JP2005126348A - Metal-based inorganic antibacterial and antifungal agent, method for producing the same and use - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antibacterial and antifungal agent which can efficiently and strongly be adhered and coated to a material to be treated, such as fibers, plastic, ceramic, or metal, in a small amount at a low cost by an environmental load-lowering treating method not needing the treatment of a waste liquid and the like, to provide a method for adhering or coating the same to a material to be treated, and to provide an antibacterial and antifungal material obtained by the method. <P>SOLUTION: This antibacterial and antifungal agent is characterized by comprising as an active ingredient a nanometer order aerosol prepared by dispersing a metal, such as silver, or its compound having an antibacterial and antifungal action by a heating treatment or a chemical reaction under the atmospheric pressure in the gas phase. The method for adhering or coating the antibacterial and antifungal metal to the material to be treated comprises strongly and efficiently adhering and coating the metal to the material to be treated in a small amount by an environmental load-lowering treating method not needing the treatment of a waste liquid and the like and utilizing the nano-particle specificity, thermal adhesion force or electrostatic adhesion force of the antibacterial and antifungal agent. The antibacterial and antifungal material is characterized by strongly adhering or coating the metal to the material to be treated. And an application product thereof is provided. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a novel metal-based inorganic antibacterial / antifungal agent having an antibacterial / antifungal action and containing a metal such as silver as an active ingredient, which is produced by applying nanotechnology, the antibacterial / antifungal agent as a fiber, plastic And a method of bringing the metal into contact with and covering the material to be treated, an antibacterial / antifungal material produced by the method, and using the antibacterial / antifungal material The present invention relates to an article having an antibacterial / antifungal function.

  In recent years, damage caused by resistant bacteria such as MRSA resulting from heavy use of antibiotics has become a problem, and inorganic germicides and antibacterial agents that are not organic are being reviewed. The main reason is that metal oxides such as silver and metal oxides such as titanium oxide do not necessarily show a strong bactericidal action, but do not generate resistant bacteria and are harmless to the human body. It has a long-lasting antibacterial and antifungal action on fungi and the like, and this has been well known since history.

  Antibacterial agents using antibacterial metals are already widely used as commercial products. For example, trade names with silver added include Bactekiller (Kanebo, Zeolite), Iopure (Ishizuka Glass, Glass), Novalon (Toagosei, main component: silver zirconium phosphate), Zeomic (Shinagawa Fuel, main component: silver) Zeolite), Zeoplus (Matsumoto Yushi, Silver Zeolite), AM15 for ceramics (Sumitomo Osaka Cement, Silver), and Gintech (Kawakaku Giken, silver-coated titanium oxide). The method of adding silver in these products includes a method of adsorbing silver ions to an adsorbent such as zeolite, a method of dispersing silver powder in a solvent such as glaze, a method of electrically or chemically reducing silver compounds (including plating), Are all based on the liquid phase method.

  Examples of the antibacterial material to which the antibacterial agent is added include natural fibers, chemical fibers, ceramics, plastics, and metals. Among these, as a recent trend, products using polymer materials such as plastics are widely used, and plastics are surpassing ceramics and metal products due to their ease of molding and low cost. For this reason, antibacterial agents that can be used for plastics polymer materials including chemical fibers and the low-cost addition method thereof need to be particularly studied.

As a method for adding the antibacterial agent to the antibacterial material, in the case of ceramics, mixing with a glaze, and in the case of metal, baking adhesion to the surface is preferable from the viewpoint of efficiency and adhesion strength.
Both are forms close to surface addition, and their implementation is relatively easy. On the other hand, in the case of polymers such as plastics, since there is no heat resistance, after mixing with raw materials in advance, a process such as molding (kneading method), and after molding a product containing silver-containing material There are methods to adhere and coat.
The antibacterial action is considered to be only the antibacterial agent on the surface, so in the method of mixing and kneading, the antibacterial agent inside the product material does not contribute to the antibacterial effect, but it contains it If the amount is increased, there is a risk of negative effects such as alteration of product materials. Moreover, since silver is expensive, the high cost cannot be neglected.

