KR100481374B1 - Surface Modification Of Titanium Dioxide For Sunscreen - Google Patents

Abstract

The present invention relates to a cosmetic composition for the sunscreen using a surface treatment with silica and iron in order to maximize the long-wave UV protection effect and reduce the photocatalytic phenomenon by using ultra-fine titanium oxide.

Description

Surface Modification Of Titanium Dioxide For Sunscreen

The present invention relates to a surface treatment method of ultra fine powder titanium oxide for maximizing the sunscreen effect of the sunscreen cosmetics. More particularly, the present invention relates to a surface modification technique of ultrafine powdered titanium oxide using silica and iron oxide.

In general, ultraviolet rays are classified according to the length of the wavelength and the effect on the human body, and when they are irradiated excessively, it is known to cause various skin diseases and cancer. Ultraviolet radiation is long-wave ultraviolet (UV-A), which leads to premature aging and blackening of the skin, medium-wave ultraviolet (UV-B), which causes the skin to become red, creating a sun burn, causing strong inflammation or blistering. It is divided into short-wave ultraviolet (UV-C), which is not transmitted to the ground by light that directly destroys life or absorption by the ozone layer. In the past, long-wavelength ultraviolet light was welcomed because of its high effectiveness in treating inflammation, but it has recently been pointed out as a target for promoting skin aging due to degeneration of proteins in the dermis, capillary expansion, and destruction of nucleic acids (DNA).

Meanwhile, the medium wavelength ultraviolet rays, which are mostly absorbed by the epidermal part of the skin, are called harmful ultraviolet rays because they act rapidly on the epidermis and cause burns. The long-wave UV rays come into contact with the skin all year round, but there is no self-awareness, and the skin grows old without you knowing it.

In ultraviolet cosmetics, inorganic ultraviolet scattering agents, organic ultraviolet absorbers and the like are used as sunscreens. Organic UV absorbers mainly absorb medium wavelength UV rays, while inorganic UV absorbers mainly scatter long wavelength UV rays. UV absorbers protect the skin by absorbing ultraviolet light and converting it into energy such as reverse, vibration, fluorescence, and radicals. In contrast, the ultraviolet scattering agent blocks the ultraviolet rays by the refractive index of the light of the inorganic pigment. Inorganic pigments have recently been spotlighted because they are relatively safe for the skin, but they have many problems in whitening and applicability to the skin when used excessively. In particular, cloudiness suppression is recognized as the most important part of the quality requirements for sunscreen cosmetics.

Inorganic ultraviolet scattering agents include metal oxides such as titanium oxide, zinc oxide, and cerium oxide, and composites thereof. Titanium oxide and zinc oxide are spotlighted. Studies on the anti-burn cosmetics by these physical sunscreens include WO 93-11742 and EP 55-9319 using iron oxide, titanium oxide, zinc oxide, US 52-50289 using titanium oxide, and the like. As described above, titanium dioxide, which has the highest scattering effect among the metal oxides and is chemically stable, is mainly used. Titanium oxide is used as a raw material for cosmetics, but there are some problems.

The first is a problem of the touch surface (stiffness, poor applicationability) and the finish surface (white floating phenomenon) caused by the high compounding of the inorganic powder. In addition, in order to block ultraviolet rays, it is necessary to disperse the primary particles of the titanium fine particle inorganic powders and to stabilize them. When this dispersion is stable, the uniformity of the ultraviolet scattering agent can be achieved when applied to the skin. The second deteriorates other raw materials of cosmetics because of their activity as photocatalysts. Third, because it blocks even the visible light range, clouding occurs when used in cosmetics. Fourth, ultrafine titanium oxide acts as a phototoxic cell that affects intracellular nucleic acid (DNA) under sunlight.

In order to overcome the above problems and to meet the conditions as a sunscreen, it is treated with a coating method. The organic material is surface treated with fatty acids, amino acids, lecithin, etc. and the inorganic material is treated with silica, alumina, zirconia, etc. However, many problems are still pointed out to suppress the skin whitening and effective sun protection.

Therefore, the present inventors have studied the solution to the problems presented above, and found that the coating of silica and iron oxide on the surface of the ultrafine titanium oxide is a very effective way to maximize the UV blocking effect and reduce the photocatalyst phenomenon. It was made and completed the present invention. The present invention has a technical problem to improve the functionality as a cosmetic by producing a cosmetic composition to realize the maximization of the ultraviolet effect and at the same time suppress the photocatalytic phenomenon.

