JP3368338B2 - Antibacterial and antifungal ceramics and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an antibacterial and antifungal ceramics and a method for producing the same. Specifically, the present invention is not only water resistance, light resistance, heat resistance,
The present invention relates to a safe antibacterial / antifungal ceramic having excellent properties in terms of antibacterial / antifungal activity and durability of antibacterial / antifungal effect, and a method for producing the same.

[0002]

It has long been known that ions of silver, copper, zinc, and platinum have antibacterial and antifungal activity, but they are inconvenient to handle when they are used in the form of a solution, and the antibacterial and antifungal effect persists. There were also problems in terms of durability and safety. Recently, an inorganic antibacterial and antifungal agent has been developed in which these metal ions are carried on montmorillonite which is a zeolite or clay mineral and which overcomes the above-mentioned drawbacks (for example, Zenji Hagiwara,
Satoshi Ando, Zeolite, Vol.4, 1 (1987), Tatsuo Yamamoto, Masashi Uchida, Yasuo Kurihara, Journal of Antibacterial and Antifungal, Vol.19, 425 (199)
1), A. Oya, T. Banse, F. Ohashi, S. Otani, Appl. C
lay Sci., Vol.6, 135 (1991)).

However, the zeolite-based antibacterial and antifungal agent has a drawback that the antibacterial and antifungal agent has a small antibacterial and antifungal effect and the water resistance is poor because the metal ions are too strongly supported.
On the contrary, the montmorillonite antibacterial and antifungal agent has a weak metal ion carrying ability, so that the elution rate of the metal ions is high and the antibacterial and antifungal effect persists. In addition, since the silver ion concentration is 50 ppb or less, 100 ppb or less in Germany and 200 ppb or less in Switzerland according to the water quality standards in the United States, there is a safety problem with montmorillonite antibacterial and antifungal agents, and further discoloration during use There was a problem.

[0004]

In view of the above points, the present invention provides not only water resistance, heat resistance, light resistance, weather resistance, stability and safety, but also antibacterial and antifungal activity and sustained antibacterial and antifungal effects. It is an object of the present invention to provide an economical antibacterial and antifungal ceramics having excellent properties in terms of properties and a method for producing the same.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the present inventor has conducted extensive studies on an inorganic antibacterial and antifungal composition, and as a result, a substrate or a substrate coated with a conductive film or a conductive film The substrate of (1) is coated with a titanium oxide film containing at least one metal ion selected from silver, copper and zinc, or is further coated with a titanium oxide film or a platinum film if necessary. In addition to the action of metal ions, the antibacterial and antifungal ceramics produced by the method produces an electron or a hole in the titanium oxide film by receiving light from sunlight or an electric light to carry out redox, so that the solution or The present inventors have found that it is possible to effectively prevent the propagation of bacteria and mold on the membrane, and have completed the present invention.

That is, according to the present invention, at least one metal ion selected from silver, copper and zinc is obtained by firing a substrate or a substrate coated with a conductive film or a material coated on a conductive substrate. Of an antibacterial and antifungal ceramics characterized by coating a titanium oxide film containing a metal oxide on a substrate on which metal ions are not strongly supported, or further coating a titanium oxide film or a platinum film on it. A manufacturing method, a substrate having a binder layer or an adsorbent- free titania sol liquid containing at least one metal ion selected from silver, copper, and zinc, or a substrate having a conductive coating or a conductive substrate the method of producing an antibacterial antifungal ceramic, characterized in that it comprises a step of firing the coating onto the surface thereof if necessary Or baked coated with Taniazoru liquid, is a manufacturing method of antimicrobial and antifungal ceramic, characterized in that the platinum coated film.

The material of the substrate used in the present invention may be any material such as concrete, glass, plastic, ceramics or metal as long as it has the required strength. The substrate used in the present invention may be transparent or opaque, but the transparent substrate is convenient because light can pass through the substrate from the outside and enter.

The substrate coated with a conductive film used in the present invention is a substrate coated with copper or aluminum or a transparent conductive film such as tin oxide, ITO (indium tin oxide) or zinc oxide. There are things. As a method for coating the conductive film on the substrate, electrolytic plating method, CVD method, PV
D method, sputtering method, etc. are mentioned.

