KR100376089B1 - A base composition for blocking ultraviolet rays and cosmetics containing the same - Google Patents

Abstract

The present invention treats fine particles of titanium dioxide with an alkyltriethoxysilane represented by Chemical Formula 1 and disperses the titanium dioxide into nanoparticles in silicon using a high pressure dispersing device, thereby preventing gelling from occurring and providing excellent sunscreen effect and excellent sunscreen effect. The present invention relates to a cosmetic of a sunscreen formulation prepared using the composition and the base, and the cosmetic of the present invention has excellent UV protection index, usability, and transparency.

Where

R ₁ is C ₃ -C ₂₂ alkyl,

R ₂ is C ₁ -C ₂₂ alkyl.

Description

A base composition for blocking ultraviolet rays and cosmetics containing the same}

An object of the present invention is to provide a sunscreen base that treats fine titanium dioxide with an alkyltriethoxysilane and disperses it as nanoparticles in a dispersion medium, thereby preventing gelling from occurring and exhibiting excellent usability and transparency.

Still another object of the present invention is to provide a sunscreen cosmetic which treats fine titanium dioxide with an alkyltriethoxysilane and disperses it as nanoparticles in a dispersion medium, thereby preventing gelling from occurring and exhibiting excellent usability and transparency.

Sunlight is part of everyday life and is thought to be good for health. However, as long hours of exercise, such as swimming, golf, tennis, and outdoor recreational activities increase, excessive sun exposure on the skin can be harmful and cause dermatitis or even skin cancer. In particular, inorganic salts (titanium oxide, zinc oxide, etc.) have been widely used as ultraviolet scattering agents to protect human skin from harmful UV regions. However, when a high concentration of fine particles of titanium dioxide is used, the feeling of use is bad, the clouding phenomenon appears on the skin and lowers the sense of transparency.

Particulate titanium dioxide is a sunscreen with high safety, stability, and transparency, and is used in paints, cosmetics, and chemical fibers. In particular, it is widely used in sunscreen products in the cosmetic field due to its ability to shield ultraviolet rays while being relatively transparent. Recently, the cosmetics market with a high UV protection index is growing in the Japanese market. The amount of organic sunscreen used in cosmetics is limited. In this situation, the amount of particulate titanium dioxide in the formulation is continuously increasing. Most particulate titanium dioxide is dispersed in oil such as silicone, which is a material having excellent water repellency, chemical resistance and weather resistance. Since the surface of the fine particle titanium dioxide exhibits hydrophilicity, agglomeration occurs strongly when dispersed in lipophilic silicone, and the original transparency and ultraviolet shielding effect are halved.

Numerous studies have been conducted to overcome these disadvantages. First, in order to develop a sunscreen base having excellent transparency and usability by dispersing coated fine titanium dioxide in silicon and using a sand mill, a turbo mill, etc. in order to use it as a sunscreen base having excellent safety, stability and transparency. Research is actively underway (WO 9816193).

In general, a pre-treated sample is dispersed using a normal homogenizer, resulting in poor dispersion and precipitation. The high shear homogenizer is dispersed using sand mill, etc., but the dispersibility is excellent and competitive in terms of price, but it shows problems such as iron contamination and long working time. High pressure homogenizer has the disadvantage that the equipment is relatively expensive, but it has the advantages of good productivity, excellent dispersibility, and short working time.

The second study is to modify the surface of particulate titanium dioxide in order to suppress photocatalytic activity on particulate titanium dioxide and to improve compatibility with the dispersion medium. Oxides such as alumina and silica are coated on the surface of the particles (JP 63045123) and surface treatment agents are used. Such surface treatment not only imparts light resistance but also greatly affects dispersibility and usability of resins and the like. In the case of finely divided titanium dioxide treated with excess gold ratio (aluminum stearate, aluminum laurate) to enhance usability and transparency, gelling occurs when dispersed in oil. Particulate titanium dioxide coated with methicone has advantages such as matte feeling when dispersed in oil.However, when water is added to sunscreen formulations, methicone reacts with water to generate hydrogen gas, causing changes over time. .

