KR101063540B1 - Manufacturing method of silica nano powder containing silver coating layer - Google Patents

Abstract

The present invention relates to a method of preparing a silica nanopowder containing silver coating layer having excellent stability and antimicrobial activity. More specifically, after mixing a predetermined amount of silicon alkoxide, a solvent, water and a catalyst in a reactor, silica particles having an average particle diameter of 75 nm to 150 nm are stirred. To prepare a silica powder coated with nano-sized silver particles by slowly adding a silver ion (Ag ⁺ ) precursor, stirring, washing and drying for a predetermined time, and dispersed in a dispersion solvent, After preparing a dispersion having an antimicrobial activity, a method of applying the dispersion to a cosmetic composition is provided.

Silver, nano, silica, dispersion, cosmetics

Description

Process for preparing silica nano-powder coated by silver nano-particles

The present invention relates to a method for producing a silver coating layer-containing silica nanopowder, and more particularly, after the silicon alkoxide is reacted in an alcohol solvent in the presence of a catalyst to form silica particles, to form a silver coating layer thereon, using the cosmetic It relates to a method for producing the composition for.

The core of nanoparticle technology for maximizing the properties and performance of nanomaterials can be classified into manufacturing technology of functional nanoparticles, materialization and functionalization of nanostructures, and maximization of performance by materials of nanocomposite materials. To date, nanoparticle manufacturing techniques have attracted much attention to the uniform size of the nanoparticles ranging from 10 ^-7 to 10 ^-9 m. Nanoparticle manufacturing techniques have been tried in various ways by mechanical, physical, and chemical methods, but there are still many problems to realize selective uniformity of size, and also regarding mass production process and manufacturing techniques of two or more nanocomposite particles. There are still technical limitations. In addition, in order to materialize the manufactured nanoparticles, the problem of securing regular and uniform dispersion and oxidation stability should be solved. Among the various functional nanoparticles, many basic researches and application stages of silver (Ag) -based and SiO ₂ , TiO ₂ , ZnO-based nanocomposites have been conducted, and in particular, chemical reduction methods, electrochemical methods, Synthesis of many silver nanoparticles has been developed and reported by the reduction method of silver ions by heat and light. The problem with the application of nanoparticles such as silver-based and SiO ₂ , TiO ₂ , ZnO-based materials is that they cannot be easily oxidized to maintain stability and dispersibility as nanoparticles, which has not been solved yet. In addition, there is a problem that the synthesis technology of uniform selective size in the range of 10 ~ 200nm size is impossible by the conventional reduction method and electrochemical synthesis method, and the problem of regular dispersion and stability in organic materials such as polymer matrix still remains. In particular, inorganic materials used in cosmetics have been applied to a variety of skin care, makeup, sunscreen products. In this case, when applied to the product as technical characteristics that inorganic materials should have, compatibility with other components should be excellent and precipitation, odor and discoloration should not occur. In addition, when applying skin, it should ensure safety, good adhesion, and no whitening phenomenon. In terms of effect, it should be excellent in UV protection and antibacterial effect depending on the application. Existing technologies have limitations in meeting these conditions.

There are many types of antimicrobials currently used, and they are largely classified into organic and inorganic antimicrobials. Organic antimicrobials have been used a lot of organic antimicrobials such as methyl parabens and propyl parabens to date because they are relatively easy to process and do not significantly affect the mechanical properties, transparency and color of the final product. However, there are reports of adverse effects on living skin cells and cause skin irritation.

As the stability of the organic antimicrobial agent is a problem to the human body, an inorganic antimicrobial agent that can compensate for the shortcomings of the organic type has attracted attention. Inorganic antimicrobial agent is an inorganic carrier such as zeolite, silica alumina, etc., which substitutes metal ions with excellent antimicrobial properties such as silver (Ag), copper (Cu), manganese (Mn), zinc (Zn), etc. Because of its skeleton structure, it has a large specific surface area and excellent heat resistance. On the other hand, metals that are toxic to microorganisms are generally very toxic to humans, but metals such as silver, copper, manganese, and zinc are one of the few metals with strong antibacterial properties and high stability. have.

Silicon (Si) is the second most abundant substance on the planet, and does not have direct bactericidal effects against plant pathogens, but it is known to increase disease resistance and stress resistance by plant absorption, and improves the feel and spread of use. It is also widely used as a cosmetic raw material for the purpose.

