TW201628596A - Skin cosmetic, and skin care method - Google Patents

Abstract

The present invention provides a skin cosmetic which has excellent emulsion stability, can be washed out readily, can cause a large amount of an oil agent contained therein to remain on skin after being washed out and therefore can moisturize skin and can prevent skin from dryness, and has all of stability, wash-out properties and a skin care effect. A skin cosmetic comprising (A) an alkyl ether carboxylic acid and a salt thereof in an amount of 0.9 to 18.0% by weight in terms of acid contents, (B) an oil agent in an amount of 0.5 to 40.0% by weight and (C) water, wherein an organic base is contained in the component (A) as a basic substance capable of forming the salt, an alkyl ether carboxylic acid salt that is formed with the organic base makes up 24 to 100% by mole of the component (A), the ratio of the content of the component (B) to the content of the component (A), i.e., a (component (B))/(component (A)) ratio, is 0.17 to 3.81, and the ratio of the content of the component (A) to the content of the component (C), i.e., a (component (A))/(component (C)) ratio, is 0.28 or less. The present invention also provides a skin care method comprising applying the skin cosmetic according to the present invention onto skin, then massaging the skin, and then washing out the skin cosmetic from the skin.

Description

Skin cosmetics and skin care methods

The present invention relates to a skin cosmetic and skin care method.

In modern society, the pace of people's lives is accelerating. Among them, the demand for two-in-one type products having high convenience in washing and skin care is increasing.

In order to achieve this, for example, Patent Documents 1 and 2 propose to add an oil agent to a facial cleanser.

Specifically, Patent Documents 1 and 2 relate to an oil-based detergent composition in which an aqueous surfactant having a high hydrophilicity is formulated in a composition in order to achieve a cleaning effect, wherein Polyoxyethylene is used in Patent Document 1. Ammonium lauryl ether sulfate (Example 2), and C12-C14 alkyl glyceryl ether sulfonate sodium is used in Patent Document 2, but if such a detergent composition does not use a stabilizer, it cannot be emulsified stably.

Further, Patent Documents 1 and 2 provide a skin care effect by adding an oil agent and leaving the oil agent on the skin after washing, but the affinity of the emulsion formed of a highly hydrophilic surfactant to the skin is further improved. Poor, so the oil is difficult to stay on the skin.

(Patent Document 1) Chinese Patent No. 1181006A

(Patent Document 2) Chinese Patent No. 1169112A

The present invention provides a skin cosmetic comprising the following components (A) to (C): (A) an alkyl ether carboxylic acid and a salt thereof in an amount of from 0.9 to 18.0% by weight in terms of an acid; (B) an oil agent 0.5 to 40.0% by weight; (C) water; and the component (A) contains an organic base in the basic substance forming the above salt, and the alkyl ether carboxylate formed from the organic base in the component (A) It accounts for 24 to 100 mol%, the component (B)/component (A) is 0.17 to 3.81, and the component (A)/component (C) is 0.28 or less.

Further, the present invention provides a skin care method which applies the skin cosmetic of the present invention to the skin and washes it.

Figure 1 is a graph showing the linear relationship between the amount of oil orange SS and the a ^* value.

An object of the present invention is to provide an emulsion having excellent emulsion stability, easy to clean, and a residual amount of the oil agent contained on the skin after being washed, so that the skin is moist and not dry, and has both stability, cleansing and skin maintenance effects. Skin cosmetics.

The present inventors have found that a predetermined alkyl ether carboxylic acid is used as a raw material in an oil/water (O/W, Oil/Water) system to which an oil agent is added, and a part or all of it is utilized as an organic base. The alkaline substance is neutralized to form an alkyl ether carboxylate, whereby excellent emulsion stability can be obtained, and the oil agent contained in the skin is washed on the skin. The amount of residue on the skin is improved to make the skin moist and difficult to dry, and has both stability, cleansing and skin care effects.

Hereinafter, the components of the skin cosmetic of the present invention will be described in detail.

