SOLID COSMETIC COMPOSITION FOR BLOCKING ULTRAVIOLET RADIATION HAVING WATER RESISTANCE AND CLEANSING PROPERTIES

Abstract

The present invention provides a solid cosmetic composition which contains a UV-blocking agent, a fatty acid, and a wax, has excellent water resistance and/or cleansing properties, and can effectively block ultraviolet radiation. More specifically, a cosmetic composition for blocking ultraviolet radiation according to the present invention has excellent water resistance at low pH, and is converted to having excellent cleansing properties at high pH during the cleansing of skin, and thus can be effectively used.

Claims

1. A cosmetic composition for blocking ultraviolet radiation comprising a UV-blocking agent, a fatty acid, an oil, and a wax, wherein the fatty acid is 5 to 40% by weight based on the total weight of the composition, and the composition is solid.

2. The cosmetic composition according to claim 1, wherein the composition does not substantially contain water.

3. The cosmetic composition according to claim 1, wherein the wax is 5 to 40% by weight based on the total weight of the composition.

4. (canceled)

5. The cosmetic composition according to claim 1, wherein the fatty acid is comprised in a weight greater than 1 to less than 5 times the weight of the wax.

6. (canceled)

7. The cosmetic composition according to claim 1, wherein the fatty acid is myristic acid, palmitic acid, stearic acid, isostearic acid, behenic acid, or a mixture thereof.

8. The cosmetic composition according to claim 7, wherein the fatty acid is isostearic acid.

9. The cosmetic composition according to claim 1, wherein the liquid fatty acid among the fatty acids is comprised in a weight greater than 1 to less than 100 times the weight of the solid fatty acid.

10. The cosmetic composition according to claim 1, wherein the UV-blocking agent is 10 to 40% by weight based on the total weight of the composition.

11. The cosmetic composition according to claim 1, wherein the oil is 5 to 55% by weight based on the total weight of the composition.

12. The cosmetic composition according to claim 1, comprising based on the total weight of the composition, 10 to 40% by weight of UV-blocking agent which is ethylhexylmethoxycinnamate, octocrylene, ethylhexylsalicylate, bis-ethylhexyloxyphenolmethoxyphenyltriazine, diethylaminohydroxybenzoylhexylbenzoate, or mixtures thereof; 5 to 40% by weight of fatty acid which is myristic acid, palmitic acid, stearic acid, isostearic acid, behenic acid, or mixtures thereof; 5 to 40% by weight of wax which is polyethylene, ethylene/propylene copolymer, synthetic wax, or a mixture thereof; 5 to 55% by weight of oil which is triethylhexanoin, hexyllaurate, or a mixture thereof; and optionally 5 to 30% by weight of polymethylsilsesquioxane, wherein the composition is solid, and the composition is not dispersed at pH 7 and dispersed in an aqueous solution of pH 9 to 14.

13. (canceled)

14. A method of blocking ultraviolet radiation in a subject while attaining water resistance and cleansing properties, comprising: applying a stick type cosmetic composition for blocking ultraviolet radiation to skin of the subject, wherein the stick type cosmetic composition comprises a UV-blocking agent, a fatty acid, an oil, and a wax, and wherein the fatty acid is present in an amount of 5 to 40% by weight based on a total weight of the stick type cosmetic composition.

15. The method according to claim 14, wherein the stick type cosmetic composition does not substantially contain water.

16. The method according to claim 14, wherein the wax is 5 to 40% by weight based on the total weight of the stick type cosmetic composition.

17. The method according to claim 14, wherein the fatty acid is comprised in a weight greater than 1 to less than 5 times the weight of the wax in the stick type cosmetic composition.

18. The method according to claim 14, wherein the fatty acid is myristic acid, palmitic acid, stearic acid, isostearic acid, behenic acid, or a mixture thereof.

19. The method according to claim 18, wherein the fatty acid is isostearic acid.

20. The method according to claim 14, wherein the liquid fatty acid among the fatty acids is comprised in a weight greater than 1 to less than 100 times the weight of the solid fatty acid in the stick type cosmetic composition.

