JP2000169218A - Antimicrobial pottery and production thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antimicrobial pottery that shows excellent antimicrobial properties even when it is fired at elevated temperature, without deterioration in the material feel and colors by coating the ceramic raw materials with a mixture of an antimicrobial agent of magnesium metasilicate aluminate containing antimicrobial metal and a glaze, then heat-treating the coated ceramic. SOLUTION: After the ceramic base material is coated with a mixture of a glaze and an antimicrobial agent of an antimicrobial metal-containing magnesium metasilicate aluminate, the coated base material is heat-treated at 900-1,300 deg.C to give the objective antimicrobial ceramic product. In a preferred embodiment, this antimicrobial agent contains the antimicrobial metal in an amount of 0.01-40 wt.%, particularly magnesium metasilicate aluminate is substituted its ion-exchange capacity with metal ion in an amount of 10-90 mol%. The content of the antimicrobial agent included in the glaze is preferabl 0.1-30 wt.% Magnesium metasilicate aluminate shows high interaction with the microbial metal and resists the dissipation even in high-temperature firing and shows high antimicrobial activity and excellent duration.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antibacterial ceramic product and a method for producing the same, and more particularly, to a method for contaminating microorganisms such as bacteria by glazing a mixture of an antibacterial agent having high heat resistance and a glaze. The present invention relates to a clean and sanitary antibacterial ceramic product such as a ceramic product, an enamel product, and a glass product, which are excellent in antibacterial, antifungal, deodorant, and anti-slimming properties, and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, there has been a growing demand for cleansing of living environments, and antibacterial properties have been imparted to ceramic products such as daily necessities, building materials, tiles, ceramics, glass, and enamels that come into contact with human skin. Various proposals have been made on antibacterial ceramic products and their production methods.

For example, Japanese Patent Application Laid-Open No. Hei 5-201747 discloses a glaze characterized by containing hydroxyapatite carrying an antibacterial metal.
It is disclosed that the glaze is applied to an enamel product or a porcelain product and fired and melted. Also, Japanese Patent Application Laid-Open No. 8-333
No. 139 discloses that after providing an undercoat layer on the outer peripheral surface of a glass container, a coating layer comprising a top coat layer containing 0.2% or more of an antibacterial agent such as zeolite-silver is formed and baked. An antibacterial processed glass container is described.

However, the conventional antibacterial agent in which an antibacterial metal is supported on a hydroxyapatite or zeolite carrier has inferior heat resistance. When baked at a high temperature, the texture and color of the product change, and the crystal structure of the carrier is broken, so that the antibacterial effect is not sufficiently exhibited, and the durability is poor. Further, in the case of baking coating, there is a problem that durability is poor because the firing temperature is low.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems, and does not change the texture and color of ceramic products and shows high antibacterial performance even when fired at a high temperature of 1100 to 1300 ° C. It is an object of the present invention to provide an antibacterial ceramic product having excellent durability and a method for producing the same.

[0006]

The antibacterial ceramic product according to the present invention is characterized by containing an antibacterial agent comprising magnesium metasilicate aluminate containing an antibacterial metal. Further, the method for producing an antibacterial ceramic product according to the present invention comprises applying a mixture of an antibacterial agent and a glaze made of magnesium metasilicate aluminate containing an antibacterial metal to a ceramic substrate, and then heating the ceramic substrate. It is characterized by doing.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the antibacterial ceramic product according to the present invention will be described in detail below.

The antibacterial agent according to the present invention is composed of magnesium aluminate metasilicate containing an antibacterial metal (sometimes referred to as an antibacterial metal ion). It is insoluble in water, organic solvents, surfactants, etc., and is harmless to the human body. As the antibacterial metal, commonly known antibacterial metals such as silver, copper, zinc, and tin can be used. In particular, silver is a preferable metal in terms of high antibacterial properties and safety. The aforementioned antibacterial metal is supported on the base material by a known method. For example, metal components such as silver, copper, and zinc can be supported by an ion exchange method. The antibacterial agent in the present invention preferably contains an antibacterial metal in the range of 0.01 to 40% by weight, and particularly, 10 to 90 mol of the ion exchange capacity of magnesium aluminate metasilicate with antibacterial metal ions. % Is preferably ion-exchanged. Suitable antibacterial agents used in the present invention include the antibacterial compositions described in JP-A-3-275627.

In the present invention, the amount of the above-mentioned antibacterial agent contained in the glaze coating of the antibacterial ceramic product is desirably in the range of 0.1 to 30% by weight. When the content of the antibacterial agent is less than 0.1, the antibacterial property is not sufficiently exhibited,
On the other hand, when the content exceeds 30% by weight, the antibacterial metal ions become unstable, which may cause discoloration of the product or adversely affect the glaze coating. Particularly preferred content of the antibacterial agent is 0.5
In the range of 10 to 10% by weight.

