JP2008074706A - External preparation for skin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an external preparation for skin, having a characteristic property wherein the external preparation lowers its flowability to change in a gel-like state, when extruded from a pump type container or the like. <P>SOLUTION: This external preparation for skin comprises an acrylic acid-alkyl methacrylate copolymer, one or more surfactants selected from monoalkyl type quaternary ammonium salt type cationic surfactants, and a polyhydric alcohol. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention is an external preparation for skin having excellent characteristics when using a pump-type container, and more specifically, the fluidity is lowered due to the shear force involved in the shear when discharging the contents, and changes into a gel form. The present invention relates to an external preparation for skin having unique properties. In other words, before the share is added, it exhibits sufficient fluidity, and while sucking in bulk in a pump-type container, etc., it smoothly changes to a gel-like shape when discharged, so it will be skin to the hand. It has the advantage that it does not easily cause dripping when applied to.

  An object of the present invention is to obtain an external preparation for skin that exhibits excellent fluidity when used in a pump-type container, and also has excellent usability when applied to the skin.

  When commercializing liquid to mucous liquid preparations with relatively high fluidity, compatibility with bottle containers and pump containers is good. , It may be difficult to use due to liquid dripping. In this case, a method of covering this defect by, for example, infiltrating the contents into cotton or the like in advance is used. On the other hand, when a gel-like to cream-like preparation with low fluidity is commercialized, a container having a wide diameter is used although the usability is good. That is, considering the usability, it is preferable that the fluidity is relatively low. Judging from the compatibility with the container, it is possible to adopt a container that is more convenient when the fluidity is higher. However, since these are contradictory properties, they are technically difficult, and therefore there are few reports on techniques that satisfy them. The development of pharmaceutical technology that takes advantage of the advantages of the producer and the user is always expected as a challenge, but there are few reports.

  As a document relating to this problem, there is an oil-in-water emulsion composition (see Patent Document 1) that has an aqueous physical property and has a creamy feeling. This shows these properties by treating the oil-in-water emulsion composition composed of an amphiphile-surfactant-water system with a strong shearing force. The composition in this document is intended to provide an oil-in-water emulsion composition having physical properties in the form of an aqueous solution and having a creamy feel. The invention of this document requires a special mechanical treatment, and the change in physical properties is an irreversible phenomenon.

JP-A-6-271421

  In the present invention, a method for providing an external preparation for skin having good compatibility with a pump-type container and the like and having excellent usability even when applied to the skin has been intensively studied.

  As a result of researches to solve the above problems, the present inventor has selected at least (A) an acrylic acid / alkyl methacrylate copolymer and (B) a monoalkyl type quaternary ammonium salt type cationic surfactant. It was found that these problems can be solved by using a skin external preparation characterized by containing one or more kinds and (C) a polyhydric alcohol, and the present invention has been completed. is there.

  The skin external preparation of the present invention exhibits a viscous liquid state rich in fluidity upon standing. When this is filled in a pump-type container or the like, that is, when the contents are discharged, a share is applied at the discharge port portion, and at this time, the fluidity is lowered to change to a gel state.

  That is, before the share is added, it has sufficient fluidity, so bulk suction in a pump type container etc. is smooth, and it changes to a gel when discharging, so it is applied to the skin for the hand In this case, it is possible to achieve ideal usability for both the providing side and the using side, which is less likely to cause dripping and easy to use.

  An embodiment of the present invention will be described.

  The (A) acrylic acid / alkyl methacrylate copolymer used in the present invention is a copolymer of acrylic acid and alkyl methacrylate, and includes a hydrophilic part resulting from a carboxyl group, and a lipophilic part resulting from an alkyl group. It is a polymer with a function as an emulsifier having a good emulsifying property and a function as a thickening agent. From BF Goodrich, PEMULEN TR-1 and PEMULEN TR-2 It is commercially available under the trade name. When these are used, it is possible to emulsify the oil in the preparation, and there is a characteristic that a light usability can be obtained. As the acrylic polymer, a carboxyvinyl polymer which is not alkyl-modified is generally used as a thickener for cosmetics. However, in the case of a carboxyvinyl polymer, a monoalkyl type quaternary ammonium salt type cation is used in the preparation. Since an aggregate with a surfactant is easily formed, it is not preferable.

  (A) As a compounding quantity to the skin external preparation of an acrylic acid alkyl methacrylate copolymer, 0.1-3 mass% can preferably be used with respect to the skin external preparation whole quantity, However, 0.1 If it is less than mass%, the gelation phenomenon due to the shear that is a feature of the product of the present invention will not occur, and if it exceeds 3 mass%, the stationary state becomes a gel state, so the characteristics of the present invention are exhibited. Can not. In order to make the most of the characteristics of the present invention, 0.5 to 2% by mass is particularly preferable.

