JPH11278969A - Ceramic material having antibacterial mildewproofing property and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a ceramic material having antibacterial mildewproofing property and containing a polyfunctional material having photocatalytic function and an antibacterial metal in a state distributed in the surface part of a glazing layer of a ceramic material by a low-cost one-bake method. SOLUTION: A non-baked glaze 2 for ceramic is coated with a material having high melting point compared with the glaze, further coated with a polyfunctional material 3 having photocatalytic function and then coated with an aqueous solution of the ion of an antibacterial metal 5. The coated product is irradiated with ultraviolet rays to support the antibacterial metal on the polyfunctional material having photocatalytic function and the product is baked to obtain the objective product. As an alternative, the objective material is produced by coating the non-baked glaze with a material having a melting point higher than that of the glaze and mixed with a polyfunctional material 4 having photocatalytic function, further coating with an aqueous solution of an antibacterial metal ion, irradiating with ultraviolet rays to support the antibacterial metal 5 on the polyfunctional material having photocatalytic function and baking the product.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic product having antibacterial and antifungal properties and a method for producing the same, and more particularly to a technique for holding an antibacterial and antifungal material on the surface of a glaze layer serving as a function developing portion.

[0002]

2. Description of the Related Art Conventionally, TiO ₂ , Sn and the like have been used as photocatalyst materials which cause oxidation and reduction reactions when irradiated with ultraviolet rays.
O ₂ , ZnO, SrTiO ₃ , WO ₃ , Fe ₂ O _{3 and the} like are known, and examples of application to ceramic products and the like are seen. Ceramic products and the like to which these photocatalytic materials are applied exhibit antibacterial and antifungal properties. In addition, by using the reducing power of the photocatalyst to carry antibacterial metals such as Ag and Cu on the surface,
The antifungal performance can also be improved.

A method for forming the photocatalyst layer is to apply the sol of the photocatalyst material to a once-baked base material by spray coating or the like, and then perform heat treatment again to bake the photocatalyst material. Generally, the temperature is lower than the firing temperature. For example, PCT / JP9
4/02077. In this method for forming a photocatalyst layer, a baking step is added to one step, so that a cost increase by baking twice is a major problem.

In addition to the photocatalytic technology, there is a silver-based antibacterial technology for imparting antibacterial properties to ceramic products. In conventional silver-based antibacterial ceramic products, an antibacterial component is kneaded into the glaze or an aqueous solution or suspension of the antibacterial component is used. The suspension is applied to the glaze and then fired once to produce the product.Since the manufacturing process is simpler than photocatalytic porcelain products, the cost is low, but with the melting of the glaze in the firing process, antibacterial There is a problem that the components are more easily buried inside the glaze layer than at the surface of the glaze layer, and there is a problem that a desired antibacterial and antifungal effect cannot be obtained.

[0005]

Conventional antibacterial and antifungal porcelain products have the disadvantage that the photocatalyst system is expensive and the silver system does not have the desired antibacterial and antifungal power.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an antibacterial / antifungal porcelain product capable of exhibiting a desired antibacterial / antifungal property at a low cost by firing once. And a method for manufacturing the same.

[0007]

The object of the present invention is to fix a multifunctional material and an antibacterial metal uniformly on the glaze layer surface by firing once.
This can be achieved by distributing.

When the photocatalyst is baked by firing twice, both the multifunctional material and the antibacterial metal are uniformly fixed and distributed on the glaze layer surface. This is because in the second baking, since the baking is performed at a lower temperature than the first baking temperature, the glaze melts but has high viscosity, and the multifunctional material and the antibacterial metal are not buried. A common means of making the glaze highly viscous during the firing process is to make the glaze higher in melting point. It seems that if the melting point of the first glaze is increased by firing once, the problem of the multifunctional material and antibacterial metal buried inside the glaze layer can be solved, but replacing the ceramic glaze with a high melting glaze When the first layer is applied, the stress difference between the base material and the glaze generated during the firing process is remarkable, so that defects such as peeling of the glaze and cracks occur.

In the present invention, a multi-functional material and an antibacterial metal are not buried by reducing the stress difference between the base material and the glaze by providing a ceramic glaze on the first layer and a high melting point layer thereon.
The occurrence of defects is suppressed, and the desired antibacterial and antifungal properties can be exhibited.

As a multifunctional material having a photocatalytic function, Ti
O ₂ , SnO ₂ , ZnO, SrTiO ₃ , WO ₃ , Fe ₂ O ₃
And it may be a single type alone or a combination of two or more types. In actual use, there is a method of coating on glaze by spraying or the like, or mixing into glaze, so that the form may be any of powder, suspension and sol.

