KR101642453B1 - Method for producing sericite with high photocatalytic activity of visible light, high opacity and antimicrobial property and its sericite - Google Patents

Abstract

The present invention provides a colloidal silver and a titanium dioxide source independently of each other using a sol-gel method. In this process, silver nano solution and phosphoric acid are simultaneously obtained In this way, the silver mixed solution prepared in this way and the sericite mixed with the prepared titanium dioxide source are crushed and crushed after the slurry is mixed, and silver, silver phosphate and titanium dioxide (TiO ₂ ) Coated on the surface of a thin layer of the optical fiber, which is excellent in high optical activity, hiding power and antimicrobial activity in a visible light region not irradiated with sunlight.

Description

TECHNICAL FIELD The present invention relates to a method for producing a sericite having high optical activity, a hiding power, and a antibacterial activity in a visible light region, and a sericite produced by the method and a sericite produced by the method.

The present invention provides a colloidal silver and a titanium dioxide source independently of each other using a sol-gel method. In this process, silver nano solution and phosphoric acid are simultaneously obtained In this way, the silver mixed solution prepared in this way and the sericite mixed with the prepared titanium dioxide source are crushed and crushed after the slurry is mixed, and silver, silver phosphate and titanium dioxide (TiO ₂ ) Coated on the surface of a thin layer of the optical fiber, which is excellent in high optical activity, hiding power and antimicrobial activity in a visible light region not irradiated with sunlight.

Recently, damage by various kinds of bacteria and viruses has been continuing. Staphylococcus, Salmonella, which causes vomiting and diarrhea, and Escherichia coli, a causative organism of food poisoning, are living in daily life. Although many antibiotics and extracts have been discovered and developed so far to prevent and treat these damages, the emergence of antibiotic resistant strains resistant to conventional antibiotics has caused the disease relief by human microbial infection to suffer again. Furthermore, as the ability and duration of these microorganisms to acquire tolerance is accelerated, research and development of new antibiotics with mechanisms that are different from conventional antibiotics are needed.

Human beings have long been using antimicrobial agents or medicinal herbs for the treatment of infectious diseases caused by microorganisms, and silver (Ag) is one of them. Silver is harmless to the human body and has no toxicity. It is known to kill more than 650 kinds of harmful bacteria by inhibiting various metabolic functions in the microorganism. In addition to the inhibition of metabolic functions, it is also known that the silver (Ag +) emitted by the metal (Ag +) exerts an antibacterial and bactericidal action by affecting the reproductive function of the microorganism due to the electrical ability of the silver ion. The ability of microorganisms to inactivate silver has been studied since 1869, and many researchers have been conducting researches to date. As a result, the number of microorganisms resistant to other antibiotics is small.

In the case of sterilization and disinfection using silver (Ag ⁺ ) ions, research has been carried out for decades, and a strong and broad antibacterial activity can be seen from the existing studies. A variety of explanations have been proposed to understand the mechanism of antimicrobial activity of silver ions. The most widely known is that S-Ag reacts with the -SH group of cysteine, which is one of the amino acids constituting proteins such as enzymes, And is a mechanism for inactivating microorganisms. In addition, it can induce the production of reactive oxygen species (ROS) during the metabolism of microorganisms, and it can activate the microorganisms by releasing K ⁺ ions in the cytoplasmic membrane of microorganisms, And that it inhibits microbial cell division by directly reacting with a base present in the cell. However, the inactivation mechanism for DNA degradation is reported to be mainly due to the above-mentioned mechanisms, since silver ions (Ag ⁺ ) are likely to react with proteins first when they are introduced into microorganisms. Research on silver ions has been conducted on synergistic effects with various antimicrobial substances such as hydrogen peroxide (H ₂ O ₂ ) and copper ions as well as synergistic effects on various wavelengths of light as well as these mechanisms.

Tartar dioxide (TiO ₂ ) is a colorless or white powder with no odor or taste. Formula is TiO _2. It does not dissolve in water, hydrochloric acid, dilute sulfuric acid, alcohol and other organic solvents. It is a white pigment which has a very high hiding power which is insoluble in acids other than hot concentrated sulfuric acid. There are rutile type, anatase type, brookite type, mainly anatase type.

Titanium dioxide is a tiny, odorless white powder that is bound to one of the transition metal titanium atoms and two oxygen atoms. Titanium dioxide has a very high oxidizing power and a large negative power, which is insoluble in almost all solvents. It also exhibits a very high refractive index anisotropy and high scattering properties. It is a very stable substance and does not react biologically, which is harmless to the environment and human body. In addition, the structure of titanium dioxide exists in the form of a homogeneous polyphase of brookite, anatase, and rutile, has a large antimicrobial action due to its high oxidizing power, has a malodor removing action and sterilizing action, and is an insulator. Therefore, titanium dioxide is used as an ultraviolet screening agent and cosmetics, and is widely used as a white paint such as paints, glaze, ink, correction liquid, paint and the like. It is also used as a food additive by sharpening the color of food, used as an antibacterial agent, odor removal and disinfectant, and used as a semiconductor material, a photocatalyst, a solar cell and a coating material.

