WO2002053369A1 - Stain-resistant transparent laminate and production method therefor, translucent cover for lighting device - Google Patents

Abstract

A stain-resistant transparent laminate which comprises a laminate structure integrally formed by interposing a resin intermediate film between at least two transparent substrates and having a visible-light transmittance of at least 80% and a light transmittance at 380-nm wavelength of at least 10%, and a photocatalyst film formed on the outer surface of the laminate structure, and which decomposes and removes deposits and is hard to get stained; and a lighting device using this stain-resistant transparent laminate as a translucent cover.

Description

 Description Antifouling transparent laminate, method for producing the same, translucent cover for lighting device, and lighting device

 The present invention relates to an antifouling transparent laminate and a lighting device, and more particularly to an antifouling transparent laminate in which adhering substances are decomposed and removed and dirt is hardly adhered, and a translucent cover for the antifouling transparent laminate. And lighting equipment that is easy to maintain. Background art

 In recent years, various pollutants have been released into the atmosphere and adhere to various facilities, both outdoors and indoors, impairing their functions and causing dirt that impairs the appearance and landscape. For example, lighting devices such as road lights and floodlights installed outdoors can be used for dust, dust, oil, rubber, fiber, tobacco dust, tar, carbon particles, oil mist, or dust that floats in the atmosphere. It is exposed to various contaminants based on various chemical substances such as cetaldehyde, methyl mercaptan, hydrogen sulfide, ammonia, etc., and adheres to the surface, impairing its function and polluting the appearance. Lighting equipment installed indoors is also contaminated with oil, fiber, cigarette dust, and evening matter. For example, in recent years, lighting devices installed in places where vehicles frequently come and go, such as roads and tunnels, include carbon particles contained in automobile exhaust gas and incompletely burned oil emitted from diesel engine vehicles. If mist or the like adheres to the outer surface, especially to a light-transmitting cover that transmits light from the light source, the transmission of irradiation light is hindered, and the desired lighting efficiency cannot be obtained and the appearance is stained. You. In particular, lighting devices installed in tunnels have a drastic decrease in the amount of illuminating light due to the attachment of fouling substances.

Of these lighting devices, those installed at high places on roads or in tunnels are regularly cleaned to remove dirt attached to the surface when dust and dirt are attached. There is a need to. However, since these lighting devices are installed in high places or in dark places in tunnels, there is a problem that cleaning work requires a lot of labor and cost. Therefore, Japanese Patent Application Laid-Open Nos. Hei 9-251 8104, Hei 9-231 711, Japanese Patent Laid-Open No. Hei 9-171 707, Hei 9-213 13 0 No. 9 proposes a lighting device in which a photocatalytic film made of titanium dioxide is provided on the outer surface of a translucent cover or globe covering a light source.

 According to these lighting devices, contaminants adhering to the surface are decomposed and removed by photocatalysis, suppressing deterioration in lighting efficiency due to dirt, reducing the frequency of cleaning work, and reducing maintenance costs. It is thought that it can aim at.

 On the other hand, in lighting devices installed on roads and tunnels, the translucent cover that covers the light source is made of tempered glass.However, it is difficult to remove pebbles, gravel, and debris from falling objects on the tires of passing vehicles. There is a problem that various objects collide due to splashing of pebbles or the like due to splashing or strong wind, and falling objects from a vehicle, and the light-transmitting cover is damaged and fragments are scattered.

 Therefore, the use of laminated glass that does not scatter fragments even if it is damaged by the collision of various objects is being studied as the translucent cover of these lighting devices. However, the conventional laminated glass is formed by integrally laminating an interlayer film made of polyvinyl butyral (hereinafter abbreviated as “PVB”) between two sheets of glass. Since this PVB is inferior in UV resistance, it contains a UV absorber as an essential component. Therefore, when a laminated glass using PVB as the intermediate film is used for the light-transmitting cover, the ultraviolet light from the light source is absorbed in the intermediate film, and even if the photocatalytic film is provided on the outer surface, the photocatalytic film can be used. However, there is a problem that the photocatalysis of the photocatalyst cannot be sufficiently exerted due to insufficient irradiation of ultraviolet rays.