The present invention includes ultrafine titanium oxide coated silica and iron oxide coated titanium oxide coated with silica corresponding to 5.0 to 37.0 wt% of the ultrafine titanium oxide and 0.2 to 2.0 wt% of the ultrafine titanium oxide as an active ingredient. It provides a sunscreen cosmetic composition.

In addition, the present invention is a silica and iron oxide coated titanium oxide coated with ultrafine titanium oxide coated with silica and 5.0 to 37.0% by weight of the ultrafine titanium oxide and 0.2 to 2.0% by weight of the ultrafine titanium oxide and the calcined temperature 550 It provides a sunscreen cosmetic composition comprising silica and iron oxide coated titanium oxide calcined at ~ 650 ℃ as an active ingredient.

In another aspect, the present invention is the step of washing the ultrafine titanium oxide powder with a hydrochloric acid solution: Silicic acid (Silicic Acid) corresponding to 5.0 to 37.0% by weight of the ultrafine titanium oxide powder in a solution of Hexafluorosilicic Acid (Hexafluorosilicic Acid) Step of preparing a silicic acid saturated solution: The ultrafine titanium oxide powder washed with hydrochloric acid solution was added to the silicic acid saturated solution and boric acid was added to react, and the titanium oxide powder was separated by filtration and dried to coat silica. Preparation of the ultrafine titanium oxide powder prepared: iron oxide hydrate (FeOOH) corresponding to 0.5 to 2.0% by weight of the ultrafine titanium oxide powder in ammonium fluoride hydrofluoric acid (NH ₄ FHF) Was added to the solution to which the boronic acid was added and reacted to prepare ultrafine titanium oxide powder coated with iron oxide and silica. By providing a method for producing a cosmetic composition for blocking UV rays.

In the present invention, ultrafine titanium oxide is used as a sunscreen to improve the functionality by surface treatment with silica and iron oxide. Ultrafine titanium oxide is a chemically stable and high UV-protective inorganic oxide, and its use as a sunscreen is promising, but its use is limited due to clouding, photocatalytic action, texture and cytotoxicity. Accordingly, the present invention significantly reduced the photocatalytic action, the stiff feel, the cytotoxic action, and the like by removing the cloudiness by coating iron oxide thereon and increasing the blocking rate against long-wavelength ultraviolet rays.

In the present invention, the silica film is 5.0 to 37.0% by weight of the ultrafine titanium oxide, and iron oxide is coated at a level of 0.5 to 2.0% by weight. Hereinafter, the present invention will be described in detail.

Experimental samples were prepared using the Liquid Phase Deposition Technique at room temperature of 30 ° C. The ultrafine titanium oxide used in the present invention is a powder having a crystal composition of 70% by weight of anatase and 30% by weight of rutile as rutile (Degussa). Saturated Silyxic acid solution was prepared using 100 milliliters of a 1.49 molar concentration solution of nucleus phlosilic acidic acid, and titanium oxide (TiO ₂ ) treated with hydrochloric acid (HCl) solution was added to the saturated solution. Then, boronic acid is added and separated and dried to prepare silica-coated titanium oxide ultrafine powder.

In order to coat iron oxide, an ultrafine titanium dioxide powder coated with silica was supported on a solution of iron oxide hydrate (FeOOH) containing 1.0 mol of ammonium fluoride hydrofluoric acid (NH ₄ FHF) as a solvent. The coating amount of iron oxide was limited to 0.5 to 2% by weight in order to use the cosmetics. To this, 0.07 molar concentration of boronic acid is added to prepare an ultrafine powder of titanium dioxide coated with iron oxide and silica.

Examples 1 to 3 were coated by controlling the amount of iron oxide hydride (Iron Oxide Hydrate) in the fine powder coated with a silicic acid saturated solution. Comparative Examples 2 to 4 adjusted the amount of silica to be coated by controlling the amount of silicixide added, and the components and contents of Examples and Comparative Examples are shown in Table 1.

EXAMPLE

Example 1

Experimental samples were prepared using the liquid phase sedimentation method at room temperature of 30 ° C. A commercially available Daegu product was washed with hydrochloric acid solution 4.0g of ultrafine titanium oxide powder having a crystal composition of anatase 70% by weight and rutile 30% by weight. 0.2 g of silicic acid was added to 100 mL of 1.49 molar concentration of nucleated saxaflorosilic acid solution to prepare a saturated silicic acid solution, and titanium oxide washed with hydrochloric acid solution was added to the saturated silicic acid solution. 7.5 mL of boronic acid was then added and separated and dried to prepare a silica coated ultrafine titanium oxide powder.

