JP2957125B2 - Antibacterial painted metal plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention is used in hospital-related materials, kitchen utensils, home hygiene products, home electric appliances, etc. for the purpose of sterilizing or suppressing the growth of fungi such as molds and yeasts, and bacteria such as pathogens and various germs. Antibacterial painted metal sheet.

[0002]

2. Description of the Related Art As this kind of antibacterial coated metal plate, for example, as disclosed in Japanese Patent Application Laid-Open No. Hei 7-313935, a thiazole-based, imidazole-based, thiazoline-based or other organic eluting antibacterial agent is used as a resin. Some are mixed with paint and painted on metal plates.

[0003]

However, those using the above-mentioned organic eluting antibacterial agents exhibit an antibacterial effect at an early stage, but are depleted due to elution of the drug with the passage of time. It has a short-lasting effect and has an antibacterial effect against mold, but has a low antibacterial effect against bacteria and has a problem that if the baking and drying temperature of the paint is high, the antibacterial effect is almost eliminated because the active ingredient is thermally decomposed. . On the other hand, a metal plate coated with a paint containing an inorganic silver-containing zeolite-based antibacterial agent is also known, but this is effective only for bacteria that have come into contact with the surface of the metal plate. Has no antibacterial effect when it adheres, and has a limited antibacterial effect.
+ Is present and is made chemically. The antibacterial effect of silver ions is weakened when dust in the air is charged and adhered to the surface of a metal plate. Silver ions are sterilized by an oligodynamic action. Although it exerts its effect, it has a problem that the antibacterial effect is reduced because a passive oxide film of silver oxide is formed on the outer surface of the metal plate upon contact with water or air. The present invention has been made in order to solve the above-mentioned problems. In a metal plate which is coated with an inorganic antibacterial agent in a resin coating and baked, the composition of the inorganic antibacterial agent and the compounding ratio thereof It is an object of the present invention to provide an antibacterial coated metal plate that can enhance the fungicidal and bacterial germicidal and propagation inhibiting effects by devising the above.

[0004]

According to the present invention, there is provided an antibacterial coating film containing 0.05 to 50 parts by weight of a powdery antibacterial agent per 100 parts by weight of a solid content of a resin coating on the surface of a metal plate. An antibacterial coated metal plate that has been coated and baked and dried at a plate temperature of 170 to 260 ° C, wherein the antibacterial agent has an average particle size of 1
μm or less, and silicon carbide or silicon oxide is 30 to 80
Weight%, alumina oxide 9-40 weight%, manganese oxide 0.1-15 weight%, zinc oxide 0.1-15 weight%, titanium oxide 9-30 weight%, silver or copper 1 weight%
It is characterized by being fired at the following ratio.
After forming an undercoat layer on the surface of the metal plate, the antibacterial coating can be applied and baked on the undercoat layer. Further, the antibacterial coating film can be applied and baked on both surfaces of the metal plate.

[0005]

The antimicrobial agent comprising the above composition emits electromagnetic waves in the infrared region, and resonates and excites the water molecules of bacteria forming environmental bacteria and the environmental moisture essential for the propagation of the bacteria. It can inhibit the physiology of the body and suppress the growth of bacteria. If the antibacterial agent is less than 0.05 part by weight with respect to 100 parts by weight of the solid content of the resin coating, the antibacterial effect is weak, and if it exceeds 50 parts by weight, it does not contribute much to the improvement of the antibacterial effect at the time of use. This is not only wasteful, but also reduces the workability of the coating film. More preferably, it is 0.5 to 3 parts by weight. The above-mentioned inorganic antibacterial agent does not deteriorate even when painted on a metal plate and baked at a high temperature of 170 to 260 ° C.

By setting the average particle size of the antibacterial agent to 1 μm or less, the radiation efficiency of electromagnetic waves in the infrared region can be increased by increasing the surface area ratio. Silicon carbide or silicon oxide emits electromagnetic waves almost uniformly in the near infrared to far infrared region, and resonates and excites water molecules to suppress the growth of bacteria. However, silicon carbide or silicon oxide is 30
It is effective if the mixing ratio is up to 80% by weight.