 Therefore, a first object of the present invention is to prevent contamination and the like adhering to the surface from being decomposed and removed, making it difficult for dirt to adhere, and for preventing debris from scattering even if a part of the substance is damaged by a collision of a scattered substance. It is an object of the present invention to provide a transparent laminate.

 Further, a second object of the present invention is to provide the antifouling transparent laminate having excellent durability.

Further, a third object of the present invention is to use the antifouling transparent laminate as a light-transmitting cover and to prevent dirt from sticking, thereby reducing costs required for cleaning work and the like, Shards are not scattered even by damage due to collision, so maintenance is easy, An object of the present invention is to provide a lighting device suitable for lighting on roads and tunnels. Disclosure of the invention

 The present invention provides a laminated structure formed by integrating a resin intermediate film between at least two transparent substrates, and a photocatalytic film formed on at least one outer surface of the laminated structure. The laminated structure has a visible light transmittance of at least 80% and a light transmittance at a wavelength of 380 nm of at least 10%. A transparent transparent laminate is provided. The visible light transmittance in the present invention is a visible light transmittance defined in JISR310. BRIEF DESCRIPTION OF THE FIGURES

 FIG. 1 is a schematic sectional view showing one embodiment of the antifouling transparent laminate of the present invention. FIG. 2 is a perspective view showing an embodiment of the lighting device of the present invention.

 FIG. 3 is a diagram showing a spectral transmission characteristic according to Example 1 of the present invention.

 FIG. 4 is a diagram illustrating a spectral transmission characteristic according to Example 4 of the comparative example.

Explanation of reference numerals

 1 Antifouling transparent laminate

 2 Transparent substrate

 3 Transparent substrate

 4 Interlayer

 5 Photocatalytic film

 2 1 Lighting equipment for tunnel

 2 2 Main unit

 2 4 Lid

 2 5 back

 2 6 Mounting bracket

 2 7 Irradiation window

 2 8 Translucent cover

2 9 Seal member 3 0 High pressure sodium lamp

 3.1 Best Mode for Carrying Out the Invention

 The visible light transmittance of the laminated structure according to the present invention is preferably 85% or more (90% or less in actual production). The light transmittance at a wavelength of 380 nm in the present invention is preferably 50% or more (60% or less in actual production), measured in accordance with IS0950.

 The resin interlayer (hereinafter simply referred to as “interlayer”) is preferably a transparent membrane mainly composed of a trisocyanurate polymerized crosslinked ethylene-vinyl acetate copolymer.

 Further, the present invention is a lighting device having a light source for irradiating a light beam having a wavelength of 300 nm or more, and a translucent power bar covering the light source,

 An illumination device is provided in which the translucent cover is formed of an antifouling transparent laminate in which a photocatalytic film is disposed on the outside.

 In the present invention, the laminated structure includes at least two, or three or more transparent substrates sandwiching the intermediate film, and the adjacent transparent substrates are bonded and integrated via the intermediate film. A photocatalytic film is disposed on at least one outer surface of the multilayer structure. The photocatalyst film may be provided on both surfaces or only one surface of the outer surface of the multilayer structure.

The transparent substrate may be made of any transparent material as long as the visible light transmittance and the transmittance at a wavelength of 380 nm fall within the above-mentioned ranges by forming a laminated structure together with the intermediate film. There is no particular limitation. Further, at least two or more transparent substrates may be made of one kind of transparent material or two or more kinds of transparent materials. Specific examples of the transparent substrate include soda lime glass and alkali-free glass. And the like, or an inorganic transparent substrate made of tempered glass or the like, or an organic transparent substrate made of polycarbonate resin, acryl resin, or the like. In particular, when the antifouling transparent laminate of the present invention is used for a lighting device installed in a tunnel, a glass substrate made of soda lime glass, non-alkali glass, or An inorganic transparent substrate made of tempered glass or the like obtained by tempering it is preferable. Further, from the viewpoint of weight reduction, an organic transparent substrate made of a polycarbonate resin, an acrylic resin, or the like is preferable.

