Water-in-oil type sunscreen cosmetic

Abstract

To provide oil-in-water sunscreen cosmetics that have a high UV protection effect, a good feeling of use with moisture and with no squeakiness, and high formulation stability.SOLUTION: Oil-in-water sunscreen cosmetics contain (A) hydrophobic metal oxide, and (B) a component represented by the following formula (1). The component (B) is preferably bis-ethylhexyl bis-oleyl pyromellitamide. The cosmetics preferably further contain (C) a polymer composed of 2-acrylamide-2-methyl sulfonic acid and / or a salt thereof (e.g. (ammonium acryloyldimethyltaurate / VP) copolymer).SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a water-in-oil sunscreen cosmetic, and more particularly to a sunscreen cosmetic having a high ultraviolet ray protection effect, no squeaking feeling, a moist feeling, and excellent stability over time.

Background Art

[0002] In sunscreen cosmetics that protect against ultraviolet rays, ultraviolet absorbers and ultraviolet scattering agents are blended in order to block ultraviolet ray irradiation to the skin and obtain a high SPF (Sun Protection Factor) value. As dosage forms of sunscreen cosmetics, there are water-in-oil sunscreen cosmetics and water-in-oil sunscreen cosmetics. However, since water-in-oil sunscreen cosmetics are sticky and have an oily feeling, in recent years, there has been a demand for water-in-oil sunscreen cosmetics with less stickiness and oiliness and a good feeling in use.

[0003] Sunscreen cosmetics are required to have a good touch and stability as well as a high ultraviolet ray protection effect. It is very difficult to achieve a high ultraviolet ray protection effect while maintaining these. In particular, water-in-oil sunscreen cosmetics are likely to have a non-uniform coating film, and it is very difficult to enhance the ultraviolet ray protection effect.

[0004] In order to enhance the ultraviolet ray protection effect, it is known to blend an ultraviolet absorber or an ultraviolet scattering agent. However, in particular, although ultraviolet scattering agents cause less skin irritation, the whiteness and the specific squeaking feeling during application may be a problem. In particular, water-in-oil emulsified cosmetics are likely to feel the squeaking feeling caused by the ultraviolet scattering agent because the amount of oil blended is less than that of water-in-oil emulsified cosmetics, and this has been a particularly big problem.

[0005] Developing a high SPF without a high content of such a UV scattering agent with a bad feel is a technology highly demanded from the viewpoints of feel and skin irritation. In Patent Document 1, an improvement in the SPF value by blending an alkyl silicone wax having a melting point of 60°C or higher has been reported. Also, in Patent Document 2, an improvement in the SPF value by blending a nonpolar wax having a melting point of 30°C or higher and a melting enthalpy of less than 250 J / g has been reported. However, when these alkyl silicone waxes or nonpolar waxes are used, the feel of use tends to become heavy, and furthermore, there is a problem in terms of feel because the squeak and stickiness of the UV scattering agent and the UV absorber cannot be suppressed. As another example of improving the SPF value, for example, in Patent Document 3, a method using crystalline cellulose with a fiber width of less than 10 nm has been reported. However, there is no mention of the feel of use or stability. Sunscreens with a high content of UV scattering agents and UV absorbers have worse stability and feel of use than ordinary emulsion compositions, so the results in this regard are not sufficient. In Patent Document 4, an improvement in SPF by blending dextrin fatty acid ester as a thickener has been reported. However, when dextrin fatty acid ester is used as a thickener, there are problems such as poor stability and feel of use. Also, in Patent Document 5, an oil-based cosmetic using a compound represented by the following formula (2) [Chemical formula] (In the formula, R 1 is a group obtained by removing n hydrogen atoms from the structural formula of benzene, benzophenone, biphenyl, naphthalene, cyclohexane, or butane, and R 2 is an aliphatic hydrocarbon group having 4 or more carbon atoms. n represents an integer of 3 or more. The n R 2 may be the same or different) has been reported. However, the effect on improving the SPF value and reducing the squeakiness when this compound is blended in an oil-in-water type sunscreen cosmetic has not been known. From the above, it has been an urgent task to develop a technology that can achieve a high SPF without impairing the feel of use and stability.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0007] The present invention has been made in view of the above prior art, and an object thereof is to provide an oil-in-water type sunscreen cosmetic having a high ultraviolet ray protection effect, no scratchy feeling, a good feeling of use with a moist feeling, and high formulation stability.

