JPS6328402B2 - - Google Patents

Description

[Detailed description of the invention]

BACKGROUND OF THE INVENTION A. Technical Field to which the Invention Pertains More specifically, the present invention relates to an antibacterial composition and a method for producing the same. The present invention relates to a novel antibacterial composition that is excellent in antibacterial properties and retains antibacterial activity, and a method for producing the same. B. Description of Prior Art It is known that metal ions, zinc ions, copper ions, silver ions, etc. have antibacterial activity. for example,
Silver ions are generally widely used in the form of silver nitrate aqueous solutions as disinfectants and sterilizers, but when used in the form of a solution, it is inconvenient to handle, and its uses are naturally limited. On the other hand, it has also been proposed that silver or the like be retained in activated carbon, alumina, or silica gel-based adsorbent materials, and then placed in a container or packed into a tower of an appropriate shape for use in sterilizing liquids. However, the latter case has drawbacks in terms of the retention capacity of the antimicrobial metal for the adsorbed substances and its leakage into the liquid phase. For example, when activated carbon is brought into contact with an aqueous solution of silver nitrate to retain silver in the activated carbon phase, increasing the concentration of silver nitrate in the aqueous solution phase will increase the amount of silver adsorbed to the activated carbon phase. Obviously, there is a limit to the amount of silver adsorbed. Additionally, as the amount of silver retained in the activated carbon phase increases, the tendency for solid phase silver to leak out prematurely or to leak out in an excessive amount increases when a solution is brought into contact with such silver-containing activated carbon. However, there is a phenomenon in which the amount of silver eluted into the sterilizing solution ultimately exceeds the permissible amount. In order to prevent such silver elution phenomenon as much as possible, for example, silver-containing activated carbon intended for sterilization with a suppressed silver content to about several hundred ppm is commercially available. However, from the viewpoint of long-term use, the bactericidal effect of such bactericides is not necessarily satisfactory. Regarding silver regulations, the Public Health Service of the United States sets it at below ppb, West Germany sets it at below 100 ppb, and Switzerland sets it at below 200 ppb. Judging from such regulated plants, when using silver-containing bactericidal agents, it is urgent to minimize the leakage of silver into the solution and maximize the bactericidal effect over a long period of time. Summary of the Invention As a result of extensive research aimed at improving commercially available disinfectants, the present inventor has discovered that an antibacterial composition containing a composite of antibacterial metals, carbonates, and zeolites has high mechanical strength and water resistance. The present invention was achieved based on the discovery that it has excellent antibacterial properties and has many advantages over known bactericidal agents in terms of antibacterial activity and long-lasting effect. It is therefore a principal object of the present invention to provide an antimicrobial composition consisting essentially of an antimicrobial metal-carbonate-zeolite. Another object of the present invention is to provide an antimicrobial composition consisting essentially of an antimicrobial metal-carbonate-zeolite-binder. Another object of the present invention is to sinter a composite material consisting essentially of an antibacterial metal-carbonate-zeolite-binder, which has excellent mechanical strength, water resistance, heat resistance, and ability to retain antibacterial properties. An object of the present invention is to provide a body-like antibacterial composition and a method for producing the same. Other objects and advantages of the present invention will become apparent in the following. DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the formation of a mixture of an alkaline earth metal carbonate and a zeolite on which antibacterial metal ions selected from silver ions, zinc ions, copper ions or mixtures thereof are adsorbed by ion exchange. The present invention relates to an antibacterial composition suitable for water treatment consisting of substances. The present invention also provides a composite of a zeolite and a binder on which antibacterial metal ions selected from silver ions, zinc ions, copper ions or mixtures thereof are adsorbed with alkaline earth metal carbonate and a composite of zeolite and a binder. Alternatively, wet mixing is carried out in the presence of an aqueous urea solution, the resulting mixture is molded into a desired shape, and then dried, and finally the temperature is within a temperature range other than the start of thermal decomposition of carbonates and the heat of zeolite is The present invention also relates to a method for producing an antibacterial composition suitable for water treatment, which comprises baking at a temperature below the onset of decomposition. The term "antibacterial metal" used in the present invention refers to a metal used as a bactericidal agent in a broad sense, but if it is to be limited, it may be one selected from the group consisting of zinc, copper, and silver, or a metal selected from the group consisting of zinc, copper, and silver. Defined as a mixed metal. The antibacterial composition of the present invention is essentially composed of three components: carbonates, zeolites, and antibacterial metals, but in actual use, a binder is added as a subcomponent to strengthen the binding force between particles. It is added and molded into a fired body. Since the fired body formed into a desired shape by firing the composition of the present invention is used in contact with a liquid for sterilization purposes, it is required that the fired body has excellent water resistance and strength. The carbonate used as one of the main components of the antibacterial composition of the present invention is preferably insoluble or sparingly soluble in water. In particular, carbonates of alkaline earth metals (carbonates of magnesium, calcium, strontium, and barium) are sparingly soluble in water, and their thermal decomposition temperatures are high, so the final calcination of the antibacterial composition requires considerable high temperatures. This has the advantage of being able to be fired in a sintered body with excellent hardness. The carbonate used as a component of the antibacterial composition of the present invention may be one or more of the above-mentioned alkaline earth metal carbonates. Further, there is of course no problem even if some basic salt etc. are mixed into the carbonate material. Calcium carbonate is an example of an alkaline earth metal carbonate suitable for use in the present invention. It is sparingly soluble in water, with a solubility in water of about 15 to 20 ppm at room temperature, and its thermal decomposition temperature is high, around 825°C, so good results can be obtained when used as the carbonate component of the present invention. .
In the present invention, one or more of the above-mentioned alkaline earth metal carbonates are used in the form of particles or powders, which are added, wet-molded, dried,
This has the effect of maintaining extremely high strength of the antibacterial composition of the present invention obtained by firing. Alkali metal carbonates (lithium, sodium, potassium, etc.) are soluble in water, and when used as a component of the carbonate constituting the antibacterial composition of the present invention, the composition of the present invention is used to dissolve the alkali metal carbonate. When carrying out sterilization, a considerable amount of carbonate may be eluted into the liquid, which is undesirable. As is well known, the zeolite used as a component of the antibacterial composition of the present invention is an aluminosilicate having a three-dimensional skeleton structure, and has the general formula xM
It is expressed as 2/nO.Al ₂ O ₃ .ysio ₂ .ZH ₂ O. However, M represents a metal capable of ion exchange, and is usually a monovalent to divalent metal. n represents the valence of the metal, x and y represent the coefficients of metal oxide and silica, respectively, and Z represents crystal water. The zeolite used as a component of the antibacterial composition of the present invention may be either a synthetic product or a natural product, but a thermally stable zeolite is more preferred. Suitable synthetic zeolites include A-type zeolite, X-type zeolite, Y-type zeolite, mordenite, and the like. Furthermore, high-silica synthetic zeolites such as ZSM can also be used. On the other hand, natural zeolites include clinoptilolite, mordenite,
Chabazite, Erionite, Phillipsite, Analcime, Faujasite, and the like are suitable as zeolites for use in the present invention. These natural and synthetic zeolites are porous with well-developed pores and therefore have a large specific surface area, and are usually used in the form of particles or powder as one of the components of the antibacterial composition of the present invention. Ru. Next, the composition of the antibacterial composition of the present invention will be described. As mentioned above, the antibacterial composition of the present invention is mainly composed of carbonate, zeolite, and antibacterial metal, but in actual use, organic and/or inorganic binders may be added to this to increase the firing strength. It is added and molded into the desired shape by wet molding. It goes without saying that the antibacterial composition of the present invention may contain inorganic adsorbent substances such as silica gel and alumina as subcomponents in addition to the above-mentioned main components. As mentioned above, the antibacterial composition of the present invention is actually used as one or two carbonates of alkaline earth metals.
It is mainly composed of a fired body obtained by blending a binder with a composition consisting of at least one natural or synthetic zeolite and an antibacterial metal and firing the mixture. Here, using silver, zinc, and copper as examples of typical antibacterial metals, their content in the fired body and the weight ratio of carbonate to zeolite will be described. When the antibacterial metal is silver, the silver content in the fired body is
It is preferably within the range of 0.001 to 20%, and the weight ratio of carbonate (C) to zeolite (Z) C/Z = 0.03
It is preferable that it is within the range of ~4. Bacteria, such as streptococcus
(Stapylococcus aureus), Escherichia Coli, Pseudomonas aeruginosa, etc.
Also fungi, such as mold (Aspergillus flavus)
In order for the antibacterial composition of the present invention to have a sufficient bactericidal effect, the silver content in the composition of the present invention is desirably in the range of 0.001 to 20%, as described above. and the preferred range is 0.005~
It is 15%. When the antibacterial metal is zinc, the zinc content in the fired body is at least 0.04%, and the weight ratio C/Z of carbonate (C) and zeolite (Z) is within the range of 0.03 to 3. It is preferable. On the other hand, when only copper is used as the antibacterial metal, it is preferable that the copper content in the fired body is at least 0.03% or more and the above C/Z is within the range of 0.03 to 3. Next, the reason for limiting the numerical values as described above will be explained. In the present invention, various blending ratios of calcium carbonate, natural zeolite or synthetic zeolite, and binder were varied, and the content of silver, zinc, or copper was also varied to produce fired bodies of various antibacterial compositions. evaluation and measurement of the mortality rate against fungi. When evaluating antibacterial properties
Staphylococcus aureus, Escherichia Coli,
Evaluation was performed by the disk method using bacteria such as Pseudomonas aeruginosa. On the other hand, Aspergillus flavus was used to measure the mortality rate against fungi.
The mortality rate against Aspergillus flavus is 100% when the fired body containing zinc-A-type zeolite-calcium carbonate-binder of the present invention contains 16.2% zinc.
It was hot. In addition, the fired body is a composite of zinc-Y-type zeolite-calcium carbonate-binder, which has a zinc content of 9.3%.
%, the mortality rate against Aspergillus flavus is
98%, while Staphylococcus aureus and
It was also found to have good antibacterial activity against Escherichia Coli bacteria. Zinc is present in the fired body of the former.
