HK1164723B - Oil-in-water emulsion composition - Google Patents

Description

Oil-in-water type emulsion composition

Technical Field

The present invention relates to a base for cosmetics which gives a moist touch when applied and has excellent water resistance after application, and further relates to a skin care cosmetic, particularly a sunscreen cosmetic, using the base.

Background

Although oil-in-water emulsions, which have been conventionally used as bases for various cosmetics, are excellent in terms of a feeling of use in imparting a water-wet touch thereto, they have a disadvantage that they are satisfactory in terms of water resistance.

As an attempt to improve the water resistance of an oil-in-water emulsion cosmetic, for example, patent document 1 discloses a cosmetic containing an oil-in-water emulsion containing an α -monoalkyl glyceryl ether, a wax and a silicone oil, wherein the water resistance is improved and the makeup retention is improved by adjusting the amount of the silicone oil in the oil phase to a specific range and containing a hydrophobized powder.

Patent document 2 discloses an oil-in-water emulsion cosmetic in which zinc oxide, an acrylic crosslinked copolymer, a nonionic or anionic surfactant having an HLB10 or more, water, and a silicone oil are blended and zinc oxide is dispersed in an oil phase, and describes that storage stability, transparency after use, and water resistance are improved.

On the other hand, there is a problem that when an alcohol is blended in a large amount, emulsified particles are broken and it is difficult to obtain a sufficiently stable base, and patent document 3 discloses an alcohol/oil-in-water type emulsion composition containing an oil component, 50 wt% or more of a lower alcohol, water, and one or two or more kinds of polyether-modified silicones represented by the following general formula as an emulsifier, and substantially not containing other surfactants as an emulsifier; it is also described that the composition imparts luster, softness, and a moist feel to hair and has an effect of facilitating the combing of hair.

(in the formula, m is an integer of 50 to 1000, n is an integer of 1 to 40, a is an integer of 5 to 50, and b is an integer of 5 to 50).

However, the composition described in patent document 3 cannot be used in a general skin care base because it contains a large amount of lower alcohol.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2002-308730

Patent document 2: japanese patent laid-open publication No. 2005-272389

Patent document 3: international publication WO97/002888 pamphlet

Disclosure of Invention

Problems to be solved by the invention

Accordingly, an object of the present invention is to provide an oil-in-water emulsion base which is stable even when ethanol is blended in a large amount (but 50% by mass or less) and exhibits excellent water resistance after being applied to the skin or the like.

Means for solving the problems

The present inventors have conducted extensive studies to solve the above problems, and as a result, have found that the above problems can be solved by using a polyether-modified silicone having an hlb (si) of 5 to 10 as a surfactant, and blending 5 to 50 mass% or less of ethanol, and further blending a specific amount of a hydrophilic thickener and a polyol to prepare an oil-in-water emulsion, and have completed the present invention.

Herein, hlb (si) is a value obtained according to the following calculation formula.

Namely, the present invention provides an oil-in-water type emulsion cosmetic characterized by containing

(A)0.1 to 10 mass% of a polyether-modified silicone having an HLB (Si) of 5 to 10,

(B)5 to 50 mass% or less of ethanol,

(C)0.01 to 3 mass% of a hydrophilic thickener, and

(D)0.1 to 15 mass% or more of a polyhydric alcohol.

ADVANTAGEOUS EFFECTS OF INVENTION

The emulsion cosmetic of the present invention is an oil-in-water emulsion containing a large amount of ethanol, and therefore can provide a moist feeling of use. On the other hand, since the phase change occurs with evaporation of ethanol after application to the skin or the like, and the water-in-oil type ink is converted to a water-in-oil type, excellent water resistance can be exhibited.

Further, when the emulsion cosmetic of the present invention is used as a base and an ultraviolet absorber is added, not only is the water resistance excellent, but also the ultraviolet shielding effect is excellent.

Drawings

FIG. 1 is a graph showing the ultraviolet shielding effect of comparative example 4 and comparative example 7.

FIG. 2 is a graph showing the water resistance of the ultraviolet shielding effect of example 4 and comparative example 7.

Detailed Description

The polyether-modified silicone (component A) in the oil-in-water emulsion cosmetic of the present invention is selected from polyether-modified silicones having an HLB (Si) of 5 to 10, preferably 5 to 9.

In the present invention, polyether-modified silicone having a molecular weight of 50000 or more and a hydrophilic group selected from Polyoxyethylene (POE) or polyoxypropylene (POP) is preferably used.

Polyether-modified silicones represented by the following formula are particularly preferred.