 The intermediate film is interposed between the transparent substrates to bond the transparent substrates to each other and to form a laminated structure having a light transmittance of 10% or more at a wavelength of 380 nm as the entire laminated structure. Any material may be used as long as it is a transparent film, and there is no particular limitation.Because it is excellent in ultraviolet light resistance, it can be interposed between transparent substrates without a UV absorber and transparent with desired adhesive strength. Substrates can be adhered to each other, and because of their high transmittance at wavelengths of 400 nm or less, crosslinked triisocyanurate (hereinafter referred to as “EVAT”) of ethylene-vinyl acetate copolymer. Is abbreviated).

 This E VAT is considered to have a structure in which a polymer of triaryl isocyanurate is crosslinked between molecular chains composed of an ethylene-vinyl acetate copolymer (EVA). The polymer is reacted with triaryl isocyanurate in the presence of a polymerization initiator or by irradiation with an electron beam or α-ray, etc., so that the triaryl isocyanurate undergoes radical polymerization and, at the same time, reacts with the triaryl isocyanurate. It reacts with the molecular chain of the ethylene-vinyl acetate copolymer, and has a structure in which the polymer of triaryl isocyanurate is intertwined with the molecular chain of the ethylene-vinyl acetate copolymer.

 Compared to EVA, E VAT is superior in adhesion to transparent substrates (especially glass substrates), so that an antifouling transparent laminate with excellent resistance to peeling and excellent durability can be obtained.

The ethylene-vinyl acetate copolymer, which is a component of E VAT, preferably has a vinyl acetate content of 15 to 50% by mass relative to the ethylene-vinyl acetate copolymer, and particularly preferably 19 to 40% by mass. % By mass. When an ethylene-vinyl acetate copolymer having a vinyl acetate content of less than 15% by mass is used, sufficient transparency cannot be obtained when cross-linked and cured at a high temperature, and ethylene-vinyl acetate copolymer exceeding 50% by mass is not obtained. The use of coalescence provides good transparency, but reduces the modulus and increases the tackiness, making it impossible to form a film. Therefore, it is most preferable that the vinyl acetate content is 22 to 30% by mass, and that the EV having high elasticity and high transparency which does not stick to each other is high. An AT film is obtained.

 In the E VAT, the proportion of triaryl isocyanurate in the ethylene-vinyl acetate copolymer is 0.5 to 20 parts by mass based on 100 parts by mass of the ethylene-vinyl acetate copolymer. Preferably, it is 1 to 5 parts by mass. When the amount of triallyl isocyanurate is less than 0.5 part by mass, the transparency is reduced, and when it exceeds 20 parts by mass, elongation is decreased, which is not preferable. In addition, it is preferable to add a silane coupling agent to the intermediate film in order to improve the adhesive strength between the intermediate film mainly composed of EVAT and the transparent substrate. Known silane couplings ^! Include, for example, archloropropylmethoxysilane, pinyltrichlorosilane, vinyltriethoxysilane, vinyltris () 3-methoxymethoxy) silane, r-methacryloxypropyltrisilane Methoxysilane, β- (3,4-ethoxycyclohexyl) ethyltrimethoxysilane, glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, a-mercaptopropyltrimethoxysilane, a- And aminopropyltriethoxysilane, N-j3- (aminoethyl) -aminopropyltrimethoxysilane, and the like.

 The amount of these silane coupling agents to be added is 5 parts by mass or less based on 100 parts by mass of both the ethylene vinyl acetate copolymer and the triaryl isocyanurate.

 If necessary, a polymerization inhibitor such as hydroquinone, quinone methyl ether, p-benzoquinone, or methylhydroquinone may be added to the interlayer in an amount of 5 mass% for the purpose of improving stability, in the same manner as the silane coupling agent. Parts or less can be added.

 Further, a coloring agent, an ultraviolet absorber, an antioxidant, a discoloration inhibitor and the like can be added in a range where the visible light transmittance does not become less than 80%.

 It is preferable that the thickness of the intermediate film is sufficient to adhere the transparent substrates to each other with a predetermined strength and to prevent the laminated glass from falling off and scattering when the laminated glass is broken.

