JP4808445B2 - W / O type emulsion composition - Google Patents

Description

  The present invention relates to a W / O emulsion composition that is excellent in terms of storage stability, skin safety, and usability.

  In the W / O emulsion, surfactant molecules cover the water droplets dispersed and atomized in the oil phase to maintain stability. However, it is difficult to obtain an emulsion that is stable for a long time because it is easily affected by conditions such as the properties, viscosity, and temperature of the oil and the water phase and the oil phase are easily separated. In addition, low molecular surfactants may adversely affect the skin, and there is a problem that a surfactant sufficient to keep the emulsion sufficiently stable cannot be blended.

On the other hand, a homopolymer of 2-methacryloyloxyethyl phosphorylcholine (hereinafter abbreviated as MPC) represented by the formula [1] or a copolymer of MPC and a hydrophilic monomer or a hydrophobic monomer is applied to the skin. It is known that it exhibits a moisturizing effect and a rough skin improving effect and can be used as a cosmetic (see, for example, Patent Documents 1 and 2).

  Further, it is known that when a MPC homopolymer is used, a stable multilayer emulsion composition can be formed and is suitable for cosmetics and the like (see, for example, Patent Document 3). Furthermore, it is disclosed that a copolymer of MPC and a hydrophobic monomer can be used as a solubilizer, an emulsifier, and a dispersant (see, for example, Patent Documents 4 and 5).

Japanese Patent Laid-Open No. 5-70321 JP-A-6-157269 Japanese Patent Laid-Open No. 10-45525 Japanese Patent Laid-Open No. 10-109029 JP-A-12-119130

  However, the emulsions disclosed in these publications have problems such as limitations on oil components, and it has been difficult to obtain a stable W / O emulsion. An object of the present invention is to provide a W / O emulsion composition that is excellent in terms of storage stability, skin safety, and usability.

  As a result of intensive studies in view of the above matters, the present inventors have used (a) a copolymer obtained by polymerizing MPC and a hydrophobic methacrylate as an emulsifier, and (b) a polyhydric alcohol and (c) To obtain the knowledge that a combination of a higher alcohol and / or a higher fatty acid can provide a W / O emulsion composition that is superior in terms of storage stability, skin safety, and usability, and to complete the present invention. It came.

  That is, the present invention uses (a) a copolymer obtained by polymerizing MPC and hydrophobic methacrylic acid ester as an emulsifier, and further contains (b) a polyhydric alcohol and (c) a higher alcohol and / or a higher fatty acid. It is an invention that provides a W / O emulsion composition.

  Hereinafter, the configuration of the present invention will be described in detail.

The weight average molecular weight of the copolymer obtained by polymerizing (a) MPC (shown by the formula [1]) and hydrophobic methacrylic acid ester used in the present invention is in the range of 5,000 to 5,000,000. It is preferable that it is in the range of 10,000 to 1,000,000. When the weight average molecular weight of the copolymer is less than 5,000, it is not preferable because sufficient emulsifying ability cannot be exhibited. When the weight average molecular weight of the copolymer is larger than 5,000,000, the dispersibility of the copolymer is not preferable. Is not preferable because it significantly decreases. Further, the constituent molar ratio of MPC and hydrophobic methacrylic acid ester in the copolymer is preferably in the range of 1: 1 to 1: 9. If the molar ratio of MPC and hydrophobic methacrylate in the copolymer is more than 50:50, it is not preferable because a stable W / O emulsion is difficult to prepare, and the MPC in the copolymer is not preferred. When the molar ratio of MPC is less than 10:90, the emulsion stability of the W / O emulsion is lowered, which is not preferable. Moreover, it is preferable that it is the range of 12-24 about carbon number of the alkyl chain which the hydrophobic methacrylic acid ester in a copolymer has. When the number of carbon atoms of the alkyl chain of the hydrophobic methacrylate in the copolymer is less than 12, it is not preferable because a stable W / O emulsion is difficult to prepare, and the alkyl of the hydrophobic methacrylate in the copolymer is not preferred. If the chain has more carbon atoms than 24, the copolymer dispersibility is lowered, which is not preferable. Specific examples of hydrophobic methacrylates include, but are not limited to, lauryl methacrylate, tridecyl methacrylate, myristyl methacrylate, palmityl methacrylate, stearyl methacrylate, behenyl methacrylate, isostearyl methacrylate, and oleyl methacrylate. is not.

  If the copolymer of (a) MPC and hydrophobic methacrylic acid ester used in the present invention is more specifically exemplified, it can be synthesized with reference to JP-A-12-119130, and is a commercial product. Lipidure series manufactured by Nippon Oil & Fat Co., Ltd. can also be used.