21. The method according to claim 14, wherein the UV-blocking agent is 10 to 40% by weight based on the total weight of the stick type cosmetic composition.

22. The method according to claim 14, wherein the oil is 5 to 55% by weight based on the total weight of the stick type cosmetic composition.

23. The method according to claim 14, wherein the stick type cosmetic composition comprises, based on the total weight of the stick type cosmetic composition, 10 to 40% by weight of UV-blocking agent which is ethylhexylmethoxycinnamate, octocrylene, ethylhexylsalicylate, bis-ethylhexyloxyphenolmethoxyphenyltriazine, diethylaminohydroxybenzoylhexylbenzoate, or mixtures thereof; 5 to 40% by weight of fatty acid which is myristic acid, palmitic acid, stearic acid, isostearic acid, behenic acid, or mixtures thereof; 5 to 40% by weight of wax which is polyethylene, ethylene/propylene copolymer, synthetic wax, or a mixture thereof; 5 to 55% by weight of oil which is triethylhexanoin, hexyllaurate, or a mixture thereof; and optionally 5 to 30% by weight of polymethylsilsesquioxane, wherein the composition is solid, and the composition is not dispersed at pH 7 and dispersed in an aqueous solution of pH 9 to 14.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0055] FIG. 1 shows the results of dispersion experiments of Comparative Example 1 and Example 14.

[0056] FIG. 2 shows the results of dispersion experiments of Comparative Example 1 and Examples 1 to 10.

[0057] FIG. 3 is a graph showing the cutting hardness measurement results of Examples 11 to 15.

[0058] FIG. 4 is a graph showing the melting point measurement results of Examples 11 to 15.

MODE FOR INVENTION

[0059] Hereinafter, examples and the like will be described in detail to aid understanding of the present invention. However, the examples according to the present invention can be modified in many different forms, and the scope of the present invention should not be construed as being limited to the following examples. Examples of the present invention are provided to more completely explain the present invention to those skilled in the art.

Example 1. Preparation of Comparative Example and Examples According to the Content of Fatty Acids

[0060] A stick-type sunscreen was prepared according to the prescription shown in Table 1 below. According to the prescription shown in Table 1, all raw materials were mixed, heated to 90° C., mixed well until completely dissolved, and then put in a stick-type container and cooled to room temperature.

TABLE-US-00001 TABLE 1 Comparative Exam- Exam- Exam- Exam- Exam- Exam- Exam- Exam- Exam- Exam- (Unit: wt %) example 1 ple 1 ple 2 ple 3 ple 4 ple 5 ple 6 ple 7 ple 8 ple 9 ple 10 Stearic Acid 0.5 1.5 2.5 5 7.5 10 12.5 15 17.5 20 Palmitic Acid 0.5 1.5 2.5 5 7.5 10 12.5 15 17.5 20 Hexylaurate 42 41 39 37 32 27 22 17 12 7 2 Polyethylene wax 15 15 15 15 15 15 15 15 15 15 15 Synthetic wax 2.4 2.4 2.4 2.4 2.4 2.4 2.4 2.4 2.4 2.4 2.4 Ethylene/Propylene Copolymer 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 Bis-ethylhexyloxyphe- 2 2 2 2 2 2 2 2 2 2 2 nolmethoxyphenyltriazine Diethylaminohydroxybenzo- 2 2 2 2 2 2 2 2 2 2 2 ylhexylbenzoate Triethylhexanoin 8 8 8 8 8 8 8 8 8 8 8 Ethylhexylmethoxycinnamate 7 7 7 7 7 7 7 7 7 7 7 Ethylhexyl Salicylate 4 4 4 4 4 4 4 4 4 4 4 Octocrylene 7 7 7 7 7 7 7 7 7 7 7 Polymethylsilsesquioxane 10 10 10 10 10 10 10 10 10 10 10 Total 100 100 100 100 100 100 100 100 100 100 100

[0061] In Table 1, PERFORMALENE 400™, a trade name of New Phase Technologies, was used as the polyethylene wax. LIPWAX PZ80-20™ containing a specific wax and an ethylene/propylene copolymer in a weight ratio of 8:2, a trade name of JAPAN NATURAL PRODUCTS, was used as the synthetic wax and ethylene/propylene copolymer. SESQ-101™ from N&M TECH was used as polymethylsilsesquioxane. The same ingredients were used in other examples below.

