TW201619302A - Antibacterial composition, antibacterial glaze composition, and antibacterial article - Google Patents

Abstract

The present invention provides an antibacterial composition, an antibacterial glaze composition, and an antibacterial article. The antibacterial composition of the present invention includes a mixture of silver powder and phosphate glass powder. The mass percentage of silver in the mixture containing silver powder accounts for 5% to 60%. The mass ratio of silver (A) to phosphate glass (P), i. e. A/P, is 0.05 to 1.5. The antibacterial composition in the present invention can improve the antibacterial performance and reduce the amount of the silver or that of silver compound in the composition.

Description

Antibacterial composition and antibacterial glaze composition and antibacterial article

The present invention relates to an antibacterial composition, an antibacterial glaze composition, and an antibacterial article. In particular, the present invention relates to a building material suitable for use in sanitary ware, medical supplies, enamel articles, various containers, tableware, and the like, ceramic tiles, and the like. Antibacterial composition having excellent antibacterial properties and various antibacterial glaze compositions containing the antibacterial composition and glaze, and various antibacterial glaze compositions using the various components of automobiles, panels of electrical equipment, and the like A film-forming antibacterial article is formed.

Currently, metals such as silver, copper, and zinc are widely used as antibacterial components. These metals are thought to have an effect of preventing bacterial proliferation by acting on their active enzymes in cells such as bacteria.

The concentration of the antibacterial component required to prevent the proliferation of the bacteria is expressed by the minimum inhibitory concentration (MIC). In general, in the case of the antibacterial component containing silver, for example, the MIC for Escherichia coli is about 200 ppm.

In order to impart antibacterial properties to ceramic or enamel articles, a method of using a glaze containing a metal or a metal oxide such as silver, silver oxide, copper, copper oxide, zinc, zinc oxide, or the like is known, and has been practically performed (for example). Refer to Patent Documents 1 to 3, etc.).

In order to impart good antibacterial properties to these ceramics or enamel articles, it is necessary to uniformly disperse an antibacterial metal or metal oxide such as silver in a glaze layer formed on the surface of a ceramic or enamel article, and to make these metals Or the metal oxide is dissolved on the surface of the ceramic or enamel article.

For example, as a method of efficiently dissolving silver ions on the surface of a ceramic or enamel product, a material obtained by coexisting a phosphoric acid component and a silver-containing compound is used for a ceramic or enamel glaze or the like (for example, Patent Document 4). CITATION LIST Patent Literature Patent Literature 1: Japanese Laid-Open Patent Publication No. Hei No. Hei. No. Hei. No. Hei. Bulletin 001380

Problems to be solved by the invention

In the case of forming a glaze layer using a glaze containing silver or a silver compound as an antibacterial agent, in order to visualize the antibacterial property by silver or a silver compound, for example, for Escherichia coli, it is necessary to make the glaze layer The silver concentration in the surface is from about 50 ppm to about 200 ppm (minimum inhibitory concentration (MIC)). In order to make the silver concentration in the surface of the glaze layer within this range, it is reasonable to add a silver or silver compound in an amount of from about 0.01% by mass to about 0.02% by mass in terms of silver based on the total amount of the glaze. However, in actuality, the amount of silver contained in the glaze layer is significantly reduced by the amount of silver contained in the glaze layer due to evaporation of the silver component or diffusion of the silver component to the base of the ceramic. Therefore, in order for the glaze layer to exhibit a predetermined antibacterial property, it is necessary to mix silver considerably with respect to the glaze, and therefore, there is a problem that the cost increases.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an antibacterial composition, an antibacterial glaze composition, and an antibacterial article which can improve antibacterial properties even when a small amount of silver or a silver compound is used in comparison with the prior art.

Method for solving the problem

In order to solve the above problems, the present inventors have conducted intensive studies and found that the content of the silver-containing powder in the mixture of the silver-containing powder and the phosphate glass powder is 5% by mass or more and 60% in terms of silver. When the mass ratio of the silver (A) and the phosphate glass (P) contained in the mixture, that is, the A/P ratio of 0.05 or more and 1.5 or less, is added to the antibacterial composition, In the antibacterial glaze composition, a small amount of silver or a silver compound is used as compared with the prior art, and the antibacterial property is better than ever, and the present invention has been completed.

In other words, the antibacterial composition of the present invention contains a silver-containing powder and a phosphate glass powder, and the content of the silver-containing powder in the mixture is 5% by mass or more and 60% by mass in terms of silver. Hereinafter, the mass ratio of silver (A) to phosphate glass (P) contained in the above mixture, that is, A/P is 0.05 or more and 1.5 or less.

The antibacterial glaze composition of the present invention, which comprises the antibacterial composition of the present invention and the glaze, wherein the content of the antibacterial composition is 0.01% by mass or more and 3 parts by mass in terms of silver relative to the glaze. %the following.

The antibacterial article of the present invention is characterized in that a film is formed by using the antibacterial glaze composition of the present invention.

Effect of the invention

In the antibacterial composition of the present invention, the content of the silver-containing powder in the mixture of the silver-containing powder and the phosphate glass powder is 5% by mass or more and 60% by mass or less in terms of silver, and the mixture contains Since the mass ratio of silver (A) to phosphate glass (P), that is, A/P is 0.05 or more and 1.5 or less, the antibacterial property can be improved and the content of silver or a silver compound can be reduced.

According to the antibacterial glaze composition of the present invention, the antibacterial composition and the glaze of the present invention are contained, and the content of the antibacterial composition is 0.01% by mass or more and 3% by mass or less in terms of silver with respect to the glaze. Therefore, the antibacterial property of the antibacterial glaze composition can be improved, and the content of silver or silver compound can be reduced.

According to the antibacterial article of the present invention, since the film is formed by the antibacterial glaze composition of the present invention, the antibacterial property of the surface of the antibacterial article can be improved, and the content of silver or a silver compound can be reduced.

Embodiments of the antibacterial composition, the antibacterial glaze composition, and the antibacterial article of the present invention will be described.

It is to be noted that the present invention is specifically described in order to better understand the gist of the invention, and is not intended to limit the invention unless otherwise specified.

[Antibacterial composition]

The antibacterial composition of the present embodiment contains a mixture of a silver-containing powder and a phosphate glass powder, and the content of the silver-containing powder in the mixture is 5% by mass or more and 60% by mass or less in terms of silver, in the above mixture. The mass ratio of silver (A) to phosphate glass (P), that is, A/P is 0.05 or more and 1.5 or less.

