JP6953107B2 - Enclosure - Google Patents

Description

The present invention relates to an enclosure, and more particularly to an enclosure to which a photocatalyst film is attached.

Patent Document 1 is effective in removing harmful components and foul odors contained in exhaust gas emitted by large vehicles such as heavy-duty trucks and dump trucks, and further, various types for decoration applied to the surface of the plate body. It makes it difficult for visible display elements such as patterns, colors, pictures, and characters for advertising to come off, and reapplies the visible display elements even if they are exposed to wind and rain for a long period of time after repeated use. A temporary enclosure that does not have to be re-doed and does not have the problem of generating volatile organic compounds (VOCs) is disclosed.

In this temporary enclosure plate, a coating film having photocatalytic activity is formed on at least one of the front and back surfaces of the plate body. Further, a visible display element is applied to the surface of the plate body, and a coating film having photocatalytic activity is formed on at least this coated surface. Further, a film having a coating film having photocatalytic activity is attached to at least one of the front and back surfaces of the plate body so that it can be freely attached.
Japanese Unexamined Patent Publication No. 2008-291617

However, the invention disclosed in Patent Document 1 has not been sufficiently verified for a coating film having photocatalytic activity, and in particular, from the viewpoint of preventing peeling of the coating film, from the viewpoint of the ability to decompose organic substances such as NOx or SOx, The viewpoint of developing hydrophilicity of the photocatalyst and the viewpoint of preventing deterioration of the coating film of the photocatalyst have not been considered.

Therefore, it is an object of the present invention to provide an enclosure plate to which a photocatalytic film having excellent photocatalytic activity and the like is attached.

In order to solve the above problems, the enclosure plate of the present invention is used.
It contains a nano-order size photocatalyst particle, a negatively charged substance having a zeta potential of −30 mV to −70 mV, which repels each other in a solvent containing the photocatalyst particle, and a resin in an uncured state. A photocatalyst film obtained by curing the photocatalyst coating liquid is attached.

The photocatalytic coating liquid, which is a photocatalytic film to be attached to the enclosure plate of the present invention, has photocatalytic activity due to light in a living environment and is self-cleaning property obtained by coating without going through a complicated process. It is an organic-inorganic hybrid photocatalyst coating liquid provided with. That is, the photocatalyst coating liquid according to the present invention typically obtains adhesion when a photocatalyst film is formed by hybridizing silica particles, a resin, and a photocatalyst.

For example, the photocatalyst particles are 3 wt% to 70 wt% with respect to the photocatalyst film produced using the photocatalyst coating liquid, and the negatively charged substance is 19 wt% to 80 wt% with respect to the photocatalyst film produced using the photocatalyst coating liquid. The resin may be selected from 3 wt% to 60 wt% with respect to the photocatalyst film produced by using the photocatalyst coating liquid. In the present specification, the description using the notation "wt%" for the photocatalyst coating liquid is a value converted into the amount when the photocatalyst coating liquid is dried to obtain a photocatalyst film. Therefore, it should be noted that, for example, even when the photocatalyst coating liquid is produced using a photocatalyst-containing material having a large amount of water, the amount of the photocatalyst-containing material in the photocatalyst coating liquid is larger than that described above.

The negatively charged substance may have a pH of 7 or more and less than 9, an average primary particle size of 1 nm or more, and an average secondary particle size of 4000 nm or less, and may contain silica.

The resin may contain any one of an acrylic resin, a silicone resin, a silicone resin, a urethane resin, and a fluororesin.

The photocatalyst particles may be photocatalyst particles in which flat crystal particles and three-dimensional crystal particles having a thickness relative to the flat crystal particles are bonded to each other.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First, an outline of a photocatalyst coating liquid serving as a photocatalyst film to be attached to the enclosure plate of the present embodiment will be described. Here, first, the composition of the photocatalyst coating liquid according to the present embodiment will be described, and then the production method and coating method thereof, and further the production method of the photocatalyst film will be described.

The photocatalyst coating liquid according to the present embodiment typically _{contains a photocatalyst-containing substance such as TiO 2} described below, a resin such as an acrylic resin, and a negatively charged substance such as silica particles.

[Photocatalyst-containing material]
The "photocatalyst-containing substance" that composes the photocatalyst coating liquid according to the present embodiment means a compound that has a photocatalytic action by itself, and can be converted into a photocatalyst by undergoing a required process. A compound containing a photocatalytic precursor.

