JP2000053451A - Antibacterial glass product and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce an antibacterial glass product excellent in antibacterial effect in spite of a relatively small amt. of an antibacterial component, suppressing coloring due to the antibacterial component and preventing the lowering of the transparency and to provide an easy and inexpensive production method therefor. SOLUTION: A dispersion of fine particles of silver or its compd. or a soln. of silver or its compd. is applied to the surface of a glass product and ions in the glass are exchanged for silver ions by heat treatment to produce the objective antibacterial glass product contg. silver ions substd. by ion exchange at 0.5-10,000 ppm concn. in the surface layer of the glass product.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention is excellent in antibacterial effect,
The present invention relates to an antibacterial glass product in which coloring due to an antibacterial component is suppressed and a decrease in transparency is prevented, and a method for producing the same. In addition, in this specification, antibacterial property shall also mean antifungal property and antialgal property.

[0002]

2. Description of the Related Art Conventionally, as an antibacterial glass product, a dispersion or solution of silver fine particles is applied to the surface of the glass product and then heat-treated to diffuse and carry the silver fine particles inside the glass product surface layer. It has been known. In order to improve the diffusivity and secure the diffusion amount and the diffusion depth of silver, the smaller the particle size of the silver fine particles to be used, the better, and the heat treatment temperature is preferably high. Usually, it is heat-treated at a temperature of about 400 to 600 ° C.

[Problems] However, the prior art has the following problems. When Ag ions are used as silver fine particles, they are reduced to metallic Ag and easily colored. Aggregation and fusion of silver fine particles easily occur inside the surface layer, and coloring is easy. The silver fine particles agglomerate and fuse to reduce the silver surface area and the antibacterial effect becomes insufficient.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the problems in the prior art, and an object set specifically to solve the problems is a relatively small amount of antibacterial activity. An object of the present invention is to provide an antibacterial glass product which has an excellent antibacterial effect regardless of the amount of the component, and in which coloring due to the antibacterial component is suppressed, and a simple and inexpensive method for producing the same.

[0005]

Means for Solving the Problems Claim 1 of the present invention
The antibacterial glass product according to the above is characterized in that the surface layer of the glass product contains silver ions replaced by ion exchange with ions in the glass at a concentration of 0.5 to 10,000 ppm.

The antibacterial glass product according to claim 2 is characterized in that the range in which silver is substantially detected is from the surface to a depth of 5 to 30 μm.

According to a third aspect of the present invention, there is provided a method for producing an antibacterial glass product, wherein a dispersion or solution of fine particles of silver or a silver compound is applied to the surface of the glass product and heat-treated to form silver ions and ions in the glass. Is subjected to ion exchange.

In a fourth aspect of the present invention, there is provided a method for manufacturing an antibacterial glass product, wherein the temperature of the heat treatment is 300 ° C. or less.

[0009]

Embodiments of the present invention will be described below in detail. This embodiment is specifically described for better understanding of the spirit of the invention, and does not limit the contents of the invention unless otherwise specified.

The antibacterial glass product in this embodiment is obtained by introducing silver as an antibacterial component at a relatively low temperature from the surface of the glass product to the inside of the surface layer. 0.5 to 10,000pp
Silver ions with the highest concentration on the surface, the lower the concentration as they progress into the interior, and silver is introduced in such a way that the silver is practically detected in a depth of 5 to 30 μm from the glass product surface. In addition, it mainly exists in a state of being ion-exchanged with ions in the glass.

The phrase "mainly present in an ion-exchanged state" means that some silver after diffusion is present as silver particles at grain boundaries or the like to such an extent that the antibacterial effect is not impaired. Further, the glass products include not only glass plate-shaped materials, but also articles having an arbitrary shape such as a glass and articles surface-coated with a vitreous substance such as an enamel or a glaze.

The silver concentration of the glass product surface layer is 10,000 p
When the pressure exceeds pm, the strength of the glass product deteriorates,
Or there is a problem such as coloring becomes noticeable,
If the silver concentration is less than 0.5 ppm, the antibacterial properties of the entire glass product surface cannot be maintained at a practically sufficient level. Also, even if silver ions as antibacterial components are distributed deeper than 30 μm from the glass product surface,
The silver ions have little relation to the antimicrobial properties.

[0013] The heat treatment temperature is preferably 300 ° C or less, particularly preferably 200 ° C or less. That is, when heat treatment is performed at a temperature of 300 ° C. or more, silver aggregates and fuses inside the surface layer of the glass product to become coarse and hard to be ionized, so that it is difficult to exchange ions. In addition, the surface area of silver is reduced due to aggregation and fusion, and the surface area of the silver is reduced, and the activity, that is, the oligodionomy effect of silver is reduced, and the antibacterial property is not sufficiently exhibited. Become.