In the antibacterial composition of the present embodiment, the content of the silver-containing powder in the mixture of the silver-containing powder and the phosphate glass powder is 5% by mass or more and 60% by mass or less, preferably 10% by mass in terms of silver. % or more and 40% by mass or less.

When the content of the silver-containing powder in the mixture of the silver-containing powder and the phosphate glass powder is less than 5% by mass in terms of silver, the film formed by using the antimicrobial glaze composition containing the antimicrobial composition is used ( The glaze layer exhibits good antibacterial properties, and the amount of the antibacterial composition added to the antibacterial glaze composition is increased, which may affect the original film quality such as strength, gloss, and color. On the other hand, when the content of the silver-containing powder in the mixture of the silver-containing powder and the phosphate glass powder is more than 60% by mass in terms of silver, the content of the phosphate glass powder in the antibacterial composition is reduced. According to the relationship between the mass ratio of silver and phosphate glass to be described later, when the antibacterial glaze composition containing the antibacterial composition is applied to the surface of a ceramic or enamel product, it is not possible to suppress evaporation by evaporation. / diffusion results in a good effect of silver loss.

In the antibacterial composition of the present embodiment, the mass ratio of silver (A) to phosphate glass (P) contained in the mixture of the silver-containing powder and the phosphate glass powder is A/P of 0.05 or more and 1.5 or less. It is preferably 0.15 or more and 1 or less.

When the mass ratio of silver (A) to phosphate glass (P) contained in the mixture of the silver-containing powder and the phosphate glass powder is A/P less than 0.05, the absolute amount of silver contained in the antimicrobial composition is small. Therefore, in order to exhibit good antibacterial properties of the film formed by the antibacterial glaze composition containing the antibacterial composition, the amount of the antibacterial composition added to the antibacterial glaze composition is increased, and the antibacterial glaze is increased. The amount of phosphate glass contained in the composition is increased. In addition, the phosphate glass has a tendency to separate in the glaze containing cerium oxide (SiO ₂ ) as a main component and to float on the surface, and therefore, the phosphate contained in the antimicrobial glaze composition When the amount of the glass is too large, there is a possibility that the appearance of the glaze layer is whitened or the like, or the smoothness of the surface of the glaze layer is adversely affected. On the other hand, when the mass ratio of silver (A) to phosphate glass (P) contained in the mixture of the silver-containing powder and the phosphate glass powder is A/P exceeding 1.5, silver which cannot be bonded to the phosphate glass Since the ion (Ag+) is increased, the effect of suppressing the loss of silver caused by evaporation/diffusion is changed during the baking process after the antimicrobial glaze composition containing the antimicrobial composition is applied to the surface of the ceramic or enamel article. Not enough.

Next, the silver-containing powder and the phosphate glass powder which are components of the antibacterial composition of the present embodiment will be described.

"silver-containing powder"

The silver-containing powder is preferably a powder containing at least one selected from the group consisting of silver, silver phosphate, silver oxide, silver carbonate, silver nitrate, silver chloride, silver sulfide, and silver acetate, and more preferably contains silver, a powder of at least one of the group consisting of silver phosphate and silver oxide.

The BET specific surface area of the silver-containing powder is preferably 0.2 m ² /g or more, more preferably 0.3 m ² /g or more, still more preferably 0.4 m ² /g or more and 2.5 m ² /g or less.

The antibacterial composition of the present embodiment contains a silver-containing powder having a BET specific surface area of 0.2 m ² /g or more, and easily forms a secondary aggregate of the silver-containing powder and the phosphate glass powder. During the calcination of the object or the antibacterial glaze composition, the probability of interaction (bonding/phase separation) of the silver ions with the phosphate glass is increased. As a result, the effect of suppressing the loss of silver by evaporation and diffusion, and the effect of localization of silver ions on the surface of the coating film by the phase separation of the phosphate glass are improved, and the film containing the antimicrobial glaze composition is coated. It can exhibit excellent antibacterial properties.

On the other hand, when the BET specific surface area of the silver-containing powder is less than 0.2 m ² /g, it is difficult to form secondary aggregates of the silver-containing powder and the phosphate glass powder, and it is easy to become brittle even if secondary aggregates are formed. damage. Therefore, in the preparation of the antibacterial glaze composition, the silver-containing powder and the phosphate glass powder are separately present in the glaze, and silver ions and phosphoric acid are used in the baking of the antibacterial composition or the antibacterial glaze composition. It is difficult to bond the salt glass, and the effect of suppressing the diffusion and evaporation of silver is insufficient.

Here, the secondary aggregate refers to particles (secondary particles) in a state in which at least one primary particle containing silver powder interacts with primary particles of at least one phosphate glass powder by electrostatic interaction, Van der Waals A state in which a non-covalent bond interaction such as a force meets; or a state in which the interface is fixed due to the collision between the particles due to the collision between the particles, so that the interface is fixed and the particles are glued together.

The index of the size of the secondary aggregates includes the average particle diameter of the antimicrobial composition. The average particle diameter (median diameter) of the antimicrobial composition of the present embodiment measured by a laser diffraction/scattering measurement method is preferably 50 μm or less, more preferably 1 μm or more and 20 μm or less.

Further, the size of the secondary aggregates can also be directly observed by a scanning electron microscope (SEM) or the like. The longest width of the secondary aggregate is preferably 100 μm or less, more preferably 50 μm or less. It should be noted that the longest width of the secondary aggregate is the width from the one end of the secondary aggregate (indefinite shape) to the other end in the longest direction.

In the antibacterial composition, when the average particle diameter (median diameter) of the secondary aggregate exceeds 50 μm, or the longest width of the secondary aggregate exceeds 100 μm, the coarse secondary aggregate increases, and the antibacterial glaze is included. When the coating film of the composition is fired to form a film comprising the antimicrobial glaze composition, the size of the phase separation of the phosphate glass rich in silver ions is increased, and the phase separation in the antimicrobial glaze composition Since the number is reduced, the distribution of silver ions in the surface of the film containing the antimicrobial glaze composition becomes uneven, and the film may not have stable antibacterial properties.

