Water-in-oil emulsion composition containing salicylic acid

Abstract

The present invention aims to provide a water-in-oil emulsion composition which does not cause separation after a long period of time even if a large amount of salicylic acid is added, is stable, does not deteriorate in usability over time, and can be applied to color cosmetics. The present invention relates to a water-in-oil emulsion composition, characterized in that it contains (a) 0.5 mass % or more of salicylic acid; (b) an organic modified clay mineral; (c) a sorbitan fatty acid ester; and (d) a colorant.

Description

Technical Field

[0001] The present invention relates to a water-in-oil emulsion composition, and more particularly to a water-in-oil emulsion composition capable of stably blending a large amount of salicylic acid and an emulsified cosmetic using the same. Background Art

[0002] Salicylic acid is considered to be an effective compound for treating relatively mild acne. In addition, salicylic acid derivatives such as 4-methoxysalicylate exert a whitening effect by improving / preventing abnormal melanin deposition when applied to the skin. However, when salicylic acid or its derivatives are formulated into a water-in-oil emulsion composition, there is a problem that emulsified particles merge over time, making the system unstable, resulting in separation (separation).

[0003] Patent Document 1 discloses a water-in-oil skin whitening cosmetic formulated with 4-methoxysalicylate as a salicylic acid derivative. The cosmetic is formulated by combining and formulating an organic modified clay mineral with oleic acid and / or isostearic acid, and is believed to be non-sticky, have a moist feel during use, be independent of the material of the container in which it is stored, and have excellent stability over time.

[0004] However, if the 4-methoxysalicylate in the cosmetics of Patent Document 1 is replaced with salicylic acid, it can be seen that the viscosity of the system increases over time and the use tends to be heavy. In addition, the cosmetics of Patent Document 1 are skin care cosmetics for the purpose of whitening, and are not intended to be combined with colorants (powders) such as pigments. In fact, there is no record of colorants in Patent Document 1, and no colorants are combined in the specific recorded formulas. Therefore, it is unclear what changes will occur when trying to combine the colorants with the cosmetics of Patent Document 1 and apply them to color cosmetics.

[0005] Patent Document 1: Japanese Patent No. 5164292 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] Therefore, an object of the present invention is to provide a water-in-oil emulsion composition which does not cause separation over a long period of time even if a large amount of salicylic acid is added, is stable, does not deteriorate in usability over time, and can be used for makeup cosmetics.

[0008] Solutions for solving problems

[0009] As a result of repeated and intensive studies to solve the above problems, the present inventors have found that by adding sorbitan fatty acid ester to a water-in-oil emulsion composition containing 0.5% by mass or more of salicylic acid, an organically modified clay mineral and a colorant, a water-in-oil emulsion composition that is stable for a long time and can maintain good usability can be obtained, thereby completing the present invention.

[0010] That is, the present invention provides a water-in-oil emulsion composition, characterized in that it contains:

[0011] (a) 0.5 mass % or more of salicylic acid;

[0012] (b) organically modified clay minerals;

[0013] (c) sorbitan fatty acid esters; and

[0014] (d) Pigment.

[0015] Effects of the Invention

[0016] The composition of the present invention is extremely stable over time even when containing salicylic acid, which is considered to have a tendency to destroy the emulsified state of water-in-oil type, at a relatively high concentration. At the same time, the viscosity changes little over time, and good usability can be maintained for a long time. Furthermore, it does not cause streaky color unevenness, and is a composition particularly suitable for color cosmetics. DETAILED DESCRIPTION

[0017] As described above, the water-in-oil emulsion composition of the present invention contains (a) salicylic acid, (b) an organically modified clay mineral, (c) a sorbitan fatty acid ester and (d) a colorant as essential components.

[0018] (a) Salicylic acid

[0019] Salicylic acid is considered to be effective in treating relatively mild acne and is a known ingredient that has been incorporated into cosmetics for a long time.

[0020] In conventional cosmetics, salicylic acid is only incorporated in a small amount, but the composition of the present invention also has the characteristic of being able to stably incorporate at least 0.5% by mass of salicylic acid. The amount of salicylic acid incorporated in the composition of the present invention is 0.5% by mass or more, and the upper limit of the amount is not particularly limited, but is usually 20% by mass or less, preferably about 10% by mass or less.

[0021] Salicylic acid has low solubility in water. Therefore, when preparing the composition of the present invention, it is preferred to dissolve salicylic acid in an appropriate amount of alcohol (ethanol) and then mix it.

[0022] It should be noted that if the salicylic acid in the composition of the present invention is replaced by a salicylic acid derivative (alkoxysalicylic acid) such as 4-methoxysalicylic acid, the viscosity tends to increase over time and the usability tends to be heavy, which is not preferred. Therefore, the "salicylic acid" of the present invention includes salicylic acid and its salts, but does not include salicylic acid derivatives such as alkoxysalicylic acid.