Means for Solving the Problems

[0008] As a result of intensive studies by the present inventors to achieve the above object, the following components (A) and (B) (A) Hydrophobically treated metal oxide (B) is represented by the following formula (1).

Chemical Formula

Effects of the Invention

[0009] According to the present invention, it is possible to provide an oil-in-water type sunscreen cosmetic that has a high ultraviolet ray protection effect, a moist feeling, no squeaking feeling, and high formulation stability.

Best Mode for Carrying Out the Invention

[0010] Hereinafter, the present invention will be described in more detail. Unless otherwise noted, when the blending amount of a component is expressed as “%” below, it means mass%.

[0011] The component (A) hydrophobically treated metal oxide blended in the present invention is one in which the surface of the metal oxide is hydrophobically treated. The type of the metal oxide is not particularly limited as long as it is within the range usually used in cosmetics, but particularly fine particle metal oxides such as titanium oxide, zinc oxide, zirconium oxide, and cerium oxide are preferable. The method of the hydrophobization treatment is not particularly limited, but specifically, a method of coating the surface of the metal oxide with an organic compound such as fatty acid metal soap, silicone, triethoxycaprylylsilane, hydrogen dimethicone, dimethicone, isostearic acid, and stearic acid is preferable. Inorganic compounds such as silica and alumina may be coated simultaneously with the hydrophobization treatment. Among them, triethoxycaprylylsilane and hydrogen dimethicone are preferable as the surface treatment agents from the viewpoints of ultraviolet ray protection effect and squeaking feeling.

[0012] The component (A) used in the present invention is appropriately selected for the purpose of obtaining a desired ultraviolet ray protection effect, and may be used alone or in combination of two or more. For example, when it is desired to exhibit an excellent ultraviolet ray protection effect in a wide wavelength range from UVA to UVB, it is preferable to blend at least one kind each of a metal oxide having a high scattering effect in the UVA region and a metal oxide excellent in scattering in the UVB region in combination. It is also possible to use an ultraviolet absorber in combination with the ultraviolet scattering agent.

[0013] The blending amount of component (A) varies depending on the desired UV protection effect. For example, it is 3% or more, more preferably 5 - 40%, and even more preferably 7 - 35% in the cosmetic. Within this range, a certain UV protection effect can be expected.

[0014] As described in formula (1), component (B) used in the present invention has four amide bonds in the monomer molecule, and further has an aliphatic hydrocarbon group (R2, R3) with 6 or more carbon atoms via the amide bond. Component (B) has the property that monomers of component (B) self-associate through hydrogen bonds at the amide bond site to form a fibrous self-assembled structure. Furthermore, since the hydrophobic groups R2 and R3 have an affinity for the oily component, by being compatible with the liquid oil, a composition containing the liquid oil or paste-like oily component can be thickened and gelled.

[0015] As a specific commercially available example of component (B), bis(2-ethylhexyl)bis(oleyl)pyromellitamide of "Cellmolys (registered trademark) SB03" manufactured by Daicel Corporation is preferable.

[0016] The blending amount of component (B) is not particularly limited, but 0.005% - 2.0% as a pure component in the cosmetic is desirable. More preferably, it is 0.01 - 1.5%. Within this range, a high UV protection effect, a good feeling in use without stickiness or astringency, and very excellent high formulation stability are achieved.