"Phosphate glass powder"

In the phosphate glass powder, the oxide-converted component by the fluorescent X-ray measurement method preferably contains phosphorus pentoxide (P ₂ O ₅ ), aluminum oxide (Al ₂ O ₃ ), and sodium oxide selected from the group consisting of phosphorus oxide. At least any one of (Na ₂ O) and potassium oxide (K ₂ O).

In the phosphate glass powder, the content of P ₂ O _{5 which} is an oxide-converted component by the fluorescent X-ray measurement method is 25% by mass or more and 60% by mass or less, preferably 30% by mass or more and 50% by mass. the following.

When the content of P ₂ O ₅ is less than 25% by mass, the amount of silver ions bonded to the phosphate glass is reduced, and the effect of suppressing diffusion and evaporation of silver is insufficient. On the other hand, when the content of P ₂ O ₅ exceeds 60% by mass, when an antibacterial article is formed by forming a film on the surface of a ceramic or enamel product using an antibacterial glaze composition containing an antibacterial composition, Since the film is easily separated from the antimicrobial article, there is a possibility that the appearance and smoothness of the antimicrobial article are adversely affected.

In the phosphate glass powder, the content of Al ₂ O _{3 which} is an oxide-converted component by the fluorescent X-ray measurement method is 10% by mass or more and 35% by mass or less, preferably 20% by mass or more and 30% by mass or less. the following.

The phosphate glass powder forms a three-dimensional network structure by bonding of P ₂ O ₅ and Al ₂ O ₃ . It is soluble in water because it forms a linear condensed phosphate only when P ₂ O ₅ . Therefore, in the phosphate glass powder, when the content of Al ₂ O ₃ is less than 10% by mass, the linear condensed phosphate is increased, and therefore, an antibacterial glaze composition containing the antibacterial composition is used in a ceramic or enamel. When an antibacterial article is formed by forming a film on the surface of the product, the water resistance of the antibacterial article is deteriorated, and when it is used in an environment of water, silver is eluted from the film, and it may be difficult to exhibit long-lasting antibacterial properties. . On the other hand, when the content of Al ₂ O ₃ exceeds 35% by mass, the decrease in the solubility of the phosphate glass during the baking and the precipitation of Al ₂ O ₃ give a decrease in the antibacterial property and a smoothness of the surface of the glaze layer. Come to influence.

In the phosphate glass powder, the content of at least one selected from the group consisting of Na ₂ O and K ₂ O as an oxide-converted component by the fluorescent X-ray measurement method, that is, the combination of Na ₂ O and K ₂ O The total content is 10% by mass or more and 35% by mass or less, preferably 18% by mass or more and 28% by mass or less.

When the content of Na ₂ O and K ₂ O is less than 10% by mass, silver ions are not replaced by sodium ions (Na+) and potassium ions (K+) contained in the phosphate glass powder in a sufficient amount, and therefore, with phosphate glass The amount of bonded silver ions is reduced, and the effect of suppressing diffusion and evaporation of silver is insufficient. On the other hand, when the content of Na ₂ O and K ₂ O exceeds 35% by mass, in the case of preparing an antibacterial glaze composition, the amount of elution of the alkaline component increases, which affects the viscosity of the antibacterial glaze composition. It may have an adverse effect on the coating properties.

In the secondary aggregate of the silver-containing powder and the phosphate glass powder, the average primary particle diameter of the phosphate glass powder is preferably 20 μm or less, more preferably 5 μm or less.

When the average primary particle diameter of the phosphate glass powder exceeds 20 μm, it is difficult to form secondary aggregates of the silver-containing powder and the phosphate glass powder, and even if secondary aggregates are formed, they are likely to become brittle and break. Therefore, in the preparation of the antibacterial glaze composition, the silver-containing powder and the phosphate glass powder are separately present in the glaze, and silver ions and phosphoric acid are used in the baking of the antibacterial composition or the antibacterial glaze composition. It is difficult to bond the salt glass, and the effect of suppressing the diffusion and evaporation of silver is insufficient.

In the antibacterial composition of the present embodiment, it is preferred that the phosphate glass powder has a softening point lower than the melting point of the silver-containing powder. In the case where the softening point of the phosphate glass powder is higher than the melting point of the silver-containing powder, in the process of baking the antibacterial composition or the antibacterial glaze composition, the first melted silver is softened until the phosphate glass is softened. It is bonded to phosphate glass and therefore loses due to evaporation and diffusion.

In addition to the silver-containing powder and the phosphate glass powder, the antibacterial composition of the present embodiment may contain a glass powder, a mineral powder, a metal oxide, a metal salt compound, or the like, in order to adjust the meltability at the time of baking, and the like. Phosphate and the like.

[Method for Producing Antibacterial Composition]

The method for producing an antibacterial composition of the present embodiment is a method of mixing a phosphate glass powder with a silver-containing powder, and a method for producing a phosphate glass powder can be applied to a glass powder (frenched glass) which is usually performed. Manufacturing method, etc.

The mixing method of the silver-containing powder and the phosphate glass powder is not particularly limited, and is a large amount of secondary aggregates which form a silver-containing powder and a phosphate glass powder, and preferably generate moderate impact energy between the particles during mixing. A mixing method in which the collision frequency between the particles is high is preferably a mixing method in which a strong impact force and shear force do not occur. When strong impact and shear forces act, secondary aggregates formed from silver-containing powders and phosphate glass powders may be destroyed. Further, in the mixing method in which the mixing time is long and the high friction heat occurs, the secondary aggregates may become coarse and coarse, which is not preferable.

Examples of such a mixing method include a container-type rotary mixer such as a conical mixer, a mixing impeller type mixer such as a ribbon mixer, and a fluidized bed type mixer.

In the mixing of the silver-containing powder and the phosphate glass powder using the above mixing method, the mixing time is preferably 1 hour or more and less than 100 hours.

When the mixing time is short, the mixed state may become uneven. On the other hand, when the mixing time is long, coarse aggregates are generated, and the distribution of silver ions on the surface of the glaze layer becomes uneven, and the antibacterial property may become unstable.

The content of the silver-containing powder in the above-mentioned mixture is 5% by mass or more and 60% by mass or less in terms of silver, and the silver contained in the mixture is obtained by the above-mentioned mixture of the silver-containing powder and the phosphate glass powder. A) An antibacterial composition having a mass ratio of phosphate glass (P), that is, A/P of 0.05 or more and 1.5 or less, and an average particle diameter of 50 μm or less.

