A method for preparing silica with ultraviolet blocking effect and silica prepared therefrom

Abstract

A method for preparing ultraviolet-blocking silica and the ultraviolet-blocking silica prepared therefrom are disclosed. According to the present invention, the method for preparing ultraviolet-blocking silica and the ultraviolet-blocking silica prepared therefrom simplify the preparation process by eliminating the use of a mold, thereby shortening the preparation time. This overcomes the difficulties in mold manufacturing and removal caused by using a mold in silica preparation, and allows for the control of silica particle size and morphology according to the manufacturer's needs while reducing production costs. Furthermore, by employing an ultraviolet-blocking agent, silica with improved ultraviolet-blocking efficiency can be provided.

Description

Technical Field

[0001] This invention relates to a method for preparing ultraviolet-blocking silica and the ultraviolet-blocking silica prepared therefrom, and more specifically to a method for preparing ultraviolet-blocking silica and the ultraviolet-blocking silica prepared therefrom, which simplifies and simplifies the preparation process by not using a mold, enables the realization of particle size and morphology according to the manufacturer's requirements while reducing production costs, and particularly improves ultraviolet-blocking efficiency. Background Technology

[0002] The pursuit of beauty has always been a human instinct throughout history. However, in recent years, there has been an increasing trend of attention being paid to body management, beauty treatments, or cosmetics in order to present a more beautiful self.

[0003] Furthermore, not only women, but also men are starting to pay attention to cosmetics for skin management, which is constantly expanding the cosmetics market and leading to the launch of various types of cosmetics on the market.

[0004] Generally speaking, cosmetics can be broadly classified into basic cosmetics, makeup bases, and color cosmetics. They are prepared as solid, liquid, or gel-like cosmetic materials, and the containers used to store them are also diverse.

[0005] Recently, functional cosmetics that can perform various functions such as moisturizing, whitening, wrinkle improvement, UV protection, acne relief, atopic relief, anti-inflammatory or keratolytic effects have also gained widespread consumer acceptance.

[0006] In addition, pigments are widely used not only in color cosmetics but also in skincare cosmetics in cosmetic formulations. Pigments are coloring components in cosmetics that are insoluble substances dispersed in aqueous and oil phases, such as mica, kaolin, and silica.

[0007] Among the diverse pigments, inorganic pigments consist of white pigments, colored pigments, and structural pigments. First, white pigments such as titanium dioxide and zinc oxide are used to cover skin imperfections by masking the underlying skin color. Next, colored pigments such as iron oxide, ultramarine, and ferrocyanide impart colors like red, yellow, black, blue, and green. Finally, structural pigments such as silica, mica, and kaolin act as diluents, adjusting color tone and the adhesion and gloss of cosmetics, playing a crucial role in cosmetic formulations.

[0008] Among such pigments, silica is a representative example of a pigment that improves the rough texture of cosmetics and absorbs sweat and sebum from the skin. For this reason, silica is widely used in cosmetic formulations, from base makeup and spot treatments to UV blockers and skincare products that maintain the makeup's finish and provide smooth, oil-free skin.

[0009] Generally, the silica used in cosmetics and personal care products is amorphous silica, meaning it does not have a definite form. Although the silica used in cosmetics is amorphous, it exhibits different properties depending on its shape, particle size, and surface condition. For this reason, silica varies in its malleability, spreadability, and other properties depending on its characteristics, and it is particularly important to make good use of these properties when using silica in cosmetic formulations.

[0010] Recently, efforts have been made to develop various forms of silica, such as porous and hollow silica.

[0011] Porous silica has the unique property of locking in specific substances within its pores, and at the same time, it can have a wider range of functions.

[0012] Generally, silica (SiO2) with hollow forms is prepared using a mold. Such molds are classified as hard type and soft type. Hard type molds are typically made of polymers such as latex, polystyrene or polyacrylate, polymethyl methacrylate (PMMA), or inorganic materials such as calcium carbonate, carbon, and zinc oxide.

[0013] Utilizing the physical properties of such rigid molds, diverse and precisely defined internal morphologies required by manufacturers can be produced. Uniform and consistent internal morphologies can be achieved, offering high reproducibility during fabrication. However, the fabrication process is time-consuming and complex. Furthermore, it suffers from the disadvantages of difficulty in creating the mold itself and the difficulty in removing the internal mold after silica preparation.

[0014] On the other hand, soft-form molding utilizes colloidal particles such as micelles, vesicles, and emulsions. Using soft-form molding to prepare hollow silica offers advantages such as simple processing, ease of internal molding, and easy removal of the internal mold after silica preparation. However, it also frequently results in internal morphology differing from the desired shape, with limited or non-uniform internal formation and varying sizes. Furthermore, structural stability and monodispersity are disadvantages.

