JPH09195647A - Antifouling screen net - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a screen net excellent in safety and durability without requiring a special device, treatment, etc., free from maintenance, showing a high antifouling property and capable of maintaining sufficient cleanliness only by natural cleaning by rain and simple water cleaning. SOLUTION: This screen net is constituted by coating a semiconductor thin film showing photocatalystic action or a thin film 2 containing semiconductor particulates showing the photocatalystic action on a wire rod 1. Or additionally, an antibacterial metal or an antibacterial metal alloy 5 is deposited on the thin film. It is possible to decompose soil of fat and oil, etc., to prevent attachment of soil of diesel dust, tire dust, carbon particulates, etc., hard to remove, to prevent growth of mold and to maintain sufficient cleanliness by natural cleaning by rain and simple cleaning of waterwashing, etc., by applying the aforementioned treatment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antifouling screen door net having a function of decomposing an organic substance, and more specifically, coating a semiconductor thin film having a photocatalytic action or a thin film containing semiconductor fine particles, or further the above thin film. Antibacterial metal or antibacterial metal compound deposited on top
A screen door net with excellent anti-mold and anti-fouling properties.

[0002]

2. Description of the Related Art Mosquitoes, flies, etc. flying to houses, buildings, factories, etc.
The screen door net, which is widely used to prevent insect damage such as cockroaches, attaches to various stains because it is installed outdoors for a long time. The dirt contains components such as earth and sand that are easily removed with water, and components that are difficult to remove with water, such as oil and fat. If only dirt components such as earth and sand adhere, it can be removed by natural washing with rain or water washing, but usually because it is in a mixed state with oil and fat components,
It is difficult to remove only by washing with water. Further, once components such as fats and oils adhere, stain components that are difficult to remove even if detergent such as diesel dust, tire dust, and carbon particles are used are easily adsorbed on the components, and the stains increase.

Although detergents for screen door nets are commercially available,
In the case of a screen door net, its mechanical strength and attachment strength are low, so if it is strongly rubbed it will cause deformation and drop off from the net's fixed frame, making it difficult to completely remove dirt, which reduces the aesthetics of the building. It's a big problem. In addition, the resin screen door net has a problem that a mold grows on the net, which may cause darkening stains, which is not only hygienic but also aesthetically unfavorable. Further, once the mold has grown, it is difficult to remove it, and there is a method of removing it using a chemical such as a mildew treating agent, but it is not easy to remove the mold with chemicals due to problems such as safety of chemicals and odor.

By the way, it has been conventionally known that a semiconductor having a photocatalytic action represented by TiO ₂ has antibacterial, antifungal, antifouling and deodorant actions due to the photocatalytic action, and recently, by utilizing them. , Various materials in which bacteria and mold are hard to reproduce are being researched and developed. For example, Japanese Unexamined Patent Publication (Kokai) No. 2-6333 discloses an antibacterial powder in which antibacterial metal such as copper and zinc is supported on the surface of titanium oxide particles, and this powder should be blended with resin, rubber, glass and the like. An antibacterial composition can be obtained by a known method, and as well as an antibacterial treatment of electric appliances, furniture furniture, upholstery materials, packaging materials such as foods, etc., as an antibacterial agent for environmental hygiene facilities and equipment. It teaches that the above powders can be utilized.

In Japanese Patent Laid-Open No. 6-65012, a titanium oxide film containing a metal such as silver, copper, zinc or platinum is coated on a substrate made of a material such as concrete, glass, plastic, ceramics or metal. It is disclosed that the substrate can prevent the propagation of germs and mold. Further, in Japanese Patent Laid-Open No. 7-51646, solid particles are supported on a solid surface of glass or the like, which may be contaminated by adhesion of organic substances in the air, and irradiated with light containing ultraviolet rays to stain the solid surface. It teaches that it can purify and prevent the adhesion of dirt. However, there is no known example in which such a semiconductor having a photocatalytic action is used for imparting antifouling property to a screen net.