[0017] Component (C) used in the present invention is Acryloyldimethyltaurine(It is a polymer having (also referred to as AMPS) and / or its salt as a constituent component. Component (C) may be a homopolymer or a copolymer. Specifically, (HEA / sodium acryloyldimethyltaurate / stearyl methacrylate-20) copolymer, (acrylamide / sodium acryloyldimethyltaurate) copolymer, (acrylamide / sodium acryloyldimethyltaurate / acrylic acid) copolymer, (sodium acrylate / acryloyldimethyltaurine) copolymer, (sodium acrylate / acryloyldimethyltaurine / dimethylacrylamide) cross-polymer, (sodium acrylate / sodium acryloyldimethyltaurate) copolymer, (sodium acrylate / sodium acryloyldimethyltaurate / acrylamide) copolymer, (hydroxyethyl acrylate / sodium acryloyldimethyltaurine) copolymer Na, (hydroxyethyl acrylate / sodium acryloyldimethyltaurate) copolymer, (sodium acryloyldimethyltaurate / VP) cross-polymer, (sodium acryloyldimethyltaurate / PEG-8 diacrylate) cross-polymer, (sodium acryloyldimethyltaurate / lauryl methacrylamide) copolymer, (ammonium acryloyldimethyltaurate / VP) copolymer, (ammonium acryloyldimethyltaurate / ammonium carboxyethyl acrylate) cross-polymer, (ammonium acryloyldimethyltaurate / stearyl methacrylate-25) cross-polymer, (ammonium acryloyldimethyltaurate / stearyl methacrylate-8) copolymer, (ammonium acryloyldimethyltaurate / behenyl methacrylate-25) cross-polymer, (ammonium acryloyldimethyltaurate / lauryl methacrylate-7) copolymer, (dimethylacrylamide / sodium acryloyldimethyltaurate) cross-polymer, sodium polyacryloyldimethyltaurate, etc. are mentioned. Particularly preferred are (hydroxyethyl acrylate / sodium acryloyldimethyltaurate) copolymer, (sodium acrylate / sodium acryloyldimethyltaurate) copolymer, (ammonium acryloyldimethyltaurate / VP) copolymer, and these have better moist feeling and improved stability.

[0018] The blending amount of component (C) is not particularly limited, but it is preferably 0.01% to 2.5% as a pure component in the cosmetic. More preferably, it is 0.1 to 2.0%. Within this range, the feeling of moistness and stability are more excellent.

[0019] In the water-in-oil type sunscreen cosmetic of the present invention, in addition to the above essential components, it is also possible to blend components generally used in cosmetics etc. as necessary. For example, ultraviolet absorbers, pearlescent agents, moisturizers, polymers other than component (C), fragrances, bactericides, preservatives, antioxidants, pH adjusters, chelating agents, anti-inflammatory agents, antioxidants, cooling agents, herbal extracts, additives such as vitamins, etc. can be blended at appropriate times. The blending ratio when containing these components can be appropriately selected according to the type and purpose, and one kind can be used alone, or two or more kinds can be used in appropriate combination.

Examples

[0020] The present invention will be further described with examples below. Note that these examples do not limit the present invention in any way.

[0021] <SPF Measurement Method> For the substrate HELIOPLATE HD6 (manufactured by HelioScreen), the cosmetic of each example was uniformly applied so as to be 1.3 mg / cm 2 and dried at room temperature for 30 minutes. The SPF value was measured at 9 locations with an SPF analyzer UV-2000S (manufactured by Labsphere).

[0022] <Evaluation of SPF Improvement Effect> As the evaluation of the SPF value, it was evaluated according to the following criteria with respect to the predetermined comparative examples of each agent. Specifically, Examples 1 to 11, Comparative Examples 2 to 4 used Comparative Example 1, Example 12 used Comparative Example 5, and Comparative Example 6 used Comparative Example 7 as the criteria for the SPF improvement effect, and the SPF with respect to the criteria was calculated using the following formula. ◎: With respect to the SPF value of the comparative example, the SPF value of the example is 130% or more ○: The SPF value of the example is 120% or more and less than 130% of the SPF value of the comparative example △: The SPF value of the example is 100% or more and less than 120% of the SPF value of the comparative example ×: The SPF value of the example is less than 100% of the SPF value of the comparative example