The photocatalytic film is a film containing a substance having a photocatalytic action as a main component, or a film made of the substance in a form in which particles are dispersed. In the present invention, having photocatalytic action A substance is a semiconductor substance that receives ultraviolet light, absorbs its energy, ionizes to generate electrons and holes, and performs an oxidation or reduction action.

The substance used as a photocatalyst, eg, T I_〇 _{2, ZnO, Sn0 2, W0} 3, L aRh0 3, B i 2 0 3, F e T i 0 3, F e 2 0 3, CdF e 2 0 _{4, S r T i 0 3} , CdS e, GaAs, CaP, C E_〇 _{2, Tb0 2, Mg 0,} E r 2 0 3, Ru0 2 , and the like. These may be used alone or in combination of two or more. Further, a metal or metal oxide such as Pt ;, Rh, Nb, Cu, Sn, or NiO may be added to these substances.

 Above all, a transparent film containing titanium oxide (particularly, anatase-type titanium oxide) as a main component is preferable because it has high photocatalytic activity. The photocatalytic film may be formed by any method such as a sol-gel method, a CVD method, and a PVD method, and may be formed by other methods. The photocatalyst film may be formed only on one outer surface of the laminated structure, or may be formed on both outer surfaces. For example, after a titanium alcoholate solution is prepared by dissolving an organic titanium compound as a main component and a solvent such as alcohol, the solution can be formed by applying it to the surface of a transparent substrate and firing it.

 The thickness of the photocatalytic film is not particularly limited, and is usually about 0.005 to 0.5 m.

In addition, it is preferable to have an intermediate adhesive layer containing SiO ₂ as a main component between the photocatalytic film and the transparent substrate in order to prevent the diffusion of Na of soda lime glass. The bonding intermediate layer can be formed using, for example, hexamethyldisilazane, hexamethylcyclotrisilazane, or the like. Further, from the viewpoint of photocatalytic activity increase, (oxides of tin and indium) Sn0 ₂ film or I TO between the photocatalyst film and the transparent substrate film may be formed.

 In the production of the antifouling transparent laminate of the present invention, a photocatalyst film is formed in advance on the surface of one transparent substrate, and the transparent substrate is placed with the photocatalyst film outside and an intermediate film in between. This step may be performed by a step of laminating the transparent substrates, or may be performed by forming a photocatalytic film on the surface of the outer transparent substrate after forming the laminated structure.

For example, two transparent substrates (a) and (b) are bonded together via an interlayer (c). Taking an example of an antifouling transparent laminate having a photocatalyst film on one surface of a three-layered laminated structure, first, a transparent substrate is formed into a predetermined shape, and then a pretreatment such as washing is performed. After the application, a laminate can be manufactured by the following method.

 (1) After forming a photocatalytic film on the surface of one transparent substrate (a), this transparent substrate (a) is placed on another transparent substrate (b) through an intermediate film (c). A method in which the photocatalyst films are laminated so that they are on the outside, and the transparent substrates (a) and (b) are bonded together via an intermediate film by pressure bonding to integrate them.

 (2) A method in which a transparent substrate (b), an intermediate film (c) and a transparent substrate (a) are previously laminated and integrated to form a laminated structure, and then a photocatalytic film is formed on the transparent substrate (a). In particular, in an antifouling transparent laminated body having a laminated structure using a laminated glass using a glass substrate as the transparent substrate, first, in the middle or at the end of the process of manufacturing the laminated glass according to the following steps, By forming a photocatalyst film on the surface, an antifouling transparent laminate having a photocatalyst film on one surface of a three-layer structure in which two glass substrates are bonded and integrated via an intermediate film Can be manufactured

(a) The glass substrate is cut into a predetermined shape and dimensions, chamfered, and the surface is washed with a roll brush using hot water, a detergent, or the like to manufacture a glass substrate.

 (b) An interlayer film and other films or layers to be provided as necessary are sandwiched between two glass substrates.

 (c) Preliminary pressure bonding is performed in which the air between the interlayer film and the glass is degassed while heating and adhered to each other.