[0015] Therefore, there is an urgent need to develop a silica preparation method that can improve the problems of the preparation methods in the above-mentioned existing technologies, simplify the preparation process without the use of a mold, reduce production costs while achieving particle size and morphology according to the manufacturer's requirements, and especially improve ultraviolet blocking efficiency. Summary of the Invention

[0016] The embodiments of the present invention provide a method for preparing silicon dioxide, which simplifies and simplifies the preparation process and shortens the preparation time by eliminating the use of a mold when preparing silicon dioxide.

[0017] Furthermore, embodiments of the present invention aim to overcome the disadvantages of difficulties in mold manufacturing and mold removal caused by the use of molds in the preparation of silicon dioxide.

[0018] Furthermore, embodiments of the present invention aim to reduce production costs while achieving the particle size and morphology of silica according to the manufacturer's needs.

[0019] Furthermore, embodiments of the present invention provide a silicon dioxide that, by incorporating it into an ultraviolet blocking agent, can improve ultraviolet blocking efficiency.

[0020] According to one aspect of the present invention, a method for preparing silica with ultraviolet blocking effect can be provided, comprising: dispersing sodium silicate in a sol-gel state; subjecting the dispersed sodium silicate to an acid treatment reaction to form active silicic acid; and maintaining the acid treatment reaction for a predetermined time to polymerize silica.

[0021] The formation of the active silicic acid and the polymerization of silica can be achieved by the following chemical reaction:

[0022] <Chemical Reaction Formula>

[0023]

[0024] The method for preparing silicon dioxide with ultraviolet blocking effect according to the present invention may further include:

[0025] The steps include: removing moisture from the polymerized silica by high-pressure / high-frequency filtration; mechanically pulverizing the filtered silica; and ultrasonically grinding the pulverized silica.

[0026] The acid used in the acid treatment reaction may be selected from one or more of the group consisting of HCl, H2SO4, HNO3, and combinations thereof.

[0027] The acid treatment reaction can be carried out in the pH range of 1.0 to 5.0.

[0028] The polymerization of the silica can be achieved by a dehydration condensation reaction.

[0029] During the acid treatment reaction, the temperature of the acidic solution can be increased from 0.5°C / min to 30°C / min.

[0030] The temperature rise can be from 70°C to 100°C.

[0031] The reaction time can be from 1 hour to 4 hours.

[0032] During the acid treatment reaction, the particle size and morphology of the silica can be adjusted by regulating the temperature rise of the acidic solution and the reaction time.

[0033] The filtration can be carried out at pressures ranging from 10 psi to 50 psi.

[0034] According to another aspect of the present invention, a silicon dioxide with ultraviolet blocking effect prepared by the aforementioned silicon dioxide preparation method can be provided.

[0035] According to another aspect of the present invention, a silicon dioxide with ultraviolet blocking effect can be provided, characterized in that it is prepared by the following chemical reaction:

[0036] <Chemical Reaction Formula>

[0037]

[0038] Invention Effects

[0039] The embodiments of the present invention can provide a method for preparing silicon dioxide that simplifies and simplifies the preparation process by eliminating the need for a mold and shortening the preparation time.

[0040] Furthermore, it can overcome the disadvantages of difficulties in mold manufacturing and mold removal caused by the use of molds in the preparation of silica.

[0041] Furthermore, it can reduce production costs while achieving the particle size and morphology of silica according to the manufacturer's needs.

[0042] Furthermore, embodiments of the present invention may provide a silicon dioxide that, by incorporating it into an ultraviolet blocking agent, can improve ultraviolet blocking efficiency. Attached Figure Description

[0043] Figure 1 This is a flowchart illustrating a method for preparing silicon dioxide according to an embodiment of the present invention.

[0044] Figure 2 This is a graph showing the ultraviolet blocking efficacy of a silica ultraviolet blocker prepared in a manner with diverse particle sizes and morphologies according to an embodiment of the present invention.

[0045] Figure 3 This is a graph showing the ultraviolet blocking efficacy of a silica ultraviolet blocker prepared by varying the temperature rise time according to an embodiment of the present invention. Detailed Implementation

[0046] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein, but can be embodied in other forms. Rather, the embodiments described herein are provided to make the disclosure thorough and complete, and to fully convey the technical concept of the present invention to those skilled in the art. Throughout the specification, the same reference numerals denote the same structural elements.

[0047] Figure 1 This is a flowchart illustrating a method for preparing silicon dioxide according to an embodiment of the present invention. Figure 2 This is a graph showing the ultraviolet blocking efficacy of a silica ultraviolet blocker prepared with diverse particle sizes and morphologies according to an embodiment of the present invention. Figure 3 This is a graph showing the ultraviolet blocking efficacy of a silica ultraviolet blocker prepared by varying the temperature rise time according to an embodiment of the present invention.