Silver (Ag) used as an antimicrobial agent is excellent in antibacterial activity, nontoxic, non-irritating, chemically durable and excellent in heat resistance. In addition, it releases silver ions over a long period of time and is excellent in antimicrobial durability. Various proposals have been made for the antibacterial mechanism of metal silver ions (Ag ⁺ ). First, microorganisms are killed by adsorbing and binding to -SH groups in proteins of microorganisms, causing cell transformation and condensation-dehydration reactions, making it difficult for metabolism and energy metabolism of microorganisms. Second, oxygen is converted into active oxygen partially by the catalytic action of an antibacterial metal such as silver. This active oxygen has a strong bactericidal action such as ozone and hydrogen peroxide. Third, since silver is nanoscale, it is possible to ingest microorganisms of about 100 nm to 200 nm, and there is an opinion that microorganisms are killed by respiratory disorders and metabolic disorders when ingested. But academia supports the first antimicrobial mechanism.

The composite material of silver-based nanoparticles is a technology that develops composite materials having functionalities such as antibacterial, deodorization, antistatic, etc. to plastic materials that are widely used not only in various industrial materials but also in everyday life products. Research is ongoing. Overseas research and development on the field has been mainly reported on basic research, and research on application and commercialization is rare. In the United States, many basic researches on the synthesis of silver nanoparticles have been published by the EL-Sayed Group at Georgia Institute of Technology, the Gezelter Group at Notre Dame University, the Murphy Group at South Carolina University, and the Wei Group at Purdue University. In France, the Pileni and Alikhani groups announced the synthesis of silver nanoparticles and their immobilization techniques for SiO2.In Japan, the company has already announced the technology of adding silver fine particles as an electromagnetic shielding material to polymer materials and adding them to paints and fibers. I've done it.

In Korea, basic research on the formation of silver-based nanoparticles has already been conducted in various ways such as electrochemical method, chemical reduction method, optical method, ultrasonic method, micro method, gamma ray irradiation method, and many research results have been reported. However, it is still unresolved until the development of a method for controlling the dispersibility and oxidation stability of silver nanoparticles and the synthesis of selective uniform nanoparticles has not been developed. It is difficult to synthesize.

As a method for producing an antimicrobial silica carrier, vapor phase decomposition method using silicon tetrachloride or the like (Japanese Patent Laid-Open No. 62-003011), a sol-gel method using silicon alkoxide (Japanese Patent Laid-Open No. 63 -166777), and neutralization of alkali silicate with acid It is known to carry an antimicrobial substance (silver, copper, gold, zinc, platinum, etc.) on a carrier prepared by a method prepared by the reaction (US Pat. No. 4675122).

However, the gas phase decomposition method is toxic and corrosive at the time of reaction, there are disadvantages such as the formation of pores only on the surface of the particles, the sol-gel method has the advantage of obtaining a high-purity powder, there is a problem of economic efficiency. In addition, the neutralization reaction method is the most widely used because of the low raw material price and easy handling in the manufacturing method, but since the mixing reaction between the raw materials is done by dropping method, the concentration of alkali silicate solution as raw material should be 20% or less. And, since the contact between the raw material is made locally, there is a disadvantage that the reaction is non-uniform. In addition, it is manufactured by washing the alkaline water for a long time to increase the pore volume (3 ~ 4 days / batch), the uniformity for each product load is large, the manufacturing cost is high, due to the long time aging / washing process There are disadvantages such as outflow of catalyst material. In addition, there is a problem that a complex process, that is, a crushing, assembling and the like during the catalyst particle size and shape control have to go through a manufacturing process.

The method of supporting the antimicrobial substance on the silica carrier prepared by the above method is roughly classified into an impregnation method, an ion exchange method, and a precipitation method. In the impregnation method, the carrier is contacted with a solution containing an antimicrobial substance and supported by spraying, evaporation drying, and adsorption. The spraying method is to spray and support a solution containing an antimicrobial component while putting the carrier in an evaporator while stirring. The evaporation drying method is a method in which a carrier is immersed in a solution containing an antibacterial substance and then the solvent is blown off. Ion exchange method is mainly used for supporting antimicrobial substances on silica, zeolite, alumina, etc., but it has the advantage of uniform distribution of antimicrobial substances. However, the amount of antimicrobial substances that can be supported is small, and it takes too much time to support them. .

As described above, the supporting method of the conventional antimicrobial substance has to carry the antimicrobial substance again after all of the carriers have been prepared, so that excessive time is spent on the supporting, and there is a limit to the content of the antimicrobial substance. Manufacturing costs also increase.

In addition, in the process of preparing the silica carrier by the method of producing the silica powder by the neutralization reaction, there is also a method of preparing the antimicrobial silica by inputting the raw material containing the antimicrobial material during the initial synthesis of raw materials, There is a disadvantage in that a large amount of antimicrobial material is lost.

That is, in the conventional method, it is not easy to manufacture a highly porous silica carrier, and there is a limit to the amount of an antibacterial substance that can be loaded thereon, and the manufacturing time is long and the manufacturing cost is high. In addition, in the case of supporting the antimicrobial substance on the carrier, since the antimicrobial substance must be supported on the already prepared carrier, it is difficult to carry it homogeneously, and the manufacturing process is complicated and the economy is inferior. In addition, even when the antimicrobial material is added to prepare a carrier, there is a disadvantage in that loss of the antimicrobial material is caused due to prolonged aging / washing process.