The photocatalyst-containing material according to the present embodiment contains, for example, a so-called visible light responsive TiO ₂ photocatalyst containing photocatalyst particles in which flat crystal particles and three-dimensional crystal particles thicker than the flat crystal particles are bonded. It is a body. Specifically, but not limited to these, Sagan Coat TOsol85, TPX, TPX-HP, TPX-HL, TPX-VB, TPX-AD, TPX-ID, TPX-FxFC manufactured by Saba Corporation. , TPX-FxSP, TPX-FxFA, TPX-FxFN, etc. (all are product names). In addition, for any of these, for example, isopropyl alcohol (IPA) is mixed as a solvent in order to bring the photocatalytic paint, which is a water-based paint, into close contact with the surface of the base material. The mixing ratio thereof may be, for example, 100: 1 to 100: 100, preferably 100: 55 to 100: 75, although it depends on the type of photocatalyst coating liquid.

However, the material of the photocatalyst-containing material according to the present embodiment is _{not only TiO 2,} but also ZnO, SrTIO ₃ , CdS, CdO, InP, In ₂ O ₃ , BaTIO ₃ , K ₂ NbO ₃ , Fe ₂ O ₃ , and Ta. ₂ O ₅ , WO ₃ , Bi ₂ O ₃ , NiO, Cu ₂ O, SiO ₂ , MoS ₂ , MoS ₃ , InPb, RuO ₂ , CeO ₂ , GaP, ZrO ₂ , SnO ₂ , V ₂ O ₅ , KTaO ₃ , Nb ₂ O ₅ , CuO, MoO ₃ , Cr ₂ O ₃ , GaAs, Si, CdSe, CdFeO ₃ , RaRhO _{3, and the} like can be used.

Here, the visible light responsive photocatalyst-containing material refers to a photocatalyst-containing material capable of exhibiting photocatalytic action such as photocatalytic activity and hydrophilicity when irradiated with light having a wavelength of, for example, about 400 nm to about 800 nm. .. The photocatalyst coating liquid using this type of photocatalyst-containing body has an advantage that an environmental purification effect and an antifouling effect can be obtained mainly even in a place such as a room where the ultraviolet rays contained in sunlight are not sufficiently irradiated.

Further, the photocatalyst-containing material according to the present embodiment is unique in that it contains photocatalyst particles in which two different types of crystal particles are bonded, but a photocatalyst coating liquid containing photocatalyst particles composed of one type of crystal particles. However, it should be noted that this is not excluded from the scope of the present invention.

As confirmed by TEM photographs, of the above two types of crystal particles, the average size of the flat crystal particles falls within the range of about 3 nm to 40 nm in the plate surface direction, and the average is 10 nm. It is about 20 nm. The thickness of the flat photocatalyst particles is in the range of about 0.3 nm to 5.0 nm, and is about 1.0 nm to 3.0 nm on average. One of the characteristics of the photocatalyst-containing material according to the present embodiment is that it has a nano-order size.

The flat shape is defined as a general term for a shape that is relatively wide in the surface direction and relatively thin in the thickness direction. The surface includes not only a smooth surface but also a slightly uneven or curved surface. The shape of the surface is not limited, and any polygon such as a circle, an ellipse, a hexagon, or a quadrangle may be used.

The flat crystal particles are produced, for example, as follows. First, for example, about 10 mL of about 2.0 wt% to 2.5 wt% ammonia water is added dropwise to a dispersion liquid obtained by diluting about 10 mL of an aqueous solution of about 50 wt% to 70 wt% of titanium tetrachloride to about 1000 mL with distilled water. To produce a titanium hydroxide precipitate.

Then, the precipitate is extracted from the dispersion liquid by centrifugation, filtration, or the like, and then the titanium hydroxide gel itself is washed with pure water, ion-exchanged water, distilled water, or the like in order to remove impurities. Pure water, ion-exchanged water, or distilled water is added to the titanium hydroxide gel to produce a titanium hydroxide suspension having a volume of 100 mL to 500 mL.

Next, 10 mL to 20 mL of 30 wt% hydrogen peroxide solution is added to the titanium hydroxide suspension, and the mixture is stirred and then heated at a temperature of 65 ° C. to 400 ° C. for, for example, 2 hours to 15 hours. As a result, a photocatalyst stock solution containing titanium oxide, which is an anatase crystal in the shape of an arrowhead, can be obtained. In addition, titanium oxide having an incomplete crystallization of 5 nm or less remains in this photocatalyst stock solution.