When the zinc content was 1.8% and 0.11%, the mortality rate against Aspergillus flavus was 82% and 37%, respectively, and when the zinc content was 0.04%, the mortality rate against the above fungi was 82% and 37%, respectively.
It dropped to 26%. When the zinc content was 0.04% or less, the antibacterial activity further decreased, and when the zinc content was around 0.02 to 0.03%, the mortality rate was 10% or less in all tests. Based on the above reasons, the amount of zinc in the fired body of the present invention was limited to 0.04% (anhydrous basis) or less. Tests similar to those for the above-mentioned zinc-containing fired body were conducted for the copper-containing main fired body, and a copper content of 0.03% (anhydrous standard) was set as the lower limit showing a preferable antibacterial effect. The reason for this is based on the following. In the fired body of the present invention having a copper content of 5% or more,
The mortality rate against Aspergillus flavus was 95 to 100% in both tests of fired bodies using two types of zeolite materials, natural and synthetic. On the other hand, in a calcined body with a copper content of 2 to 2.5%, the mortality rate against the above bacteria was 70% in both tests using two types of zeolite, natural and synthetic zeolites.
The mortality rate was ~88%, and when the copper content was around 1%, the mortality rate was 60-67%. On the other hand, in the calcined body of the present invention with a copper content of 1%, Escherichia Coli, Pseudomonas spp.
The antibacterial effect was still confirmed against Aerginosa bacteria. In a fired body with a copper content of 0.03% or less, the effect against the above-mentioned bacteria decreases significantly as the copper content decreases. Therefore, in the fired body of the present invention containing only copper as an antibacterial metal, 0.03% (anhydrous standard) was set as the lower limit. A similar test was conducted on silver-containing fired bodies, and it was found that in compositions where the silver content was below the lower limit of 0.001%, the antibacterial effect significantly decreased as the silver content decreased, whereas when using silver with a silver content above the upper limit, However, it was discovered that the bactericidal effect was independent of the silver content and remained almost constant, so the ranges for each metal were set as described above. Next, the quantitative relationship between carbonate and zeolite in the composition of the present invention will be described. C/Z=0.03～
A range of 4 is preferred. When C/Z is 0.03 or less, the mechanical strength of the molded article of the antibacterial composition of the present invention has a drawback that it decreases significantly as the calcium carbonate content decreases. Generally, the strength of the compositions of the present invention increases in proportion to the amount of binder used and the content of calcium carbonate. On the other hand, in the range where C/Z is 4 or more, there is a drawback that as the amount of calcium carbonate added increases, it becomes gradually impossible to perform wet molding satisfactorily. In the region of C/Z≦4, the silver and zinc of the present invention are very excellent in terms of mechanical strength and water resistance, and are satisfactory in terms of antibacterial effect and retention ability, as can be seen from the examples described below. It is possible to produce antimicrobial compositions containing single or mixed metals such as copper. Next, the characteristics of the method for molding the antibacterial composition of the present invention will be described. The antibacterial composition of the present invention is molded by a wet molding method. That is, it can be obtained by wet mixing a carbonate-antibacterial metal-zeolite complex in the presence of water or an aqueous urea solution using only an inorganic binder or a combination of organic and inorganic binders. The mixture is molded into an appropriate shape using a molding machine, and then dried at a temperature below the onset of thermal decomposition of the carbonate component to be used and below the onset of thermal decomposition of the zeolite component to be used. It is put into actual use by firing. The carbonates and zeolites used as components of the antibacterial composition of the present invention have already been described in detail and will therefore be omitted here. The antibacterial metal used in the present invention is either added in the form of water-soluble salts such as nitrates or sulfates, or stabilized by holding a single antibacterial metal or a mixture of both in zeolite in advance. It is added in the same state. In particular, according to the latter method, it is possible to prepare an active antibacterial composition in which the antibacterial metal is stably retained in the zeolite skeleton and the antibacterial effect is sustained over a long period of time. In the latter case, an aqueous solution of a water-soluble zinc salt, copper salt, silver salt, or a mixed salt of the above, such as silver nitrate, copper nitrate, zinc nitrate, or a mixed salt of the above, and powder to particulate natural or synthetic zeolite are mixed at room temperature. or high temperature (e.g. 60° to 90°C)
If ion exchange is carried out in an acidic region with a pH of 7 or lower, a part or most of the ion exchange groups in the zeolite skeleton will be converted to silver, zinc, copper, or the above-mentioned mixed metal types. It is also possible to carry out ion exchange into A-, By adjusting the concentration, reaction temperature, and time of the salt solution brought into contact with the zeolite during ion exchange, the amounts of silver and zinc retained in the zeolite phase can be changed as desired. By carrying out such ion exchange, the antibacterial metal is retained extremely uniformly throughout the porous zeolite, so the above-mentioned ion exchange method is preferred as a method for retaining the antibacterial metal. In addition, the antibacterial metal in the zeolite solid phase, which has a large internal specific surface area, is very stably bound to the zeolite matrix and immobilized in an active state. When the antibacterial composition in such a state comes into contact with water, it not only has a large antibacterial effect, but also has minimal elution of antibacterial metal ions into the aqueous solution phase compared to known disinfectants. This has the advantage that the concentrations of silver, copper and zinc are all below the regulatory values. As mentioned above, the antibacterial composition of the present invention comprising carbonate, antibacterial metal, and zeolite is wet-molded together with an inorganic binder or an organic-inorganic binder to form beads, tablets, pellets, or cylinders. It is formed into a shape, plate shape, honeycomb shape, or other suitable shape. A suitable moisture content during wet mixing is 18 to 45%, and by maintaining the moisture content in this range and mixing for 3 to 5 hours, a blend that is easy to mold can be obtained. However, the moisture required for incorporation can be provided simply by adding water to the above composition or by adding an aqueous urea solution. By adding an aqueous urea solution, urea decomposes into gases such as NH ₃ , CO ₂ , and H ₂ O during calcination of the antibacterial composition, and the antibacterial composition becomes more porous due to the foaming phenomenon caused by the above gases. There are advantages to becoming Next, the binder used in molding the antibacterial composition of the present invention will be described. Preferred examples of the inorganic binder include bentonite, diatomaceous earth, kaolin, colloidal silica, and colloidal alumina. On the other hand, organic binders include celluloses (crystalline cellulose compounds such as methylcellulose, carboxymethylcellulose, and hydroxyethylcellulose), molasses,
Preferred examples include alginates and the like.
These inorganic and organic binders may be used alone or in combination, but when molding the antibacterial composition of the present invention, in particular, inorganic binders alone or in combination and organic-inorganic bonds may be used. It is preferable to use a combination of agents. Now, the amount of the above-mentioned binder used is controlled by the physical properties of the carbonate and zeolite that are the constituent components of the antibacterial composition, as well as the ratio of these amounts used, but in normal cases, it is based on the total amount of the above materials. A suitable range is 7-38%. When using organic and inorganic binders together, the total amount of both should be in the range of 7 to 38%, and the former should be in the range of 2 to 3%.
is an appropriate amount. Next, the fired body made of carbonate, zeolite, antibacterial metal, and binder is molded into a predetermined shape through a mixing process, and then dried at around 100°C.
It is adjusted to exhibit a constant shape distribution. The dried molded body that has undergone this adjustment process is fired in a temperature range below the onset of thermal decomposition of the carbonate and zeolite used as components, to finally obtain a fired body that can be used in actual use. The firing temperature range in this case is related to the types of components used, but in general, 350° to 650°C is appropriate, and 400° to 600°C is the most preferred temperature range. The antibacterial composition of the present invention prepared by the above-mentioned method is structurally extremely stable, and the presence of antibacterial metal oxides is hardly seen in X-ray diffraction, indicating that the antibacterial property in the composite is very stable. Most of the metals are bound to and stably held in zeolite. Since such an antibacterial composition is in an activated state, it is characterized by high antibacterial activity. Furthermore, the antibacterial composition of the present invention obtained by the above-mentioned method clearly has significantly greater mechanical strength and density than the examples described below, and also has an excellent advantage in terms of antibacterial retention ability. . Furthermore, it has been confirmed that when such a fired body comes into contact with a liquid, the antibacterial metal in the antibacterial composition is easily ionized, so that sterilization can be carried out under favorable conditions. It was also confirmed that during the antibacterial test, the elution of antibacterial metals into the liquid phase was extremely small. Next, embodiments of the present invention will be described with reference to Examples, but the present invention is not limited to these Examples unless the gist thereof is exceeded. Example 1 This example relates to the preparation of silver zeolite, which is a constituent of the antibacterial composition of the present invention. Approximately 2 kg of A-type zeolite fine powder (commercially available NaZ-type) with a specific surface area of 549 m ² /g and an average particle size of 3 μm was collected, and approximately 4 kg of a 0.1 M silver nitrate aqueous solution and water were added to bring the total volume to 7.1 kg. held. The slurry mixture in this state was kept at room temperature under stirring for 7 hours. A part of the sodium in the ion exchange group of the zeolite was converted into silver by the above ion exchange reaction to form NaAgZ type. Next, the NaAgZ solid obtained by filtration was washed with water until excess silver ions were removed, and then the NaAgZ
It was dried at 110°C. In this conversion test, NaAgZ
Approximately 2008 g of dry powder was obtained. In this case, dry
The silver content in the NaAgZ powder was 2.07%. Example 2 This example relates to a method for preparing the antibacterial composition of the present invention. For 350 g of silver-zeolite (NaAgZ-dry powder) obtained in Example 1
150-200 mesh of calcium carbonate fine powder
Added 350g. To the above mixture, 30% (210 g) of 100-200 mesh fine bentonite powder was added as an inorganic binder, and the mixture was mixed using a mixer for about 4 hours. Next, 26% water was added to the mixture and wet mixing was carried out for about 3 hours. The mixture obtained by this process was molded using a twin-screw molding machine to obtain 1/16" pellets. Subsequently, the pellets were dried at 100° to 110°C, and the length of the pellets was determined. The dry pellets were adjusted to 530° to 550° using a flasher.
℃ for 3 hours and 30 minutes to obtain a 1/16" fired body of the antibacterial composition of the present invention [Ag content = 0.89% (anhydrous basis)]. Hardness first
Shown in the table. In addition, the average value of the apparent density of this product is
It has reached 1.639.