Therefore, the present inventors have overcome the above-mentioned disadvantages of the prior art and have produced a base having excellent usability and UV protection effect without a gelling phenomenon.

The present invention treats fine titanium dioxide with alkyltriethoxysilane and disperses the titanium dioxide into nanoparticles in silicon using a high-pressure dispersing device, thereby preventing gelling from occurring and providing a superior sunscreen base and excellent sunscreen effect. It relates to a manufacturing method.

The present invention also relates to a cosmetic composition having excellent sunscreen index, usability, and transparency prepared by using the sunscreen base in a sunscreen formulation.

Hereinafter, the present invention will be described in more detail.

Coating of Particulate Titanium Dioxide with Alkyltriethoxysilane

0.01-30% by weight of alkyltriethoxysilane (Formula 1) was added while 530 g of fine particle titanium dioxide was added to 3 L of purified water in a 5 L reactor and stirred and dispersed using an azi mixer or homomixer. The reaction was carried out by adding at a concentration of and then cooled to room temperature to coat the surface of the fine particle titanium dioxide with alkyltriethoxysilane. The fine titanium dioxide coated with alkyltriethylsilane was washed and dried, and then dried in air at an elevated temperature of 5 ° C./min at 110 ^° C. for 2-4 hours. Then, the fine particle titanium dioxide was coated by grinding with a hemmer mill.

[Formula 1]

Where

R ₁ is C ₃ -C ₂₂ alkyl,

R ₂ is C ₁ -C ₂₂ alkyl.

That is, the present invention contains 30 to 70% by weight of dispersion medium, 0.0001 to 20% by weight of dispersant and 10 to 60% by weight of fine particle titanium dioxide coated with alkyltriethylsilane. It relates to a UV blocking base produced by.

In the present invention, (a) the dispersion medium is liquid paraffin, triglycerine, squalane, olive oil, silicone oil and the like. Selected one or a mixture of two or more. The most representative is decamethylcyclopentasiloxane (DC 345, SF 1202, etc.).

(B) The dispersant is one or a mixture of two or more selected from polyglycerol fatty acid esters, sorbitan fatty acid esters, silicone surfactants, and polyglucosides as non-surfactants having HLB of 3-10. Most representative are silicone surfactants.

(C) The content of the alkyl triethoxysilane of the coated fine particle titanium dioxide may be 0.01-30% by weight, and preferably 3-20% by weight in consideration of the usability and stability of the cosmetic. When the content of the alkyl triethoxysilane is less than 0.01% by weight, it is difficult to effectively coat the fine particle titanium dioxide, and when the content of the alkyltriethoxysilane is more than 30% by weight, the fine particle titanium dioxide content is considerably reduced, which significantly reduces the UV blocking ability.

Hereinafter, the present invention will be described in detail with reference to Examples. However, the present invention is not limited only to these examples.

Preparation of Base Composition

Example 1 and Comparative Examples 1-3 are manufacturing examples of preparing a sunscreen base composition each having the following compositional components.

Component (%) Preparation Example Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Cyclomethicone 55 55 55 55 Cetyldimethicone polyol 10 10 10 10 Particulate Titanium Dioxide Coated with Alkyltriethylsilane 35 - - 35 Particulate titanium dioxide coated with aluminum stearate - 35 - - Dimethicone Coated Fine Titanium Dioxide - - 35 -

Example 1 was pretreated with azimuth mixer fine particulate titanium dioxide (35% by weight), cyclo methicone (55% by weight), cetyldimethicone polyol (10% by weight) coated with alkyltriethoxysilane and a high pressure dispersion device It was dispersed using.

Comparative Example 1 and Comparative Example 2 were prepared by the same process as in Example 1.

Comparative Example 3 was prepared by the same pretreatment process as Example 1 and dispersed using a general homo mixer.

Experimental Example 1 Measurement of Base Particle Size

Particle Size Measurement: Measurement was performed using a particle size analyzer (Malvern).

The particle size of the base obtained by dispersing particulate titanium dioxide in silicon is as follows.

Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Particle size 160 nm Gelling 160 nm 320 nm

The base of Example 1 exhibited excellent usability without the gelling phenomenon. The particle size is about 160 nm. In Comparative Example 1, when the aluminum stearate-coated fine particle titanium dioxide is used, the viscosity of the system increases rapidly when pretreatment or a high pressure dispersing apparatus is used, resulting in gelling. The pretreated sample was prepared using a high pressure disperser and the gelling did not loosen. This phenomenon depends on the amount of aluminum stearate coated. This phenomenon occurs when the amount of aluminum stearate is 10% or more. Due to this gelling phenomenon, it is not possible to manufacture sun products such as sun milk or sun cream.

In Comparative Example 3, the result of dispersing using a general homomixer without using a high pressure dispersing device was not possible because of poor dispersibility. In the long term stability, a lot of precipitation phenomenon was seen. From the above experiment, it can be seen that Example 1 is superior to Comparative Example 3 in terms of usability, transparency, and stability of the product.

Preparation of Cosmetics Containing Base Composition

Example 1 was used to prepare sun milk (Example 2) and sun cream (Example 3).

Sun milk (Comparative Example 4) and sun cream (Comparative Example 5) were prepared using Comparative Example 2.

The manufacturing method is as follows.

First oil component 1 is dissolved by heating to 70-75 ^O C. Oily component 2 is added to oily component 1 and sufficiently stirred. The stirred aqueous component is slowly added dropwise to the oil component and cooled to room temperature.

Raw material name Example 2 Example 3 Comparative Example 4 Comparative Example 5 Aqueous component Purified water imidazolidinyl urea To 1000.3 To 1000.3 To 1000.3 To 1000.3 Oily Ingredient 1 Methyl paraben propyl paraben 0.20.1 0.20.1 0.20.1 0.20.1 Oily component 2 Cetyl Dimethicone Copolyol 0.5 0.5 0.5 0.5 Octylmethoxycinnamate 7.5 - 7.5 - Particulate titanium dioxide / cetyl dimethicone copolyol dispersion coated with dimethicone / alkyltriethoxysilane 45.0 44.0 Particulate Zinc Oxide / Cetyl Dimethicone Copolyol Dispersion Coated with Dimethicone / Alkyltriethoxysilane 22.0 22.0 Particulate Zinc Oxide / Cetyl Dimethicone Copolyol Dispersion Coated With Dimethicone / Methicone 45.0 44.0 Particulate Zinc Oxide / Cetyl Dimethicone Copolyol Dispersion Coated With Dimethicone / Methicone 22.0 22.0

Experimental Example 2: Measurement of UV Protection Index

UV blocking index measurement method of Example 2, Example 3, Comparative Example 4 and Comparative Example 5 is as follows.

Subjects: 9 (7 males, 2 females)

Test area: left and right parts except the spine of the back

Light source: ORIEL Solar Simulator 81293 (Xenon UV Lamp 1kW, unfiltered)

Photometer: IL1700 Radiometer, SED 240 probe

Sun Protection Index (SPF) Measurement

The amount of ultraviolet light emitted from the solar simulator lamp to the test site was adjusted to 20-100 mJ / cm ² and irradiated to the back of the test subject. After 24 hours, minimal erythema amount (MED) was confirmed.

In order to confirm the UV blocking effect of the sample, the sample was uniformly coated with a thickness of 2 μl / cm ^{2 on} the subject's back and left to dry for 15 minutes. The UV irradiation window was attached to each sample application site and fixed, and other parts except the irradiation window were irradiated with UV rays by blocking the UV using a leather and a towel.

Based on the subject's MED, SPF 50 anticipated samples were tested with SPF 15-40, SPF100 anticipated samples with SPF 40-65, and gradually increasing UV dose. The minimum erythema amount was determined after 24 hours of ultraviolet irradiation, and the UV blocking effect of the sample was calculated according to the following formula.