<ingredient (A)>

The alkyl ether carboxylic acid and the salt thereof as the component (A) used in the present invention are obtained by neutralizing an alkyl ether carboxylic acid with a basic substance. After neutralization by a basic substance, a part or all of the alkyl ether carboxylic acid becomes an alkyl ether carboxylate depending on the concentration of the basic substance to be used. Hereinafter, "alkyl ether carboxylic acid", "basic substance", and "alkyl ether carboxylic acid and its salt" will be specifically described.

(alkyl ether carboxylic acid)

The alkyl ether carboxylic acid is represented by the following formula (I).

RO-(CH ₂ CH ₂ O) _n CH ₂ -COOH (I)

(wherein R represents an alkyl group having 10 to 18 carbon atoms, and n represents an average of 0.5 to 10)

In terms of stability and cleanability of the skin cosmetic, R is preferably an alkyl group having 12 to 16 carbon atoms or a mixture thereof, more preferably an alkyl group having 12 to 14 carbon atoms or the like. mixture. Further, the average addition molar number of ethylene oxide is preferably from 1 to 8, further from 2 to 6, and further from 2 to 4.

One or two or more kinds of the alkyl ether carboxylic acids can be used. Since the alkyl ether carboxylic acid has low solubility and is not excellent in cleanability, it is necessary to neutralize with an alkali to improve the cleaning power when it is used. In the case of neutralization of an alkyl ether carboxylic acid, an alkali metal such as potassium hydroxide or sodium hydroxide is usually used as the base, but the hydrophilicity of the salt formed by the above is higher. High, it is difficult to emulsify the oil agent, and it is easy to cause phase separation. Further, it is difficult for the alkyl ether carboxylic acid to increase the residual amount of the oil agent on the skin in the preparation. Therefore, in order to form a stable oil-based emulsion cosmetic in water, it is necessary to neutralize all or a part of the alkyl ether carboxylic acid with a basic substance containing an organic base to form an alkyl ether carboxylate. Thereby, the cleanability can be ensured and an emulsified cosmetic which is stable against phase separation can be formed. Further, the amount of the oil agent contained in the emulsified cosmetic after washing on the skin (also referred to as "residual oil amount") can be improved.

(alkaline substance)

The basic substance used for neutralizing the alkyl ether carboxylic acid to form a salt contains an organic base and optionally contains an inorganic base.

Examples of the organic base include diethylaminoethanol, methylaminoethanol, aminomethylpropanol, dimethylaminoethanol, isopropylamine, triethanolamine, and isopropyldimethylamine. Ethylethanolamine, an alkanolamine, a mixture thereof, and the like, and, for example, L-arginine, alanine, glycine, serine, lysine, glutamic acid, a basic amino acid, and the like a mixture or the like. Among them, one or two or more selected from the group consisting of aminomethylpropanol, triethanolamine, and L-arginine are preferred.

Examples of the inorganic base include potassium hydroxide, sodium hydroxide, and a mixture thereof.

As a composition of the basic substance in the component (A), the organic base is an essential component and may also contain an inorganic base. Regarding the degree of neutralization of the alkyl ether carboxylic acid as a raw material (i.e., the molar ratio of the organic base to the alkyl ether carboxylic acid as a raw material), the stability of the skin cosmetic, and the skin after washing The oil contained in the cosmetic is 0.24 to 1.00 in terms of the amount of residual oil on the skin.

Further, in the case where the basic substance in the component (A) also contains an inorganic alkali, the stability of the skin cosmetic and the residual oil amount of the oil agent contained in the skin cosmetic after washing on the skin are In terms of the inorganic base, the degree of neutralization of the alkyl ether carboxylic acid as a raw material (that is, the molar ratio of the inorganic base to the alkyl ether carboxylic acid as a raw material) is 0 to 0.3, preferably 0 to 0.1. Further preferably, it is not included. Further, it is preferred that the inorganic salt formed of the inorganic base is 30 mol% or less in the component (A). On the other hand, the proportion of the organic base in the alkaline substance is preferably an alkyl ether carboxylic acid which is not salt formed by neutralizing the alkyl ether carboxylic acid as a raw material by using a basic substance, and an organic base is used. The total of the alkyl ether carboxylates obtained by the sum is 70 to 100 mol% of the component (A).