[Table] The values shown are the results of a sampling inspection of the antibacterial composition obtained in this example, and the average hardness of 1/16" pretz (fired) =
It has reached 12.3Kg/pellet. Even when looking at the average values of apparent density and hardness, it is clear that the antibacterial composition of the present invention has extremely high hardness and high durability, which indicates that it is suitable for sterilization purposes (Example (See 5). Example 3 This example describes the use of natural zeolite materials to prepare antimicrobial compositions of the present invention. 2.5 kg of natural mordenite zeolite powder (100 to 200 mesh) having a specific surface area of 348 m ² /g was ion-exchanged using a silver nitrate solution at room temperature in the same manner as described in Example 1 to obtain a powder containing mordenite. Silver-substituted natural mordenite was obtained by converting some of the metals in the exchange groups to silver. Next, 2.3 kg of the above-mentioned dry powder of silver-type mordenite was collected, and 28.3% (650 g) of 150 to 200 mesh powdered calcium carbonate was added thereto. Furthermore, 15.2% (448g) of 100-200 mesh fine bentonite powder was added to the above mixture as an inorganic binder.
and 2% (59 g) of methyl cellulose (commercial product from Tokyo Kasei Kogyo Co., Ltd.: 7,000 to 10,000 cps (viscosity of a 2% aqueous solution at 20°C)) as an organic binder and mixed with a mixer. I did this for two hours. Next, a 3% aqueous urea solution was added to the mixed powder, and wet mixing was carried out for 3 hours and 10 minutes. In this case, the moisture content at the end of mixing was 27%. The mixture obtained in the above process was molded using a twin-screw molding machine to obtain 1/16" pellets.Subsequently, the pellets were dried at 100° to 110°C, and then the length of the pellets was Adjustment was carried out using a flasher.Finally, the 1/16" dried pellets were heated to 550° to 560°C for 3
The antibacterial composition of the present invention is baked for a time of 1/16
A fired body [Ag content = 1.52% (anhydrous basis)] was obtained.