On the other hand, the method of attaching / coating the antibacterial agent to the surface of the antibacterial material is efficient in terms of cost, but the technology up to now has low adhesion / coating strength, for example, detachment (peeling of components) during washing. ) And there is a problem in the durability of antibacterial action. However, the surface adhesion / coating method is preferable as long as it is possible to improve the adhesion strength without causing desorption. In particular, silver is effective from the viewpoint of cost.
As a method for attaching and coating the antibacterial agent on the surface of the antibacterial material, there are a dry method in which silver powder is directly attached to the antibacterial material and a wet method such as plating. Specifically, dry methods include a method in which silver powder is directly adhered to an antibacterial material, a vacuum deposition method, and a sputtering method. However, a method that requires reduced pressure is not practical from the viewpoint of cost.
In the method of spraying silver powder directly on the surface of the antibacterial material, the production lower limit particle size of the commercially available silver powder is micron, so that the surface adhesion strength is weak and there is a risk of desorption of components. For this reason, in order to raise the adhesion strength, the proposal of adhesion operation near the softening point temperature of antibacterial materials, such as a polymer, is also seen (for example, refer to patent documents 1).

On the other hand, as a wet method, for example, there is a silver compound reduction method represented by plating (for example, see Patent Document 2). However, plating is effective for metals and the like, but is not effective for polymer materials such as plastics. For plastics, there is an electroless plating method or the like, but the process becomes complicated and the adhesion strength is also weaker than plating on metal. In order to increase the adhesion strength, a method of immersing in a fine powder antibacterial metal colloid solution containing a binder (see, for example, Patent Document 3) has also been proposed. However, most of all, in the wet method, waste liquid treatment and drying process are indispensable, so environmental load and high cost must be considered.
JP-A-11-269277 JP-A-8-99812 JP 2000-178870 A

Under such circumstances, the present inventor, in view of the above-mentioned prior art, has developed a method for efficiently and firmly attaching and coating metal particles such as silver having antibacterial and antifungal effects on a material to be treated. As a result of intensive research with the goal of developing, it was found that the intended purpose can be achieved by adopting a method of using metal in the gas phase, dispersing and aerosolizing, and conducting further research The present invention has been completed.
The present invention relates to an antibacterial / antifungal agent comprising as an active ingredient an aerosol obtained by converting an antibacterial metal into a gas phase microaerosol, a method for producing the same, and attaching / covering the antibacterial / antifungal agent on a material to be treated. It is intended to provide antibacterial and antifungal materials and their applied products.

The present invention for solving the above-described problems comprises the following technical means.
(1) A metal-based inorganic antibacterial / antifungal agent characterized by using an aerosol as an active ingredient, which is obtained by converting an antibacterial metal into a gas phase micro aerosol.
(2) The metal-based inorganic antibacterial / antifungal agent according to (1), wherein a metal or a metal compound is vaporized and dispersed to form an aerosol under atmospheric pressure by heating or chemical reaction.
(3) The metal-based inorganic antibacterial / antifungal agent according to (1) or (2), wherein the metal is one or more of silver, copper, and zinc.
(4) The metal-based inorganic antibacterial / antifungal agent according to (1) or (2), wherein the average particle size of the aerosol is 0.001 to 0.5 μm.
(5) A metal or a metal compound is formed into an aerosol in which a metal is vapor-phase / dispersed by heating or a chemical reaction under atmospheric pressure, and the metal is brought into contact with the material to be treated by bringing the aerosol into contact with the material to be treated. Antibacterial and antifungal material characterized by being attached to and coated on
(6) The antibacterial / antifungal material according to (5) above, wherein an aerosol heated to a temperature at which the material to be treated is not deteriorated is brought into contact with the material to be treated.
(7) The antibacterial / antifungal material according to (5) above, wherein the aerosol is charged and adhered to and coated on the material to be treated by electrostatic force with the material to be treated.
(8) The metal-based inorganic antibacterial / antifungal material according to any one of (5) to (7) above, wherein the average particle size of the aerosol is 0.001 to 0.5 μm.
(9) An antibacterial / antifungal metal is produced by forming a metal or a metal compound into an aerosol in which the metal is in a gas phase / dispersion by heating or chemical reaction under atmospheric pressure, and bringing the aerosol into contact with the material to be treated. An antibacterial / antifungal metal adhesion / coating method characterized by adhering / coating a material to a treated material.
(10) The method according to (9), wherein the treated material is contacted with an aerosol heated to a temperature at which the treated material does not change in quality.
(11) The method according to (9), wherein the aerosol is charged and adhered to and coated on the material to be treated by electrostatic force with the material to be treated.
(12) The method according to any one of (9) to (11) above, wherein the average particle size of the aerosol is 0.001 to 0.5 μm.
(13) An article provided with an antibacterial / antifungal function, comprising the antibacterial / antifungal material according to any one of (5) to (8) as a constituent element.

