Nano-free silica particles having high specific surface area and manufacturing method therefor

Abstract

The present invention relates to nano-free silica particles having a high specific surface area and a manufacturing method therefor and, specifically, to silica particles which are spherical silica for cosmetics having a diameter of 1 to 30 um obtained by using water glass, are nano-free as a measurement result by an electron microscope (SEM) and have a specific surface area of at least 200 m2 / g. A cosmetic material comprising the silica particles according to the present invention can prevent nano-related hazards, and can increase the loading efficiency and stably maintain a physically adsorbed loaded material by increasing the specific surface area and reducing the average size of pores when used as a carrier for an active ingredient.

Description

Nano-free silica particles having a high specific surface area and a method for producing the same

[0001] The present invention relates to nano-free silica particles having a high specific surface area and a method for producing the same, and more particularly, to nano-free silica particles having a high specific surface area and a method for producing the same, which can prevent nano-hazards while producing spherical silica particles for cosmetics having a diameter of 1 to 30 um using water glass, increase specific targeting when used as a carrier for an active ingredient, increase the loading efficiency by making the average size of pores smaller, and stably maintain a physically adsorbed carrier substance.

[0002] [Research and development project supporting this invention]

[0003] [Project ID] 1425179684

[0004] [Assignment Number] 00277456

[0005] [Ministry Name] Ministry of SMEs and Startups

[0006] [Name of Project Management (Specialist) Agency] Small and Medium Business Technology Information Promotion Agency

[0007] [Research Project Name] Small and Medium Enterprise Technology Innovation Development Project

[0008] [Research Project Title] Development of High-Value-Added Cosmetic Materials Using Inorganic Particle-Based Stabilization Technology for Anti-Aging Active Materials

[0009] [Name of Project Performing Organization] Advanced Beauty Science Co., Ltd.

[0010] Research Period: July 17, 2023 - December 31, 2023

[0011] The content described below merely provides background information related to the present invention and does not constitute prior art.

[0012] Silica is an inorganic oxide of the siloxane and silane groups. Also known as silicon dioxide or silicic anhydride, it is a compound of silicon and oxygen. It is a major component of rocks and soil, and is found in trace amounts in natural waters in ionic and colloidal form. It is also a major component of quartz, crystal, agate, and opal.

[0013] In cosmetics, silica particles can help regulate sebum secretion, helping to maintain clean pores. They can also be used as a raw material to prevent powdered ingredients in cosmetics from tangling or forming lumps when they absorb moisture. Furthermore, they can be used in scrub cosmetic compositions to remove harmful substances, secretions, external contaminants, bacteria, and makeup. They also stimulate the nerves and blood vessels in the dermis and subcutaneous tissues, promoting blood flow and preventing fine wrinkles. They also facilitate the removal of dead skin cells, preventing the stratum corneum from thickening and maintaining a healthy epidermis, providing a peeling effect. They can also be used as a feel-enhancing agent in makeup products.

[0014] Traditionally, silica particles have been manufactured by slowly adding a weak acid to tetramethyl orthosilicate (TMOS) or tetraethyl orthosilicate (TEOS) to grow the particles. While this method makes silica particles relatively easy to produce, it is more expensive than water glass.

[0015] In addition, when silica particles are manufactured by adding acid using water glass instead of TMOS or TEOS, the reactivity is high, so fine nanoparticles are instantly generated, and not only is it difficult to control the size of the particles, but many nanoparticles are attached to the surface of the generated particles (Fig. 1, Fig. 2), making the surface rough and increasing the coefficient of friction, which not only causes a poor feel when used in cosmetics, but also considering the negative effects of nanoparticles on living organisms, a method for manufacturing new silica particles that do not contain nanoparticles is required. That is, nanomaterials can be formed in the process of manufacturing silica particles using a sodium silicate solution. Nanomaterials, when included as cosmetic ingredients, can cause nano-hazards and reduce the feel of cosmetics when used.

[0016] Regarding nanomaterials, the European Cosmetics Regulation (EC) 1223 / 2009 defines insoluble or biopersistent substances in the range of 1-100 nm as nanomaterials and requires that the presence of nanomaterials be reported to the Commission before placing a cosmetic product on the market, and that all ingredients in the form of nanomaterials be listed in the ingredients list. Furthermore, the Recommendation 2011 / 696 on nanoparticles published in 2011 recommends that a product can be considered nano-free if less than 50% of the particles are 100 nm or smaller when observed with a scanning electron microscope (SEM). This means that, assuming an average particle diameter of 10 microns (um), the product contains only a very small amount of particles 100 nanometers or smaller by weight or volume, which is less than one millionth.

[0017] The inventors of the present invention were able to obtain 'nano-free silica' by controlling important process variables in a method for manufacturing silica particles using water glass (Na2SiO3 aqueous solution).