 (d) While applying heat and pressure, perform full pressure bonding for bonding between the interlayer film and the glass substrate.

For example, a photocatalytic film is formed on the surface of one glass substrate obtained in the step (a) ′, and this is pre-pressed with an intermediate film interposed on another glass substrate in the step (b) and thereafter. By performing the final pressure bonding, two glass substrates are bonded and integrated via an intermediate film so that the photocatalyst film is on the outside. A dirty transparent laminate can be obtained. In this method, The baking process in forming the photocatalytic film and the tempering vitrification process of the glass substrate can be performed simultaneously, and the glass substrate on which the photocatalytic film is formed (glass substrate in contact with the photocatalytic film) is a tempered glass antifouling transparent laminate. It is effective when manufacturing the body. In addition, a three-layer laminated structure in which two glass substrates are bonded and integrated via an intermediate film in advance through the steps (a), (b), (c), and (d) However, an antifouling transparent laminate can also be obtained by forming a photocatalytic film on one surface of the glass substrate. In this method, the photocatalytic film is formed at or near room temperature, and is easy to manufacture.

 The pre-compression bonding and the final compression bonding may be performed by either a two-stage bonding method, which is an independent step, or a single-stage bonding method, in which both steps are performed in one step. The type of interlayer film, the type of glass substrate, etc. Is appropriately selected according to the conditions.

 As the two-stage pressure bonding method, the following method may be mentioned.

(1) a first roll (pressing ^{force: 1. 8 X 10 5 P a} ), the heating oven (60 ° C), the second roll (pressing ^{force: 1. 8 X 10 5 P a} ), heated open (100) and the third roll (pressing force: 1. 8X 10 ⁵ P a) in this order, after the pre-compression bonding by thermocompression bonding the glass substrates sandwiching the intermediate membrane, autoclaved (130 ° C, 1. 27X 1 in 0 ⁶ P a), a method of performing the compression bonding (nipper roll method).

(2) Put the glass substrate sandwiching the interlayer film in a vacuum bag and heat it under reduced pressure (90 ° C, 8.38 x 10 ⁴ Pa) to degas the air present between the glass substrate and the interlayer film. , after preliminary bonding, O one Tokurebu (130 ° C, 1. 27 X 10 6 P a) to be had you, how to do this crimping (vacuum bag method).

The one-step bonding method, in a vacuum bag, placed glass substrate sandwiching the intermediate layer, (at ^{90, 8. 38 X 10 4 P} a) vacuum while heated between the glass substrate and the intermediate film exists This is a method in which pre-compression bonding, which degass the air to be deaerated, and main compression bonding, in which the pressure is reduced while heating to a higher temperature, are performed continuously.

An embodiment of the antifouling transparent laminate of the present invention will be described with reference to the drawings. The antifouling transparent laminate 1 whose schematic cross-sectional view is shown in FIG. 1 has a three-layer laminated structure in which an intermediate film 4 is interposed between a transparent substrate 2 and a transparent substrate 3 and bonded and integrated. Further, the transparent substrate 2 has a photocatalyst film 5 on the outer surface thereof. In this antifouling transparent laminate 1, the transparent substrate 2 on which the photocatalytic film 5 is formed is made of, for example, soda lime glass that has been subjected to a strengthening treatment with a thickness of 3 mm, and the transparent substrate 3 is made of, for example, 3 mm Consists of thick normal soda lime glass. The intermediate film 4 is, for example, a transparent film mainly containing a crosslinked polymer of triisocyanurate of ethylene-vinyl acetate copolymer, and the photocatalytic film 5 is, for example, a transparent film made of anatase-type titanium oxide. .

 Specific examples of the method for producing the antifouling transparent laminate of the present invention are, for example, as follows.

 A step of applying a coating solution for forming a photocatalyst film on a glass substrate, followed by baking to form a photocatalyst film, and a transparent film containing a triisocyanurate polymerized cross-linked ethylene monovinyl acetate copolymer as a main component. A step of laminating the glass substrate and another glass substrate through the step so that the optical catalyst film is exposed to form a laminated glass, wherein the visible light transmittance is 80% or more, and the wavelength 380 Produce an antifouling transparent laminate having a light transmittance in nm of 10% or more.