In the above formula, m is 50 to 1000, preferably 150 to 1000, and n is 1 to 40. When m is less than 50 and n is less than 1, emulsion stability is poor, and when m exceeds 1000 and n exceeds 40, the obtained composition gives a sticky feeling. In addition, m: n is preferably 200: 1-5: 1, and particularly preferably 60: 1-15: 1.

Further, a is 5 to 50, b is 5 to 50, the content of these polyoxyalkylene groups in the molecule is not particularly limited, and the content of polyoxyalkylene groups is preferably more than 20% by weight of the total molecular weight.

Polyether-modified silicones represented by the above formula have been conventionally used as surfactants for oil-in-alcohol emulsions and water-in-oil emulsions in which ethanol is 50% or more (see, for example, WO97/002888 pamphlet and jp-a-10-306020), and no example is known of their use in oil-in-water emulsions containing a small amount of alcohol.

In the present invention, polyether-modified silicone having hlb (si) of 10 or less, preferably 9 or less is used as a surfactant for an oil-in-water emulsion for the first time, and an oil-in-water emulsion is stably formed in a formulation by adjusting the amount of ethanol to be blended and blending a hydrophilic thickener.

The amount of the polyether-modified silicone (component A) to be blended in the present invention is 0.1 to 10% by mass, preferably 0.1 to 5% by mass, and more preferably 0.1 to 3% by mass. When the amount is less than 0.1% by mass or when the amount is more than 10% by mass, a stable oil-in-water emulsion may not be obtained.

The emulsion cosmetic of the present invention contains 5 mass% or more of ethanol (component B) as an essential component. The amount of ethanol is 5 to 50 mass%, preferably 8 to 50 mass%, more preferably 8 to 40 mass%. When the blending amount is less than 5% by mass, a stable oil-in-water emulsion may not be obtained.

The emulsified cosmetic of the present invention further contains a hydrophilic thickener (component C) as an essential component.

In the present invention, it has been found that a stable emulsion cannot be obtained by simply replacing a conventional surfactant in an oil-in-water emulsion with a polyether-modified silicone having an HLB (Si)10 or less which has been conventionally used in water-in-oil emulsions, and that a stable oil-in-water emulsion can be obtained by blending 5% by mass or more of ethanol and a hydrophilic thickener.

The hydrophilic thickener used in the present invention is not particularly limited as long as it can be used in cosmetics. Examples thereof include natural water-soluble polymers, semi-synthetic water-soluble polymers, and inorganic water-soluble polymers.

Specific examples of the natural water-soluble polymer include plant-based polymers such as gum arabic, tragacanth gum, galactan, guar gum, carob gum (carob gum), karaya gum (karaya gum), carrageenan, pectin, agar, quince seed (marmelo), seaweed gum (seaweed extract), starch (rice, corn, potato, wheat), and glycyrrhizic acid; microbial polymers such as xanthan gum, dextran, succinoglucan (succinoglucan), and pullulan; animal polymers such as collagen, casein, albumin, and gelatin.

Examples of the semisynthetic water-soluble polymer include starch polymers such as carboxymethyl starch and methylhydroxypropyl starch; cellulose polymers such as methyl cellulose, nitrocellulose, ethyl cellulose, methylhydroxypropyl cellulose, hydroxyethyl cellulose, sodium cellulose sulfate, hydroxypropyl cellulose, sodium carboxymethyl cellulose (CMC), crystalline cellulose, and cellulose powder; alginic acid polymers such as sodium alginate and propylene glycol alginate.

Examples of the water-soluble polymer to be synthesized include vinyl polymers such as polyvinyl alcohol, polyvinyl methyl ether, polyvinyl pyrrolidone, and carboxyvinyl polymer (carbomer); polyoxyethylene polymers such as polyethylene glycol (molecular weight 1500, 4000, 6000); a copolymer polymer such as a polyoxyethylene polyoxypropylene copolymer; acrylic polymers such as sodium polyacrylate, polyethylacrylate, polyacrylamide, and acrylic acid-alkyl methacrylate copolymer (trade name "PEMULEN TR-1"); polyethyleneimine, cationic polymers, and the like. Examples of the inorganic water-soluble polymer include bentonite, magnesium aluminum silicate (trade name "Veegum"), laponite, hectorite, and silicic anhydride.

The amount of the hydrophilic thickener (component C) incorporated in the emulsion cosmetic of the present invention is 0.01 to 3% by mass, preferably 0.05 to 3% by mass, and more preferably 0.2 to 1% by mass. When the amount is less than 0.01% by mass, a stable emulsion may not be obtained, and when the amount is more than 3% by mass, a heavy touch may be produced upon application.