A peroxo group will be modified on the surface of the titanium oxide. Therefore, in the photocatalyst stock solution, the polarization of the peroxo group exerts an electrical repulsive force between the particles, and the titanium oxides repel each other and do not aggregate. Ammonium ions and the like in the photocatalyst stock solution also contribute to the above dispersion. Therefore, the photocatalyst stock solution becomes a liquid in which titanium oxide is uniformly dispersed. Further, the titanium oxide thus produced will have one or more OH groups.

Next, the three-dimensional crystal particles contained in the photocatalyst-containing material according to the present embodiment will be described. The three-dimensional crystal particles mean, for example, those having various three-dimensional shapes such as a substantially spherical shape, a substantially elliptical cross section, a circular shape, a square shape, and these polygonal linear shapes. The three-dimensional crystal particles are defined as a general term for shapes in which the relative difference between the plane direction and the thickness direction is small, unlike the flat crystal particles described above.

Further, in the present embodiment, the average size of the flat crystal particles is set to be equal to or larger than the average size of the three-dimensional crystal particles. In this way, the three-dimensional crystal particles enter into the gaps between the flat crystal particles, and the titanium both oxides are mixed with each other as described later.

The three-dimensional crystal particles are produced, for example, as follows. First, a sulfate is produced by reacting ilmenite ore, which is mainly composed of iron oxide and titanium oxide, with sulfuric acid. Next, impurities are removed from the sulfate, and then the sulfate is hydrolyzed to precipitate an insoluble white titanium hydroxide. At this time, one or more OH groups are formed.

Then, this is neutralized and washed, dried or fired, and finely divided until it becomes a substantially spherical shape having an average size of about 6 nm and little variation in size. The titanium oxide thus produced will have one or more OH groups.

The above production method is a so-called sulfuric acid method, but is not limited to this, and other production methods such as a chlorine method, a hydrofluoric acid method, a titanium tetrachloride potassium method, a titanium tetrachloride aqueous solution method, and an alkoxide hydrolysis method are used. The method may be used.

Further, in the photocatalyst-containing material according to the present embodiment, various dopants are introduced into titanium oxide and the high temperature of titanium oxide is introduced so that the photocatalytic action can be obtained by irradiation with visible light so as to have a band gap capable of absorbing the visible light region. Reduction, high-energy irradiation such as X-ray to titanium oxide may be performed.

_{Next, a method for producing a so-called visible light responsive TiO 2} photocatalyst-containing material containing photocatalyst particles in which flat crystal particles and three-dimensional crystal particles are bonded will be described.

First, the three-dimensional crystal particles are mixed with the photocatalyst stock solution containing the flat crystal particles, and if necessary, the photocatalyst stock solution is stirred to bond the two. Here, as described above, the flat crystal particles are modified with a peroxo group and dispersed in the photocatalyst stock solution. Therefore, it is preferable to add the three-dimensional crystal particles while maintaining this state.

At the time of this addition, the concentration of peroxotitanic acid is, for example, 5 wt% or less in order to avoid a decrease in peroxo groups or a decrease in impurities such as an ammonium ion concentration that contributes to the above dispersion in the photocatalyst stock solution. However, it is preferable that impurities such as ammonium ions do not become 100 ppm or less, for example.

In this way, when the three-dimensional crystal particles are mixed with the photocatalyst stock solution containing the flat-shaped crystal particles, both the flat-shaped crystal particles and the three-dimensional crystal particles have one or more OH groups. Therefore, both crystal particles are hydrogen-bonded at each other's OH group portions.

[resin]
Next, the resin constituting the photocatalyst coating liquid according to the present embodiment will be described. It is said that the use of the photocatalyst film is not limited if the resin according to the present embodiment has a translucent finish when the photocatalyst film is manufactured, preferably a highly transparent finish. There is an advantage in that.