Next, the present invention will be described in more detail.
In the present invention, a metal such as silver having an antibacterial / antifungal action or a compound thereof is heated or subjected to a chemical reaction at atmospheric pressure to form a gas phase / dispersed fine aerosol of the metal, for example, ceramics, plastics, Contact with a material to be treated such as natural fiber, chemical fiber, metal, etc., and adhere to and coat the material to be treated, so that the antibacterial / antifungal agent of silver or other antibacterial metal is fully exerted. It is characterized by.

In the present invention, the method for attaching and coating the antibacterial metal to the material to be treated is a dry method, and there is no environmental load such as waste liquid treatment as long as the generated aerosol is completely used. Even if the generated aerosol is not completely used, it can be removed with a simple filtration device.
The material to be treated used in the present invention is an object to be treated with the antibacterial / antifungal agent of the present invention, and may be a carrier. Specifically, the above-mentioned materials such as ceramics, plastics, natural fibers, chemical fibers, metals, and the like, and a combination of two or more of them, an article having a specific shape or a part of the article Illustrated. Examples of the article having the specific shape include, for example, processed products such as woven fabrics, non-woven fabrics, granular materials, films, and plate-like products, clothing items such as socks, underwear, and slacks, and daily items such as towels and containers, Examples of such materials have conventionally required antibacterial and antifungal properties, such as building materials such as wall materials, medical and sanitary tools used in hospitals, homes, and the like.

Examples of the metal used in the present invention include silver, copper, and zinc. Among these, silver is preferable in consideration of antibacterial properties, cost, safety to the human body and ease of handling.
In the present invention, the micro aerosol is produced by directly heating a metal such as silver, copper, or zinc, or by vapor phase decomposition of these organometallic compounds. For example, when the fine metal particles are heated, the fine metal particles having an arbitrary particle size of, for example, a micron size can be easily produced by simply adjusting the power supply amount.

By the way, the antibacterial action of the metal antibacterial agent depends on the surface area thereof, and the effect increases in proportion to the increase in the surface area. Therefore, the miniaturization of the aerosol is not only effective for improving the antibacterial effect, but also very effective for reducing the cost. For example, if a silver particle having an average diameter of 1 micron is 10 nanometers (nm), the surface area becomes 100 times, that is, 100 times as much as the same amount of silver used. It shows that an amount of 1/100 is sufficient to produce an effect. In particular, miniaturization in the case of silver is effective in reducing the cost.
As described above, the smaller the particle size of the metal fine particles, the larger the specific surface area. However, the lower limit of the particle size of the metal fine particles is several nanometers. Considering the low temperature liquefaction phenomenon, it is about 100 nanometers or less, preferably 50-60 nanometers or less.

When the particle size of the antibacterial agent particle becomes a visible light wavelength (about 500 nanometers) or less, the antibacterial agent particle becomes transparent to visible light and affects the aesthetics of the product to which the antibacterial agent particle is applied. For example, when the antibacterial agent is silver having an excellent antibacterial effect, there is an aesthetic problem of browning with the addition of the antibacterial agent. On the other hand, it becomes transparent, and the problem of browning does not occur, and it becomes suitable for the manufacture of products using materials such as lenses and glass where transparency is important. In order not to make the visible light transmittance too low, the particle size of the metal fine particles is set to a wavelength of visible light or less, preferably 0.3 μm or less.
Regarding the formation of fine particles of inorganic antibacterial agents such as metals, a wet liquid phase method by reduction of metal compounds has been proposed (for example, JP-A-8-99812), and the effects thereof are also described in detail. However, in the wet method, as described above, not only the problem of adhesion strength but also the high cost due to the additional steps of the waste liquid treatment and the drying process cannot be denied.