(alkyl ether carboxylic acid and its salt)

After neutralizing the alkyl ether carboxylic acid as a raw material with a basic substance, an alkyl ether carboxylic acid and a salt thereof, that is, the component (A) of the present invention can be obtained. The composition of the component (A) differs depending on the type and amount of the alkaline substance used for neutralization, but includes the following three. After the neutralization, the salt is not formed in the above-mentioned alkyl ether carboxylic acid as a raw material, and is represented by the following general formula (I'); the alkyl ether carboxylate obtained by neutralization with an organic base, and The formula (II) represents an alkyl ether carboxylate obtained by neutralizing with an inorganic base which can be optionally contained, and is represented by the following formula (III).

RO-(CH ₂ CH ₂ O) _n CH ₂ -COOH (I')

RO-(CH ₂ CH ₂ O) _n CH ₂ -COOX (II)

RO-(CH ₂ CH ₂ O) _n CH ₂ -COOX' (III)

(wherein R and n are exactly the same as defined in the above formula (I), X represents a cation derived from an organic base, and X' represents a cation derived from an inorganic base).

Further, as X, for example, it is derived from diethylaminoethanol, A a cation of an alkanolamine such as alkinoethanol, aminomethylpropanol, dimethylaminoethanol, isopropylamine, triethanolamine, isopropyldimethylamine, ethylethanolamine; and, for example, derived from L - a cation of a basic amino acid such as arginine, alanine, glycine, serine, lysine or glutamic acid. Among them, X is preferably a cation derived from aminomethylpropanol, triethanolamine, and L-arginine.

Examples of X' include alkali metal ions such as sodium and potassium.

The alkyl ether carboxylic acid and its salt include the following (1) to (4) depending on factors such as the degree of neutralization of the alkyl ether carboxylic acid as a raw material and the ratio of the organic base to the basic substance. Any of the four forms.

(1) a mixture of an alkyl ether carboxylic acid represented by the above formula (I') and an alkyl ether carboxylate represented by the above formula (II)

(2) a mixture of an alkyl ether carboxylic acid represented by the above formula (I'), an alkyl ether carboxylate represented by the above formula (II), and an alkyl ether carboxylate represented by the above formula (III)

(3) an alkyl ether carboxylate represented by the above formula (II)

(4) a mixture of an alkyl ether carboxylate represented by the above formula (II) and an alkyl ether carboxylate represented by the above formula (III)

The degree of neutralization of the alkyl ether to the alkyl ether carboxylic acid is 0.24 to 1, in terms of the stability of the skin cosmetic and the amount of oil remaining on the skin of the oil agent contained in the skin cosmetic after washing. The component (A) may be any one of the above (1) to (4). Therefore, in the component (A), the alkyl ether carboxylate (that is, the alkyl ether carboxylate represented by the above formula (II)) obtained by neutralization with an organic base accounts for 24 to 100 mol%.

Further, in the component (A), an alkyl ether carboxylic acid having no salt (that is, an alkyl ether carboxylic acid represented by the above formula (I')) and an alkyl ether carboxylic acid obtained by neutralizing with an organic base are used. The salt (that is, the alkyl ether carboxylate represented by the above formula (II)) accounts for 70 to 100 moles ear%.

From the viewpoint of the stability of the skin cosmetic and the cleaning effect, in the skin cosmetic of the present invention, the content of the component (A) is calculated in terms of acid (that is, based on calculation as an alkyl ether carboxylic acid as a raw material). It is 0.9% by weight or more, preferably 1.8% by weight or more, and the content of the component (A) is 18.0% by weight or less. When these aspects are summarized, the content of the component (A) in the skin cosmetic of the present invention is 0.9 to 18.0% by weight, preferably 1.8 to 18.0% by weight.

<ingredient (B)>

As the oil agent of the component (B) used in the present invention, a polar oil is used, and specific examples thereof include sunflower oil, castor oil, cottonseed oil, peanut oil, corn oil, rice bran oil, rice germ oil, and olive oil. , almond oil, palm oil, sesame oil, evening primrose oil, safflower oil, avocado oil, coconut oil, jojoba oil and other vegetable oils or derivatives thereof; glycerides such as lanolin and its derivatives; such as caprylic acid / citric acid Other fatty acid glycerides such as glycerides, myristic acid/glyceryl stearate; for example, isopropyl myristate, isopropyl palmitate, isooctyl palmitate, 2-ethylhexyl stearate, stearic acid An ester of an alcohol and a fatty acid, such as butyl acrylate, myristyl myristate, isopropanolate, or bis(phthalic acid) 2,2-dimethyl-1,3-propane diester.