The resin according to the present embodiment may be an aqueous resin or a solvent-based resin, but it is preferable to use an aqueous resin from the viewpoint of environmental consideration. Examples of water-based resins include acrylic resin, acrylic urethane (acrylic polyol), acrylic silicon resin, aqueous silicone, block polymer of silicone resin and acrylic resin, acrylic styrene resin, sorbitan fatty acid ethylene oxide, and sorbitan fatty acid. There are crosslinked urethanes of esters, urethane-based acetates, polycarbonate diols and / or polyisocyanates, urethane dispersions, crosslinked polyacrylic acid ester and the like.

[Negatively charged substance]
In the present embodiment, as the negatively charged substance, for example, colloidal silica in which silica particles are colloidally dispersed in water or an organic solvent, sodium silicate (for example, high molar sodium silicate), silica compound (for example, ammonium silicate) and the like. , Silica-containing ones can be used. As the negatively charged substance, it is preferable to use a substance that also functions as a binder with the coated surface of the photocatalyst coating liquid. This has the advantage that when the photocatalyst film produced using the photocatalyst coating liquid is attached to the application target, it is not necessary to form an adhesive layer or the like between the photocatalyst film and the coated surface of the photocatalyst coating liquid. As the negatively charged substance according to this embodiment, a substance having a zeta potential (interfacial electrokinetic potential) of about -30 mV to -70 mV is used.

As a result of the negatively charged substance according to the present embodiment repelling the photocatalyst particles in the photocatalyst-containing body that are negatively charged in the liquid containing the photocatalyst-containing substance, there are positively charged substances and negatively charged substances in the resin. and which, but for the photocatalyst particles Ti-O ^- If you are a stabilizing while repel is, Si-O for negatively charged substances ^{- -} and Ti-O is stabilized while the can repel ^- and Si-O .. That is, the resin has a light hydrogen bond with a negatively charged substance having a relatively small molecular weight, and these bonds repel each other because the negatively charged substance has negative ions when the photocatalyst particles come close to each other. It stabilizes and slows the photocatalyst particles from decomposing the resin.

As a result, specifically, on the photocatalyst film, the resin layer having a relatively easy-adhesion treatment on the surface layer of the base material has an electric double layer, and the valence electrons form a Stern layer near the interface. Form. As a result, many negatively charged substances and photocatalyst particles are present on the surface of the photocatalyst film in a state of repulsion.

When the photocatalyst film on which the photocatalyst is located on the surface is irradiated with visible light or the like, photocatalytic activity that fully utilizes the ability of the photocatalyst can be obtained. In other words, if an attempt is made to manufacture a photocatalyst film without using a negatively charged substance, many photocatalyst particles will be located in the resin, and even if the photocatalyst film is irradiated with visible light or the like, electrons will jump out in the vicinity thereof. This makes it impossible to obtain sufficient photocatalytic activity.

Further, the lower limit of pH of the negatively charged substance according to the present embodiment is preferably about 7. This is because if it is less than this, the photocatalyst coating liquid will gel. On the other hand, the upper limit of the pH of the negatively charged substance is preferably 9 or less. If it exceeds this, the photocatalyst coating liquid becomes cloudy, and a photocatalyst film having translucency cannot be obtained. In other words, when the photocatalytic film according to the present embodiment does not have to have translucency, the pH of the negatively charged substance may exceed 9.

In the negatively charged substance according to the present embodiment, the lower limit of the particle size in the average primary particle size is preferably 1 nm, preferably 5 nm. This is because the storage stability of the photocatalyst coating liquid tends to decrease as the particle size becomes smaller, and if it is less than 1 nm, it is difficult to secure the storage stability of the photocatalyst coating liquid according to the present embodiment. In other words, when the photocatalyst coating liquid is used after being manufactured without being stored for a very long period of time, a negatively charged substance having a particle size smaller than the above may be adopted. The measurement of the primary particle size of the negatively charged substance is carried out by G.I. W. Sears, Jr. The Sears method described in "Analytical Chemistry 28, 1981-1983 (1956)" is used.

The upper limit of the particle size of the negatively charged substance is preferably 400 nm, preferably 100 nm, and more preferably 50 nm. This is because the larger the particle size, the lower the transparency of the photocatalyst film. In other words, when the photocatalytic film according to the present embodiment does not have to have translucency, the particle size of the negatively charged substance may exceed 400 nm, specifically, the average secondary particle size. The upper limit can be about 4000 nm.

A negatively charged substance that satisfies each of the above requirements can be used in the state of an aqueous dispersion, whether it is acidic or basic. The nature of the negatively charged substance to be used may be appropriately selected depending on the photocatalyst-containing material to be mixed and the stable region of the resin.