[Table] The hardness of the antibacterial composition obtained in this example is shown in Table 2, and the values shown are the results of a sampling test. The average hardness of the fired 1/16″ pellets reached 13.4Kg/pellet.
From this, it is clear that the antibacterial composition of the present invention has excellent hardness. Example 4 This example relates to the evaluation of the antibacterial activity of the antibacterial composition of the present invention obtained in Example 2 and the fungal mortality rate relative to the antibacterial compositions obtained in Examples 2 and 3. When evaluating antibacterial activity, test substance is 100mg/ml.
It was turbid to a concentration of 100% and soaked into the disk. Mueller Hinton medium was used for bacteria, and Sabouraud agar medium was used for fungi. The test bacteria were dispersed in a medium suspended in physiological saline at 10 ⁸ /ml using a 0.1ml Conlage stick. The test disk was attached onto it. For judgment, the presence or absence of inhibition zone formation was observed after holding at 37°C for 18 hours. On the other hand, for fungi, 30℃
Judgment was made after holding for 7 days. The fungal mortality rate was measured by the following method.
1 of Aspergillus flavus spore suspension (10 ⁴ /ml)
ml was poured into 9 ml of a suspension of the test substance (500 mg/ml) and allowed to react at 30°C for 24 hours. of this
Disperse 0.1ml onto Sabouraud agar medium and incubate at 30°C for 48 hours.
After holding for a period of time, the number of surviving specimens was measured and the mortality rate was calculated.