In addition, titanium dioxide as a photocatalyst must first be stabilized in order to be used as a photocatalyst, and should have excellent ability to absorb light and oxidize other substances. Titanium dioxide exhibits excellent compatibility in this respect, and it also has the great advantage of non-toxicity that does not affect organisms. Also, photocatalytic decomposition of an organic material without dissolving in an aqueous solution, an acid or a base solution is also suitable as a photocatalyst. The energy bandgap of titanium dioxide is 3.0 ~ 3.2eV, which is relatively large, so it absorbs light in the ultraviolet region and acts as a photocatalyst. Particularly, light having a wavelength of 385 nm is used. However, if it acts as a photocatalyst by mixing with other dyes or colored organic matter, it can act as a photocatalyst even in the light of the visible light region.

Sericite is a generic term for sericite, which is a dense or fine scaly muscovite. The word 'sericite' comes from the Greek word silk. It is a monoclinic system, which has three crystal axes of a, b, and c with different lengths and has two orthogonal axes a and b that are orthogonal to each other but obliquely intersect the a axis The right and left axes are orthogonal to each other and the front and rear axes are orthogonal to the left and right axes but obliquely intersect with the up and down axes. On the other hand, β is 90 ° as in Hwangbyeol, and its appearance is the same as that of orthorhombic, but it is structurally monoclinic ), And it is white or grayish white with pearl luster. It was originally referred to as the main component minerals of crystalline schist, especially sericite schist. In today's hydrothermal process, however, the formation of metallic mineral deposits or non-metallic mineral deposits by a thermal aqueous solution containing a large amount of volatile components, , The most important of the hydrothermal processes is the formation of deposits. The resulting deposits are called hydrothermal deposits.

Metal deposits belonging to hydrothermal deposits include gold, silver, copper, lead, zinc, tin, manganese, and tungsten. Non-metallic deposits include barite, gypsum, pyrophyllite, fluorite, kaolin and sericite. The hydrothermal alteration effect of the various components contained in the thermal aqueous solution alternating with some of the parent rock components is silicification, chlorite crystallization, carbonation, thinning and claying. Hot springs are a clay-like fine muscovite formed by a thermal water solution mixed with ground water and rising to the surface. The chemical composition is almost the same as that of muscovite, but potassium (K) is generally less than muscovite and has a slightly higher water content.

The sericite is produced as a secondary alteration such as feldspar, cordierite, and ore. It is a regional metamorphism (action by the pressure and temperature of the crust, which recrystallizes existing rocks over a large area and produces metamorphic rocks. The rocks produced by the metamorphic process are crystalline schists and gneisses, and are characterized by a remarkable convenience and streak structure. The most important predisposing factors in the metamorphic process are temperature and pressure. When the temperature and the pressure rise in a wide range within the rock, the equilibrium between the minerals composing the rock is broken and the reaction occurs between the minerals, resulting in a new combination of minerals. .

As described above, the sericite has various uses due to its excellent far infrared effect and deodorizing effect. Styrofoam is a highly clay mineral, but it contains K ₂ O, which is a very useful mineral that plays a role both as a plasticizer and flux. It is used for raw materials for ceramics and welding rods. Its sericite has fine particles and scales Because it is easy, it is used in textile industry, filler, and abrasive as well as raw materials such as paints, pigments, medicines and cosmetics.

In particular, among the various industrial fields, silver inorganic antibacterial agent is used to provide antibacterial power while providing low toxicity. Since the silver nano solution prepared by sol-gel method has a very small particle size of silver and has a large specific surface area, However, since it is a colloidal silver antimicrobial dispersed in water, it can not be used in fields having no affinity with aquatic system, and there are many disadvantages in using colloidal silver nano solution in water because it is very expensive.

In addition, titanium dioxide for providing hiding power and photocatalyst can be widely used as a filler in various industrial fields without toxicity, and is widely used as a photocatalyst in water quality and atmospheric environment, but its price is higher than other minerals It is difficult to provide the photocatalyst with the function of photocatalyst because the photocatalytic function can not be performed because the photocatalytic function is not performed in the visible light region where sunlight is not irradiated, Lt; / RTI >

Therefore, it is necessary to study the sericite with highly active photocatalytic function, as well as to exhibit the antibacterial ability and hiding power function which are not affected by the application fields other than water or water.

In the prior art related to sericite having antimicrobial activity, hiding power, and photocatalytic function, Korean Patent Publication No. 2002-0062150 discloses a method of mixing titanium dioxide and sericite on a powdery basis; The titanium dioxide and the sericite mixture are vibrated to dry-coat titanium dioxide on the surface of the sericite, thereby providing a method of manufacturing a cosmetic composition having a titanium dioxide-coated sericite.

However, in the titanium dioxide coating method, it is suggested that the titanium dioxide and the sericite mixture are vibrated at a room temperature state without a constant temperature, In order to provide a physical bonding force for coating with sericite, it is necessary to sinter at a temperature of 500 ° C or higher for a suitable time to coat the surface of the sericite with titanium dioxide, And only the technical constitution related to the coating of titanium dioxide to have a cosmetic composition is limited.

Korean Patent Publication No. 2012-0043459 discloses a method of adsorbing and deodorizing harmful substances such as radon and various volatile organic compounds including radon and aldehyde emitted from cement and increasing the emission of far infrared rays and anions to improve the health of residents The present invention relates to a composition for additive for building interior and exterior materials and a method for producing a mortar for plaster containing the composition. However, the composition contains 40 to 60 wt% of sericite to improve the health of the human body by generating far- , And titanium dioxide, which is excellent in hiding power, is not included when used as an interior and exterior material of a building, so that the workability is very low due to the necessity of painting several times as the shape or background of the base surface appears, The problem still exists.