[0006]

As described above, it is difficult to easily remove the dirt adhering to the screen door net, and the cleaning requires a great deal of labor and cost under the present circumstances. Therefore, the object of the present invention is to be excellent in safety and durability without requiring special equipment, treatment, etc., maintenance-free, shows high antifouling property, and can be naturally washed by rain or simply washed with water. The purpose is to provide a screen net that can maintain sufficient cleanliness.

[0007]

In order to achieve the above object, according to the present invention, antibacterial and antibacterial agents are formed on the wire rod surface of a screen net made of a polymer material such as polypropylene or vinyl chloride resin or a metal material such as stainless steel. Provided is an antifouling screen net, which is characterized by being coated with a semiconductor thin film or a thin film containing semiconductor fine particles having a photocatalytic action exhibiting antifungal properties. Further, according to the present invention, the wire surface of the screen net made of a polymeric material, a barrier layer for blocking the photocatalytic action, and the photocatalytic action exhibiting antibacterial and antifungal properties by decomposing the organic substance under irradiation of light. There is provided an antifouling screen door net, which is characterized in that the semiconductor thin film or the thin film containing semiconductor fine particles is sequentially coated. In a preferred embodiment, silver, antibacterial metal such as copper, or an antibacterial metal compound such as copper is further deposited on the thin film containing the semiconductor thin film or semiconductor fine particles having a photocatalytic action to further improve antibacterial / mold / antifungal properties. A screen net with excellent stain resistance is provided.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION As a basic aspect of the present invention, a semiconductor thin film having a photocatalytic action is formed on a wire rod surface of a screen net made of a polymer material such as polypropylene or vinyl chloride resin or a metal material such as stainless steel. The present invention provides a screen net formed with a thin film containing semiconductor fine particles (hereinafter collectively referred to as a photocatalytic film). A semiconductor having a photocatalytic action, for example, TiO ₂ is present on the surface of the wire of such a screen door net. When this semiconductor is irradiated with sunlight or fluorescent light, holes (h) are formed on the TiO ₂ surface.
⁺ ) And electrons (e ⁻ ) are generated to show a photocatalytic action, and water and various organic substances are decomposed. Further, water is oxidized OH radicals by the action of the hole, also, by the action of electrons is oxygen in the air reducing O ₂ ^- generated radicals. These active oxygens have an excellent bactericidal action, and as a result, mildew and the like are less likely to occur.

When the screen door net is installed outdoors, the organic substance is decomposed by the action of the photocatalytic film when irradiated with light during the day. That is, even if components such as earth and sand that are easily removed with water and components that are difficult to remove with water such as fats and oils are mixed and adhered, by decomposing these fats and oils, they can be removed by natural washing with rainwater or washing with water. Only possible dirt will be on the screen door net. Further, it is possible to reduce dirt itself by preventing adsorption of dirt substances that are easily adsorbed by components such as fats and oils and difficult to remove, for example, diesel dust, tire dust, carbon particles and the like.

When metal ions are present on the surface of a semiconductor such as TiO ₂ , various metal ions are reduced by the action of electrons generated by light irradiation. That is, it becomes possible to deposit an antibacterial metal such as silver or copper or a compound containing an antibacterial metal. By utilizing this to deposit an antibacterial metal or an antibacterial metal compound on the photocatalyst film, the antibacterial and antifungal properties can be maintained even at night.

As the semiconductor used in the photocatalytic film formed on the surface of the wire of the screen net, any semiconductor having a relatively high electron-hole mobility and a photocatalytic action can be used, for example, TiO 2. ₂ , SrTiO
₃ , ZnO, CdS, SnO _{2 and the} like can be mentioned, and among these, TiO ₂ is particularly preferable.