[Manufacturing method of photocatalyst coating liquid]
As described above, the produced photocatalyst-containing material, the resin, and the negatively charged substance are mixed. Specifically, first, the photocatalyst-containing substance is stirred at a rotation speed of, for example, about 100 rpm to 700 rpm, and a negatively charged substance is charged therein.

The stirring time depends on the charging rate of the negatively charged substance to the photocatalyst-containing substance, the total amount of the photocatalyst-containing substance and the negatively charged substance, the size of the stirring blade, etc. If the total amount of the negatively charged substance is about 40 kL, it may be about 30 minutes.

Subsequently, the resin is added thereto while stirring the photocatalyst-containing material containing the negatively charged substance after stirring at a rotation speed of, for example, about 100 rpm to 700 rpm.

The stirring time depends on the rate at which the resin is added to the photocatalyst-containing material containing a negatively charged substance, but at room temperature, for example, about 40 kL of the photocatalyst-containing material containing a negatively charged substance is about 20 kL. When the resin of the above is added, it may take about 20 minutes.

Metals such as Ag, Cu, and Zn can be further added to the photocatalyst coating liquid according to the present embodiment. The surface layer to which such a metal is added can kill bacteria, molds and algae adhering to the surface even in a dark place, and thus can further improve antibacterial properties. The addition amount may be about 1 wt% to 5 wt%.

Platinum group metals such as Pt, Pd, Ru, Rh, Ir, and Os can be further added to the photocatalyst coating liquid according to the present embodiment. The surface layer to which such a metal is added can enhance the redox activity of the photocatalyst, and can improve the decomposability of organic stains and the decomposability of harmful gases and malodors. The addition amount may be about 1 wt% to 5 wt%.

[Photocatalyst coating liquid coating method]
The photocatalyst coating liquid according to the present embodiment can form a photocatalyst coating film having high hydrophilicity by applying and curing the surface of various base materials. The base material is not particularly limited as long as it can form a photocatalytic coating film. Examples of the material of the base material include various materials such as wood, an organic material including paper, an inorganic material containing metal, and a mixture or compound thereof.

For example, as organic materials, vinyl chloride resin, polyethylene, polypropylene, polycarbonate, acrylic resin, polyacetal, fluororesin, silicone resin, ethylene-vinyl acetate copolymer (EVA), acrylonitrile-butadiene rubber (NBR), polyethylene terephthalate ( Synthetic resin materials such as PET), ethylene-vinyl alcohol copolymer (EVOH), polyimide resin, polyphenylene sulfide (PPS), acrylonitrile-butadiene-styrene (ABS) resin, melamine resin, natural, synthetic or semi-synthetic fiber materials. And textile products, but it is particularly preferable to use a polyvinyl chloride resin having a good balance in weather resistance, strength, and price. Further, due to the nature of the temporary enclosure, it is preferable to use a base material that is opaque and has concealing performance. These may be commercialized in a required shape and configuration such as a photocatalyst film, other molded products, and a laminate.

When the base material is made of an organic material, it is preferable to surface-activate the base material in advance. By this treatment, the wettability and coatability of the photocatalyst coating liquid according to the present embodiment to the substrate are improved. As the surface activation treatment, for example, corona treatment, normal pressure (or atmospheric pressure) plasma treatment, low pressure low temperature plasma treatment, easy adhesion treatment and the like can be used.

Examples of the inorganic material include glass and ceramic materials. These can be commercialized in various forms such as tiles, insulators and mirrors. Moreover, metal is mentioned as an inorganic material. This includes cast iron, steel, iron, iron alloys, aluminum, aluminum alloys, nickel, nickel alloys, zinc diecasts and the like, which may be plated and organically coated. Further, it may be a metal plating coating applied to the surface of an inorganic or organic material.

[Manufacturing method of photocatalytic film]
Next, a method for producing the photocatalyst film according to the present embodiment will be described. The photocatalyst film according to the present embodiment was first selected and selected under the condition that the thickness of the resin film as a base material is, for example, 10 μm to 300 μm, preferably 50 μm to 250 μm, and more preferably 50 μm to 150 μm. A photocatalyst coating solution is applied to the surface layer of the base material under the condition that the thickness is, for example, 0.1 μm to 100 μm, preferably 0.1 μm to 50 μm, and more preferably 0.1 μm to 5.0 μm. Apply to.