[0023] (b) Organic modified clay minerals

[0024] As the organic modified clay mineral used in the composition of the present invention, the material formed by adding a quaternary ammonium salt compound by an ion exchange reaction in a natural or synthetic montmorillonite clay mineral such as bentonite is preferred. The organic modified clay mineral is not particularly limited as long as it is pharmaceutically acceptable, and for example, dimethyl ammonium hectorite, benzyl dimethyl stearyl ammonium hectorite, distearyl dimethyl ammonium chloride treated magnesium aluminum silicate, etc. can be listed. As a preferred commercial product, dimethyl di (stearyl) ammonium hectorite sold by Elementis PLC under the name of "Bentone 38VCG", benzyl dimethyl stearyl ammonium hectorite sold by Elementis PLC under the name of "Bentone 27VCG", etc. can be listed.

[0025] The organic modified clay mineral may be added in one or more kinds. The amount of the organic modified clay mineral is preferably 0.1 to 5.0% by mass relative to the total amount of the composition, for example, preferably 1.5 to 5.0% by mass. When the amount is less than 0.1% by mass, the emulsion stability tends to decrease, and when the amount exceeds 5.0% by mass, the emulsion tends to become sticky and the feeling of use tends to deteriorate.

[0026] (c) Sorbitan fatty acid ester

[0027] The sorbitan fatty acid ester used in the composition of the present invention is an ester of a fatty acid having 12 to 20 carbon atoms and sorbitol. Examples of the fatty acid having 12 to 20 carbon atoms include stearic acid, isostearic acid, and sesquiisostearate. Specific examples include sorbitan monoisostearate, sorbitan sesquiisostearate, and the like, and sorbitan sesquiisostearate is preferably used. Commercially available products include "COSMOL 182V" (manufactured by The Nisshin OilliO Group, Ltd.), "EMALEX SPIS-150" (manufactured by NIHON EMULSION Co., Ltd.), and the like.

[0028] The amount of sorbitan fatty acid ester in the composition of the present invention is usually 0.1 to 4.0% by mass, preferably 0.5 to 3.0% by mass, and more preferably 0.5 to 1.5% by mass. If it is less than 0.1% by mass, sufficient emulsion stability cannot be obtained, and if it exceeds 4.0% by mass, stickiness may occur.

[0029] Patent document 1 is an invention that improves emulsion stability by combining oleic acid and / or isostearic acid in a system where potassium 4-methoxysalicylate as a salicylic acid derivative and an organic modified clay mineral coexist. Patent document 1 records that on the basis of liquid fatty acids such as isostearic acid, an emulsifier with low HLB (below 7) can also be combined (paragraph 0024), and the example of the low HLB emulsifier also includes sorbitan fatty acid ester. However, if the salicylic acid derivative in the system of patent document 1 is replaced with salicylic acid and then combined with a colorant, even if isostearic acid is combined, the viscosity change over time can be seen. For the first time, it was found that in a system where salicylic acid, an organic modified clay mineral and a colorant coexist, by combining sorbitan fatty acid ester, a composition that does not contain liquid fatty acids and does not cause viscosity changes over time and is extremely stable can be obtained. Therefore, the composition of the present invention includes a method that does not contain liquid fatty acids such as isostearic acid and oleic acid.

[0030] (d) Pigment

[0031] As the coloring material to be added to the composition of the present invention, those commonly added to color cosmetics, such as pigments and pearlescent pigments, can be used.

[0032] Specifically, it can be selected from inorganic white pigments (titanium dioxide, zinc oxide), inorganic red pigments (iron oxide (red iron oxide), iron titanate), inorganic brown pigments (γ-iron oxide), inorganic yellow pigments (yellow iron oxide, loess), inorganic black pigments (black iron oxide, carbon, low-order titanium oxide), inorganic purple pigments (mango purple, cobalt purple), inorganic green pigments (chromium oxide, chromium hydroxide, cobalt titanate), inorganic blue pigments (ultramarine, Prussian blue), pearlescent pigments (titanium oxide covered mica, titanium oxide covered bismuth oxychloride, titanium oxide covered talc, colored titanium oxide covered mica, bismuth oxychloride, fish scale foil), metal powder pigments (aluminum powder, copper powder), organic pigments (red 202, red 205, red 22 0, Red 228, Red 405, Orange 203, Orange 204, Yellow 205, Yellow 401, Blue 404), organic pigments of zirconium, barium, and aluminum lakes (Red 3, Red 104, Red 227, Red 401, Orange 205, Yellow 4, Yellow 202, Green 3, Blue 1), natural pigments (chlorophyll, carotenoids (β-carotene), safflower, carmine, chalcone, turmeric, betanin, flavonol, flavonoid, anthocyanin, anthraquinone, naphthoquinone), and functional pigments (boron nitride, photosensitizing pigment, synthetic fluorphlogopite, synthetic fluorphlogopite containing iron, and fine-grained composite powder (mixed fine powder)), but are not limited to these.