 Examples of the coating solution for forming a photocatalytic film include a coating solution in which titanium oxide fine particles are dispersed, and a titanium dioxide comprising a hydrolyzable titanium compound (for example, titanium alkoxide) and an organic solvent (for example, an alcohol solvent or an aromatic compound solvent). Precursor solution, and the like. As a titanium dioxide precursor solution composed of a hydrolyzable titanium compound and an aromatic compound solvent, the Electrochemical Society of Japan, Technical and Educational Transactions, vo 1.9 No. 1 (2000) 29-33, and Those described in 340757 and the like can be used.

 After the application of the coating solution, the coating solution is dried if necessary. Drying is performed, for example, under the conditions of about 100 to 400 ° C. for 10 to 50 minutes under an air atmosphere.

 The firing for forming the photocatalyst film is performed, for example, in an air atmosphere at 200 to 680 ° C. for 4 to 10 minutes. When baking is performed at a high temperature of 600 to 680 ° C, bending of a glass substrate and / or strengthening of a glass substrate can be performed simultaneously.

In the present invention, the photocatalyst film may be irradiated with ultraviolet rays after drying. Another glass substrate used to make a laminated glass is usually a photocatalytic film. A glass substrate having the same shape (thickness may be different) as the formed glass substrate is used. .

 In the antifouling transparent laminate 1 shown in FIG. 1, the light radiated from the light source disposed on the transparent substrate 3 side (the lower side on the paper surface of FIG. 1) transmits the transparent substrate 3, the intermediate film 4, and the transparent substrate 2. The transparent light reaches the photocatalyst film 5 after passing through the laminated structure composed of, and has a visible light transmittance of 80% or more and a light transmittance at a wavelength of 38 O nm of 10% or more. Visible light passes through the photocatalytic film 5 and is emitted to the outside of the laminate (upper side on the paper surface in FIG. 1) to become illuminating light, and ultraviolet light having a wavelength around 380 nm is a center. The photocatalytic action of the photocatalyst film 5 is exhibited, and contaminants adhering to the surface are oxidized, decomposed, and removed. Debris does not scatter even if a part is damaged by the collision of flying objects.

 Therefore, the antifouling transparent laminate of the present invention is suitable as a light-transmitting cover of a lighting device. In particular, if the laminated structure is made of laminated glass, it is suitable as a light-transmitting cover of a lighting device in roads and tunnels. It is.

 The present invention provides a light-transmitting cover for a lighting device using the antifouling transparent laminate of the present invention.

 A lighting device using the antifouling transparent laminate of the present invention as a light-transmitting cover has a light source and a light-transmitting cover that covers the light source. The light-transmitting cover can have various shapes and dimensions depending on the shape and the like of the lighting device.

 The light source is not particularly limited as long as it can emit visible light that is effective as an illumination light source and ultraviolet light having a wavelength of 300 to 400 nm that is effective for exhibiting photocatalysis. Specific examples of the light source include a high-pressure sodium lamp, a mercury lamp, a xenon lamp, a metal halide lamp, an incandescent lamp, and a fluorescent lamp. The light source may be not only a straight tube lamp but also an annular or compact lamp. From the viewpoint of brightness of illumination and photocatalytic activity, it is preferable to use a high-pressure sodium lamp.

Further, members or devices other than the translucent cover and the light source may be those used for this type of lighting device, and are not particularly limited. For example, a power supply device that supplies light-emitting power to a light source, a voltage stabilizing device for the power, a device housing, a frame, a mounting member, and a reflector installed behind the light source are similar to conventional lighting devices. Can be used Wear.

 Next, an embodiment of the lighting device of the present invention will be described by taking a tunnel lighting device shown in FIG. 2 as an example.

 The tunnel lighting device 21 shown in FIG. 2 includes a device main body 22 made of a corrosion-resistant casing, and a lid 24 attached to the front of the device main body 22 so as to be openable and closable. At the upper part of the rear surface 25, a mounting bracket 26 for fixing to a wall of a tunnel or the like is attached.