In addition, inorganic antimicrobial powders are less toxic and stable to heat than organics, but have a characteristic color of metal, which may be discolored when applied to a product, and have the disadvantages of low antimicrobial persistence and dispersibility.

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The problem to be solved by the present invention is to provide a method for producing a silver coating layer-containing silica nano powder excellent in antimicrobial activity and solvent dispersibility and stability.

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In order to achieve the above object, the present invention,

A first step of reacting silicon alkoxide in an alcohol solvent at 35 ° C. to 38 ° C. for 6 to 7 hours in the presence of a catalyst to form silica particles having an average particle diameter of 75 nm to 150 nm; And

And mixing the silica particles with the silver precursor in an alcohol solvent, and then adding a reducing agent to reduce the silver precursor to form a silver coating layer on the surface of the silica particles. It provides a method for producing a coating layer-containing silica nano powder.

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The silica nanopowder formed with the silver coating layer proposed by the present invention has excellent dispersibility and oxidative stability, does not cause discoloration and odor, and exhibits strong antibacterial activity even in a small amount, so that it can be used as an antiseptic when applied to external preparations such as cosmetics. It is possible. Therefore, when the silver coating layer-containing silica particles prepared in the present invention are blended into the cosmetic composition, long-term storage of various cosmetics is possible even without chemical preservatives that can cause skin irritation and allergic reactions to the human body.

The present invention provides a silica coating powder containing a silver coating layer.

The silver coating layer-containing silica nanopowder according to the present invention has a core / shell structure, and the silica nanopowder serves as a core, and a silver coating layer is formed on the surface of the core to form a shell.

The silica nanopowder that serves as the core preferably distributes its particle size within a certain range in terms of antimicrobial activity and stability.

The average particle diameter of the silica nanopowder according to the present invention is preferably 75nm to 150nm, more preferably 80nm to 90nm, if less than 75nm the silica nanopowder may penetrate the skin of the human body and cause toxicity, 150nm If exceeded, the surface area of the silica nanopowder decreases, which may lower the antimicrobial activity. Also exceeding 90 nm, the size of the particles becomes uneven.

 The shell layer is formed on the core made of the silica nanopowder as described above. In the present invention, silver having excellent antibacterial power can be used as the shell layer. Such a shell layer made of silver is uniformly formed on the surface of the core, and the thickness thereof is preferably 2 nm to 5 nm. The coating layer using silver may have a layer shape of a continuous and uniform form, but silver nanoparticles may be combined in the form of particles aggregated on the surface of the silica nanopowder.

As described above, the silver coating layer-containing silica nanopowder of the present invention has a silver layer formed on the surface of the nanoparticles, and thus may exhibit excellent antimicrobial activity. In particular, the size of the silica nanopowder constituting the core is limited within a specific range. By doing so, it can be suitably used in fields requiring stability and antimicrobial properties, such as cosmetic compositions.

The silver coating layer-containing silica nano powder according to the present invention is prepared by the following method.

The silver coating layer-containing silica nanopowder according to the present invention is largely divided into two processes, that is, it may be divided into a process of forming a silica nanopowder and a process of forming a silver coating layer therein.

In the process of forming the silica nanopowder is appropriately adjusted so that the average particle diameter of the resulting nanopowder falls within a certain range. To this end, first, the silicon alkoxide is reacted in an alcohol solvent in an alcohol solvent at 35 ° C. to 38 ° C. for 6 to 7 hours to form silica particles, and the silica particles thus obtained have an average particle diameter of 75 nm to 150 nm. It is more preferable to have a range of 80 nm to 90 nm.

The silicon alkoxide is used as a precursor of silica, and examples thereof include tetraethylorthosilicate (TEOS), sodium silicate, and the like, but are not limited thereto.

As the catalyst used in the formation of the silica nanopowder, ammonia water, ammonium bicarbonate, triethanol amine, or the like may be used as a catalyst. For example, the catalyst may be used in an amount of 10 parts by weight to 15 parts by weight based on 100 parts by weight of the silicon alkoxide. . When it is out of the content, there is a problem that the particle size distribution of the silica nanopowder is not uniform, which is not preferable.

An alcohol solvent may be used as a solvent when forming the silica nanopowder, and methanol, ethanol, propanol, etc. may be used as an example, and the content thereof may be used in an amount of 700 parts by weight to 800 parts by weight based on 100 parts by weight of the silicon alkoxide. have. If it is out of the content, it is not preferable because the viscosity of the reaction solution is too large or too small.