[0011] Antibacterial metals include Ag, Cu, Zn, N
It is selected from i, Mn, and Co, which may be used alone or in combination of two or more. In actual use, an aqueous solution which can be present in the form of metal ions is desirable since it is applied on a multifunctional material having a photocatalytic function by spraying or the like and then photoreduced by ultraviolet rays.

The method for producing an antibacterial and antifungal ceramic product according to the present invention comprises applying a material having a melting point higher than that of the glaze to a ceramic glaze before firing, applying a multifunctional material thereon, and applying the outermost layer. By reducing and fixing the antibacterial metal, and baking it, the multifunctional material having photocatalytic function and the antibacterial metal are distributed on the glaze layer surface without being buried from the glaze surface even if the glaze melts I did it.

In another method for producing an antibacterial and antifungal ceramic product according to the present invention, a ceramic glaze before firing is mixed with a multifunctional material having a higher melting point than the glaze and having a photocatalytic function. After coating, the antibacterial metal is reduced and fixed to the outermost layer and fired so that the multifunctional material and antibacterial metal are distributed on the glaze layer surface without being buried from the glaze surface during firing. I made it.

As the material having a high melting point, SiO ₂ or Al ₂ O ₃ alone or a mixture thereof can be used, and the form may be either a sol or a suspension in which powder is dispersed in water.

As another form of the high melting point material, the melting point of the ceramic glaze is 10 ° C. or more and 200 ° C.
Glazes having a high melting point in the following ranges can also be used.

[0016]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, FIG. 1 shows two embodiments of the present invention at the same time, and a multifunctional material having a photocatalytic function and an antibacterial metal are fixed on the outermost layer of a ceramic product glaze and fired on the ceramic glaze when firing. The method of manufacturing an antibacterial and antifungal porcelain product in which a material having a melting point higher than that of the glaze was applied to prevent the burying of the multifunctional material and the antibacterial metal from the glaze layer surface to the inside of the glaze layer was shown in the order of steps. FIG. FIG. 2 is an enlarged sectional view of a ceramic product obtained by the same method.

In this embodiment, as shown in FIG. 1 (a), a ceramic glaze layer 2 is applied to the surface of a ceramic product base 1 before firing by spraying or the like, and then FIG. 1 (b).
As shown in (1), a material having a higher melting point than the glaze is sprayed on the surface of the ceramic glaze layer 2 using a spray or the like. Next, as shown in FIG. 1C, a sol or a powder suspension of a multifunctional material having a photocatalytic function is sprayed thereon using a spray or the like. Further, as shown in FIG. 1 (d), an antibacterial metal ion aqueous solution is sprayed using a spray or the like, and then FIG.
As shown in (e), the antibacterial metal is firmly supported on the multifunctional material by irradiating ultraviolet rays and utilizing the photoreduction reaction of the multifunctional material. Then, calcination is performed in a porcelain firing furnace to obtain an antibacterial and antifungal porcelain product in which a multifunctional material having a photocatalytic function and an antibacterial metal are fixed to the glaze layer surface shown in FIG.

FIG. 3 shows another embodiment of the present invention, in which a multifunctional material having a photocatalytic function and an antibacterial metal are fixed to the outermost layer of a ceramic product glaze and fired when the ceramic glaze is applied. Applying a mixture of multifunctional materials with a glaze having a higher melting point than the glaze to prevent the burying of the multifunctional materials and antibacterial metal from the glaze layer surface into the interior of the glaze layer
It is the figure which showed the manufacturing method of the mold-proof ceramic product in order of process. FIG. 4 is an enlarged sectional view of the porcelain product obtained by the same method.

In this alternative embodiment, first, FIG.
As shown in FIG. 3A, a ceramic glaze layer 2 is applied to the surface of a ceramic product base 1 before firing by spraying or the like, and then FIG.
As shown in (b), a mixture of a multifunctional material having a photocatalytic function with a material having a higher melting point than the glaze is sprayed on the surface of the ceramic glaze layer 2 by using a spray or the like. Next, FIG.
As shown in FIG. 3C, an antibacterial metal ion aqueous solution is sprayed thereon using a spray or the like, and then irradiated with ultraviolet rays as shown in FIG. An antibacterial metal is firmly supported on the material. Then, firing is performed in a firing furnace for ceramics to obtain an antibacterial and antifungal ceramic product in which a multifunctional material having a photocatalytic function and an antibacterial metal are fixed to the glaze layer surface shown in FIG.

