JP2005179320A - Oil-in-water emulsion composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an emulsified composition having excellent moisture retention, suppressing crystal precipitation of ceramide and ceramide-like compounds, and having good storage stability.
The following components (A) to (E):
(A) one or more compounds selected from ceramide and ceramide-like compounds,
(B) a polymer of acrylic acid and / or methacrylic acid having an alkyl group in the side chain,
(C) paraoxybenzoic acid ester or phenoxyethanol,
(D) Oil-in-water type containing surfactant (E) water of HLB 8 or less and having a mass ratio of components (A) and (C) of (A) / (C) = 40/1 to 1/10 Emulsified composition.
[Selection figure] None

Description

  The present invention relates to an oil-in-water emulsion composition that is excellent in moisture retention, suppresses crystal precipitation of ceramide and a ceramide-like compound, and has good emulsion stability.

  It is known that ceramide, which is a main component of intercellular lipids present in the skin stratum corneum, is a biological substance that plays a role of skin barrier and moisture. However, ceramide has a drawback that it has high crystallinity and poor compatibility with general cosmetic raw materials. Therefore, studies for stably blending ceramide into cosmetics are being conducted.

  For example, Patent Document 1 relates to a skin external preparation containing two surfactants (nonionic surfactant, ionic surfactant) and other oil agent in ceramide, by adjusting the weight ratio thereof, It is disclosed that a stable composition is obtained. However, when the total amount of the surfactant in the composition is large, the storage stability of the cosmetic tends to be deteriorated, which causes stickiness.

Patent Document 2 relates to an emulsified composition in which an oil component, a copolymer of acrylic acid and alkyl methacrylate is combined with at least one selected from galactosylceramide and glucosylceramide, which are ceramide-like substances, as a surfactant. Furthermore, cosmetics that have good emulsification stability and improve the skin such as dry skin and atopic dermatitis are disclosed. However, in the case of cosmetics, there is a problem that crystals of ceramide and ceramide-like compounds (ceramides) are precipitated when paraoxybenzoic acid ester (paraben) or phenoxyethanol, which is widely used as an antiseptic, is added. .
JP-A-6-345633 JP 2000-264825 A

  An object of the present invention is to provide an oil-in-water emulsion composition that has excellent moisture retention, suppresses crystal precipitation of ceramide and a ceramide-like compound, and has good emulsion stability.

  The inventors contain preservatives such as ceramides and parabens in a mass ratio of ceramides / preservatives = 40/1 to 1/10, and are obtained by emulsification with an alkyl-substituted acrylic acid copolymer. It has been found that by adding a small amount of a specific surfactant to the oil-type emulsion composition, precipitation of fine crystals such as ceramides is suppressed, and an emulsion composition having excellent stability can be obtained.

That is, the present invention includes the following components (A) to (E):
(A) one or more compounds selected from ceramide and ceramide-like compounds,
(B) a polymer of alkyl acrylate and / or alkyl methacrylate,
(C) paraoxybenzoic acid ester or phenoxyethanol,
(D) Oil-in-water type containing surfactant (E) water of HLB 8 or less and having a mass ratio of components (A) and (C) of (A) / (C) = 40/1 to 1/10 An emulsified composition is provided.

  The oil-in-water emulsion composition of the present invention has excellent moisture retention, suppresses crystal precipitation of ceramide and a ceramide-like compound, and has good storage stability.

The ceramide and ceramide-like compound of component (A) used in the present invention are components that give excellent moisture retention.
Ceramides include those extracted and purified from animals and plants, and those synthesized by microbiological methods or scientific methods. Examples thereof include amide derivatives represented by the following general formula (1).

(In the formula, R ¹ is a linear or branched saturated or unsaturated hydrocarbon group having 8 to 50 carbon atoms which may be substituted by one or more hydroxyl groups, or R ³ —COO—R ⁴ — ( R ³ is a linear or branched saturated or unsaturated hydrocarbon group having 8 to 30 carbon atoms, and R ⁴ is a linear or branched chain having 8 to 40 carbon atoms which may be substituted by one or more hydroxyl groups. A saturated or unsaturated divalent hydrocarbon group), and R ² represents a linear or branched saturated or unsaturated group having 8 to 50 carbon atoms which may be substituted by one or more hydroxyl groups. Represents a saturated hydrocarbon group)

Specifically, the type I described in Robson KJ et al., J. Lipid Res., 35, 2060 (1994), Wertz PW et al., J. Lipid Res., 24, 759 (1983), etc. Ceramide of VII is included.
As a commercially available ceramide, use ceramide III, ceramide IIIB, ceramide IIIA, ceramide IV, phytoceramide I (degussa), ceramide II (Cederama), ceramide TIC-001 (Takasago Inc.), etc. Can do.