Korean Patent Publication No. 2011-0099813 proposes the surface modification of titanium dioxide on the surface of sericite to improve the ultraviolet shielding function of cosmetics and to manufacture functional cosmetics emitting far infrared rays, In the case of the present invention, in the case of the present invention, by using the horizontal rotation vibration of 2500 rpm and the physical pressure of the vertical axis, the surface of the sericite particles is coated with titanium dioxide The titanium dioxide is not uniformly surface-treated on the sericite particles, so that the objective ultraviolet ray shielding function and the far-infrared ray can not reach the radiation function. have.

Korean Patent Laid-Open Publication No. 2013-0057280 discloses a curable resin composition comprising 20 to 60 parts by weight of a curable resin solid, 0.1 to 10 parts by weight of a silver nanoparticle colloid solution, 0.1 to 25 parts by weight of a metal oxide fine particle, and a silicate compound produced by hydrolyzing a silicate compound with excess water 1 to 25 parts by weight of a water-soluble silicate compound, and a resin composition and a functional film having an antimicrobial effect. However, this is because when the concentration of silver (Ag) in the silver nanoparticle colloid solution is not clearly described, To 10 parts by weight, it is not only an unclear technique but also provides a resin having an antibacterial effect in which a colloidal silver nano solution is simply mixed with a resin.

So far, the sericite provided for high hiding power and antimicrobial power has been limited in satisfying all the functions of hiding power, antibacterial power and photocatalyst. Therefore, there is a need to provide a sericite that can satisfy both hiding power, antibacterial power, and efficiency as a photocatalyst.

Korean Unexamined Patent Publication No. 2012-0062150 Korean Unexamined Patent Publication No. 2012-0043459 Korean Published Patent Application No. 2011-0099813 Korean Laid-open Patent Publication No. 2013-0057280

(I) preparing a silver salt solution and a titanium salt solution, respectively;

(Ii) the silver salt solution is prepared as a colloidal silver solution by a sol-gel method, and the titanium salt solution is hydrolyzed with an alkali or an acid solution to prepare a titanium salt precipitate or a colloidal titanium solution Thereby producing a coating solution for coating the sericite, respectively; And

(Iii) applying and mixing the sericite to a coating solution obtained by mixing a silver salt solution of colloidal silver with a solution of a titanium salt precipitate or a colloidal titanium solution, and surface-treating the sericite surface,

The colloidal silver in the step (ii) may be prepared by adding silver salts to distilled water, diluting the concentrate with a reducing agent, reducing the concentrate with phosphate, adding a nano-silver suspension, And a mixed solution obtained by simultaneously obtaining silver phosphate,

The titanium salt precipitate is provided with titanium hydroxide [Ti (OH) ₄ ] obtained by adding an inorganic titanium salt to water and dropwise adding an alkali solution while stirring, washing with water and filtering,

The colloidal titanium solution is obtained by adding organic titanium to an alcohol-based solvent and supplying water and acid, stirring the mixture, and aging the mixture.

It is an object of the present invention to provide a sericite having high optical activity, hiding power and antibacterial activity in a visible light region produced by the above method.

In order to solve the above-described problems, the present invention provides a method for producing a colloidal silver-silver mixed solution by coating a surface of a sericite with a silver colloidal silver and a titanium source by a sol- Silver phosphate, which can provide high photoactivity in the visible light region during the process, can be obtained simultaneously with the nano-silver suspension to form silver (Ag), silver phosphate, and titanium dioxide (Ti ₂ O) can be easily coated on the sericite to provide a multifunctional sericite that is excellent in hiding power, antibacterial activity, ultraviolet ray region, and photoactive in the visible light region.

(I) preparing a silver salt solution and a titanium salt solution, respectively;

(Ii) the silver salt solution is prepared as a colloidal silver solution by a sol-gel method, and the titanium salt solution is hydrolyzed with an alkali or an acid solution to prepare a titanium salt precipitate or a colloidal titanium solution Thereby producing a coating solution for coating the sericite, respectively; And

(Iii) applying and mixing the sericite to a coating solution obtained by mixing a silver salt solution of colloidal silver with a solution of a titanium salt precipitate or a colloidal titanium solution, and surface-treating the sericite surface,

The colloidal silver in the step (ii) may be prepared by adding silver salts to distilled water, diluting the concentrate with a reducing agent, reducing the concentrate with phosphate, adding a nano-silver suspension, And a mixed solution obtained by simultaneously obtaining silver phosphate,

The titanium salt precipitate is provided with titanium hydroxide [Ti (OH) ₄ ] obtained by adding an inorganic titanium salt to water and dropwise adding an alkali solution while stirring, washing with water and filtering,

The colloidal titanium solution is obtained by adding organotitanium to an alcoholic solvent, supplying water and acid, stirring and aging.

The present invention relates to a colloidal silver colloidal silver solution containing silver phosphate and titanium hydroxide [Ti (OH) ₄ ] that can provide photoactivity even in the visible light region obtained by the sol-gel method And coating them on the surface of the sericite to provide the functionality of the sericite itself as well as the functionality of the silver nano solution alone or titanium dioxide alone, So that the antibacterial and hiding power can be exerted equally.

It is also possible to provide a highly active photocatalytic sericite capable of purifying the atmosphere and water quality in the visible light region where sunlight is not irradiated.