[Antibacterial glaze composition]

The antibacterial glaze composition of the present embodiment is an antibacterial glaze composition obtained by containing the above-described antibacterial composition and glaze of the present embodiment, and the content of the antibacterial composition is preferably in terms of silver relative to the glaze. It is 0.01% by mass or more and 3% by mass or less, and more preferably 0.05% by mass or more and 1.5% by mass or less.

Here, the reason why the content of the antibacterial composition is 0.01% by mass or more and 3% by mass or less in terms of silver in terms of silver is that the content of the antibacterial composition is less than 0.01% by mass in terms of silver, and the antibacterial property is obtained. When the amount of silver contained in the composition is too small, the antibacterial property is lowered, and as a result, the desired antibacterial property cannot be exhibited, and the antibacterial property of the antibacterial composition is lowered, which is not preferable. On the other hand, when the content of the antibacterial composition is more than 3% by mass in terms of silver, silver is contained to exhibit a desired antibacterial property or more, and most of the silver is wasted, which is not preferable.

In addition to the antibacterial composition and the glaze of the present embodiment described above, the antibacterial glaze composition of the present embodiment may further contain an auxiliary agent such as an inorganic powder such as a glass powder or a mineral powder, a thickener or a dispersant.

In the antibacterial glaze composition of the present embodiment, the antibacterial composition of the present embodiment is contained in an amount of 0.01% by mass or more and 3% by mass or less in terms of silver, in terms of silver, and the antibacterial property can be imparted to the glaze. Reduce the content of silver or silver compounds.

Therefore, a coating film is formed by applying the antibacterial glaze composition of the present embodiment to a ceramic article or an enamel article, and the coating film is heat-treated, thereby forming a coating film (glaze layer), which is capable of facing the ceramic article. Or enamel products impart antibacterial properties.

The coating film thickness (thickness of the coating film) of the antimicrobial glaze composition of the present embodiment with respect to the ceramic product or the enamel product is preferably 10 μm or more and less than 1000 μm. When the coating film thickness of the antimicrobial glaze composition is less than 10 μm, it is difficult to uniformly form a coating film containing the antimicrobial glaze composition on the surface of the ceramic product or the enamel product, which may cause unevenness in the appearance of the antimicrobial property. On the other hand, when the coating film thickness of the antibacterial glaze composition is 1000 μm or more, the amount of the antibacterial glaze composition used is increased, so that the cost is increased and economically unsatisfactory.

[antibacterial items]

The antibacterial article of the present embodiment is an article in which a film (glaze layer) is formed by the antibacterial glaze composition of the present embodiment, and as such articles, it is possible to prevent the washing of the bathroom, the toilet, the kitchen, the bathroom, and the like. Items used for contamination by bacteria or hospitals, food processing facilities, public facilities, etc., which need to protect life from bacteria, such as sanitary wares, containers, tableware, ceramic tiles, pottery and other ceramic products, containers, panels Enamel products such as cookware, electrical products, building materials and components.

By using the antibacterial glaze composition of the present embodiment to form a film on at least a necessary portion of the surface of the ceramic article or the enamel product, the antibacterial property of the surface of the article can be improved, and the content of silver or a silver compound can be reduced.

The film formed on the surface of the ceramic product or the enamel product may be a single layer or two or more layers, but a film formed by the antimicrobial glaze composition of the present embodiment is preferably used as the outermost layer. When the coating film formed using the antimicrobial glaze composition of the present embodiment is not used as the outermost layer, silver ions are less likely to be present on the surface of the coating film, and it may be difficult to exhibit antibacterial properties by silver.

As described above, the antibacterial composition of the present embodiment contains a mixture of a silver-containing powder and a phosphate glass powder, and the content of the silver-containing powder in the mixture is 5% by mass or more in terms of silver. In addition, the mass ratio of silver (A) to phosphate glass (P) contained in the above mixture, that is, A/P is 0.05 or more and 1.5 or less, so that the antibacterial property can be improved and silver or silver can be reduced. The content of the compound.

When an antibacterial composition comprising the above mixture of the silver-containing powder and the above phosphate glass powder is added to the glaze for calcination, silver ions and monovalent cations in the phosphate glass (for example, Na+) during calcination K+) is substituted, and silver ions are bonded to the phosphate glass. Therefore, it is possible to suppress the loss of silver due to evaporation of the silver component or diffusion of the silver component into the base (green body) of the ceramic. That is, in order to bond with a phosphate glass, a silver ion needs to be substituted with a monovalent cation in a phosphate glass. A divalent or higher cation (for example, Ca2+) is difficult to replace with silver ions because it strongly binds to phosphate glass. Therefore, in the antibacterial composition of the present embodiment, it is preferred that the phosphate glass powder contains a certain amount or more of monovalent cations such as Na+ and K+.

The antibacterial composition of the present embodiment is capable of suppressing the loss of silver due to evaporation or diffusion of the silver component as described above, and also because the phosphate glass is contained in the glaze containing ceria as a main component. When the silver is coated with silver and the phase separation occurs, and the phosphate glass has a large coefficient of thermal expansion and a light specific gravity at the time of firing, it is easy to localize in the vicinity of the surface of the coating film containing the antimicrobial glaze composition, and the coating can be made. The amount of silver on the surface increases. Thereby, even if the amount of addition of silver or a silver compound to the antimicrobial composition is reduced, the antimicrobial composition can exhibit antibacterial properties.

In order to fully exert the above effects, the mixing ratio of the silver-containing powder and the phosphate glass powder is important. In the antibacterial composition, in the case where the content of the silver-containing powder is larger than that of the phosphate glass powder, silver is bonded to the phosphate glass to suppress silver caused by evaporation or diffusion of the silver component. The effect of the loss becomes insufficient. On the other hand, in the antibacterial composition, when the content of the silver-containing powder is less than that of the phosphate glass powder, the content of silver in the antibacterial composition is small, so that the antibacterial composition and the glaze are contained. The antibacterial glaze composition of the material exhibits antibacterial properties, and it is necessary to add a large amount of the antibacterial agent to the antibacterial glaze composition, and the concentration of the phosphate glass in the antibacterial glaze composition is increased. As described above, the phosphate glass is phase-separated in the glaze containing ceria as a main component, and has a tendency to be localized on the surface of the film containing the antibacterial glaze composition, and therefore, the antibacterial glaze combination When the content of the phosphate glass in the material is large, appearance defects such as whitening of the film containing the antimicrobial glaze composition may occur, or the smoothness of the surface of the film may be adversely affected.