The type and content of the raw materials used in the formation of the silica nanopowder are also important, but it is preferable to control the reaction time and the reaction temperature as appropriate. The reaction time of the reaction may be performed for 6 hours to 7 hours, less than 6 hours, the reaction does not occur sufficiently, if more than 7 hours of the particle size distribution of silica nanoparticles due to the production of secondary particles after the production of primary particles It is not desirable because of problems such as nonuniformity. The reaction temperature may be performed at 35 ° C. to 38 ° C., and is less than 35 ° C., which leads to a long reaction time.

The silica nanopowder obtained through the above step forms a silver coating layer in a subsequent step, and the silica nanoparticles obtained in the above step are mixed with the silver ion precursor in an alcohol solvent, and then a reducing agent is added to reduce the silver ion precursor. The silver coating layer is formed on the surface of the silica particles. The process of forming the silver coating layer, the reaction time can be sufficiently coated on the surface of the silica particles by reducing the silver precursor at 35 ℃ to 38 ℃ proceeds for 3 to 4 hours. If it is less than 3 hours, the reaction does not occur sufficiently to form a sufficient coating layer, and if it exceeds 4 hours, the reaction already occurs sufficiently, and thus economical efficiency is lowered, which is not preferable.

Silver nitrate, silver nitrite, silver perchlorate and the like may be used as the silver precursor used in the silver coating layer process, and such silver precursor may be used in an amount of 5 parts by weight to 25 parts by weight based on 100 parts by weight of the silica nanopowder. If the content of the silver precursor is less than 5 parts by weight can not form a sufficient coating layer, if it exceeds 25 parts by weight of the silver coating layer is too thick or unreacted to increase the economical efficiency is not preferable.

As the alcohol solvent used for forming the silver coating layer, methanol, ethanol, propanol, etc. may be used, and may be used in an amount of 2550 parts by weight to 2650 parts by weight based on 100 parts by weight of the silica nanopowder.

When the silver coating layer is formed, conventional reducing agents such as ascorbic acid and sodium borohydride (NaBH _{4) may} be used as the reducing agent used to reduce the silver precursor. 0.1 to 0.5 parts by weight may be used based on 100 parts by weight.

After finishing the silver coating layer process, the product is washed, dried and heat treated according to an appropriate method to remove impurities and unreacted materials.

A silver coating layer may be formed on the silica nanopowder through the silver coating layer forming process as described above, and the thickness of the silver coating layer is formed in the range of 2 nm to 5 nm.

The silver coating layer-containing silica nanopowder obtained by the above-described process is provided with a silver coating layer on the surface thereof to exhibit excellent antimicrobial activity and stability. In particular, the silver is contained in an amount of 2 parts by weight to 9 parts by weight based on 100 parts by weight of silica as a core by the above process. Therefore, the silver coating layer-containing silica nano powder can be used in various fields such as cosmetic compositions, antimicrobial polymer materials, antimicrobial fibers and the like.

In order for the silver coating layer-containing silica nanopowder to properly exhibit antimicrobial activity and stability, it is necessary to form a dispersion having an appropriate concentration. That is, the concentration of the silver coating layer-containing silica nanopowder in the dispersion is preferably formed at a constant concentration, such a concentration may be defined in ppm, the range is preferably from 1,000ppm to 3,000ppm. As the dispersion solvent for forming the dispersion, 1,3-butylene glycol, glycerin, polyethylene glycol, and the like may be used, but is not limited thereto.

The silver coating layer-containing silica nanopowder as described above may be used in various cosmetic compositions, and the cosmetic composition includes components commonly used in addition to the nanopowder. Conventional auxiliaries such as, for example, stabilizers, solubilizers, vitamins, pigments and flavorings, and carriers.

Such a silver coating layer-containing silica nano powder-containing cosmetic composition can prevent the deterioration of the cosmetic as the nano powder exhibits excellent antimicrobial activity and stability, and improves storage and storage stability. The content of the silver coating layer-containing silica nano powder in the cosmetic composition may be used 0.0001% by weight to 0.0005% by weight based on the total weight, 0.0002% by weight to 0.0005% by weight is preferred.

The cosmetic composition according to the present invention comprising the silver coating layer-containing silica nano powder may be prepared in any formulation commonly prepared in the art, for example, solutions, suspensions, emulsions, pastes, gels, creams, Lotions, powders, soaps, surfactant-containing cleansing, oils, powder foundations, emulsion foundations, wax foundations, sprays, and the like, but are not limited thereto. More specifically, it can be manufactured in the form of a soft lotion, a nutritional lotion, a nutritional cream, a massage cream, an essence, an eye cream, a cleansing cream, a cleansing foam, a cleansing water, a pack, a spray or a powder.

When the formulation of the present invention is a paste, cream or gel, animal oils, vegetable oils, waxes, paraffins, starches, trachants, cellulose derivatives, polyethylene glycols, silicones, bentonites, silicas, talc or zinc oxide may be used as carrier components. Can be.