The emulsion cosmetic of the present invention further contains a polyol (component D) as an essential component. By adding a polyol, the transparency and stability of the oil-in-water emulsion can be further improved. For example, by adding a polyhydric alcohol, stability can be maintained even if the amount of alcohol to be blended is reduced, and alcohol odor of the obtained preparation can be suppressed.

The polyhydric alcohol used in the present invention is not particularly limited as long as it is a polyhydric alcohol that is generally used in cosmetics, and examples thereof include glycerin for damnacard (dynamite glycerin), 1, 3-butylene glycol, dipropylene glycol, and propylene glycol. Particularly, 1, 3-butanediol is most effective for improving stability.

The amount of the polyol (component (D)) blended in the emulsion cosmetic of the present invention is 0.1 to 15 mass%, preferably 1 to 10 mass%, more preferably 3 to 7 mass%. When the amount is less than 1% by mass, a stable emulsion may not be obtained, and when the amount is more than 15% by mass, a thick touch may be produced during application.

The emulsion cosmetic of the present invention can be produced by a method which has been used for producing an emulsion. For example, the oil-in-water type emulsion cosmetic of the present invention can be obtained by mixing components forming an oil phase, and adding the oil phase, which is obtained by mixing an oil component and a polyether-modified silicone (component a) having hlb(s) (si) of 5 to 10, to an aqueous phase component containing ethanol (component B), a hydrophilic thickener (component C), and a polyol (component D), to the aqueous phase component while stirring the oil phase with a homogenizer or the like.

The oil-in-water emulsion cosmetic of the present invention is characterized by being water-moist and refreshing in use feeling during application and forming a film excellent in water resistance after application. Therefore, the emulsion cosmetic of the present invention is suitable as a base for skin care cosmetics and cosmetics.

For example, when an oil-soluble ultraviolet absorber is blended in the emulsion cosmetic of the present invention, a moist and refreshing feeling can be obtained when the emulsion cosmetic is applied to the skin, and a water-resistant coating film is formed on the skin after application, so that the UV protective power can be reliably maintained. In addition, when used as a cosmetic, the cosmetic composition can ensure good long-lasting makeup properties due to excellent water resistance.

Thus, the present invention provides an oil-in-water type cosmetic, particularly a sunscreen cosmetic, further comprising an ultraviolet absorber.

The ultraviolet absorber to be blended in the emulsion cosmetic of the present invention is not limited to oil-soluble and water-soluble ones, and is not particularly limited as long as it is an ultraviolet absorber generally used in cosmetics.

Examples thereof include methoxycinnamic acid derivatives, diphenylacrylic acid derivatives, salicylic acid derivatives, p-aminobenzoic acid derivatives, triazine derivatives, benzophenone derivatives, benzylidene malonate derivatives (benzal malonate derivative), anthranilic anhydride derivatives, imidazoline derivatives, 4-diarylbutadiene derivatives, and phenylbenzimidazole derivatives. Specific examples thereof include 2-ethylhexyl p-methoxycinnamate, Homosalate (Homosalate), octyl salicylate, hydroxybenzophenone, 4-tert-butyl-4 '-methoxydibenzoylmethane, octyltriazone, bis-ethylhexylphenol methoxyphenyl triazine, methylenebis-benzotriazolyl tetramethylbutylphenol, 2-hydroxy-4-methoxybenzophenone, dihydroxydimethoxybenzophenone, dihydroxybenzophenone, tetrahydroxybenzophenone, diethylamino-hydroxybenzoyl hexyl benzoate, 2-cyano-3, 3-diphenylacrylic acid-2' -ethylhexyl ester, silicone-15, cresolquzol polysiloxane (drometrizole polysiloxan), phenylbenzimidazole sulfonic acid, and the like. These may be used by selecting one or two or more thereof as required.

The amount of the ultraviolet absorber to be blended in the oil-in-water sunscreen cosmetic composition of the present invention is 0.1 to 35% by mass, preferably 1 to 30% by mass, and more preferably 5 to 25% by mass.

The emulsion cosmetic of the present invention may contain other components conventionally used in cosmetics, in addition to the essential components a to D and/or the ultraviolet absorber, within a range not impairing the effects of the present invention. Specifically, examples thereof include a humectant, an oil component, a buffer, a chelating agent, and a preservative.

Examples

The present invention will be described in more detail with reference to specific examples below, but the present invention is not limited to the examples below. The amount to be blended in the following examples and the like represents% by mass unless otherwise specified.

Examples 1 to 5 and comparative examples 1 to 3

An attempt was made to prepare an oil-in-water type emulsion cosmetic having the composition shown in Table 1 below. As a result, an example in which an oil-in-water type emulsion having small and stable emulsified particles was obtained was described as "o", an example in which the emulsified particles were large and stable was described as "o", an example in which the emulsified particles were large and unstable but emulsification was possible was described as "Δ", and an example in which emulsification was not possible was described as "x", and these are shown in table 1.