Further, phosphate glass has a tendency to cause phase separation in a glaze containing ceria as a main component, and silver ions are concentrated in the phase separation. Further, since the phosphate glass has a large thermal expansion coefficient and a light specific gravity at a high temperature, the phosphate glass after concentration of silver ions in the phase separation tends to float on the surface of the glaze layer. As a result, the amount of silver ions on the surface of the glaze layer increases.

Due to the above effects, the antibacterial composition of the present embodiment can exhibit excellent antibacterial properties with a smaller amount of silver or a silver compound than conventional ones.

Since the condensed phosphate (polymer of phosphoric acid) is ligand-bonded to the metal ion, it can be used as a trapping agent for metal ions such as a water treatment agent. The condensed phosphate does not have water resistance, but the phosphate glass containing alumina in the structure forms a three-dimensional network structure. In addition, aluminum enters the network structure of the phosphate glass, whereby the phosphate glass maintains the charge to be neutral, and therefore, the double bond of the phosphate glass is opened, and the structure of the phosphate glass is densified, and therefore, the embodiment is The water resistance of the antibacterial composition is improved.

The antibacterial composition of the present embodiment is suitable for use in sanitary ware or enamel products, and therefore, water resistance is an important point. Therefore, the phosphate glass in the antibacterial composition of the present embodiment needs to contain aluminum in the structure.

Further, in the antibacterial composition of the present embodiment, the silver-containing powder and the phosphate glass powder form a secondary aggregate, and the silver-containing powder and the phosphate glass powder are adjacent to each other, whereby the antibacterial glaze is present. During the firing of the composition, the probability of silver ions bonding to the phosphate glass is increased.

In the antibacterial glaze composition of the present embodiment, the antibacterial composition and the glaze of the present embodiment are contained, and the content of the antibacterial composition is 0.01% by mass or more and 3 times in terms of silver with respect to the glaze. Since the mass% or less is low, the antibacterial property of the antibacterial glaze composition can be improved, and the content of silver or a silver compound can be reduced.

According to the antibacterial article of the present embodiment, since the film is formed by the antibacterial glaze composition of the present embodiment, the antibacterial property of the surface of the antibacterial article can be improved, and the content of silver or a silver compound can be reduced.

Example

Hereinafter, the present invention will be more specifically described by way of examples and comparative examples, but the present invention is not limited to the following examples.

[Example 1]

"Production of antibacterial composition"

35 parts by mass of silver having a BET specific surface area of 0.6 m ² /g as a silver-containing powder and 65 parts by mass of phosphate glass powder A as a component shown in Table 1 were placed in a container rotary mixer, and mixed. Three hours, the antibacterial composition of Example 1 composed of a mixture of silver-containing powder and phosphate glass powder A was obtained.

"Measurement of average particle size"

The antibacterial composition was suspended in water, and the average particle diameter (median diameter) of the antibacterial composition was measured using a laser diffraction/scattering particle size distribution meter (trade name: LA-920, manufactured by Horiba, Ltd.).

The evaluation results are shown in Table 2.

"Confirmation of secondary aggregates"

The antibacterial composition was observed by a scanning electron microscope (SEM) to confirm the presence or absence of secondary aggregates.

Further, the longest width (μm) of the secondary aggregates was measured by a scanning electron microscope (SEM).

The evaluation results are shown in Table 2. Further, a scanning electron microscope (SEM) image of the antimicrobial composition is shown in Fig. 1 . The reflected electron composition (COMPO) image of the antimicrobial composition is shown in Fig. 2 . It should be noted that the scanning electron microscope image makes the shape of the measured object clear. Further, the reflected electron composition image is obtained by performing image processing on the reflected electron image, and the brightness of the image is different depending on the component of the measured object, and the atomic number is larger and brighter.

In Fig. 1, particles having a small particle diameter and forming a spherical shape are silver-containing powders, and particles having a large particle diameter and not forming a spherical shape are phosphate glass powder A. In Fig. 2, the bright (white) particles are silver-containing powders, and the dark (black) particles are phosphate glass powder A.

"Production of antibacterial glaze composition"

As the glaze raw material, a glaze raw material having the following composition was used.

SiO ₂ : 60% by mass

Al ₂ O ₃ : 13% by mass

CO _2: 10% by mass

CaO: 11% by mass

ZnO: 1% by mass

K ₂ O: 3 mass%

Na ₂ O: 2% by mass

60 parts by mass of this glaze raw material and 40 parts by mass of water were put into a ball mill, and after pulverizing for 15 hours, the antibacterial composition was added in an amount of 0.30% by mass relative to the glaze raw material in terms of silver, and further mixed for 1 hour. The antibacterial glaze composition of Example 1.

"The production of antibacterial ceramic plates"

A ceramic plate having a length of 50 mm, a width of 50 mm, and a thickness of 5 mm was prepared, and the antibacterial glaze composition was sprayed on the ceramic plate at a coating amount of 1000 g/m ² , and after drying, it was baked at a temperature of 1200 ° C for 1 hour. The antimicrobial ceramic plate of Example 1 was obtained.

"Antibacterial evaluation of antibacterial ceramic plates"

In order to confirm the water resistance, the above-mentioned antibacterial ceramic plate was immersed in water at 50 ° C for 16 hours. Then, the antibacterial property of the antibacterial ceramic plate was evaluated by Japanese Industrial Standard JIS Z 2801 "Antibacterial processed product - antibacterial test method and antibacterial effect", and the antibacterial activity value was determined by the following calculation formula.

Antibacterial activity value (R)=(Ut-U0)-(At-U0)=Ut-At

U0: the average value of the number of viable cells immediately after inoculation of the unprocessed test piece (pieces)

Ut: average value of viable cells after 24 hours of unprocessed test piece

At: the average value of the number of viable cells after 24 hours of the antibacterial processing test piece

Here, Escherichia coli and Staphylococcus aureus were tested to evaluate the antibacterial properties of the two bacteria. The evaluation was carried out in accordance with Japanese Industrial Standard JIS Z 2801 "Antibacterial processed products - Antibacterial test method and antibacterial effect", and when the antibacterial activity values of both Escherichia coli and Staphylococcus aureus were 2.0 or more, it was evaluated as qualified, and Escherichia coli and When the antibacterial activity value of either or both of S. aureus was less than 2.0, it was evaluated as unacceptable.