4 g of the silica-coated ultrafine titanium oxide powder was separately collected. ₄ g of ultrafine titanium oxide powder coated with silica was supported on a solution in which 0.02 g of iron oxide hydrate (FeOOH) was added to 100 mL of 1.0 mol of ammonium fluoride hydrofluoric acid (NH ₄ F.HF). The coating amount of iron hydroxide was limited to 0.5 to 2% by weight in order to use it for cosmetic use. 600 mL of boronic acid at 0.07 molar concentration was added thereto to prepare iron oxide and silica-coated ultrafine titanium oxide powder.

Example 2

Instead of using 0.02 g of iron oxide hydrate (FeOOH) in Example 1, 0.06 g of iron oxide hydrate was used to prepare ultrafine titanium oxide powder coated with iron oxide and silica in the same manner as in Example 1.

Example 3

Instead of using 0.02 g of iron oxide hydrate (FeOOH) in Example 1, 0.06 g of iron oxide hydrate was used to prepare ultrafine titanium oxide powder coated with iron oxide and silica in the same manner as in Example 1.

Example 4

The iron oxide and silica-coated ultrafine titanium oxide powder prepared in Example 3 were calcined at 600 ° C.

Comparative Example 1

Commercially available 40 g of ultrafine titanium oxide powder having a crystal composition of 70 wt% anatase and 30 wt% of rutile was purchased from Daegu.

Comparative Example 2

Silica-coated ultrafine titanium oxide powder was prepared in the same manner as in Example 1 and using 0.2 g of SilyxEx in the same manner as in Example 1 using 0.2g of SilyxEx.

Comparative Example 3

Instead of using 0.2 g of silicic acid in Example 1, 0.8 g of silicic acid was used and silica-coated ultrafine titanium oxide powder was prepared in the same manner as in Example 1.

Comparative Example 4

Silica-coated ultrafine titanium oxide powder was prepared in the same manner as in Example 1, using 1.5 g of Silyxex instead of 0.2 g of Silyxex in Example 1.

Comparative Example 5

Iron oxide and silica-coated ultrafine titanium oxide powder prepared in Comparative Example 2 were calcined at 600 ° C.

Raw material name Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4  Titanium dioxide - - - 4.0g 4.0g 4.0g 4.0g  Nucleus phloxi silicic acid - - - - 100 mL 100 mL 100 mL  Silicic acid - - - - 0.2 g 0.8 g 1.5 g  Boronic acid 600 mL 600 mL 600 mL - 7.5mL 7.5mL 7.5mL  Silica coated titanium dioxide 4 g 4 g 4 g - - - -  Ammonium fluoride hydrofluoric acid 100 mL 100 mL 100 mL - - - -  Iron hydroxide 0.02 g 0.04g 0.06 g - - - -

Experimental Example 1 UV Protection Effect

In order to determine the UV blocking index of the surface-modified ultrafine titanium oxide simply and accurately, the UV blocking index was measured by the following method. (This method shows a correlation coefficient of 0.95 or more in comparison with the results of in vivo evaluation in Korean Cosmetic Journal Vol. 21, No. 2 (57-72)). The powder raw materials of Examples 1 to 3 and Comparative Examples 2 to 4 were mixed with a diamond mon (Diamont-N (vaseline)) in a volume ratio of 1: 2, and then evenly mixed with 0.75 mg / T on a transfer tape. Apply at the level of cm 2. Thereafter, it was dried for 15 minutes, and the UV protection index was measured using SPF-290 (USA, Solar light Co.). As a detector, a radiometer equipped with an ultraviolet probe (Radiometer, USA International Light Ltd.) was used. The measurement method was a UV protection index by measuring the time (t) to reach 45.0 J / ㎠ corresponding to the minimum erythema of skin type III at the light intensity of 3.7 × 10 J / min. ㎠. 1 shows the UV blocking indexes for Examples 1 to 3 and Comparative Examples 2 to 4. As a result of coating the iron oxide, it can be seen that the blocking efficiency against ultraviolet rays is increased.

On the other hand, the long wavelength UV protection index (PFA) is defined by the following equation.

