JP2000256075A - Antimicrobial porous formed body and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the subject body exhibiting excellent antimicrobial properties and to obtain it with an inexpensive process without need of the process for supporting metal ions. SOLUTION: The antimicrobial porous formed body is obtained by mixing 100 wt.% sepiolite, which is one of inorganic layered clay minerals, and 2 wt.% silver acetate as an antimicrobial metal compound, then, after adding water, kneading the mixture to make it pasty, extruding the paste using a nozzle having the diameter of 4 mm to obtain a formed body having L/D value of 1, after drying the formed body, subjecting the dried formed body to firing treatment by raising temp. at a temp. rising rate of 10 deg.C/min up to 850 deg.C and subjecting to invigoration treatment by blowing steam into for 2 h from the time when the temp. has reached 850 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antibacterial porous molded article having an antibacterial property for killing microorganisms such as Escherichia coli, cerebral germs and Legionella which inhabit water or hot water and a method for producing the same. .

[0002]

2. Description of the Related Art As a conventional example of this type of molded article and its manufacturing method, there is one disclosed in, for example, Japanese Patent Application Laid-Open No. 8-310811. According to this conventional example, a porous sintered body is composed of oyster shell powder, sepiolite, phosphoric acid or phosphate, metal oxide, zeolite carrying calcium ions or copper ions, or calcium phosphate or sepiolite. ing.

[0003]

However, in the case of the prior art, in order to produce a porous sintered body, zeolite supporting silver ions or copper ions and an apatite material supporting a complex salt of silver as calcium phosphate (CaO 2). −P
₃ O ₅ substance), using sepiolite previously substituted with silver ions, mixing them with oyster shell powder and sepiolite,
Further, after adding water and mixing to prepare a molding compound, molding and firing are performed.

[0004] Therefore, a step of supporting silver ions or copper ions, and mixing a zeolite, apatite substance or sepiolite supporting those metal ions with sepiolite or oyster shell powder not supporting metal ions to form a molding compound. And the step of preparing the compound has the drawback of increasing the production cost.

In addition, the molded article lacks uniformity due to the presence of a portion supporting metal ions and a portion not supporting metal ions.
There was a drawback that stable antibacterial properties could not be exhibited.

The present invention has been made in view of such circumstances, and has as its object to eliminate the need for a step of supporting metal ions and to obtain the antibacterial property at a low cost. I do.

[0007]

According to a first aspect of the present invention, there is provided an antibacterial porous molded article, comprising: a porous molded article made of carbon, ceramic, or a mixture of carbon and ceramic; Antibacterial metal
It is characterized by being mixed at 0.01 to 20% by weight.

[0008] The antibacterial metal may be a metal such as silver, copper, titanium or zinc, or a metal containing at least one of carbides, nitrides and oxides thereof. An organometallic complex or a metal salt of these metals may be used, and the organometallic complex or the metal salt may be added and mixed at the time of mixing the organic sintering agent and the inorganic layered clay mineral, or a petroleum pitch or coal may be used in advance. Either a system pitch or a method of dispersing and mixing in a thermosetting resin may be used.

Further, the added and mixed organometallic complex or metal salt is decomposed in the firing and activation temperature range of the molded product,
Metals such as silver, copper, titanium and zinc, and their carbides, nitrides and oxides. The organometallic complex or metal salt dispersed and mixed in petroleum pitch, coal pitch or thermosetting resin in advance may be, depending on the processing temperature after mixing, metals such as silver, copper, titanium, and zinc, and those metals. May be changed to carbides, nitrides, and oxides.

[0010] The content of the antibacterial metal in the antibacterial porous molded body may be 0.01 to 20% by weight, preferably 0.1 to 10% by weight, in terms of metal. If the amount is less than 0.01% by weight, it is difficult to obtain the antibacterial effect, while if it exceeds 20% by weight, the production cost of the antibacterial porous molded body increases.

Further, the method for producing an antibacterial porous molded article according to the third aspect of the present invention is intended to achieve one of the above objects by at least one of petroleum pitch, coal pitch and thermosetting resin. More than one kind of powder, silver, copper, one or more metals of titanium or zinc, and after adding an organometallic complex or a metal salt of the metal, further adding water or a hydrophilic organic solvent to form a paste. Molded and the molded body 500 ~
It is characterized by firing and activation at 1000 ° C.