The evaluation results are shown in Table 2.

"Appearance evaluation of antibacterial ceramic plates"

The appearance of the obtained antibacterial ceramic plate was observed by visual inspection of a ceramic plate which was baked after the application of the glaze containing no antibacterial composition, and the presence or absence of discoloration, unevenness, foreign matter precipitation, bubbles, and the like was observed. A case where the appearance is unfavorable is unsatisfactory.

The evaluation results are shown in Table 2.

[Embodiment 2]

The antibacterial composition of Example 2 was produced in the same manner as in Example 1 except that the mixing ratio of silver to phosphate glass powder A was 25 parts by mass of silver and 75 parts by mass of phosphate glass powder A.

The antibacterial composition of Example 2 was measured in the same manner as in Example 1 to measure the average particle diameter and the secondary aggregate. The evaluation results are shown in Table 2.

Further, in the same manner as in Example 1, the antibacterial glaze composition of Example 2 and the antimicrobial ceramic plate were produced.

The antibacterial property of the antibacterial ceramic plate of Example 2 was evaluated in the same manner as in Example 1 to evaluate the antibacterial property and the appearance. The evaluation results are shown in Table 2.

[Example 3]

The antibacterial composition of Example 3 was produced in the same manner as in Example 1 except that the mixing ratio of silver to phosphate glass powder A was 15 parts by mass of silver and 85 parts by mass of phosphate glass powder A.

The antibacterial composition of Example 3 was measured in the same manner as in Example 1 to measure the average particle diameter and the secondary aggregate. The evaluation results are shown in Table 2.

Further, in the same manner as in Example 1, the antibacterial glaze composition of Example 3 and the antibacterial ceramic plate were produced.

The antibacterial ceramic plate of Example 3 was subjected to the same procedure as in Example 1 to evaluate the antibacterial property and the appearance. The evaluation results are shown in Table 2.

[Example 4]

The antibacterial composition of Example 4 was produced in the same manner as in Example 1 except that the mixing ratio of silver to phosphate glass powder A was 45 parts by mass of silver and 55 parts by mass of phosphate glass powder A.

The antibacterial composition of Example 4 was measured in the same manner as in Example 1 to measure the average particle diameter and the secondary aggregate. The evaluation results are shown in Table 2.

Further, in the same manner as in Example 1, the antibacterial glaze composition of Example 4 and the antibacterial ceramic plate were produced.

The antibacterial ceramic plate of Example 4 was subjected to the same procedure as in Example 1 to evaluate the antibacterial property and the appearance. The evaluation results are shown in Table 2.

[Example 5]

An antibacterial composition of Example 5 was produced in the same manner as in Example 1 except that silver having a BET specific surface area of 0.3 m ² /g was used as the silver-containing powder.

The antibacterial composition of Example 5 was measured in the same manner as in Example 1 to measure the average particle diameter and the secondary aggregate. The evaluation results are shown in Table 2.

Further, in the same manner as in Example 1, the antibacterial glaze composition of Example 5 and the antibacterial ceramic plate were produced.

The antibacterial ceramic plate of Example 5 was subjected to the same procedure as in Example 1 to evaluate the antibacterial property and the appearance. The evaluation results are shown in Table 2.

[Embodiment 6]

An antibacterial composition of Example 6 was produced in the same manner as in Example 1 except that silver phosphate having a BET specific surface area of 2.0 m ² /g was used as the silver-containing powder.

The antibacterial composition of Example 6 was measured in the same manner as in Example 1 to measure the average particle diameter and the secondary aggregate. The evaluation results are shown in Table 2.

Further, in the same manner as in Example 1, the antibacterial glaze composition of Example 6 and the antibacterial ceramic plate were produced.

The antibacterial ceramic plate of Example 6 was subjected to the same procedure as in Example 1 to evaluate the antibacterial property and the appearance. The evaluation results are shown in Table 2.

[Embodiment 7]

The antibacterial composition of Example 7 was produced in the same manner as in Example 1 except that silver oxide having a BET specific surface area of 1.5 m ² /g was used as the silver-containing powder.

The antibacterial composition of Example 7 was measured in the same manner as in Example 1 to measure the average particle diameter and the secondary aggregate. The evaluation results are shown in Table 2.

Further, in the same manner as in Example 1, the antimicrobial glaze composition of Example 7 and the antimicrobial ceramic plate were produced.

In the antibacterial ceramic plate of Example 7, the antibacterial property evaluation and the appearance evaluation were performed in the same manner as in Example 1. The evaluation results are shown in Table 2.

[Embodiment 8]

The antibacterial composition of Example 8 was produced in the same manner as in Example 1 except that the phosphate glass powder B of the component shown in Table 1 was used instead of the phosphate glass powder A.

The antibacterial composition of Example 8 was measured in the same manner as in Example 1 to measure the average particle diameter and the secondary aggregate. The evaluation results are shown in Table 2.

Further, in the same manner as in Example 1, the antibacterial glaze composition of Example 8 and the antibacterial ceramic plate were produced.

The antibacterial ceramic plate of Example 8 was subjected to the same procedure as in Example 1 to evaluate the antibacterial property and the appearance. The evaluation results are shown in Table 2.

[Embodiment 9]

The antibacterial composition of Example 9 was produced in the same manner as in Example 1 except that the phosphate glass powder C of the component shown in Table 1 was used instead of the phosphate glass powder A.

The antibacterial composition of Example 9 was measured in the same manner as in Example 1 to measure the average particle diameter and the secondary aggregate. The evaluation results are shown in Table 2.

Further, in the same manner as in Example 1, the antibacterial glaze composition of Example 9 and the antimicrobial ceramic plate were produced.

In the same manner as in Example 1, the antibacterial ceramic plate of Example 9 was subjected to antibacterial evaluation and appearance evaluation. The evaluation results are shown in Table 2.

[Embodiment 10]

The antibacterial composition of Example 10 was produced in the same manner as in Example 1 except that the mixing ratio of silver to phosphate glass powder A was 60 parts by mass of silver and 40 parts by mass of phosphate glass powder A.