The microparticulation of the antibacterial agent by the dry method of the present invention not only makes these additional treatments unnecessary, but also brings about the following excellent effects.
Metals are generally recognized as high melting point substances, but when the size is reduced to a nanometer size, the phenomenon that the melting point decreases due to surface activity or the like is observed. For example, in the case of silver, when it is miniaturized to 10 to 20 nanometers, it is considered that its melting point decreases to about 100 to 200 ° C. (By the way, the melting point of massive silver is 950 ° C.). In other words, the metal particles in the gas phase are reduced in size to the nanometer scale, which indicates that the metal particles are easily liquefied at a low temperature due to the melting point drop.

By the way, the adhesion form of the antibacterial fine particles to the base material (the material to be treated) is completely different between a solid case and a liquid case. In a solid, it is in a state close to point contact, but when it is in a liquid state, it is considered to adhere to a surface. That is, it shows that the adhesion strength is much stronger, and this is one of the main elements forming the basis of the present invention.
In an actual embodiment, for example, antibacterial fine particles (metal fine particles) having a particle size smaller than the particle size liquefied at the aerosol-containing gas temperature corresponding to the heat resistance limit of the material to be processed are manufactured, and the material to be processed is liquid. It will be attached and covered.
Here, when the heat-resistant limit of the material to be treated is 200 to 300 ° C., the metal particle diameter depends on whether the particle structure is crystalline or amorphous, but is preferably about 100 nanometers or less, preferably Is suitably 50 to 60 nanometers or less.

For reference, FIG. 1 is an electron micrograph of silver aerosol fine particles in an antibacterial / antifungal material produced by the method of Example 4 described later. From this photograph, it can be seen that it is isolated and dispersed. The average particle size in this case is about 3 nanometers. Further, when the photograph is observed in detail, a fine undulation pattern of the sample substrate (polymer thin film) is observed through the attached aerosol particle image. This tells us that it was in liquid form.
The sampling conditions for this sample are silver particles having an average particle diameter of about 3 nm so that the liquid silver particles are sufficiently liquid even at a temperature lower than that in consideration of the softening point of the polymer thin film on the sample substrate. Yes.
The above is a feature that cannot be performed by a wet method such as a metal compound reduction method by a liquid phase method, and can be performed only by a dry method using a fine aerosol.
By the way, no matter how excellent the adhesion of the liquid fine aerosol after adhering is, if the aerosol fine particles floating in the gas do not adhere to the antibacterial material efficiently, there is no meaning.

Next, the adhesion mechanism of the nanometer-scale aerosol fine particles to the antibacterial material will be described.
If the size of the particles is reduced to the nanometer level, the behavior is considered to be close to water vapor and gas molecules. For example, in the warm room of the bathroom glass or in the winter or rainy season, the water vapor wall in the room is based on the temperature difference between the outside air and the room, similar to the condensation of water vapor on the wall in contact with the outside air. It is thought that movement and adhesion to the dominate. That is, the driving force and adhesion speed increase as the temperature difference between the adherend and the aerosol particles increases.

Unlike the wet method, the method using the gas phase micro aerosol which is one of the gist of the present invention is already at a relatively high temperature in the stage of heating and reaction of the metal compound during the production of the aerosol.
Therefore, the fine aerosol can be efficiently attached to the antibacterial material by effectively utilizing the high temperature state and utilizing this temperature difference without heating the antibacterial material. This is also a great feature that cannot be realized by the wet method.

An electrostatic force can be considered as a driving force for other adhesion mechanisms. Specifically, it is a method in which the aerosol fine particles and the base material are charged with opposite polarities and adhered using their electrostatic force.
In general, a polymer such as plastic is a substance that is very easily surface-charged. Therefore, taking advantage of this property is a very important factor for producing an excellent antibacterial material at low cost.
In processes involving flow and friction, such as plastics molding process and chemical fiber spinning process, the polymer is easily surface charged, and the polarity tendency of the charge has been clarified.
On the other hand, micro aerosol can be charged by passing it through a shower of negative or positive ions. Therefore, the adhesion of the micro aerosol to the antibacterial material can be greatly promoted by charging the micro aerosol with the opposite polarity to the antibacterial material.
This is also difficult in the wet method, and is a characteristic advantage of the dry method using a fine aerosol.
Here, when using the adhesion action based on electrostatic force, it is necessary to charge the fine aerosol, but when the particle diameter is several nanometers or less, from the relationship with the size of electrons or ions, It becomes difficult to charge the fine aerosol rapidly. For this reason, the lower limit of the fine aerosol particle size is preferably about 3 to 4 nanometers. Adhesion / deposition based on thermal (temperature difference) action is not limited to this, but its effect is smaller than that based on electrostatic force.

