JP2017048509A - Shroud - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shroud on which a photocatalytic film with excellent photocatalytic activity and the like is stuck.SOLUTION: In a shroud, a photocatalytic film is positioned on a surface. The photocatalytic film is formed by curing a photocatalyst coating liquid including photocatalytic particles of a nano-order size, a negatively charged substance with a zeta potential from -30 mV to -70 mV, which mutually repels the photocatalytic particles in a solvent including the photocatalytic particles, and resin in an uncured state.SELECTED DRAWING: None

Description

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

  Patent Document 1 is effective in removing harmful components and bad odors contained in exhaust gas exhausted by large vehicles such as heavy-duty vehicles and dump trucks, and various kinds of decorations applied to the surface of the plate body. Makes visible display elements such as patterns, colors, pictures, letters for advertisements, etc. difficult to peel off. A temporary enclosure that does not have to be repeated and does not have the problem of generation of volatile organic compounds (VOC) is disclosed.

This temporary enclosure has a coating film having photocatalytic activity 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 the application surface. Moreover, the film which formed the coating film which has a photocatalytic activity on at least one surface of the front and back of a board main body shall be pasted as it can be replaced freely.
JP 2008-291617 A

  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, No consideration has been given to the viewpoint of the hydrophilicity of the photocatalyst and the viewpoint of preventing the deterioration of the coating film of the photocatalyst.

  Then, this invention makes it a subject to provide the enclosure board on which the photocatalyst film which has the outstanding photocatalytic activity etc. was stuck.

In order to solve the above problems, the shroud of the present invention is
A nano-order photocatalyst particle, a negatively charged substance having a zeta potential of −30 mV to −70 mV repelling each other in the solvent containing the photocatalyst particle, and an uncured resin A photocatalyst film obtained by curing the photocatalyst coating solution is attached.

  The photocatalyst coating liquid to be a photocatalyst film attached to the shroud of the present invention has photocatalytic activity by light in a living environment, and can be obtained by coating without a complicated process. Is an organic-inorganic hybrid photocatalyst coating solution. That is, the photocatalyst coating liquid according to the present invention typically has a silica particle, a resin, and a photocatalyst that are hybridized to obtain adhesion when a photocatalyst film is formed.

  For example, the photocatalyst particles are 3 wt% to 70 wt% with respect to the photocatalyst film manufactured using the photocatalyst coating liquid, and the negatively charged substance is 19 wt% to 80 wt% with respect to the photocatalyst film manufactured using the photocatalyst coating liquid. The resin may be selected from 3 wt% to 60 wt% with respect to the photocatalyst film produced using the photocatalyst coating solution. In addition, the description location using the notation “wt%” with respect to the photocatalyst coating liquid in the present specification is a value converted into an amount when the photocatalyst film is dried. Therefore, it should be noted that, for example, even when a photocatalyst coating liquid is produced using a photocatalyst-containing body having a high water content, the photocatalyst-containing body in the photocatalyst coating liquid is larger than the above.

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

  The resin may include any of acrylic resin, silicon resin, silicone resin, urethane resin, and fluororesin.

  The photocatalyst particles are preferably photocatalyst particles in which flat crystal particles and three-dimensional crystal particles having a thickness are combined with each other.

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

  First, the outline | summary of the photocatalyst coating liquid used as the photocatalyst film stuck on the enclosure board of this embodiment is demonstrated. Here, first, the composition of the photocatalyst coating liquid according to the present embodiment will be described, and then the manufacturing method and coating method thereof, and further the manufacturing method of the photocatalytic film will be described.

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

[Photocatalyst-containing body]
The “photocatalyst-containing body” that constitutes the photocatalyst coating liquid according to the present embodiment refers to a compound that itself has a photocatalytic action, and can also be converted into a photocatalyst through a required process. The thing containing a photocatalyst precursor is said.

The photocatalyst-containing body according to the present embodiment includes, for example, a so-called visible light responsive TiO ₂ photocatalyst containing photocatalyst particles in which flat crystal particles and solid crystal particles having a thickness compared to the flat crystal particles are combined. The body. Specifically, although not limited to these, Sagan Coat TOsol 85, TPX, TPX-HP, TPX-HL, TPX-VB, TPX-AD, TPX-ID, TPX-FxFC manufactured by Sakai Corporation , TPX-FxSP, TPX-FxFA, TPX-FxFN, etc. can be used (all are product names). In addition, for example, isopropyl alcohol (IPA) is mixed as a solvent with any of these in order to bring the photocatalyst paint that is a water-based paint into close contact with the substrate surface. The mixing ratio may be, for example, 100: 1 to 100: 100, and preferably 100: 55 to 100: 75, although it depends on the type of photocatalyst coating liquid.