Example 2. Preparation of Examples According to the Type of Fatty Acid

[0062] A stick-type sunscreen was prepared according to the prescription shown in Table 2 below. According to the prescription shown in Table 2, all raw materials were mixed, heated to 90° C., mixed well until completely dissolved, and then put in a stick-type container and cooled to room temperature.

TABLE-US-00002 TABLE 2 (Unit: wt %) Example 11 Example 12 Example 13 Example 14 Example 15 Myristic acid 15 Palmitic Acid 15 Stearic Acid 15 Isostearic Acid 15 Behenic Acid 15 Hexylaurate 27 27 27 27 27 Polyethylene wax 15 15 15 15 15 Synthetic wax 2.4 2.4 2.4 2.4 2.4 Ethylene/Propylene Copolymer 0.6 0.6 0.6 0.6 0.6 Bis- 2 2 2 2 2 ethylhexyloxyphenolmethoxyphenyltriazine Diethylaminohydroxybenzoylhexylbenzoate 2 2 2 2 2 Triethylhexanoin 8 8 8 8 8 Ethylhexylmethoxycinnamate 7 7 7 7 7 Ethylhexyl Salicylate 4 4 4 4 4 Octocrylene 7 7 7 7 7 Polymethylsilsesquioxane 10 10 10 10 10 Total 100 100 100 100 100

Example 3. Preparation of Examples According to the Content of Fatty Acids (Including Samples Wherein Solid Fatty Acids and Liquid Fatty Acids are Used Together)

[0063] A stick-type sunscreen was prepared according to the prescription shown in Table 3 below. According to the prescription shown in Table 3, all raw materials were mixed, heated to 90° C., mixed well until completely dissolved, and then cooled to room temperature in a stick-type container.

TABLE-US-00003 TABLE 3 Exam- Exam- Exam- Exam- Exam- Exam- Exam- Comparative Comparative (Unit: wt %) ple 16 ple 17 ple 18 ple 19 ple 20 ple 21 ple 22 example 2 example 3 Palmitic Acid 8 8 10 10 — — — 8 8 Stearic Acid 8 8 10 10 6 3 — 8 8 Isostearic Acid 4 8 4 8 15 18 21 8 8 Hexylaurate To 100 To 100 To 100 To 100 To 100 To 100 To 100 To 100 To 100 Polyethylene wax 16 16 16 16 16 16 16 — 3 Synthetic wax 2.4 2.4 2.4 2.4 2.4 2.4 2.4 — — Ethylene/Propylene Copolymer 0.6 0.6 0.6 0.6 0.6 0.6 0.6 — — Bis-ethylhexyloxyphe- 3 3 3 3 3 3 3 3 3 nolmethoxyphenyltriazine Diethylaminohydroxybenzo- 2 2 2 2 2 2 2 2 2 ylhexylbenzoate Triethylhexanoin 8 8 8 8 8 8 8 8 8 Ethylhexylmethoxycinnamate 7 7 7 7 7 7 7 7 7 Ethylhexyl Salicylate 4 4 4 4 4 4 4 4 4 Octocrylene 7 7 7 7 7 7 7 7 7 Polymethylsilsesquioxane 20 20 20 20 20 20 20 20 20 Total 100 100 100 100 100 100 100 100 100

Experimental Example 1. Evaluation of Dispersion Force (Dispersion Experiment)

[0064] The dispersion experiment was conducted by dispersing the solid sun stick in normal water having a pH of 7 and an aqueous solution of tromethamine having a pH of 10 and observing the degree of dispersion (FIG. 1, FIG. 2 and Table 4).