  (B) The monoalkyl type quaternary ammonium salt type cationic surfactant has the following general formula (wherein R1 is an alkyl group or alkenyl group having 8 to 22 carbon atoms, and R2, R3 and R4 are the same or different. An alkyl group having 1 to 3 carbon atoms which may be substituted with a hydroxyl group or a benzyl group, and X represents a halogen atom) can be used.

  (B) Specific examples of the monoalkyl type quaternary ammonium salt type cationic surfactant include lauryl trimethyl ammonium chloride, myristyl trimethyl ammonium chloride, cetyl trimethyl ammonium chloride, stearyl trimethyl ammonium chloride, behenyl trimethyl ammonium chloride, odor Lauryltrimethylammonium bromide, myristyltrimethylammonium bromide, cetyltrimethylammonium bromide, stearyltrimethylammonium bromide, behenyltrimethylammonium bromide, myristyldimethylbenzylammonium chloride, cetyldimethylbenzylammonium chloride, octyldihydroxyethylmethylammonium chloride, 2 -Decyltetradecyltrimethylammonium chloride, 2-dodecylhexadecyltrimethyl chloride Ammonium and the like. Among these, liquid to paste-like lauryltrimethylammonium chloride, myristyltrimethylammonium chloride, cetyltrimethylammonium chloride, and stearyltrimethylammonium chloride are preferable at room temperature.

  (B) As a compounding quantity to the skin external preparation of a monoalkyl type | mold quaternary ammonium salt type cationic surfactant, Preferably 1-7 mass% can be used with respect to the skin external preparation whole quantity, but 1 If it is less than mass%, the sufficient gelation phenomenon due to the shear, which is a feature of the product of the present invention, does not occur, and if it exceeds 7 mass%, it already becomes a gel and cannot exhibit the characteristics of the present invention. In order to make the most of the characteristics of the present invention, 2 to 6% by mass is particularly preferable.

  Further, the blending ratio of (A) acrylic acid / alkyl methacrylate copolymer and (B) monoalkyl type quaternary ammonium salt type cationic surfactant is 1: 1 to 1: 4 in mass ratio. preferable. If this blending ratio is deviated, the gelation phenomenon due to the shear, which is a feature of the product of the present invention, does not occur.

  (C) As a polyhydric alcohol, 1 type, or 2 or more types chosen from glycerol, 1, 3- butylene glycol, diglycerol, and a dipropylene glycol can be used.

  (C) As a compounding quantity to the skin external preparation of a polyhydric alcohol, Preferably, 8-45 mass% can be used with respect to the skin external preparation whole quantity. If the amount is less than 8% by mass, aggregates are easily generated in the preparation, and the state is unstable. In particular, at a low temperature of 10 ° C. or less, it may become significantly white and cloudy. If it exceeds 45% by mass, stickiness appears remarkably and the skin feels uncomfortable and uncomfortable. 10-40 mass% is especially preferable.

  The skin external preparation of the present invention has a Brookfield rotational viscometer (for example, a viscometer manufactured by Tokyo Seiki Seisakusho Co., Ltd.) as long as components other than (A), (B), and (C) do not affect fluidity. The viscosity measured at a measurement temperature of 25 ° C., a rotor number of 4 and a rotational speed of 6 rpm is 25000 mPa · s or less. In the external preparation for skin of the present invention, the formation of a gel structure is promoted and an increase in viscosity is observed as a stronger shearing force is applied. The pump type container used for the external preparation for skin is generally used with an inner diameter of 0.3 to 1.5 mm. The viscosity immediately after being discharged from the pump-type container discharge port is 30000 to 60000 mPa · s when measured under the same conditions as when standing, and a clear increase is observed. In addition, this phenomenon is reversible and has the property of returning to the original fluidity after standing for a while. Because it shows such characteristics, even when a gel structure is formed by applying a large shear force during the filling of the container or at the time of manufacture, it returns to the original physical properties by leaving it still. It is also an advantage that the problem caused by this does not occur.

  The skin external preparation of the present invention includes (A) an acrylic acid / alkyl methacrylate copolymer as an essential component, (B) a monoalkyl type quaternary ammonium salt type cationic surfactant, and (C) a polyhydric alcohol. In addition, other ingredients blended in general cosmetics and quasi-drugs, such as fats and oils, surfactants, moisturizers, inorganic powders, organic powders, as long as the effects of the present invention are not impaired. An ultraviolet absorber, a pH adjuster, a chelating agent, a drug, a fragrance, a resin, and other alcohols can be appropriately blended as necessary.

