JPH10185257A - Ventilating fan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ventilating fan with a function for removing or detoxifying organic matter such as greasy stains and germs or organic gases such as formaldehyde by decomposition or oxidation. SOLUTION: A ventilating fan 1 having a plurality of vanes 2 is provided with a surface layer including anatase type TiO2 at least on the surface of the base material of each vane 2. The surface layer of anatase type TiO2 acts to decompose stains of organic matter, such as greasy matter and nicotine from tobacco, which attaches to the surface and to destroy germs attaching to the surface so that the surface can be kept clean. Furthermore, the indoor concentrations of organic gases, such as formaldehyde emitted from the floor or walls, are lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ventilation fan installed in a window or a wall of a building and used to exchange air in a room.

[0002]

Generally, a ventilation fan has a shape having three to four blades around a central axis, and by rotating the blades by a motor provided on the central axis, a room is provided. It is configured to send out the air inside to the outside. Further, those provided with blinds to cover when not in use are also widely used. As described above, since the ventilation fan sends out the dirty air in the room, dirt such as oil stains and cigarette dust easily adhere to the surfaces of the blades and blinds, but the complicated shape makes cleaning difficult and time-consuming. . In addition, since the installation place is relatively high in many places, cleaning is also difficult from this point. Unless cleaning is performed regularly, molds (microorganisms such as bacteria and mold spores) adhere to the soil, which is not preferable in terms of hygiene.

On the other hand, floors and wall coverings are used in the interior of a building, and are used as an adhesive as a component constituting them or as an adhesive for attaching these flooring or wall coverings to a base. Although urea resin, phenol resin and the like which are inexpensive and have high adhesive strength are often used, this adhesive has the property of releasing formaldehyde contained in the resin into the air. In addition, formaldehyde continues to be generated even after construction is completed, which is not preferable in terms of living environment. Therefore, a method of changing the adhesive to one that does not emit formaldehyde, such as a vinyl acetate emulsion, a resorcinol resin, and an epoxy resin, and a method of mixing a formaldehyde trapping agent in the adhesive have also been adopted, but in the former method, The price of the adhesive used is higher than that of urea / formalin-based adhesives.In addition, the temporary adhesion is poor, and the number of non-defective products during production decreases. There is a drawback that the cost of the adhesive is high to use, and the adhesive properties will change depending on the combination with the adhesive,
In reality, it is often necessary to use one that emits formaldehyde. Examples of other organic gases that easily fill the room include plasticizers such as tricresyl phosphate and dioctyl phthalate, and organic solvents such as toluene and xylene.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention removes organic substances such as oil stains, fungi, and organic gases such as formaldehyde by decomposing or oxidizing them in a ventilation fan to render them harmless. It has a function. That is, it has a function of decomposing organic dirt such as oily dirt, so that dirt can be naturally removed or easily wiped off, or a function of sterilizing attached fungi can be imparted, or an organic dirt such as formaldehyde can be provided. The function of suppressing the filling of the gas into the room is provided to reduce the concentration of formaldehyde radiated from the floor and walls and floating in the room.

[0005] During the exhaust operation of the ventilation fan, the organic gas is removed outdoors by the exhaust operation, so that the decomposition operation of the organic gas by the ventilation fan itself has little effect. However, even if it is a ventilation fan, it cannot always be in operation, and there is always time to suspend. During this pause, the action of decomposing organic gas by the ventilation fan itself is effective.

[0006]

FIG. 1 shows an example of a typical ventilation fan. In the figure, reference numeral 2 denotes a blade of the ventilation fan 1, and reference numeral 3 denotes a center axis to which each blade 2 is attached and rotated by a motor. Reference numeral 4 denotes a frame for attaching a ventilation fan to a window or a wall hole. The ventilation fan 1 of the type shown in FIG. 2 has four tilting plates 5 installed in parallel, each tilting plate 5 has a support shaft 6 at the upper end of both ends thereof, and is supported by operating a string or the like. It is tilted about the shaft 6 and is closed when the ventilation fan is not used. FIG. 3 is a cross-sectional view of the blade 2 used for the ventilation fan 1 as described above. In the present invention, a surface layer 11 containing anatase TiO ₂ is provided on the surface of a base material 10 constituting the blade 2.