[0065] As a result, Comparative Example 1 was not dispersed in all of the aqueous solutions of pH 7 and 10, but all Examples were dispersed. The degree of dispersion was particularly excellent when the fatty acid content was high compared to the wax.

TABLE-US-00004 TABLE 4 pH 7 pH 10 Comparative example 1 X X Example 1 X Δ Example 2 X ◯ Example 3 X ◯ Example 4 X ◯ Example 5 X ◯ Example 6 X ⊚ Example 7 X ⊚ Example 8 X ⊚ Example 9 X ⊚ Example 10 X ⊚ Example 11 X ⊚ Example 12 X ⊚ Example 13 X ⊚ Example 14 X ⊚ Example 15 X ⊚ Example 16 X ⊚ Example 17 X ⊚ Example 18 X ⊚ Example 19 X ⊚ Example 20 X ⊚ Example 21 X ⊚ Example 22 X ⊚ X: It was not dispersed at all, and transparent water was observed. Δ: Slightly dispersed and the water turned slightly cloudy.

[0066] ◯: It is dispersed and the water turns cloudy.

[0067] ⊚: It is dispersed, the water turns cloudy, and a bubble layer is formed.

Experimental Example 2. Evaluation of Water Resistance

[0068] A water resistance test was conducted with the sun stick prepared according to the prescription in Table 1 above. After applying the sun stick to the PMMA plate with a thickness of 1.3 mg/cm.sup.2, it was dried for more than 15 minutes. The transmittance of the dried PMMA plate was measured using a spectrophotometer. The transmittance was measured every 1 nm for the wavelength in the range of 290 to 400 nm at three different positions of the PMMA plate. To evaluate water resistance, a round stainless steel container was properly filled with tap water, and the PMMA plate was fixed so that it was completely submerged in water. After leaving it for 30 minutes while stirring at 3000 rpm using a disper, the PMMA plate was taken out and dried for more than 30 minutes. The transmittance in the wavelength range of 290 to 400 nm was measured using a spectrophotometer again with the completely dried PMMA plate. The transmittance measured before and after immersion was converted into an in-vitro SPF value according to the formula below and compared. The water resistance ratio was calculated by dividing the SPF after immersion by the SPF before immersion. The results are summarized in Table 5 below.

[00001]$\mathrm{SPF}=\underset{290}{\overset{400}{.Math.}}{E}_{\lambda }{S}_{\lambda }/\underset{290}{\overset{400}{.Math.}}{E}_{\lambda }{S}_{\lambda }{T}_{\lambda }$

[0069] E.sub.λ: Erythemal action spectrum

[0070] S.sub.λ: Spectral irradiance (W/m.sup.2/nm)

[0071] T.sub.λ: Transmittance

[0072] As a result, it was confirmed that the sun sticks of Examples 1 to 10 containing fatty acids had a better water resistance ratio than the sun sticks (Comparative example 1) that did not contain fatty acids. Since fatty acids do not react with water with neutral pH and are hydrophobic, they do not affect the water resistance of the sun stick. Rather, fatty acids reacted with a small amount of divalent ions contained in water to generate insoluble sediment, resulting in better water resistance and a higher SPF after immersion due to the scattering effect of insoluble sediment.

