JP2017043564A - Bacteriocidal granular material, process for producing bacteriocidal granular material, and liquid spoilage suppressing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a bacteriocidal granular material in which the production cost can be reduced; a process for producing the bacteriocidal granular material; and a liquid spoilage suppressing device.SOLUTION: The bactericidal granular material 10 includes a surface layer 14 on the surface of a granular substrate 12 made of ceramic. The surface layer 14 is formed by calcining a mixture obtained by mixing a water-soluble glass powder, a ceramic powder and a germanium powder into a silver powder, on the surface of the substrate 12. In this case, the surface layer 14 is formed so as to have irregularities on the surface. The bactericidal granular material 10 is placed in a water tank or piping in which it is desired to prevent the growth of bacteria.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a bactericidal granule for sterilizing a liquid, a method for producing a bactericidal granule, and a liquid spoilage suppression apparatus using the bactericidal granule.

  As fungi grow in liquids used in metal processing machines (for example, water-soluble cutting oil and coolant liquid), rot odor is generated, and so far, liquids have been sterilized with antibacterial substances including silver. It was. The antibacterial ceramic body described in Patent Document 1 is one of the conventional antibacterial substances, and has been manufactured by firing a mixture of ceramic powder, silver powder, and water-soluble glass powder. When a liquid is sterilized using this antibacterial ceramic body, the antibacterial ceramic body is formed into a spherical shape and disposed in the liquid.

JP2013-233492A

  In the antibacterial ceramic body described in Patent Document 1, expensive silver is used not only in the surface portion that is easily in contact with the liquid but also in the central portion that is difficult to be in contact with the liquid. was there.

  The present invention has been made to address the above-described problems, and an object thereof is to provide a bactericidal granule capable of reducing the manufacturing cost and a liquid spoilage suppression device using the same.

  In order to achieve the above object, the bactericidal granule according to the present invention is characterized by comprising a granular substrate made of ceramic and a surface layer made of silver-containing water-soluble glass on the surface of the substrate.

  According to this structure, since the base material is formed of an inexpensive ceramic (inexpensive compared with silver), the manufacturing cost of the bactericidal granular material can be reduced. Moreover, the liquid can be sterilized by elution of silver contained in the surface layer together with the water-soluble glass into silver ions (Ag +). In addition, the thickness of the surface layer is 0.1 mm to 1.0 mm, more preferably 0.1 mm to 0.5 mm from the surface of the base material. Moreover, silver nitrate powder is suitable for the silver powder which is powdery silver forming the surface layer. Water-soluble glass is a glass that is soluble by cutting or weakening the irregular network structure of the glass. The dissolution rate is controlled by adjusting the composition in consideration of the physical and chemical properties of the glass. It can be made of glass. For example, water-soluble glass is produced by increasing the amount of modified oxide of the glass and the content of boric acid (boric acid) or phosphoric acid (phosphoric acid), and so-called water glass made of sodium silicate is also water-soluble. Included in glass. The elution amount of silver, elution speed, etc. can be freely controlled by the particle size and amount of use of this water-soluble glass.

  Another feature of the present invention is that, in the bactericidal granules, the surface layer is composed of a fired product of a mixture containing at least powdered silver and powdered water-soluble glass.

  According to another feature of the present invention configured as described above, the bactericidal granules can easily mass-produce bactericidal granules having a surface layer formed on the surface of the substrate.

  Another feature of the present invention is that, in the bactericidal granule, the surface layer further includes a ceramic powder in the mixture.

  According to another aspect of the present invention configured as described above, the sterilizing granular material maintains a necessary sterilizing effect because a part of the surface layer is formed of an inexpensive (less expensive than silver) ceramic. While maintaining the thickness of the surface layer as far as possible, the density (that is, the amount used) of the silver powder in the surface layer can be lowered to reduce the production cost of the bactericidal granules.

  Another feature of the present invention is that in the bactericidal granule, the surface layer further includes at least one of powdered platinum, powdered titanium oxide, and powdered germanium.

  According to another aspect of the present invention thus configured, the disinfectant granule is such that the mixture constituting the surface layer further contains at least one of powdered platinum, powdered titanium oxide, and powdered germanium. Therefore, when platinum is used, the antibacterial action of platinum and the antibacterial action of silver can be combined to obtain a high antibacterial effect. When titanium oxide is used, when titanium oxide is irradiated with light. The catalytic action of titanium oxide and the antibacterial action of silver can be combined to obtain a high antibacterial effect. When germanium is used, the germicidal action of silver can be enhanced by the action of germanium.

  Another feature of the present invention resides in that the base material has a porous surface in the bactericidal granule.