[Table] Table 3 shows the antibacterial composition of the present invention obtained in Example 2 [1/16″ pellets (calcined); Ag=0.89
% (anhydrous standard)] was used as a fine powder to evaluate its antibacterial properties. As shown, it was found that good results were obtained for all four types of bacteria. As a comparative example, the zeolite material of Example 1 (A-type zeolite
The results of the antibacterial evaluation of Na-type dry powder)
As noted in the table, zeolite alone has no antibacterial effect. Table 4 also shows the antibacterial composition of the present invention obtained in Example 2 [1/16'' pellets (calcined); Ag=
0.89% (anhydrous basis)] and its powder and the antibacterial composition of Example 3 [1/16″ pellets (calcined):
Ag = 1.52% (anhydrous standard)] was measured using Aspergillus flavus as the fungus. As is clear from the table, there is no doubt that the antibacterial composition of the present invention exhibits extremely high antibacterial effects against fungi. On the other hand, as noted in the comparative example in the same table, synthetic or natural zeolite materials alone have no effect on fungi. However, the evaluation test for antibacterial activity and the measurement of the mortality rate of the pulverized products listed in Table 4 are the same as those described above. In addition, the mortality rate of the molded body described above was measured by immersing the antibacterial molded body in a suspension of Aspergillus flavus spores ( ¹⁰⁴ spores/ml) according to the method for measuring the mortality rate described above. .