However, the material of the photocatalyst-containing body according to the present embodiment, not only the _{TiO 2, ZnO, SrTiO 3,} CdS, CdO, InP, In 2 O 3, BaTiO 3, K 2 NbO 3, Fe 2 O 3, 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, or the like can be used.

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

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

  As confirmed by a TEM photograph, of the above two types of crystal particles, the flat crystal particles have an average size within the range of about 3 nm to 40 nm in the plate surface direction, and an average of 10 nm. About 20 nm. Further, the thickness of the flat photocatalyst particles falls within the range of about 0.3 nm to 5.0 nm, and is about 1.0 nm to 3.0 nm on average. The photocatalyst-containing body according to this embodiment is one of the characteristic points that it is nano-order size.

  The flat shape is defined as a generic name of 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 may be any shape such as a circle, an ellipse, a hexagon, or a polygon such as a quadrangle.

  Flat crystal particles are produced, for example, as follows. First, about 10 mL of about 2.0 wt% to 2.5 wt% aqueous ammonia is dropped into a dispersion 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. Thus, a precipitate of titanium hydroxide is produced.

  Then, the precipitate is extracted from the dispersion 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 for removing 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 to 20 mL of 30 wt% hydrogen peroxide solution is added to the titanium hydroxide suspension and stirred, and then heated at a temperature of 65 to 400 ° C. for 2 to 15 hours, for example. As a result, a stock solution of photocatalyst containing titanium oxide of an anatase crystal having a bowl shape can be obtained. In this photocatalyst stock solution, incompletely crystallized titanium oxide of 5 nm or less remains.

  A peroxo group is modified on the surface of the titanium oxide. For this reason, in the stock solution of photocatalyst, electric repulsion between particles works due to the polarization of the peroxo group, and titanium oxides repel each other so that they do not aggregate. Note that ammonium ions and the like in the photocatalyst stock solution also contribute to the dispersion. For this reason, the photocatalyst stock solution is a liquid in which titanium oxide is uniformly dispersed. In addition, the titanium oxide thus produced has one or more OH groups.

  Next, the three-dimensional crystal particles included in the photocatalyst-containing body according to the present embodiment will be described. The three-dimensional crystal particles mean various three-dimensional shapes such as a substantially spherical shape, a substantially elliptical cross section, a circular shape, a square shape, and a polygonal shape thereof. The three-dimensional crystal particle is defined as a generic name of a shape having a small relative difference between the plane direction and the thickness direction, unlike the above-described flat crystal particle.

  In the present embodiment, the average size of the flat crystal particles is equal to or greater than the average size of the three-dimensional crystal particles. If it carries out like this, a solid-shaped crystal particle will enter into the clearance gap between flat crystal particles, and also both titanium oxides will mutually be mixed so that it may mention later.

  The solid crystal particles are produced, for example, as follows. First, a sulfate is produced by reacting ilmenite ore whose main components are iron oxide and titanium oxide with sulfuric acid. Next, after removing impurities from the sulfate, the sulfate is hydrolyzed to precipitate insoluble white hydrous titanium oxide. At this time, one or more OH groups are formed.

  Thereafter, this is neutralized and washed, dried or baked, and fine particles are formed until the average size becomes about 6 nm and becomes a substantially spherical shape with little variation in size. The titanium oxide produced in this way 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 chlorine method, hydrofluoric acid method titanium potassium chloride method, titanium tetrachloride aqueous solution method, alkoxide hydrolysis method, etc. A method may be used.

  In addition, the photocatalyst-containing body according to the present embodiment introduces various dopants with respect to titanium oxide, the high temperature of titanium oxide so as to obtain a band gap capable of absorbing visible light so that a photocatalytic action can be obtained by irradiation with visible light. Reduction, irradiation with high energy such as X-rays with respect to titanium oxide may be performed.

Next, a method for producing a so-called visible light responsive TiO ₂ photocatalyst-containing body including photocatalyst particles in which flat crystal particles and three-dimensional crystal particles are combined will be described.