Accordingly, the functionalistic sericite having photocatalyst, antibacterial power, and hiding power according to the present invention can be used in various fields such as environmentally friendly organic materials and building interior materials, environmentally friendly livestock materials, functional cosmetics, water treatment environmental materials, environmentally friendly wallpaper, eco-friendly cement, fiber, cement photocatalyst, Air fresheners, air fresheners, etc., in addition to fertilizer and livestock feed.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a process drawing briefly showing a method for producing a sericite according to the present invention.

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

The 'sol-gel method' according to the present invention is a method in which colloid particles are dispersed to form a sol state having fluidity, that is, a semi-solid such as tofu and agar in a suspension state, And the transition to the lost gel (gel).

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing a process for producing a sericite according to the present invention. FIG.

Specifically, when the method for producing the sericite according to the present invention is shown for each step,

(I) preparing a silver salt solution and a titanium salt solution, respectively;

(Ii) the silver salt solution is prepared as a colloidal silver solution by a sol-gel method, and the titanium salt solution is hydrolyzed with an alkali or an acid solution to prepare a titanium salt precipitate or a colloidal titanium solution Thereby producing a coating solution for coating the sericite, respectively; And

(Iii) supplying and mixing the sericite to a coating solution obtained by mixing titanium silver salt precipitate or colloidal titanium solution with the silver colloidal silver, and surface-treating the sericite surface;

(Iv) a drying step of removing water from the surface-treated slurry-form sericite;

(V) a crushing step of crushing the sericite in a dry state;

(Vi) a sintering step of sintering the crushed material; And

(Iii) a cooling step of cooling the sintered pulverized product.

In this case, the silver colloidal silver is diluted by adding silver salts to distilled water, reduced by adding a reducing agent, and then added with a phosphate solution to prepare a nano-silver suspension and silver phosphate. Are simultaneously prepared for mixing,

The titanium salt precipitate is titanium hydroxide [Ti (OH) ₄ ] obtained by adding an inorganic titanium salt to water, adding an alkali solution dropwise thereto while stirring, washing with water and filtering,

The colloidal titanium solution is obtained by adding organic titanium to an alcohol-based solvent, supplying water and an acid, stirring, and aging.

Hereinafter, the method for producing the sericite according to the present invention will be described step by step.

In the present invention, a silver salt solution and a titanium salt solution are respectively prepared (step (i)) to prepare a silver and titanium dioxide source coated on a sericite, and the silver salt solution is subjected to a sol- As the solution, the titanium salt solution is prepared separately as the titanium hydroxide [Ti (OH) ₄ ] or the colloidal titanium solution (step (ii)).

Specifically, before performing the sol-gel method, silver salts are first diluted with distilled water (step (i)).

The silver salt (silver slats) is silver nitrate (AgNO _3), nitrous acid is (AgNO _2), acetic acid (CH ₃ CO ₂ Ag), and the acid is (Ag ₂ CO ₃₎ is preferably used at least one member selected from. Here, the silver carbonate (Ag ₂ CO ₃ ) is insoluble in distilled water, and the dissolved solution is used as the silver salt of step (i) after supplying nitric acid (HNO ₃ ) or acetic acid (CH ₃ COOH) . It is also advantageous to dilute the silver to be diluted in the distilled water to a concentration of 50 ppm to 0.4 wt%, more preferably 500 ppm to 0.15 wt%.

When the silver is diluted to a concentration of less than 50 ppm, the concentration of the reducing agent for performing the sol-gel process step is very low, so that a large amount of management is required to prepare a colloidal silver nano solution, and a functionalized sericite containing high silver It is necessary to add a large amount of silver nano solution at a low concentration of less than 50 ppm. Therefore, it takes a lot of time and expense in the subsequent process including the drying step. When the silver nanoparticles are diluted in an atmosphere capable of maintaining a high concentration exceeding 0.4 wt% There is a problem in that the low specific surface area of silver may degrade the antimicrobial effect due to the formation of silver of large particles by collecting silver of fine particles by the coagulation phenomenon of the colloid-like highly dispersed silver (Ag) formed by the sol-gel method It is preferable to dilute the solution at the ratio of the above-mentioned concentration.

In addition, it is preferable to dilute silver salts by using distilled water in which chloride ions, sulfate ions, fluorine ions, and phosphate ions are not present. The silver salts supplied to the water are combined with anions other than nitrate ions and nitrate ions In order to form insoluble precipitates, it is preferable to use distilled water in which no anion is present in order to prepare a normal colloidal nano-solution.

In this way, a silver nano-silver suspension exhibiting antibacterial activity using a sol-gel method is produced by slowly supplying a reducing agent while stirring silver salts diluted and dissolved in distilled water, and at the same time, The concealing power of the titanium dioxide or the reducing agent and the phosphate are added to the photocatalyst to simultaneously form silver phosphate which can enhance the light activity in the visible light region (step (ii)).

The reducing agent is preferably at least one selected from sodium borohydride (NaBH ₄ ), citric acid, ascorbic acid, tannic acid, and hydrazine hydrate (N ₂ H ₄ H ₂ O) .

In this case, the reducing agent is used in an amount of 1 mole of reducing agent per 100 moles of silver metal to reduce the amount of the silver salt. The nano-silver suspension and the silver phosphate is supplied at a rate of 0.55 mol to 0.99 mol based on the silver salts corresponding to 1 mol, 55 to 99% of all the silver salts are dissolved in the colloid Silver phosphate (Ag ₃ PO ₄ ) which can increase the photoactivity in the ultraviolet region by supplying 0.01 to 0.45 moles of phosphate to the nano-sized phosphorus is reduced to silver metal, To form a colloidal silver nano solution contained therein.