[Table] Example 5 This example relates to testing the water resistance and ability to retain antibacterial activity of the antibacterial composition of the present invention. Approximately 15 g of the antibacterial composition of the present invention (calcined 1/16" pellets) obtained in Example 2 was collected into a small glass column with an inner diameter of 22 mm, and was washed back with water to uniformly fill the column. To this, city tap water (Ca ²⁺ = 17ppm; Mg ²⁺ = 6.8ppm; Cl = 34ppm) was added at 33±
A test was conducted on the water resistance and antibacterial ability of the composition of the present invention by passing water through it at a flow rate of 1.5 ml/min. Table 5 shows the relationship between the amount of water passing through and the silver concentration in the effluent from the small column. During the test, when the liquid volume reached the indicated value, a small amount of the liquid flowing out from the bottom of the column was sampled, and the concentration of silver in the liquid was determined by atomic absorption spectrometry. As can be seen from Table 5, the elution of silver from the antibacterial composition of the present invention was extremely small, in ppb-amount, and a satisfactory result was obtained. During the water flow test, no damage to the shape of the molded product of this composition was observed, and it was therefore found that the molded product had excellent water resistance. Next, the total effluent volume mentioned above is

[Table] In order to confirm the sustainability of the antibacterial activity of the used antibacterial composition that had completed the 201 water flow test, the fungal mortality rate was measured using Aspergillus flavus. Since the method for this measurement was the same as that for measuring the fungal mortality rate shown in Example 4, only the results are shown in Table 6. It is clear from this table that the antibacterial effect of the composition of the present invention is large and that the antibacterial properties are maintained for a long time.