  Although the compounding quantity of the copolymer of (a) MPC and hydrophobic methacrylic acid ester used for this invention is not specifically limited, It is preferable to contain in the range of 0.01-10 weight%, 0.1-5 weight It is more preferable that it is contained in the range of%. When the amount is less than 0.01%, sufficient emulsification stability may not be obtained. When the amount is more than 10%, significant emulsification stability corresponding to the amount cannot be obtained. It is not preferable because the feeling of use is impaired such as stickiness.

  The production method of the W / O type emulsion composition in the present invention is not particularly limited and can be produced by a conventional method, but preferably W / O type emulsion having excellent storage stability when prepared by the production method as described below. A composition is obtained. First, (a) a copolymer of MPC and hydrophobic methacrylic acid ester is dispersed in (b) a polyhydric alcohol and (c) a higher alcohol and / or a higher fatty acid and added to the oil component. Thereafter, the aqueous component is added with stirring to perform emulsification to obtain a W / O emulsion. The emulsification temperature at this time is preferably 50 to 90 ° C, more preferably 60 to 85 ° C, whereby a stable W / O emulsion having finer particles can be prepared.

  As for the type of (b) polyhydric alcohol used in the present invention, one or more selected from 1,3-butylene glycol, glycerin, propylene glycol, 1,2-pentylene glycol and 1,2-hexylene glycol. Is preferable because the component (a) can be quickly dispersed.

  As for the type of (c) higher alcohol and / or higher fatty acid used in the present invention, those in which the alkyl chain has 12 to 24 carbon atoms and is in a liquid state at room temperature quickly disperses the component (a). This is preferable because it can be performed. Examples include, but are not limited to, isostearyl alcohol, oleyl alcohol, octyldodecyl alcohol, hexyl decyl alcohol, isostearic acid, oleic acid and the like.

  In the present invention, the content of (b) polyhydric alcohol and (c) higher alcohol and / or higher fatty acid is preferably 4: 1 to 1: 4 by weight. When the content of the component (b) is larger than 4: 1, it is not preferable because a stable W / O emulsion is difficult to prepare, and when the content of the component (b) is smaller than 1: 4, sufficient emulsion stability is obtained. Is not preferred because it is difficult to obtain.

  Although the sum total of content of the component of (b) and the component of (c) is not specifically limited, It is preferable to contain in the range of 0.1-50 weight%, and it contains in the range of 0.5-30 weight% More preferably. If it is less than 0.1%, it is not preferred because sufficient emulsification stability is difficult to obtain, and if it is more than 50%, it is not preferred because the feeling of use such as stickiness when applied to the skin is impaired.

  In addition to the essential components described above, the W / O emulsion composition of the present invention is used for various components used in normal cosmetics, quasi-drugs, pharmaceuticals, etc., such as other surfactants, oily components, humectants, Adhesives, chelating agents, medicinal ingredients, preservatives, dyes, pigments, powders, pH adjusters, ultraviolet absorbers, antioxidants, fragrances, and the like can be appropriately blended.

  If the various components which can be mix | blended with the W / O type emulsion composition of this invention are illustrated further more concretely, as an oil-based component, hydrocarbon, vegetable oil, higher fatty acid ester, silicone oil, fluorine-type oil, triglyceride And higher alcohols. On the other hand, examples of the aqueous component include polymer substances, alcohols, polyhydric alcohols and the like in addition to water.

  The W / O type emulsified composition of the present invention can be used as a skin external preparation for cosmetics, quasi-drugs, pharmaceuticals and the like.

  The present invention is a W / O emulsion composition that is excellent in terms of storage stability, skin safety, and usability.

  The present invention will be described in more detail with reference to examples and comparative examples below, but the present invention is not limited to the following examples. In addition, content of each component in prescription shall be weight%.

In Table 1, preparations were prepared by blending (a) a copolymer of MPC and a hydrophobic methacrylate ester (using Lipidure-S manufactured by Nippon Oil & Fats Co., Ltd.) in various proportions, and the changes over time and the feeling of use were examined. The results are shown.
In addition, about the manufacturing method of a formulation, it performed in the following procedures. First, at a temperature of 70 ° C., (a) a copolymer of MPC and hydrophobic methacrylate is dispersed in (b) a polyhydric alcohol and (c) a higher alcohol and / or a higher fatty acid, and then added to the oil component. The aqueous phase heated to 70 ° C. was added with stirring and then uniformly emulsified with a homogenizer. This was cooled to 30 ° C. to obtain the intended W / O emulsion preparation.
Each time-lapse observation was evaluated after 1 year at room temperature and after 2 months at 50 ° C., and the following four stages of storage stability evaluation items were used as indicators.