  First, three-dimensional crystal particles are mixed with a photocatalyst stock solution containing flat crystal particles, and if necessary, the photocatalyst stock solution is agitated to combine them. Here, as described above, since the flat crystal particles are modified with peroxo groups and dispersed in the photocatalyst stock solution, it is preferable to add the three-dimensional crystal particles while maintaining this state.

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

  Thus, when three-dimensional crystal particles are mixed with a photocatalyst stock solution containing flat crystal particles, both the flat crystal particles and the three-dimensional crystal particles have one or more OH groups. Therefore, both crystal grains are hydrogen-bonded at the OH group portion of each other.

[resin]
Next, the resin constituting the photocatalyst coating liquid according to this embodiment will be described. The resin according to the present embodiment is such that when the photocatalyst film is produced, the use of the photocatalyst film is not limited when the photocatalyst film is produced, and preferably, when the photocatalyst film has a highly transparent finish. There are advantages in terms.

  The resin according to this embodiment may be a water-based resin or a solvent-based resin, but it is preferable to use a water-based resin from the viewpoint of environmental considerations. Examples of water-based resins include acrylic resin, acrylic urethane (acrylic polyol), acrylic silicone resin, aqueous silicone, block polymer of silicone resin and acrylic resin, acrylic styrene resin, sorbitan fatty acid ethylene oxide, sorbitan fatty acid Examples include ester, urethane acetate, polycarbonate diol and / or polyisocyanate cross-linked urethane, urethane dispersion, and cross-linked polyacrylic acid acrylic ester.

[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), or the like. A material containing silica can be used. As the negatively charged substance, a substance that also functions as a binder with the coating surface of the photocatalyst coating liquid may be used. If it carries out like this, when sticking the photocatalyst film manufactured using the photocatalyst coating liquid to the sticking object, there exists an advantage that it becomes unnecessary to form an adhesive layer etc. between the coating surfaces of a photocatalyst coating liquid. As the negatively charged substance according to this embodiment, a substance having a zeta potential (electrokinetic potential) of about −30 mV to −70 mV is used.

The negatively charged substance according to this embodiment repels the photocatalyst particles in the photocatalyst-containing body that is negatively charged in the liquid containing the photocatalyst-containing body. As a result, the resin has a positively charged substance and a negatively charged substance. 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 . In other words, the resin has a light hydrogen bond with a negatively charged substance having a relatively low molecular weight, and these bonds repel each other because the negatively charged substance has negative ions when the photocatalyst particles are in the vicinity. Stabilizes and slows down the photocatalytic particles decomposing the resin.

  Thus, specifically, on the photocatalyst film, the resin layer having a relatively + ion obtained by subjecting the substrate surface layer to an easy adhesion treatment has an electric double layer, and the valence electrons have a Stern layer near the interface. Form. Thereby, 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 is irradiated with visible light or the like, photocatalytic activity that fully utilizes the ability of the photocatalyst is obtained. In other words, if an attempt is made to produce a photocatalytic film without using a negatively charged substance, many photocatalytic particles will be located in the resin, and even if the photocatalytic film is irradiated with visible light or the like, electrons will jump out to the vicinity. Cannot be obtained and sufficient photocatalytic activity cannot be obtained.

  The negatively charged substance according to the present embodiment may have a lower pH limit of about 7. This is because below this value, the photocatalyst coating solution 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 solution becomes white turbid, and a photocatalytic film having translucency cannot be obtained. In other words, when the photocatalyst film according to the present embodiment does not need to have translucency, the pH of the negatively charged substance may exceed 9.

  In the negatively charged substance according to this embodiment, the lower limit of the particle size with an average primary particle size is 1 nm, preferably 5 nm. This is because the storage stability of the photocatalyst coating solution tends to decrease as the particle size decreases, and if it is less than 1 nm, it is difficult to ensure the storage stability of the photocatalyst coating solution according to the present embodiment. In other words, when the photocatalyst coating solution is used without being stored for a long period of time after production, a negatively charged substance having a particle size smaller than the above can be employed. The measurement of the primary particle size of negatively charged substances is described in G. W. Sears, Jr. By using the Sears method described in "Analytical Chemistry 28, 1981-1983 (1956)".