[0018] [Prior Art Literature]

[0019] [Patent Document]

[0020] 1. Korean Patent Publication No. 10-2020-0102445 (August 31, 2020)

[0021] 2. Korean Patent Publication No. 10-2021-0120621 (October 7, 2021)

[0022] The technical problem to be achieved by the present invention is to solve the conventional problems, and to provide nano-free silica spherical particles and a method for producing the same, which can prevent nano-hazards while producing spherical silica particles for cosmetics having a diameter of 1 to 30 um using water glass, increase specific targeting when used as a carrier for an active ingredient, increase the loading efficiency by making the average size of pores smaller, and stably maintain a physically adsorbed carrier substance.

[0023] The present invention relates to a cosmetic spherical silica having a diameter of 1 to 30 um obtained using water glass,

[0024] As measured by scanning electron microscope (SEM), it is nano-free.

[0025] Specific surface area of ​​at least 200 m 2 / g silica particles are provided.

[0026] Preferably, the specific surface area of ​​the silica particles is 200 to 400 m 2 / g is.

[0027] In addition, the present invention

[0028] A first step of preparing a mixed solution by adding oil and an emulsifier to a mixture of water glass and an aqueous solution selected from the group consisting of an aqueous NaCl solution, an aqueous KCl solution, and an aqueous Na2SO4 solution, and stirring the mixture;

[0029] A second step of adding a weak acid or a weak acid aqueous solution to the above mixed solution and causing a reaction;

[0030] A third step of adding a strong acid solution to the reactants of the second step and reacting them; and

[0031] A method for manufacturing silica particles is provided, characterized by including a fourth step of drying the result of the third step.

[0032] Preferably, the concentration of NaCl, KCl or Na2SO4 in the mixture of the water glass and the aqueous solution is 0.5 to 25 wt%.

[0033] Specifically, the oil is liquid paraffin, kerosene or diesel oil.

[0034] Specifically, the emulsifier has an HLB (Hydrophilic Lipophilic Balance) of 4 to 6.

[0035] Specifically, the above weak acid is at least one selected from the group consisting of acetic acid, carbonic acid, citric acid, and lactic acid.

[0036] Specifically, the above strong acid aqueous solution is added so that the pH of the final aqueous solution becomes 5 to 7.

[0037] In addition, the present invention

[0038] Silica particles manufactured by the above silica particle manufacturing method are provided.

[0039] The present invention also provides a cosmetic comprising the silica particles.

[0040] According to the present invention, while manufacturing spherical silica particles for cosmetics having a diameter of 1 to 30 um using water glass, nano-hazards can be prevented, and when used as a carrier for an active ingredient, a non-targeting property can be increased, the loading efficiency can be increased by making the average size of pores smaller, and a nano-free silica spherical particle and a method for manufacturing the same can be provided that can stably maintain a physically adsorbed carrier substance.

[0041] Figure 1 is an electron microscope photograph of particles after treating water glass with a weak acid according to a conventional technique.

[0042] Figure 2 is an electron microscope photograph of broken particles during acid treatment with strong acid according to the prior art.

[0043] Figure 3 is a flowchart showing a silica manufacturing process according to one embodiment of the present invention.

[0044] Figure 4 is an electron microscope photograph of silica particles according to one embodiment of the present invention.

[0045] Below, with reference to the attached drawings, embodiments of the present invention are described in detail so that those skilled in the art can easily implement them. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein.

[0046] Throughout this specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise specifically stated.

[0047] The present invention relates to a cosmetic spherical silica having a diameter of 1 to 30 um obtained using water glass,

[0048] As measured by scanning electron microscope (SEM), it is nano-free.

[0049] Specific surface area of ​​at least 200 m 2 / g silica particles are provided.

[0050] In the present invention, “Nano free” as observed by scanning electron microscope (SEM) means that the product satisfies the nano free standard set by the European Cosmetics Committee, and that particles of 100 nm or less in size account for 50% or less in number as observed by scanning electron microscope, and that particles of 100 nanometers or less are contained in only an extremely small amount of less than one millionth by weight or volume.

[0051] Preferably, the silica particles of the present invention have a specific surface area of ​​200 to 400 m 2 / g, and the average pore size of the silica particles is 10 to 30 nm. In this case, when used as a carrier for an effective ingredient, the specific target can be increased, the average pore size can be reduced, thereby increasing the loading efficiency and stably maintaining the physically adsorbed carrier substance.

[0052] The silica particles according to the present invention are nano-free silica particles obtained through water glass, and when included in cosmetics, can fundamentally prevent nano-hazards, increase the loading efficiency of effective ingredients, and stably maintain the loading material.