The antibacterial composition of Example 10 was measured in the same manner as in Example 1 to measure the average particle diameter and the secondary aggregate. The evaluation results are shown in Table 2.

In addition, the antibacterial glaze composition of Example 10 and the antibacterial ceramic plate were produced in the same manner as in Example 1 except that the antibacterial composition was added in an amount of 2.5% by mass based on the glaze material in terms of silver. .

The antibacterial ceramic plate of Example 10 was subjected to the same procedure as in Example 1 to evaluate the antibacterial property and the appearance. The evaluation results are shown in Table 2.

[Example 11]

The antibacterial composition of Example 11 was produced in the same manner as in Example 1 except that the mixing ratio of silver to phosphate glass powder A was 5 parts by mass of silver and 95 parts by mass of phosphate glass powder A.

The antibacterial composition of Example 11 was measured in the same manner as in Example 1 to measure the average particle diameter and the secondary aggregate. The evaluation results are shown in Table 2.

In addition, the antibacterial glaze composition of Example 11 and the antibacterial ceramic plate were produced in the same manner as in Example 1 except that the antibacterial composition was added in an amount of 0.05% by mass based on the glaze raw material in terms of silver. .

The antibacterial ceramic plate of Example 11 was subjected to the same procedure as in Example 1 to evaluate the antibacterial property and the appearance. The evaluation results are shown in Table 2.

[Comparative Example 1]

The antibacterial composition of Comparative Example 1 was produced in the same manner as in Example 1 except that the mixing ratio of silver to phosphate glass powder A was 3 parts by mass of silver and 97 parts by mass of phosphate glass powder A.

In the antibacterial composition of Comparative Example 1, the measurement of the average particle diameter and the confirmation of the secondary aggregate were carried out in the same manner as in Example 1. The evaluation results are shown in Table 3.

Further, in the same manner as in Example 1, an antibacterial glaze composition of Comparative Example 1 and an antibacterial ceramic plate were produced.

In the antibacterial ceramic plate of Comparative Example 1, the antibacterial property evaluation and the appearance evaluation were carried out in the same manner as in Example 1. The evaluation results are shown in Table 3.

[Comparative Example 2]

The antibacterial composition of Comparative Example 2 was produced in the same manner as in Example 1 except that the mixing ratio of silver to phosphate glass powder A was 70 parts by mass of silver and 30 parts by mass of phosphate glass powder A.

The antibacterial composition of Comparative Example 2 was measured in the same manner as in Example 1 to measure the average particle diameter and the secondary aggregate. The evaluation results are shown in Table 3.

Further, in the same manner as in Example 1, the antibacterial glaze composition of Comparative Example 2 and the antibacterial ceramic plate were produced.

In the antibacterial ceramic plate of Comparative Example 2, the antibacterial property evaluation and the appearance evaluation were carried out in the same manner as in Example 1. The evaluation results are shown in Table 3.

[Comparative Example 3]

An antibacterial composition of Comparative Example 3 was produced in the same manner as in Example 1 except that the phosphate glass powder D of the component shown in Table 1 was used instead of the phosphate glass powder A.

In the antibacterial composition of Comparative Example 3, the measurement of the average particle diameter and the confirmation of the secondary aggregate were carried out in the same manner as in Example 1. The evaluation results are shown in Table 3.

Further, in the same manner as in Example 1, the antimicrobial glaze composition of Comparative Example 3 and the antimicrobial ceramic plate were produced.

In the antibacterial ceramic plate of Comparative Example 3, the antibacterial property evaluation and the appearance evaluation were carried out in the same manner as in Example 1. The evaluation results are shown in Table 3.

[Comparative Example 4]

The antibacterial composition of Comparative Example 4 was produced in the same manner as in Example 1 except that the phosphate glass powder E of the component shown in Table 1 was used instead of the phosphate glass powder A.

In the antibacterial composition of Comparative Example 4, the measurement of the average particle diameter and the confirmation of the secondary aggregate were carried out in the same manner as in Example 1. The evaluation results are shown in Table 3.

Further, in the same manner as in Example 1, an antibacterial glaze composition of Comparative Example 4 and an antibacterial ceramic plate were produced.

In the antibacterial ceramic plate of Comparative Example 4, the antibacterial property evaluation and the appearance evaluation were carried out in the same manner as in Example 1. The evaluation results are shown in Table 3.

[Comparative Example 5]

The antibacterial composition of Comparative Example 4 was produced in the same manner as in Example 1 except that the phosphate glass powder F of the component shown in Table 1 was used instead of the phosphate glass powder A.

In the antibacterial composition of Comparative Example 5, the measurement of the average particle diameter and the confirmation of the secondary aggregate were carried out in the same manner as in Example 1. The evaluation results are shown in Table 3.

Further, in the same manner as in Example 1, an antibacterial glaze composition of Comparative Example 5 and an antibacterial ceramic plate were produced.

In the antibacterial ceramic plate of Comparative Example 5, the antibacterial property evaluation and the appearance evaluation were carried out in the same manner as in Example 1. The evaluation results are shown in Table 3.

[Comparative Example 6]

The antibacterial composition of Comparative Example 6 was produced in the same manner as in Example 1 except that the mixing ratio of silver to phosphate glass powder A was 5 parts by mass of silver and 95 parts by mass of phosphate glass powder A.

In the antibacterial composition of Comparative Example 6, the measurement of the average particle diameter and the confirmation of the secondary aggregate were carried out in the same manner as in Example 1. The evaluation results are shown in Table 3.

In addition, the antibacterial glaze composition of Comparative Example 6 and the antibacterial ceramic plate were produced in the same manner as in Example 1 except that the antibacterial composition was added in an amount of 0.005 mass% based on the glaze material in terms of silver. .

In the antibacterial ceramic plate of Comparative Example 6, the antibacterial property evaluation and the appearance evaluation were carried out in the same manner as in Example 1. The evaluation results are shown in Table 3.

[Comparative Example 7]

The antibacterial composition of Comparative Example 7 was produced in the same manner as in Example 1 except that the mixing ratio of silver to phosphate glass powder A was 60 parts by mass of silver and 40 parts by mass of phosphate glass powder A.

In the antibacterial composition of Comparative Example 7, the measurement of the average particle diameter and the confirmation of the secondary aggregate were carried out in the same manner as in Example 1. The evaluation results are shown in Table 3.