  According to another aspect of the present invention configured as described above, the bactericidal granular material can cause the surface layer to bite into the micropores of the base material formed of the porous ceramic. It becomes easy to form a layer, and the surface layer formed on the surface of the substrate is difficult to peel off, so that the bactericidal effect can be maintained for a long time.

  Another feature of the present invention is that, in the bactericidal granule, the surface layer has a non-uniform thickness from the surface of the base material, and irregularities are formed on the surface of the surface layer. .

  According to another feature of the present invention configured as described above, the surface of the surface layer of the bactericidal granule is uneven, so that the contact area with the liquid is widened, and a plurality of bactericidal particles are formed. When used, gaps can be formed between adjacent sterilizing granular materials to ensure a contact area, and a high sterilizing effect can be obtained. Moreover, since it is not necessary to form an unevenness | corrugation in the surface of a base material, it can manufacture easily. In this case, the difference (that is, the height difference) between the concave portion and the convex portion of the surface layer is preferably 0.1 mm to 0.5 mm.

  Further, the present invention can be implemented not only as an invention of a bactericidal granule, but also as an invention of a method for producing a bactericidal granule and a liquid spoilage suppression apparatus using the bactericidal granule.

  Specifically, the method for producing a bactericidal granule includes a mixture adhering step of adhering a mixture containing at least powdered silver and powdered water-soluble glass to the surface of a granular substrate made of ceramic, A surface layer forming step of forming a surface layer made of a fired product obtained by firing the mixture on the surface. According to this, the same effect as the said bactericidal granule can be expected.

  Further, the liquid spoilage suppression device includes a liquid channel for flowing a liquid and a plurality of bactericidal granules arranged in the liquid in the liquid channel, and each of the plurality of bactericidal granules is made of ceramic. And a surface layer made of silver-containing water-soluble glass on the surface of the substrate so that the thickness of the surface layer is uneven and irregularities are formed on the surface of the surface layer. You can do it.

  According to this configuration, since the liquid spoilage suppression device has irregularities formed on the surface of the surface layer, the contact area with the liquid flowing through the liquid flow path is widened, and a high sterilization effect can be obtained. Further, the liquid easily flows through the recessed portion of the surface layer.

  Further, in this case, the liquid spoilage suppression device further includes a light irradiation device for irradiating the plurality of bactericidal granular materials with light, and the surface layer includes at least powdered silver, powdered water-soluble glass, and It is good to be comprised with the baking products of the mixture containing powdery titanium oxide.

  According to this configuration, when the germicidal granular material is irradiated with light from the light irradiation device, titanium oxide contained in the surface layer exerts a photocatalytic action, so that a high bactericidal effect can be obtained in combination with the silver bactericidal action. it can.

It is sectional drawing which shows the structure of the bactericidal granular material which concerns on one Embodiment of this invention. It is a front view which shows the structure of the liquid decay suppression apparatus which concerns on one Embodiment of this invention.

  Hereinafter, a bactericidal granule and a liquid spoilage suppression device according to the present invention will be described with reference to the drawings.

(Configuration of bactericidal granular material 10)
FIG. 1 is a cross-sectional view showing a configuration of a bactericidal granular material 10 according to an embodiment of the present invention. A sterilizing granular material 10 shown in FIG. 1 is for sterilizing a liquid (for example, a water-soluble cutting oil or a coolant liquid) used in a metal processing machine or the like. And a surface layer 14 formed on the surface.

The base material 12 is formed in a spherical shape having a diameter of about 6 mm from ceramic. The ceramic used in the present embodiment is a porous ceramic mainly composed of alumina (Al ₂ O ₃ ) (92 to 94%), and the substrate 12 is provided with a large number of micropores (not shown). It has been. When the base material 12 is manufactured, magnesia (MgO), kaolin, clay, lime and titanium oxide are mixed with alumina (Al ₂ O ₃ ) as a main component, and these mixtures are formed into a spherical shape. And then fired.

The surface layer 14 is formed in layers on the surface of the substrate 12 by firing silver powder that is powdered silver. The silver powder used in the present embodiment is silver nitrate (AgNO ₃ ) powder, and the surface layer 14 is formed by firing a mixture of the silver powder mixed with ceramic powder, water-soluble glass and germanium powder. As shown in FIG. 1, the thickness of the surface layer 14 is not uniform, and as a result, irregularities are formed on the surface of the surface layer 14.

(Method for producing bactericidal granular material 10)
The manufacturing method of the bactericidal granular material 10 thus configured will be described. First, the operator makes the base material 12 easy. As described above, the base material 12 is formed by firing a sphere having a diameter of about 6 mm whose main material is powdered alumina. In addition to the spherical shape, the base material 12 can be formed in other shapes such as a columnar shape or an irregular gravel shape.