The phosphate for generating phosphoric acid may be phosphoric acid (H ₃ PO ₄ ), sodium phosphate (NaH ₂ PO ₄ ), dibasic sodium phosphate (Na ₂ HPO ₄ ), sodium phosphate dibasic (Na ₃ PO ₄ ) It is preferable that at least one selected from potassium phosphate monobasic (KH ₂ PO ₄ ), potassium phosphate dibasic (K ₂ HPO ₄ , and potassium tertiary phosphate (K ₃ PO ₄ ) is selected.

Next, in order to prepare a colloidal titanium solution, the inorganic titanium salt is first diluted in water or the organic titanium salt is diluted in an alcohol solution (step (i)).

Specifically, titanium hydroxide [Ti (OH) ₄ ] is formed by dropwise adding at least one diluted alkali solution selected from among ammonia water, sodium hydroxide, and potassium hydroxide while stirring the inorganic titanium salt to water, Alternatively, organic titanium is put into an alcoholic solvent, and water and an acid are supplied and then stirred at a high speed to hydrolyze to form a colloidal titanium solution, which is then aged to provide (step (ii)).

In the case of using the inorganic titanium salt, at least one selected from among titanium tetrachloride (TiCl ₄ ), titanyl sulfate (TiOSO ₄ ), and titanium sulfate [Ti ₂ (SO ₄ ) ₃ ] desirable.

Titanium tetraisopropoxide (TTIP) is preferably used when the organic titanium is used, and at least one selected from ethanol, butanol, methanol, and 2-propanol may be used as the alcohol-based solution.

In this case, the amount of titanium (Ti) diluted in the water or alcohol-based solution is preferably 500 ppm to 15 wt%, more preferably 1.0 to 8.5 wt%, and most preferably 2.5 to 5.5 wt%.

When the concentration of the titanium is diluted to a concentration of less than 500 ppm, it is necessary to apply a large amount of a solution of a titanium salt diluted to a low concentration or to perform a coating step several times in order to provide a high hiding power or an excellent functioning sericite for shielding ultraviolet rays It is disadvantageous in that it takes much time and expense to be in the process of drying or in other processes and when the concentration of titanium is diluted to a concentration exceeding 15% by weight, normal hydrolysis does not occur in the sol- It is preferable to dilute the titanium dioxide in the ratio of the above-mentioned concentration since it takes a long time to make a source of titanium dioxide.

In addition, the solution for diluting the inorganic titanium salt and the organic titanium salt may be prepared as a titanium source for generating titanium dioxide by using a hydrolysis method.

Specifically, in order to hydrolyze the inorganic titanium, when the diluted inorganic titanium salt is stirred, one or more diluted alkali solutions selected from ammonia water, sodium hydroxide, and potassium hydroxide are supplied to prepare titanium hydroxide [Ti (OH) ₄ ] And the solution is flushed with water several times to prepare a solution with minimized impurities capable of providing hiding power.

Next, in order to hydrolyze the organotitanium, water and acid which are hydrolyzed to an alcohol-based organic titanium solution are supplied and agitated at a high level, (Step (ii)) that can be coated with titanium dioxide.

The silver niobium solution and the titanium solution prepared in this way are supplied to the sericite, mixed and coated with silver and titanium dioxide (step (iii)) to maintain a uniform distribution on the surface of the sericite For this purpose, the present mixing step may be a slurry or a solid component in which a solution of a sericite, a silver nano solution and a titanium source are uniformly mixed together without any particular limitation.

The slurries of the slurry thus prepared are subjected to a drying step (step (iv)) to remove moisture. The drying step is not particularly limited, and it is possible to remove the contaminants from the outside during the drying process and to remove the moisture contained in the slurry or the solid component in a uniformly mixed state.

Next, the crushing step (step (v)) is performed so that the self-bonding force is provided while the moisture contained in the slurry or the solid component is evaporated during the drying process so that the shape of the sericite having a coarse size is made to be in a powder form And the present crushing step is not particularly limited, and it is possible that the crushing step is all possible as long as it is possible to provide a powdery mixture form having a coarse size in which moisture is evaporated.

In addition, in the sintering step (vi), nanometer-sized titanium dioxide, silver metal and silver phosphate are formed on the surface of the sericite, It is aimed at. For this purpose, it is preferable that the titanium source is heated at a relatively low temperature of 450 to 750 ° C for 30 minutes or more in order to maintain the silver metal state, while titanium dioxide (TiO ₂ ) is produced by the present sintering step.

Finally, the cooling step (step (f)) is intended to maintain the functional sericite, which is maintained at a high temperature by the sintering step, at room temperature for convenient transportation and transportation. Titanium and silver phosphate (Ag ₃ PO ₄ ) can be maintained if the coated silver nanomaterials are not oxidized while maintaining their normal state. For this purpose, it is desirable to maintain the state where the inert gas is introduced when the high temperature functional sericite after the sintering step is cooled to room temperature.

Thus, the method for producing a sericite according to the present invention is a method for producing a sericite which is obtained by simultaneously obtaining a silver nano solution and a phosphate by the sol-gel method and coating a silver mixed solution and a titanium dioxide source on the surface of the sericite to thereby exhibit high photoactivity, It is possible to provide a highly functional sericite which has both of these properties.

Hereinafter, embodiments to which the technical idea of the present invention is applied will be described, but it is needless to say that the technical idea of the present invention is not limited to the embodiments.