  As described above, silver and other metals with antibacterial and antifungal effects are converted into nanometer-order gas-phase / dispersed micro aerosols under atmospheric pressure, and the nanoparticle specificity of low-temperature liquefaction based on the miniaturization , And the method of applying and coating with high efficiency, low cost, and strong adhesion using thermal adhesion or electrostatic adhesion is an unprecedented method that takes advantage of the characteristics of gas phase microaerosol. The contribution to is great.

  According to the present invention, the following effects that cannot be obtained by the conventional method can be obtained.

(1) By making the antibacterial metal into a fine aerosol, the surface area is remarkably increased. As a result, the antibacterial effect is exhibited with a small amount of the antibacterial agent, the cost can be reduced, and it is particularly effective for expensive silver.
(2) By using an antibacterial metal as a gas phase micro aerosol, it is possible to develop nanoparticle specificity that is a significant melting point drop, and liquid adhesion is possible. Since the liquid adhesion is a planar adhesion, the low adhesion strength due to point adhesion, which has been a problem with solid particle adhesion, can be overcome, and the adhesion strength increases. As a result, it is possible to prevent the antibacterial agent from peeling off or dropping off from the antibacterial material due to wear or the like, and the antibacterial effect can be maintained for a long time.

(3) By using a vapor phase aerosol, an adhesion mechanism using electrostatic force with high adhesion efficiency can be employed, which is particularly effective for plastics that are likely to have surface charge. As a result, the generated aerosol can be used almost completely, and not only the cost can be reduced, but also the environmental load caused by the aerosol contained in the exhaust gas can be prevented.
(4) Since it is nanometer size, it becomes transparent to visible light. Therefore, it is effective for antibacterial / antifungal properties such as lenses and glasses that require visual transparency, or white fibers and clothing that require aesthetics.
(5) According to the present invention, silver, metal and other antibacterial / antifungal agents can be applied to fibers, plastics, ceramics, metals, etc. at low cost by a low environmental load treatment method that is efficient in a small amount without waste liquid treatment. In addition, it is possible to provide a method for firmly attaching and coating.

  EXAMPLES Next, although this invention is demonstrated concretely based on an Example, this invention is not limited at all by the following Examples.

<Manufacture of nanometer silver aerosol>
100 g of silver bulk material is heated to about 1000 degrees in an electric furnace under atmospheric pressure and nitrogen flow atmosphere (200 cc / min), and then mixed and cooled with cooling nitrogen gas (300 cc / min) to obtain about 100 Nanometer silver aerosol was obtained.

<Manufacture of nanometer silver aerosol>
In an atmospheric pressure / nitrogen gas flow (300 cc / min), 50 g of silver bulk material was placed on a resistance boat (made of an electric heating material), and electricity was applied to heat. By supplying about 200 watts of electricity, a silver aerosol of around 50 nanometers was obtained.

<Manufacture of nanometer silver aerosol>
In an atmospheric pressure / nitrogen gas flow (200 cc / min), a silver aerosol having a diameter of 0.3 mm was partially wound around a cantal resistance wire having a diameter of 0.5 mm, and a silver aerosol was obtained by energizing electricity. A fine particle silver aerosol of 10 nanometers or less was obtained with a power supply of 60 watts. Particle concentration was 10 ⁷ order per 1cc.
This method was the most efficient method for obtaining a fine silver aerosol. There is also an advantage that the particle diameter obtained can be easily changed by changing the amount of electricity supplied.