  Next, an operator prepares the mixture which comprises the surface layer 14, and makes it adhere to the surface of the base material 12 (mixture adhesion process). Specifically, the operator is 100 g of silver nitrate powder having a particle size of 10 μm or less, 100 g of water-soluble glass powder (sodium silicate in the present embodiment) having a particle size of 10 μm, and ceramic powder having a particle size of 10 μm or less. (In this embodiment, 100 g of mica) and 2 g of germanium powder having a particle size of 8 μm or less are prepared. In this case, the ratio of each raw material powder is appropriately selected according to the specifications of the bactericidal granular material 10, that is, the degree of elution of silver, the type and concentration of bacteria to be sterilized. The ceramic powder can be mixed up to 10 times the weight of the silver nitrate powder, and the water-soluble glass powder can be mixed up to 100 times the weight of the silver nitrate powder. Moreover, germanium powder can be mixed in the range of 1/100 to 1/50 of silver nitrate powder.

  Subsequently, an operator produces | generates a mixture by stirring and mixing each said raw material powder with an automatic mortar. Next, the operator attaches the mixture to the surface of the substrate 12. In this case, the worker applies an adhesive that adheres the mixture to the surface of the base material 12 to adhere the mixture. As the adhesive, turpentine oil, glaze or water can be used. In this case, the mixture can be non-uniformly adhered to the surface of the substrate 12 by randomly rolling the substrate 12 coated with the adhesive on the mixture.

  Next, an operator forms the surface layer 14 which consists of a small organism of a mixture by baking the mixture adhering to the surface of the base material 12 (surface layer formation process). Specifically, the operator puts the base material 12 to which the mixture is attached into a furnace, heats it at a temperature of 700 ° C. to 800 ° C. for several hours, and then gradually cools the mixture to fire the surface layer 14. Form. In this case, sodium silicate as water-soluble glass powder is softened by heating and functions as a powder binder such as silver nitrate powder. The thickness of the surface layer 14 is preferably 0.1 mm to 0.5 mm from the surface of the substrate 12.

(Usage method of bactericidal granular material 10)
The sterilizable granular material 10 manufactured in this way is installed in a water tank or piping where it is desired to prevent the growth of bacteria. In this case, a plurality of the bactericidal granules 10 are accommodated in an accommodation container that is formed of a mesh or a lattice and ensures water permeability, and is installed in a water tank or a pipe. In this case, the sterilizing granular material 10 may be fixedly accommodated in the storage container, but preferably has a clearance enough to move or change direction in the storage container so that it can float. The sterilizing effect can be further improved by being housed in the container. Moreover, as a place to install the sterilizing granular material 10, a water tank or a pipe for storing water-soluble cutting oil or coolant liquid in a machine tool, a drain hole such as a bathtub or a pipe connected to the bathtub or a sink, and aquatic organisms are bred. There are breeding tanks and septic tanks for use, animal breeding or swimming pools, dehumidifiers, humidifiers, and washing machines.

(Bactericidal effect test of bactericidal granular material 10)
Below, the bactericidal effect test of the bactericidal granules 10 will be described.
[sample]
In this bactericidal effect test, among the bactericidal granules 10 produced by the production method described above, the surface layer having a thickness of 0.1 mm is used as the test product 1 and the surface layer 14 has a thickness of 0.2 mm. This was designated as Test Product 2. Further, a mixture of silver nitrate powder, ceramic powder and germanium powder constituting the surface layer 14 (that is, powder excluding only water-soluble glass powder) was used as a test product 3. Then, 10 g of each of the test products 1 to 3 subjected to high-pressure steam sterilization treatment was prepared, and samples 1 to 3 were prepared by adding 100 ml of sterilized purified water thereto.

[Test method]
Each of samples 1 to 3 was inoculated with 1 ml of a bacterial solution containing the cultured bacteria. Three types of fungi were used: Aspergillus niger spores, Escherichia coli and Staphylococcus aureus. And after leaving for a predetermined time in the environment of predetermined temperature, the number of remaining living microbes was measured. This test was performed twice for each of samples 1-3.

[Test results]
The test results are as shown in Tables 1 to 3 below.

(Effect of this embodiment)
From the above test results, it was found that any of the test products 1 to 3 can obtain an excellent sterilizing effect. Moreover, although the test products 1 and 2 contain the base material 12 which consists of ceramics, it turned out that the bactericidal effect equivalent to the test product 3 comprised only with the powder which does not have the base material 12 can be acquired.