In the case where the formulation of the present invention is a powder or a spray, lactose, talc, silica, aluminum hydroxide, calcium silicate or polyamide powder may be used as a carrier component. Especially, in the case of a spray, a mixture of chlorofluorohydrocarbons, propane / Propane or dimethyl ether.

When the formulation of the present invention is a solution or an emulsion, a solvent, a dissolving agent or an emulsifying agent is used as a carrier component, and examples thereof include water, ethanol, isopropanol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, , 3-butyl glycol oil, glycerol aliphatic ester, polyethylene glycol or sorbitan fatty acid esters.

When the formulation of the present invention is a suspension, a liquid diluent such as water, ethanol or propylene glycol, a suspending agent such as ethoxylated isostearyl alcohol, polyoxyethylene sorbitol ester or polyoxyethylene sorbitan ester, and microcrystals are used as carrier components. Soluble cellulose, aluminum metahydroxy, bentonite, agar or tracant and the like can be used.

When the formulation of the present invention is a surfactant-containing cleansing, the carrier component is an aliphatic alcohol sulfate, an aliphatic alcohol ether sulfate, a sulfosuccinic acid monoester, isethionate, an imidazolinium derivative, a methyltaurate, a sarcosinate, a fatty acid amide. Ether sulfates, alkylamidobetaines, aliphatic alcohols, fatty acid glycerides, fatty acid diethanolamides, vegetable oils, lanolin derivatives or ethoxylated glycerol fatty acid esters and the like can be used.

Hereinafter, the present invention will be described in more detail with reference to the following examples and experimental examples.

However, the following examples are only for illustrating the present invention, and the present invention is not limited by the following examples, and may be changed to other embodiments equivalent to substitutions and equivalents without departing from the technical spirit of the present invention. Will be apparent to those of ordinary skill in the art.

≪ Example 1 >

1 L of 95% -ethanol was added to a 3 L four-neck reactor as a solvent, and 104.17 g of tetraethylorthosilicate was added dropwise thereto, followed by stirring for 30 minutes to allow complete mixing. Subsequently, 9.01 g of distilled water was added thereto, followed by stirring for 30 minutes. Next, 13.6 g of ammonia water was added dropwise as a catalyst, followed by stirring for 6 hours after the reactor temperature was raised to 36 ° C. while stirring. Thereafter, the reaction was washed with water and then vacuum filtered and dried for 12 hours in a 120 ° C. hot air dryer to obtain 30 g of fine silica particles having an average particle diameter of 80 nm.

Next, 1L of 95% -ethanol was added to a 3L four-necked reactor, and 30g of the fine silica particles were dispersed and stirred, while stirring 1.58g of silver nitrate in 3.16g of purified water and slowly dropwise adding 4.74g of an aqueous solution of silver nitrate, and stirred for 3 hours. Then, 0.03 g of sodium borohydride was added as a reducing agent, followed by stirring for 3 hours.

Thereafter, 1 L of distilled water was added, the reaction was washed with water and vacuum filtered. The obtained filter cake was again dispersed in distilled water, vacuum filtered, dried in a 120 ° C. hot air dryer for 12 hours, and then heated up to 300 ° C. step by step for 4 hours to remove impurities and unreacted materials. The silver coating layer had a thickness of 3 nm. 30.7 g of formed silica powder-containing silica powder was obtained.

Subsequently, the silver coating layer-containing silica powder was dispersed at 1000 ppm in a dispersion solvent glycerin to prepare a dispersion.

<Example 2>

1L of 95% -ethanol was added to a 3L four-neck reactor as a solvent, 104.17 g of tetraethylorthosilicate, 9.01 g of distilled water, and 13.6 g of ammonia water were added to the catalyst, followed by stirring to prepare fine silica in the same manner as in Example 1. For the reaction proceeded.

Unlike Example 1, the filtration and drying process of the fine silica was omitted, and immediately after the dropwise addition of the silver nitrate aqueous solution 4.74 g of 1.58 g of silver nitrate dissolved in 3.16 g of purified water as a silver ion precursor, the mixture was stirred for 3 hours. Then, 0.03 g of sodium borohydride was added as a reducing agent, followed by stirring for 3 hours. Thereafter, 1 L of distilled water was added, the reaction was washed with water and vacuum filtered. The obtained filter cake was again dispersed in distilled water, vacuum filtered, dried in a 120 ° C. hot air dryer for 12 hours, and then heated up to 300 ° C. to remove impurities and unreacted materials through a heat treatment for 4 hours to obtain 30.9 g of a silver powder containing silica coating layer. Dispersion preparation process was the same as in Example 1.