The softening point of petroleum pitch and coal pitch is 100 to 400 ° C., preferably 200 to 300 ° C.,
An optically isotropic structure is desirable. If the temperature is lower than 100 ° C., the amount of low-boiling components is so large that the infusibilization treatment is difficult, and the shape of the molded body cannot be maintained at the temperature in the firing and activation treatments. on the other hand,
If the temperature exceeds 400 ° C., the proportion of the optically anisotropic structure occupies a large amount, and sufficient pores cannot be obtained in the activation treatment of the molded product, and only a molded product having a small specific surface area can be obtained. As the thermosetting resin, generally available resins such as a phenol resin, a melamine resin, and a polyurethane can be used. Further, as the hydrophilic organic solvent, alcohol and the like can be applied.

In order to achieve the above-mentioned object, the method for producing an antibacterial porous molded article according to the present invention provides a method for producing a powder of an inorganic layered clay mineral and a method of producing a powder of silver, copper, titanium or zinc. One or more of these metals and an organometallic complex or a metal salt of the metal are added, and water or a hydrophilic organic solvent is further added to form a paste, which is then molded.
It is characterized by firing and activation treatment at 0 to 1000 ° C.

As the inorganic layered clay mineral, zeolite,
Sepiolite, diatomaceous earth, kaolin, montmorillonite,
What has sinterability, such as talc, can be applied. After the firing and the activation treatment, the layers between the ceramic particles function as appropriate pores and are rich in hydrophilicity, so that there is an advantage that a liquid or a gas easily permeates.

In order to achieve the above-mentioned object, the method for producing an antibacterial porous molded article according to the fifth aspect of the present invention comprises one of petroleum pitch, coal pitch or thermosetting resin. Powders of more than one kind, powders of inorganic layered clay minerals, silver, copper, one or more metals of titanium or zinc, and an organometallic complex or metal salt of the metal, and further water or a hydrophilic organic solvent And then molded into a paste, and then molded and fired at 500 to 1000 ° C. and activated.

The interlayer of the inorganic layered clay mineral has a heating temperature of 5
Since the adsorptivity is maintained without changing up to 00 ° C,
Volatile components and sublimation components generated when heating petroleum-based pitch, coal-based pitch, or thermosetting resin are adsorbed by the inorganic layered clay mineral, thereby preventing sticking (fusion) of the molded products to each other. It has the function of simplifying the melting process.

Furthermore, the volatile component and the sublimation component adsorbed on the inorganic layered clay mineral are carbonized in the firing and activation stages, and the carbon and the ceramic are sintered more strongly, so that a molded body having high mechanical strength is obtained. At the same time, the layers between the ceramic particles function as appropriate pores, and are rich in hydrophilicity. Therefore, there is an advantage that a liquid or a gas easily permeates.

The petroleum-based pitch, coal-based pitch, thermosetting resin, inorganic layered clay mineral, antibacterial metal and its compound may be used in powder form. Smaller is better, but usually 1
It may be 50 microns or less.

A hydrophilic organic solvent such as water or alcohol is appropriately added to the powder and the mixed powder, kneaded to form a paste, and then subjected to a general production method, for example, extrusion molding, rolling molding, extrusion. A molded body is obtained by a method such as post-rolling molding and pressure molding.

[0020] Further, starch,
Glue and synthetic resin such as methylcellulose, polyethylene, polyvinyl alcohol, cellulose, etc.
By adding 20% by weight, drying of the molded body, infusibility treatment,
There is an effect that the shape is easily maintained in the steps of the firing and the activation treatment, and the number of open pores of the molded body after the activation treatment is increased.

The condition of the infusibilizing treatment may be a known condition, for example, from room temperature to 400 ° C. in an active atmosphere such as air or ozone.
The treatment may be performed in a temperature range of ° C. The time of the infusibilization treatment varies depending on the softening point of the pitch used, the size of the molded body, and the like. Usually, however, if the infusibilization treatment is performed so that the oxygen content of the molded body becomes about 3 to 15% by weight. good. If the oxygen content of the molded body after the infusibilizing treatment is too small, the petroleum pitch, the coal pitch or the thermosetting resin is melted at the stage of the firing and activation treatment, and the shape of the molded body cannot be maintained. On the other hand, if the oxygen content is too large, petroleum pitch, coal pitch or thermosetting resin will not melt at all in the stage of firing and activation treatment, sinterability can be obtained, low mechanical strength This is because it becomes a molded body.