[0023]

Number

[0024] Regarding stability, evaluation was conducted on the following items. <Stability (Separation)> The prepared preparation is allowed to stand at 40 °C for 2 weeks, and the state (separation) after 2 weeks is visually confirmed. ◎: No separation occurs at all. ○: No separation occurs, but deterioration of the emulsified state is observed to such an extent that there is no problem with product quality. △: It is difficult to distinguish with the naked eye, but separation occurs to such an extent that it can be observed with a magnifying glass. ×: Separation occurs in a conspicuous state, which is not preferable in terms of product quality.

[0025] <Sensory Property Evaluation Test A: Scratchy Feeling> In the sensory property evaluation test, regarding the touch (scratchy feeling) when the evaluation sample is applied to the face, 10 professional judges assigned evaluation points to each sample of the examples and comparative examples according to the following evaluation criteria. The lower the evaluation score for those who feel the scratchy feeling more, and according to the average score, 4.0 or more was rated as ◎, 3.0 or more and less than 4.0 as ○, 2.0 or more and less than 3.0 as △, and less than 2.0 as ×.

[0026] [Evaluation Criteria] 5: There is no scratchy feeling at all, which is very preferable. 4: There is no scratchy feeling, which is preferable. 3: It cannot be said either way. 2: A scratchy feeling is felt, which is not preferable. 1: There is a very strong scratchy feeling, which is not preferable.

[0027] <Sensory property evaluation test B: Moist feeling> In the sensory property evaluation test, regarding the texture (moist feeling) when the evaluation sample was applied to the face, 10 professional judges gave higher evaluation scores to those who felt a more moist feeling according to the following evaluation criteria, and assigned evaluation scores to the samples of each of the examples and comparative examples. According to the average score, 4.0 or more was rated as ◎, 3.0 or more and less than 4.0 was rated as ○, 2.0 or more and less than 3.0 was rated as △, and less than 2.0 was rated as ×.

[0028] [Evaluation criteria] 5: There is a very large amount of moist feeling, which is preferable. 4: There is a large amount of moist feeling, which is preferable. 3: It cannot be said either way. 2: There is a small amount of moist feeling, which is not preferable. 1: There is a very small amount of moist feeling, which is not preferable.

[0029]

Table 1

[0030]

Table 2

[0031]

Table 3

[0032]

Table 4

[0033] As shown in Table 1 and Table 2, since the SPF fluctuates greatly when the blending amount of Component A changes, in Examples 1 to 11 and Comparative Examples 1 to 4, the blending amount of Component A was unified for evaluation. The measured value of Comparative Example 1 was used as the reference for the comparison of SPF for evaluation. Comparing Example 1 with Comparative Example 1, the SPF value is 132% due to the presence or absence of Component B. Looking at Component B' (Comparative Examples 2, 3, and 4), which is a material that thickens oils similar to Component B, the effect of improving SPF is poor, and it can be seen that the evaluations of the scratchy feeling and moist feeling are also bad. Furthermore, comparing Example 2 with Comparative Examples 2, 3, and 4, the SPF improvement effect of Example 2 is 136% compared to Comparative Example 1, while that of Comparative Example 2 is 88%, Comparative Example 3 is 112%, and Comparative Example 4 is 104%. It can be seen that Example 2 containing Component C has a more excellent SPF improvement effect. Also, it can be seen that the same effect is exhibited when looking at Examples 10 and 11 where the surface treatment of Component A is changed. Comparative Example 5 and Example 12 shown in Table 3 evaluated the case where the blending amount of Component A was changed. Looking at the results, it can be clearly seen that there are differences in the SPF improvement effect, scratchy feeling, and moist feeling effects. Comparative Examples 6 and 7 in Table 4 are examples using hydrophilic-treated titanium oxide. Also in this case, since the ultraviolet light protecting agent is changed, a new standard was set as Comparative Example 6 for evaluation. Looking at the results, in the case of metal oxides that have not been hydrophobized, even if there is Component (B), the problems of the present application could not be achieved. From these results, it can be seen that Component (A) is effective when hydrophobized. From the above results, it is also suggested that the configuration of the present application has great inventiveness. For the invention of the configuration of the present application, in addition to the effect of enhancing the ultraviolet light protection effect, it has been found that it can simultaneously impart suppression of the scratchy feeling caused by the ultraviolet light protecting agent, impart the moist feeling necessary for skin care, and good stability.