Examples of the conductive substrate used in the present invention include metals such as copper, aluminum and titanium, tin oxide glass and ITO (indium tin oxide) glass. Since tin oxide glass and ITO glass are colorless and transparent, light can be transmitted through the substrate from the outside and is convenient.

The substrate used in the present invention may have any shape such as a prismatic shape, a cylindrical shape, a spherical shape, a conical shape, a gourd shape, and a rugby ball shape. Further, the substrate may be in a closed form, may or may not have a lid, and may have a circular tubular shape or a rectangular tubular shape.

The metal ions used in the antibacterial and antifungal ceramics according to the present invention are silver, copper and zinc ions,
You may use 2 or more types of metal ions selected from these.

The titanium oxide film used in the present invention may be formed by heating and oxidizing a titanium film with a gas flame or the like, but a titania sol liquid is prepared from a titanium alkoxide obtained by a reaction between titanium tetrachloride and alcohol. , Dip coating method and spin coating method,
It is preferable that the substrate is coated by a coating method, a spray pyrolysis method, or the like, and then baked to manufacture. Alternatively, a suspension of ultrafine particles of titanium oxide may be coated on a substrate by a dip coating method, a spin coating method, a coating method, a spray method, or the like, and then baked to manufacture. At that time, in order to obtain a strong titanium oxide film strongly adhered to the substrate, it is necessary to reduce the concentration of the titania sol liquid and apply or spray or spin coat when the viscosity is low, or reduce the pulling speed of the substrate. Therefore, it is desirable that the thickness of the titanium oxide film be 0.1 to 0.3 μm. And the firing temperature at that time is 500 ° C to 550 ° C.
The degree is the most preferable. By repeating this work,
It is possible to obtain a thick and durable titanium oxide film.

The antibacterial and antifungal ceramics according to the present invention, in which a substrate is coated with a titanium oxide film containing at least one metal ion selected from silver, copper and zinc, is a titania sol liquid or ultrafine particles of titanium oxide. Silver in the suspension,
Add a metal salt solution containing at least one metal ion selected from copper and zinc or dissolve the metal salt,
It can be manufactured by coating on a substrate by a dip coating method, a spin coating method, a coating method, a spray pyrolysis method or the like, and then firing. At that time, the antibacterial and antifungal property is changed by changing the concentration of the metal salt solution, the amount of the metal salt, or the number of times the substrate is coated and baked by a dip coating method, a spin coating method, a coating method, a spray pyrolysis method, or the like. Silver contained in ceramics,
The metal ion concentration of copper and zinc can be changed. Examples of the metal salt used at this time include various salts such as sulfates, nitrates, carbonates, acetates, ammonium salts, halides such as chlorides and bromides, and organic salts such as stearates and acetates. , But not limited to these. Further, it may be an anhydrous salt or a hydrated salt or a mixture thereof, or a silver salt or a copper salt, a zinc salt,
It may be a mixture of platinum salts.

An antibacterial and antibacterial film obtained by coating a substrate with a titanium oxide film containing at least one metal ion selected from silver, copper and zinc according to the present invention, and further coating a titanium oxide film on the substrate, if necessary. Moldy ceramics are antibacterial and antifungal ceramics prepared by the above method, which are coated with a titanium oxide film containing at least one metal ion selected from silver, copper, and zinc on a substrate, a titania sol solution or It is manufactured by coating a suspension of fine particles of titanium oxide on a substrate by a dip coating method, a spin coating method, a coating method, a spray pyrolysis method, or the like, and then firing the coated material. At this time, the thickness of the titanium oxide film on the surface can be adjusted by changing the number of times the substrate is coated and baked by a dip coating method, a spin coating method, a coating method, a spray pyrolysis method, or the like.
This makes it possible to appropriately control the sustained release rate of silver, copper, and zinc metal ions and the effective period of antibacterial and antifungal ceramics, and to prevent the concentration of metal ions in water from exceeding the water quality standard. .

The concentration of metal ions used in the antibacterial and antifungal ceramics according to the present invention is 0.0001 to 10% by weight in the case of silver and 0.1% in the case of copper with respect to the titanium oxide film.
01-15% by weight, in the case of zinc 0.02-20% by weight
If it is less than this, the antibacterial and antifungal effect is weak, and if it is more than this, the amount of metal ions eluted increases. The optimal concentration of the metal ion in the antibacterial and antifungal ceramics can be determined depending on the period of use and the required degree of antibacterial and antifungal effect.