The molded body subjected to the infusibilization treatment is then subjected to a baking and activation treatment to become a porous and antibacterial molded body. Firing is usually performed in an inert atmosphere such as nitrogen.
It may be carried out by heating to a temperature of 500 to 1000 ° C, preferably about 700 to 900 ° C. The activation treatment may be performed by a generally known method such as a gas activation method. For example, steam, carbon dioxide, oxygen, and a mixed gas thereof, or an atmosphere in which these gases are diluted with nitrogen or the like, at a temperature of 500 to 1000 ° C., preferably 700 to 9
The activation treatment can be performed by heating to a temperature of about 00 ° C. The activation time varies depending on the size of the molded body and the like, but is usually preferably about 5 to 600 minutes. Further, it is not necessary to separately perform the firing treatment and the activation treatment. When the activation treatment is performed under the above conditions, the firing is performed at the same time. If the temperature of firing and activation is 500 ° C or less, carbonization of organic substances such as petroleum pitch, coal pitch and thermosetting resin, and activation hardly proceed, and it takes a long time for the treatment, so that it is not practical. Absent. On the other hand, when the treatment is performed at a temperature higher than 1000 ° C., the activation is excessively advanced, so that adjustment for obtaining a target product is difficult, and it is difficult to obtain a product with stable quality.

[0023]

According to the structure of the antibacterial porous molded body of the invention according to the first aspect, pores formed in carbon, ceramic, or a mixture of carbon and ceramic come into contact with an object to be treated such as water. The surface area increases, and bacteria such as Escherichia coli in the object to be treated come into contact with the antibacterial metal mixed in the molded body, and the bacteria are killed.

Further, according to the construction of the method for producing an antibacterial porous molded product according to the third aspect of the present invention, sufficient pores can be obtained by firing and activating treatment, and contact with an object to be treated such as water can be achieved. The surface area of the material to be treated increases, and bacteria such as Escherichia coli in the object to be treated come into contact with the antibacterial metal mixed in the molded body, and the bacteria are killed.

Further, according to the construction of the method for manufacturing an antibacterial porous molded article of the invention according to claim 4, by baking and activating, the ceramic particles function as appropriate pores between the layers and have high hydrophilicity. Thus, an object to be treated such as water easily permeates, and bacteria such as Escherichia coli in the object to be treated come into contact with the antibacterial metal mixed in the molded body, and the bacteria are killed.

Further, according to the construction of the method for producing an antibacterial porous molded article of the invention according to claim 5, sufficient pores are obtained by firing and activation treatment, and appropriate pores are formed between layers of the ceramic particles. The material to be treated, such as water, is easy to permeate because it is rich in hydrophilicity, and bacteria such as Escherichia coli in the material to be treated come into contact with the antibacterial metal mixed in the molded body,
The bacteria die.

[0027]

Next, embodiments of the present invention will be described in detail.

<Example 1> 100% by weight of sepiolite, which is an inorganic layered clay mineral, and 2% by weight of silver acetate as an antibacterial metal were mixed, and water was added thereto, followed by stirring and mixing to form a paste. Extruded from the nozzle of L / D
A molded body having a ratio of (length to diameter) of 1 was obtained. After the molded body is dried, it is heated to 850 ° C at a rate of 10 ° C / min in a nitrogen atmosphere and fired. When the temperature reaches 850 ° C, steam is blown in for 2 hours to activate the antibacterial. A porous molded article was obtained.

Example 2 20% by weight of coal-based pitch powder having a softening point of 282.6 ° C., a quinoline-insoluble content of 20.3% by weight, and a toluene-insoluble content of 74.3% by weight, 80% by weight of montmorillonite which is an inorganic layered clay mineral, and an antibacterial metal Acetate as weight 2% by weight
And water were added thereto, and the mixture was stirred and mixed to form a paste, and then extruded from a 4 mm nozzle to obtain a molded body having an L / D of 1. After the molded body is dried, it is heated to 850 ° C at a rate of 10 ° C / min in a nitrogen atmosphere and fired. When the temperature reaches 850 ° C, steam is blown in for 2 hours to activate the antibacterial. A porous molded article was obtained.

Example 3 50% by weight of coal-based pitch powder having a softening point of 282.6 ° C., a quinoline-insoluble content of 20.3% by weight and a toluene-insoluble content of 74.3% by weight, 50% by weight of bentonite as an inorganic layered clay mineral, and an antibacterial metal Was mixed with 1.5% by weight of silver acetate, water was added, and the mixture was stirred and mixed to form a paste, and then extruded from a 4 mm nozzle to obtain a molded product having an L / D of 1. After the molded body is dried, the temperature is raised from room temperature to 330 ° C. at a rate of 2 ° C./min in a nitrogen atmosphere, and the mixture is kept at 330 ° C. for 2 hours to perform infusibility treatment. The temperature was raised to 850 ° C. at a rate of 10 ° C./min to perform a baking treatment. When the temperature reached 850 ° C., steam was blown for 2 hours to perform an activation treatment to obtain an antibacterial porous molded body.