<Example 3>

In the step of forming a silver coating layer on the silica particles of Example 1, Example 1 except that 22.5g of silver nitrate aqueous solution dissolved in 7.5g of silver nitrate as a silver ion precursor in 15g of purified water and 0.14g of sodium borohydride as a reducing agent 32.6 g of a silver coating layer-containing silica powder was obtained in the same manner as to prepare a dispersion.

<Example 4>

In the step of forming a silver coating layer on the silica particles of Example 2, Example 2 except that 22.5g of silver nitrate aqueous solution dissolved in 7.5g of silver nitrate as a silver ion precursor in 15g of purified water and 0.14g of sodium borohydride as a reducing agent 32.9g of a silver coating layer-containing silica powder was obtained in the same manner as to prepare a dispersion.

Scanning electron microscopy (SEM) photographs of the silver coating layer-containing silica powders obtained in Examples 1 to 4 are shown in FIGS. 1 to 4. It can be seen from the above FIGS. 1 to 4 that silver is coated on the silica surface.

In order to know the silver content of the silver coating layer-containing silica powder obtained in Examples 1 to 4, the analysis results of the inductively coupled plasma (ICP, OPTIMA 5300DV, PerkinElmer, USA) are shown in Table 1.

Silver content analysis result of silica powder containing silver coating layer Example 1 Example 2 Example 3 Example 4 Ag concentration (% by weight) 2.3 2.8 8.1 8.9

Experimental Example 1 Antibacterial Activity Test

Paper disk method (Paper disk (8 mm) method) was used to examine the antimicrobial activity spectrum of the powders and dispersions prepared in Examples 1 to 4. Test strains include Pseudomonas aeruginosa (ATCC 9027), Staphylococcus aureus (ATCC 6538), E. coli (Escherichia coli: ATCC 10536), Candida albicans (ATCC 10231), Black fungus (Aspergillus niger: 16404).

1) Antimicrobial Activity Test of Silica Powder Containing Silver Coating Layer

The antimicrobial test was prepared by incubating the bacteria in Lesin broth for 24 hours at 37 ° C. In the case of yeast and mold, bacteria were inoculated into YM broth and incubated at 25 ° C. for 2 days. After incubation, the cells were diluted in sterile saline to spread the bacteria on each agar plate medium at a germ concentration of about 1 × 10 ⁶ CFU, and the yeasts and molds were plated on each agar plate medium at a germ concentration of about 1 × 10 ⁵ CFU. It was. Each test sample was dissolved in ethanol at a concentration of 0.02% (w / v), absorbed by 50 ml, and placed on a dry sterile 8 mm paper disc. Then, bacteria were incubated at 37 ° C. for 24 hours, and yeast and mold were incubated at 25 ° C. for 2 days, and then the size of the clear zone around the disc was measured and described in Table 2 below.

Zona size measurement result Strain name unit Example 1 Example 2 Example 3 Example 4 S. aureus mm + 8.5 10.5 10.5 P. aeruginosa mm + 8.5 12.5 13.5 E. coli mm 8.5 9.0 11.5 13.0 C. albicans mm - - 9.0 9.5 A. niger mm - - 10.0 10.0

As shown in Table 2, Examples 3 and 4 showed excellent antimicrobial activity against all the bacteria. Antimicrobial activity was found to be proportional to the silver content as shown in Table 1 above.

2) Antimicrobial Activity Test of Silica Dispersion Containing Silver Coating Layer

In the antimicrobial activity test of the dispersion, a dispersion prepared by dispersing the silica powder containing the silver coating layer in glycerin at a concentration of 1000 ppm was used. The dispersion was diluted with sterile water at a concentration of 0.2% (v / v) and loaded in a paper disk, followed by the same method as the antibacterial activity test of the powder, except that the mixture was left at room temperature for 5 minutes. .

Antibacterial activity test result Strain name unit Example 1 Example 2 Example 3 Example 4 S. aureus mm + + 11.5 11.5 P. aeruginosa mm 8.5 8.5 13.0 14.0 E. coli mm 8.5 9.0 12.0 12.5 C. albicans mm - - 9.0 9.0 A. niger mm - - 10.5 10.0

As shown in Table 3, the antimicrobial activity of the dispersion solution was the same as in the case of powder.

Experimental Example 2 Antibacterial Activity Test

In order to evaluate the antimicrobial activity of the powders and dispersions prepared in Examples 1 to 4, the inhibitory force was measured for each concentration to determine the minimum inhibitory concentration. The dispersion was prepared by dispersing in glycerin at a concentration of 1000 ppm. The strain used was the strain used in the antimicrobial activity test of Experimental Example 1, and the culture and preparation process for each strain was performed in the same manner as in Experimental Example 1.