  According to this embodiment, in addition to the above effects, the following effects can be achieved. That is, since the base material 12 shown in FIG. 1 is formed of an inexpensive (inexpensive compared to silver) ceramic, the manufacturing cost of the bactericidal granular material 10 can be reduced.

  The substrate 12 shown in FIG. 1 is formed of a porous ceramic, and the surface layer 14 can bite into the micropores of the substrate 12, so that the surface layer 14 is difficult to peel off from the substrate 12 and sterilizes over a long period of time. The effect can be maintained.

  Since the irregularities are formed on the surface of the surface layer 14 shown in FIG. 1, the contact area with the liquid is widened, and a high sterilizing effect can be obtained. Moreover, since it is not necessary to form an unevenness | corrugation in the surface of the base material 12, it can manufacture easily.

  Since the ceramic contained in the surface layer 14 shown in FIG. 1 functions as a low-cost (low-cost compared to silver) extender, the amount of expensive silver can be reduced to reduce the manufacturing cost of the bactericidal granules 10.

  Since the surface layer 14 shown in FIG. 1 contains germanium together with silver, the sterilization action of silver can be enhanced by the action of germanium, and a high sterilization effect can be obtained. In addition, about the effect | action of such germanium, it describes in detail in Unexamined-Japanese-Patent No. 2012-111710 which concerns on the applicant's patent application. Further, like ceramic, germanium can be used as an extender.

  Since the surface layer 14 shown in FIG. 1 is composed of silver-containing water-soluble glass containing water-soluble glass powder, the silver constituting the surface layer 14 is successively contained in the liquid as the water-soluble glass is eluted in the liquid. The silver ions are released and contacted with each other, and the bactericidal effect can be maintained for a long time.

(Modification)
In carrying out the present invention, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the object of the present invention. For example, in the above embodiment, a ceramic which is a material of the substrate 12, an alumina _(Al 2 _{O 3)} has been a main component, alumina _(Al 2 _{O 3)} instead of with silicon carbide (SiC) or nitride silicon (Si ₃ N ₄ ) or the like may be the main component. Moreover, as a substance added to the main component of the base material 12, one or more of the above magnesia (MgO), kaolin, clay, lime and titanium oxide may be selected and used. It may be used.

  In the above embodiment, when forming the surface layer 14, water-soluble glass powder, ceramic powder, and germanium powder are mixed with silver powder, but at least one of ceramic powder and germanium powder may be omitted. That is, the surface layer 14 can be composed of silver-containing water-soluble glass composed of silver powder and water-soluble glass powder. The ceramic powder that functions as an extender may be a powder other than mica powder, such as alumina oxide.

  Moreover, when forming the surface layer 14, you may mix at least 1 among platinum powder and titanium oxide powder with respect to silver powder. When platinum powder is mixed and a part of the surface layer 14 is formed of platinum, a high bactericidal effect can be obtained by combining a bactericidal action of platinum and a bactericidal action of silver. When titanium oxide powder is mixed and a part of the surface layer 14 is formed of titanium oxide, a high bactericidal effect can be obtained by combining the catalytic action when the titanium oxide is irradiated with light and the bactericidal action of silver. However, in this case, the light irradiation device 26 is required like the liquid decay prevention device 20 shown in FIG.

  When at least one of platinum powder and titanium oxide powder is mixed with silver powder, these can be used as an extender, as in the case of mixing ceramic powder. That is, the manufacturing cost can be reduced as compared with the case where the surface layer 14 is formed only of silver powder.

  The water-soluble glass constituting the surface layer 14 is composed of sodium silicate (so-called water glass) in this embodiment. However, the surface layer 14 should just be comprised with water solubility. Accordingly, the water-soluble glass is formed by other than sodium silicate (so-called water glass), for example, by increasing the amount of the modified oxide of the glass and the content of boric acid (boric acid) or phosphoric acid (phosphoric acid). be able to. The elution amount of silver, elution speed, etc. can be freely controlled by the particle size and amount of use of this water-soluble glass. In addition, the surface layer 14 can also be comprised with water-soluble base materials, such as water-soluble resin (for example, aqueous acrylic resin etc.) other than water-soluble glass.

