JP3026732B2 - Construction method of antibacterial glass coating - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a construction method of a glass cover with anti-fungal.

[0002]

2. Description of the Related Art Glass-coated products, such as glass lining and enamel, which fuse and coat glass on the surface of a base material made of metal or the like, require chemical industrial equipment that requires corrosion resistance and aesthetic treatment of the surface. Widely used for building materials and daily necessities.

[0003]

In the case of such chemical industrial equipment, particularly food and pharmaceutical equipment, building materials and daily necessities, the surface of the glass coating layer has an antibacterial property capable of preventing the generation of algae and bacteria. If there is, it will be even more useful. Therefore, it is conceivable that the surface of the glass coating layer contains metal ions which are conventionally known to have antibacterial properties, for example, silver and copper ions.

Conventionally, gas in order to incorporate the metal ions into glass, moistened with metal such as silver during the melting of the glass
There is a method of manufacturing tiles and enamel products using lath as an upper glaze, but in such a case, there is a problem that the concentration of silver contained in the glass is low and the antibacterial effect is not sufficient. I was

In addition, it is difficult to contain metal ions on the surface of a glass coating layer applied to a large product such as industrial equipment or a product having a complicated shape, and there has been a problem that the production cost is too high.

Furthermore, if the metal ions are not uniformly contained on the surface of the glass coating layer, the antibacterial properties become uneven, and there is a possibility that bacteria or algae may be partially formed, so that foods and foods may be used. It was unsuitable for pharmaceutical equipment.

The present invention has been made in order to solve such problems, and an object of the present invention is to provide a glass-coated product having high antibacterial properties and easy to apply.

[0008]

Means for Solving the Problems The present invention has been Do to solve such problems, to solve the problem
The means for this is the surface of the glass coating layer formed on the substrate.
Add antibacterial metal salt and fine powder to solvent and mix
After applying the prepared coating agent, the coating agent is dried after application.
After drying, at a temperature above the glass transition point
Heat to deposit metal ions from the metal salt on the surface of the glass coating layer.
After being contained, the coating agent is removed.

[0009]

[0010]

The surface of the glass coating layer is coated with a coating agent containing a metal salt having an antibacterial property that can be replaced with alkali ions contained in the glass coating layer, and the metal ions generated from the metal salt during the baking treatment are applied. Since metal ions are contained in the surface of the glass coating layer by substitution and diffusion with alkali ions by ion exchange, the surface of the glass coating layer can easily contain a uniform and high concentration of antibacterial metal ions.

[0011] Further, since the coating agent contains fine powder such as Aerosil, the strength of the dried film increases when the coating agent is dried, and the coating agent is partially peeled off. Non-uniform replacement of metal ions can be prevented in a non-uniform manner, and further, there is no need to perform work such as re-coating of the peeled-off coating agent, so that work efficiency is improved.

When a dispersant is contained in the coating agent, the liquid component and the solid component are not easily separated and settled during application of the coating agent, so that the coating can be easily applied and the coating operation can be performed quickly.

Further, when the coating agent contains an ion exchange aid, ion exchange is promoted, so that metal ions can be more effectively contained on the surface of the glass coating layer.

When the surface of the glass coating layer contains metal ions at a concentration of 5 to 15%, a glass coating product having high antibacterial properties can be formed.

[0015]

Embodiments of the present invention will be described below. First, a method of applying a glass coating layer on a base material such as stainless steel, for example, on the inner surface side of a stainless steel container for storing food, medicine, and the like inside will be described.

First, a subbing glass layer is formed to strengthen the bond between the substrate and the glass coating layer. The undercoat glass layer is formed by applying a glass powder for the undercoat glass layer to the surface of the base material by spraying or the like, and then baking in a furnace at about 850 ° C.

Next, an upper glass layer is formed on the upper surface of the lower glass layer. The glass layer having a predetermined thickness is also formed by repeating the application of the glass powder by spraying or the like and firing in an oven at about 650 ° C. two to three times.

The glass coating layer comprising the undercoating glass layer and the overcoating glass layer thus formed contains metal ions.