[0034] Using a conventional method, sunscreen cosmetics of each formulation were prepared. It was confirmed that the effects of the present invention were achieved in any of the formulations.

[0035] Formulation 1: Sunscreen emulsion Blending components Blending amount (%) Isostearic acid-treated zinc oxide 13 Hydrogenated polyisobutene 15 Polyhydroxystearic acid 1 Isodecyl neopentanoate 2 Bis(ethylhexyl)bis(oleyl)pyromellitamide 0.3 Dimethicone 1 Sorbitan sesquiisostearate 0.8 PEG - 60 glyceryl isostearate 1 1,3 - Butylene glycol 10 Xanthan gum 0.1 Hydroxypropyl methylcellulose stearoxy ether 0.05 Silkworm polysaccharide 0.02 Sodium acrylate·Sodium acryloyldimethyl taurate Copolymer / Isohexadecane / Polysorbate 80 0.5 Preservative appropriate amount Stabilizer appropriate amount Purified water remainder Total 100

[0036] Formulation 2: Sunscreen cream Ingredient Dosage (%) Dimethicone - treated zinc oxide 18 Dimethicone - treated titanium dioxide 6 Hydrogenated polyisobutene 5 Polyhydroxystearic acid 2 Cyclopentasiloxane 15 Cetyl alcohol 3 Glyceryl stearate 2.5 Bis - ethylhexyl bis - oleyl pyromellitamide 0.3 Dimethicone 1 Sorbitan sesquiisostearate 0.8 PEG - 60 glyceryl isostearate 1 1,3 - Butylene glycol 10 Xanthan gum 0.2 Hydroxypropyl methylcellulose stearoxy ether 0.05 Silkworm polysaccharide 0.02 Sodium acrylate·Sodium acryloyldimethyl taurate Copolymer / Isohexadecane / Polysorbate 80 1.5 Preservative appropriate amount Stabilizer appropriate amount Purified water residue Total 100

[0037] Prescription 3: Foundation Blending components Blending amount (%) Zinc oxide treated with stearic acid 10 Titanium oxide treated with stearic acid 10 Polyhydroxystearic acid 1 Iron oxide 0.3 Methylphenylpolysiloxane 2 Dimethicone 1 Bis(2-ethylhexyl)bis(oleoyl)pyromellitamide 0.2 Tridecyl isononanoate 8 Sucrose stearate 0.7 Sodium N-stearoylglutamate 0.2 Hydrogenated lecithin 0.3 1,3-Butylene glycol 10 Xanthan gum 0.1 Sodium acrylate / sodium acryloyldimethyltaurate copolymer 1.5 Copolymer / isohexadecane / polysorbate 80 Preservative Appropriate amount Stabilizer Appropriate amount Purified water residue Total 100

Claims

1. (A) Hydrophobically treated metal oxide (B) Bis(2-ethylhexyl)bis(oleoyl)pyromellitamide An oil-in-water type sunscreen cosmetic containing the same.

2. The oil-in-water type sunscreen cosmetic according to Claim 1, wherein the hydrophobic treatment of the component (A) contains one or more selected from triethoxycaprylylsilane, isostearic acid, hydrogen dimethicone, and dimethicone.

3. The oil-in-water type sunscreen cosmetic according to any one of Claims 1 to 2, containing a polymer having acryloyldimethyltaurine acid and / or its salt as a constituent component.

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