[0020]

EXAMPLES Specific examples will be described below. (Example 1) as a base material was glazed pottery for glaze sanitary ware dried green body, rutile TiO ₂ powder as a multifunctional material having a photocatalytic function, 10 mass as high material melting point than ceramics for glaze % SiO ₂ sol and 1% by mass
Silver was selected as an equivalent mixture of Al ₂ O ₃ sol and antibacterial metal. First, the material having a high melting point is applied by a spray gun on a base material glazed with a ceramic glaze, and then a slurry in which rutile-type TiO ₂ powder is dispersed by the same mass of water is applied by the same spray gun. Next, an aqueous solution of silver nitrate having a concentration of 3% by mass was applied by a spray gun,
Ultraviolet rays having an intensity of 0 μW / cm ² are irradiated for 10 minutes to firmly carry the silver on the rutile TiO ₂ . Next, firing was performed at 1200 ° C. in a tunnel kiln used for the production of sanitary ware to obtain desired antibacterial and antifungal sanitary ware.

(Example 2) As a base material, a sanitary ware dried base was glazed with a ceramic glaze, and as a multifunctional material having a photocatalytic function, rutile type TiO ₂ powder, a material having a melting point higher than that of the ceramic glaze. Is Al against ceramic glaze
Silver powder was selected as the antibacterial metal obtained by adding and mixing 10 wt% of ₂ O ₃ powder. First, the material having a high melting point is applied by a spray gun on a base material glazed with a ceramic glaze, and then a slurry in which rutile-type TiO ₂ powder is dispersed with the same mass of water is applied by the same spray gun. Next, an aqueous solution of silver nitrate having a concentration of 3% by mass was applied by a spray gun, and then an ultraviolet ray having an intensity of 1000 μW / cm ² was applied to 10%.
Irradiation for 7 minutes to allow silver to be firmly supported on the rutile TiO ₂ . Next, a tunnel kiln used for sanitary ware production 1
Baking was performed at 200 ° C. to obtain desired antibacterial and antifungal sanitary ware.

(Example 3) As a base material, a sanitary ware dried base was glazed with a ceramic glaze, and as a multifunctional material having a photocatalytic function, rutile-type TiO ₂ powder, a material having a higher melting point than the ceramic glaze. Is SiO ₂ —Al ₂ O ₃ —K ₂
20% by mass of the rutile-type TiO ₂ powder was added to the O-based glaze, and silver was selected as the antibacterial metal. First, the material having a high melting point is applied on a base material glazed with a glaze for ceramics using a spray gun, and then an aqueous solution of silver nitrate having a concentration of 3% by mass is applied using a spray gun.
Ultraviolet light having an intensity of 00 μW / cm ² is irradiated for 10 minutes, and silver is firmly supported on the rutile TiO ₂ existing on the surface and inside the material having a high melting point. Next, firing was performed at 1200 ° C. in a tunnel kiln used for the production of sanitary ware to obtain desired antibacterial and antifungal sanitary ware.

For evaluation of antibacterial activity, E. coli (Esc
herichia coli IFO 3972 strain). Place an aluminum frame in a sealed container lined with sterilized paper impregnated with 80 ml of sterilized distilled water, place antibacterial and antifungal sanitary ware which has been treated with ethanol for disinfection, and place in an incubator at 30 ° C. Let stand for ~ 2 hours. This sample was inoculated with 200 μl (about 400,000 CFU) of the prepared bacterial solution dropwise, and allowed to contact and stand in the dark for 8 hours. Next, the bacterial solution of the sample was wiped with a sterilizing gauze, collected in 10 ml of physiological saline, 1 ml of the solution was mixed with a normal agar medium, and cultured at 36 ° C. for 1 day to measure the viable cell count. In order to determine the mortality of the sample, the number of viable bacteria was measured at the same time using the fired surface of the glaze for ceramics as a comparative sample. The bacterial kill rate was determined from the difference in the number of viable bacteria between the comparative sample and the example, and this was used as an evaluation index.

Further, in order to compare the smoothness of the surface of the embodiment with the fired surface of the glaze for ceramics, a stylus type surface roughness meter (RANK) was used.
The average roughness Ra was determined using TAYLOR HOBSON S4C type), and this was used as an index for evaluation. Furthermore, in order to confirm the situation under actual use conditions, a toilet bowl was manufactured in each example, and the toilet was actually used without cleaning for three months. The comparison with the sanitary ware toilet using the glaze for ceramics was performed visually.