  The upper limit of the particle size of the negatively charged substance is 400 nm, preferably 100 nm, and more preferably 50 nm. This is because the transparency of the photocatalytic film decreases as the particle size increases. In other words, when the photocatalytic film according to the present embodiment does not have to be translucent, 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.

  The negatively charged substance that satisfies the above requirements can be used in the form of an aqueous dispersion, whether it is acidic or basic. What type of negatively charged substance is used may be appropriately selected according to the photocatalyst-containing body to be mixed and the stable region of the resin.

[Method for producing photocatalyst coating solution]
As described above, each of the photocatalyst-containing bodies produced, the resin, and the negatively charged substance are mixed. Specifically, first, a negatively charged substance is charged into the photocatalyst-containing body while stirring the photocatalyst-containing body at, for example, about 100 rpm to 700 rpm.

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

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

  The stirring time depends on the charging rate of the resin with respect to the photocatalyst-containing body containing the negatively charged substance, but at room temperature, for example, about 20 kL with respect to the photocatalyst-containing body containing about 40 kL of the negatively charged substance. When the resin is added, it may be about 20 minutes.

  A metal such as Ag, Cu, or 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, sputum and algae attached to the surface even in the dark, and thus can further improve antibacterial properties. The amount added may be about 1 wt% to 5 wt%.

  A platinum group metal 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 degradability of organic contaminants and the decomposability of harmful gases and odors. The amount added may be about 1 wt% to 5 wt%.

[Coating method of photocatalyst coating solution]
The photocatalyst coating liquid which concerns on this embodiment can form the photocatalyst coating film which has high hydrophilicity by coating on the surface of various base materials, and making it harden | cure. The substrate is not particularly limited as long as a photocatalytic coating film can be formed. Examples of the base material include various materials such as wood, organic materials including paper, inorganic materials including metal, and mixtures or compounds thereof.

  Examples of organic materials include vinyl chloride resin, polyethylene, polypropylene, polycarbonate, acrylic resin, polyacetal, fluorine resin, silicone resin, ethylene-vinyl acetate copolymer (EVA), acrylonitrile-butadiene rubber (NBR), polyethylene terephthalate ( PET), ethylene-vinyl alcohol copolymer (EVOH), polyimide resin, polyphenylene sulfide (PPS), acrylonitrile-butadiene-styrene (ABS) resin, synthetic resin material such as melamine resin, natural, synthetic or semi-synthetic fiber material In particular, it is preferable to use a product made of polyvinyl chloride having a good balance in weather resistance, strength and price. Moreover, it is preferable to use the base material which is opaque and has concealment performance from the property of the temporary enclosure. These may be commercialized into a required shape and configuration such as a photocatalyst film, other molded products, and laminates.

  When the base material is made of an organic material, it is preferable that the base material is surface activated in advance. This treatment improves the wettability and coating properties of the photocatalyst coating liquid according to the present embodiment to the substrate. 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, or the like can be used.

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

[Method for producing photocatalytic film]
Below, the method to manufacture the photocatalyst film which concerns on this embodiment is demonstrated. The photocatalyst film according to the present embodiment is selected and selected under the condition that the thickness of the resin film serving as the base material is in the range of, for example, 10 μm to 300 μm, preferably 50 μm to 250 μm, more preferably 50 μm to 150 μm. On the surface of the base material, the photocatalyst coating solution is applied to the film production apparatus on the condition that the thickness is, for example, 0.1 μm to 100 μm, preferably 0.1 μm to 50 μm, more preferably 0.1 μm to 5.0 μm. Apply to.

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

  Subsequently, the film production apparatus base coated with the photocatalyst coating liquid is conveyed into a drying furnace, and is heated and dried by hot air drying, a far infrared heater, a panel heater or the like, thereby curing 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 solution under the condition that the thickness of the photocatalyst film falls within the above range is that the photocatalytic activity as a photocatalyst film cannot be sufficiently obtained when the coating thickness is lower than the lower limit. On the other hand, if the above upper limit is exceeded, the photocatalyst film or the precursor during production thereof may be peeled off from the film production equipment table, cracked, or warped, resulting in a decrease in durability of the thin film. This is to do.

[Attaching method of photocatalytic film to shroud]
In the present embodiment, a photocatalyst coating liquid to be a photocatalyst film is provided on one surface of a polyvinyl chloride film or the like so that the photocatalyst film can be easily attached to the shroud. An adhesive layer is provided on the other surface, and the surface of the adhesive layer is covered with a release paper or release film of silicone or other release agent.