In the method for producing an antibacterial ceramic product of the present invention, a mixture of the above-mentioned antibacterial agent and glaze is applied to a ceramic substrate (sometimes referred to as glaze), and then the ceramic substrate is heated.
As the glaze, a glaze usually used for ceramic products can be used, and the glaze applied to the ceramic base material employs a conventionally used glaze method, for example, a well-known method such as spraying, flowing, soaking. Is done.

In the method of the present invention, a mixture of an antibacterial agent composed of magnesium metasilicate aluminate containing an antibacterial metal and a glaze may be directly applied to the ceramic substrate, or the ceramic substrate may be applied to the ceramic substrate. After applying only the glaze, a mixture of the antimicrobial agent and the glaze described above may be further applied on the surface.

In the method of the present invention, the ceramic substrate coated with the mixture of the above-mentioned antibacterial agent and glaze can be heat-treated by a usual method. After the substrate is dried, the heat treatment is performed at, for example, 300 to 1400 ° C., preferably 90 ° C.
0 to 1300 ° C, more preferably 1100 to 1300 ° C
Baking in air at a temperature of Next, the fired product is cooled to obtain an antibacterial ceramic product (antibacterial ceramic product).

Since the antibacterial ceramic product of the present invention uses an antibacterial agent composed of magnesium metasilicate aluminate containing an antibacterial metal, it exhibits high antibacterial performance and excellent durability. Also does not change. Such an effect is considered to be due to the fact that magnesium metasilicate aluminate, which is a base material of the antibacterial agent, has a strong interaction with an antibacterial metal such as silver and is hardly scattered even when fired at a temperature of 1300 ° C. . Further, since the antibacterial agent is present in the glaze, it does not peel off from ceramic products.

The antibacterial ceramic products of the present invention include ceramic products, enamel products, glass products, and the like. For example, the ceramic products include tiles, bathtubs, toilets, hand washers, washbasins, tableware, vases, and the like. Insulation materials, bricks, tiles, etc. are exemplified.Examples of enamel products include tiles, bathtubs, toilets, hand washers, washbasins, dishes, etc., and glass products include dishes, such as cups, bowls, dishes, Examples include glass for building materials, vases, bottles, aquariums, and the like.

[0015]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

Production Example 1 4.9 g of silver nitrate (AgNO ₃ ) was dissolved in 5 liters of pure water, and the pH was adjusted to 5.0. This aqueous solution was added to magnesium aluminate metasilicate (Al ₂ O ₃ .MgO.2S)
iO ₂ · _{7H 2} O, an average particle diameter of 0.02 [mu] m, water content 20
(% By weight), the pH was adjusted again to 5.0, and the mixture was stirred at 60 ° C. for 1 hour. Then, it is washed with 5 equivalents of warm water, dried (110 ° C., 4 hours) and fired (600 ° C.).
C. for 2 hours) to obtain an antibacterial agent (A) containing 3.0% by weight of AgO.

Production Example 2 7.5 g of silver nitrate (AgNO ₃ ) was dissolved in 5 liters of pure water, and the pH was adjusted to 5.0. This aqueous solution was added to magnesium aluminate metasilicate (Al ₂ O ₃ .MgO.2S)
iO ₂ · _{7H 2} O, an average particle diameter of 0.02 [mu] m, water content 20
125% by weight), the pH was again adjusted to 5.0, and the mixture was stirred at 60 ° C for 1 hour. Then, it is washed with 5 equivalents of warm water, dried (110 ° C., 4 hours) and fired (600 ° C.).
C. for 2 hours) to obtain an antibacterial agent (B) containing 5.0% by weight of AgO.

Production Example 3 2.3 g of silver nitrate (AgNO ₃ ) was dissolved in 5 liters of pure water, and the pH was adjusted to 5.0. This aqueous solution was added to magnesium aluminate metasilicate (Al ₂ O ₃ .MgO.2S)
iO ₂ · _{7H 2} O, an average particle diameter of 0.02 [mu] m, water content 20
130% by weight), the pH was adjusted again to 5.0, and the mixture was stirred at 60 ° C for 1 hour. Then, it is washed with 5 equivalents of warm water, dried (110 ° C., 4 hours) and fired (600 ° C.).
C. for 2 hours) to obtain an antibacterial agent (C) containing 1.5% by weight of AgO.

Production Example 4 7.5 g of silver nitrate (AgNO ₃ ) was dissolved in 5 liters of pure water, and the pH was adjusted to 5.0. 100.5 g of hydroxyapatite (Ca ₁₀ (PO ₄ ) ₆ (OH) ₂ , average particle size 2 μm, water content 0.5% by weight) was added to this aqueous solution, and the pH was adjusted to 5.0 again, and the pH was adjusted to 60. Stirred at C for 1 hour. Then, it is washed with 5 equivalents of warm water and dried (110 ° C.,
4 hours) and firing (600 ° C., 2 hours)
Was obtained at 5.0% by weight.