  The external preparation for skin of the present invention comprises (B) a monoalkyl type quaternary ammonium salt type cationic surfactant that is uniformly mixed and dissolved in (C) polyhydric alcohol, and then (A) acrylic acid / methacrylic acid. It is preferably produced by adding an aqueous solution of an acid alkyl copolymer. When (A) is allowed to act directly on (B), there is a tendency that aggregates are easily formed by the interaction.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, the skin external preparation of this invention is not limited to these.

  Table 1 shows examples of the present invention and comparative examples 1 to 3 as a comparison. Table 2 shows the evaluation results.

Production method:
Dissolve component 3 in 4 purified water. After components 1 and 2 are mixed and dissolved by heating, an aqueous solution of components 3 and 4 prepared in advance is added to mix and homogenize.

  From the above results, it was confirmed that the comparative example does not exhibit the characteristics of the present invention.

  Next, the skin external preparation of Example 1 was subjected to a shear test. Pump containers having inner diameters of 0.3 mm, 0.9 mm, and 1.5 mm were prepared, and changes in viscosity before and after discharge were measured. The viscosity was measured using a Brookfield rotary viscometer manufactured by Tokyo Seiki Seisakusho Co., Ltd. at a measurement temperature of 25 ° C., a rotor number of 4 and a rotational speed of 6 rpm. Since the gelation phenomenon in the present invention is reversible, it was measured immediately after ejection. The viscosity after 5 minutes of standing was also measured. The results are shown in Table 3.

  From the above results, the characteristics of the present invention could be confirmed. In addition, an increase in viscosity was observed as the strong shear was applied. It was also confirmed that the properties returned to their original properties after standing.

  Hereinafter, other examples of the present invention will be described.

[Example 2] Gel cosmetic 1. Glycerin 25.0 (mass%)
2. Stearyltrimethylammonium chloride 4.0
3. Acrylic acid / alkyl methacrylate copolymer 1.4
4). Purified water 69.0
5. Ethanol 0.4
6). Methyl paraoxybenzoate 0.1
7). Fragrance 0.1
Production method:
Ingredient 3 is dissolved in purified water of ingredient 4. After components 1 and 2 are mixed and heated and dissolved, an aqueous solution of components 3 to 4 prepared in advance is added to mix and homogenize, and components 5 to 7 are added.

[Example 3] Gel cosmetic 1.1,3 butylene glycol 10.0 (mass%)
2. Glycerin 15.0
3. Cetyltrimethylammonium chloride 1.0
4). Stearyltrimethylammonium chloride 3.0
5. Acrylic acid / alkyl methacrylate copolymer 1.5
6). Purified water 68.9
7). Ethanol 0.4
8). Methyl paraoxybenzoate 0.1
9. Fragrance 0.1
Production method:
Ingredient 5 is dissolved in purified water of ingredient 6. After components 1 to 4 are mixed and dissolved by heating, an aqueous solution of components 5 to 6 prepared in advance is added and mixed, and components 7 to 9 are added.

[Example 4] Gel cosmetic 1. Diglycerin 5.0 (mass%)
2. Glycerin 10.0
3. Stearyltrimethylammonium chloride 3.0
4). Acrylic acid / alkyl methacrylate copolymer 1.2
5. Purified water 80.2
6). Ethanol 0.4
7). Methyl paraoxybenzoate 0.1
8). Fragrance 0.1
Production method:
Ingredient 4 is dissolved in purified water of ingredient 5. After components 1 to 3 are mixed and dissolved by heating, an aqueous solution of components 4 to 5 prepared in advance is added to mix and homogenize, and components 6 to 8 are added.

  It was confirmed that the skin external preparation of the present invention also exhibits a gelation phenomenon due to the application of the shear, which is a characteristic of the present invention, in Examples 2 to 4 described above.

Claims (5)

It is a composition having a viscosity of 25000 mPa · s or less when filled in a pump-type container, and the viscosity immediately after that shows a viscosity of 30000-60000 mPa · s due to the shearing force when discharged from the pump-type container discharge port. An external preparation for skin. The skin external preparation according to claim 1, comprising at least (A), (B) and (C).
(A) Acrylic acid / alkyl methacrylate copolymer (B) One or more selected from monoalkyl type quaternary ammonium salt type cationic surfactants (C) Polyhydric alcohol (A) 0.5-2 mass%, (B) 2-6 mass%, (C) 10-40 mass% containing the said component (A), (B) and (C), (A) and The external preparation for skin according to claim 1 or 2, wherein the blending ratio of (B) is 1: 1 to 1: 4 by mass ratio. (C) The external preparation for skin according to any one of claims 1 to 3, wherein the polyhydric alcohol is one or more selected from glycerin, 1,3-butylene glycol, diglycerin and dipropylene glycol. The skin external preparation according to claim 1, wherein the component (B) is uniformly mixed and dissolved in the component (C), and then the aqueous solution of the component (A) is added and mixed. Production method.