Anatase TiO ₂ (titanium dioxide)
Is also referred to as “anonymous stone”, and its crystal system is a tetragonal system. This is one of a plurality of TiO ₂ crystal systems, and in particular, those crystal systems are remarkably decomposed or oxidized by organic matter such as oil stains, fungi, and formaldehyde by photoexcitation. The mechanism of the organic matter decomposition is considered as follows. That is, light (3 for pure TiO ₂ )
Wavelength of 80 nm or less. However, if a spectral sensitizer is added, even at longer wavelengths, the electrons in the valence band in the energy band are excited by the conductor and create electron-hole pairs. Of the pair created, electrons first reduce oxygen molecules O ₂ on the crystal surface to generate chemically active oxygen species, oxygen ions, etc., and holes oxidize water molecules on the crystal surface. To produce hydroxyl radicals and hydrogen ions. It is considered that organic substances in contact with them are oxidized (or reduced) by the action of chemically active hydroxyl radicals and the like generated in this way to decompose or convert them to another substance. For example, in the case of formaldehyde, it is converted by oxidation into formic acid, and further into water and carbon dioxide. Iron (III) oxide can also be added in order for such electron-hole pairs to efficiently generate hydroxyl radicals and active oxygen species on the crystal surface. The upper limit (absorption edge) of the photosensitive wavelength band of anatase TiO ₂ itself is 38.
Although it is 0 nm, a spectral sensitizer can be added to extend the wavelength to a longer wavelength side. A dye that absorbs visible light is used as such a spectral sensitizer. A typical example is a ruthenium complex such as Ru (4,4′-dicarboxyl-2,2′bipyridine) ₂ (NCS) ₂ .

The base material of the blade 2 is made of a metal such as iron, aluminum, copper, or titanium, an inorganic material such as ceramics, or an organic material such as a plastic plate such as polyvinyl chloride, acrylic, nylon, polypropylene, or ABS. Either can be used. If necessary, the surface of the blade substrate may be provided with a base coat or a pattern print. When an inorganic material is used, as shown in FIG. 3, the surface layer 11 containing anatase TiO ₂ may be formed directly on the surface of the base material 10, but when an organic material is used or the inorganic material is used. When a coating layer or a printed layer of an organic material is present on the surface even when used, as shown in FIG. 4, it is necessary to interpose a barrier layer 12 made of a resin or an inorganic material that does not react with anatase TiO _2. is there. Examples of the resin of the barrier layer 12 include fluorine resins such as polyvinylidene fluoride and polytetrafluoroethylene, and silicon resins such as polysiloxane, silicon rubber, and silicon acrylate. ₂ , metal oxides such as Al ₂ O ₃ , hafnium oxide, zinc oxide, tantalum oxide, aluminum,
There are metals such as chromium, nickel, brass, copper, and ceramics. The thickness of the barrier layer 12 is preferably 10 nm or more.

To form the surface layer 11 containing anatase TiO ₂ , a vacuum deposition method, a sputtering method,
A method may be used. Alternatively, a method of applying a titania sol using water, alcohol, or the like as a solvent, heating and drying and curing, or a method of adding heated steam to titanium tetrachloride or titanium fluoride, or a method of hydrolyzing a titanate aqueous solution Can also be used. Considering a sufficient decomposition or oxidation effect of organic substances, the thickness of the surface layer 11 containing anatase TiO ₂ is preferably 50 nm or more.