  On the other hand, examples of the ceramide-like compound include amide derivatives represented by the following general formula (2) described in JP-A-62-228048.

(In the formula, R ⁵ represents a linear or branched saturated or unsaturated hydrocarbon group having 9 to 25 carbon atoms, and R ⁶ represents a saturated or unsaturated linear or branched chain having 10 to 26 carbon atoms. (Indicates hydrocarbon group)

  The amide derivative represented by the general formula (2) can be produced by a method described in JP-A-62-228048, JP-A-62-228048, or the like. Specifically, there are N- (hexadecyloxyhydroxypropyl) -N-hydroxyethylhexadecanamide, and commercially available products such as Sofcare Ceramide SL-E (Kao Corporation) can be used.

  One or more types of component (A) can be used, preferably 0.01 to 10% by mass in the total composition, and 0.1 to 10% by mass from the viewpoint of moisturizing effect. Further preferred.

  The oil-in-water emulsion composition of the present invention can contain an oily component that is usually used in cosmetics in addition to the component (A). Such components include liquid, semi-solid and solid, synthetic and natural oil components such as hydrocarbon oils, ester oils, ether oils, silicone oils, fluorine oils and the like.

  Examples of liquid oils include vegetable oils such as jojoba oil and olive oil; animal oils such as liquid lanolin; hydrocarbon oils such as liquid paraffin and squalane; ester oils such as fatty acid esters, polyhydric alcohol fatty acid esters, glycerin derivatives, and amino acid derivatives; Examples include silicone oils such as dimethylpolysiloxane, dimethylcyclopolysiloxane, methylphenylpolysiloxane, methylhydrogenpolysiloxane, and higher alcohol-modified organopolysiloxane; fluorine oils such as fluoropolyether and perfluoroalkylethersilicone.

Examples of solid or semi-solid oil components include vegetable oils such as jojoba wax; alkyl glyceryl ethers such as glycerin monostearyl ether and glycerin monocetyl ether; higher alcohols such as cetanol, stearyl alcohol, and behenyl alcohol.
As oil-soluble active ingredients, for example, oil-soluble vitamins such as β-carotene, DL-α-tocopherol acetate, DL-α-tocopherol, vitamin A oil and the like can be blended.

  The total content of the oil phase component in the oil-in-water emulsion composition is preferably 30% by mass or less, and preferably 0.1 to 30% by mass in the total composition from the aspects of moisture retention and feeling of use (stickiness). Is more preferable, and further 0.5 to 20% by mass, particularly 1 to 10% by mass is preferable. Furthermore, it is preferable that a component (A) is 50 mass% or less in an oil phase, and also 10-30 mass%.

Component (B) used in the present invention is a polymer of alkyl acrylate and / or alkyl methacrylate. Here, the alkyl group is preferably a linear or branched group having 10 to 30 carbon atoms.
Such a polymer may be one containing at least one monomer of alkyl (meth) acrylate, such as (meth) alkyl acrylate polymer; (meth) acrylic acid / (meth) alkyl acrylate copolymer. Is mentioned. In addition, the component (B) may contain other monomers as long as it sufficiently functions as an emulsifier for the composition. Examples of such a copolymer include a copolymer of at least one monomer of alkyl acrylate and / or alkyl methacrylate and polyoxyethylene alkyl ether. In the present specification, (meth) acryl represents acrylic and methacrylic.

  Commercially available products include, for example, an alkyl acrylate polymer, Aculin 33 (ISP); a (meth) acrylic acid / (meth) acrylic acid alkyl copolymer such as Carbopol 1382, Pemlen TR-1, and Pemlen TR-. 2 (Noveon INC.). Examples of the copolymer of one or more monomers of alkyl acrylate and / or alkyl methacrylate and polyoxyethylene alkyl ether include alkyl acrylate / alkyl methacrylate / polyoxyethylene stearyl ether copolymer. As the commercial product, Aculin 22 (ISP) and the like can be mentioned.

The polymer of component (B) can use 1 or more types, and it is 0.01 to 1 mass% in the whole composition, Furthermore, 0.05 to 0.5 mass% contains, and emulsion stability is favorable. This is preferable.
The mass ratio of the components (A) and (B) is (A) / (B) = 40/1 to 1/1, and more preferably 20/1 to 1/1. This is preferable.