One type or two or more types of ingredients (B) can be used. In the skin cosmetic of the present invention, the component (B) is preferably selected from the group consisting of fatty acids in terms of providing a good skin care effect and enhancing the affinity of the oil to the skin to obtain a more excellent skin softening effect. One or more selected from the group consisting of a glyceride and an ester of an alcohol and a fatty acid, more preferably a fatty acid glyceride having an alkyl chain having 10 or less carbon atoms, and an alkyl group having 10 or less carbon atoms One or two of the esters formed by alcohols and fatty acids More preferably, one or more selected from the group consisting of octanoic acid/capric glyceride, bis(capric acid) 2,2-dimethyl-1,3-propane diester and isopropyl citrate .

The skin makeup of the present invention is in terms of the stability of the skin cosmetic, and the amount of oil remaining on the skin of the oil agent contained in the skin cosmetic after being applied to the skin and being rinsed with water. The content of the component (B) is 0.5% by weight or more, preferably 1.5% by weight or more, and the content of the component (B) is 40.0% by weight or less, preferably 30.0% by weight or less. When these aspects are summarized, the content of the component (B) in the skin cosmetic of the present invention is 0.5 to 40.0% by weight, preferably 1.5 to 30.0% by weight.

<ingredient (C)>

Examples of the component (C) water used in the present invention include deionized water, distilled water, high-purity water, and ultra-high-purity water.

In the skin cosmetic of the present invention, the content of the component (C) is the residual amount (the total amount is 100% by weight) after removing the components (A) to (B) and the following components.

Further, in terms of the stability of the skin cosmetic, and the amount of oil remaining on the skin of the oil-containing agent contained in the skin cosmetic after being applied to the skin and being washed with water, the component (B) The content ratio to the component (A) (component (B) / component (A)) is from 0.17 to 3.81, preferably from 0.67 to 2.22. Further, the content ratio of the component (A) to the component (C) (component (A) / component (C)) is 0.28 or less.

<Other ingredients>

Further, the skin cosmetic of the present invention may contain, in addition to the above components, a component which is usually used for a skin cosmetic, as long as it does not affect the effects of the present invention. For example: surfactants other than the component (A), moisturizers, whitening agents, blood circulation promoters, anti-inflammatory agents, fungicides, ultraviolet absorbers, colorants, preservatives, antioxidants, fragrances, pH adjusters, chelating agents Wait.

Examples of the surfactant other than the component (A) include alkyl sulfates such as polyoxyethylene lauryl ether sulfate and polyoxyethylene lauryl ether ammonium sulfate; fatty acids such as lauric acid, myristic acid, and palmitic acid; Glycosides and the like. The surfactant other than the component (A) accounts for 50% by weight of the composition in terms of the stability of the skin cosmetic and the amount of oil remaining on the skin of the oil agent contained in the skin cosmetic after washing. The amount is preferably 25% by weight or less, more preferably 10% by weight or less, still more preferably 1% by weight or less, still more preferably 0.1% by weight or less, and most preferably substantially no.

The skin cosmetic of the present invention is prepared by the following method, thereby forming an oily emulsion cosmetic in water.

The alkyl ether carboxylic acid as a raw material is mixed with the component (B) to form an oil phase. The oil phase may be heated to 50 ° C or higher, preferably 70 ° C to 100 ° C, depending on the case. The alkaline substance is mixed with the component (C) to form an aqueous phase. The aqueous phase may be heated to 50 ° C or higher, preferably 70 ° C to 100 ° C, depending on the case. Then, the oil phase is added to the aqueous phase while stirring, and the alkyl ether carboxylic acid as a raw material is neutralized with a basic substance to obtain a component (A), and further, the system is emulsified to form an oily cosmetic in water. . When the oil phase, the water phase, or both are heated, the emulsified cosmetic is cooled to 10 ° C to less than 50 ° C.