[0007] Alumina oxide can radiate electromagnetic waves in the far-infrared region, thereby suppressing the growth of bacteria. Further, it acts to cause reduction of silver or copper, which will be described later, due to the difference in ionization tendency. However, alumina oxide is 9% by weight.
If the amount is less than 40% by weight, the effect is good.

[0008] Manganese oxide functions as a catalyst for titanium oxide and activates it, increasing the oxidizing power of titanium oxide and increasing its sterilizing power. To promote the reduction action of titanium oxide, manganese oxide is added in an amount of 0.1 to 15% by weight. However, the effect of manganese oxide is good when it is less than 0.1% by weight, and the effect is saturated when it exceeds 15% by weight.

[0009] Since zinc oxide has a higher ionization tendency than silver or copper, it reduces silver and copper in an environment of high humidity and erases a passive oxide film formed on the outer surface of the coated metal plate, thereby producing an antibacterial agent. The effect is exhibited continuously. Zinc oxide also increases the sintering bond strength. Zinc oxide exerts its effect when it is added in an amount of 0.1 to 15% by weight.

[0010] Titanium oxide is resonated and excited by external light energy, particularly electromagnetic waves in the ultraviolet region, creates a strong oxidizing power and reliably sterilizes general bacteria over a wide area. However, if it is less than 9 % by weight, the bactericidal property is remarkably reduced, and if it exceeds 30 % by weight, a remarkable bactericidal effect cannot be obtained. Silver or copper can continuously exert an oligodynamic action which is an antibacterial action. Silver or copper is physically attached to the mixture as silver or copper molecules by firing,
This is because there is no elution of silver ions or copper ions. However,
Silver or copper exerts an antibacterial action even at about 1 ppm, but if it exceeds 1% by weight, the organic compound may be deteriorated.

[0011]

FIG. 1 is a sectional view of an antibacterial coated metal plate according to the present invention. Reference numeral 1 denotes a metal plate, and reference numeral 2 denotes an antibacterial coating film applied and baked on the surface of the metal plate 1. As the metal plate 1, a steel plate, a galvanized steel plate, a zinc-aluminum alloy-plated steel plate, a stainless steel plate, a tin-plated steel plate, an aluminum plate, or the like is used. On the surface of the metal plate 1, an antibacterial coating 2
Before painting, a surface treatment such as chromate treatment is performed in advance.

Instead of coating and baking the antibacterial coating 2 directly on the surface of the metal plate 1, an undercoat layer 3 is formed on the surface of the metal plate 1 as shown in FIG. The antibacterial coating film 2 may be painted and baked on the surface. In this case, a polyester-based or epoxy-based resin paint is used as the undercoat coating layer 3. If rust prevention is required, strontium chromate 5-
60 parts by weight, or calcium chromate or barium chromate is used in combination. The baking temperature of the undercoat layer 3 is set to 170 to 260 ° C. in order to enhance workability and weather resistance, and the thickness of the undercoat layer 3 is set to 0.5 to 20 μm.

The antibacterial coating film 2 is formed by blending an antibacterial agent with a resin paint, and the resin paint uses an acrylic resin, a polyester resin, a fluorine resin, or the like. It is preferable that the baking temperature of the resin paint is 170 to 260 ° C. and the baking time is 10 to 200 seconds, since the crosslinking becomes longer and the workability and weather resistance can be improved.

The antibacterial agent is manufactured by baking at 700 to 900 ° C. to have an average particle size of 1 μm or less. As a result, the surface area ratio is much larger than that of a conventionally used antibacterial agent having an average particle diameter of 10 μm or more, and high-efficiency radiation of electromagnetic waves in the infrared region from the antibacterial agent component becomes possible. The average particle size of each composition of the antibacterial agent is about 0.01 to 0.3 μm.

As described above, an undercoating film layer is formed on the surface of the metal plate 1 and the antibacterial coating film 2 is applied and baked thereon. It is optional to form a layer and paint-bake the antibacterial coating 2 on this intermediate coating layer. Of which, a printing layer is formed on an undercoating layer or an intermediate coating layer, or between an undercoating layer and an intermediate coating layer, or between an undercoating layer and an antibacterial coating, or between an intermediate coating and an antibacterial coating. Forming is optional. Further, it is optional to use the undercoating layer, the intermediate coating layer or the antibacterial coating 2 as a colored layer or a clear layer. The antibacterial coating film 2 is formed on both sides of the metal plate 1 as well as on one side.
Can be painted, baked and dried.