 An irradiation window 27 is opened at the center of the front surface of the lid 24. A translucent cover 28 is fitted into the irradiation window 27 through a sealing member 29 in a liquid-tight manner. ing. The translucent cover 28 is formed of a plate-shaped antifouling transparent laminate of the present invention, and has a photocatalytic film on the outer surface (the surface opposite to the lamp 30).

 A high-pressure sodium lamp 30 is detachably attached to a lamp socket (not shown) of the apparatus main body 21 so as to face the translucent cover 28. The high-pressure sodium lamp 30 emits visible light and light containing ultraviolet rays in a wavelength range of 300 nm to 400 nm.

 Further, a reflector 31 that optically faces the high-pressure sodium lamp 30 and reflects light emitted from the high-pressure sodium lamp 30 toward the irradiation window 27 is provided in the apparatus main body 21. It is arranged.

 In this lighting device, when the high-pressure sodium lamp 30 is turned on by supplying power and operating a ballast (not shown) for starting light provided in the device body 21, the high-pressure sodium lamp 30 is turned on. Thus, visible light and light containing ultraviolet light in the wavelength range of 300 nm to 400 nm are irradiated.

 The light emitted from the high-pressure sodium lamp 30 is reflected directly or by the reflector 31 to reach the light-transmitting cover 28, and the visible light passes through the light-transmitting cover 28, and Ultraviolet light is partially absorbed by the photocatalyst film and is irradiated into the tunnel. At this time, since the laminated structure and the photocatalytic film of the light-transmitting cover 28 transmit 80% or more of visible light, the inside of the tunnel is illuminated with sufficient brightness.

In addition, the lighting equipment installed in the tunnel is affected by dust and exhaust gas from automobiles, etc., and the dust or the like such as carbon, oil mist, Contaminants such as acetaldehyde, methyl mercaptan, hydrogen sulfide, and ammonia adhere. However, since a photocatalytic film is formed on the outer surface of the translucent cover 28, the outer surface of the translucent cover 28 is prevented from being soiled by the photocatalytic action of these photocatalyst films, and is less likely to be soiled. Alternatively, an effect of easily removing dirt once adhered is obtained, and a decrease in light transmittance due to dirt on the translucent cover 28 can be suppressed.

 Therefore, it is possible to effectively prevent such substances from adhering to the outer surface of the translucent cover 28, and prevent a decrease in the luminous flux irradiated through the translucent cover 28, thereby saving energy. It has an effect and does not require frequent cleaning such as wiping the translucent cover 28, thus facilitating maintenance. Debris does not scatter even if part is damaged by the collision of flying objects.

 Also, if a photocatalytic film is further formed on the inner surface of the translucent cover, the exhaust gas will enter the fixture, and the translucent cover will be damaged by the gas generated from the plastic or rubber in the fixture or hydraulic power. This has the advantage that the substance can be prevented from adhering to the inner surface. Furthermore, if a photocatalyst layer is formed around the main body 21 and the lid 24 and also on the reflector 31, as in the case of the translucent cover 28, it is not necessary to perform frequent cleaning, thereby facilitating maintenance. There is an advantage that can be.

 In addition, the present invention is not limited to the lighting device shown in FIG. 2, for example, a lighting device arranged in an emergency parking zone in a tunnel, a front cover of a headlight of an automobile, a front cover for a lamp of a traffic light, and the like. Of various lighting devices.

 Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto.

 (Example 1 )

 Prepare two soda lime glass substrates (visible light transmittance: 90.4%) with dimensions of 3 mm in thickness, 35 O mm in length and 1500 mm in width, and after chamfering, apply 40 ° The surface was cleaned with a roll brush using warm water C and a neutral detergent.