Example 4 80% by weight of coal-based pitch powder having a softening point of 282.6 ° C., a quinoline-insoluble content of 20.3% by weight, and a toluene-insoluble content of 74.3% by weight, 20% by weight of sepiolite, an inorganic layered clay mineral, and an antibacterial metal Was mixed with 1% by weight of silver acetate, and water was added thereto, followed by stirring and mixing to form a paste, and then extruded from a 4 mm nozzle to obtain a molded product having an L / D of 1. After the molded body is dried, the temperature is raised from room temperature to 330 ° C. at a rate of 2 ° C./min in a nitrogen atmosphere, and the mixture is kept at 330 ° C. for 2 hours to perform infusibility treatment. The temperature was raised to 850 ° C. at a rate of 10 ° C./min to perform a baking treatment. When the temperature reached 850 ° C., steam was blown for 2 hours to perform an activation treatment to obtain an antibacterial porous molded body.

<Example 5> 100% by weight of coal pitch powder having a softening point of 282.6 ° C, a quinoline-insoluble content of 20.3% by weight, and a toluene-insoluble content of 74.3% by weight, and 1% by weight of silver acetate as an antibacterial metal were mixed. Then, water was added, and the mixture was stirred and mixed to form a paste, and then extruded from a 4 mm nozzle to obtain a molded body having an L / D of 1. After the molded body is dried, the temperature is increased from room temperature to 330 ° C. at a rate of 2 ° C./min in a nitrogen atmosphere, and further maintained at 330 ° C. for 2 hours for infusibility treatment.
Thereafter, the temperature is increased to 850 in a nitrogen atmosphere at a rate of 10 ° C / min.
When the temperature reached 850 ° C., steam was blown for 2 hours to perform an activation treatment to obtain an antibacterial porous molded body.

The activation yield (% by weight), specific surface area (m ² / g) and silver concentration (% by weight) of each of the above Examples are as shown in Table 1. The mixing ratio is also shown.

[0034]

[Table 1]

Each of the molded articles of the above Examples was pulverized, and a part thereof was subjected to an antibacterial confirmation test. The measuring method is as follows. That is, sterile water containing 10 ⁶ cfu of E. coli 1
Add 0.03 g of antibacterial adsorbent crushed to 00 ml, and add
Shake for a minute. After 4 hours, 6 hours, 12 hours and 24 hours after the end of shaking, collect 1 ml of sterilized water at a time,
After dilution, 100 μl was applied to soybean casein digest agar medium. This was allowed to stand at 37 ° C. for 5 days and cultured, and the number of bacteria was measured. Table 2 shows the results.

[0036]

[Table 2]

Comparative Example 1 A commercially available specific surface area of 1120 m ² /
g, 100 parts by weight of powdered activated carbon having a silver impregnation amount of 0.98% by weight, phenol resin was mixed with 20 parts by weight, water was added and mixed by stirring to form a paste, and then extruded from a 4 mm nozzle. A molded product having a / D of 1 was obtained. After drying the molded body, the temperature is increased from room temperature to 500 ° C. at a rate of 2 ° C./min in a nitrogen atmosphere, and further increased from 500 ° C. to 800 ° C. at a rate of 10 ° C./min. Upon reaching, activation treatment was performed by blowing steam for 30 minutes. Specific surface area after treatment is 880m ² / g, silver concentration is 1.1% by weight
Met. When a test for confirming the antibacterial activity was performed using this comparative example 1 in the same manner as in the above-mentioned example, Table 3
The result shown in FIG.

[0038]

[Table 3]

Example 6 12 g of silver acetate was added to 100 ml of quinoline
, And the whole amount was added to 1.0 kg of coal tar and mixed. The mixture is distilled to remove light components in quinoline and coal tar, and a pitch having a softening point of 83.4 ° C is added to the mixture.
g was obtained. The entire pitch is charged to an autoclave and 3
At a temperature of 30 ° C, air is blown at a rate of 5 liters / minute,
423 g of a pitch having a softening point of 284.8 ° C. was obtained. The silver concentration of this pitch was 1.84% by weight. Next, the pitch and the sepiolite were mixed at the same ratio, water was added, and the mixture was stirred and mixed to form a paste. Then, the same treatment as in the above-described example was performed, and the specific surface area was 320 m ² / g, an antibacterial porous molded body having a silver concentration of 1.10% by weight. Further, an antibacterial property confirmation test was performed using the molded article of Example 6 in the same manner as in the above-mentioned Example, and the results shown in Table 4 were obtained.

[0040]

[Table 4]

From the above results, it was clear that all of the examples can kill E. coli in an extremely short time as compared with the comparative example and are excellent in antibacterial properties.