  If it carries out like this, when sticking a photocatalyst film with respect to a surrounding board regardless of a place, a release paper etc. can be taken and an adhesive layer can be stuck to a surrounding board. However, the photocatalytic film according to the present embodiment is not necessarily provided with release paper or the like, and thus can be directly applied to a substrate such as paper.

Here, in the production of the adhesive layer, various resins such as a solvent type, an emulsion type, a solventless acrylic type, a rubber type, a urethane type, or a silicone type are used. Any one of these or a mixture of some of them is applied to 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, or the like can be used. The coating speed may be 1 mpm to 100 mpm, preferably 10 mpm to 70 mpm. Further, coating ^{amount, 10g / m 2 dry~300g / m} 2 dry, may be preferably a condition to be ^{20g / m 2 dry~60g / m 2} dry.

  Subsequently, the release paper coated with the above-mentioned various resins is conveyed into a drying furnace and cured by hot air drying, 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 photocatalytic film according to the present embodiment, as will be described in each example described later,
(1) Since it has excellent adhesion, it has the advantage that it is generally difficult to peel off from a polyvinyl chloride film, etc., which is difficult to ensure adhesion, even if an external force is applied during transportation of the shroud, etc. Hard to peel off,
(2) In addition, because it has an excellent ability to decompose organic matter, it can effectively purify air and is also a visible light responsive type, so it can be used not only for fences used at outdoor construction sites, but also indoor construction sites. It is also suitable as a shroud used in
(3) Since the hydrophilicity of the photocatalyst is observed and the self-cleaning property is excellent, it is of course suitable for use at an outdoor construction site.
(4) Since the coating film of the photocatalyst is hardly deteriorated, there are advantages in terms of adhesion and outdoor use.

  The enclosure plate of this embodiment is good to replace the photocatalyst film on the surface regularly or irregularly, for example. Thereby, even if the photocatalyst film is somewhat peeled off due to use, it can be returned to a new state. This is also an advantage that cannot be obtained in the case of a type of shroud type shroud.

  Also, from a different perspective, in the case of the type of shroud-type shroud, the shroud is cleaned regularly or irregularly, dried, transported to the painting site as necessary, and repainted. Various operations are required. On the other hand, the photocatalytic film can be easily replaced, the cost can be reduced, and the emission of carbon dioxide generated by using a transportation vehicle during transportation can be reduced. .

  In addition, the application object of a photocatalyst film is not limited to a polyvinyl chloride film, It is various resin films as described in an Example, It is other resin films, Furthermore, a metal etc. should be included. Needless to say.

  Although the resin film will be described as examples of the shroud 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 example, first, a photocatalyst coating liquid (TPX-FxFC manufactured by Sakai Corporation) and isopropyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd.) are blended at a ratio of, for example, 100: 55 to 75. In addition, the surface activation treatment is performed by applying the isopropyl alcohol as a base material to the surface of the base material, and the adhesion to the photocatalyst coating solution containing the isopropyl alcohol is increased. Then, for the polyvinyl chloride film substrate (manufactured by Towa Gosei Kogyo Co., Ltd.), the direct gravure coating method, the application amount is, for example, 10 g / m ² dry to 50 g / m ² wet, and the drying temperature is, 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)
The present embodiment is different from the first embodiment only in that the surface activation treatment is not performed. That is, in this example, a photocatalyst coating liquid (TPX-FxFC manufactured by Sakai 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 polyvinyl chloride film substrate ( 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
In contrast to 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 performed. That is, in this example, a photocatalyst coating liquid (TPX-FxFA manufactured by Sakai 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 substrate ( 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
The present embodiment is different from the first embodiment in various points. That is, in this example, a photocatalyst coating liquid (TPX-FxFA made by Sakai Corporation) and isopropyl alcohol were blended at a ratio of about 100: 65, and a vinyl chloride film base material (manufactured by Towa Gosei Kogyo Co., Ltd.) For example, the coating process was performed by hand coating under the conditions of 20 g / m ² , a drying temperature of 100 ° C., and a drying time of 5 minutes, for example.