Various methods such as a sputtering method, a thermal spraying method, a laser ablation method, a sol-gel method, and a plating method can be used as a method for coating such a semiconductor having a photocatalytic action. Alternatively, the semiconductor fine particles may be dispersed in a suitable coating material, and the coating material may be applied to the base material and dried to apply the coating. When the screen net wire is made of a metal material such as stainless steel and can withstand high temperatures, the photocatalytic film can be formed by the various coating methods described above. On the other hand, when the screen door wire is made of a resin material such as polypropylene or vinyl chloride resin, it cannot be heated because its heat resistance is poor. In that case, it is preferable to disperse the semiconductor fine particles in a suitable coating material and apply the coating material to a base material and dry the base material for coating.

When the screen door wire is made of a resin material such as polypropylene or vinyl chloride resin, if the photocatalytic film is directly coated on the wire, the resin material itself is decomposed by the photocatalytic action and the photocatalytic film is peeled off. At the same time, the mechanical properties such as strength of the screen door net are deteriorated. In such a case, a method of coating the photocatalytic film after coating a layer for blocking the photocatalytic action (hereinafter referred to as a barrier layer) on the screen net is preferable. As the barrier layer, a coating material containing no semiconductor fine particles exhibiting a photocatalytic action can be applied. By providing such a barrier layer, decomposition of the resin material itself of the screen door wire can be prevented, and mechanical properties such as strength and flexibility of the resin material can be maintained without being deteriorated. The effect of further improving the adhesion can be obtained when a coating in which semiconductor particles are dispersed (particularly the same coating as the barrier layer) is coated as a film.

The film thickness of the photocatalyst film coated on the screen door net is the same whether the photocatalyst film is coated or the barrier layer and the photocatalyst film are coated.
10 nm to 10 μm is suitable. When the film thickness exceeds 10 μm, the photocatalyst film easily peels off from the surface of the substrate, which is not preferable. In particular, after coating the photocatalyst film, peeling easily occurs during processing such as cutting and during construction. Further, when the barrier layer is provided, the film thickness thereof needs to be 5 nm or more so as to cover the entire surface of the screen door wire rod and to block the photocatalytic action of the coated photocatalytic film. The total thickness of the barrier layer and the photocatalyst film is preferably 10 μm or less for the same reason as above.

Examples of the paint used for coating the photocatalyst film containing the semiconductor fine particles or the paint used for forming the barrier layer include fluorine-based, silicate-based, acrylic-based, polyester-based, polyurethane-based and the like. Is uniformly dispersed and has appropriate strength and adhesiveness as a coating film on a screen net wire rod, and is not particularly limited, and can be appropriately selected according to the application. In addition, among the above-mentioned paints, inorganic paints such as fluorine-based paints and silicate-based paints are more preferable in view of their oxidation resistance.

In the case of a coating method in which semiconductor fine particles are dispersed in a paint and applied, the proportion of the semiconductor fine particles to be mixed is 1 to 100% by weight (here 100% by weight is the semiconductor fine particles). Is equivalent to the weight of the paint base material). If it is less than 1% by weight, the amount of semiconductor fine particles exerting a photocatalytic action is insufficient, and thus a sufficient photocatalytic action cannot be obtained. On the other hand, if it exceeds 100% by weight, there is no problem in exhibiting a photocatalytic action, The mechanical properties of the membrane are significantly reduced.

The particle size of the semiconductor fine particles used is from 5 nm to
1 μm, preferably 10 nm to 300 nm is suitable. If the particle size is smaller than 5 nm, the bandgap becomes large due to the quantum size effect, and there is a problem that the photocatalytic action cannot be obtained unless under illumination such as a low-pressure mercury lamp that emits short-wavelength light. In addition, if the particle size is too small, handling may be difficult or the dispersibility may be deteriorated. 10 nm from the point of handling
The above particle size is preferable. On the other hand, if the particle size exceeds 1 μm, relatively large semiconductor fine particles are present on the material surface, the surface becomes poor in smoothness, and the particles exposed on the material surface are likely to fall off. Considering the smoothness of the material surface and the like, a particle size of 300 nm or less is preferable.