Example  One

A colloidal silver nano-silver suspension with excellent antibacterial activity and colloidal silver containing silver phosphate excellent in photo-activity in the visible light region were prepared as follows.

4.7464 g of silver nitrate (AgNO ₃ , Kojima Corporation) was precisely weighed in a weighing paper, transferred to a 1-liter beaker, and about 600 ml of distilled water was fed, and silver nitrate was completely dissolved through a Teflon-coated stirrer (Referred to as 'silver nitrate silver solution').

As a reducing agent for preparing a colloidal-phase silver nanosol solution, 0.9513 g of NaBH ₄ was accurately weighed in a 200 ml beaker, and distilled water was supplied to the beaker, which was completely dissolved by stirring (called a 'reducing agent solution').

The silver nitrate (AgNO ₃ ) supplied in the present embodiment is reduced with the reducing agent NaBH ₄ supplied in the same amount or less to prepare a silver metal on the colloid, and the unreduced excess silver nitrate (AgNO ₃ ) In order to provide silver phosphate excellent in optical activity in the light ray region, 2.5 g of sodium phosphate monobasic (NaH ₂ PO ₄ , prenatal) was precisely weighed in a 100 ml beaker, distilled water was supplied, Completely dissolved (referred to as 'phosphate solution').

The silver nitrate solution was slowly added dropwise to the silver nitrate solution while stirring the silver nitrate solution. The silver nitrate was prepared as a colloidal silver metal and the phosphate solution was slowly supplied to the silver antimicrobial agent and the visible light region , A mixed solution containing phosphoric acid having excellent photoactivities was prepared.

The thus prepared mixed solution was transferred to a volumetric flask of 1 L and mixed to prepare colloidal silver having a concentration of 2,700 ppm of silver (Ag) and 1,160 ppm of phosphoric acid on the colloid.

Next, in order to provide a source of titanium dioxide, titanium tetrachloride (TiCl _{4 ,} Sigma Aldrich, 99.9%) was diluted 1/5 with distilled water in an ice bath equipped with a condenser to prepare a solution containing 5 wt% Solution. 100 ml of the titanium tetrachloride solution diluted 1/5 was transferred to a 500 ml beaker, and ammonia water diluted 1/10 with stirring was slowly added dropwise until the pH reached the level of 10, and a white precipitate of Ti (OH) ₄ And the titanium dioxide source of Ti (OH) ₄ with minimized impurities was prepared by filtration and washing five times under reduced pressure.

In order to produce a functionalistic sericite capable of acting as an antimicrobial, hiding power and photocatalyst, 100 g of a 325 meshing sericite of the B & M mining Co., Ltd. were weighed in a 500 mL round flask, 100 ml of colloidal silver and the whole amount of Ti (OH) ₄ were supplied and a uniform composition was maintained while removing moisture using a rotary evaporator. The composition dried in a furnace capable of introducing nitrogen and capable of forming an inert atmosphere was introduced and heated to a temperature of 500 ° C at a heating rate of 5 ° C / min, maintained for 5 hours, cooled to room temperature To produce multifunctional sericite.

As a result of measuring the coating composition on the surface of the sericite thus prepared, titanium dioxide (TiO ₂ ) was 8.3 wt%, nano-sized silver (Ag) was 270 ppm, and silver phosphate was 110 ppm.

Example  2

Multifunctional sericite was prepared by the same procedure as in Example 1, except that the same silver nitrate solution and phosphoric acid silver solution as in Example 1 were used and 0.8456 g of NaBH ₄ was used in the reducing agent solution.

As a result of measuring the coating composition on the surface of the sericite thus prepared, titanium dioxide (TiO ₂ ) was 8.3 wt%, nano-sized silver (Ag) was 240 ppm, and silver phosphate was 230 ppm.

Example  3

Multifunctional sericite was prepared by the same procedure as in Example 1, except that the same silver nitrate solution and phosphoric acid silver solution as in Example 1 were used and 0.7399 g of NaBH ₄ was used as the reducing agent solution.

As a result of measuring the coating composition on the surface of the sericite thus prepared, titanium dioxide (TiO ₂ ) was 8.3 wt%, nano-sized silver (Ag) was 210 ppm, and silver phosphate was 350 ppm.

Example  4

Multifunctional sericite was prepared by the same procedure as in Example 1, except that the same silver nitrate solution and phosphoric acid silver solution as in Example 1 were used and 0.6342 g of NaBH ₄ was used in the reducing agent solution.

As a result of measuring the coating composition on the surface of the sericite thus prepared, titanium dioxide (TiO ₂ ) was 8.3 wt%, nano-sized silver (Ag) was 210 ppm, and silver phosphate was 350 ppm.

Comparative Example  One

325 mesh (Mesh) sericite of B & M Co., Ltd. used in Example 1 was prepared.

Comparative Example  2

A commercially available titanium dioxide (Cosmo Chemical Co., Ltd.) was prepared.

Comparative Example  3: In sericite Phosphate  Uncoated

Multifunctional sericite was prepared in the same manner as in Example 1, except that the phosphoric acid silver solution was not used.

As a result of measurement of the coating composition on the surface of the sericite thus prepared, the concentration of titanium dioxide (TiO ₂ ) was 8.3% by weight and the concentration of nano-sized silver (Ag) was 270 ppm.