First, a paste-like coating agent is applied to the surface of the glass coating layer. The coating agent is obtained by mixing silver sulfide or silver chloride as a metal salt with pure water as a solvent, chromium oxide as an ion exchange aid, activated alumina as a dispersant, zirconium hydroxide, zirconium oxide. Aerosil, which is a submicron fine particle of silicon oxide, in an appropriate ratio, in this embodiment, pure water 100, silver sulfide 30 as a metal salt, zirconium oxide 60, aerosil 0.5, chromium oxide 0.5 (All by weight) and formed into a paste.

When pure water is used for the coating agent, ion exchange is not performed uniformly when impurities are mixed.
This is to prevent this.

Further, at the time of application, the action of the dispersant prevents the solid content in the application agent from precipitating and making application difficult, so that the application operation can be performed promptly.

After applying such a paste-like coating agent on the surface of the glass coating layer, the coating agent is dried.

After the drying, since Aerosil as a fine powder is mixed as described above, the drying strength of the coating agent is increased, and the coating agent is not cracked and peeled off. No additional work is required.

After drying of the coating agent, the temperature is slightly higher than the glass transition temperature of the glass component of the glass coating layer. In this embodiment, the glass transition temperature is about 420 ° C. Heat treatment is performed at a temperature of about 470 ° C. for about 1 to 2 hours.

If the heat treatment is performed at a temperature higher than this temperature, the glass coating layer may be softened and the coating agent may enter the glass layer. If the heat treatment is performed at a temperature lower than this temperature, Since the replacement of ions by ion exchange hardly occurs, it is preferable to perform the heat treatment at a temperature within the above range.

By the heat treatment, silver ions from the silver sulfide in the coating agent are removed from the surface of the glass coating layer to a certain thickness.
It is replaced by alkali ions in the glass coating layer.

By adjusting the heat treatment time,
The amount of silver ions substituted into the glass coating layer is 5 to 15
%, But it is particularly desirable that a high concentration of metal ions of 10% or more be contained near the surface of the glass coating layer. In this embodiment, about 10% or more of metal ions can be contained in the vicinity of the surface of the glass coating layer, and silver ions can be contained up to a thickness of about 300 μm.

After the heat treatment and further cooling, the coating agent is washed with water and completely removed from the surface of the glass coating layer.
After the washing, all the coating agents other than the silver ions substituted for the glass coating layer are removed, and no unnecessary coating agent or the like remains on the surface of the glass coating layer.

Next, the following experimental results are shown with respect to the antibacterial properties of the glass-coated product having antibacterial properties containing silver ions as described above.

Experimental Results 1 After soda lime glass having a coefficient of thermal expansion of 100 × 10 ⁻⁷ / ° C. was glass-lined on mild steel, the above paste-like coating agent was applied by spraying and dried at 530 ° C. Heat treatment was performed for 2 hours. After cooling, wash with water to remove residual coating agent,
An antibacterial test was performed on a metal-exposed portion coated with a resin.

As test bacteria, Escherichia coli (Esherichia coli) as Escherichia coli, Staphylococcus aureus (Staphylococcus aureus) as Staphylococcus aureus,
Candida albicans as a fungus
It was used. A culture solution of the test bacteria shaken in a bouillon medium at 35 ° C. for 20 hours is diluted so that the number of bacteria is about 10 ⁸ / ml, and then diluted 0.5 times with a sterile phosphate buffer solution to 1000-fold.
1 was dropped on the glass surface of the product, and the viable cell count of the specimen after storage at 25 ° C. for 24 hours and 48 hours was measured. The same test was performed using a control sample prepared by dropping 0.5 ml of the bacterial solution on a petri dish. The results are as shown in Table 1.

[0032]

[Table 1]

As is clear from the above results, all the cells were completely killed after 24 hours, confirming the antibacterial effect of the glass-coated product ion-exchanged with silver.

Experimental Result 2 A soda lime glass having a coefficient of thermal expansion of 150 × 10 ⁻⁷ / ° C. was placed on a portion of stainless steel having a diameter of 24 mm and a thickness of 2 mm (ends chamfered) having a diameter of 10 mm from the center of one side. After leaving the glass lining, the coating agent was applied by spraying, dried and then heat-treated at 430 ° C. for 2 hours. After cooling, the coating was washed with water to remove the residual coating agent, and an antibacterial test was performed on the exposed metal with resin coating.