In addition, the antibacterial glaze composition of Comparative Example 7 and the antibacterial ceramic plate were produced in the same manner as in Example 1 except that the antibacterial composition was added in an amount of 6% by mass based on the glaze raw material in terms of silver. .

In the antibacterial ceramic plate of Comparative Example 7, the antibacterial property evaluation and the appearance evaluation were carried out in the same manner as in Example 1. The evaluation results are shown in Table 3.

[Comparative Example 8]

An antibacterial composition of Comparative Example 8 was produced in the same manner as in Example 1 except that silver having a BET specific surface area of 0.1 m ² /g was used as the silver-containing powder.

In the antibacterial composition of Comparative Example 8, the measurement of the average particle diameter and the confirmation of the secondary aggregate were carried out in the same manner as in Example 1. The evaluation results are shown in Table 3.

Further, in the same manner as in Example 1, an antibacterial glaze composition of Comparative Example 8 and an antibacterial ceramic plate were produced.

In the antibacterial ceramic plate of Comparative Example 8, the antibacterial property evaluation and the appearance evaluation were carried out in the same manner as in Example 1. The evaluation results are shown in Table 3.

[Comparative Example 9]

The antibacterial composition of Comparative Example 9 was produced in the same manner as in Example 1 except that the mixing time of the silver-containing powder and the phosphate glass powder A in the production of the antibacterial composition was 100 hours.

The antibacterial composition of Comparative Example 9 was measured in the same manner as in Example 1 to measure the average particle diameter and the secondary aggregate. The evaluation results are shown in Table 3.

Further, in the same manner as in Example 1, an antibacterial glaze composition of Comparative Example 9 and an antibacterial ceramic plate were produced.

In the antibacterial ceramic plate of Comparative Example 9, the antibacterial property evaluation and the appearance evaluation were carried out in the same manner as in Example 1. The evaluation results are shown in Table 3.

Table 1

Table 2

table 3

As is clear from the results of Table 2, the antibacterial ceramic plates of Examples 1 to 11 had no appearance defects. Further, it was found that the antibacterial ceramic plates of Examples 1 to 11 were excellent in antibacterial performance.

On the other hand, in Comparative Example 1, the silver content in the antibacterial composition was 3% by mass, and the mass ratio (A/P) of silver to phosphate glass was 0.031. Therefore, the antimicrobial ceramic plate was whitened, and the appearance was observed. bad. Further, it is understood that the antimicrobial ceramic plate of Comparative Example 1 does not have antibacterial properties.

In Comparative Example 2, the silver content in the antibacterial composition was 70% by mass, and the mass ratio (A/P) of silver to phosphate glass was 2.33. Therefore, it was found that the antimicrobial ceramic plate did not have antibacterial properties.

In Comparative Example 3, since the amount of P ₂ O ₅ contained in the phosphate glass powder D is small, the loss of silver due to evaporation or diffusion of the silver component is suppressed during the firing of the antimicrobial glaze composition. The effect is not sufficient, so it is known that the antibacterial ceramic plate does not have antibacterial properties.

In Comparative Example 4, since the amount of Al ₂ O ₃ contained in the phosphate glass powder E is small, the water resistance is low, and when immersed in water at 50 ° C for 16 hours, silver is eluted together with P ₂ O ₅ . Antibacterial ceramic plates do not have antibacterial properties.

In Comparative Example 5, the amount of Na ₂ O and K ₂ O contained in the phosphate glass powder F was small, and therefore, silver could not be bonded to the phosphate glass, and during the baking of the antimicrobial glaze composition, the inhibition was The effect of the loss of silver due to evaporation or diffusion of the silver component is insufficient, and thus it is understood that the antimicrobial ceramic plate does not have antibacterial properties.

In Comparative Example 6, the content of silver relative to the glaze was 0.005% by mass, and thus it was found that the antimicrobial ceramic plate did not have antibacterial properties.

In Comparative Example 7, since the content of silver with respect to the glaze was 6% by mass, the antibacterial ceramic plate was colored, and the appearance was poor.

In Comparative Example 8, since the BET specific surface area of the silver-containing powder was 0.1 m ² /g, it was found that the antimicrobial ceramic plate did not have antibacterial properties.

In Comparative Example 9, since the average particle diameter of the antibacterial composition was 65 μm, it was found that the region showing the antibacterial property in the antibacterial ceramic plate was mixed with the region where the antibacterial property was not exhibited, and it was not practically applicable.

no

Fig. 1 is a scanning electron microscope (SEM) image showing an antimicrobial composition of Example 1 of the present invention. Fig. 2 is a view showing a reflected electron composition (COMPO) image of the antimicrobial composition of Example 1 of the present invention.

Claims (7)

An antibacterial composition comprising a mixture of a silver-containing powder and a phosphate glass powder, wherein the content of the silver-containing powder in the mixture is 5% by mass or more and 60% by mass in terms of silver Hereinafter, the mass ratio of the silver A to the phosphate glass P contained in the mixture, that is, A/P is 0.05 or more and 1.5 or less. The antibacterial composition according to the first aspect of the invention, wherein the phosphate glass powder is contained in an amount of 25% by mass or more as an oxide-converted component by a fluorescent X-ray measurement method. At least one selected from the group consisting of P ₂ O ₅ and 10% by mass or more and 35% by mass or less of Al ₂ O ₃ and a total of 10% by mass or more and 35% by mass or less selected from the group consisting of Na ₂ O and K ₂ O. . The antibacterial composition according to claim 1 or 2, characterized by comprising a secondary aggregate formed of the silver-containing powder and the phosphate glass powder, and using laser diffraction The average particle diameter measured by the scattering measurement method is 50 μm or less. The antibacterial composition according to any one of claims 1 to 3, wherein the silver-containing powder has a BET specific surface area of 0.2 m ² /g or more. The antibacterial composition according to any one of claims 1 to 4, wherein the silver-containing powder is composed of at least one selected from the group consisting of silver, silver phosphate, and silver oxide. Powder. An antibacterial composition and a glaze according to any one of claims 1 to 5, wherein the content of the antibacterial composition is relative to the glaze It is 0.01 mass % or more and 3 mass % or less in terms of silver. An antibacterial article characterized in that a film is formed by using the antibacterial glaze composition described in claim 6 of the patent application.