Here, although the manufacturing method of the nanometer silver aerosol was described, also in the case of copper, the nanometer copper aerosol was able to be manufactured by the method similar to the case of silver. However, the amount of electricity supplied required more in the case of copper than in the case of silver (about 100 watts).
In the case of copper, thermal decomposition of an organic compound of copper is more advantageous than the method of Example 3 from the viewpoint of energy consumption. For example, acetylated copper (copper acetylacetonate) is thermally decomposed in an electric furnace at 350 ° C. in a nitrogen gas flow (200 cc / min) to produce an aerosol having the same size as that of silver. did it. Here, since copper is more easily oxidized than silver, attention is required.
Since nanometer zinc aerosol has a low melting point of zinc (420 ° C), zinc aerosol of the same particle size can be easily obtained by a method similar to the method for producing nanometer silver aerosol with a small supply power of 20 watts or less. I was able to manufacture it. Here, attention is also required in the case of zinc because it is very easily oxidized and becomes zinc white (zinc oxide).
Thus, copper and zinc are more easily oxidized than silver and may adhere to the material to be treated as oxides, but these oxides also have antibacterial action. This is because, for example, a 10-yen copper coin whose surface is oxidized has an antibacterial action, a copper strainer is used to prevent slimming of kitchen sinks and drains, and ointments applied to the skin etc. It is understood from the fact that zinc white is added.

<Method of attaching and coating nanometer silver aerosol on organic polymer film>
The nanometer silver aerosol produced by the method of Example 3 is brought into contact with a polyvinyl formal film (softening point of about 100 ° C.) at a rate of 50 CC / min per unit surface area (1 cm 2) for about 10 minutes. Covered.
An electron micrograph of the silver adhesion / coating film thus obtained is shown in FIG. When the adhered aerosol particles in FIG. 1 are observed in detail, micro undulations of the underlying film are observed through the particles, which indicates that the aerosol particles are adhered in a liquid state.

<Test of antibacterial effect 1>
As the test bacterial solution, various bacteria were cultured, and a 1/500 dilution thereof was used.
The test sample was a film obtained by depositing and adhering in the same manner as in Example 4 except that the polyvinyl formal film (softening point of about 100 ° C.) was replaced with a polypropylene film (softening point of about 120 ° C.). It is. The 1 cm square section was placed in a medium petri dish to which the test bacterial solution was adhered, and the state after 24 hours of culture was observed. As a result, a halo that appeared to be a sterile area appeared around the film. From this, it can be seen that the test piece to which the fine silver aerosol adhered has an antibacterial effect.

<Inspection of antibacterial effect 2>
Since the antibacterial effect could be predicted by the antibacterial test 1, it was inspected in detail using the film adhesion method. As a result, when Escherichia coli (ATCC25922) was used, the test piece having an initial bacterial count of 5 × 10 ⁵ increased to 4 × ^{10 7} without treatment after 24 hours, whereas in the test piece with the same treatment as in Example 5, “detection” It was decreasing to "No". As a result, it was found that the antibacterial material treated by the method of the present invention has a significant antibacterial action.

<Influence of antibacterial treatment on transparency of treated material>
One of the features of this antibacterial treatment method is that the antibacterial treatment has little effect on the transparency of the treatment material. In order to inspect this feature, the change in the transmittance of the treatment material with the treatment time (measurement of the light transmittance at a wavelength of 500 nm with a spectrophotometer (U-2000 manufactured by Hitachi, Ltd.)) I investigated. As a test piece for the processing material, glass and an acrylic resin plate in which transparency is important are used. At the deposition time corresponding to Example 5, no decrease in the permeability was detected. Furthermore, in the electron microscope observation of the test piece after the 3 times adhesion time treatment, the aerosol was adhered to almost the entire surface, but no decrease in the transmittance was observed. It was a single particle layer with a particle adhesion layer thickness of several nanometers that did not show a decrease in transmittance despite being adhered to the entire surface, and a visible light wavelength (about 500 nm, 0.5 μm). ) Is considered to be sufficiently thin and transparent. When the deposition time was further increased, the permeability started to decrease after about 20 times and then decreased rapidly. The thickness of the adhered particle layer was measured and found to be about 300 nanometers. This value was found to correspond approximately to the visible light wavelength.
From the above results, it has been found that the method of the present invention is effective for antibacterial treatment of eyeglasses or the like that require transparency or materials that require aesthetics.