[0053] Silica particles according to the present invention

[0054] A first step of preparing a mixed solution by adding oil and an emulsifier to a mixture of water glass and an aqueous solution selected from the group consisting of an aqueous NaCl solution, an aqueous KCl solution, and an aqueous Na2SO4 solution, and stirring the mixture;

[0055] A second step of adding a weak acid or a weak acid solution to the above mixed solution and causing a reaction;

[0056] A third step of adding a strong acid solution to the reactants of the second step and reacting them; and

[0057] It can be manufactured through a method for manufacturing silica particles characterized by including a fourth step of drying and crushing the result of the third step.

[0058] In particular, in order to manufacture nano-free silica, the present invention has a problem that during the acid treatment reaction from weak acid to strong acid, water droplets in the aqueous phase water glass coalesce, thereby reducing the specific surface area of ​​the final silica, increasing the pore size, resulting in low oil absorption, and low loading efficiency when used as a support. However, by adding NaCl, KCl, or Na2SO4 to the water glass, the surface tension of water in the water glass is lowered, thereby solving the problem of water drops coalescing during the acid treatment reaction. Preferably, NaCl is the best.

[0059] Hereinafter, the technical composition of each manufacturing step of the above silica particle manufacturing method will be examined in more detail with reference to Figure 1.

[0060] The method for manufacturing silica particles of the present invention uses a mixture of water glass and an aqueous solution selected from the group consisting of a NaCl aqueous solution, a KCl aqueous solution, and a Na2SO4 aqueous solution. At this time, the concentration of NaCl, KCl, or Na2SO4 in the mixture of water glass and the aqueous solution is preferably 0.5 to 25 wt%, more preferably 1 to 20 wt%. In this case, the specific surface area of ​​the silica produced can be increased, and the pore size can be appropriately reduced. The amount of the aqueous solution can be arbitrarily adjusted, and preferably 1 to 50 wt% of the mixture with water glass can be used. As the amount of the NaCl aqueous solution increases, the porosity of the silica produced also increases.

[0061] In the present invention, a hydrophilic emulsion (step 1) is created by adding oil and an emulsifier to a mixture of water glass and an aqueous solution. The oil used here is preferably hydrocarbon oil. Specifically, various types, such as liquid paraffin, diesel fuel, kerosene, or polybutene, can be used. Liquid paraffin or kerosene is preferred. This approach can improve safety, such as fire safety, and economic efficiency.

[0062] In addition, it is preferable that the emulsifier have an HLB (Hydrophilic Lipophilic Balance) of 4 to 6, and specific examples thereof include at least one selected from the group consisting of isorbitan stearate, sorbitan isostearate, sorbitan oleate, sorbitan linoleate, and polyglycerin polylinoleate. The amount of the emulsifier may be 0.1 to 20 parts by weight per 100 parts by weight of oil. If the amount of the emulsifier is too small, a sufficiently uniform emulsification cannot be made, resulting in poor particle uniformity. In addition, if the amount of the emulsifier is too large, the particle size becomes too small, making it impossible to obtain silica particles of a desired size.

[0063] When mixing the above oils, the ratio of the water phase and the oil phase can be arbitrarily adjusted, and preferably, the water phase, which is the inner phase, is included in an amount of 30 to 80 parts by weight, and more preferably, 50 to 70 parts by weight. This can simultaneously satisfy the productivity and homogeneity of the silica particles.

[0064] The method for manufacturing silica particles of the present invention includes a second step of adding a weak acid or a weak acid aqueous solution to the mixed solution of the first step and causing a reaction.

[0065] The above weak acid is not particularly limited, and specifically, one or more selected from the group consisting of acetic acid, carbonic acid, citric acid, and lactic acid can be used. When used as a weak acid aqueous solution, the concentration of the aqueous solution can be arbitrarily adjusted, and specifically, it can be prepared and used as an aqueous solution of 1 to 50 wt%, preferably 1 to 30 wt%. The amount of the weak acid or weak acid aqueous solution added can be used in an amount of 0.5 to 10 times the weight of the oil input. Preferably, the weak acid aqueous solution is prepared in two or more concentrations, and then a weak acid aqueous solution of low concentration is added sequentially, followed by an aqueous solution of high concentration. In this case, the surface of the silica particles produced is smoother, and the coefficient of friction is lowered, so that the flowability can be further improved.

[0066] The method for manufacturing silica particles of the present invention includes a third step of adding a strong acid aqueous solution to the reactants of the second step and causing a reaction.

