[0024] In the present invention, the mass ratio (B) / (C) of component (B) to component (C) is preferably from 0.0005 to 1, more preferably from 0.0007 to 0.37, still more preferably from 0.001 to 0.3, even more preferably from 0.04 to 0.25, and still even more preferably from 0.06 to 0.15, from the viewpoints of improving compatibility and improving the sebum adsorption effect of the film formed after application.

[0025] The water content of component (D) is preferably 70 to 99% by mass, more preferably 86 to 98% by mass in the total composition, from the viewpoint of improving compatibility.

[0026] In addition to the above components, the skin cosmetic of the present invention can contain components usually used in ordinary cosmetics, such as oily components, polymer compounds other than component (A), powders, antioxidants, fragrances, preservatives, pH adjusters, blood circulation promoters, cooling agents, antiperspirants, bactericides, skin activators, moisturizing agents other than component (C), refreshing agents, and the like.

[0027] The skin cosmetic of the present invention can be produced according to a usual method. For example, component (A) and a part of water are mixed and stirred at a high temperature, and after confirming that they are uniform, they are cooled to room temperature to prepare an aqueous solution containing component (A). After adding component (C) to component (B) and mixing them uniformly, the remaining water, the aqueous solution containing component (A) and other components are further mixed to produce a skin cosmetic. The skin cosmetic of the present invention is suitable as a leave-on type skin cosmetic such as lotion and essence. Further, the skin cosmetic of the present invention is preferably in a liquid state and is suitable as a lotion.

[0028] When the skin cosmetic of the present invention is in a liquid state (lotion), the viscosity at 25°C is preferably 50 to 40,000 mPa·s, more preferably 500 to 20,000 mPa·s, even more preferably 1,000 to 10,000 mPa·s, and still more preferably 1,200 to 6,000 mPa·s. The viscosity is the value measured by the following method for the viscosity immediately after production. Less than 1,000 mPa·s is measured at 25°C with a B-type viscometer rotor No. 1, 6 rpm. 1,000 mPa·s or more and less than 5,000 mPa·s is measured at 25°C with a B-type viscometer rotor No. 2, 6 rpm. 5,000 mPa·s or more and less than 20,000 mPa·s is measured at 25°C with a B-type viscometer rotor No. 3, 6 rpm. 20,000 mPa·s or more is measured at 25°C with a B-type viscometer rotor No. 4, 6 rpm.

Examples

[0029] Examples 1 to 18 and Comparative Examples 1 to 3 Skin cosmetics having the compositions shown in Table 1 were produced and evaluated for compatibility and sebum adsorption after film formation. The results are shown together in Table 1.

[0030] (Production method) (1) Preparation of hydroxypropyl cellulose aqueous solution: 5 g of hydroxypropyl cellulose powder of component (A) was added to 95 g of water at 80°C, stirred uniformly, and then gradually cooled to prepare an aqueous solution. (2) Preparation of cosmetic: At 25°C, component (C) was added to component (B), uniformly mixed, and then further water was added and uniformly mixed. The hydroxypropyl cellulose aqueous solution of (1) was added to obtain the skin cosmetic by stirring for 3 minutes so as to have the content of component (A) in each example.

[0031] (Evaluation method) (1) Compatibility: (1-1) Preparation of hydroxypropyl cellulose aqueous solution: 5 g of hydroxypropyl cellulose powder of component (A) is added to 95 g of water at 80°C, stirred uniformly, and then gradually cooled to prepare an aqueous solution. (1-2) Preparation of cosmetics: At 25°C, component (C) is added to component (B) and mixed uniformly. Then, water is further added and mixed uniformly. Further, the hydroxypropyl cellulose aqueous solution of (1) is added to achieve the content of component (A) in each example, and stirred for 3 minutes. (1-3) The appearance of each obtained skin cosmetic was visually evaluated according to the following criteria. 3: No aggregation. 2: Slight aggregates. 1: Obvious aggregates.