More specifically, each sample to be tested is diluted to an appropriate concentration in sterile water, and each concentration of diluent is added to 2 ml each of the sterilized petri dishes. After 2 ml each, sterilize each petri dish, and add Resin agar medium and YM agar medium maintained at 50 ° C, 18 ml each of sample solution and medium: sample solution = 9: 1 ratio, mix well, and then stand still. Solidified.

When the medium is solidified, each of the cultured test bacteria is inoculated into each petri dish at a final concentration of about 1 to 5 x 10 ⁶ CFU for bacteria, and about 1 to 5 x 10 for yeast and mold. Each petri dish was inoculated with a bacterial concentration of ⁵ CFU. Bacteria in each petri dish were cultured at 37 ° C., yeast and mold for 5 days at 25 ° C., and then colony formation was visually observed. Table 4 shows the progress of the antimicrobial agent concentration of the plate that inhibits the growth of bacteria as the minimum inhibitory concentration (MIC).

Minimum inhibitory concentration result division Minimum Inhibitory Concentration (ppm) S. aureus P. aeruginosa E. coli C. albicans A. niger Example 1 powder 25 10 10 35 20 Dispersion 450 250 200 500 400 Example 2 powder 20 10 10 30 20 Dispersion 400 250 200 500 400 Example 3 powder 3 2 2 3 3 Dispersion 100 50 50 150 100 Example 4 powder 3 2 2 3 3 Dispersion 100 50 50 150 100 Comparative Example 1 Methyl paraben 800 1000 800 1000 600 Comparative Example 2 Ethyl paraben 500 800 600 800 400

As shown in Table 4, Examples 1 and 2 showed a relatively weak antimicrobial activity because the coating amount of silver is smaller than that of Examples 3 and 4. In addition, the silver coating layer-containing silica powder and dispersion showed much stronger antimicrobial activity than that of the parabens presented in Comparative Examples. Therefore, when the powder and dispersion are formulated into a cosmetic composition, it is possible to store various cosmetics for a long time without excluding chemical preservatives that can cause skin irritation and allergic reactions.

<Examples 5 to 8> Lotion Base Preparation

A lotion base including the dispersion of Example 4 and a conventional chemical preservative, which showed excellent effects in the experiment, were prepared. The cosmetics used in the experiment is in the form of an emulsion cosmetic liquid, the composition is shown in Table 5.

Emulsifying Cosmetic Composition division ingredient weight% Oil Cetyl alcohol 1.0 Malad 0.5 Waserin 2.0 Squalene 6.0 Dimethyl Polysiloxane 2.0 Alcohol ethanol 5.0 Moisturizer glycerin 4.0 1,3-butylene glycol 4.0 Surfactants POE (10) Monooleic Acid Ester 1.0 Glycerol Monostearic Acid Ester 1.0 Mucus Queen's seed extract (5% aqueous solution) 2.0 antiseptic Silica dispersion or chemical preservative containing silver coating layer 0.1-0.5 Colorant Dye (1% aqueous solution) 0.001-0.003 incense 0.001-0.003 Distilled water to 100

First, a moisturizer and a colorant are added to distilled water in order to manufacture a water-part, and it heat-adjusts to 70 degreeC. Next, a surfactant and an antiseptic are added to the oil with an oil phase part, and it heat-adjusts to 70 degreeC. This is first added to the water phase to preliminary emulsification. Queen's seed extract and ethanol were added thereto, stirred, and uniformly emulsified in a homomixer, followed by degassing, filtration and cooling to prepare a cosmetic liquid.

In the preservative content of Table 5, according to the composition of the following Table 6, a lotion base containing the dispersion amount of Example 5 to Example 8, Comparative Example 3 containing a chemical preservative, and a comparison without adding a preservative Example 4 was prepared.

Preservative Content ingredient Example 5 Example 6 Example 7 Example 8 Comparative Example 3 Comparative Example 4 Dispersion 0.1 wt% - - - - - - 0.2 wt% - - - - - - 0.3 wt% - - - - - - 0.5 wt% - - Methyl paraben - - - - 0.4 wt% - Profile paraben - - - - 0.2 wt% - Phenoxy ethanol - - - - 0.4 wt% - Distilled water - - - - - 1 wt%

Experimental Example 3 Antiseptic Test in Formulation

The antiseptic activity of the lotion bases prepared in Examples 5 to 8 and Comparative Examples 3 and 4 was examined to determine the antiseptic power in the formulation containing the silica dispersion solution containing the silver coating layer. Preservative effectiveness testing is very important for product safety and consumer acceptance as a means of determining the minimum concentration of preservatives needed to safely preserve the product without causing skin irritation to the consumer. To measure the preservation of cosmetics, USP and CFA are widely used. This test method used the microbial guidelines of the Cosmetic, Toiletry and Fragrance Association (CTFA).