TABLE-US-00005 TABLE 5 Water SPF before SPF after resistance immersion immersion ratio (%) Comparative  89.45 ± 10.04 19.7 ± 7.sup.  22.02 example 1 Example 1  77.05 ± 13.46  53.75 ± 34.31 69.76 Example 2 101.75 ± 30.53  55.57 ± 48.63 54.61 Example 3 120.05 ± 27.96 92.21 ± 93.4 76.81 Example 4 112.82 ± 13.78  91.25 ± 32.49 80.88 Example 5  94.98 ± 30.74 106.92 ± 104.7 112.57 Example 6  154.1 ± 56.96  291.57 ± 165.83 189.21 Example 7 47.97 ± 8.01 17.79 ± 2.52 37.09 Example 8  67.58 ± 15.91 26.54 ± 5.86 39.27 Example 9 28.08 ± 2.9  37.63 ± 2.28 134.01 Example 10 35.00 ± 2.29 101.58 ± 69.5  290.23

Experimental Example 3. Detergency Evaluation

[0073] The cleaning power was evaluated for the sun stick prepared with the prescription of Table 1 above. After applying each sun stick to a thickness of 1.3 mg/cm.sup.2 on a PMMA plate, the transmittance in the 290-400 nm region was measured using a spectrophotometer. The transmittance was measured at three different positions of the PMMA plate. After that, 0.2 g of a 20% dispersion of cleansing foam was placed on the PMMA plate and washed evenly for 20 seconds using an electric cleanser. After rinsing well with lukewarm water, it was completely dried for 30 minutes or more, and the transmittance was measured again using a spectrophotometer. The cleaning rate was calculated by the formula below. At this time, the value that transmits more ultraviolet rays than the control plate was replaced with the value of the control plate, and it was assumed that the cleaning rate is 100%. The results are shown in Table 6 below.

[00002]$\mathrm{Cleaning}\mathrm{rate}\left(\%\right)={.Math.}_{290}^{400}\frac{T_{\lambda }^{\mathrm{after}}-T_{\lambda }^{\mathrm{before}}}{T_{\lambda }^{\mathrm{control}}-T_{\lambda }^{\mathrm{before}}}\times 100$

[0074] T.sub.λ.sup.control: Transmittance of the control PMMA plate at a single wavelength

[0075] T.sub.λ.sup.before: Transmittance before cleaning at a single wavelength

[0076] T.sub.λ.sup.after: Transmittance after cleaning at a single wavelength

[0077] Examples 1 to 10 showed a higher cleaning rate than Comparative example 1. This is because when fatty acids meet soapy water with a high pH, a saponification reaction occurs which leads to amphoteric properties. Fatty acid not only acts as a surfactant, but also helps the oil film to be washed away by leaving the sunscreen oil film through a saponification reaction.

TABLE-US-00006 TABLE 6 Cleaning Improvement rate compared to rate (%) Comparative example 1 (%) Comparative example 1 64.56 — Example 1 70.50 9.20 Example 2 71.76 11.15 Example 3 80.08 24.04 Example 4 78.24 21.19 Example 5 83.62 29.52 Example 6 79.81 23.62 Example 7 89.34 38.38 Example 8 85.88 33.02 Example 9 83.41 29.20 Example 10 81.21 25.79

Experimental Example 4. Hardness and Melting Point and Long-Term Stability Test at High Temperature

[0078] When a high content of solid fatty acids is included together with wax, stability such as decrease in hardness and melting point may be affected. Therefore, caution is required when using high-content fatty acids in solid-phase formulations. This is expected to be because the fatty acids in the solid phase affect the crystal structure by participating in crystal formation, but the present invention is not limited to this theoretical mechanism.

Experimental Example 4-1. Cutting Hardness Measurement

[0079] The cutting hardness was measured and the results are shown in FIG. 3. To measure the cutting hardness, each sample was made into a cylindrical shape with a circular shape and a diameter of about 2.5 cm. It was measured using an applicator #30 equipped with a piano string at a speed of 2 cm/min at a depth of 1.5 cm using a durometer.

[0080] As a result, the hardness of Example 14 using isostearic acid, which is liquid at room temperature, was the highest. This is expected to be because the solid fatty acid affected the crystal structure of the wax, whereas the liquid fatty acid did not affect the crystal structure, but the present invention is not limited to this theoretical mechanism.

Experimental Example 4-2. Melting Point Measurement

[0081] The melting point according to the type of fatty acid was observed using DSC. DSC was observed while increasing the temperature by 10° C. per minute from 30° C. to 95° C. FIG. 4 shows the melting point measurement results.