Further, since the method is based on a production method in which a dispersion or solution of silver or a silver compound (hereinafter referred to as an antibacterial coating liquid) is applied to the surface of a glass product at a high temperature and heat-treated,
Countless minute cracks are likely to be generated on the surface of the glass product, which causes a decrease in transparency.

An appropriate heat treatment temperature is appropriately selected from, for example, a temperature of 300 ° C. or less in consideration of the type of glass product imparting antibacterial properties, the type of silver or silver compound used, the depth of introduction, and the like. The heat treatment time also varies depending on the type of glass product imparting antibacterial properties, the type of antibacterial component, the depth at which the antibacterial component is introduced, and the like, but is usually about several seconds to several tens of hours. Various heat treatment steps during the glass product manufacturing process can be used for the heat treatment, and the antibacterial coating solution may be applied directly to the glass product in the course of manufacturing.

The atmosphere during the heat treatment is not particularly limited.
If there is any influence, for example, a non-oxidizing atmosphere is used. During the heat treatment, pressure may be applied to such an extent that the glass product is not affected. Pressing can shorten the heat treatment time,
It can be introduced deeper. The method of applying the antibacterial coating solution includes dip, spraying, and brushing, and is not particularly limited.

Silver fine particles or silver compounds are used as the antibacterial component. The silver compound is not particularly limited, but one containing no component remaining after the heat treatment is used.
Suitable silver compounds include, for example, silver citrate, silver lactate, silver soap, and the like, for ease of introduction into the interior from the glass product surface, safety, and the like, because the surface properties of the glass product, for example, do not affect the color tone. Any one or two of inorganic silver compounds such as silver chloride, silver sulfide, silver sulfate, silver oxide and the like, a silver complex with a compound having coordination ability such as ammonia and thiosulfuric acid The above is preferable.

The antibacterial coating solution is obtained by dispersing or dissolving the fine particles of the above antibacterial component, and has properties such as dispersion stability of the antibacterial component, applicability to the glass product surface, and ion exchange property. For improvement, organic solvents, surfactants, soluble or emulsion type organic resins, soluble organic acid salts, condensed sodium phosphate, sodium thiosulfate,
Those containing at least one selected from the group consisting of ammonia are preferred.

Examples of the organic solvent include alcohols such as methanol and ethanol; cellosolves such as methyl cellosolve, ethyl cellosolve and butyl cellosolve; acetone;
Ketones such as ethyl methyl ketone and ethers such as diethyl ether can be suitably used. The amount is not particularly limited, and is appropriately determined in consideration of the drying speed and the like.

As the surfactant, any of nonionic, anionic and cationic surfactants can be used. The blending amount is not particularly limited, but is usually about 0.01 to 1% by weight, and there is no difference in effect even if the blending amount is larger than this.

As the soluble or emulsion type organic resin, a water-soluble acrylic resin, acrylic emulsion, polyvinylpyrrolidone, polyvinyl alcohol and the like can be suitably used. The amount is not particularly limited, but is preferably 0.1 to 10% by weight, since an appropriate viscosity can be obtained.

A soluble organic acid salt, a condensed sodium phosphate,
The amounts of sodium thiosulfate and ammonia are not particularly limited, but are usually about 0.01 to 1% by weight, respectively. In addition, as a soluble organic acid salt, sodium citrate, sodium lactate, sodium acetate, calcium citrate,
Examples thereof include calcium lactate and calcium acetate.

The antibacterial coating solution preferably contains condensed sodium phosphate and cellosolve as additives. Among them, the cellosolve is not particularly limited, but butyl cellosolve is preferred in that the silver fine particles can be miniaturized.

That is, a condensed sodium phosphate and, for example, butyl cellosolve are added to a dispersion of fine metal silver particles,
When left untreated, metal silver fine particles are miniaturized to achieve extremely excellent dispersion stability, excellent diffusion from the glass product surface to the inside of the surface layer, and even silver or silver compounds having low ionicity as antibacterial components. Even when used, it is easily ionized even at the time of heat treatment at a relatively low temperature, for example, at a temperature of 300 ° C. or less, and is easily exchanged with ions in the glass.
In addition, since it has excellent coatability, a uniform antimicrobial layer can be formed over the entire desired surface of the glass product.
And there is no influence on the surface color of the glass product.