The method of depositing the antibacterial metal or the antibacterial metal compound on the photocatalyst film is to prepare a solution of an appropriate compound containing an antibacterial metal such as silver or copper such as silver nitrate or copper chloride,
As one method, a screen door net coated with a photocatalytic film is dipped in the solution and irradiated with ultraviolet rays by an ultraviolet lamp or a black light, whereby antibacterial metal ions or antibacterial metal compound ions are generated by electrons generated by photocatalysis. It is reduced and an antibacterial metal or an antibacterial metal compound is deposited on the surface of the screen door net. In this case, the amount of the antibacterial metal or the antibacterial metal compound deposited depends on the amount of the antibacterial metal ion in the solution, that is, the concentration of the prepared solution, the concentration of the reducing agent such as alcohol or EDTA added to the solution, or the ultraviolet irradiation. Control by time.

Further, as another method, there is a method in which the solution is applied onto a screen net coated with a photocatalyst film by an appropriate method such as spraying, and then the solution is irradiated with ultraviolet rays.
In this method, the antibacterial metal or antibacterial metal is adjusted depending on the amount of the antibacterial metal ion in the solution, that is, the concentration of the prepared solution, the concentration of the reducing agent such as alcohol or EDTA added to the solution, the coating amount, or the ultraviolet irradiation time. The amount of compound deposited can be controlled. In any of the above methods,
If the entire surface of the photocatalyst film is coated with the antibacterial metal or the antibacterial metal compound, the photocatalytic action cannot be exhibited, so it is necessary to control the deposition amount to the extent that the entire surface is not covered.

By the method as described above, a screen net coated with a photocatalyst film as shown in FIGS. 1 to 3 is produced. FIG. 1 shows a case in which a photocatalyst film 2 is directly coated on a metal mesh door net wire 1 made of stainless steel or the like, and FIG. 2 shows a resin mesh door net wire 3 made of polypropylene or vinyl chloride resin coated with a barrier layer 4. Then, the photocatalyst film 2 is coated thereon. In addition, FIG. 3 shows an antibacterial metal or an antibacterial metal compound 5 deposited on the surface of the photocatalyst film 2 of the embodiment shown in FIG.

When a screen door net made of a wire material coated with a photocatalyst film as described above or a wire net made of a wire material coated with an antibacterial metal or an antibacterial metal compound after being coated with a photocatalyst film is used, As shown in FIG. 4, a frame 8 made of aluminum or an aluminum alloy is manufactured, and a screen door net coated with a photocatalyst film or an antibacterial metal or an antibacterial metal compound is deposited after coating the photocatalyst film. The screen door 6 is constructed by attaching the screen screen 7 which is attached. In addition, frame 8
Also, a frame material coated with a photocatalyst film or a frame material having an antibacterial metal or an antibacterial metal compound deposited thereon according to the present invention can be used.

The screen door unit according to the present invention having the above-mentioned structure is installed outdoors and is irradiated with light during the daytime, and therefore exhibits a function of decomposing an organic substance by a photocatalytic effect. That is, even if components that are easily removed with water, such as earth and sand, and components that are difficult to remove with water, such as fats and oils, are mixed and adhered,
By decomposing this oil and fat component, only dirt that can be removed by rainwater natural washing or water washing will be present on the screen net. Also, since the fat and oil components decrease,
It is possible to reduce the amount of adhering dirt substances, such as diesel dust, tire dust, and carbon particles, which are difficult to remove, to reduce the amount of dirt. Furthermore, due to the antibacterial and antifungal properties due to the photocatalytic action, it is possible to prevent stains caused by bacteria and fungi.

In addition, when a screen net made of a wire rod coated with an antibacterial metal or an antibacterial metal compound after coating the photocatalytic film is used, it may occur when the light irradiation amount is small or at night. However, due to the antibacterial and antifungal properties due to the action of the antibacterial metal or the antibacterial metal compound, it is possible to prevent stains caused by bacteria and fungi.

[0024]

EXAMPLES Hereinafter, the effects of the present invention will be specifically described with reference to examples and comparative examples. However, it goes without saying that the present invention is not limited to the following examples.