<Durability of washing and washing>
The adhesion strength of the metal antibacterial agent is also a feature of the present invention. That is, when the metal antibacterial agent is a nanometer-scale fine aerosol, the phenomenon of melting point lowering is induced, and the adhesion strength can be increased by adhering in a liquid metal state.
As an inspection method for adhesion strength, indirect but practical, changes in the number of washings and antibacterial effects based on Example 4 were examined. As a sample, a polyethylene film to which silver aerosol was adhered under the same conditions as in Example 4 was used. As the washing method, the change in antibacterial effect was examined by the same method as in Example 5 after stirring by a washing machine in the same manner as usual for 40 minutes per time.

As a result, the antibacterial effect did not change until the number of times of washing 10 times, but after that, the halo (sterile area) showing the antibacterial effect gradually decreased, and after 20 times of washing, the halo was not seen, and the antibacterial effect was I thought it was almost gone.
In the case of polymers such as plastics, the deposition / adhesion strength of the aerosol largely depends on the delicate relationship between the thermal characteristics and the aerosol atmosphere temperature. For example, by setting the aerosol temperature to be slightly higher than the melting point of the plastics, it is also predicted that the plastics partially melt at the time of adhesion and the adhesion strength increases. It is possible to further increase the adhesion strength by making such a device.

<Improvement of adhesion effect of micro aerosol by electrostatic force>
In the examples up to Example 7, the action based on the temperature difference between the aerosol and the base material using the heat at the time of generation is used as the adhesion / deposition action of the aerosol particles from the gas to the antibacterial material. . However, adhesion / deposition based on this acting force is not so effective. Especially in plastics, the temperature is limited to about 100 ° C. because of heat resistance. On the other hand, in the case of polymers such as plastics, static electricity tends to be generated due to friction and the like, and it is predicted that the use of electrostatic force is very effective for adhesion and deposition. However, it should be noted here that electrostatic force is not necessarily effective in increasing adhesion strength. It is only an effect on the adhesion / deposition rate of the generated fine aerosol.
The adhesion effect due to electrostatic force was inspected by the following method.
In general, plastics are easily negatively charged. Therefore, the aerosol must be positively charged. In this example, a polyethylene film was used as the plastic. On the other hand, the silver aerosol was positively charged by corona discharge (a high voltage (approx. 5 KV) was applied in an atmospheric gas).
The adhesion effect due to electrostatic force was evaluated by passing a positively charged silver aerosol-containing gas over a polyethylene film and measuring the particle concentration before and after passage.
The particle concentration was measured using a product of TSI, Inc., which is called a differential mobility analyzer (commonly called DMA (Differential Mobility Analyzer)).
In addition, in order to remove the effect of the thermophoretic force accompanying the heat generated during aerosol generation, a cooling gas was mixed to obtain a room temperature gas.

As a result of the inspection, the particle concentration of the generated silver aerosol was on the order of 10 ⁷ particles per cc. After particles charged by charging device is attached, deposited on polyethylene film, particle concentration after passage was 10 ^two orders per 1 cc. On the other hand, the concentration after passing without charging was on the order of 105 per cc.
From this, it has been clarified that the adhesion / deposition effect is greatly increased by performing the charging operation, although the adhesion / deposition occurs even when the aerosol is not charged.
That is, by using the electrostatic force generated by the charging operation, the generated fine aerosol is not wasted and effectively used as an antibacterial agent, and the non-adhered aerosol contained in the exhaust gas is greatly reduced. It has become clear that it is effective in reducing environmental impact.
Moreover, the adhesion strength of the silver particles to the polyethylene film could be increased by heat-treating the polyethylene film deposited and deposited by charging the aerosol.
Furthermore, the use of electrostatic force has the following advantages.
In only the heating method up to Example 7, only temperature is a control factor, and liquefaction and adhesion / deposition are based on its action. What is the optimum temperature for liquefaction and optimum temperature for adhesion action? , Not necessarily match. On the other hand, the electrostatic force is an action only as a deposition action, and is a factor independent of the thermal action required for liquefaction. Therefore, by controlling the temperature and electrostatic charge independently, It is possible to precisely control aerosol deposition and adhesion strength.