[0016]

【Example】

Examples 1 to 14 Galvanized steel sheets were subjected to chromate treatment, and then the following antibacterial agents and resin paints were baked and dried at the amount of the antibacterial agents shown in the table in FIG. The dry coating thickness is 15 μm. (1) Antibacterial agent (i) Antibacterial agent A 50% by weight of silicon carbide, 30% by weight of alumina oxide, 0.5% by weight of manganese oxide, 0.5% by weight of zinc oxide, 18.99% by weight of titanium oxide, and 0.1% of silver. With a composition of 01% by weight,
A fired body fired to an average particle size of 0.9 μm was used. (Ii) Antibacterial agent B: 60% by weight of silicon oxide, 20% by weight of alumina oxide, 5% by weight of manganese oxide, 5% by weight of zinc oxide, 9.9 of titanium oxide
% Of silver and 0.1% by weight of silver.
A fired body fired to μm was used. (2) Resin paint (i) Composition of polyester resin paint A 30.6% by weight of polyester resin, 39.6% by weight of solvent, 26.5% by weight of titanium oxide as a color pigment, 1.5% by weight of titanium yellow, silica 2.6% by weight of matting agent (ii) Composition of polyester resin-based coating material B 52.7% by weight of polyester resin, 21.8% by weight of solvent, 24.0% by weight of titanium oxide as a color pigment, 1.0% by weight of extender %, Silica-based matting agent 0.5% by weight (iii) Composition of urethane resin-based coating material 29.1% by weight of polyurethane resin, 29.1% by weight of solvent, 22.4% by weight of titanium oxide as a color pigment, 0.1% of titanium yellow. 3% by weight, trace amount of inorganic pigment black and blue (iv) Composition of vinylidene fluoride resin paint Resin 3 in a ratio of acrylic to vinylidene fluoride of 3: 7
6.7% by weight, solvent 50.0% by weight, coloring pigment titanium oxide 13.0% by weight, calcined pigment black 0.2% by weight, yellow 0.1% by weight, and a small amount of red

[0017]

[Comparative example]

Comparative Examples 1 to 10 As shown in the chart of FIG. 2, Comparative Examples 1 to 4 did not contain an antimicrobial agent, Comparative Examples 5 to 7 added a silver-containing zeolite-based antimicrobial agent, and Comparative Examples 8 to 10 Except that an imidazole organic antibacterial agent was added, the procedure was the same as in the above example.

Each of the coated steel sheets produced as described above was tested for antibacterial properties, workability, coating film hardness and corrosion resistance in the following manner.

(1) Antibacterial test An antibacterial test was performed for fungi, each of black mold, blue mold, and black yeast-like fungus, and for bacteria, each of Escherichia coli, Staphylococcus aureus, and Salmonella. Antibacterial test method, using a test bacteria cultured at 35 ° C. for 24 hours on a standard agar medium for each test bacteria,
Each of the test bacterial cells was adjusted to be 10 ⁶ to 10 ⁷ cells / ml to form a test bacterial solution, which was then filtered onto a filter paper.
2 ml was dropped and the filter paper was allowed to stand on each test piece.
4 hours, 48 hours, 120 hours, 144 hours,
At 168 hours, the filter paper left for each time is taken out, put in 9.8 ml of sterilized water, 0.1 ml is taken out, smeared and cultured, and the number of viable bacteria after culture (number / ml)
Was examined. (2) Workability test 18 test pieces were prepared according to the JIS G3312k bending test method.
Bend 0 degree, peel off the bent part with cellophane tape,
The state of peeling of the coating film was observed. (3) Hardness test of paint film The test was conducted according to the pencil hardness test method of JIS G3312.
The hardness of the hardest pencil that did not damage the coating film was defined as the coating film hardness. (4) Corrosion resistance test The corrosion resistance test was carried out according to the salt spray test method of JIS G3212.