[0032] (2) Sebum adsorption after film formation: (2-1) 400 mg (20 mg / cm 2 ) of each skin cosmetic was uniformly applied to the entire surface of a 76 mm × 26 mm slide glass (model number: S2111, manufactured by Matsunami Glass Industry Co., Ltd.). (2-2) The slide glass of (2-1) was left standing at 25°C and 75% humidity for 24 hours to dry the skin cosmetic applied on the slide glass to form a coating film. (2-3) To the coating film dried on the slide glass of (2-2), 20 μL of each of the following 4 types of mixed sebum was dropped. In the mixed sebum, Sudan III (red coloring agent) was included at 0.1% in the mixed sebum to be colored red. The reason for coloring red is to visually confirm whether the coating film with the dropped mixed sebum remains or not when the dried coating film is wiped off with a Kimwipe in the following operation of (2-4). · Mixed sebum A: 10% oleic acid (OA), 45% triglyceride (TAG), 45% squalane (SQ), · Mixed sebum B: 30% OA, 35% TAG, 35% SQ, · Mixed sebum C: 50% OA, 25% TAG, 25% SQ, · Mixed sebum D: 70% OA, 15% TAG, 15% SQ,

[0033] Five minutes after the operation of (2-4)(2-3), the entire slide glass of (2-3) was wiped off with a Kimwipe with a constant force, and it was visually evaluated from the red coloring whether the coating film with the mixed sebum dropped on the slide glass plate remained or not. When the red color remains on the slide glass, it indicates that the mixed sebum is retained (trapped) in the coating film. When the red color does not remain, it indicates that the mixed sebum cannot be retained in the coating film. Also, the lower the ratio of oleic acid (OA) in the mixed sebum (mixed sebum A), the more the coloring remains, indicating a higher ability to retain the mixed sebum (trap ability).

[0034] (2-5) The red color remaining on the slide glass with the mixed sebum was evaluated according to the following criteria. (See Figure 1) 5: The red color of all of mixed sebum A, B, C, and D remains. (High sebum trapping ability) 4: The red color of mixed sebum B, C, and D remains. 3: The red color of mixed sebum C and D remains. 2: The red color remains only on mixed sebum D. 1: The red color does not remain on any of mixed sebum A, B, C, and D. (Low sebum trapping ability)

[0035]

Table 1

[0036] *1 Hydroxypropyl cellulose: HPC-H (manufactured by Nippon Soda Co., Ltd.), *2 Hydroxypropyl cellulose: HPC-L (manufactured by Nippon Soda Co., Ltd.), *3 Hydroxypropyl cellulose: HPC-SSL (manufactured by Nippon Soda Co., Ltd.), *4 Monoisostearyl glyceryl ether: GE-IS (manufactured by Kao Corporation), *5 Sorbitan monoisostearate: Span 120-LQ-(RB) (manufactured by Croda Europe Ltd), *6 Polyglycerin: Polyglycerin #750 (Cosmetic Name: Polyglycerin - 10) (Manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.)

[0037] Formulation Example 1 The skin cosmetic with the composition shown in Table 2 is excellent in compatibility and has a high sebum adsorption capacity.

[0038]

Table 2

Claims

Claim 1 The following components (A), (B), (C) and (D): (A) A polymer having a cellulose backbone, wherein the number of substituents selected from a hydroxypropyl group, a hydroxybutyl group and an amide group is 2.4 or more per glucose; (B) At least one surfactant selected from alkyl glyceryl ether and sorbitan fatty acid ester; (C) At least one selected from polyhydric alcohols and ethanol; (D) Water A skin cosmetic containing the same. Claim 2 The skin cosmetic according to Claim 1, wherein the mass ratio (B) / (A) of component (B) to component (A) is 0.1 to 10. Claim 3 The skin cosmetic according to Claim 1 or 2, wherein the content of component (A) is 0.01 to 5% by mass. Claim 4 The skin cosmetic according to Claim 1 or 2, wherein component (A) is hydroxypropyl cellulose.

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