In the case where anatase-type TiO ₂ is dispersed in a resin binder to form a coating solution, one that does not absorb light in a wavelength band that excites TiO ₂ is selected. In order to prevent decomposition, special measures are required. Specifically, a material that does not contain (or contains only a small amount of) an organic material such as polysiloxane, or a resin that does not react with anatase TiO ₂ , such as the above-mentioned silicon resin or fluorine resin, is used as the binder. Alternatively, another effective means, as anatase TiO ₂ dispersed in a binder, the anatase type TiO ₂ in the pores of the inorganic transparent porous body used that were supported. Since anatase-type TiO ₂ has catalytic activity with near-ultraviolet light having a wavelength of 380 nm or less, an inorganic transparent porous material that transmits near-ultraviolet light having a wavelength of 380 nm or less is used. However, when a spectral sensitizer is added,
Select one that is transparent for wavelengths below the extended photosensitive wavelength upper limit (absorption edge).

[0011] Specific examples of the inorganic transparent porous material include zeolite, silica gel, silica alumina, cement, tricalcium silicate, calcium silicate, and the like.
Examples thereof include porous glass, aluminum hydroxide, and magnesium carbonate. Among these, it is preferable to use silica gel or zeolite from the viewpoints of the suitability for supporting the photocatalyst and the adsorptivity of the product decomposed by the photocatalyst.

The method for supporting a photocatalyst on these inorganic transparent porous bodies and the specific form of the photocatalyst carrier supporting the photocatalyst are not particularly limited. However, in order to obtain a sufficient photocatalytic function, It is preferable to support 10 to 900 parts by weight of a photocatalyst per 100 parts by weight of the inorganic transparent porous body. In order to further impart an antibacterial effect to the photocatalyst carrier, Ag ions can be adsorbed or carried on the carrier.

In order to prevent the invasion of the base resin into the pores of the inorganic transparent porous body, while permitting the intrusion of the object to be decomposed and selectively decomposing it, the porous body must be made of a porous material. The diameter of pores appearing on the surface is preferably from 10 nm to 10 μm, and the specific surface area of the porous body is preferably from 10 to 400 m ² / g. The inorganic transparent porous body has an average particle size of 1
It is preferable to use one having a thickness of 100 μm.

The binder resin behaves as an aggregate due to the cohesive force exerted between the binder resin molecules. The resin, which is an organic substance, and the inorganic transparent porous body are not well adapted to each other. Since air may enter between the binder resin and the binder resin, the binder resin hardly penetrates into the pores of the inorganic transparent porous body, and the binder resin can be prevented from being decomposed by contact with the photocatalyst. Further, even if the binder penetrates into the pores of the inorganic transparent porous body, the binder is not decomposed unless a photocatalyst is present therein, and even if the binder resin penetrated into the pores is decomposed by the photocatalyst, Only the nearby binder resin is locally decomposed,
The action of the photocatalyst does not reach the entire binder resin, and the photocatalytic function is not lost due to the falling off of the photocatalyst carrier.

On the other hand, most of the above-mentioned decomposed substances (contaminants) are usually diffused into the air in the form of molecules or colloids (aerosols), so that the pores of the porous material are easily diffused by the diffusion phenomenon. Penetrates and decomposes on contact with the photocatalyst. Therefore, since the photocatalyst is supported on the inorganic transparent porous body, the contact between the binder resin and the photocatalyst is avoided without impairing the photocatalytic function, the binder resin is not decomposed by the photocatalyst, and the photocatalyst is selected for a decomposition target. It is possible to make the photocatalyst act effectively.