Further, as a method for coating the surface of the platinum film used in the present invention, if necessary, a photoelectric deposition method or a CVD method.
Method, PVD method, sputtering method and the like. By adjusting the thickness of the platinum film, the sustained release rate of silver, copper, and zinc metal ions and the efficacy of antibacterial and antifungal ceramics can be adjusted appropriately, and the concentration of metal ions in water conforms to the water quality standard. You can prevent it from being exceeded.

The antibacterial and antifungal ceramics according to the present invention thus obtained, in addition to the action of antibacterial and antifungal metal ions such as silver, produce electrons in the titanium oxide film upon receiving light such as sunlight or electric light. The redox action of the holes can effectively prevent the growth of bacteria and mold in the solution or on the film. Therefore, if you apply this to tiles etc. and stretch it inside the pool, you can prevent the bottom and walls of the pool from getting slimy and slippery, and if you apply it to the tiles of the bathroom and the outer wall of the building, It is possible to prevent darkening due to the above. Further, when applied to a container containing drinking water or the like, it is possible to prevent the propagation and spoilage of various bacteria and to store the drinking water or the like at room temperature for a long period of time. Further, when the substrate is a thin film, sheet or woven fabric, it can be used as clothes, medical supplies or packaging bags. In addition to the antibacterial ceramics according to the present invention, a drainboard, a bath tub, a bathtub,
Fountain tiles, sinks, triangular corners of sinks, handrails for pools and bathrooms, washbasins, cutting boards, washbasins, fish showcases, medical equipment, shoes, slippers, tanks for humidifiers, whiskers, carpets, etc. A wide range of applications are possible.

[0018]

EXAMPLES Among the examples of the present invention, particularly representative ones and reference examples are shown below.

Reference Example 1 0.1 mol of titanium isopropoxide was diluted with 100 ml of absolute ethanol, 2.7 ml of 2N hydrochloric acid was added with stirring to prepare a transparent sol solution, and the dip coating method was used. A titanium oxide film was coated on a slide glass substrate. That is, a slide glass substrate was immersed in this sol solution, pulled up, dried, and then baked at 400 ° C. After repeating this 20 times, it was baked at 550 ° C. to form a titanium oxide film of about 4 μm on the slide glass substrate. This was dipped in a 0.5 mol / l silver nitrate aqueous solution, pulled up, dried, and then dipped in the sol solution described above to further coat five titanium oxide films by the dip coating method. The antibacterial and antifungal effect of the obtained antibacterial and antifungal ceramics was examined by the following method. First, the bacteria collected from the food machine were cultivated in a meat extract broth medium for 24 hours, and 1 ml of the obtained bacterial solution was dropped on two points on the sample, and a membrane filter was placed on the sample. Three
Static culture was performed at 7 ° C. for 24 hours. Then, a phosphate buffer was added, and after shaking, 1 ml was taken out and the number of surviving bacteria was measured by the pour plate culture method. As a result, the number of surviving bacteria was almost 0, and a sterilization rate of 99.9% was obtained as compared with the blank test performed using only a slide glass.

Example 1 125 ml of titanium isopropoxide was added to 20 ml of isopropyl alcohol and then added dropwise to 750 ml of distilled water while stirring, and 5 g of silver nitrate and zinc nitrate hexahydrate 1 were added.
2 g, 6 ml of 70% nitric acid were added. 80 this solution
A transparent sol liquid was prepared by heating at 0 ° C. for 8 hours, and a titanium oxide film was coated on a tin oxide glass substrate by spin coating. First, a tin oxide glass substrate is used for 300 minutes per minute.
This sol solution was dropped while rotating at a speed of 0 rotation, dried, and then calcined at 400 ° C. After repeating this 20 times, it was baked at 550 ° C. to form a titanium oxide film of about 5 μm on the tin oxide glass substrate. This was placed in a 2 g / l aqueous solution of potassium chloroplatinate in ethanol, and while being stirred by a magnetic stirrer, the light of a 100 W mercury lamp was irradiated for 4 hours, and the surface of the titanium oxide film was coated with platinum by a photoelectric deposition method. . The antibacterial and antifungal effect of the obtained antibacterial and antifungal ceramics was examined by the following method. First, 1 ml of staphylococcal or E. coli broth cultivated in meat extract broth medium
Was dropped on two points on the sample, a membrane filter was placed on the sample, and static culture was performed at 37 ° C. for 24 hours.
Then, a phosphate buffer was added, and after shaking, 1 ml was taken out and the number of surviving bacteria was measured by the pour plate culture method. As a result, a sterilization rate of 99.2% for Staphylococcus or 94.2% for Escherichia coli was obtained as compared with the blank test performed using only tin oxide glass.

