JP2000290114A - Granular antibacterial material and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a granular antibacterial material suitable for the antimicrobial, antifungi and alga prevention treatment of bath water for domestic and business uses, water in tap water and an elevated water tank, pool water, cooling water in a cooling tower or the like and excellent in durability, and also to provide a method for producing the same. SOLUTION: This granular antibacterial material is prepared by supporting glass fine grains comprising 50-80 mol% ZnO, 20-50 mol% B2O5 and/or P2O5 and 0-1 mol% alkali metal oxide with the surface of granular ceramic. This method for producing the granular antibacterial material is to heat a mixture of glass fine grains with granular ceramic to soften the glass fine grains and to make the surface of the granular ceramic support the glass fine grains.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a particulate antibacterial material in which particulate antibacterial glass is supported on particulate ceramic and a method for producing the same, and more particularly, to household or commercial bath water, tap water or elevated water. The present invention relates to a granular antibacterial material used for purifying water of a pool, cooling water of a cooling tower, and the like.

[0002]

2. Description of the Related Art Conventionally, as a method for purifying bath water for home or business use, tap water, water in an elevated water layer, water in a pool, cooling water in a cooling tower, etc., a method using adsorption by activated carbon, ozone and There are a method of sterilizing with ultraviolet rays, a method of sterilizing with a chlorine-based germicide, and the like. Activated carbon has a low disinfection efficiency and is black, which may contaminate water. The method using ozone or ultraviolet rays has a disadvantage that it is limited to a specific application because the equipment cost is high and the running cost such as electric power is high. In the method using a salt-based disinfectant, chlorine is smelled because chlorine remains after the treatment.

[0003] In order to improve these drawbacks, there is a purification method in which water is treated by bringing it into contact with an inorganic antibacterial agent containing a metal having antibacterial properties. However, since most of the inorganic antibacterial agents are fine powders, when added directly to water, turbidity occurs, and it is difficult to remove the inorganic antibacterial agents after the treatment. A method of filling the column with an inorganic antibacterial agent and passing water through the column is also conceivable, but it is not practical due to a large pressure loss and a low water passing speed.

[0004] In order to solve these problems, it is effective to use an inorganic antibacterial agent in the form of granules. in this case,
If the inorganic antibacterial agent itself can be heat-molded, it is possible to use the antibacterial agent itself by molding it into granules,
As an effective method for effectively utilizing the surface area of an inorganic antibacterial agent and obtaining a granular antibacterial material of any size according to the purpose, a method of supporting a particulate antibacterial agent on another carrier has been proposed. .

Japanese Patent Application Laid-Open No. Hei 5-176976 proposes a method in which an inorganic antibacterial agent, which is a fine powder, is supported on the surface of a carrier by melting the surface of a synthetic resin, glass, metal, and various inorganic objects serving as a carrier. ing. This method is a method in which inorganic antibacterial agent particles are supported by colliding with the surface of a carrier that has been melted by heating. However, there is a drawback that antibacterial particles having a stable shape are easily obtained because the carriers are easily bonded to each other. In particular, when the carrier is a synthetic resin, there is a disadvantage that the inorganic antibacterial agent particles easily fall off with time because the durability of the carrier itself is limited.

The present inventors have also filed Japanese Patent Application No. 10-19236.
No. 6 proposes a granular antibacterial material characterized in that an inorganic antibacterial agent having a specific composition is supported on a granular ceramic surface using glassy powder as a binder, but the inorganic antibacterial material supported on the granular ceramic surface is proposed. The amount of the agent differs for each granular ceramic, and there is a problem that it is difficult to obtain a stable quality of a granular antibacterial material.

[0007]

DISCLOSURE OF THE INVENTION The present invention is used in a water treatment method that does not require large-scale facilities and running costs, and is hardly contaminated with water to be treated. It is intended to provide a highly durable granular antibacterial material suitable for antibacterial, antifungal, antialgal, etc., such as tap water, water in an elevated water layer, pool water, cooling water in a cooling tower, and a method for producing the same. .

[0008]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and as a result, have found that fine particles of antibacterial glass having a specific ratio of zinc as an antibacterial metal are supported on the surface of the granular ceramic. The present inventors have found that a granular antibacterial material having excellent antibacterial effect and durability can be manufactured efficiently and stably, and have completed the present invention.
That is, in the present invention, ZnO is 50 to 80 mol%, B ₂ O ₅
And / or P ₂ O ₅ and containing 20 to 50 mol%, the content of alkali metal oxides is a granular antibacterial material comprising fine particles of the glass is supported on particulate ceramic surface 0-1 mol%.

