KR100321403B1 - Spherical fine-grained antimicrobial agent having improved uniform dispersibility and preparation method thereof - Google Patents

Abstract

PURPOSE: A spherical fine-grained antimicrobial agent and a preparation method thereof are provided, thereby uniformly dispersing the antimicrobial agent in a product. Therefore, a small amount of the antimicrobial agent in the product can exhibit an improved antimicrobial activity. CONSTITUTION: The spherical fine-grained aluminosilicate crystal particles represented by the general formula of xM2/nO. Al2O3. ySiO2. zH2O are provided, wherein M is alkali metal, n is an atomic value of alkali metal, x and y are the mole number of each component and x is 0.85 to 1.5 and y is 1.75 to 5.0, and z is a content of crystal water and 12 to 22 wt.%; and the spherical fine-grained aluminosilicate crystal particles have an average particle size of 1.0 micrometer or less, specific surface area of 300 to 600 m2/g and cation exchange capacity of 150 to 220 mg CaO/g. The method for preparing the spherical fine-grained antimicrobial agent comprises the steps of: simultaneously or sequentially mixing sodium aluminate and an excessive amount of sodium silicate, maturing the mixture, and followed by crystallization to prepare the spherical fine-grained aluminosilicate crystal particles; and adding one or more than two antimicrobial metals into the spherical fine-grained aluminosilicate crystal particles, wherein the spherical fine-grained antimicrobial agent has a silver content of 0.05 to 10.0 wt.%, and a zinc content of 5 to 25 wt.%.

Description

Spherical fine antimicrobial agent and preparation method thereof

The present invention uses spherical fine particles in the submicron unit as a carrier, which is a fine aluminosilicate crystal grain based on an alkali metal having a high specific surface area and a spherical shape, and an alkali metal ion and an antibacterial metal in the carrier. (Silver, zinc, copper, etc.) relates to a spherical particulate antimicrobial agent substituted with an ion exchange reaction and a method for producing the same.

Conventional inorganic antimicrobials have been prepared by supporting antimicrobial metals on carriers such as zirconium phosphate, calcium phosphate, activated alumina, activated carbon, natural or synthetic zeolites. However, most of them have a yellowing phenomenon or irregular particle shape, so when applied to a product, the dispersibility is poor, and thus, it is difficult to obtain a smooth workability, so that the particles are dispersed in the aggregated state, and thus it is difficult to obtain a uniform antimicrobial activity of the product. In addition, since the inorganic carrier has a particle size of several tens to tens of microns, its application to various applications is limited. Recently, in the case of synthetic zeolites that are widely used as antimicrobial carriers, zeolites for builders (4A-Zeolite) are mainly used as carriers (see Japanese Patent Publication 86-22977, Korean Patent Publication 88-7092). It has poor flow and dispersibility in the shape of a cube with sharp or rounded corners, which requires considerable technical skills to obtain uniform dispersion and uniform antimicrobial activity of the product. Especially in the case of synthetic zeolites (4A-Type), the average particle size is 2 to 3 microns, and the particle distribution range is 1 to 10 microns or more, so it is not directly applied to yarn in the application of textile products requiring antimicrobial activity. There are limitations. The average particle size of the aluminosilicate grains used as the antimicrobial metal carrier in the present invention is submicron (d ₅₀ : 0.75 to 1.0 μm), has a spherical shape, high specific surface area (300 m 2 / g or more), and excellent ions. The antimicrobial activity of the spherical particulate antimicrobial agent having exchange capacity (CaBC: 150 mgCaO / g or more) and using it as a carrier shows an antimicrobial activity of about 99.9% or more in Escherichia coli ATCC 25922 and Staphylo- coccus aureus ATCC 6538) has an antibacterial activity of about 99.8% or more.

The following is a detailed description of the production of spherical particulate antimicrobial agents of the present invention.

The general composition of the alkali metal aluminosilicate crystal grains used in the present invention is as follows.

xM ₂ / _n O. Al ₂ O ₃ . y SiO ₂ . zH ₂ O

Here, M is an alkali metal, sodium (Na), calcium (Ca), potassium (K) and the like, and sodium is most commonly used. n represents the valence of an alkali metal. x and y represent the number of moles of each component and z represents the moisture content. The range of x in the above formula is 0.85 to 1.5, preferably 0.85 to 1.25. If the value of x is too large, the formation of sodalite is accelerated, and if too small, the solubility of the silica component is insufficient, making it difficult to form the basic structure of the aluminosilicate of the desired composition. y is advantageously a molar ratio of SiO ₂ / Al ₂ O ₃ of 1.7 to 5.0 and a low molar ratio of SiO ₂ / Al ₂ O ₃ possible in relation to the ion exchange capacity, preferably 1.80 to 3.0. z is a water content of the aluminosilicate grains, 12 to 22 wt%, preferably 14 to 18 wt%.

In the present invention, a method for producing spherical fine aluminosilicate crystal grains is as follows.