[0082] As a result, it was found that when solid fatty acids were used, the melting point of solid formulations was lowered due to the melting point inherent in fatty acids. However, when liquid fatty acids were used, there was no phenomenon of lowering the melting point. This is expected because solid fatty acids participate in crystal formation and affect the crystal structure, whereas liquid fatty acids do not participate in crystal formation and do not affect the crystal structure. However, the present invention is not limited to this theoretical mechanism.

Experimental Example 4-3. High-Temperature Long-Term Stability Test

[0083] A stability test was conducted using the prepared sun stick. The experimental results are shown in Table 7 and Table 8 below.

[0084] As a result, Examples 11 and 12, which had a low melting point, did not maintain their original hardness at high temperatures, and showed a tendency to decrease their hardness when they were in high temperature conditions for a long period of more than one month.

[0085] Sweating is an important stability factor in solid oil-wax gel formulations. Sweating was observed when a high content of solid fatty acids was used, but no sweating was observed when liquid fatty acids were used.

TABLE-US-00007 TABLE 7 Type of 40° C. 45° C. 50° C. Sweating fatty acid Stability Stability Stability Stability Example 11 Myristic acid Δ X X X Example 12 Palmitic Acid Δ Δ X X Example 13 Stearic Acid ◯ ◯ ◯ X Example 14 Isostearic Acid ◯ ◯ ◯ ◯ Example 15 Behenic Acid ◯ ◯ ◯ Δ (In Table 7, ◯ means excellent stability, Δ means moderate stability, and X means poor stability.)

[0086] When solid fatty acids and liquid fatty acids were used together, sweating occurred when the content of liquid fatty acids was lower than that of solid fatty acids, as in Examples 16-19. On the other hand, as in Examples 20-22, it was confirmed that the sweating phenomenon was improved when the content of liquid fatty acid was higher. In addition, even if it contains solid fatty acids, as in Comparative Examples 2 and 3, if wax is not included or the wax content is low, the stick-type sunscreen is too soft, so it is not suitable as a solid cosmetic, and the stability over time at high temperature was not good.

TABLE-US-00008 TABLE 8 Solid fatty acid Liquid fatty acid Wax content 40° C. 45° C. 50° C. Sweating (Unit: wt %) (Unit: wt %) (Unit: wt %) Stability Stability Stability Stability Example 16 16 4 19 ◯ ◯ Δ X Example 17 16 8 19 ◯ ◯ Δ X Example 18 20 4 19 ◯ ◯ Δ X Example 19 20 8 19 ◯ ◯ Δ X Example 20 6 15 19 ◯ ◯ ◯ ◯ Example 21 3 18 19 ◯ ◯ ◯ ◯ Example 22 — 21 19 ◯ ◯ ◯ ◯ Comparative 16 8 0 X X X X example 2 Comparative 16 8 3 X X X X example 3 (In Table 8, ◯ means excellent stability, Δ means moderate stability, and X means poor stability)

Experimental Example 5. Evaluation of Water Resistance and Detergency

[0087] Stick-type sunscreens with the contents shown in Table 2 were prepared and evaluated in the same manner as above. Their water resistance evaluation and detergency evaluation are shown in Table 9 below. As a result, it showed high water resistance ratio and cleaning rate for all types of fatty acids.

TABLE-US-00009 TABLE 9 Water SPF before SPF after resistance Cleaning immersion immersion ratio (%) rate (%) Example 11 127.47 ± 32.16 305.68 ± 55.43 239.80 80.09 Example 12  92.21 ± 18.89 112.94 ± 35.63 122.48 77.75 Example 13  58.91 ± 13.64 163.91 ± 9.98  278.23 82.04 Example 14 127.41 ± 23.59  85.04 ± 20.72 66.74 82.8 Example 15 69.08 ± 4.54  61.06 ± 43.79 88.39 80.65