Comparative Example  4

In order to compare the workability of the production of multifunctional sericite capable of simultaneously providing titanium dioxide having high activity in the ultraviolet region and phosphorus silver having high photoactivity in the visible ray region and nano-sized silver nanoparticles excellent in antibacterial property, The silver nitrate solution and the reducing agent solution were prepared in the same manner as in Example 1, and the 'reducing agent solution' was slowly dropped while stirring the 'silver nitrate solution' to prepare silver nitrate as a nano-silver suspension on the colloid. In addition, the titanium dioxide source was also prepared as a Ti (OH) ₄ precipitate in the same manner as in Example 1. However, silver phosphate was separately prepared.

The silver nanoparticles solution and the Ti (OH) ₄ precipitate were mixed with sericite and then silver phosphate was added to coat the surface of the sericite. Finally, the coating composition of the sericite surface was 8.3 wt% of titanium dioxide (TiO ₂ ) Silver (Ag) of 270 ppm, and silver phosphate of 110 ppm.

The properties of the antifungal, the hiding power, the photocatalytic efficiency in the ultraviolet ray and visible light range, and the functionality and workability of the sericite or titanium dioxide prepared in Examples 1 to 4 and Comparative Examples 1 to 4 were measured by the following methods.

Experimental Example  1: Measurement of antibacterial activity

The antimicrobial activity was measured by KS F 4403 (test for sterility by sulfur oxidizing bacteria, using strain: Acidithiobacillus thiooxidans ATCC 8085). The measurement results are shown in Table 1 below.

division Antibacterial activity Example 1 Has antibacterial effect Example 2 Has antibacterial effect Example 3 Has antibacterial effect Example 4 Has antibacterial effect Comparative Example 1 No bactericidal effect Comparative Example 2 No bactericidal effect Comparative Example 3 Has antibacterial effect Comparative Example 4 Has antibacterial effect

As shown in Table 1, in the case of the sericite coated with titanium dioxide and the silver nano solution obtained by the sol-gel method as in Examples 1 to 4, there was no sterilization effect in the case of the uncoated sericite as in Comparative Example 1, .

Experimental Example  2: Hiding power (%)  Measure

The hiding power was measured by RHOPOINT Instruments 45 ^o / 0 Opacity / Shade Meter. The measurement results are shown in Table 2 below.

division Hiding power (%) Example 1 86.4 Example 2 86.8 Example 3 86.4 Example 4 86.4 Comparative Example 1 39.7 Comparative Example 2 87.2 Comparative Example 3 86.4 Comparative Example 4 86.2

As can be seen from Table 2, it can be seen that the coating of the silver / phosphoric acid silver on the surface of the sericite has the same effect as that of the titanium dioxide of Comparative Example 2 and the sericite of Examples 1 to 4.

Experimental Example  3: Photocatalyst  efficiency

To confirm the photocatalytic efficiency of the ultraviolet region, 0.01% concentration of methylene blue was dissolved and filled into a 40 × 20 × 15 cm aquarium, and then the sericite prepared in Comparative Example 1 and Examples 1 to 4 was placed on the bottom of the aquarium In order to prevent the inflow of rainwater during rain, it was covered with transparent glass, and then left for one month in the outdoor sunlight. The removal rate of methylene blue dissolved in the water by the photocatalyst was confirmed.

Next, in order to confirm the photocatalytic efficiency in the visible light region, 0.01% concentration of methylene blue was dissolved and filled into an aquarium of 40 x 20 x 15 cm. Then, the sericite prepared in Comparative Example 1 and Examples 1 to 4 was placed in an aquarium The mixture was allowed to stand on the floor for one month in a room where no sunlight was irradiated, and the removal rate of methylene blue dissolved in the water by the photocatalyst was confirmed. The removal efficiency of methylene blue by the photocatalyst was expressed as a percentage of the absorbance of methylene blue photocracked by the photocatalyst based on the absorbance of the methylene blue solution at the concentration of 0.01%.

division UV area (outdoor) Visible light area (indoor) Absorbance Decomposition rate (%) Absorbance Decomposition rate (%) Example 1 1 week 0.804 10.26 0.854 4.69 Two weeks 0.642 28.34 0.746 16.74 Three weeks 0.387 56.81 0.697 22.21 4 weeks 0.124 86.16 0.619 30.91 Example 2 1 week 0.8116 9.42 0.858 4.27 Two weeks 0.648 27.67 0.752 16.07 Three weeks 0.394 56.03 0.692 22.77 4 weeks 0.130 85.49 0.623 30.47 Example 3 1 week 0.808 9.82 0.856 4.46 Two weeks 0.636 29.07 0.755 15.74 Three weeks 0.394 56.03 0.701 21.76 4 weeks 0.136 84.82 0.624 30.36 Example 4 1 week 0.801 10.60 0.848 5.36 Two weeks 0.654 27.01 0.740 17.41 Three weeks 0.379 57.70 0.675 24.66 4 weeks 0.106 88.17 0.624 30.36 Comparative Example 1 1 week 0.874 2.45 0.894 0.22 Two weeks 0.842 6.02 0.880 1.79 Three weeks 0.802 10.49 0.865 3.46 4 weeks 0.764 14.73 0.838 6.47 Billing fee (Control) 0.896 - 0.896 -

As shown in Table 3, in the case of sericite coated with titanium dioxide and silver phosphate (Ag ₃ PO ₄ ) as in Comparative Example 1, the removal rate of methylene blue is insufficient even though ultraviolet rays are irradiated. In particular, in the case of Comparative Example 1, the removal rate of methylene blue is low in the room of the visible light region where no sunlight is irradiated, whereas in Examples 1 to 4 according to the present invention, It was confirmed that the longer the incubation time in the room, the more rapidly decomposed.