[0048] Reference Figures 1 to 3 An embodiment of the present invention provides a method for preparing silica, which may generally include: step S100, dispersing sodium silicate in a sol-gel state; step S200, subjecting the dispersed sodium silicate to an acid treatment reaction to form active silicic acid; and step S300, maintaining the acid treatment reaction for a certain period of time to polymerize silica.

[0049] Unlike existing technologies, the silica (SiO2) prepared according to an embodiment of the present invention is prepared without the use of a mold. Specifically, it is prepared by a polymerization process based on a continuous acid treatment reaction and a controlled rate of temperature rise of the acid solution.

[0050] First, in step S100, sodium silicate (Na2SiO3) is prepared and dispersed in pure water in a sol-gel state. Then, in step S200, activated silicic acid (H2Si2O5) is formed within a pH range of 1.0 to 5.0 using a strong acid treatment reaction. The formed active silicic acid is continuously polymerized under strong acid conditions. Finally, in step S300, silica (SiO2) is prepared through a polymerization reaction based on dehydration condensation.

[0051] The formation of the active silicic acid and the polymerization of silica can be achieved by the following chemical reaction formula.

[0052] <Chemical Reaction Formula>

[0053]

[0054] During the polymerization of silica, the pH range is maintained between 1.0 and 5.0. To maintain this pH, a cation exchange resin is preferably used to continue removing sodium ions.

[0055] If activation occurs at a pH below 1.0, outside the aforementioned range, the reaction with the acid used will fail, resulting in an excess of strong acid that prevents proper condensation. On the other hand, if activation occurs at a pH above 5.0, the reverse reaction will not easily form active silicic acid or silica, thus preventing a normal reaction.

[0056] The acid used in the acid treatment reaction may be selected from one or more of the group consisting of HCl, H2SO4, HNO3, and combinations thereof.

[0057] Furthermore, during the acid treatment reaction, the temperature of the acidic solution can be increased from 0.5°C / min to 30°C / min, and preferably from 70°C to 100°C. Additionally, the reaction time is preferably 1 hour to 4 hours, after which the average particle size is grown to 50–1500 nm, and then cooled to terminate the reaction.

[0058] In the corresponding process, the morphology and average particle size of colloidal silica particles are determined based on the rate of temperature rise of the acidic solution and the reaction time. If the acidic solution rises too slowly (less than 0.5°C / min), there is a problem of excessively large internal morphologies forming, or insufficient yield. On the other hand, if the temperature rises too rapidly (more than 30°C / min), sufficient morphology cannot be formed due to inadequate internal morphology.

[0059] In addition, the temperature range should be maintained between 70°C and 100°C. If the reaction temperature is below 70°C, the reaction will not be fully achieved due to low reactivity. If the temperature exceeds 100°C, the reaction will be difficult to control due to changes in pH and component ratio caused by boiling of water.

[0060] Furthermore, in relation to the reaction time, if the reaction time is less than 1 hour, the polymerization of silica is not sufficiently achieved, and if it is more than 4 hours, problems arise due to the formation of excessively large particles, resulting in a state where the internal morphology is not properly balanced.

[0061] As previously described, silica is polymerized within the range described above, and sodium (Na) ions, which are a byproduct of the active silicic acid reaction, are removed using a cation exchange resin. This is because, if the sodium byproduct is not properly removed, it can act as a hindering factor and may result in low-quality active silicic acid and silica.

[0062] In step S400, water, a byproduct formed along with the polymerized silica, is removed by high-pressure / high-frequency filtration. In typical silica purification processes, water removal is achieved through high-temperature drying; however, in this invention, filtration is used to obtain more uniform silica, with pressure conditions ranging from 10 psi to 50 psi.

[0063] During filtration, if the pressure is less than 10 psi, the low filtration rate will result in an insufficient yield. If the pressure exceeds 50 psi, the high pressure may damage the filter or introduce larger silica particles, leading to a slight decrease in quality. Furthermore, by using high-frequency filtration simultaneously with high-pressure conditions, a higher quality silica can be purified in a single pass.

[0064] Next, mechanical crushing (step S500) and ultrasonic grinding (step S600) were performed in sequence to prepare smaller and more uniform silica compared to the previous silica.

[0065] <Comparative Examples, Examples 1 to 6: Preparation of Silica>

[0066] Table 1

[0067]

[0068]

[0069] As shown in Table 1 above, silicon dioxide was prepared by changing the temperature rise time and reaction time, and the comparative examples and the samples of Examples 1 to 6 were prepared accordingly.

[0070] In the comparative example, the reaction temperature was directly raised to 80°C and silica was prepared. In Examples 1 to 6, the temperature rise time was 0.5°C / min to 30°C / min, and the reaction time varied from 1 hour to 4 hours and silica was prepared.