Example 1 A screen net made by weaving stainless wire rods having a diameter of 0.3 mm at 1 mm intervals was used, and TiO ₂ having an average particle size of 20 nm was immersed in water.
Was coated with a sol having 35 wt% dispersed therein, and the mixture was heated and sintered at 500 ° C. for 1 hour to coat the screen wire net material with a photocatalytic film having a thickness of 2 μm.

Comparative Example 1 For comparison, a stainless screen door net not coated with a photocatalytic film was used.

Evaluation of Antifouling Property: In order to determine the antifouling property of each screen net of Example 1 and Comparative Example 1, the outdoor net was exposed for 1 year and the weight change was measured. Table 1 shows the results.
In addition, after the outdoor exposure, each screen net of Example 1 and Comparative Example 1 was allowed to stand in pure water for 1 hour, and the weight change of the dirt substance adhering to the screen net before and after that was measured. Table 2 shows the results.

[Table 1]

[0028]

[Table 2]

From the results shown in Table 1, it can be seen that the weight increase amount of the screen net of Example 1 is smaller than that of Comparative Example 1. Further, from the results shown in Table 2, it is understood that the weight reduction of the screen door net of Example 1 is larger than that of Comparative Example 1, and most of the attached stain components can be washed with water in the screen door net of Example 1. . Example 1 has a photocatalyst film coated on the surface of a screen net, and exhibits an action of decomposing an organic substance under light irradiation. That is, the first embodiment
In the screen net of Diesel dust, tire dust, dirt particles such as carbon particles are prevented from adhering, and since water washable components and fats and oils components are not mixed, even if components such as earth and sand adhere Removed by washing with rain,
The weight increase is reduced. Also, it can be confirmed from Table 2 that the attached dirt can be removed by simple water washing. On the other hand, in the screen door net of Comparative Example 1, since oil and fat components are not decomposed, diesel dust, tire dust,
Since carbon particles and the like are easily attached and the components such as earth and sand and the oil and fat components are mixed, it is difficult to remove them by rain, and the weight increase is larger than that of the screen door net of Example 1, and Table 2 From the above, it is understood that it is difficult to remove the adhered dirt only by washing with water. From the above, it can be seen that the screen door net coated with the photocatalytic film according to the present invention exhibits good antifouling property.

Example 2 A vinyl chloride resin wire rod having a diameter of 0.3 mm was woven at 1 mm intervals on a screen net, coated with 2 μm of a silicone resin, and further coated with T having an average particle diameter of 20 nm.
A silicone resin containing 35% by weight of iO ₂ dispersed in a solid component was coated to a thickness of 2 μm (Sample 1). further,
Sample 1 was immersed in a 0.05 mol / liter copper chloride aqueous solution and irradiated with ultraviolet rays from a 100 W ultraviolet lamp to deposit 0.05 mg / cm ² of copper on the surface of the screen door wire (Sample 2).

Comparative Example 2 For comparison, a vinyl chloride resin mesh door net not coated with a photocatalytic film was used.

Antifungal test: For each of the screen door nets of Samples 1 and 2 and Comparative Example 2, the antifungal test was carried out based on the antifungal test of general industrial products described in JIS Z 2911-5. Moreover, in order to observe the difference in the antifungal property depending on the presence or absence of light irradiation, each sample was measured at a distance of 20 cm from
The mildew-proof property was measured for the case where light was irradiated with a W fluorescent lamp and the case where light was not irradiated at all. Table 3 shows the results.
In addition, according to JIS Z2911, the judgment in Table 3 shows that no hyphal growth was observed in the part inoculated with mold by 3 on the surface of the screen door net wire, and 2 was the area of fungal growth in the mold inoculated area. No. 1/3 of the above, and 1 is the one in which the area of the developing part of the hypha exceeds 1/3 of the fungal inoculation area, and is shown in a three-level evaluation.