Example 2 125 ml of titanium isopropoxide was added to 20 ml of isopropyl alcohol and then added dropwise to 750 ml of distilled water while stirring, and 20 g of copper sulfate pentahydrate and 5 ml of 70% hydrochloric acid were added. This solution was heated at 80 ° C for 8 hours to prepare a transparent sol solution, which was applied to a metal washbasin with a brush, dried, and baked at 300 ° C. After repeating this 15 times, the transparent sol liquid prepared without adding copper sulfate was similarly repeated 5 times and fired at 500 ° C. The obtained basin was filled with water from a fishbowl and allowed to stand under a fluorescent lamp for one month. The surface did not become slimy, the water remained transparent, and no germs or algae were grown. When a metal washbasin not coated with a titanium oxide film was used, algae grew in one week, slimming occurred, and the water became cloudy.

Example 3 A colorless and transparent glass ball provided with a transparent conductive film of ITO was coated with a titanium oxide film containing copper sulfate in the same manner as in Example 2, and further coated with a titanium oxide film. 2 g / l
Was placed in an aqueous solution of potassium chloroplatinate in ethanol and stirred with a magnetic stirrer, and irradiated with light of a 100 W mercury lamp for 4 hours to coat the surface of the titanium oxide film with platinum by a photoelectric deposition method. Put the obtained spherical antibacterial antifungal ceramics in a transparent glass bottle containing natural fresh water,
I left it in a bright place for a month. As a result, when spherical antibacterial / antifungal ceramics was not added, the water became cloudy and miscellaneous bacteria propagated, but when spherical antibacterial / antifungal ceramics was added, the water remained transparent and almost no bacteria were present. Not detected.

Reference Example 2 125 ml of titanium isopropoxide was added to 20 ml of isopropyl alcohol and then added dropwise to 750 ml of distilled water while stirring, and 6 ml of 70% nitric acid was added.
This solution was heated at 80 ° C. for 8 hours to prepare a transparent sol solution, and 20 titanium oxide films were coated on white ceramic tiles by the dip coating method in the same manner as in Reference Example 1. This was immersed in an aqueous solution containing 200 g / l of zinc chloride and 5 g / l of potassium chloroplatinate and pulled up,
After drying, 6 layers of titanium oxide film were further coated by the dip coating method in the same manner as above. The obtained antibacterial and antifungal ceramic style was attached to the wall of the pond, and the pond was filled with water. I left it for two months as it was, but the tile did not get slimy.

Reference Example 3 A transparent sol solution prepared in the same manner as in Reference Example 1 was sprayed on a colorless and transparent glass ball having a diameter of 5 mm, and then dried.
It was baked at 50 ° C. This was repeated 20 times and baked at 500 ° C., then immersed in 100 ml of an aqueous solution containing 15 g of silver nitrate, 20 g of copper nitrate hexahydrate and 25 g of zinc nitrate hexahydrate, taken out and dried. This was further sprayed with a sol solution, dried, and baked at 350 ° C. This is repeated 5 times and baked at 500 ° C., then put in an aqueous ethanol solution of 2 g / l potassium chloroplatinate and stirred with a magnetic stirrer, while being irradiated with light of a 100 W mercury lamp for 4 hours, by a photoelectric deposition method. The surface of the titanium oxide film was coated with platinum. The antibacterial and antifungal effect of the obtained spherical antibacterial and antifungal ceramics was examined by the following method. First, miscellaneous bacteria collected from food machinery are statically cultivated in a meat extract broth medium for 24 hours, and 5 ml of the obtained bacterial solution is put in 70 ml of a phosphate buffer solution containing spherical antibacterial and antifungal ceramics, Shaking culture was performed. After 24 hours, 1 ml of the bacterial solution was taken out and the number of surviving bacteria was measured by the pour plate culture method. As a result, a sterilization rate of 97% was obtained as compared with the blank test performed using only glass beads. Further, when the light of an incandescent lamp was irradiated during the shaking culture, the sterilization rate was improved to 99%.