(Comparative Example 1)
As this comparative example, a vinyl chloride film base material (manufactured by Towa Gosei Kogyo Co., Ltd.) that was not subjected to the coating treatment of the photocatalyst coating solution 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 point that isopropyl alcohol is not blended in the photocatalyst coating liquid, and the surface activation treatment were performed. The difference is not. That is, in this comparative example, the photocatalyst coating liquid (manufactured by TPX-FxFC鯤Corporation), relative to vinyl chloride film substrate (manufactured by Towa Gosei Co., Ltd.), hand painted with 20 g / ^{m 2,} the drying temperature 100 ° C. The coating treatment was performed under the condition that the drying time was 5 minutes.

  Next, a photocatalyst film having a thickness of 1 μm was formed by the method described in the embodiment using the photocatalyst coating liquid of each example and each comparative example. About these photocatalyst films, the following items were measured or evaluated, respectively.

1. Appearance evaluation of appearance 1. Decomposition activity: Evaluation of decomposition activity according to JIS R1703

  In addition, about the decomposition activity, since the titanium oxide used for this coating liquid had visible light responsiveness, it replaced with irradiating with ultraviolet light, and irradiated visible light.

Table 1 summarizes various preconditions and measurement results of the above-described examples and comparative examples.

First, consider a comparative example.
In Comparative Example 1, since the photocatalyst coating solution was not applied to the polyvinyl chloride film substrate, the decomposition activity was -0.07. That is, it can be seen that the photocatalytic activity such as decomposition activity cannot be obtained in Comparative Example 1.

  In Comparative Example 2, although the photocatalyst coating liquid is applied to the polyvinyl chloride film substrate, isopropyl alcohol is not blended in the photocatalyst coating liquid. For this reason, the photocatalyst coating liquid did not sufficiently wet and spread with respect to the polyvinyl chloride film substrate, and as a result, a desired photocatalyst coating film was not formed on the polyvinyl chloride film substrate. Therefore, it can be seen that the result of Comparative Example 2 does not result in the desired photocatalytic action.

  On the other hand, none of Examples 1 to 4 showed any abnormal appearance, and an excellent decomposition activity effect could be confirmed. In other words, if the decomposition activity is a numerical value of 5.0 or more, it can be said that there is a predetermined self-cleaning performance set by the photocatalyst industry association, so that all of the examples have self-cleaning performance. Will be.

  In addition, in Example 1, since the surface activation treatment is performed, it can be seen that higher decomposition activity can be obtained as compared to Example 2 that is not. However, in Example 3, surface activation treatment is not performed, but it can be seen that higher decomposition activity than that in Example 2 can be obtained by changing the type of the photocatalyst coating liquid. Further, in Example 4, the surface activation treatment was not performed, but depending on the type of the photocatalyst coating solution, a high decomposition activity can be obtained by using a blend of isopropyl alcohol at a ratio suitable for this. I understand that.

In this example, isopropyl alcohol was used as an example of the solvent to be blended in the photocatalyst coating solution, but the solvent is not limited to this, and ethanol, water, and the like can also be used.

Claims (8)

  A nano-order photocatalyst particle, a negatively charged substance having a zeta potential of −30 mV to −70 mV repelling each other in the solvent containing the photocatalyst particle, and an uncured resin A shroud to which a photocatalyst film obtained by curing a photocatalyst coating solution is attached. The photocatalyst particles are 3 wt% to 70 wt% with respect to the photocatalyst film produced using the photocatalyst coating solution,
The negatively charged substance is 19 wt% to 80 wt% with respect to the photocatalyst film produced using the photocatalyst coating solution,
The shroud according to claim 1, wherein the resin is selected from 3 wt% to 60 wt% with respect to a photocatalyst film manufactured using a photocatalyst coating solution.   The enclosure plate according to claim 1, wherein the negatively charged substance has a pH of 7 or more and 9 or less.   The shroud according to claim 1, wherein the negatively charged substance has an average primary particle diameter of 1 nm or more and an average secondary particle diameter of 4000 nm or less.   The shroud of claim 1, wherein the negatively charged material includes silica.   The enclosure plate according to claim 1, wherein the resin includes any one of an acrylic resin, a silicone resin, a silicone resin, and a urethane resin.   2. The shroud according to claim 1, wherein the photocatalyst particles are photocatalyst particles in which flat crystal particles and solid crystal particles having a thickness larger than that are combined. A photocatalytic film for a shroud, wherein the photocatalyst coating liquid according to claim 1 is cured.