The shape of the antibacterial porous molded product of the present invention may be processed into various shapes such as a spherical shape, a pellet shape, a Raschig ring shape, a plate shape, a honeycomb shape and a block shape depending on the use.

In the above embodiment, silver is used as the antibacterial metal. However, the present invention includes, for example, copper, titanium,
Zinc, their carbides, nitrides, oxides, or a mixture of a plurality of them may be used.

[0044]

As is apparent from the above description, according to the antibacterial porous molded article of the first aspect, the antibacterial metal is mixed with carbon, ceramic, or a mixture of carbon and ceramic. As a result, the step of supporting metal ions as in the related art can be omitted, so that an antibacterial porous molded body can be obtained at low cost. Moreover, pores formed in carbon, ceramic, or a mixture of carbon and ceramic increase the surface area in contact with the object to be treated, such as water, and cause the antibacterial metal mixed in the molded body to contain the antibacterial metal in the object. Bacteria, such as Escherichia coli, can easily come into contact with each other, and can exhibit excellent antibacterial properties.

Further, according to the method for producing an antibacterial porous molded article of the invention according to the third aspect, a mixing step, a firing step, and an activation step are only performed, thereby eliminating the step of carrying metal ions as in the prior art. As a result, an antibacterial porous molded article can be obtained at low cost. Moreover, sufficient pores can be obtained by calcination and activation treatment, the surface area in contact with the object to be treated such as water is increased, and the antibacterial metal mixed in the molded body has a large amount of E. coli and the like in the object to be treated. Bacteria are easy to contact and can exhibit excellent antibacterial properties.

According to the method for producing an antibacterial porous molded product of the invention according to the fourth aspect, similarly to the invention according to the third aspect, only the mixing, sintering and activation treatments are carried out. Since the step of supporting a metal ion can be omitted, an antibacterial porous molded body can be obtained at low cost. In addition, the baking and activation treatments serve as appropriate pores between the layers of the ceramic particles, and the material to be treated such as water is rich in hydrophilicity and easily penetrates. Bacteria such as Escherichia coli in the processed product are easily contacted, and excellent antibacterial properties can be exhibited.

According to the method for producing an antibacterial porous molded article of the invention according to claim 5, as in the invention according to claims 3 and 4, only the mixing treatment, the calcination and the activation treatment are performed. Since the step of carrying metal ions as in the prior art can be dispensed with, the antibacterial porous molded body can be obtained at low cost. Moreover, by firing and activation treatment,
In addition to obtaining sufficient pores, it acts as an appropriate pore between the layers of the ceramic particles, and is easy to penetrate the treatment object such as water, which is rich in hydrophilicity, and covers the antibacterial metal mixed in the molded body. Bacteria such as Escherichia coli in the processed product are easily contacted, and excellent antibacterial properties can be exhibited. In addition, the volatile component and the sublimation component adsorbed on the inorganic layered clay mineral are carbonized in the firing and activation stages, so that the carbon and the ceramic are more strongly sintered and the mechanical strength can be improved.

Claims (5)

[Claims] 1. An antibacterial porous molded body characterized in that a porous molded body molded from carbon, ceramic, or a mixture of carbon and ceramic is mixed with an antibacterial metal in an amount of 0.01 to 20% by weight. 2. The antibacterial metal according to claim 1, wherein the antibacterial metal is silver,
Copper, titanium, zinc, or their carbides, nitrides,
An antibacterial porous molded article comprising one or more oxides. 3. A powder of at least one of petroleum pitch, coal pitch or thermosetting resin, at least one metal of silver, copper, titanium or zinc, and an organometallic complex of said metal Or adding a metal salt, further adding water or a hydrophilic organic solvent to form a paste, and then molding the molded article, and baking and activating the molded article at 500 to 1000 ° C. to form an antibacterial porous molded article. Production method. 4. An inorganic layered clay mineral powder, at least one metal selected from the group consisting of silver, copper, titanium and zinc, and an organometallic complex or metal salt of the metal are added, and water or a hydrophilic organic solvent is further added. In addition, a method for producing an antibacterial porous molded body, comprising forming the paste into a paste, molding the molded body, and firing and activating the molded body at 500 to 1000 ° C. 5. A powder of one or more of petroleum-based pitch, coal-based pitch or thermosetting resin, a powder of an inorganic layered clay mineral, and a metal of one or more of silver, copper, titanium or zinc And adding the organometallic complex or metal salt of the metal, further adding water or a hydrophilic organic solvent to form a paste, and then molding, and firing and activating the molded body at 500 to 1000 ° C. A method for producing an antibacterial porous molded article.