  Among the components (C) used in the present invention, examples of the paraoxybenzoic acid ester include methyl paraoxybenzoate, ethyl paraoxybenzoate, propyl paraoxybenzoate, butyl paraoxybenzoate, isopropyl paraoxybenzoate, isobutyl paraoxybenzoate and the like. It is done. As the component (C), phenoxyethanol may be a commercially available product such as Hisolv EPH (Matsumoto Kosho).

As the component (C), one or more kinds can be used, and a combination of paraoxybenzoic acid ester and phenoxyethanol can also be used.
The component (C) is preferably contained in the total composition in an amount of 0.01 to 2% by mass, and more preferably 0.1 to 1% by mass in terms of antiseptic effects.
The mass ratio of the components (A) and (C) is (A) / (C) = 40/1 to 1/10, preferably 20/1 to 1/1. Outside this range, the moisture retention and antiseptic properties deteriorate.

  The surfactant of component (D) used in the present invention is HLB 8 or less, preferably HLB 2-7. Here, the HLB of the nonionic surfactant is calculated by the following Kawakami equation.

  Specifically, glyceryl fatty acid esters such as glyceryl myristate, glyceryl monostearate, glyceryl monoisostearate, glyceryl monooleate; sorbitan monolaurate, sorbitan monooleate, sorbitan monoisostearate, sorbitan monostearate, etc. Examples include sorbitan fatty acid esters; polyoxyethylene hydrogenated castor oil such as POE (5) hydrogenated castor oil, POE (7.5) hydrogenated castor oil, POE (10) hydrogenated castor oil, and the like.

One or more surfactants of component (D) can be used, and the total composition contains 0.01 to 2% by mass, and more preferably 0.05 to 1% by mass in terms of emulsion stability. preferable.
The mass ratio of components (A) and (D) is (A) / (D) = 80/1 to 1/1, and further 40/1 to 1/1. It is preferable in terms of the effect of suppressing crystal precipitation and the stability of emulsion.

  It is preferable that the water of a component (E) is contained in 40-99 mass% in the whole composition, and also 50-90 mass%.

  The main component of the aqueous phase used in the oil-in-water emulsion composition of the present invention is water, but other than that, lower alcohols having 1 to 4 carbon atoms such as ethanol and propanol, and water-soluble 2 to 4 valent polyvalents. Alcohols such as alcohol can also be included. Such polyhydric alcohols include glycerin, 1,3-butylene glycol, propylene glycol, dipropylene glycol, diglycerin, 1,2-pentanediol, xylit, sorbit, polyethylene glycol, and the like.

  The total content of the water phase component in the oil-in-water emulsion composition of the present invention is 60 to 99.9% by mass and further 65 to 95% by mass in the total composition from the viewpoint of moisture retention and feeling of use (no stickiness). %, Particularly 70 to 90% by mass.

  The oil-in-water emulsion composition of the present invention can further contain components usually used in emulsion compositions. For example, a carboxy vinyl polymer, sodium alginate, carrageenan, carboxymethyl cellulose, hydroxyethyl cellulose, guar gum, xanthan gum, carboxymethyl chitosan, sodium hyaluronate and the like can be contained as a thickener.

  In addition, various extracts are available such as buckwheat extract, licorice extract, aloe extract, horsetail extract, tea extract, cucumber extract, clove extract, carrot extract, hamamelis extract, placenta extract, seaweed extract, maronier extract, yuzu extract, eucalyptus extract, asnalro An extract or the like can be contained.

  Further, neutralizing agents such as potassium hydroxide, sodium hydroxide, triethanolamine, sodium carbonate; pH adjusting agents such as citrate, tartrate, lactate, phosphate, succinate, adipate; ascorbine Water-soluble vitamins such as acids, nicotinic acid amides and nicotinic acid; pigments, fragrances and the like can be contained.

  The emulsified composition of the present invention includes the components (B), (C), and (E), which are prepared by mixing and dissolving the oil phase components including the components (A) and (D). It can be produced by a method such as adding a water phase component to a solution obtained by mixing and heating, heating as necessary, and treating with a homomixer to obtain a uniform emulsion composition.

  The emulsified composition of the present invention can be applied as a cosmetic based on the form of an oil-in-water (O / W) emulsified composition, for example, dosage forms such as emulsions, creams, cleansing creams, emulsified foundations, etc. Can take form.