  As described in detail above, the present invention provides a metal, such as silver, having antibacterial and antifungal effects, as a gas phase / dispersed fine aerosol having a nanometer order size under atmospheric pressure, and is made of ceramics, plastics, metal According to the present invention, the surface area is significantly increased by making the antibacterial metal into a fine aerosol according to the present invention, and as a result, the antibacterial effect appears with a small amount of the antibacterial agent and the cost. Can be reduced. This is particularly effective for expensive silver. In addition, this makes it possible to develop nanoparticle specificity that is a significant melting point drop and enables liquid adhesion. Since the liquid adhesion is a planar adhesion, the low adhesion strength due to point adhesion, which has been a problem with solid particle adhesion, can be overcome, and the adhesion strength increases. As a result, it is possible to prevent the antibacterial agent from peeling off or dropping off from the antibacterial material due to wear or the like, and the antibacterial effect can be maintained for a long time.

Further, it is possible to employ an adhesion mechanism using electrostatic force having a large adhesion efficiency, which is particularly effective for plastics that are likely to have surface charge. As a result, the generated aerosol can be used almost completely, and not only the cost can be reduced, but also the environmental load caused by the aerosol contained in the exhaust gas can be prevented. Moreover, since it is nanometer size, it becomes transparent in visible optics. Therefore, it is effective for antibacterial and antifungal properties such as lenses and glasses that require visible optical transparency, or for white fabrics and fibers that require aesthetics.

As described above, according to the present invention, a metal-based antibacterial / antifungal agent such as silver can be applied to fibers, plastics, ceramics, metals, etc. by a low environmental load treatment method that is efficient in a small amount and does not have waste liquid treatment. It is possible to provide a method and a product for firmly attaching and coating at low cost.

  Further, according to the present invention, antibacterial / antifungal agents such as silver, which can prevent the antibacterial agent from peeling and dropping off from the antibacterial material due to wear and the like, and can maintain the antibacterial effect for a long period of time, and the antibacterial / antibacterial coated with it Antibacterial materials, articles having antibacterial / antifungal functions, and metallic, antibacterial / antifungal agents such as silver, with a low environmental impact treatment method that is efficient in a small amount without waste liquid treatment, fibers, plastics, ceramics Further, a method for firmly attaching and coating a metal or the like at low cost and a product thereof are provided.

It is an electron micrograph of nanometer scale dispersed silver aerosol particles adhering to the plastic surface.

Claims (13)

  A metal-based inorganic antibacterial and antifungal agent characterized by comprising an aerosol as an active ingredient, obtained by converting an antibacterial metal into a gas phase microaerosol.   The metal-based inorganic antibacterial and antifungal agent according to claim 1, wherein the metal or metal compound is vaporized and dispersed to form an aerosol under atmospheric pressure by heating or chemical reaction.   The metal inorganic antibacterial / antifungal agent according to claim 1 or 2, wherein the metal comprises one or more of silver, copper and zinc.   The metal-based inorganic antibacterial / antifungal agent according to claim 1 or 2, wherein the aerosol has an average particle size of 0.001 to 0.5 µm.   Under atmospheric pressure, a metal or a metal compound is made into an aerosol in which a metal is vapor-phase / dispersed by heating or chemical reaction, and the metal is attached to the material to be treated by contacting the aerosol with the material to be treated. Antibacterial and antifungal material characterized by being coated.   6. The antibacterial / antifungal material according to claim 5, wherein an aerosol heated to a temperature at which the material to be treated is not denatured and the material to be treated are brought into contact with each other.   6. The antibacterial / antifungal material according to claim 5, wherein the aerosol is charged and adhered to and coated on the material to be treated by electrostatic force with the material to be treated.   The metal-based inorganic antibacterial / antifungal material according to claim 5, wherein the aerosol has an average particle size of 0.001 to 0.5 μm.   Under atmospheric pressure, the metal or metal compound is heated or chemically reacted to form an aerosol in which the metal is in a gas phase / dispersion, and the antibacterial / antifungal metal is treated by bringing the aerosol into contact with the material to be treated. An antibacterial / antifungal metal adhesion / coating method characterized by adhering / coating to a material.   The method according to claim 9, wherein the material to be treated is brought into contact with the aerosol heated to a temperature at which the material to be treated does not change in quality.   The method according to claim 9, wherein the aerosol is charged and attached to and coated on the material to be processed by electrostatic force with the material to be processed.   The method according to claim 9, wherein the aerosol has an average particle size of 0.001 to 0.5 μm. An article provided with an antibacterial / antifungal function, comprising the antibacterial / antifungal material according to claim 5 as a constituent element.