Storage stability evaluation evaluation item A: Almost no change in phase state is observed.
○: A slight increase in the emulsified particle diameter can be confirmed by observation with a microscope.
Δ: Phase separation cannot be confirmed, but a remarkable increase in the emulsified particle diameter can be confirmed by observation with a microscope.
X: It can also confirm visually that it isolate | separated into two phases.

Moreover, about the usability evaluation, 20 panelists evaluated using this invention emulsion composition actually. The spreadability at the time of application, viscosity, and moisture retention after application were scored according to the following five levels of usability evaluation items.

Usability evaluation items 5 points: very good 4 points: good 3 points: normal 2 points: bad 1 point: very bad

The total score obtained was finally judged according to the following four-level evaluation of feeling of use.

Usability score evaluation A: The total score is 80 points or more, and the usability is very good.
○: The total score is 70 points or more, and the feeling of use is good.
Δ: The total score is 50 points or more, and the feeling of use is bad.
X: The total score is 50 or less, and the feeling of use is very bad.

In addition, about each sample, it was normally used and the raw material actually marketed was employ | adopted.

  Table 2 shows the results of examining the change over time and the feeling of use of preparations prepared with various content ratios of (b) polyhydric alcohol and (c) higher alcohol and / or higher fatty acid. The production method was performed in the same manner as in Table 1 above, and the storage stability and usability evaluation were also performed using the same index.

  Table 3 shows the results of preparing preparations containing various ratios of (b) polyhydric alcohols and (c) higher alcohols and / or higher fatty acids in various proportions and examining changes over time and feeling of use. In addition, regarding the manufacturing method, it carried out similarly to the above-mentioned Table 1 and Table 2, and the storage stability and the usability evaluation were also performed with the same index.

  Table 4 shows the results of examining the change over time and feeling of use when (a) the copolymer of MPC and hydrophobic methacrylate is replaced with another lipophilic surfactant or oil-soluble thickener. . In addition, regarding the manufacturing method, it carried out similarly to the above-mentioned Table 1 to Table 3, and storage stability and usability evaluation were also performed with the same index.

  From the results of Table 1 to Table 4, it was revealed that the product of the present invention is a useful W / O type emulsion composition having excellent storage stability and usability.

  Examples for describing the present invention in detail are given below, but the present invention is not limited thereto.

Moisturizing cream Blending ingredients Blending amount (% by weight)
(1) MPC (30) / stearyl methacrylate (70) 1.0
(2) Isostearyl alcohol 1.0
(3) 1,3-butylene glycol 4.0
(4) Squalane 11.3
(5) Octyldodecyl myristate 8.0
(6) Methylphenylpolysiloxane 4.0
(7) Fragrance 0.2
(8) Sodium chloride 0.4
(9) Potassium aluminum sulfate 0.1
(10) Dipotassium glycyrrhizinate 0.1
(11) Glycerin 8.0
(12) Paraben appropriate amount (13) Purified water residue

  [Production Method] (1) to (3) are dispersed and then added to (4) to (7) and heated to 70 ° C. (8) to (13) heated to 70 ° C. are added, emulsified and uniformly dispersed with a homogenizer, and then cooled to 30 ° C.

Latex Blending ingredients Blending amount (wt%)
(1) MPC (10) / Lauryl methacrylate (90) 0.2
(2) Isostearic acid 0.5
(3) Glycerin 1.0
(4) POE (4) glyceryl monostearate 0.1
(5) Cyclomethicone 5.0
(6) Neopentyl glycol dicaprate 5.0
(7) Fragrance 0.1
(8) Magnesium sulfate 0.5
(9) Ascorbic acid magnesium phosphate 0.1
(10) Carboxyvinyl polymer 0.2
(11) Decaglyceryl monostearate 0.5
(12) 1,3-butylene glycol 5.0
(13) Paraben appropriate amount (14) Edetate appropriate amount (15) Aminomethylpropanediol appropriate amount (16) Purified water residue

  [Production Method] (1) to (3) are dispersed and then added to (4) to (7) and heated to 80 ° C. (8) to (16) heated to 80 ° C. are added, emulsified and uniformly dispersed with a homogenizer, and then cooled to 30 ° C.