The results are summarized in FIG. The viable cell count after 8 hours in each example was significantly lower than the glaze for ceramics.
It shows good antibacterial properties. The surface roughness was not much different from the glaze for ceramics in each example, and it was found that sufficient smoothness was maintained. In detail, those coated with a multifunctional material having a photocatalytic function after applying a material having a higher melting point than the glaze for ceramics (Examples 1 and 2) have a slightly higher antibacterial effect, but conversely have a higher smoothness. Is slightly better when a multifunctional material having a photocatalytic function is mixed with a material having a higher melting point than a ceramic glaze (Example 3). In addition, as for the actual use status, it was confirmed that the yellowness of the water draft in the ball was slightly yellower in each of the examples than in the case of using the glaze for ceramics.

[0026]

According to the present invention, the following effects are exhibited by the above configuration. (1) After applying a material having a higher melting point than the glaze on the ceramic glaze, apply a multifunctional material having a photocatalytic function,
Since the antibacterial metal is supported and fired by utilizing the photocatalytic function of the multifunctional material, the multifunctional material and the antibacterial metal are not buried in the glaze layer from the glaze layer surface portion, and have high antibacterial and antifungal ability. Ceramic products having relatively low production costs. (2) After coating a glaze for ceramics with a material that has a higher melting point than the glaze and a mixture of multifunctional materials having a photocatalytic function, use the photocatalytic function of the multifunctional material to carry antibacterial metal. Because it is fired at the very least, multifunctional materials and antibacterial metals are not buried inside the glaze layer from the glaze layer surface, and ceramic products with antibacterial and antifungal ability and excellent smoothness have relatively low production costs. can get.

[0027]

[Brief description of the drawings]

FIG. 1 is a view showing a manufacturing process of an antibacterial and antifungal ceramic product according to the present invention in the order of steps.

FIG. 2 is an enlarged sectional view of a porcelain product obtained by the same method.

FIG. 3 is a view showing another manufacturing process of the antibacterial / antifungal ceramic product according to the present invention in the order of steps.

FIG. 4 is an enlarged sectional view of a ceramic product obtained by the same method.

FIG. 5 is a diagram showing the effect of each embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Ceramic product base material 2 ... Glaze layer for ceramics 3 ... Layer of the material whose melting point is higher than the glaze for ceramics 4 ... Multifunctional material having photocatalytic function 5 ... Antibacterial metal 6 ... Multifunctional material having photocatalytic function is mixed Layer of material with a higher melting point than glazed ceramic

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Katsuhiro Kawakami Inventor 2-1-1 Nakajima, Kokurakita-ku, Kitakyushu-shi, Fukuoka

Claims (9)

[Claims] 1. An antibacterial / antifungal ceramic product characterized in that a multifunctional material having a photocatalytic function and an antibacterial metal are distributed on the glaze layer surface. 2. The multi-functional material is made of TiO ₂ , SnO ₂ , Zn
_{O, SrTiO 3, WO 3,} Fe 1 selected from ₂ O ₃ alone or in combination antibacterial and antifungal ceramic product according to claim 1 by 3. The antibacterial metal is Ag, Cu, Zn, N
The antibacterial and antifungal porcelain product according to claim 1, which is one or a combination of two or more selected from i, Mn, and Co. 4. A material having a melting point higher than that of the glaze applied to the ceramic glaze before firing, followed by applying a multifunctional material having a photocatalytic function, and further applying an ionic aqueous solution of an antibacterial metal. An antibacterial and / or antibacterial agent, characterized in that the antibacterial metal is supported and fired using the photocatalytic function of the multifunctional material.
Method for producing anti-mold ceramic products 5. A method in which a mixture of a multifunctional material having a photocatalytic function with a material having a higher melting point than that of the glaze is applied on a ceramic glaze before firing, and then an ionic aqueous solution of an antibacterial metal is further applied thereon. A method for producing an antibacterial and antifungal porcelain product, characterized in that an antibacterial metal is supported and baked by utilizing the photocatalytic function of the multifunctional material. 6. The multi-functional material is made of TiO ₂ , SnO ₂ , Zn
O, SrTiO _3, WO _3, a method for manufacturing antibacterial and antifungal ceramic product according to Fe ₂ O ₃ 1 kind or claim 4 or claim 5 with two or more kinds selected from 7. The antibacterial metal is Ag, Cu, Zn, N
6. The method for producing an antibacterial / antifungal porcelain product according to claim 4 or 5, using one or a combination of two or more selected from i, Mn, and Co. 8. The high melting point material is SiO ₂ or A
l ₂ O ₃ alone or manufacturing method of antibacterial and antifungal ceramic product according to claim 4 or claim 5 which is a mixture, 9. The glaze according to claim 4, wherein the material having a high melting point is a glaze having a high melting point in the range of 10 ° C. to 200 ° C. with respect to the melting point of the ceramic glaze. Manufacturing method of antibacterial and antifungal ceramic products