As is clear from Table 1, while the oil-in-water emulsions could not be prepared in comparative examples 1, 2 and 3 in which the amount of ethanol was less than 5% by mass and the acrylic acid-alkyl acrylate (C10-30) ester copolymer was not blended, the oil-in-water emulsions could be prepared in example 1 in which ethanol and the acrylic acid-alkyl acrylate (C10-30) ester copolymer were blended in an amount of 5% by mass or more, and stable oil-in-water emulsions were obtained in examples 2 to 5 in which 1, 3-butanediol was blended.

TABLE 1

*)**): trade name: BY 11-030(Dow Corning Toray Silicone Co., Ltd.): contains 50 mass% of PEG/PPG-19/19 polydimethylsiloxane and 50 mass% of cyclopentasiloxane. PEG/PPG-19/19 polydimethylsiloxane is a 55000 molecular weight polyether-modified silicone represented by the following formula:

(in the above formula, m =400, n =10, a =19, b =19)

Comparative examples 4 to 8

In the composition of example 4, an emulsification experiment was attempted with a composition in which the polyether-modified silicone having hlb (si) =64600/8387 was replaced with the various polyether-modified silicones described in table 2 and a common O/W activator. As a result, an example in which an oil-in-water type emulsion having small and stable emulsified particles was obtained was described as "o", an example in which the emulsified particles were large and stable was described as "o", an example in which the emulsified particles were large and unstable was described as "Δ", and an example in which emulsification was not possible was described as "x", and these are shown in table 2.

As a result, in comparative examples 4 to 6 using polyether-modified silicone having HLB (Si) of less than 5, oil-in-water emulsions having excellent stability could not be obtained. On the other hand, in comparative example 7 in which polyoxyethylene (20) polyoxypropylene (8) cetyl ether, which is a representative O/W active agent having hlb (si) of 10 or more, was used, an oil-in-water emulsion having excellent stability was obtained.

TABLE 2

(ultraviolet ray shielding Effect: example 4 and comparative example 7)

The ultraviolet shielding effect of example 4 and comparative example 7 were compared, and a comparative experiment for the water-resistant effect of the ultraviolet shielding effect was performed. The comparative experiment of the ultraviolet shielding effect is as follows: uniformly coating 0.75mg/cm on the PMMA (polymethyl methacrylate) plate with roughened surface²The absorbance of the preparation (example 4 or comparative example 7) was measured by a spectrophotometer (U-4100, Hitachi, Ltd.). Furthermore, comparative experiments on the water-resistant effect are as follows: after applying the preparation (example 4 or comparative example 7) to the PMMA plate described above and measuring the absorbance, the PMMA plate was exposed to a strong flowing water for 15 minutes, and after drying sufficiently, the absorbance was measured again, and the change rate of the maximum absorption wavelength of ethylhexyl methoxycinnamate was calculated.

The results are shown in FIGS. 1 and 2. Surprisingly, it is found that example 4 exhibits a higher ultraviolet shielding effect than comparative example 7 having the same absorber composition, and exhibits a very high water-resistant effect.

Example 6: sunscreen lotion

Industrial applicability

The oil-in-water emulsion cosmetic composition of the present invention can provide a feeling of use with water which is unique to an oil-in-water emulsion during application, and exhibits excellent water resistance by undergoing a phase change after application to turn into water-in-oil. Therefore, the cosmetic base can be used as a cosmetic base having both of a feeling of use and water resistance. For example, when an ultraviolet absorber is blended, reliable ultraviolet protection properties excellent in water resistance can be obtained, and the makeup retention can be improved in the finished cosmetic.

Claims (3)

1. An oil-in-water type emulsion cosmetic characterized by comprising

(A)0.1 to 10 mass% of a polyether-modified silicone having HLB (Si) of 5 to 64600/8387,

(B)8 to 50 mass% of ethanol,

(C)0.01 to 3 mass% of a hydrophilic thickener, and

(D)0.1 to 15 mass% of a polyhydric alcohol,

in the formula, m is an integer of 50 to 1000, n is an integer of 1 to 40, a is an integer of 5 to 50, and b is an integer of 5 to 50.

2. The cosmetic according to claim 1, wherein the polyether-modified silicone has a molecular weight of 50000 or more.

3. The cosmetic according to claim 1 or 2, wherein the cosmetic is used for sunscreen and further comprises 0.1 to 35% by mass of an ultraviolet absorber.