[0067] The strong acid may be specifically sulfuric acid, hydrochloric acid, or nitric acid, and when used as a strong acid aqueous solution, the concentration of the aqueous solution may be prepared and used at 1 to 20 wt%. It is preferable that the amount of the strong acid aqueous solution added be such that the pH of the final aqueous solution becomes 5 to 7. In this case, the silica particles produced can be prevented from bursting and generating nanoparticles. Preferably, the strong acid aqueous solution is prepared at two or more concentrations, and a strong acid aqueous solution of low concentration is added first, and then a solution of high concentration is sequentially added. In this case, the surface of the silica particles produced can be smoother, and the coefficient of friction can be lowered, so that the flowability can be further improved.

[0068] The method for manufacturing silica particles of the present invention includes a fourth step of drying and crushing the silica resulting from the third step. Known methods can be applied for the drying and crushing.

[0069] The method for producing silica particles according to the present invention can prevent nano-hazards by preventing the generation of nano-particles while producing spherical silica particles for cosmetics of 1 to 30 um using water glass, and can produce nano-free silica that increases specific targeting when used as a carrier for an active ingredient, increases the loading efficiency by making the average size of pores smaller, and stably maintains a physically adsorbed carrier substance.

[0070] Hereinafter, the present invention will be described in detail through examples. However, the following examples are only illustrative of the present invention, and the present invention is not limited to the following examples.

[0071] [Example 1]

[0072] 300 kg of sodium silicate and 30 kg of a 10 wt% NaCl aqueous solution were mixed and stirred at room temperature to ensure uniformity. 200 kg of liquid paraffin and 20 kg of a mixture of sorbitan isostearate as an emulsifier were added, and stirred at room temperature to form a water-in-oil emulsion.

[0073] Here, 200 kg each of 1%, 2%, 5%, and 10% acetic acid aqueous solutions by weight were slowly added while taking care not to break the particles, thereby forming particles.

[0074] Here, 1%, 2%, 5%, 10%, and 20% hydrochloric acid aqueous solutions were slowly added by weight, respectively, and the final solution pH was adjusted to 5 to 7 to solidify the particles. Only the precipitated silica particles were collected, washed, dried, and sieved to produce nano-free silica. The results of taking an electron microscope photograph of the produced silica particles are shown in Fig. 4. As shown in Fig. 4, the nano-free state was observed.

[0075] [Example 2]

[0076] Nano-free silica was prepared in the same manner as in Example 1, except that a 20 wt% NaCl aqueous solution was used instead of the 10 wt% NaCl aqueous solution in Example 1. The prepared silica particles were photographed using an electron microscope and showed a nano-free state.

[0077] [Comparative Example 1]

[0078] Nano-free silica was prepared in the same manner as in Example 1, except that a 10 wt% NaCl aqueous solution was not used.

[0079] The specific surface area and average pore size of the manufactured examples 1 to 2 and comparative example 1 were measured and are listed in Table 1 below.

[0080] Example 1 Example 2 Comparative Example 1 Average particle size (um) 6.8 6.7 6.7 Specific surface area (m 2 / g)226261154Average pore size (nm)282140

[0081] As shown in Table 1 above, it can be confirmed that the silica particles manufactured according to the present invention have a high specific surface area and a small average pore size.

Claims

1. Cosmetic-use spherical silica having a diameter of 1 to 30 um obtained using water glass, As measured by scanning electron microscope (SEM), it is nano free. Specific surface area of ​​at least 200 m 2 Silica particles characterized by having / g.

2. In paragraph 1, The specific surface area of ​​the above silica particles is 200 to 400 m 2 Silica particles characterized by having / g.

3. A first step of preparing a mixed solution by adding oil and an emulsifier to a mixture of water glass; an aqueous solution selected from the group consisting of an aqueous NaCl solution, an aqueous KCl solution, and an aqueous Na2SO4 solution; and stirring; A second step of adding a weak acid or a weak acid aqueous solution to the above mixed solution and causing a reaction; A third step of adding a strong acid aqueous solution to the reactants of the second step and reacting them; and A method for producing silica particles, characterized by comprising a fourth step of drying the result of the third step.

4. In paragraph 3, A method for producing silica particles, characterized in that the concentration of NaCl, KCl or Na2SO4 in the mixture of water glass and aqueous solution is 0.5 to 25 wt%.

5. In paragraph 3 A method for producing silica particles, characterized in that the oil is liquid paraffin, kerosene or gasoline.

6. In paragraph 3, A method for producing silica particles, wherein the emulsifier has an HLB (Hydrophilic Lipophilic Balance) of 4 to 6.

7. In paragraph 3, A method for producing silica particles, characterized in that the above weak acid is at least one selected from the group consisting of acetic acid, carbonic acid, citric acid, and lactic acid.

8. In paragraph 3, A method for producing silica particles, characterized in that the strong acid aqueous solution is added so that the pH of the final aqueous solution is 5 to 7.

9. Silica particles manufactured by the method for manufacturing silica particles described in any one of clauses 3 to 8.

10. Cosmetics containing silica particles described in Article 1.

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