As a raw material of silica, silicic acid, sodium silicate (Na ₂ .SiO _3. Sodium silicate), as a raw material of alumina, sodium aluminate (Na.AlO ₂ , Sodium aluminate), aluminum hydroxide (Al (OH) ₃ , AlOOH) Active alumina and the like are used. As a raw material for replenishing sodium, liquid or solid sodium hydroxide (NaOH) is used. Sodium aluminate and sodium silicate are quantified in the amount required in the above formula, and diluted sufficiently with distilled water. Then, two component solutions are added to the reactor with the baffle simultaneously or one of the two components is put into the reactor first. Slowly add one ingredient and vigorously stir for sufficient mixing of the two components. The mixing of the two components produces an aluminosilicate basic skeleton structure in amorphous state, in which sodium aluminate is added in less than the stoichiometric amount of the two components required in the formula for the production of the desired spherical fine aluminosilicate. Sodium silicate is added in excess, and the addition time is 10 minutes to 1 hour, preferably 15 to 35 minutes. The deficiency of sodium oxide required in the formula may be added when preparing a solution of sodium aluminate or sodium silicate, or diluted in advance using the required dilution water and added to the reactor before mixing. The degree of dilution of the two component solutions is determined in consideration of the ease of mass transfer and crystal growth rate for the formation of the basic skeleton. The running temperature of the above reaction is 25-150 ° C., preferably 55-110 ° C. When the temperature is too low, the rate of dissolution of the silica component for uniform mixing and basic skeleton formation is slow, and the number of amorphous aluminosilicates produced is reduced. When the reaction temperature is too high, the fine amorphous aluminosilicate nuclei are redissolved. As it progresses, it is hard to obtain desired grain size.

The amorphous aluminosilicate base skeleton structure gel (Gel) thus produced is aged for a certain time for stabilization and uniform dispersion. The attribute time is 5 minutes to 1 hour, preferably 10 to 40 minutes. In order to crystallize the finished amorphous aluminosilicate gel, the reaction temperature is gradually raised and the crystallization temperature is 65 to 150 ° C, preferably 75 to 110 ° C. At this time, the dilution solution of the other component with respect to the component added excessively in the mixing reaction is added according to the composition formula. Addition time is 5 to 40 minutes, Preferably it is 10 to 30 minutes.

The crystallization reaction time is 0.5 to 3 hours, preferably 1.5 to 5 hours. After the crystallization reaction is completed, the reaction mixture is filtered to separate the solid and the mother liquor, and the excess alkali and the unreacted substance remaining in the solid are washed with distilled water sufficiently to obtain a solid cake.

Table 1 below is a general physical table measured after drying the spherical particulate aluminosilicate crystal grains prepared by the present invention at 120 ℃ for 24 hours.

Table 1. Table of Physical Properties of Fine Aluminosilicate Grains

Sufficiently suspended spherical fine aluminosilicate crystal grains are suspended by adding water to a solid content of 12 to 15 wt%. Adjust the pH of the suspension with dilute nitric acid to the suspension solution, and then slowly add a solution containing the antibacterial metal to be ion exchanged with sodium ions present in the pores in the aluminosilicate structure.

Types of antibacterial metals are silver, zinc, copper, lead, and the like, and water-soluble salts containing these metals are preferable. A water-soluble salt containing an antibacterial metal was dissolved in water, prepared in a 0.1-5 M solution, and then added. At this time, the reaction temperature is 5 to 95 ° C, preferably 35 to 50 ° C, the reaction time is 0.5 to 5 hours, and preferably 1 to 2 hours. After completion of the reaction, the solids and the reaction mother liquor are separated and filtered, followed by washing with sufficient water to remove the antibacterial metal attached to the carrier surface. In the case of the particulate aluminosilicate crystal grains used in the present invention, like the synthetic zeolite, since the ion exchange reaction with sodium ions present in the pores in the crystal structure, the particle size does not change even after the ion exchange reaction. The antimicrobial metal content of the antimicrobial agent prepared by the present invention is 0.05 to 10.0 wt%, preferably 0.08 to 4.5 wt%, and 5 to 25 wt%, preferably 10 to 20 wt%, of the antimicrobial solids in the case of silver.

3. Embodiment of the present invention

Embodiments of the present invention are as follows.

Example 1.

1802 g of sodium hydroxide solution (Na ₂ O 8.52 wt%) was added to a glass reactor with a baffle, followed by stirring while warming to 80 ° C. 409.6 g of sodium aluminate solution (Al ₂ O ₃ : 24.9 wt%, Na ₂ O: 20.2 wt%) and 461.9 g of sodium silicate solution (SiO ₂ : 28.6 wt%, Na ₂ O: 10.5 wt%) simultaneously The mixture was slowly added. At this time, the mixture was stirred vigorously (600 rpm) for uniform mixing of the two components and homogeneity of the system. The reaction temperature was 90 ° C. and the addition time was 15 minutes and 25 minutes, respectively. After the completion of the addition, the mixture was aged for about 30 minutes, and gradually warmed, and crystallized at 95 ° C. for 5 hours, the solids and the mother liquor were separated, washed sufficiently with water, and the filter cake was dispersed sufficiently by adding water to a solid content of 12wt%. About 15 wt% nitric acid was added to this dispersion to adjust pH to 6.8, and then a solution of about 3.5 M prepared by dissolving a water-containing salt containing zinc in water was gradually added to carry out ion exchange reaction. The reaction temperature was 45 deg. C, and the reaction time was 1 hour. After the ion exchange reaction of zinc, the solids and the filtrate were separated and filtered, and the filter cake was added again to water to disperse in water to a solid content of 12wt%.