Examples 1-6
An oil-in-water emulsion composition having the composition shown in Table 1 was produced, and the crystal precipitation state and storage stability of ceramide and a ceramide-like compound were evaluated. The results are also shown in Table 1.

(Manufacturing method)
Components (6), (7), and (15) were added to component (14), and components (3) to (5) were added to those heated and dissolved at 80 ° C., and dissolved at 80 ° C. To this, component (13) was added to prepare an aqueous phase. Separately, components (1), (2) and (8) to (12) were uniformly mixed at 80 ° C. to prepare an oil phase. At 80 ° C., this oil phase was added to the previously prepared aqueous phase and pre-emulsified. After uniformly adjusting the emulsified particles with a homomixer, deaeration and filtration were performed to obtain an oil-in-water emulsion composition.

(Evaluation methods)
(1) Crystal precipitation state:
About the obtained emulsified composition, the presence or absence of crystal precipitation was evaluated visually and it determined with the following references | standards.
○: No crystal precipitation is observed.
X: Crystal precipitation is clearly observed.

(2) Storage stability:
The obtained emulsified composition was stored at 5 ° C., room temperature (25 ° C.), and 50 ° C. for 1 month, and then evaluated for the presence or absence of changes in properties (thickening, gelation, separation, crystal precipitation, etc.). .
◯: No change in properties at 5 ° C., room temperature (25 ° C.), or 50 ° C.
(Triangle | delta): A little property change is recognized in 5 degreeC, room temperature (25 degreeC), and 50 degreeC.
X: Change in properties is clearly observed at 5 ° C., room temperature (25 ° C.), and 50 ° C.

  From the results of Table 1, in all of the emulsified compositions of Examples 1 to 6, crystals of ceramide and a ceramide-like compound did not precipitate, and the storage stability was good. In contrast, in Comparative Examples 1 and 2 not containing the component (D) and in Comparative Example 3 not containing the component (B), precipitation of crystals was observed.

Example 7 (milky lotion)
An emulsion having the composition shown in Table 2 was produced. The obtained emulsion was good in the crystal precipitation state and storage stability.

(Manufacturing method)
Glycerin, eucalyptus extract and component (C) were added to purified water, and the carboxyvinyl polymer and component (B) were added to what was dissolved by heating at 80 ° C. and dissolved at 80 ° C. To this was added potassium hydroxide to prepare an aqueous phase. Separately, components (A), (D), squalane, olive oil, cholesterol, dimethylpolysiloxane and a flavor were uniformly mixed at 80 ° C. to prepare an oil phase. At 80 ° C., this oil phase was added to the previously prepared aqueous phase and pre-emulsified. After the emulsified particles were uniformly adjusted with a homomixer, deaeration and filtration were performed to obtain an emulsion.

Example 8 (cream)
Creams having the compositions shown in Table 3 were produced. The obtained cream was good in the crystal precipitation state and storage stability.

(Manufacturing method)
Glycerin, asunalo extract and component (C) were added to purified water, and the component (B) was added to the solution dissolved by heating at 80 ° C. and dissolved at 80 ° C. To this was added potassium hydroxide to prepare an aqueous phase. Separately, components (A) and (D), squalane, olive oil, cetyl alcohol, stearyl alcohol, dimethylpolysiloxane and a flavor were uniformly mixed at 80 ° C. to prepare an oil phase. At 80 ° C., this oil phase was added to the previously prepared aqueous phase and pre-emulsified. After the emulsion particles were uniformly adjusted with a homomixer, deaeration and filtration were performed to obtain a cream.

Claims (4)

The following components (A) to (E):
(A) one or more compounds selected from ceramide and ceramide-like compounds,
(B) a polymer of alkyl acrylate and / or alkyl methacrylate,
(C) paraoxybenzoic acid ester or phenoxyethanol,
(D) Oil-in-water type containing surfactant (E) water of HLB 8 or less and having a mass ratio of components (A) and (C) of (A) / (C) = 40/1 to 1/10 Emulsified composition.   The oil-in-water emulsion composition according to claim 1, wherein the oil phase containing the component (A) in the oil-in-water emulsion composition is 30% by mass or less, and the component (A) is 50% by mass or less in the oil phase. Stuff.   The oil-in-water emulsion composition according to claim 1 or 2, wherein the mass ratio of the components (A) and (B) is (A) / (B) = 40/1 to 1/1.   The oil-in-water emulsion composition according to any one of claims 1 to 3, wherein the mass ratio between the components (A) and (D) is (A) / (D) = 80/1 to 1/1.