[Table] Example 6 This example relates to a method for preparing copper-A-type zeolite (NaCuZ), which is used as one of the components of the antibacterial composition of the present invention, in which zeolite is preliminarily loaded with copper. Dry powder of A-type zeolite (specific surface area 673m ² /g; chemical composition, 1.01Na ₂ O.
Al ₂ O ₃・1.96SiO ₂・XH ₂ O) 0.2M for approximately 1.6Kg
Add 4.8 g of cupric sulfate solution and water to bring the total volume to approx.
It was held at 5.7. In this case, the pH of the mixture was adjusted to 4.6 using a dilute acid or alkaline solution. The mixture was stirred at room temperature for 8 hours. After completion of the above ion exchange reaction, centrifugation was performed to separate the solid phase. Next, the zeolite solid phase was washed with water until no sulfate ions were observed.
The obtained NaCuZ was dried at 100° to 105°C. In this example, 1.55 kg of NaCuZ dry powder was obtained. Example 6 Preparation of NaCuZ Yield: 1.55 Kg (dry powder) Solid phase metal component of NaCuZ: ₂ ⁺ = ^0.2237 ; Copper made by pre-holding copper in zeolite used as one component.
This paper relates to the preparation of A-type zeolite (NaCuZ). 5.3 kg of 0.3M cupric sulfate solution was added to 1.6 kg of the same A-type zeolite powder used in Example 6.
and water were added to maintain the total volume at approximately 5.9 g.
In this case, the Hz of the mixture was adjusted to 4.5. After the mixed solution was humidified and kept at about 65° C., it was continuously stirred at the same temperature for 4 hours. After the above ion exchange reaction was completed, centrifugation was performed to separate the solid phase. Next, the zeolite solid phase was washed with water until no sulfate ions were observed, and the resulting NaCuZ
was dried at 100° to 105°C. In this example, NaCuZ
1.57Kg of dry powder was obtained. Example 7 Preparation of NaCuZ Yield: 1.57 Kg (dry powder) Solid phase metal component of NaCuZ: ₂ ⁺ = ^0.3779 ; This invention relates to the preparation of zinc-A-type zeolite (NaZnZ), which is used as a component of the zeolite and contains zinc in advance. Dry powder of A-type zeolite (specific surface area 692cm ² /g; chemical composition, 1.02Na ₂ O.
Al ₂ O ₃・1.94SiO ₂・XH ₂ O) 0.8M for approximately 1.3Kg
Add subsalt chloride solution, 3.3 liters and water to bring the total volume to approx.
It was held at 4.6. In this case, the pH of the mixture was adjusted to 4.2. After raising the temperature of the mixed solution and keeping it at 50°C, continuous stirring was performed at the same temperature for 6 hours. After the above ion exchange was completed, centrifugation was performed to separate the solid phase. Next, the zeolite solid phase was washed with water until no chloride ions were observed, and the obtained NaZnZ was dried at 100° to 105°C. In this example, 1.22 kg of dry powder of NaZnZ was obtained. Example 8 Preparation of NaZnZ Yield: 1.22Kg (dry powder) Solid phase metal component of NaZnZ: ²⁺ = 0.5914; ⁺ =
0.4086 (equivalent fraction) Example 9 This example relates to a method for preparing a zinc-clinoptilolite type in which natural zeolite is preliminarily loaded with zinc to be used as a component of the antibacterial composition of the present invention. . 1M zinc chloride solution for approximately 600g of fine powder of natural clinoptilolite (produced in North America)
Added 1.2. In this case, the pH of the mixture obtained is 4.1
It was adjusted to The mixture containing the above zeolite was stirred at room temperature for 6 hours. After the completion of the above ion exchange reaction, centrifugation was performed to separate the solid phase, which was washed with water until no chlorine ions were observed, and then dried at 100° to 105°C. 580 g of petilolite dry powder was obtained. Example 9 Preparation of zinc-clinoptilolite Yield: 580 g (dry powder) Zinc content: Zn = 1.74% (anhydrous basis) Next, the antibacterial composition of the present invention was prepared under the conditions illustrated in Table 7. Molded. In Examples 10 and 11, NaCuZ and calcium carbonate powders were molded using bentonite and a combination of bentonite and methylcellulose binder, respectively. In the latter case, methylcellulose is used as an organic binder (viscosity of 2% aqueous solution at 20°C = 7000~
10000cps) 2% addition is being carried out. Example 12
In Example 13, wet molding was carried out by adding only a bentonite binder to a mixed powder of NaZnZ and calcium carbonate, and in Example 13, a mixture obtained by adding calcium carbonate powder to zinc-clinoptilolite (natural zeolite) was carried out. In contrast, as in Example 12,
Molding was carried out by adding only a bentonite binder. The moisture required in the above wet mixing was achieved by simply adding water as indicated or by adding a 3% aqueous urea solution to maintain the moisture content as indicated. Next, drying of the molded pellets was carried out at 100° to 105°C in all examples, while calcination of the dried pellets was carried out at 510° to 520°C in Examples 10-12.
℃ temperature range for 4.5 hours, and in Example 13 530℃ ~
The test was carried out in a temperature range of 540°C for 4 hours. Table 8 shows the physical properties of the antibacterial fired pellets obtained by this molding, and the average strength of the pellets in the table is high, and the apparent density is also high. The effect of using a carbonate such as calcium carbonate in wet molding an antibacterial composition containing zinc or copper is clear from the physical property values listed.

[Table] (a) Antibacterial metal content, % (anhydrous standard)
(b) Antibacterial zeolite powder (dried)
(c) Amount added to b (%)
(d) Addition amount (%) to (b+c)(