The skin cosmetic of the present invention has a pH of at least 4.3 at 25 ° C, preferably 5.18 or more, and a pH of 7.52 or less, preferably 7.1 or less. When these aspects are summarized, the pH of the skin cosmetic of the present invention is 4.3 to 7.52, preferably 5.18 to 7.1.

The skin cosmetic of the present invention can be used as a skin cosmetic such as a facial cleanser, a body wash, and a facial mask. The skin cosmetic of the present invention is excellent in emulsion stability. When the skin cosmetic of the present invention is used as a facial cleanser, it is easy to wash, and after washing, the amount of residual oil on the skin of the oil agent contained in the skin cosmetic is improved to make the skin moist. Do not dry, you can get good skin care. The skin cosmetic of the present invention can be used by being applied to the skin, preferably in addition to the scalp, and more preferably applied to any of the body parts of the face, body, hands and feet.

<Skin care method>

By applying the skin cosmetic of the present invention to the skin, massage and washing, the skin is removed, and the oil component is moderately retained, whereby skin care can be achieved. Further, at the time of use, the skin cosmetic of the present invention can be directly used by hand, and it can also be used by using a tool such as a sponge. Further, the present invention provides a washing method which applies the skin cosmetic of the present invention to the skin, and the residual amount of the oil agent contained on the skin after washing is improved, so that the skin is moist and difficult to dry. Further, there is provided a method of applying the skin cosmetic of the present invention to the skin to impart moisture to the skin.

Preferred embodiments of the present invention are further disclosed below with respect to the above embodiments.

<1> A skin cosmetic comprising the following components (A) to (C): (A) an alkyl ether carboxylic acid and a salt thereof in an amount of 0.9 to 18.0% by weight in terms of an acid; (B) an oil agent 0.5 ~40.0% by weight; (C) water; The component (A) contains an organic base in the basic substance forming the above salt, and in the component (A), the alkyl ether carboxylate formed from the organic base accounts for 24 to 100 mol%, and the component (B)/ The component (A) is 0.17 to 3.81, and the component (A)/component (C) is 0.28 or less.

(2) The skin cosmetic according to the above-mentioned item, wherein the alkyl ether carboxylic acid obtained by neutralizing the inorganic substance in the basic substance forming the salt and neutralizing with the inorganic base in the component (A) The salt is 30 mol% or less.

<3> The skin cosmetic according to <1> or <2>, wherein the alkyl group of the alkyl ether carboxylic acid has a carbon number of 10 to 18, preferably 12 to 16, more preferably 12 to 14.

The skin cosmetic according to any one of <1> to <3> wherein the organic base is selected from the group consisting of diethylaminoethanol, methylaminoethanol, aminomethylpropanol, and 2- Methylaminoethanol, isopropylamine, triethanolamine, isopropyldimethylamine, ethylethanolamine, L-arginine, alanine, glycine, serine, lysine, glutamic acid One or two or more kinds thereof are preferably one or more selected from the group consisting of aminomethylpropanol, triethanolamine, and L-arginine.

The skin cosmetic according to any one of <1> to <4> wherein the content of the component (A) is from 1.8 to 18.0% by weight.

The skin cosmetic according to any one of <1> to <5> wherein the component (B) is a polar oil, preferably a fatty acid selected from the group consisting of an alkyl chain having 10 or less carbon atoms. One or more of an oil ester and an ester of an alcohol and a fatty acid having an alkyl chain having 10 or less carbon atoms, more preferably selected from octanoic acid/capric acid glyceride and isopropyl citrate One or two or more kinds of esters.

The skin cosmetic according to any one of <1> to <6> wherein the content of the component (B) is from 1.5 to 30.0% by weight.

The skin cosmetic according to any one of <1> to <7> wherein the component (B)/component (A) is 0.67 to 2.22.

<9> The skin cosmetic according to any one of <1> to <8> wherein the pH at 25 ° C is 4.3 to 7.52, preferably 5.18 to 7.1.

<10> A skin care method according to any one of <1> to <9>, which is applied to the skin, massaged and washed.

<11> A method of applying the skin cosmetic according to any one of <1> to <9> to the skin and washing the skin.