The antibacterial component concentration of the antibacterial coating solution is 0.001 to
10% by weight is preferable. If it is thinner than this, sufficient antibacterial properties cannot be obtained. If it is thicker than this, a fused film of antibacterial components is formed on the glass product surface, dirt often remains, and The silver ion concentration in the surface layer of the product
It becomes difficult to make it 0.5 to 10,000 ppm.

The particle size of the antibacterial component in the antibacterial coating solution is preferably 10 μm or less, particularly preferably 0.05 μm or less. Especially when using antibacterial components of 0.05 μm or less,
Even if silver or a silver compound having low ionicity is used as the antibacterial component, it is easily ionized and easily exchanged with ions in the glass during heat treatment at a temperature of 200 ° C. or lower.

After the heat treatment, the antibacterial component may form a fused film on the surface of the glass product or impurities may remain, which can be easily removed by washing with an acid or alkali. In addition, since the antibacterial component is introduced inside the surface layer of the glass product, the antibacterial property does not disappear or decrease even if the fusion film or the residue is removed, and still retains a good antibacterial property. .

[0028]

EXAMPLES Example 1 A coating solution having the following composition was used as an antibacterial coating solution. Silver lactate concentration 0.5% by weight (silver ion concentration 0.25% by weight) Condensed sodium phosphate 0.1% by weight Butyl cellosolve 10.0% by weight Water Remainder This antibacterial coating solution is applied to a dense soda-lime glass plate (density approx.
100%, glass softening point 540 ° C) by dipping (silver coating amount 0.1g / m ² ), dried, and in air at a temperature of 1
After heat treatment at 80 ° C for 30 minutes, the antibacterial treated surface was pickled to obtain an antibacterial glass plate.

When the surface of the antibacterial glass plate was observed with a scanning microscope, no fine cracks were observed.
Further, when the abundance of silver was analyzed by glow discharge mass spectrometry, 1000 ppm of silver was confirmed on the surface, and the average depth was 5 ppm.
The presence of silver was confirmed up to μm. Further, when this antibacterial glass plate was immersed in warm water at 50 ° C. for 3 days, elution of silver ions was confirmed by an atomic absorption method. In addition, it was visually confirmed that this antibacterial glass plate had excellent transparency as before the antibacterial treatment and was not colored at all.

Example 2 An antibacterial ceramic plate was obtained in the same manner as in Example 1 except that a glazed ceramic plate (melting point of the glaze was 1000 ° C.) was used as a glass product. Observation of the surface of this antibacterial ceramic plate according to Example 1 revealed no fine cracks, and analysis of the amount of silver by glow discharge mass spectrometry showed that 1200 ppm of silver was found on the surface. Was confirmed, and the presence of silver was confirmed up to an average depth of 8 μm. Further, when elution of silver ions was confirmed in accordance with Example 1, the presence of silver ions was confirmed. In addition, this antibacterial ceramic plate was visually confirmed to have no change in color tone.

Example 3 An antibacterial coating solution having the following composition was used, and the heat treatment temperature was set to 300 ° C.
An antibacterial glass plate was obtained according to Example 1. Silver fine particles having an average particle diameter of 3 nm 0.1% by weight Condensed sodium phosphate 0.1% by weight Butyl cellosolve 10.0% by weight Water balance

When the surface of the antibacterial ceramic plate was observed in accordance with Example 1, no fine cracks were observed. When the amount of silver was analyzed by glow discharge mass spectrometry, 950 ppm And the presence of silver was confirmed up to an average depth of 6 μm. Further, when elution of silver ions was confirmed in accordance with Example 1, the presence of silver ions was confirmed. In addition, this antibacterial ceramic plate was visually confirmed to have no change in color tone.

Comparative Example 1 An antibacterial glass plate was obtained in the same manner as in Example 1 except that the heat treatment temperature was 350 ° C. When the surface of this antibacterial glass plate was observed according to Example 1,
Example 1 Many fine cracks were formed in the form of stripes.
When elution of silver ions was confirmed according to the above, elution of silver ions was not confirmed. In addition, it was visually confirmed that the antibacterial glass plate had reduced transparency and was colored.

Comparative Example 2 An antibacterial ceramic plate was obtained in the same manner as in Example 2 except that the heat treatment temperature was changed to 320 ° C. Observation of the surface of the antibacterial ceramic plate according to Example 1 revealed that many fine cracks were formed in a streak shape, and elution of silver ions was confirmed according to Example 1. Not confirmed. The antibacterial ceramic plate was visually confirmed to have slightly changed color tone.