[Table] Next, an antibacterial test of the antibacterial composition of the present invention was carried out on both a molded product and a crushed product thereof. The antibacterial activity of the pulverized molded product was evaluated by the following method. The test substance of the crushed product
It was soaked into a disk at a concentration of 100mg/ml. Mueller Hinton medium was used for bacteria, and Sabouraud agar medium was used for fungi. The test bacteria were suspended at 10 ⁸ cells/ml in physiological saline and dispersed in the medium using a 0.1 ml Conlage stick. The test disk was attached onto it. For judgment, the presence or absence of an inhibition zone was observed for bacteria after 18 hours at 37°C. Fungi were determined after one week at 30°C. On the other hand, the fungal mortality rate was measured by the following method. Aspergillus flavus spore suspension ( ¹⁰⁴ pieces/ml)
1 ml of the sample was poured into 9 ml of a suspension of the test substance (500 mg/ml) and allowed to react at 30°C for 24 hours. the
0.1 ml was dispersed on a Sabouraud agar medium, and after 48 hours at 38°C, the number of surviving individuals was measured to determine the mortality rate. Next, the antibacterial activity of the molded body was evaluated using the molded body as a test disk according to the above-mentioned evaluation method, and the fungal mortality rate of the molded body was measured using Aspergillus.
The antibacterial molded body was immersed in a suspension of spores ( ¹⁰⁴ spores/ml) of P. flavus, and the mortality rate was measured according to the method described above. The results of the antibacterial test are shown in Tables 9 and 10. The mortality rate of the antibacterial composition of the present invention against fungi (Aspergillus flavus) is as shown in Table 9, and the bactericidal activity is excellent. Furthermore, Table 10 shows the evaluation results of antibacterial properties regarding four types of bacteria. Comparative example listed in both tables - A is a fine powder of basic copper carbonate [CuCO ₃ · Cu (OH) ₂ · H ₂ O (approximate composition); Cu = 53.2
%], but it was found to be ineffective in all antibacterial tests. Although the copper content in the above powder has reached a high value of 53.2% as indicated, it has no antibacterial activity at all.This is because little research has been done to solve this problem, so it is likely that the antibacterial copper ion This is thought to be due to the fact that no release of On the other hand, in the present invention, antibacterial zinc or copper is stably bonded to zeolite, and in order to increase the strength and density of the molded product, it is combined with a carbonate such as calcium carbonate in the coexistence of a binder. molding, drying, and firing. The antibacterial metal in the fired body is combined with the zeolite and does not form a compound with the carbonate. Therefore, it is thought that zinc and copper ions are rapidly dissociated near the active sites of porous zeolite, and that it is possible to exhibit good antibacterial activity even in the presence of a small amount of antibacterial metals. This point is one of the characteristic advantages of the present invention.

【table】

【table】

[Table] Example 14 This example relates to a water passage test of molded articles (pellets) of the antibacterial composition of the present invention. Example
Antibacterial 1/16″ pellets obtained in 16 (Cu = 2.98%
(Anhydrous standard); = 5.12Kg/pellet; Apparent density =
1.256) Approximately 7 g was collected in a glass column with an inner diameter of 22 mm. After backwashing with water, antibacterial pellets were uniformly filled. Next, add 15 to 20 ml/min of city tap water.
The relationship between the amount of liquid effluent from the column and the copper concentration contained in the effluent was tested by passing water downward at a flow rate of (see Table 11). It was found that the elution of copper takes place in small amounts under favorable conditions (regulatory value for copper when discharging into general rivers: 3 ppm or less). Also during water flow 1/1
There was no damage to the 6" pellets, and the pellets were found to have sufficient water resistance. After 200 water tests, some of the used pellets were tested.
When antibacterial activity against Aspergillus flavus was measured, the mortality rate was 41.8%, confirming that it is still effective.

[Table] Next, the antibacterial 1/16" pellets obtained in Example 12 (Zn = 7.28%; =
Approximately 7 g (6.93 Kg/pellet; apparent density = 1.359) was used. The test conditions are exactly the same as the previous example, so they will be omitted. The results of the water flow test are shown in Table 12, and the zinc concentration in the effluent is maintained at 130 to 190 ppb (regulation value for zinc when discharged into general rivers: 5
ppm or less). Furthermore, no breakage of the 1/16" pellets was observed during the water flow test, and the pellets had good water resistance. After the water flow test, a portion of the used pellets was used to evaluate the mortality rate of Aspergillus flavus. The measured value was 19%.

[Table] The antibacterial composition of the present invention is expected to be sufficiently effective when used not only in the liquid phase but also in the gas phase for the purpose of sterilization.

Claims (1)

[Claims] 1. A molded product of a mixture of alkaline earth metal carbonate and zeolite on which antibacterial metal ions selected from silver ions, zinc ions, copper ions, or mixtures thereof are adsorbed by ion exchange. An antibacterial composition suitable for water treatment consisting of: 2 Water consisting of a mixture of alkaline earth metal carbonate and zeolite on which antibacterial metal ions selected from silver ions, zinc ions, copper ions or mixtures thereof are adsorbed by ion exchange, and a molded binder. Antibacterial composition for treatment. 3. Water or an aqueous urea solution is applied to a composite consisting of a zeolite and a binder on which an antibacterial metal ion selected from an alkaline earth metal carbonate and a silver ion, zinc ion, copper ion or a mixture thereof is adsorbed by ion exchange. Wet blending is carried out in the presence of zeolite, and the resulting mixture is molded into the desired shape, followed by drying, and finally at a temperature range other than the onset of thermal decomposition of carbonates and below the onset of thermal decomposition of zeolite. A method for producing an antimicrobial composition suitable for water treatment, comprising baking in a temperature range. 4. The method according to claim 3, wherein the antibacterial metal is silver. 5. The method according to claim 4, wherein the silver content in the fired body is 0.001 to 20%. 6 Claim 3 in which the antibacterial metal is zinc
The method described in section. 7. The method of claim 6, wherein the zinc content in the fired body is at least 0.04%. 8. The method according to claim 3, wherein the antibacterial metal is copper. 9. The method of claim 8, wherein the copper content in the fired body is at least 0.03%.