Hereinafter, the present invention will be described in detail. ○ Glass Fine Particles The fine particles of the antibacterial glass in the present invention contain ZnO of 50%.
80 mol% and B ₂ O ₅ and / or P ₂ O ₅ to 20
５０50 mol%, and 0-1 mol% of alkali metal oxide. A preferable content ratio of ZnO is 55 to 75.
Mol%, more preferably 60 to 70 mol%. ZnO is a component necessary for imparting antibacterial performance to glass. However, if it is more than 80 mol%, there is a problem that it is difficult to vitrify stably, and if less than 50 mol%, the antibacterial property of the glass of the present invention is reduced. Will be insufficient.

The preferred content of B ₂ O ₅ and / or P ₂ O ₅ is 25 to 45 mol%, more preferably 3 to 45 mol%.
0 to 40 mol%. When B ₂ O ₅ and / or P ₂ O ₅ is added in an amount of more than 50 mol%, the water solubility of the glass microparticles of the present invention becomes excessive, so that the antibacterial property, discoloration resistance and the antibacterial property of the granular antibacterial material of the present invention are improved. There is a problem that the water resistance is impaired, and if it is less than 20 mol%, there is a problem that it is difficult to obtain a stable glass.

The alkali metal oxide contained in the glass fine particles of the present invention includes alkali metals Na, K and Li.
And two to three of these metal oxides
It is also possible to use seeds in combination. The content ratio of the alkali metal oxide in the glass fine particles of the present invention is 0 to 1 mol%, which is extremely important for exhibiting excellent antibacterial properties, discoloration resistance and water resistance in the granular antibacterial material of the present invention. is important. That is, the content ratio of the alkali metal oxide is 1 mol%.
If it is larger, the water solubility of the glass of the present invention becomes extremely large, and the antibacterial property, discoloration resistance and water resistance of the granular antibacterial material of the present invention are impaired.

The glass-forming component in the antibacterial glass of the present invention is B ₂ O ₅ or P ₂ O ₅ , but other glass-forming components can be added if desired. Preferred examples of other glass-forming components include SiO ₂ , Al ₂ O ₃ ,
TiO ₂ , ZrO _{2 and the} like. The preferable content ratio of other glass-forming components is 20 mol% or less, more preferably 15 mol% or less. Also, if desired
MgO, CaO, CaF _{2 and the} like can be appropriately contained. These so-called “modifying components” are effective in facilitating melting and moldability of the glass, but when contained in a large amount, the water resistance of the glass may be reduced, so that at most 3 mol% or less. And more preferably 1 mol% or less.

In the present invention, the particle size of the glass fine particles is as follows:
It is necessary that the size be such that it easily adheres to the surface of the granular ceramic, and for that purpose, it is preferably 0.1 to 100 μm, more preferably 0.1 to 50 μm.

The method for producing the glass fine particles in the present invention is not limited, and it can be produced within the range of known production techniques. Generally, the raw material mixture of glass is 1000
After melting at ２０００2000 ° C., the melt is quenched to prepare glass, and then the obtained lump glass is pulverized to obtain fine particles of the glass of the present invention. The softening point of the obtained antibacterial glass of the present invention is in the range of 550 to 750 ° C, depending on the composition.

The fine particles of the glass of the present invention exhibit a much higher antibacterial property as compared with the conventional one, and therefore, the ratio of zinc oxide (melting point: about 2000 ° C.) is compared with that of the conventional antibacterial glass. Although many settings are made, zinc oxide itself has the ability to form a glass network, so that it can be melted at an appropriate melting temperature, and by using a quenching means suitable for the cooling characteristics of the melt, the present invention can be used. Can be obtained.

In order to enhance the quenching effect, it is effective to increase the contact area between the molten material and the cooling body. For example, the molten material of glass is sandwiched between two rotating metal rollers cooled by a coolant such as water. Is passed through at a high speed to obtain an extremely large cooling effect. By using this cooling method, vitrification is extremely easy. Further, when cooled by this method, the glass that has come out between the rollers is formed into a thin plate shape, so that it can be easily ground into a powder.

