JP2945266B2 - Aluminum enamel plate with antibacterial and antifungal properties - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum enamel plate having antibacterial and antifungal properties, which is particularly preferably used as a building plate.

[0002]

2. Description of the Related Art An enamel is a material in which a glass component is thinly baked on the surface of a metal, and has both the robustness of metal, the touch resistance of glass, and the beauty of appearance,
Conventionally, it has been used in a wide range of fields such as kitchenware, medical equipment, and chemical containers. In particular, the aluminum enamel plate is suitable for use as a building plate. In recent years, from the viewpoint of increasing health concerns and hygiene, antibacterial substances such as AgO, CuO, ZnO, etc. are added to coatings such as colored steel plates, ceramics, and metal plates, and used for wall materials, objects, etc. Have been. When these substances elute on the surface, antibacterial properties and antifungal properties are exhibited.

[0003]

However, as for the enamel plate, even if an antibacterial substance such as AgO, CuO, ZnO or the like is added to the coating, the glass becomes Si in the firing process.
When forming and stabilizing the tetrahedral structure of O ₄ , these oxides are incorporated into the network structure, so that elution of the antibacterial oxide can hardly be expected, and the antibacterial property is not exhibited. was there.

[0004]

Accordingly, an object of the present invention is to provide an enamel plate having antibacterial and antifungal properties. According to the present invention, there is provided an aluminum enamel plate obtained by applying an enamel glaze to a surface of a steel plate plated with aluminum or an alloy thereof, and baking the enamel glaze with SiO ₂ , TiO ₂ , PbO, and , N
a ₂ O, K ₂ O, one or more alkali metal component selected from the group consisting of Li ₂ O as basic components, a total of 100 mole% composed of basic components, 30 to 45 moles of alkali metal components % Of an aluminum enamel plate having antibacterial and antifungal properties. Further, frit contains basic configuration in 100 mol% total consisting of components, from 62 to 52 mol% in total of SiO ₂ and TiO _2, a PbO 13 mol% or less, further, SiO ₂
It is preferable that the molar ratio of TiO ₂ to TiO ₂ is 5: 1 to 2: 1. Furthermore, 8 mol% of one or more compounds selected from the group consisting of ZnO, BaO and CdO is added to the frit, based on a total of 100 mol% of the basic components.
It is preferable that one or two or more compounds selected from the group consisting of the following and Al ₂ O ₃ and Sb ₂ O _3, in an amount of 6 mol% or less, and B ₂ O _3, 4 mol% or less are externally blended. In addition, a frit is added to a total of 100 mol% composed of basic constituents.
Further, 0.005 to 0.02 mol% of AgO may be compounded as an external agent, and the basic composition of the enamel glaze, which is a total of 100% by weight of frit, pigment, and electrolyte, is added to the enamel glaze. One or more metal oxides 1 to 5 selected from the group consisting of AgO, CuO and ZnO
% By weight may be compounded as an external agent.

[0005]

The aluminum enamel plate of the present invention is obtained by baking a glaze made of frit, pigment and other additives on the surface of a steel plate plated with aluminum or an alloy thereof. As the steel plate used for the aluminum enamel plate of the present invention,
Although the composition is not particularly limited, for example, manganese 0.2
5 wt% to 0.50 wt%, carbon 0.12 wt% or less,
It is preferable to use those containing 0.045% by weight or less of phosphorus and 0.050% by weight or less of sulfur in terms of appearance performance.
It is preferable to use aluminum containing 11% by weight or less of silicon and 4.5% by weight or less of iron from the viewpoint of adhesion to the enamel glaze.

Next, an example of a method for manufacturing an aluminum enamel plate of the present invention will be described. First, a pretreatment such as degreasing, pickling, and baking is performed on the surface of the aluminum or its alloy molded product. Next, 2 parts by weight of hydrous borax, 3 parts by weight of potassium silicate, and other additives are added to 100 parts by weight of the frit, and a pigment is added when coloring is required, so that particles having a diameter of 10 μm or more are added. Finely pulverize to less than% by weight to obtain a glaze. After glaze is applied to the surface of aluminum or its alloy, it is dried and fired. The firing is 550 lower than 650 ° C., which is the melting point of aluminum.
Perform at a temperature of around ° C.