This coating method may be a known one, and specifically, a dip coating method, a spin coating method, a spray coating method, a brush coating method, an impregnation method, a roll method, a wire bar method, a die coating method, or a direct gravure coating method. , Microgravure coating method, inkjet method, reverse coating method and the like may be used. Further, the coating speed may be 1 mpm to 100 mmp, preferably 10 mpm to 70 mmp. Further, coating ^{amount, 10g / m 2 wet~300g / m} 2 wet, may be preferably a condition to be ^{10g / m 2 wet~50g / m 2} wet.

Subsequently, the film manufacturing apparatus base coated with the photocatalyst coating liquid is conveyed into a drying furnace and dried by heating with hot air drying, a far-infrared heater, a panel heater, or the like to cure the photocatalyst coating liquid. At this time, the drying temperature may be 30 ° C. to 160 ° C., preferably 40 ° C. to 100 ° C.

The reason for applying the photocatalyst coating liquid under the condition that the thickness of the photocatalyst film is within the above range is that if the coating thickness is less than the above lower limit, the photocatalytic activity as the photocatalyst film cannot be sufficiently obtained. On the other hand, if the above upper limit is exceeded, the photocatalyst film or its precursor during production may be peeled off from the film production equipment base, cracked, or warped, resulting in a decrease in the durability of the thin film. This is because it will be done.

[How to attach the photocatalyst film to the enclosure]
In the present embodiment, in order to make it easy to attach the photocatalyst film to the surrounding plate, a photocatalyst coating liquid to be a photocatalyst film is provided on one surface of the polyvinyl chloride film or the like, and the polyvinyl chloride film or the like is provided. An adhesive layer is provided on the other surface of the adhesive layer, and the surface of the adhesive layer is covered with a release paper or a release film of silicone or other release agent.

In this way, when the photocatalyst film is attached to the enclosure plate at any place, the release paper or the like can be removed and the adhesive layer can be attached to the enclosure plate. However, it is not essential that the photocatalyst film according to the present embodiment is provided with a release paper or the like, and therefore, it is possible to directly apply the photocatalyst film to a base material such as paper.

Here, in producing the adhesive layer, various resins such as solvent type, emulsion type, solvent-free acrylic type, rubber type, urethane type, and silicone type are used. One of these or a mixture of some of these is applied to a release paper or the like. At this time, a comma method, a gravure method, a Mayer bar method, a die coating method, a roll method, a reverse coating method, a dip method and the like can be used. The coating speed may be 1 mpm to 100 mmp, preferably 10 mpm to 70 mmp. Further, coating ^{amount, 10g / m 2 dry~300g / m} 2 dry, it may be preferably a condition to be ^{20g / m 2 dry~60g / m 2} dry.

Subsequently, the release paper or the like coated with the above-mentioned various resins or the like is conveyed into a drying furnace and cured by hot air drying, heating and drying with a far-infrared heater, a panel heater, or the like. At this time, the drying temperature may be 30 ° C. to 150 ° C., preferably 60 ° C. to 110 ° C.

The photocatalyst film according to this embodiment will be described in each of the examples below.
(1) Since it has excellent adhesion, it has the advantage that it is difficult to peel off even from polyvinyl chloride film, which is generally difficult to secure adhesion, and even if an external force is applied during transportation of the enclosure plate, etc. Hard to peel off
(2) In addition, since it has an excellent ability to decompose organic matter, effective air purification is possible, and because it is also a visible light responsive type, it is not only an enclosure used at outdoor construction sites, but also indoor construction sites. It is also suitable as an enclosure for use in
(3) Since the photocatalyst exhibits hydrophilicity and has excellent self-cleaning properties, it is of course suitable for use at outdoor construction sites.
(4) Since the coating film of the photocatalyst is less likely to deteriorate, there are advantages in terms of adhesion and outdoor use.

For the enclosure plate of the present embodiment, for example, the photocatalyst film on the surface may be replaced regularly or irregularly. This is because even if the photocatalyst film is slightly peeled off by use, it can be returned to a new state. This is also an advantage that cannot be obtained in the case of a baking finish type enclosure.