The result of measuring the ultraviolet-ray blocking effect (SPF) of Example 2, Example 3, the comparative example 4, and the comparative example 5 is as follows.

name Example 2 Example 3 Comparative Example 4 Comparative Example 5 Subject 1 65 or more 40 or more 60 or more 35 or more Subject 2 65 or more 40 60 or more 35 Subject 3 65 or more 40 100 or more 35 Subject 4 over 90 45 70 or more 40 Subject 5 over 90 46 100 or more 46 Subject 6 105 and above 48 110 and above 48 Subject 7 115 and above 42 110 and above 42 Subject 8 122 and above 49 or more 120 or more 49 or more Subject 9 126 49 or more 120 49 or more Average 126 50 120 50

It can be seen from the above that Examples 2 and 3, which are cosmetics prepared in Example 1, which is a base of the present invention in which particulate titanium dioxide coated with alkyltriethoxysilane are dispersed as nanoparticles in a dispersion medium, exhibit excellent UV blocking effect. have. In addition, cosmetics prepared with a base containing fine titanium dioxide coated with dimethicone also had excellent UV protection.

However, as a result of observing viscosity and usability over a long period of time, cosmetics prepared with a base containing fine titanium dioxide coated with dimethicone (Comparative Example 4 and Comparative Example 5) had increased viscosity due to increased agglomeration of particles and a feeling of use. It became a fall. In addition, methicone reacts with water to generate hydrogen gas, causing the tube container to swell. On the other hand, the cosmetics (Examples 2 and 3) made of a base containing particulate titanium dioxide coated with alkyltriethoxysilane did not have agglomeration of particles, thereby maintaining viscosity and maintaining a feeling of use. In addition, since no hydrogen gas is generated in the tube vessel, the tube vessel does not swell.

Example (cmpoise) Example 2 Example 3 Comparative Example 4 Comparative Example 5 1 day 3000 5000 3000 5000 7 days 3000 5000 6000 9000 15th 3100 5100 30000 30000 30 days 3100 5100 50000 60000 90 days 3100 5100 More than 50000 More than 60000

As described above in detail, the fine titanium dioxide coated with the alkyltriethoxysilane of the present invention was dispersed using a high pressure dispersing device to disperse the nanoparticles into the dispersion medium, resulting in no gelling phenomenon and excellent usability and UV protection effect. A sunscreen base was prepared. As a result of applying this base to a sunscreen product, a product having excellent transparency, high UV index, and natural usability was produced.

Claims (8)

In the UV protection base composition comprising particulate titanium dioxide, a dispersion medium and a dispersant, the particulate titanium dioxide is coated with an alkyltriethoxysilane of the formula (1), the coated particulate titanium dioxide is dispersed in nanoparticle size in the dispersion medium UV protection base composition characterized in that. [Formula 1] Where R ₁ is C ₃ to C ₂₂ alkyl, R ₂ is C ₁ to C ₂₂ alkyl. The base composition for sun protection according to claim 1, wherein the dispersion medium is a single substance or a mixture of two or more selected from the group consisting of liquid paraffin, triglycerine, squalane, olive oil, silicone oil and decamethylcyclopentasiloxane. The ultraviolet light according to claim 1, wherein the dispersing agent is a single substance or mixture of two or more selected from the group consisting of polyglycerin fatty acid ester, sorbitan fatty acid ester, silicone surfactant, and polyglucoside as HLB is a non-surfactant between 3-10. Blocking base composition. The base composition for sunscreen according to claim 1, wherein the particulate titanium dioxide coated with alkyltriethoxysilane is dispersed in an amount of 10 to 60% by weight based on the total base composition. 5. The UV blocking base composition according to claim 4, wherein the content of the alkyl triethoxysilane in the coated fine titanium dioxide is 0.01 to 30% by weight. The base composition for sun protection according to any one of claims 1 to 5, wherein the fine particle titanium dioxide coated with alkyltriethoxysilane is dispersed in a dispersion medium by using a high pressure dispersing apparatus. A sunscreen cosmetic comprising a sunscreen base composition of any one of claims 1 to 6. The sunscreen cosmetic composition according to claim 7, wherein the sunscreen base composition comprises 1 to 70% by weight of the total cosmetic.