In addition, the frit has a total of 62 to 52 mol% of SiO ₂ and TiO ₂ (SiO ₂ : TiO ₂ = 5: 1 to 1).
2: 1 (molar ratio)), with respect to a basic composition of 13 mol% or less of PbO and a total of 100 mol% of an alkali metal component of 30 to 45 mol%, at least one kind of ZnO, BaO and CdO in external form. To 8 mol% or less and Al ₂ O ₃ , Sb ₂ O ₃
6 mol% of one or more of the following, and B ₂ O ₃ is formed by blending 4 mol% or less, after mixing these 1150-12
Prepared by melting at 50 ° C. and quenching in water.

The frit used for the aluminum enamel plate of the present invention needs to be able to be fired at a temperature considerably lower than 600 ° C. which affects the structural strength of aluminum or its alloy. That is, 500 ° C
It is necessary to perform firing at 580C. In addition, it imparts acid resistance, alkali resistance, and weather resistance to the enamel plate, does not cause devitrification during the firing process, and gives a transparent, smooth and even enamel layer surface. Is required to have good adhesion and high thermal expansion necessary to maintain a non-crackable cross section.

The upper limit of 62 mol% of SiO ₂ and TiO ₂ is 5
It is a critical composition for obtaining a smooth and uniform glossy enamel layer surface having good acid resistance at a calcination temperature of 80 ° C. or lower. The lower limit of 52 mol% is a critical composition that does not cause white devitrification in the calcination process and does not reduce acid resistance. Further, the ratio between SiO ₂ and TiO ₂ affects the acid resistance of the aluminum enamel plate. PbO
Can be fired at a low temperature with a small amount of addition without deteriorating the chemical durability, but if added in a large amount, the chemical durability is significantly impaired in the firing process. 13 mol% of PbO upper limit
Is a critical composition for obtaining a smooth and uniform enamel layer surface at low temperature without reducing chemical durability.

When the content of the alkali metal component is less than 30 mol%, the thermal expansion of the frit becomes small, so that the thermal expansion of the frit cannot catch up with the thermal expansion of the base metal in the firing process, and a crack defect occurs on the surface of the enamel layer. . Further, when the content of the alkali metal component is larger than 45 mol%,
During the glaze preparation, the alkali component elutes, and the alkali component reacts with the base metal to generate gas, thereby deteriorating the adhesion between the base metal and the frit or generating bubbles in the enamel layer. . ZnO, BaO, and CdO are components that function to impart stable coloring to the enamel layer, and the upper limit thereof is ZnO, B
The total amount of aO and CdO is 8 mol%.

B ₂ O ₃ has the effect of improving the melting properties without deteriorating the chemical durability, but the upper limit is 4 mol% with respect to 100 mol% of the basic composition. Al ₂ O ₃ , S
Although b ₂ O ₃ has the effect of increasing the chemical durability, the upper limit is 6 mol% with respect to 100 mol% of the basic composition. Since the aluminum enamel plate of the present invention contains an alkali metal component in an amount of 30 to 45 mol%, free alkali deliquesces due to the humidity in the atmosphere, and the alkali component elutes on the surface of the enamel layer, thereby exhibiting antibacterial and antifungal properties. .

Further, in the present invention, since the content of SiO ₂ is relatively small, when AgO is added to the frit composition, Ag ions having antibacterial properties are eluted together with the alkali component, and the antibacterial properties of the aluminum enamel plate of the present invention are reduced. Further improve. This is because the amount of AgO is relatively large with respect to the amount of SiO _2, so that a part of AgO is not taken into the network structure of SiO ₄ but exists freely. AgO is S
iO _2, TiO _2, PbO, with respect to the basic composition is 100 mol% total consisting of alkali metal components from 0.005 to 0.
It is preferable to add 0.
It is more preferable to add 0.009 mol%,
It is more preferable to add from 0.05 to 0.007 mol%. Ag ions are considered to suppress the growth of bacteria by inactivating the SH enzyme group.