[0071] <Preparation of Silica in Examples 1, 6, and 7 to 15>

[0072] Table 2

[0073]

[0074] As shown in Table 2 above, silicon dioxide was prepared by changing the temperature rise time and reaction time, and the samples of Examples 1, 6 and 7 to 15 were completed accordingly.

[0075] <Preparation of UV Blocking Agents>

[0076] To evaluate the UV blocking effect of the screened silica, samples were prepared by coating each UV blocker as shown in Tables 3 and 4 below. The method for preparing the UV blockers is as follows: First, the oil and aqueous phases were heated to 85°C to completely dissolve all components. Next, the oil phase was slowly inserted into the oil-water phase using a homogenizer (3600 rpm, 5 minutes). After emulsification, silica pigment was added to the outer stage of the emulsion, and finally, a preservative was added to complete the process. Table 3 shows examples using silica classified by particle size and morphology, and Table 4 shows examples using silica with the same particle size but different hollow particle sizes.

[0077] Table 3

[0078]

[0079]

[0080] Table 4

[0081]

[0082] <Effects of UV blockers containing silica of different sizes and shapes>

[0083] Figure 2 The results confirm the UV blocking effects (SPF and PA) of the UV blockers prepared according to the preparation methods in Table 3. Examples 16 to 21, which used silica from Examples 1 to 6, all exhibited higher SPF and PA than Comparative Example 2, which used comparative examples. In particular, Examples 19 to 21 showed excellent results, confirming that smaller particle sizes resulted in higher SPF and PA when using hollow silica compared to porous silica.

[0084] <Effects of UV blockers containing hollow silica of varying sizes>

[0085] Figure 3 The results confirm the UV blocking effects (SPF and PA) of the UV blockers prepared according to the preparation method in Table 4, with Examples 23 to 25 showing good results. In particular, it was confirmed that the UV blockers using silica with a shorter temperature rise time exhibited higher SPF and PA.

[0086] Furthermore, as confirmed in Tables 1 and 2, the particle size and morphology of the silica can be adjusted during the acid treatment reaction by regulating the temperature rise of the acidic solution and the reaction time. Therefore, since the particle size and morphology of silica can be achieved according to the manufacturer's needs, it has the advantage of being able to prepare silica morphology and size in a tailored manner to the characteristics of various cosmetic compositions.

[0087] The silica preparation method according to the embodiments of the present invention described above simplifies and simplifies the preparation process by eliminating the use of a mold during silica preparation, and shortens the preparation time. It overcomes the disadvantages of difficulties in mold manufacturing and removal caused by using a mold during silica preparation, and can reduce production costs while achieving the particle size and morphology of silica according to the manufacturer's needs.

[0088] Furthermore, by employing ultraviolet blocking agents, silica can be provided to improve ultraviolet blocking efficiency.

[0089] Although the invention has been described above with reference to one embodiment, those skilled in the art can make various modifications and alterations to the invention without departing from the spirit and scope of the invention as set forth in the claims. Therefore, any modifications that substantially incorporate the structural elements of the claims should be considered to fall within the technical scope of the invention.

Claims

1. A method for preparing silica with ultraviolet blocking effect, wherein, include: The step of dispersing sodium silicate in a sol-gel state; The step of subjecting the dispersed sodium silicate to an acid treatment reaction to form active silicic acid; as well as The step of maintaining the acid treatment reaction for a specified time to polymerize silica. During the acid treatment reaction, the temperature of the acidic solution increases from 0.5°C / min to 30°C / min.

2. The method for preparing silica with ultraviolet blocking effect according to claim 1, wherein, Also includes: The step of removing moisture from the polymerized silica by high-pressure / high-frequency filtration; The step of mechanically pulverizing the filtered silica; as well as The step of ultrasonic grinding the pulverized silicon dioxide.

3. The method for preparing silica with ultraviolet blocking effect according to claim 1, wherein, The acid used in the acid treatment reaction is selected from one or more of the group consisting of HCl, H2SO4, HNO3, and combinations thereof.

4. The method for preparing silica with ultraviolet blocking effect according to claim 1, wherein, The acid treatment reaction is carried out in the range of pH 1.0 to pH 5.

0.

5. The method for preparing silica with ultraviolet blocking effect according to claim 1, wherein, The temperature rises to 70°C to 100°C.

6. The method for preparing silica with ultraviolet blocking effect according to claim 1, wherein, The reaction time is 1 to 4 hours.

7. The method for preparing silica with ultraviolet blocking effect according to claim 2, wherein, The filtration was carried out at a pressure of 10 psi to 50 psi.

8. A type of silicon dioxide, wherein, The silica is prepared by the method for preparing silica with ultraviolet blocking effect according to any one of claims 1 to 6.

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