Production Example 5 7.5 g of silver nitrate (AgNO ₃ ) was dissolved in 5 liters of pure water, and the pH was adjusted to 5.0. A-type zeolite (average particle size 2.0 μm, water content 23% by weight) 1
30 g was added, the pH was adjusted again to 5.0, and the mixture was stirred at 60 ° C. for 1 hour. Then, it is washed with 5 equivalents of warm water, dried (110 ° C., 4 hours) and fired (600 ° C., 2 hours)
Thus, an antimicrobial agent (E) containing 5.0% by weight of AgO was obtained.

Example 1 Samples of the antibacterial agents (A to E) obtained in Production Examples 1 to 5 were fired in an electric furnace at 1200 ° C. for 2 hours. The amount of silver oxide was measured for each of the fired samples (dissolved in acid and then measured by fermentation plasma analysis). Table 1 shows the results.
From Table 1, the amount of silver oxide reduced by high-temperature baking of an antibacterial agent using magnesium metasilicate aluminate as a base material is shown by antibacterial agents (D) and (E) using hydroxyapatite and A-type zeolite as a base material. It can be seen that the amount of reduction in silver oxide is smaller than that in Example 1.

[0022]

[Table 1]

Example 2 The antibacterial agent (A) obtained in Production Example 1 was mixed with a glaze so as to be 1% by weight, applied to the surface of an unglazed tile at a thickness of 50 μm, dried, and then dried at 500 ° C. for 1 hour. Firing, then 11
Baking at 40 ° C for 40 minutes, antibacterial tile sample (A-1)
I got Sample (A-1) had good color and no discoloration. The antibacterial tile sample (A-1) was rubbed 10 times with a bundle using a 30% aqueous solution of a detergent (manufactured by Kao: Homing Cleanser) and washed with water to prepare a sample (A-2).

Example 3 The antibacterial agent (B) obtained in Production Example 2 was used and treated in the same manner as in Example 2 to obtain an antibacterial tile sample (B-1). Sample (B-1) had good color and no discoloration. Also,
A washing operation was performed in the same manner as in Example 1 to obtain a sample (B-2).

Comparative Example 1 The antibacterial agent (D) obtained in Production Example 4 was used and treated in the same manner as in Example 1 to obtain an antibacterial tile sample (D-1). Further, a washing operation was performed in the same manner as in Example 1 to perform sample (D-2).
I got

Comparative Example 2 Using the antibacterial agent (E) obtained in Production Example 5, the same treatment as in Example 1 was performed to obtain an antibacterial tile sample (E-1). Further, a washing operation was performed in the same manner as in Example 1 to perform sample (E-2).
I got

Example 4 Evaluation of antibacterial tile samples The antibacterial tile samples obtained in Examples 1 and 2 and Comparative Examples 1 and 2 (unwashed) and the washed antibacterial tile samples were tested for antibacterial activity by the following method. Was done. Test sample: 5 × 5 cm Medium: meat extract, 10 mg / l + peptone, 20 mg /
l + sodium chloride, 10 mg / l Test bacteria: Escherichia coli, Staphylococcus aureus Measurement method: Inoculate 0.5 ml of the bacterial suspension on the test sample, cover with a covering film, cover at 35 ° C.
After 24 hours, the number of viable cells was measured, and the sterilization rate (%) was determined from Equation 1. Table 2 shows the results. The antibacterial tile of the present invention exhibits high antibacterial properties, and the antibacterial properties are reduced only by washing.

[0028]

[Equation 1] Bacteria reduction rate (%) = 100 × (initial viable cell count−viable cell count after 24 hours) / initial viable cell count

[0029]

[Table 2]

[0030]

The antibacterial ceramic product according to the present invention uses magnesium metasilicate aluminate as a base material of the antibacterial agent, and therefore has a strong interaction with the antibacterial metal, and is mixed with the glaze.
Even after high-temperature baking, there is little decrease in antibacterial metal, and a ceramic product exhibiting high antibacterial properties can be obtained.

Continued on the front page F term (reference) 4G030 AA07 AA30 AA36 AA37 AA61 BA32 GA33 GA35 4G031 AA03 AA24 AA29 AA30 AA39 BA26 GA16 GA18 4H011 AA02 BB18 BC18 BC20 DA01 DD07

Claims (2)

[Claims] 1. An antibacterial ceramic product comprising an antibacterial agent comprising magnesium aluminate metasilicate containing an antibacterial metal. 2. An antibacterial ceramic product, comprising: applying a mixture of an antibacterial agent comprising magnesium aluminate metasilicate containing an antibacterial metal and a glaze to a ceramic substrate, followed by heat treatment of the ceramic substrate. Manufacturing method.