When one or two or more compounds selected from the group consisting of AgO, CuO and ZnO are added to the enamel glaze, these compounds are present in a state free from the network structure composed of SiO ₄ . The antibacterial effect is improved as compared with the case where it is added as a component of the frit. These compounds add 1 to a total of 100% by weight of the basic composition of frit, pigment and electrolyte.
It is preferably added in an amount of 5 to 5% by weight, more preferably 1 to 3% by weight, and even more preferably 1 to 2% by weight.

[0014]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

(Example 1) An aluminum enamel plate of the present invention was subjected to an antibacterial test. The aluminum used for the aluminum enamel plate was silicon of 11% by weight or less and iron of 4.5%.
Wt% or less, and the frit composition is SiO 2
_{2: 38.4, TiO 2: 12.8} , Na 2 O: 13.
9, K ₂ O: 10.5, Li ₂ O: 10.5, PbO: 1
_{1.6, Sb 2 O 3: 1.5} , B 2 O 3: 0.8 ( mol%)
Met. For comparison, stainless steel, a conventional enamel plate, and glass were used. The compositions thereof were stainless steel SUS304, a conventional enamel plate was an iron enamel (manufactured by Nippon Insulators Co., Ltd., product number 851), and glass was commercially available. Window glass (made by Asahi Glass Co., Ltd.).

First, in order to remove the fat component adhering to the surface of the test material, the test material was placed in a solution of Hirai S (main component: higher alcohol anion activator, non-ion activator) kept at 60 ° C. for 3 hours. Dipped. After washing with running water for 2 hours, it was dried, put in a sterilization can (cast), and sterilized in an autoclave at 121 ° C. for 20 minutes. Next, Escherichia coli and Staphylococcus aureus ( St.
aphylococcus aureus ), Candida albicans ( Can
dida albicans ), white fungus ( Trichophyton mentagraphyt)
es ) A bacterial suspension was prepared.

Escherichia coli and Staphylococcus aureus were cultured in a normal agar medium at 37 ° C. for 16 hours, collected in sterile physiological saline, washed twice at 3,000 rpm for 15 minutes, and washed at a constant volume. A bacterial suspension was prepared. Candida albicans was cultured on Sabouraud's glucose agar medium at 30 ° C for 3 days, collected in sterile physiological saline, and washed twice at 3000 rpm for 15 minutes to produce a certain amount of bacterial suspension. did. The white bacteria were cultured in a Sabouraud glucose bouillon medium containing 1% by volume of Tween 80 at 30 ° C. for 3 days, a turbid layer existing in the center of the medium was collected, and 3,000 rpm in sterile physiological saline.
Washing was performed twice under a centrifugation condition of m and 15 minutes to prepare a fixed amount of a bacterial suspension.

Next, the above bacterial suspension was applied to each test material and incubated. In a sterilized plate (30 × 50 mm) of each test material, 230 × 10 ³ E. coli and 200 × 1 E. coli S. aureus per cm ²
0 ^3, Candida albicans ^two 36 × 10, white鮮菌was smeared bacteria such that ^two 5 × 10. The plate was then placed in a wet container. FIG. 1 is a schematic diagram showing the structure of the wet container. As shown in FIG.
A sterilized U-tube 2 was placed at the center of the container, and sterilized water 3 was poured to prepare a wet container. Plate 4, coated with the bacterial suspension,
Place on U-tube 2 at 37 ° C for Escherichia coli and Staphylococcus aureus, 3 for Candida albicans and white bacteria.
Incubated at 0 ° C.