Granular ceramic The granular ceramic referred to in the present invention is a natural or artificially produced inorganic solid material and various glasses such as soda glass, quartz glass, borosilicate glass, and aluminosilicate glass. It is possible. That is, the artificial thing is selected from ceramics, ceramic products, glass, etc., which are commonly known in the world.For example, beads or balls of silica, alumina, zirconia, mullite, glass, etc. can be used, and natural stones can be used. ,
Sand, minerals, or those obtained by processing them can also be used. Further, the granular ceramic is softened at a temperature lower than the softening temperature of the glass fine particles of the present invention (that is, 550 to 750 ° C.).
Ceramics that are stable without causing physical or chemical changes such as melting and decomposition are preferred. The shape is not particularly limited, such as a sphere, a column, a disk, a cube, a rectangular parallelepiped, and an irregular shape.

There is no particular limitation on the particle size of the granular ceramic, but it is selected according to the preferred particle size of the finally obtained particulate antibacterial material. The particle size of the particulate antibacterial material is as described below. The particle size of the glass fine particles carried on the surface of the granular ceramic is very small as compared with the granular ceramic, and the amount of the glass fine particles used is relatively small compared to the granular ceramic as described later. The particle size of the granular antibacterial material is close to the particle size of the granular ceramic that is the raw material. The component, color, specific gravity and the like of the granular ceramic in the present invention are not particularly limited, and the physical properties may be appropriately selected according to the application.

○ Particulate antibacterial material The particle size of the particulate antibacterial material of the present invention is selected depending on its use, but is preferably selected from 0.1 to 5 mm. 0.1m
If it is less than m, the means for separating from the treated water becomes complicated,
Further, when packed in a column or the like, the pressure loss increases. On the other hand, if it exceeds 50 mm, the surface area per unit weight of the granular antibacterial material becomes small, the antibacterial effect is reduced, and the space when packed into a column becomes large and the handling becomes difficult.

The mixing ratio of the fine particles of glass and the granular ceramic can be appropriately changed depending on the intended use, the method of use, the production method and the like, but it is not necessary to use the fine particles of glass that cover the entire surface area of the granular ceramic. The mixing ratio of the glass fine particles is preferably 0.05 to 5% by weight based on the total weight of the glass fine particles and the granular ceramic.

The fine particles of glass used in the present invention are mixed with the granular ceramic, and the mixture is heated to a temperature higher than the softening temperature of the glass, and then cooled and solidified to be adhered and supported on the surface of the granular ceramic. Therefore, a binder for supporting the glass fine particles on the surface of the granular ceramic is not particularly required, but in order to further increase the adhesive force, an organic polymer-based adhesive is used as the binder when mixing the glass fine particles and the granular ceramic. It is also possible to use organic solvents, water, oils and the like. These binders are volatilized and removed when the glass particles are heated to the softening temperature. It is also possible to use silica gel or alumina sol as a binder, but since it remains as silica or alumina even after being heated to a temperature higher than the softening temperature of the glass particles, it is necessary to keep the amount to such an extent that the antibacterial performance is not adversely affected. There is. A typical production method for obtaining a granular antibacterial agent is described below.

(Example of process) First, ZnO is 50 to 80 mol%
And B ₂ O ₅ and / or P ₂ O ₅ containing 20 to 50 mol%, mixing the glass and particulate ceramic particulate content of alkali metal oxides is 0-1 mol%.
By heating the mixture at a temperature equal to or higher than the softening temperature of the glass, the fine particles of the glass are softened and supported on the surface of the granular ceramic. Thereafter, this is cooled to obtain the granular antibacterial material of the present invention.

The granular antibacterial material thus obtained has excellent stability, chemically and physically, in the glass particles carried thereon. It does not deteriorate during use and has a long-term antifungal, antibacterial and anti-algal properties under severe environments.

When using the particulate antibacterial material, its use method or amount may be appropriately selected depending on the application. For example, as for water purification, there is a method of adding an appropriate amount of granular antibacterial material to water to be treated as it is, or passing water through a column packed with granular antibacterial material.

Applications The granular antibacterial material of the present invention is effective as a granular antibacterial material for purifying various types of water requiring sanitary control, and is particularly useful for bath water, tap water and elevated water for home and business use. It is effective in purifying water in the water layer, water in the pool, cooling water in the cooling tower, and the like. In addition, the particulate antibacterial material of the present invention can be used in various fields other than water purification, for example, parks or schools, sandboxes such as kindergartens, stadiums, sports fields,
Particulate antibacterial materials to maintain hygiene in horse racetracks, golf courses, pet sand, earth and sand for agricultural and horticultural use, mortar for exterior use, appreciation aquariums, ikesu, artificial ponds, etc., or grow in the environment in which they are used. It is useful as a granular antibacterial material for suppressing the growth of the obtained bacteria, fungi, algae, etc., and can exhibit a stable antibacterial activity.