Whitening cream Ingredient Ingredient Amount (wt%)
(1) MPC (50) / behenyl methacrylate (50) 3.0
(2) Oleyl alcohol 3.0
(3) Propylene glycol 5.0
(4) Liquid paraffin 10.0
(5) Dimethicone 5.0
(6) Fragrance 0.2
(7) Sodium citrate 3.0
(8) Ascorbic acid magnesium phosphate 3.0
(9) Sodium polyphosphate 0.1
(10) Decaglyceryl monooleate 0.5
(11) 1,3-butylene glycol 5.0
(12) Paraben appropriate amount (13) Purified water residue

  [Production Method] (1) to (3) are dispersed and then added to (4) to (6) and heated to 80 ° C. (7) to (13) heated to 80 ° C. are added, emulsified and uniformly dispersed with a homogenizer, and then cooled to 30 ° C.

Cosmetic liquid Blending ingredients Blending amount (% by weight)
(1) MPC (30) / stearyl methacrylate (70) 1.0
(2) Octyldodecyl alcohol 3.0
(3) 1,2-pentylene glycol 2.0
(4) Sorbitan monooleate 1.0
(5) Liquid paraffin 15.0
(6) Isotridecyl isononanoate 23.0
(7) Tocopherol acetate 0.3
(8) Fragrance 0.2
(9) Glycerin 5.0
(10) Edetoate appropriate amount (11) Paraben appropriate amount (12) Phenoxyethanol appropriate amount (13) Purified water residue

  [Production Method] (1) to (3) are dispersed and then added to (4) to (8) and heated to 75 ° C. (9) to (13) heated to 75 ° C are added, emulsified, and uniformly dispersed with a homogenizer, and then cooled to 30 ° C.

Moisturizing cream Blending ingredients Blending amount (% by weight)
(1) MPC (30) / stearyl methacrylate (70) 3.0
(2) Isostearyl alcohol 7.0
(3) 1,3-butylene glycol 14.0
(4) Squalane 12.0
(5) Isononyl isononanoate 10.0
(6) Methylphenylpolysiloxane 5.0
(7) Fragrance 0.2
(8) Dipropylene glycol 8.0
(9) Paraben appropriate amount (10) Purified water residue

  [Production Method] (1) to (3) are dispersed and then added to (4) to (7) and heated to 70 ° C. (8) to (10) heated to 70 ° C are added and emulsified, and then cooled to 30 ° C.

  The products of the present invention shown in Examples 2 to 6 were W / O type emulsion compositions excellent in terms of storage stability, skin safety, and feeling of use.

  The W / O emulsion composition of the present invention is excellent in terms of storage stability, skin safety, and feeling of use, and can be used as a skin external preparation in cosmetics, quasi drugs, pharmaceuticals, and the like.

Claims (6)

(A) A copolymer of 2-methacryloyloxyethyl phosphorylcholine (shown by the formula [1]) and a hydrophobic methacrylate ester is dispersed in (b) a polyhydric alcohol and (c) a higher alcohol and / or a higher fatty acid. The oily component is added, and then the aqueous component is added to emulsify. (A) is 0.01 to 10% by weight of the total, and (b) and (c) are all components. A W / O type emulsion composition having a content of 0.05 to 25% by weight and a content ratio of (b) to (c) of 1: 0.25 to 1: 4 .

(A) in 2-methacryloyloxy copolymer of acryloyloxyethyl phosphorylcholine and hydrophobic methacrylic acid ester of claim 1, wherein the number of carbon atoms in the alkyl chain with hydrophobic methacrylic acid ester is 12 to 24 W / O type emulsion composition. (B) The polyhydric alcohol is one or more selected from 1,3-butylene glycol, glycerin, propylene glycol, 1,2-pentylene glycol, and 1,2-hexylene glycol. Item 3. The W / O emulsion composition according to any one of Items 1 to 2 . (C) The alkyl chain of the higher alcohol and / or higher fatty acid has 12 to 24 carbon atoms, and is in a liquid state at room temperature, W according to any one of claims 1 to 3 / O type emulsified composition. 5. The component of (b) polyhydric alcohol and (c) higher alcohol and / or higher fatty acid is 0.25 to 15% by weight of the whole, according to claim 1. W / O type emulsion composition. (A) a copolymer of 2-methacryloyloxyethyl phosphorylcholine (shown by the formula [1] according to claim 1) and a hydrophobic methacrylic acid ester ; (b) a polyhydric alcohol and (c) a higher alcohol and / or It is characterized by being dispersed in a higher fatty acid, added to an oil component, and then emulsified by adding an aqueous component, wherein (a) is 0.01 to 10% by weight of the total, (b) and (c) Each component is 0.05 to 25% by weight, and the content ratio of (b) and (c) is 1: 0.25 to 1: 4 . Manufacturing method.