Here, the minimum sustained instant blackening refers to a minimum amount of ultraviolet radiation in which faint blackening is basically recognized in all areas of the irradiation region within 2 to 4 hours after the long wavelength ultraviolet irradiation. Table 2 shows the long-wavelength ultraviolet protective index for Example 3, Comparative Example 2. As a result of coating the iron oxide, it can be seen that the blocking efficiency against long-wavelength ultraviolet rays was also increased.

Item Example 3 Comparative Example 2 Longwave UV Protection Index (PFA) 65.86 56.14

Experimental Example 2 Evaluation of Photocatalytic Activity

Photocatalytic activity was measured by the antifouling activity evaluation method which is convenient for measuring the absorbance of a colored film. The sol obtained by dispersing the surface-modified ultrafine powder raw material in the distilled water by the method of Example 3 and Comparative Example 2, respectively, was added dropwise dropwise while stirring in an emulsion. (Ultra fine powder 2g + Emulsion 30g + Distilled water 10g, takes about 20 minutes) As the photocatalyst concentration increases, the production time should be longer. The mixed solution is coated on a galvanized steel plate with a bar coater (Bar No.) 14 and dried for 1 day. After 20 minutes of immersion in a methylene blue solution, photocatalytic activity was evaluated using PCC-1 (ULVAC-RIKO Inc. Japan) after drying for 2 hours under shading conditions. Photocatalytic activity is expressed as the change in absorbance measured at any time relative to the initial absorbance. 3 shows the change of the photocatalytic effect after silica coating and the reduced photocatalytic effect even after iron oxide coating. It can be seen that the photocatalytic effect is maintained even after iron oxide coating.

Test Example 3 Evaluation of Photocatalytic Activity According to Heat Treatment

In order to evaluate the photocatalytic activity according to calcination, the heat treatment of the surface modified titanium dioxide ultrafine powders of Example 3 and Comparative Example 2 was performed at 600 ° C., respectively, to constitute Examples 4 and 5. After the heat treatment, the photocatalytic activity was measured in the same manner as in Test Example 2. FIG. 3 shows the photocatalytic effect of the silica-coated titanium oxide ultrafine powder after heat treatment and the photocatalytic effect after iron oxide coating. It can be seen that the photocatalytic effect is suppressed by calcination.

According to the present invention, the photocatalytic effect and cytotoxic effect are reduced according to the coating of silica on the ultrafine titanium oxide, but the ultraviolet ray blocking effect is reduced. Therefore, the coating of iron oxide on the powder induced an increase in UV blocking effect while maintaining the reduced photocatalytic activity. Since the surface-modified titanium oxide ultrafine powder has a color similar to that of the skin, the amount of use thereof can be increased than before, and thus a high blocking rate can be maintained.

1 is a view showing the ultraviolet blocking effect according to the silica content.

2 is a view showing the ultraviolet blocking effect according to the iron oxide content.

FIG. 3 is a view showing a photocatalytic effect according to silica coating of titanium oxide and a photocatalytic effect according to iron oxide coating of titanium oxide coated with silica.

Claims (4)

The ultrafine titanium oxide includes silica and iron oxide coated titanium oxide coated with silica corresponding to 5.0 to 37.0 wt% of the ultrafine titanium oxide, and 0.2 to 2.0 wt% of the ultrafine titanium oxide as an active ingredient. Cosmetic composition for sun protection. The cosmetic composition for sunscreen as claimed in claim 1, wherein the silica and iron oxide coated titanium oxide are further calcined at a calcination temperature of 550 to 650 ° C. Washing the ultrafine titanium oxide powder with a hydrochloric acid solution: adding a silicic acid corresponding to 5.0 to 37.0% by weight of the ultrafine titanium oxide powder to a nucleus floro silicic acid solution to prepare a saturated silicic acid solution: hydrochloric acid Preparing ultrafine titanium oxide powder coated with silica by adding ultrafine titanium oxide powder washed with a solution to a saturated silicic acid saturated solution, adding boronic acid and reacting, and filtering and drying the titanium oxide powder by filtering: silica coated ultrafine oxide powder Titanium powder is added to a solution in which iron oxide hydrate (FeOOH) corresponding to 0.5 to 2.0% by weight of ultrafine titanium oxide powder is added to ammonium fluoride hydrofluoric acid (NH ₄ FHF) and boronic acid is added to react. A sunscreen cosmetic bath comprising the steps of preparing a coated ultrafine titanium oxide powder Preparation method of water. The method of claim 3, wherein the silica and the iron oxide coated titanium oxide are further calcined at a calcination temperature of 550 to 650 ° C. 5.