[0033] Powdered colorants such as pigments may be used in an untreated state or in a state surface-treated state with an organosilane compound, an organosilicon compound, a fluorine compound, a silane coupling agent, a fluorine resin, a fatty acid, a fatty acid soap, lauroyl lysine or the like.

[0034] As long as the composition of the present invention contains more than 0.1% by mass of colorant relative to the total amount of the composition, the effect of the present invention such as preventing uneven stripe color can be exerted. Therefore, the amount of the colorant in the composition of the present invention can be set to more than 0.1% by mass. In particular, when the composition of the present invention is used as a makeup cosmetic, the amount of the colorant is preferably set to more than 1.0% by mass, more preferably more than 5.0% by mass, and further preferably more than 10% by mass. When the amount is less than 1.0% by mass, a sufficient makeup effect cannot be obtained. The upper limit of the amount of the colorant is not particularly limited, and is generally less than 40% by mass, preferably less than 30% by mass. When more than 40% by mass is combined, there is a situation where stability is reduced.

[0035] The composition of the present invention is a water-in-oil emulsion composition and therefore contains oil constituting the external phase of the emulsion and water constituting the internal phase.

[0036] The oil component constituting the external phase is not particularly limited as long as it can be used in cosmetics, etc., and preferably contains silicone oil. As the silicone oil, volatile silicone oil is particularly preferably used, and volatile linear silicone oil (1.5cs, 2cs, etc.) is particularly preferred. The amount of the oil component in the composition of the present invention is about 1 to 30% by mass.

[0037] The water constituting the internal phase can hold hydrophilic components such as alcohol (ethanol) etc. The amount of water in the composition of the present invention is about 20 to 40% by mass.

[0038] The composition of the present invention may contain, in addition to the essential components (a) to (d), oil and water, any other components generally used in cosmetics, pharmaceuticals and the like, within the range not impairing the effects of the present invention.

[0039] For example, the composition of the present invention may be blended with polyether-modified silicone to further improve the slurry release stability.

[0040] Preferred for use in the present invention is a polyether-modified silicone having a polyoxyalkylene group grafted onto a polysiloxane skeleton, which may be arbitrarily co-modified with an alkyl group. A polyether-modified silicone having a linear polysiloxane skeleton (linear type) and a polyether-modified silicone having a branched polysiloxane skeleton (branched type) may be used, and from the viewpoint of improving stability, a branched polyether-modified silicone is preferred. In addition, although not particularly limited, it is preferred to use a polyether-modified silicone having an HLB of preferably 6.0 or less, more preferably 5.0 or less and preferably 3.0 or more, and a polyether-modified silicone that has not been co-modified with an alkyl group.

[0041] Specific examples of polyether-modified silicone include PEG-3 polydimethylsiloxane, PEG-10 polydimethylsiloxane, cetyl PEG / PPG-10 / 1 polydimethylsiloxane (the above are linear types), PEG-9 polydimethylsiloxyethyl polydimethylsiloxane (the above are branched types), etc. Among these, PEG-9 polydimethylsiloxyethyl polydimethylsiloxane is particularly preferred.

[0042] When a polyether-modified silicone is added, its amount is preferably 0.1 to 5% by mass, more preferably 1 to 4% by mass, and particularly preferably 2 to 3% by mass relative to the total amount of the composition. When it is less than 0.1% by mass, the stabilization improvement effect cannot be obtained, and when it exceeds 5% by mass, streaky color unevenness may occur.

[0043] If polyethylene glycol is added to the composition of the present invention, the effect of stably retaining salicylic acid is further improved.

[0044] The polyethylene glycol preferably used in the present invention is a polyethylene glycol having an average molecular weight of 1000 to 15000. Specific examples include polyethylene glycol 1000 (INCI name: PEG-20), polyethylene glycol 1500 (INCI name: PEG-6; PEG-32), polyethylene glycol 4000 (INCI name: PEG-75), polyethylene glycol 6000 (INCI name: PEG-150), and polyethylene glycol 11000 (INCI name: PEG-240). Among these, polyethylene glycol-6000 is preferred.

[0045] The amount of polyethylene glycol blended is preferably 1 to 8% by mass, more preferably 2 to 7% by mass, and particularly preferably 3 to 6% by mass, based on the total amount of the composition.