Test Results (1) Antibacterial Test The results of the antibacterial test are shown in FIG. In the charts, ◎ indicates that the viable cell count is 10 ⁴ / ml or less, ○ indicates that the viable cell count is 10 ⁴ to 10 ⁵ / ml, and Δ indicates that the viable cell count is 10 ⁵ to 1.
0 ⁶ cells / ml, × mark viable count is 10 ⁶ cells / ml or more. As is clear from this chart, in the case of Comparative Examples 8 to 10 in which an imidazole-based organic antibacterial agent was added, mold had an antibacterial effect, but bacteria had a low antibacterial effect, and a silver-containing zeolite-based In Comparative Examples 5 to 7 to which an antimicrobial agent was added, the number of bacteria was reduced only to about 10 ⁶ to 10 ⁴ cells / ml, but in Examples 1 to 14, both mold and bacteria, as time passed, It turns out that there is an effect of reducing the number of bacteria more than the silver-containing zeolite antibacterial agent. (2) Workability test The results of the workability test were not different from those of the conventional coated metal plate without an antibacterial agent, and the workability was secured. Experimental example Polyester A (bent part 3T) No peeling Polyester B (bent part 0T) No peeling Urethane (bent part 2T) No peeling Vinylidene fluoride (bending part 4T) No peeling (3) Hardness test The results of the film hardness test were not different from those of the conventional coated metal plate without the antibacterial agent, and the coating film hardness was secured. Experimental Example Polyester A 3H Polyester B H Urethane 2H Vinylidene fluoride F (4) Corrosion resistance test The results of the corrosion resistance test were not different from those of the conventional coated metal plate without an antibacterial agent, and the corrosion resistance was secured. Experimental example Polyester A 500 hours No abnormalities Polyester B 250 hours No abnormalities Urethane 500 hours No abnormalities Vinylidene fluoride 2000 hours No abnormalities

[0021]

According to the antibacterial coated metal plate of the present invention, the antibacterial agent emits electromagnetic waves in the infrared region, and the water molecules in the bacteria that form general bacteria and the environmental water molecules essential for their propagation. Is caused to resonate and excite, thereby inhibiting the physiological function of the cells and effectively suppressing the growth of the cells. Further, since the average particle size of the antibacterial agent is 1 μm or less to increase the surface area ratio, the radiation efficiency of electromagnetic waves in the infrared region can be increased accordingly, and the propagation of bacteria can be more effectively suppressed. The antibacterial agent does not deteriorate even when painted on a metal plate and baked at a high temperature, and can improve workability and weather resistance. In particular, since titanium oxide is used, the sterilizing power can be increased. Furthermore, it is excellent in that an oligodynamic action, which is an antibacterial action of silver or copper, can be continuously exerted.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an antibacterial coated metal plate showing one embodiment.

FIG. 2 is a table showing Examples 1 to 14 and Comparative Examples 1 to 10.

FIG. 3 is a table showing the results of an antibacterial test.

FIG. 4 is a cross-sectional view of an antibacterial coated metal plate showing another embodiment.

[Explanation of symbols]

 1 Metal plate 2 Antibacterial coating 3 Undercoat coating

Claims (3)

(57) [Claims] 1. The method according to claim 1, wherein the solid content of the resin coating is 10% on the surface of the metal plate.
After the antibacterial coating film in which 0.05 to 50 parts by weight of the powdered antibacterial agent is blended with respect to 0 parts by weight is applied, the sheet temperature is 170 to 26.
An antibacterial coated metal plate baked and dried at 0 ° C., wherein the antibacterial agent has an average particle size of 1 μm or less, 30 to 80% by weight of silicon carbide or silicon oxide, and 9 to 40% by weight of alumina oxide. %, Manganese oxide is 0.1 to 15% by weight,
0.1 to 15% by weight of zinc oxide, 9 to 30 of titanium oxide
An antibacterial coated metal sheet, characterized in that the metal sheet is fired at a ratio of 1% by weight or less by weight of silver or copper. 2. The antibacterial coated metal sheet according to claim 1, wherein an undercoating layer is formed on the surface of the metal plate, and the antibacterial coating is baked on the undercoating layer. 3. The antibacterial coated metal plate according to claim 1, wherein the antibacterial coating film is baked on both surfaces of the metal plate.