From a different point of view, in the case of a baking-painting type enclosure, the enclosure is cleaned and dried regularly or irregularly, and if necessary, transported to the painting site for repainting. Various operations such as are required. On the other hand, the photocatalyst film re-covering work can be easily performed, the cost can be reduced, and the emission of carbon dioxide generated by using a transport vehicle during transportation can be reduced. ..

The application target of the photocatalyst film is not limited to the polyvinyl chloride film, but may be various resin films described in the examples, other resin films, and further include metals and the like. Needless to say.

Although the resin film will be described as an example of the enclosure plate of the present invention, it should be noted that the scope of the present invention is not limited to these examples.

(Example 1)
In this embodiment, first, a photocatalytic coating liquid (manufactured by TPX-FxFC Saba Corporation) and isopropyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd.) are blended in a ratio of, for example, 100: 55 to 75. Further, the surface of the base material is coated with the isopropyl alcohol as a base material to perform a surface activation treatment to improve the adhesion to the photocatalyst coating liquid or the like containing the isopropyl alcohol. Then, the PVC film base material (manufactured by Towa Synthetic Industry Co., Ltd.) was coated with a direct gravure coating method, for example, a coating amount of 10 g / m ² dry to 50 g / m ² wet, and a drying temperature of, for example, 40 ° C to 100 ° C. The coating treatment was performed under the condition that the coating speed was, for example, 10 mpm to 70 mpm.

(Example 2)
This example differs from Example 1 only in that it has not been surface-activated. That is, in this embodiment, a photocatalytic coating liquid (manufactured by TPX-FxFC Saba Corporation) and isopropyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd.) are blended at a ratio of, for example, 100: 55 to 75, and a vinyl chloride film base material (manufactured by Wako Pure Chemical Industries, Ltd.) is blended. Towa respect Gosei Co., Ltd.) at a direct gravure coating method, the coating amount for example ^{10g / m 2 wet~50g / m 2} wet, drying temperature, for example 40 ° C. to 100 ° C., the coating speed for example 10mpm~ The coating treatment was performed under the condition of 70 mpm.

(Example 3)
Compared with Example 1, this example is different in the type of photocatalyst coating liquid in addition to the fact that the surface activation treatment is not applied. That is, in this embodiment, a photocatalytic coating liquid (manufactured by TPX-FxFA Saba Corporation) and isopropyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd.) are blended at a ratio of, for example, 100: 55 to 75, and a vinyl chloride film base material (manufactured by Wako Pure Chemical Industries, Ltd.) is blended. Towa respect Gosei Co., Ltd.) at a direct gravure coating method, the coating amount for example ^{10g / m 2 wet~50g / m 2} wet, drying temperature, for example 40 ° C. to 100 ° C., the coating speed for example 10mpm~ The coating treatment was performed under the condition of 70 mpm.

(Example 4)
This example differs from Example 1 in various points. That is, in this embodiment, the photocatalyst coating liquid (manufactured by TPX-FxFA Saba Corporation) and isopropyl alcohol are blended at a ratio of about 100:65, and the PVC film base material (manufactured by Towa Synthetic Industry Co., Ltd.) is mixed. hand-painted, for example, 20 g / m ^2, the drying temperature, for example 100 ° C., the coating treatment was carried out under conditions that the drying time for example, 5 minutes.

(Comparative Example 1)
As this comparative example, a vinyl chloride film base material (manufactured by Towa Synthetic Industry Co., Ltd.) that has not been coated with the photocatalyst coating liquid as described above was prepared.

(Comparative Example 2)
This example is relatively close to the conditions in Example 4, but the type of photocatalyst coating liquid, the fact that isopropyl alcohol is not mixed with the photocatalyst coating liquid, and the surface activation treatment are applied. It is different from the point that it is not. That is, in this comparative example, the photocatalytic coating liquid (manufactured by TPX-FxFC Saba Corporation) was manually applied to a vinyl chloride film base material (manufactured by Towa Synthetic Industry Co., Ltd.) at 20 g / m ² and the drying temperature was 100 ° C. The coating treatment was carried out under the condition that the drying time was 5 minutes.

Next, using the photocatalyst coating liquids of each Example and each Comparative Example, a photocatalyst film having a thickness of 1 μm was formed by the method described in the embodiment. Each of these photocatalytic films was measured or evaluated for the following items.