[0046] Examples of other optional components include moisturizers, ultraviolet absorbers, ultraviolet scatterers, buffers, chelating agents, preservatives, fragrances, and various drugs, but the components are not limited to these examples.

[0047] The water-in-oil emulsion composition of the present invention can be prepared by conventional methods, and the emulsification method is not particularly limited. For example, the following method can be cited: the separately prepared water phase (internal phase) and oil phase (external phase) are heated to about 80° C., the heated water phase is slowly added to the oil phase, emulsified with an emulsifier, and then naturally cooled to room temperature.

[0048] Since the composition of the present invention contains salicylic acid at a higher concentration than in the past, the anti-acne effect based on salicylic acid can be fully exerted. In addition, a coloring material such as a pigment can be added without causing streaky color unevenness, thereby exerting an excellent makeup effect. Therefore, the composition of the present invention is particularly suitable for providing as a makeup cosmetic.

[0049] Example

[0050] The present invention will be described in more detail below with reference to examples, but the technical scope of the present invention is not limited to these examples.

[0051] According to conventional methods, color cosmetics with the formulations shown in Table 1 below were prepared.

[0052] The cosmetic of each example was evaluated for separation stability, stripe color unevenness, and usability (immediately after preparation and 2 weeks after preparation) according to the following methods and criteria.

[0053] (1) Separation stability

[0054] The cosmetic of each example was left to stand at 50° C. for 4 weeks, and then the presence or absence of sludge (floating oil) was visually observed and evaluated based on the following criteria.

[0055] (Evaluation Criteria)

[0056] A: No change (no separation)

[0057] B: A slightly transparent liquid is confirmed on the surface

[0058] C: Confirmed by transparent liquid retention

[0059] (2) Uneven stripe color

[0060] The cosmetic mass of each example stored in a polyethylene container was visually observed and evaluated based on the following criteria.

[0061] (Evaluation Criteria)

[0062] A: No streaky color unevenness

[0063] B: There is a faint strip of color unevenness in a narrow range, but the overall appearance is fine

[0064] C: There is a faint strip of color unevenness over a wide area

[0065] (3) Usability

[0066] The usability of the cosmetic of each example was evaluated by a professional panel based on the following criteria immediately after preparation (immediately) and after being left to stand at room temperature for 2 weeks (over time).

[0067] (Evaluation Criteria)

[0068] A: Extended light

[0069] B: Slightly thicker

[0070] C: Very heavy extension

[0071] [Table 1]

[0072]

[0073] As shown in Table 1, the cosmetics of Example 1, which is an oil-in-water emulsion composition containing (a) salicylic acid, (b) an organically modified clay mineral, (c) sorbitan fatty acid ester, and (d) a colorant, are excellent in terms of separation stability, do not produce streaky color unevenness, and do not change in usability over time. On the other hand, the viscosity of Comparative Example 1, in which sorbitan fatty acid ester is replaced by isostearic acid, increases over time and is slightly thick in usability. Comparative Example 2, in which neither sorbitan fatty acid ester nor isostearic acid is formulated, is thick in usability immediately after preparation and produces some streaky color unevenness. Although the usability of Comparative Example 3, in which salicylic acid is removed from Comparative Example 2, is slightly improved, the streaky color unevenness cannot be suppressed. In addition, Comparative Example 4, in which salicylic acid in Example 1 is replaced by 4-methoxysalicylic acid, increases in viscosity over time, is slightly thick in usability, and produces significant streaky color unevenness. The above results demonstrate that by blending all of the essential components (a) to (d) of the present invention, not only the slurry separation stability but also the unevenness of the stripe color and the change in usability (viscosity increase) can be suppressed.

Claims

1. A water-in-oil emulsion composition having an anti-acne effect, characterized in that: contain: (a) 0.5 mass % or more of salicylic acid; (b) organically modified clay minerals; (c) 0.1 to 4.0 mass % of sorbitan fatty acid ester; and (d) 0.1% by mass or more and 40% by mass or less of a coloring material.

2. The composition according to claim 1, wherein The blending amount of the (b) organically modified clay mineral is 0.1 to 5.0% by mass based on the total amount of the composition.

3. The composition according to claim 1 or 2, further comprising a polyether-modified silicone. The composition according to claim 1 or 2, further comprising polyethylene glycol.

5. The composition according to claim 1 or 2, wherein The (c) sorbitan fatty acid ester is sorbitan sesquiisostearate. The composition according to claim 1 or 2, further comprising ethanol.

7. A color cosmetic comprising the composition according to any one of claims 1 to 6, wherein the amount of the colorant (d) is 1.0% by mass or more.

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