Experimental Example  4: Evaluation of workability

The time required for producing the same / similar sericite was measured and the workability was evaluated and shown in Table 4.

division Manufacturing time Example 1 6 hours and 30 minutes Comparative Example 4 11 hours 15 minutes

Referring to Table 4, it was confirmed that the manufacturing time of Example 1 was about 6 hours and 30 minutes, while that of Comparative Example 4 was about 11 hours and 15 minutes.

Accordingly, in the case where a nano-silver suspension and silver phosphate are simultaneously obtained by adding a reducing agent to a silver salt solution according to the present invention to reduce the silver salt solution, and then silver is coated by further adding phosphate thereto, It is expected that the production method of the sericite according to the present invention is excellent in workability and thus can secure a great degree of technology and price competitiveness.

Therefore, the method for producing the sericite according to the present invention can produce a multifunctional sericite having high hiding power and high antimicrobial activity, providing high optical activity not only in ultraviolet rays but also in the visible light region, by a relatively short time and simple manufacturing process The sericite produced in this way is an air sterilizer other than the fields of environmentally friendly organic materials and building interior materials, environmentally friendly livestock materials, functional cosmetics, water treatment environmental materials, environmentally friendly wallpaper, environmentally friendly cement, fiber, cement photocatalyst, soil improvement agent, organic fertilizer, , Air purifiers, and the like.

Claims (13)

(I) Preparing a silver salt solution (a1) obtained by diluting silver salt in distilled water, a titanium salt solution (b1) obtained by diluting an inorganic titanium salt in water or diluting an organic titanium salt in an alcohol solution, respectively;
(Ii) the silver salt solution (a1) is prepared by preparing a colloidal silver mixed solution (A) by a sol-gel method, and the titanium salt solution (b1) is hydrolyzed with an alkali or an acid solution to form a titanium salt precipitate ) Or a colloidal titanium solution (B2); And
(Iii) applying and mixing the sericite to a coating solution obtained by mixing the colloidal silver solution (A) with the titanium salt precipitate (B1) or the colloidal titanium solution (B2) to surface the sericite surface, ,
The colloidal silver solution (A) in the step (ii) is prepared by adding a reducing agent and phosphate to the silver salt solution (a1) prepared in the step (i), and applying a nano-silver suspension using a sol- And silver phosphate,
The titanium salt precipitate (B1) of the step (ii) is prepared by adding dropwise an alkali solution to a titanium salt solution (b1) in which an inorganic titanium salt is diluted in water prepared in step (i), adding titanium hydroxide [Ti OH) ₄ ] precipitate,
The colloidal titanium solution (B2) of the step (ii) is prepared by adding the titanium salt solution (b1) diluted with the organic titanium salt to the alcohol solution prepared in the step (i) Characterized in that it is obtained by supplying water and acid, stirring and aging. The method according to claim 1, wherein, after the step (iii)
(Iv) a drying step of removing water from the surface-treated slurry-form sericite;
(V) a crushing step of crushing the sericite in a dry state;
(Vi) a sintering step of sintering the crushed material; And
(Iii) a cooling step of cooling the sintered lump;
≪ / RTI > further comprising the steps of: The method of claim 1, wherein the silver salt of (ⅰ) step (silver salts) is silver nitrate (AgNO _3), nitrous acid is (AgNO _2), acetic acid (CH ₃ CO ₂ Ag), and the acid is (Ag ₂ CO ₃₎ from And at least one selected from the group consisting of the above-mentioned one or more selected from the group consisting of: The method according to claim 3, wherein the silver carbonate (Ag ₂ CO ₃ ) is insoluble in distilled water, and the solution (i) is prepared by supplying nitric acid (HNO ₃ ) or acetic acid (CH ₃ COOH) Wherein the method comprises the steps of: [2] The method of claim 1, wherein silver is contained in the silver salt solution of step (i) at a concentration of 50 ppm to 0.4% by weight. The method of claim 1, wherein the reducing agent is selected from the group consisting of sodium borohydride (NaBH ₄ ), citric acid, ascorbic acid, tannic acid, and hydrazine hydrate (N ₂ H ₄ H ₂ O) By weight or more. The method of claim 1, wherein the reducing agent is supplied in an amount of 0.55 to 0.99 mol based on 1 mol of silver salts. The method according to claim 1, wherein the phosphate is supplied in an amount of 0.01 to 0.45 mol per mol of silver salts. The method according to claim 1, wherein the inorganic titanium salt is at least one selected from the group consisting of titanium chloride (TiCl ₄ ), titanyl sulfate (TiOSO ₄ ), and titanium sulfate [Ti ₂ (SO ₄ ) ₃ ]
Wherein said organic titanium is titanium tetraisopropoxide (TTIP). ≪ RTI ID = 0.0 > 11. < / RTI > The method for producing a sericite according to claim 1, wherein the alkali solution is at least one selected from ammonia water, sodium hydroxide, and potassium hydroxide. The method of claim 1, wherein the titanium salt solution of step (i) comprises titanium (Ti) at a concentration of 500 ppm to 15 weight%. 3. The method of claim 2, wherein the sintering is performed at a temperature of 450 to 750 占 폚 for 30 to 60 minutes. delete

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