The test strain used the same strain as Test Example 1. Resin agar medium was inoculated with three bacteria, YM agar medium was inoculated with yeast and mold. Bacteria were incubated for 24 hours to 72 hours in a culture vessel at 37 ° C., yeast and mold at 25 ° C., respectively, and then suspended in 0.8% physiological saline.The bacteria were about 1 × 10 ⁶ CFU, and yeast and mold were 1 × 10 ⁵ CFU. Was made. 10 g of each lotion base sample of Examples 5 to 8 and Comparative Examples 3 to 4 were inoculated with 100 ml of three bacterial suspensions and two yeasts, respectively. Afterwards, each inoculated sample is stored at room temperature, and 1 g of sample is collected under sterile operation every 1, 2, 3, 7, 14, 21, and 28 days, and diluted with dilution. Resin agar medium, yeast and fungi were placed on YM agar medium and counted after incubation for 24 to 72 hours at 37 ° C and 25 ° C, respectively. Due to the effectiveness of the antiseptic force, bacteria should be reduced by at least 99.9% of the strains within 7 days of inoculation, and have no growth during the test period. In addition, yeast and mold should be reduced by at least 90% of strains within 7 days of inoculation and should not grow during the test period. The results are shown in Tables 7 and 8 below.

Antiseptic test results for bacteria division Bacterial Count (cells / ㎖) 3 days 1 week 2 weeks 3 weeks 4 Weeks Example 5 2 × 10 ² 3 × 10 ² 2 × 10 ² <100 0 Example 6 <100 <100 0 0 0 Example 7 <100 0 0 0 0 Example 8 <100 0 0 0 0 Comparative Example 3 2 × 10 ² <100 0 0 0 Comparative Example 4 2 × 10 ⁶ 3 × 10 ⁵ 4 × 10 ⁴ 2 × 10 ⁵ 3 × 10 ⁴

As shown in Table 7, in Example 6-8 prepared with a lotion base formulation, it was shown to have an antiseptic activity equivalent to or better than that of Comparative Example 3 in which a conventional chemical preservative was prescribed in killing bacteria.

Antiseptic test results for fungi division Fungal water (cells / ㎖) 3 days 1 week 2 weeks 3 weeks 4 Weeks Example 5 2 × 10 ² 3 × 10 ² 2 × 10 ³ 2 × 10 ² <100 Example 6 <100 <100 0 0 0 Example 7 <100 0 0 0 0 Example 8 <100 0 0 0 0 Comparative Example 3 6 × 10 ² <100 <100 0 0 Comparative Example 4 2 × 10 ⁵ 8 × 10 ⁴ 5 × 10 ⁴ 6 × 10 ⁴ 8 × 10 ³

Table 8 also shows the same results as in the case of Table 7. Therefore, the content of the silver coating layer-containing silica in the formulation is considered to be 0.0002 ~ 0.0005% by weight.

1 is a SEM image of the microstructure of the silver coating layer-containing silica powder according to Example 1 of the present invention

2 is a SEM image of the microstructure of the silver coating layer-containing silica powder according to Example 2 of the present invention

3 is a SEM image of the microstructure of the silver coating layer-containing silica powder according to Example 3 of the present invention

4 is a SEM image of the microstructure of the silver coating layer-containing silica powder according to Example 4 of the present invention

Claims (9)

delete delete A first step of reacting silicon alkoxide in an alcohol solvent at 35 ° C. to 38 ° C. for 6 to 7 hours in the presence of a catalyst to form silica particles having an average particle diameter of 75 nm to 150 nm; And And mixing the silica particles with the silver precursor in an alcohol solvent, and then adding a reducing agent to reduce the silver precursor to form a silver coating layer on the surface of the silica particles. Method for producing a silica nano powder containing a coating layer. The method of claim 3, The catalyst is any one selected from the group consisting of ammonia water, ammonium bicarbonate and triethanol amine, characterized in that 10 parts to 15 parts by weight of the catalyst is used based on 100 parts by weight of the silicon alkoxide in the first step. Method for producing a silica nano powder containing a coating layer. The method of claim 3, In the first step, the alcohol solvent is 700 parts by weight to 800 parts by weight based on 100 parts by weight of the silicon alkoxide, and in the second step, the alcohol solvent is 2550 parts by weight of the alcohol solvent based on 100 parts by weight of the silica particles. To 2650 parts by weight is used, the silver coating layer-containing silica nano powder production method. The method of claim 3, The silver precursor is any one selected from the group consisting of silver nitrate, silver nitrite and silver perchlorate, wherein the silver precursor is used in an amount of 5 parts by weight to 25 parts by weight based on 100 parts by weight of the silica particles. , Silver coating layer containing silica nanopowder production method. The method of claim 3, The reducing agent includes ascorbic acid or sodium borohydride, and in the second step, 0.1 parts by weight to 0.5 parts by weight of the reducing agent is used based on 100 parts by weight of the silica particles. Manufacturing method. delete delete

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