<12> A skin cosmetic according to any one of <1> to <9>, which is applied to the skin to impart moisture to the skin.

The method for producing a skin cosmetic according to any one of <1> to <9>, which comprises the step of mixing an alkyl ether carboxylic acid as a raw material with a component (B). An oil phase is formed, and the alkaline substance is mixed with the component (C) to form an aqueous phase, and thereafter, the oil phase is added to the aqueous phase to make the alkyl ether carboxylic acid as a raw material alkaline. The substance is neutralized to obtain the component (A), and further, the system is emulsified to form an oily cosmetic in water.

The method for producing a skin cosmetic according to any one of <1> to <9>, comprising the steps of: Mixing the alkyl ether carboxylic acid as a raw material with the component (B) to form an oil phase, and mixing the basic substance with the component (C) to form an aqueous phase; The oil phase is added to the aqueous phase obtained in the above step, and the alkyl ether carboxylic acid as a raw material is neutralized with a basic substance to obtain the component (A); The mixture of the aqueous phase and the oil phase obtained in the above step was emulsified.

[Examples]

Hereinafter, the present invention will be described in further detail by way of examples and comparative examples. However, the invention is not limited to the following embodiments. Further, the amount of each component is % by weight.

[Examples 1 to 32, Comparative Examples 1 to 26]

The skin cosmetic of the composition shown in Tables 1 to 8 was prepared by the following preparation method, and the stability of the skin cosmetic was based on the following evaluation criteria (the stability immediately after preparation, and after standing for 3 months at room temperature) Stability) and the amount of residual oil on the skin of the oil agent contained in the skin cosmetic after washing. The results are shown together in Tables 1-8.

<Preparation method>

The alkyl ether carboxylic acid as a raw material and the component (B) were added to a beaker at a temperature of 75 ° C, and stirred at a number of revolutions of 200 rpm until uniformly mixed to form an oil phase A. The alkaline substance and the component (C) are added to the beaker at a temperature of 75 ° C to 200 The number of revolutions of rpm was stirred until homogeneously mixed to form aqueous phase B. Then, the oil phase A is added to the aqueous phase B, and the alkyl ether carboxylic acid as a raw material is neutralized with a basic substance to obtain the component (A) while stirring at a number of revolutions of 200 rpm for 20 minutes. The system was placed in an ice water bath and cooled to 35 ° C, and stirring was stopped to form an oily cosmetic in water.

<Measurement of pH>

100 mL of the obtained skin cosmetic was added to a beaker, and the temperature was adjusted to 25 ° C using a 25 ° C thermostatic chamber. The pH measurement electrode was immersed in a sample adjusted to a constant temperature for 3 minutes, and the pH was measured. The pH meter was manufactured using pH METER HM-3OG, DKK‧TOA CORPORATION.

<Evaluation criteria> 1. The stability of skin cosmetics (1) Stability (just after preparation)

The skin cosmetic immediately after preparation was visually observed and evaluated according to the following criteria.

AA: Very uniform and without delamination.

AA~BB: There is basically no stratification.

BB: There are layers.

CC: Thoroughly layered into a solid.

(2) Stability (after 3 months at room temperature)

The skin cosmetic was allowed to stand at room temperature for 3 months, and then visually observed and evaluated according to the following criteria.

AA: Very uniform and without delamination.

AA~BB: There is basically no stratification.

BB: There are layers.

CC: Thoroughly layered into a solid.

2. The amount of oil remaining on the skin of the oil contained in the skin cosmetic after washing (1) <Preparation of sample for measurement>

A skin cosmetic was prepared in the same manner as in the Example except that the oil orange SS of 0.5% of the content of the component (B) was added to the component (B), and a sample for measurement described later was prepared. Furthermore, the overall amount is adjusted by water to make it 100%.