In the ventilation fan of the present invention, inorganic dirt such as sand and mud is not generally decomposed, and organic dirt is not decomposed depending on the type and amount of the dirt and the amount of TiO _{2 on} the surface of the ventilation fan. In some cases, some may remain, or some residues of decomposition products may remain. In that case, a certain amount of wiping and cleaning is still required. However, in general, formation of a film of moisture on the surface of anatase TiO ₂ ,
Since the decomposition residue of the organic substance functions as a release layer, wiping and cleaning become easy, but inconvenience remains. In order to further reduce the inconvenience, in particular, in the case of a method in which anatase-type TiO ₂ particles are dispersed in a resin binder and applied, the above-mentioned fluororesin or silicon which is difficult to adhere to other substances as a binder is used. Use resin. Or,
A small amount (about 0.5 to 3% by weight) of an antistatic agent such as a surfactant is added to the resin binder so that the volume resistivity of the coating film becomes 10 ¹⁰ Ω · cm or less. This is preferable because dust, aerosol, and the like floating in the air are prevented from being adsorbed, and therefore, it is difficult to be stained from the beginning. Moreover, this is also effective for dust and the like that cannot be decomposed by anatase-type TiO ₂ . As the antistatic agent, anionic, cationic, nonionic surfactants are preferred because they have high transparency and hardly absorb TiO ₂ excitation light.
Examples of these surfactants include a polyoxyethylene alkyl phosphate ester-based surfactant, a naphthalenesulfonic acid formalin condensate, a special polycarboxylic acid-type polymer surfactant, a polyoxyethylene derivative, and oxyethylene / oxypropylene. Block copolymer, sorbitan fatty acid ester, polyoxyethylene fatty acid ester,
Examples include polyoxyethylene alkylamines, alkylalkanolamides, quaternary ammonium salts, pyridium salts, aminosulfates and the like.

The ink containing the anatase type TiO ₂ is coated with a printing method such as gravure offset printing or silk screen printing, or a coating method such as roll coating, flow coating, spray coating, or the like, to obtain the front, back, front and back surfaces of the substrate. Laminate on the front surface or the entire surface including both front and back surfaces and side surfaces.

In the ventilation fan of the present invention, a surface layer of anatase type TiO ₂ may be formed not only on each blade but also on the surface of other parts such as a tilting plate for covering and a center axis for rotating the blade. it can. The ventilation fan of the present invention can be used in various places. In particular, rooms with high airtightness that are easy to fill with organic gas such as formaldehyde emitted from building materials, kitchens to which oil vapor easily adheres, living rooms to which smoke from cigarettes easily adhere, sick rooms, bathrooms, toilets, etc. that require hygiene The effect is great when installed in

[0019]

【Example】

(Example) An aluminum blade having a thickness of 1 mm and a tilting plate made of aluminum having a thickness of 1 mm were prepared. On the surface of the wing, titania sol (ST: manufactured by Ishihara Sangyo Co., Ltd.) having water and alcohol as solvents, anatase type TiO ₂ : binder = 80: 20 (weight ratio), and solid content of 10% by weight.
-K01 (product number) "to form a surface layer of anatase-type TiO ₂ by applying a film having a thickness of 1 μm (when dried), heating and drying at 150 ° C. for 30 minutes to cure the coating. did. These three blades were used for a ventilation fan having the structure shown in FIG.

Comparative Example In Example 1, an unsaturated polyester resin paint using an organic sulfonic acid-based curing catalyst was used instead of forming a surface layer of anatase TiO ₂ to a thickness of 5 μm (when dried). Spray paint like
Heat curing was performed at 20 ° C. for 120 seconds to form a surface layer. And these three blades were used for the ventilation fan of the structure of FIG.

(Evaluation-formaldehyde removal performance) A closed room having an internal volume of 10 m ³ was made of a gypsum board with paper adhered to the front and back surfaces.
Using urea resin adhesive, a wallpaper was applied to an area of 10 m ² of the wall surface in the closed room. Then, the ventilating fan obtained in the example was attached to the wall hole of the room, and the formalin concentration was measured three days after the operation was stopped. During that time, light having a light intensity of 0.1 mW / cm ² was irradiated from a mercury lamp toward a ventilation fan. The same test was performed for the ventilation fan of the comparative example. The measurement results are as shown in Table 1.

[0022]

[Table 1]

As can be seen from Table 1, the ventilation fan of the comparative example did not show the effect of reducing formaldehyde floating in the room, but the ventilation fan of the example exhibited an anatase-type TiO ₂ particle contained therein. This has the effect of reducing formaldehyde floating in the room.