(Configuration of the liquid spoilage suppression device 20)
FIG. 2 is a front view showing the configuration of the liquid decay inhibiting device 20 according to one embodiment of the present invention. A liquid spoilage suppression device 20 shown in FIG. 2 includes a liquid flow path 22 for flowing the liquid Q, a plurality of bactericidal granules 24 arranged in the liquid in the liquid flow path 22, and a plurality of bactericidal granules 24. A light irradiation device 26 for irradiating light and a pump 28 for circulating the liquid Q are provided. The liquid channel 22 of this embodiment includes a liquid tank 22a for storing the liquid Q, a supply pipe 22b for supplying the liquid Q in the liquid tank 22a to a metal processing machine (not shown), and a metal processing machine (not shown). And a return pipe 22c for returning the liquid Q to the liquid tank 22a. And the pump 28 is provided in the supply pipe | tube 22b, and the several bactericidal granular material 24 is accommodated in the housing 30 arrange | positioned in the liquid tank 22a. The light irradiation device 26 is disposed so as to face the plurality of bactericidal granules 24.

  Each of the plurality of bactericidal granules 24 shown in FIG. 2 is similar to the bactericidal granules 10 shown in FIG. 1, and is a granular substrate (not shown) made of ceramic, and a surface formed on the surface of the substrate. And a layer (not shown). The surface layer is formed by firing a mixture of silver powder and titanium oxide powder. In addition, the thickness of the surface layer is non-uniform, and as a result, irregularities are formed on the surface of the surface layer.

  According to the liquid spoilage suppression device 20 shown in FIG. 2, since the irregularities are formed on the surface of the surface layer constituting the bactericidal granular material 24, the contact area with the liquid Q flowing through the liquid flow path 22 is widened and high. A bactericidal effect can be obtained. Further, the liquid Q easily flows through the recessed portion of the surface layer. Further, when light is irradiated from the light irradiation device 26 to the bactericidal granular material 24, the titanium oxide in the surface layer exhibits a catalytic action, so that a high bactericidal effect can be obtained in combination with the bactericidal action of silver.

  In the liquid spoilage suppression apparatus 20 shown in FIG. 2, the surface layer (not shown) of the sterilizing granular material 24 only needs to contain at least silver and titanium oxide, and the surface layer may further contain other substances. Good.

  Moreover, in the said embodiment, the bactericidal granule 10 was formed with a diameter of 6.2 mm (0.1 mm in height difference) and 6.4 mm (0.1 mm in height difference). However, the bactericidal granular material 10 may have a smooth surface (height difference of 0.1 mm or less) having no irregularities on the surface.

  Moreover, in the said embodiment, although the bactericidal granular material 10 was formed in the substantially spherical shape, if it is a granular material with a magnitude | size of 10 mm or less, shapes other than a spherical shape, for example, a deformed shape with a complicated unevenness | corrugation, a cylinder It may be a shape or a saddle shape.

Q ... Liquid, 10 ... Bactericidal granular material, 12 ... Base material, 14 ... Surface layer,
DESCRIPTION OF SYMBOLS 20 ... Liquid decay suppression apparatus, 22 ... Liquid flow path, 24 ... Bactericidal granular material, 26 ... Light irradiation apparatus

Claims (9)

A granular substrate made of ceramic;
A bactericidal granule comprising a surface layer made of silver-containing water-soluble glass on the surface of the substrate. In the bactericidal granule according to claim 1,
The surface layer is
A bactericidal granule comprising a fired product of a mixture containing at least powdered silver and powdered water-soluble glass. In the bactericidal granule according to claim 1 or claim 2,
The surface layer is
The bactericidal granule according to claim 1, wherein the mixture further contains a powdered ceramic. In the bactericidal granule according to any one of claims 1 to 3,
The surface layer is
The disinfectant granule according to claim 1, wherein the mixture further contains at least one of powdered platinum, powdered titanium oxide, and powdered germanium. In the bactericidal granule according to any one of claims 1 to 3,
The base material has a porous surface, and is a bactericidal granular material. In the bactericidal granule according to any one of claims 1 to 5,
The surface layer has a non-uniform thickness from the surface of the base material and has irregularities formed on the surface of the surface layer. A mixture attaching step of attaching a mixture containing at least powdered silver and powdered water-soluble glass to the surface of a granular substrate made of ceramic;
And a surface layer forming step of forming a surface layer comprising a fired product obtained by firing the mixture on the surface of the base material. A liquid flow path for flowing liquid;
A plurality of bactericidal granules disposed in the liquid of the liquid flow path,
Each of the plurality of bactericidal granules is
A granular substrate made of ceramic;
It has a surface layer made of silver-containing water-soluble glass on the surface of the base material,
A liquid spoilage suppression device, wherein the surface layer has a non-uniform thickness and irregularities are formed on the surface of the surface layer. The liquid spoilage suppression device according to claim 8, further comprising:
A light irradiation device for irradiating the plurality of bactericidal granules with light;
The surface layer is
A liquid spoilage suppression apparatus comprising a fired product of a mixture containing at least powdered silver, powdered water-soluble glass and powdered titanium oxide.

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