(2) <Measurement equipment and materials>

Chromatic aberration meter: Spectrophotometer CM-2500D, manufactured by KONIC MINOLTA SENSING, INC

Artificial skin: Polyurethane, milky white, manufactured by OKAMOTO KASEIHIN CO., LTD

(3) Measuring method

a ^* is a red value measured by a chromatic aberration meter, and the red value of the sample for measurement before and after the measurement is represented by a ^*0 and a ^*1 , respectively. Oil Orange SS is a dye that is only dissolved in oil and is used to display the amount of residual oil in the measurement of the present invention. 3 x 5 cm of untreated artificial skin was taken, and the a ^* value was measured by a chromatic aberration meter and expressed by a ^*0 . Then, 50 mg of water was added dropwise to the artificial skin and uniformly spread to form a water film. A 50 mg sample of the skin cosmetic was added dropwise to the water film, and massaged for 30 seconds, followed by rinsing with water for 10 seconds, and gently rubbing with a wim paper (kimtowel) to wipe off the water, and measuring with a chromatic aberration meter a ^* Value is expressed as a ^{* 1} . The amount of oil remaining on the skin of the oil agent contained after the skin cosmetic was applied to the skin and washed was determined by the following formula.

Residual oil = oil orange SS amount / 0.5% = (a ^{* 1} - a ^{* 0} ) / 4.6248 / 0.5%

(a ^* indicates chromaticity, and it is based on the L ^* a ^* b ^* color system standardized by the International Commission on Illumination (CIE) in 1976 and standardized by JIS Z 8729)

Further, the amount of residual oil was determined by preparing a calibration curve as follows. First, three 3×5 cm untreated artificial skins were taken, and the oil orange SS was uniformly applied so as to be 0.5 μg/cm ² , 1 μg/cm ² , and 2 μg/cm ² , respectively. After drying, the a ^* value was measured using a chromatic aberration meter. As shown in Fig. 1, the amount of oil orange SS indicates a linear relationship with the a ^* value. Specifically, the amount of oil orange SS = a ^* value / 4.6248.

It is apparent from Table 1 that the skin cosmetic of the comparative example is used as a raw material because the predetermined alkyl ether carboxylic acid of the present invention is not used as a raw material, or a basic substance containing an organic base as in the present invention is not used. The ether ether carboxylic acid was neutralized, and therefore, each of the items in terms of stability (just after preparation) and residual oil amount was inferior to the examples.

As is clear from Table 2, the skin cosmetic of the comparative example contains not only the organic base as in the present invention because of the alkaline substance used, but each of the items related to the stability (just after preparation) and the amount of residual oil. The terms are all worse than the examples.

As is clear from Table 3, the skin cosmetic of the comparative example is outside the range of the present invention because the organic base has a degree of neutralization of the alkyl ether carboxylic acid as a raw material, that is, the organic base is changed relative to the alkyl ether carboxylic acid as a raw material. Excessively, each of the items related to stability (just after preparation) and residual oil amount is inferior to the examples.

It is clear from Table 4 that the proportion of the skin cosmetic of the comparative example in the alkaline substance used is not 30 mol% of the inorganic salt formed by the inorganic base as in the present application as the component (A). In the following cases, each of the items related to stability (just after preparation) and residual oil amount was inferior to the examples.

It is clear from Table 5 that the skin cosmetic of the comparative example is used as the component (B) because it is not used as the component (B), so it is stable (just after preparation) and stable (placed at room temperature for 3 months). Each of the related items is later than the embodiment.

As is clear from Tables 6 and 7, in the skin cosmetic of the examples, excellent stability (just after preparation), stability (after standing at room temperature for 3 months), and residual oil amount were obtained. Therefore, according to the present invention, it is possible to provide an emulsion having excellent emulsion stability, easy to clean, and the residual amount of the oil agent on the skin is improved to make the skin moist and difficult to dry, and which has both stability, cleansing and skin maintenance effects. Skin cosmetics.

It is clear from Table 8 that the skin cosmetic of the comparative example is outside the scope of the present invention because B/A and/or A/C are outside, and therefore, in all items related to stability (just after preparation) and residual oil amount, One is worse than the example.