The number of surviving bacteria was calculated as follows. After a lapse of a predetermined time from the start of the incubation, the plate was placed in a beaker containing 100 ml of sterile physiological saline, and vigorously pipetted 30 times with a Komagome pipette for 30 seconds to wash out the bacteria. The thus-prepared bacterial solution was appropriately diluted, and 0.1 ml of E. coli and Staphylococcus aureus was spread on a normal agar medium, cultured at 37 ° C. for 48 hours, and the number of grown colonies was counted. And the number of surviving bacteria was determined. On the other hand, as for Candida albicans and white bacteria, an appropriately diluted bacterial solution was spread on a Sabouraud glucose agar medium, cultured at 30 ° C. for 72 hours, the number of grown colonies was calculated, and the number of surviving bacteria was determined.

The results are shown in Tables 1 to 4. The number in the table is 2
It is the average of two tests. In the table, 0 (× 10 ³ / cm ² )
The plate was washed with 100 ml of saline, and the
This indicates that no bacteria were detected even after culturing 1 ml.
That is, there is a possibility that 10 ³ or less bacteria survive on the plate. In addition, since the area of the plate is 30 × 50 mm, it indicates that the number of bacteria per 1 cm ^{2 of} the plate is 66 or less.

[0021]

[Table 1]

[0022]

[Table 2]

[0023]

[Table 3]

[0024]

[Table 4]

The aluminum enamel plate of the present invention comprises Escherichia coli,
Excellent antibacterial properties against Staphylococcus aureus compared to conventional enamel plates and stainless steel. In addition, it showed a slight antibacterial property against Escherichia coli, Staphylococcus aureus and white bacteria compared to glass. With respect to the conventional enamel plate and stainless steel, the growth of Candida albicans and white bacteria was slightly observed 24 hours after the start of incubation.

[0026]

According to the aluminum enamel plate of the present invention, the alkali metal component is used alone, or AgO, CuO, ZnO
It exhibits antibacterial and antifungal properties by being eluted on the surface of the enamel layer together with such metal oxides.

[Brief description of the drawings]

FIG. 1 is a schematic view showing the structure of a wet container.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Petri dish, 2 ... U-tube, 3 ... Sterilized water, 4 ... Plate

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C03C 8/12 C03C 8/12

Claims (5)

(57) [Claims] 1. An aluminum enamel plate obtained by coating and baking an enamel glaze on the surface of a steel plate plated with aluminum or its alloy, wherein the frit in the enamel glaze is SiO ₂ , Ti
One or more alkali metal components selected from the group consisting of O ₂ , PbO, and Na ₂ O, K ₂ O, and Li ₂ O are used as basic components, and a total of 10
In 0 mol%, the alkali metal component is 30 to 45 mol%
An aluminum enamel plate having antibacterial and antifungal properties, characterized by containing. Wherein the frit, in total 100 mole% composed of the basic components, 62 to 52 mol% in total of SiO ₂ and TiO _2, containing PbO 13 mol% or less, further, SiO ₂ the molar ratio of TiO ₂ is 5: 1 to 2: aluminum enamel plate according to claim 1 wherein the 1. 3. The frit contains ZnO, BaO and CdO in total of 100 mol% of the basic constituents.
And at least 8 mol% of one or more compounds selected from the group consisting of Al ₂ O ₃ and 6 mol% of one or more compounds selected from the group consisting of Sb ₂ O ₃ , and B ₂ O ₃ 4
The aluminum enamel plate according to claim 1 or 2, wherein less than mol% is externally blended. 4. The frit is further added to the frit in an amount of 0.005 to 0.0 with respect to a total of 100 mol% of the basic constituent components.
4. The method according to claim 1 , wherein 2 mol% of AgO is blended in an external manner.
2. The aluminum enamel plate according to claim 1. 5. An enamel glaze comprising: a frit, a pigment,
AgO, CuO and ZnO with respect to the basic composition of the enamel glaze of
The composition according to claim 1 , wherein 1 to 5% by weight of one or more metal oxides selected from the group consisting of :
5. The aluminum enamel plate according to any one of items 1 to 4 .