[0026]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. << Reference Example 1 >> (Preparation of Glass Fine Particles) A raw material mixture having a composition as shown in Table 1 was prepared in the range of 1000 to 1
After melting at 400 ° C. to produce glass, the obtained glass is wet-pulverized with a ball mill and sieved to have an average particle size of about 10 μm.
(No. 1 to No. 1) were obtained.
4).

<< Example 1 >> (Preparation of granular antibacterial material) The glass fine particles and the granular ceramic obtained in Reference Example 1 were
The mixture was mixed at the mixing ratio shown in Table 2, each mixture was heated to 750 ° C. in a firing furnace to soften the glass fine particles, and then allowed to cool to room temperature, thereby preparing a granular antibacterial material (Samples A to A). Re).

<< Comparative Example 1 >> (The content of the alkali metal oxide in the glass fine particles is other than that of the present invention) 4 was mixed with 99 parts by weight of a porcelain ball (7 mmφ), and the mixture was heated to 700 ° C. in a firing furnace to soften glass fine particles.
By leaving to cool to room temperature, a granular antibacterial material was prepared (Sample No. 2 in Table 2).

Comparative Example 2 Polyester ball (7 mm
φ) and an appropriate amount of toluene were added to a high-speed mixer and rotated. When the ball surface was melted, the fine particles of the glass obtained in Reference Example 1 were no. 1 was added to 99 parts by weight of a polyester ball, and further rotation was continued. Thus, a granular antibacterial material carrying No. 1 was obtained (sample 2 in Table 2).

[0030]

[Table 1]

[0031]

[Table 2]

<< Test Example 1 >> (Evaluation of Antibacterial Property) The antibacterial activity of the granular antibacterial materials produced in Example 1, Comparative Example 1 and Comparative Example 2 was evaluated by the following method. That is, Escherichia coli and Staphylococcus aureus are used as test bacteria, and a granular antibacterial agent is added at a ratio of about 1 g to 75 ml of a bacterial solution adjusted to have about 10 ⁴ cells at 25 ° C. for 1 hour or Shake for 3 hours.
The viable cell count of these test liquids was measured by a pour plate culture method (37 ° C. for 2 days) using a medium for cell count measurement.
Table 3 below shows the results of the antibacterial test obtained as described above.
It was shown to. The initial bacterial count in the antibacterial test, and a porcelain ball (7 mm
The number of bacteria in a control test in which the same operation was performed for (φ) is also shown.

[0033]

[Table 3]

<< Test Example 2 >> (Evaluation of Antibacterial Property after Durability Test) The granular antibacterial material (b) produced in Example 1 and Comparative Example 1
(G) and the granular antibacterial material (L) prepared in Comparative Example 2 (about 10)
0 g was placed in a plastic container, 1 liter of water was added, and the mixture was shaken at 60 ° C. for 24 hours. The same operation was repeated seven times while replacing the water. The granular antibacterial material was taken out, and the antibacterial properties were evaluated in the same manner as above. Table 4 shows the results.

[0035]

[Table 4]

[0036]

According to the present invention, a granular antibacterial material having excellent durability can be obtained. The granular antibacterial material obtained by the present invention can be used for purification of various waters requiring hygiene, particularly for bath water for home use or business use, tap water and water of elevated water layers, water of pools, and cooling towers. It is effective for purifying cooling water and the like. In addition to water purification, various fields where hygiene is required, such as parks or schools, sandboxes such as kindergartens, stadiums, sports fields, racetracks, golf courses, pet sands, agricultural and horticultural soils, exteriors It is also effective in purifying mortar, appreciation aquariums, ikesu, artificial ponds, etc.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) A01N 59/26 A01N 59/26

Claims (3)

[Claims] 1. A glass containing 50 to 80 mol% of ZnO and 20 to 50 mol% of B ₂ O ₅ and / or P ₂ O ₅ and containing 0 to 1 mol% of an alkali metal oxide. A particulate antibacterial material comprising fine particles supported on a granular ceramic surface. 2. The method according to claim 1, wherein the particle size is from 0.1 mm to 50 mm.
The particulate antibacterial material as described. 3. A glass containing 50 to 80 mol% of ZnO and 20 to 50 mol% of B ₂ O ₅ and / or P ₂ O ₅ and having an alkali metal oxide content of 0 to 1 mol%. A method for producing a granular antibacterial material, comprising mixing fine particles and a granular ceramic and heating the resulting mixture to soften the fine particles of the glass and to support the fine particles on the surface of the granular ceramic.