(Evaluation-Stain Resistance) Each of the blades of the example and the comparative example was cut out by 25 cm ^{2 to} obtain a test piece.
On the other hand, a test tank made of quartz glass was prepared which was filled with smoke obtained by extracting 1/3 of cigarette smoke through a filter for cigarettes into the air per liter of volume. Each test piece was placed in this test tank, and the intensity of the light beam was set to 0.
The test piece was irradiated for 150 hours at 1 mW / cm ² . Then, the amount of tan attached to the test piece was evaluated by the magnitude of the color difference ΔE before and after the test on the surface (the larger the ΔE, the larger the amount of adhesion). The color difference is measured using a spectrophotometer and the CI
Calculated by the color difference formula L ^* a ^* b ^{* of} E (International Commission on Illumination).

[0025]

[Table 2]

As can be seen from Table 2, the blade of the example had a smaller amount of tobacco tar attached than the blade of the comparative example, and had an effect of decomposing and removing the adhered tobacco tar.

(Evaluation-Antibacterial Property) Each of the blades of the examples and the comparative examples was cut into 25 cm ² pieces to prepare test pieces, and the inhibitory effect on bacteria was tested by the following method. Test strains • Escherichia coli IFO 3301
(Escherichia coli) Preparation of test bacterial solution In a normal broth medium (manufactured by Eiken Chemical Co., Ltd.) at 35 ° C., 16
The culture solution of the test bacteria cultured with shaking for 培養 20 hours was diluted 20,000-fold with a sterilized phosphate buffer to obtain a bacterial solution. The number of viable bacteria was separately measured for the bacterial solution. Antibacterial test 1 ml of bacterial solution was applied to the surface layer of the specimen (each wing of Example and Comparative Example).
At the start of the test and at 25 ° C. in an atmosphere of 25 ° C., irradiating the surface layer so that the intensity of light from the mercury lamp becomes 0.1 mW / cm ^2, and after storing for 3 hours, the number of bacteria is measured, and the antibacterial performance of the specimen Was determined. In addition, 1 ml of a bacterial solution was dropped on a petri dish as a control sample, and the same test was performed. Measurement of viable cell count The specimen and the control sample stored for 3 hours were washed away with 10 ml of SCDLP medium (manufactured by Nippon Pharmaceutical Co., Ltd.), and the rinse was washed on a pour plate using a standard agar medium (manufactured by Eiken Chemical Co., Ltd.). The number of viable bacteria was measured by a culture method (cultured at 35 ° C. for 2 days), and the number of bacteria per specimen and control sample was calculated. The detection limit in this case was 10.

[0028]

[Table 3]

As can be seen from Table 3, the blade of the comparative example has virtually no antibacterial effect, whereas the blade of the example has the effect of killing the attached bacteria.

[0030]

As described above, according to the present invention, exhaust fan of the present invention, the surface of the substrate constituting at least each of the blades, by providing the surface layer containing the anatase type TiO _2, the oil stains adhering to the surface, As it has the effect of decomposing organic dirt such as cigarette tar, the amount of dirt attached is reduced, the remaining dirt can be easily removed by wiping or washing with water, and the fungus attached to the surface is sterilized. Can keep a clean surface. Further, the indoor concentration of organic gas such as formaldehyde generated from floors and walls can be reduced.

[Brief description of the drawings]

FIG. 1 is a front view showing an example of a ventilation fan.

FIG. 2 is a front view showing a ventilation fan with blinds.

FIG. 3 is a sectional view of a blade.

FIG. 4 is a sectional view of another type of blade.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ventilation fan 2 Blade 3 Central axis 4 Frame 5 Tilt plate 6 Support axis 10 Base material 11 Surface layer 12 Barrier layer

Claims (1)

[Claims] 1. A ventilation fan having a plurality of blades, wherein a surface layer containing anatase-type TiO ₂ is provided on at least a surface of a base material constituting each blade.