To a sufficiently dispersed dispersion, a 0.3 M solution in which a water-soluble salt containing silver was dissolved in water was added to perform a silver ion exchange reaction. The reaction temperature was 45 deg. C and the reaction time was 1 hour. After completion of the reaction, the solids and the filtrate are separated by filtration, and then the excess unreacted matter attached to the surface is sufficiently washed, dried at a hot air temperature of 250 ° C. in a cake dryer, and heat treated at 550 ° C. for 1 hour in an activated furnace to form spherical antimicrobial agents. Was prepared.

Physical properties of the particulate aluminosilicate crystal grains prepared in Example 1 and the microorganisms prepared using the same are shown in Tables 2 and 3, respectively.

Table 2. Physical Properties of Grained Aluminosilicate Grains

Table 3. Properties of Fine Antimicrobial Agents

Example 2.

962.2 g of sodium aluminate solution (Al ₂ O ₃ : 5.3wt%, Na ₂ O: 10.2wt%) was added to the reactor of the same apparatus as in Example 1, followed by stirring. 765.3 g of sodium silicate solution (SiO ₂ : 9.8wt%, Na ₂ O: 5.2wt%) was slowly added to the solution over 20 minutes with vigorous stirring (600 rpm) for uniform mixing. The temperature of 90 ℃ was aged for 40 minutes for uniform mixing and stabilization of the gel. After completion of aging, 192.5 g of sodium aluminate solution (Al ₂ O ₃ : 5.3wt%, Na ₂ O: 14.5wt%) was added slowly over 10 minutes to crystallize. Crystallization time was 4 hours. After crystallization, the process was post-treated in the same manner as in Example 1 to obtain fine aluminosilicate crystal grains. The fine aluminosilicate cake was dispersed by adding water to a solid content of 12 wt% and then in the same manner as in Example 1. After the zinc ion exchange reaction was performed and the zinc ion exchange was completed, the filtrate was separated from the filtrate and the solid content was dispersed again in water so that the solid content is 12wt%, and then slowly added an aqueous solution containing an ammonium nitrate solution and silver. In the same manner as 1, spherical particulate antimicrobial agents containing silver and zinc were prepared. Table 4 and Table 5 show the physical properties of the aluminosilicate crystal grains obtained in Example 2, respectively, and the physical properties of the spherical particulate antimicrobial agent prepared using the same.

Table 4. Physical Properties of Grained Aluminosilicate Grains

Table 5. Properties of Fine Antimicrobial Agents

Table 6 and Table 7 show the results of the antimicrobial activity against E. coli and Staphylococcus aureus against the spherical particulate antimicrobial agents prepared in the present invention, respectively.

Table 6. Antibacterial test results for Escherichia coli ATCC 25922

Table 7. Antibacterial activity test results for Staphlococcus aureus ATCC 6538

Claims (6)

General composition xM ₂ / _n O. Al ₂ O ₃ . ySiO ₂ . zH ₂ O, where M is an alkali metal, n is the valence of the alkali metal, x, y is the number of moles of each component, x is 0.85 to 1.5, y is 1.75 to 5.0, and z is the crystal. Spherical fine aluminosilicate crystal grains of 12 to 22% by weight in water were prepared and used as carriers to substitute antimicrobial metals alone or in combination of two or more, resulting in 0.05 to 10.0% by weight of silver and 5 in zinc. Spherical fine particle antimicrobial agent which is -25 weight%, and its manufacturing method. 2. The spherical fine aluminosilicate and the production method according to claim 1, wherein the value of x is 0.85 to 1.25, the value of y is 1.85 to 3.0 and the value of water content z is 14 to 18% by weight. The particulate alumino according to claim 1, wherein the particles are spherical in shape, have an average particle size of not more than 1,0 µm, a specific surface area of 300-600 m 2 / g, and a cation exchange capacity of 150-220 mg CaO / g. Silicates and methods for their preparation. A spherical fine aluminosilicate and a method for producing the same according to claim 1, characterized in that the sodium aluminate and sodium silicate are mixed at the same time or sequentially mixed, and then crystallized. 5) Sodium silicate is added in an amount of 20 to 40 mol (mol)% of the two components, and mixed and matured. Sodium aluminate is added at the molar ratio required in the composition formula before crystallization. Spherical fine aluminosilicate and production method thereof. The antimicrobial agent according to claim 1, wherein the antimicrobial metal is substituted alone or in combination of two or more thereof, wherein the silver content is 0.08 to 4.5% by weight and the zinc content is 10 to 20% by weight.