A halo test was performed for the antibacterial test. The halo test uses a petri dish in which agar is poured, and a bacterial solution is applied on the agar, and a sample is placed on the agar. This test measures the width of the inhibition zone (halo) generated around the sample after culturing at 27 ° C. for 48 hours. As test bacteria, Escherichia coli (Esherichia coli) as E. coli, Staphylococcus aureus (Staphylococcus aureu) as Staphylococcus aureus
s), Candida albicans (Candida albi
cans).

[0036]

[Table 2]

From the above results, a zone of inhibition was confirmed in each of the cells. Therefore, the antibacterial effect of the glass-coated product ion-exchanged with silver was confirmed.

In the above embodiment, pure water was used as a solvent for the coating agent. However, use of such pure water is not a condition, and ordinary tap water may be used. Further, an organic solvent such as ethanol may be used instead of pure water as the solvent. When such an organic solvent is used, even if dirt such as oil is attached to the surface of the glass coating layer, it can be removed simultaneously with the application.

If oil has adhered to the surface of the glass coating layer, ion exchange is difficult in this portion, and the metal content becomes non-uniform. Although the layer surface is washed, such a washing step can be omitted by mixing an organic solvent such as ethanol with the coating agent in advance.

As such an organic solvent, in addition to ethanol, other organic solvents capable of dissolving an oil such as acetone can be used as appropriate. However, when ethanol is used, there is an advantage that handling is easy and economical.

In the above embodiment, silver sulfide was used as the metal salt to be mixed with the coating agent. In addition, any metal salt of an antibacterial metal such as silver, copper or tin may be used. Two or more of the above may be mixed.

Further, in the above embodiment, Aerosil was used as the fine powder to be mixed in the coating agent. However, the fine powder is not limited to Aerosil, but may be alumina,
Fine powder such as zirconium oxide can be used as appropriate.

In the above embodiment, chromium oxide, activated alumina, zirconium hydroxide and zirconium oxide as a dispersant and an ion exchange aid were mixed in the coating agent. However, the use of these was not a condition. Moreover,
One of these may be used, or two or more of them may be used in combination.

Further, in the above embodiment, the glass coating layer was formed from the undercoating glass layer and the overcoating glass layer. However, a single glass coating layer may be used. There is no particular limitation as long as it is a glass coating layer having a component that can be replaced with a metal ion having

In the above embodiment, the glass coating layer is formed on the inner surface of a stainless steel container or mild steel as a base material. However, the base material may be aluminum, copper, ceramic, brass, etc. in addition to stainless steel and mild steel. Any material that can be coated with glass can be used, and furthermore, it can be easily applied not only to the inner surface side of the container, but also to parts of complicated shapes such as machine parts.

[0046]

As described above, the present invention can provide a glass-coated product having high antibacterial properties in which the surface of the glass coating layer contains metal ions having antibacterial properties in a uniform and high concentration. Further, there is an effect that such a work of applying the glass coating can be performed easily and quickly.

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields investigated (Int. Cl. ⁷ , DB name) C03C 17/00-21/00 A01N 25/34 A01N 59/16 C23C 24/00 C23D 13/00

Claims (6)

(57) [Claims] On the surface of the 1. A glass coating layer formed on the substrate, a metal salt and powder having antimicrobial properties by coating the coating agent mixed formulated in addition to the solvent, drying the coating agent after coating, further After drying, heating at a temperature above the transition point of the glass to contain metal ions from the metal salt on the surface of the glass coating layer, and then removing the coating agent, the application of antibacterial glass coating construction Method. Wherein said fine powder is Aerosil claim 1
The method for applying a glass coating having antibacterial properties according to item 1. 3. The glass coating layer has a surface content of 5 to 15% by weight.
The method for applying a glass coating having antibacterial properties according to claim 1 or 2 , wherein the metal ion is contained. 4. The method of claim wherein the metal ion is silver ion
The method for applying an antibacterial glass coating according to any one of claims 1 to 3 . 5. The claims contain dispersing agent to the coating agent
The method for applying a glass coating having antibacterial properties according to any one of claims 1 to 4 . 6. A method of constructing a glass coating having antimicrobial properties as claimed in any one of the coating agent according to claim contains ion exchange aids in 1 to claim 5.