Comparative Example 3 An antibacterial glass plate was obtained according to Example 3, except that the heat treatment temperature was 350 ° C. When the surface of this antibacterial glass plate was observed according to Example 1,
It was confirmed that many fine cracks were formed in the form of stripes, and that silver aggregates and fusions were formed in spots along the grain boundaries. When the elution of silver ions was confirmed according to Example 1, the elution of silver ions was not confirmed. Furthermore,
This antibacterial glass plate was visually confirmed to have reduced transparency and to be colored.

[Evaluation of Antibacterial Property] Examples 1 to 3 and Comparative Example 1
The resistance (antibacterial property) to various fungi of the antibacterial glass products prepared in Nos. To 3 was evaluated in association with each other. That is, 0.1 ml of each bacterial solution of Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae, Salmonella, and Pseudomonas aeruginosa was placed on the surface of the antibacterial glassware, and the number of surviving bacteria after standing at 37 ° C for 24 hours was agar. It was measured by the plate method. The results are shown in Tables 1, 2 and 3, respectively.

[0037]

[Table 1]

[0038]

[Table 2]

[0039]

[Table 3]

The antibacterial glass products prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were evaluated for their resistance to mold and algae (antifungal and antialgal properties). That is, molds and algae were cultured on the surfaces of these antibacterial glassware at 27 ° C. for a predetermined time, and the occurrence was visually observed according to the following evaluation criteria. 0… No mold and algae generated 1… There was only a few molds and algae generated 2… Moderately generated molds and algae 3… Many molds and algae generated 4… Mold and algae generated all over Yes The results are shown in Table 4.

[0041]

[Table 4]

[Evaluation Results] Based on the above results, Examples 1 to
It was confirmed that the antibacterial glass product according to No. 3 was superior to the glass products according to Comparative Examples 1 to 3 also in antibacterial property, antifungal property, and antialgal property. In addition, it was confirmed that coloring caused by silver as an antibacterial component was suppressed, and there was no decrease in transparency. Furthermore, from the results of the hot water immersion test, it was found that silver was ion-exchanged with ions in the glass in the antibacterial glass products according to Examples 1 to 3.

[0043]

As described above, in the antibacterial glass product according to the first aspect of the present invention, the surface layer of the glass product contains 0.5 to 10,000 silver ions substituted by ion exchange with ions in the glass.
Since it is contained at a concentration of 00 ppm, it is excellent in antibacterial properties, antifungal properties, and antialgal properties in spite of a relatively small amount of antibacterial components, and furthermore, coloring caused by silver, which is an antibacterial component, is suppressed. And has an excellent effect that there is no decrease in design.

In the antibacterial glass product according to the second aspect, the range in which silver is substantially detected is 5 to 30 depths from the surface.
Since the particle size is not more than μm, silver, which is an antibacterial component, can be supported in a range where the antibacterial property can be exhibited, and the antibacterial component can be supported without waste.

In the method for manufacturing an antibacterial glass product according to the third aspect, the manufacturing method is extremely simple by applying a dispersion or solution of fine particles of silver or a silver compound to the surface of the glass product and heat-treating the glass product for ion exchange. In addition, silver atoms can be efficiently introduced into the surface layer of a glass product and can be carried by an ion exchange reaction, and an antibacterial glass product having excellent antibacterial, antifungal and antialgal properties can be produced at low cost. Further, it is possible to obtain an antibacterial glass product in which coloring due to silver, which is an antibacterial component, is suppressed and there is no deterioration in design.

In the method for producing an antibacterial glass product according to the fourth aspect, since the treatment temperature of the heat treatment is 300 ° C. or less, ionized silver is supported without causing aggregation and fusion of silver. Thus, an antibacterial glass product excellent in antibacterial properties, antifungal properties, and antialgal properties can be easily obtained.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasuyuki Kurino 585 Tomimachi, Funabashi-shi, Chiba Sumitomo Osaka Cement Co., Ltd. 4C058 AA06 AA30 BB07 JJ05 JJ28 4G059 AA01 AC30 HB02 HB17

Claims (4)

[Claims] A surface layer of a glass product is provided with silver ions, which have been replaced by ion exchange with ions in the glass, in an amount of 0.5 to 10,000.
An antibacterial glass product which is contained at a concentration of 00 ppm. 2. The antibacterial glass product according to claim 1, wherein the range in which silver is substantially detected is from a surface to a depth of 5 to 30 μm. 3. A process for producing an antibacterial glass product, characterized in that silver or a silver compound fine particle dispersion or solution is applied to the surface of a glass product and then heat-treated to exchange silver ions with ions in the glass. Method. 4. The method for producing an antibacterial glass product according to claim 3, wherein the temperature of the heat treatment is 300 ° C. or lower.