[Comparative Example 27]

The skin cosmetic of Comparative Example 27 utilized the same composition as that of Example 1, and was prepared as follows. Ingredient (B) (octanoic acid/triglyceride) was added to the beaker at 75 ° C to form an oil phase A'. The alkyl ether carboxylic acid (polyoxyethylene (6) lauryl ether carboxylic acid), the basic substance (triethanolamine), and the component (C) (water) as raw materials are added to the beaker at a temperature of 75 ° C. The mixture was rotated at a number of revolutions of 200 rpm, and the alkyl ether carboxylic acid as a raw material was neutralized with a basic substance to obtain a component (A), and at the same time, a transparent aqueous phase B' was formed. Then, the above oil phase A' was added to the aqueous phase B' and rotated at a number of revolutions of 200 rpm for 20 minutes to form an oily cosmetic in water. The water-oil type cosmetic prepared in the preparation was evaluated for its stability (immediately after preparation), and it was found to be "CC (layering)".

As is clear from this, the skin cosmetic of Comparative Example 27 was inferior to Example 1 in the evaluation of stability (just after preparation) because the production method of the present invention was not used.

(Note) The components in Tables 1 to 8 are the following.

* 1: AKYP RLM 45 CA (90%), manufactured by Kao Chemicals GmbH.

* 2: AKYP LM 26-C (86%) manufactured by Kao Chemicals GmbH.

* 3: COCONAD MT, manufactured by Kao Corporation.

* 4: EMAL 270S, manufactured by Kao Chemicals Shanghai.

* 5: EMAL 170S-A, manufactured by Kao Chemicals Shanghai.

* 6: PALMAC 98-12, manufactured by ACIDCHEM INTERNATIONAL SDN.BHD.

* 7: PALMAC 98-14, manufactured by ACIDCHEM INTERNATIONAL SDN.BHD.

* 8: PALMAC 98-16, ACIDCHEM INTERNATIONAL SDN. BHD. Manufacturing.

* 9: AG-10LK, manufactured by Kao Corporation.

* 10: HYBRIRD SUNFLOWER SEED OIL, manufactured by YOKOZEKI OIK & FAT INDUSTRY CO., LTD, with an active ingredient content of 100%.

* 11: EXCEPARL IPP, manufactured by Kao Corporation, with an active ingredient content of 100%.

* 12: ESTEMOL N-01 The Nisshin Oillio Group. Inc. manufactured with an active ingredient content of 100%.

* 13: EXCEPARL SS, manufactured by Kao Corporation, with an active ingredient content of 100%.

* 14: Manufactured by HICALL K-350, KANEDA CO., Ltd., the active ingredient content is 100%.

* 15: SILICONE SH 245 FLUID, manufactured by Dow Corning Toray Company, Limited, with an active ingredient content of 100%.

Claims (8)

A skin cosmetic comprising the following components (A) to (C): (A) an alkyl ether carboxylic acid and a salt thereof, in an amount of from 0.9 to 18.0% by weight in terms of acid; (B) an oil agent of 0.5 to 40.0 (C) water; component (A) contains an organic base in the basic substance forming the above salt, and in the component (A), the alkyl ether carboxylate formed from the organic base accounts for 24 to 100. The molar %, the component (B) / the component (A) is 0.17 to 3.81, and the component (A) / component (C) is 0.28 or less. The skin cosmetic of claim 1, wherein the basic substance forming the salt contains an inorganic base, and in the component (A), the alkyl ether carboxylate formed of the inorganic base is 30 mol% or less. . The skin cosmetic of claim 1, wherein the alkyl group of the alkyl ether carboxylic acid has a carbon number of 10 to 18. The skin cosmetic of claim 1, wherein the organic base is one or more selected from the group consisting of aminomethylpropanol, triethanolamine, and L-arginine. The skin cosmetic of claim 1, wherein the oil of the component (B) is a polar oil. The skin cosmetic according to claim 5, wherein the oil agent of the component (B) is a fatty acid glyceride having an alkyl chain having 10 or less carbon atoms. A method for producing a skin cosmetic according to any one of claims 1 to 6, comprising the steps of: mixing an alkyl ether carboxylic acid as a raw material with a component (B) to form an oil phase, and The component (C) is mixed to form an aqueous phase, and thereafter, the oil phase is added to the aqueous phase, and the alkyl ether carboxylic acid as a raw material is neutralized with a basic substance to obtain the component (A). Further, the system is emulsified to form an oily type cosmetic in water. A skin care method which applies the skin cosmetic of any one of claims 1 to 6 to the skin, massages and washes.