1. 1. Evaluation of appearance 2. Degradation activity: Evaluation of degradation activity according to JIS R1703

Regarding the decomposition activity, since the titanium oxide used in this coating liquid was recognized to have visible light responsiveness, visible light was irradiated instead of ultraviolet light.

Table 1 summarizes various preconditions and measurement results of each of the above-described Examples and Comparative Examples.

First, let us consider a comparative example.
In Comparative Example 1, since the photocatalyst coating liquid was not applied to the PVC film base material in the first place, the decomposition activity was −0.07. That is, it can be seen that in Comparative Example 1, photocatalytic activity such as decomposition activity cannot be obtained.

Further, in Comparative Example 2, although the photocatalyst coating liquid was applied to the vinyl chloride film base material, isopropyl alcohol was not blended in the photocatalyst coating liquid. Therefore, the photocatalyst coating liquid did not sufficiently wet and spread on the PVC film base material, and as a result, the desired photocatalyst coating film was not formed on the PVC film base material in appearance. Therefore, it can be seen that even in Comparative Example 2, the desired photocatalytic action cannot be obtained as a result.

On the other hand, in each of Examples 1 to 4, no abnormal appearance was observed, and an excellent decomposition activity effect was confirmed. In addition, if the decomposition activity has a value of 5.0 or more, it can be said that there is a predetermined self-cleaning performance set by the Photocatalyst Industry Association. Therefore, all of the examples have the self-cleaning performance. You will be doing.

In addition, it can be seen that in Example 1, since the surface activation treatment is performed, higher decomposition activity can be obtained as compared with Example 2 in which the surface activation treatment is not performed. However, in Example 3, although the surface activation treatment was not performed, it can be seen that higher decomposition activity can be obtained than that in Example 2 by changing the type of the photocatalyst coating liquid. Further, in Example 4, although the surface activation treatment is not performed, high decomposition activity can be obtained by using a photocatalyst coating liquid in which isopropyl alcohol is blended in an appropriate ratio according to the type of the photocatalyst coating liquid. You can see that.

In this example, isopropyl alcohol has been mentioned as an example of the solvent to be blended in the photocatalyst coating liquid, but the present invention is not limited to this, and ethanol, water and the like can also be used.

Claims (8)

A negatively charged substance having a zeta potential of -30 mV to -70 mV in a stock solution that repels each other between the nano-order size photocatalyst particles and the photocatalyst particles in a solvent containing the photocatalyst particles, and an uncured resin. , A step of mixing isopropyl alcohol as a solvent with the water-based coating material containing the photocatalyst particles at a ratio of 100: 1 to 100: 100 to produce a photocatalyst coating liquid.
After applying the photocatalyst coating liquid to a resin film having a thickness in the range of 10 μm to 300 μm so as to have a thickness in the range of 0.1 μm to 100 μm at a coating rate of 1 mpm to 100 mmp, the photocatalyst coating liquid is cured, and then cured. The step of producing a photocatalyst film in which more negatively charged substances and photocatalyst particles are present in the surface part of the photocatalyst coating liquid than in other parts other than the surface.
Steps to attach the photocatalyst film to the enclosure and
A method of manufacturing an enclosure including. The photocatalyst particles are 3 wt% to 70 wt% with respect to the photocatalyst film produced by using the photocatalyst coating liquid.
The negatively charged substance is 19 wt% to 80 wt% with respect to the photocatalyst film produced by using the photocatalyst coating liquid.
The method for producing an enclosure according to claim 1, wherein the resin is selected from 3 wt% to 60 wt% with respect to the photocatalyst film produced by using the photocatalyst coating liquid. The method for producing an enclosure according to claim 1, wherein the negatively charged substance has a pH of 7 or more and 9 or less. The method for producing an enclosure according to claim 1, wherein the negatively charged substance has an average primary particle size of 1 nm or more and an average secondary particle size of 4000 nm or less. The method for producing an enclosure according to claim 1, wherein the negatively charged substance contains silica. The method for manufacturing an enclosure according to claim 1, wherein the resin contains any one of an acrylic resin, a silicone resin, a silicone resin, and a urethane resin. The method for producing an enclosure according to claim 1, wherein the photocatalyst particles are photocatalyst particles in which flat crystal particles and three-dimensional crystal particles having a thickness relative to the flat crystal particles are bonded to each other. A method for producing a photocatalyst film for an enclosure, which is obtained by curing the photocatalyst coating liquid according to claim 1.