Example 4 After adding 400 g of isopropyl alcohol to 2.5 kg of titanium isopropoxide, it was added dropwise to 15 kg of distilled water while stirring, and 100 g of silver nitrate and 12% of 70% hydrochloric acid were added.
0 ml was added and heated at 80 ° C. for 24 hours. An alumina cutting board was dipped in the obtained transparent sol solution to prepare a reference example 1.
In the same manner as above, 15 layers of titanium oxide film were coated by the dip coating method. Then, five layers of titanium oxide film were similarly coated on the surface thereof with a transparent sol liquid prepared without adding silver nitrate, and baked at 500 ° C. The obtained antibacterial and antifungal cutting board was used for 2 months, but no growth of fungi or germs or discoloration was observed on its surface. Further, the obtained antibacterial and antifungal cutting board was immersed in water for 2 days, and the concentration of silver ions in the water was 10 ppb or less, which was below the water quality standard.

[0026]

As described above, the present invention provides water resistance,
Not only heat resistance, light resistance, weather resistance, stability, safety,
It is an object of the present invention to provide an economical antibacterial / antifungal ceramic having excellent properties in terms of antibacterial / antifungal activity and durability of antibacterial / antifungal effect, and a method for producing the same. A substrate or a substrate coated with a conductive film or a conductive substrate is coated with a titanium oxide film containing at least one metal ion selected from silver, copper and zinc. In addition to the action of metal ions, the antibacterial and antifungal ceramics generate electrons and holes in the titanium oxide film in response to light from sunlight or electric lights to carry out redox, and thereby in solution or on the film. Propagation of bacteria and mold can be effectively prevented. Therefore, if you apply this to tiles etc. and stretch it inside the pool, you can prevent the bottom and walls of the pool from becoming slimy and slippery,
When applied to bathroom tiles and building exterior walls, it is possible to prevent darkening due to mold, etc. In addition, if applied to a container containing drinking water, etc., it is possible to store the drinking water etc. for a long time at room temperature because it can prevent the propagation and spoilage of various bacteria, and when the substrate is a thin film or sheet, a woven fabric. It can also be used as clothing, medical supplies and packaging bags.
The titanium oxide used in the present invention is also used in paints, cosmetics, toothpaste, etc., and has the advantages of excellent weather resistance and durability, nontoxicity, and safety. Therefore, the antibacterial and antifungal ceramics according to the present invention are water resistant. Excellent in heat resistance, heat resistance, light resistance, weather resistance, stability and safety. In addition to the antibacterial and antifungal ceramics according to the present invention, a sludge and a bath tub,
Bathtubs, fountain tiles, sinks, triangular corners of sinks, basins for pools and bathrooms, washbasins, cutting boards, washbasins, fish showcases, medical equipment, shoes, slippers, humidifier tanks and outlet nozzles, Wide range of applications such as beard shaving and carpet.

Claims (3)

(57) [Claims] 1. A substrate having excellent antibacterial and antifungal properties by the action of one or more metal ions of silver, copper and zinc and the redox action of electrons and holes generated in a titanium oxide film upon receiving light. By baking the material coated above, silver, copper,
A method for producing an antibacterial and antifungal ceramics, comprising a titanium oxide film containing at least one metal ion selected from zinc and containing no binder layer, which is coated on a substrate on which metal ions are not strongly supported, wherein Antibacterial and antifungal properties, characterized by including a step of coating a titania sol liquid containing at least one metal ion selected from copper, zinc and zinc on a substrate having no binder layer or an adsorbent and firing the solution. Method of manufacturing ceramics. 2. A substrate coated with a conductive film or a conductive substrate is used as the substrate.
A method for producing the antibacterial and antifungal ceramics described. 3. A titanium oxide film having a thickness of 0.0001 to 1
0% by weight of silver or 0.01 to 15% by weight of copper, 0.0
The method for producing an antibacterial and antifungal ceramics according to claim 1 or 2, which contains 2 to 20% by weight of zinc.