[Table 3]

From the results shown in Table 3, only the sample 2 shows good antifungal property in the state without light irradiation, and both the sample 1 and the sample 2 show good antifungal property under the light irradiation. Recognize. On the other hand, it can be seen that Comparative Example 2 has no antifungal property both in the dark and in the light irradiation. That is, the sample 1 coated with only the photocatalytic film exhibits antibacterial and antifungal properties due to the photocatalytic action only under the light irradiation, but the sample 2 further having the antibacterial metal deposited has the photocatalytic film formed under the light irradiation. It can be confirmed that the photocatalytic action, the action of the antibacterial metal, and the action of the antibacterial metal exhibit good antibacterial and antifungal properties in the absence of light irradiation. From the above, it was confirmed that the sample coated with the photocatalyst film and further deposited with the antibacterial metal showed good antifungal property both in the dark and under the light irradiation.

[0034]

As described above, the screen door net of the present invention is
Since the photocatalytic film is coated on the screen door wire, it has excellent antibacterial, antifungal and antifouling properties. Therefore, according to the present invention, there is provided a screen door net which is excellent in safety and durability, is maintenance-free, and has high antifouling property, without requiring a special device or treatment. Further, even if dirt is attached, a screen door net capable of maintaining sufficient cleanliness only by natural washing with rain or simple washing with water is provided. In addition, in the screen door net of a mode in which a barrier layer for blocking the photocatalytic action is coated on the screen door net wire, and then the photocatalytic film is coated, in the case of using a resin material for the wire rod of the screen door net, Decomposition is prevented, and mechanical properties such as strength and flexibility of the resin material can be maintained without deterioration. Further, there is an advantage that the adhesiveness of the photocatalyst film, particularly the adhesiveness when the paint in which the semiconductor fine particles are dispersed is coated as the photocatalyst film is further improved. Furthermore, if the antibacterial metal or antibacterial metal compound is deposited on the photocatalyst film by the reducing action of this photocatalyst film, it shows excellent antibacterial and antifungal properties even in the absence of light irradiation, and prevents stains due to mold. Thus, a screen door net exhibiting further excellent antifouling property is provided by the synergistic effect of the antibacterial metal or the antibacterial metal compound and the photocatalyst film under irradiation of light.

[Brief description of the drawings]

FIG. 1 is a schematic enlarged cross-sectional view of a wire rod of a metal screen net coated with a photocatalytic film.

FIG. 2 is a schematic enlarged sectional view of a wire rod of a resin screen door net coated with a photocatalyst film.

FIG. 3 is a schematic enlarged cross-sectional view of a wire material of a photocatalytic film-coated screen door net onto which an antibacterial metal or an antibacterial metal compound is deposited.

FIG. 4 is a schematic plan view of an antifouling screen door incorporating the screen door net according to the present invention.

[Explanation of symbols]

 1 metal screen door wire 2 photocatalyst film 3 resin screen door wire 4 barrier layer 5 antibacterial metal or antibacterial metal compound 6 screen 7 screen screen 8 frame

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuhito Hashimoto 2073-2, Iijimacho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture New City Hongodai D Bldg. 213 (72) Inventor Nobuyuki Nakata 1300 Horikiri, Kurobe-shi, Toyama Prefecture (72) Inventor Arai Toshio 841 Fujiki, Toyama City, Toyama Prefecture

Claims (3)

[Claims] 1. An antifouling screen door net, characterized in that the wire rod surface of a screen net made of a polymer material or a metal material is coated with a semiconductor thin film having photocatalytic activity or a thin film containing semiconductor fine particles. 2. A wire layer of a screen net made of a polymer material, a barrier layer for blocking photocatalytic action, and a semiconductor thin film or a thin film containing semiconductor fine particles having photocatalytic action for decomposing an organic substance under light irradiation are sequentially formed. Antifouling screen door net characterized by being coated. 3. The antifouling agent according to claim 1 or 2, wherein an antibacterial metal or an antibacterial metal compound is further deposited on the photocatalytic semiconductor thin film or thin film containing semiconductor fine particles. Sex screen door net.