 A coating solution containing anatase-type titanium oxide particles is applied to the surface of one glass substrate, and dried with hot air at about 20 Ot in an air atmosphere, and heated to 63 to 65 ° C in an air atmosphere. After heating, it is rapidly cooled to form a photocatalytic film composed of an anatase-type titanium oxide (thickness: 0

(0.1 m) on one side was obtained. On another glass substrate, an E VAT (vinyl acetate content of ethylene monoacetate copolymer: 26%, triisocyanurate content: 5%) film (thickness)

: 0.4 mm), and the above tempered glass substrate was placed on the EVAT film so that the photocatalyst film was on the upper side, and the EVAT film was sandwiched between both substrates to prepare a pre-laminate. . The pre-laminate, the first roll (pressing force: 1. 85X10 ⁵ Pa), heating oven (60 ° C), the second roll (pressing ^{force: 1. 8 X 10 5 P a} ), heating oven (100 ° C) and the third roll (pressing force: 1. in order 8X 10 ⁵ Pa), after preliminary bonding, O one Tokure part (130 ° C, 1. Oite to 27 X 10 ⁶ P a) The glass laminate structure was manufactured by performing the final pressure bonding.

 (Example 2)

In the same manner as in Example 1, a pre-laminate was prepared by laminating a glass substrate, an EVAT film, and a tempered glass substrate with a photocatalyst, and the pre-laminate was placed in a vacuum bag and heated under reduced pressure (90 ° C, 8 ° C). . 38 X 10 ⁴ P a) to degassed air present between the glass substrate and the intermediate layer, after preliminary bonding, in an autoclave ^{(130, 1. 27X 1 0 6} P a), the crimping Was performed to produce a glass laminated structure.

 (Example 3)

 A glass laminated structure was manufactured in the same manner as in Example 1 except that the method for forming the photocatalytic film in Example 1 was changed as follows.

That is, on one surface of the glass substrate, after forming the S I_〇 ₂ film with a film thickness of 5 onm by reactive sputtering evening ring with S i target, titanium dioxide dissolved titanium butoxide in benzene solvent the precursor solution (electrochemical Society technical Education and research Journal vo l. 9 No. 1 (2000 ) 29~ 33) is applied to the S I_〇 ₂ film surface, an air atmosphere, 30 minutes at about 350 ° C It was dried, then baked at 630 for 20 minutes in an air atmosphere, and quenched to obtain a reinforced glass substrate having a photocatalytic film (film thickness: 120 nm) made of anatase-type titanium oxide on one side.

 (Example 4 (Comparative example))

 A glass laminated structure was manufactured in the same manner as in Example 1 except that a PVB film (thickness: about 0.38 mm) was formed instead of the EVAT film.

For the glass laminated structure obtained in Examples 1 and 4, an ultraviolet-visible spectrophotometer (Japanese The spectral transmittance in the wavelength region of 300 to 180 nm was measured using V570 manufactured by Hamamatsu Corporation. Figures 3 and 4 show the measured spectral transmission characteristics. The light transmittance at a wavelength of 380 nm of the glass laminated structure obtained in Example 1 was 77%, the light transmittance at 400 nm was 84.5%, and the visible light transmittance was 87. 5%. It should be noted that the glass laminated structure obtained in Example 2 also had the spectral transmission characteristics shown in FIG. Further, in Example 1, applying the silica sol prior to formation of the photocatalytic film and dried to form a coating film comprising the S I_〇 ₂ film, hereinafter, the photocatalytic film in the same manner as in Example 1 (thickness:. 0 0 1 xm) was obtained on one side to form a laminated glass structure, and the spectral transmission characteristics as shown in FIG. 3 were obtained.

 As a result of measuring the spectral transmittance of the glass laminated structure obtained in Example 3 in the same manner as described above, the light transmittance at a wavelength of 380 nm was 58.5%, and the light transmittance at a wavelength of 400 nm was The visible light transmittance was 63% and the visible light transmittance was 86%. Industrial applicability

 In the antifouling transparent laminate of the present invention, contaminants and the like adhering to the surface are decomposed and removed, and dirt is hardly adhered. Even if a part of the laminate is damaged by the collision of scattered substances, fragments are not scattered. Therefore, the antifouling transparent laminate of the present invention is suitable as a translucent cover for lighting devices installed on roads, tunnels, and the like.

 Further, according to the method of the present invention, the antifouling transparent laminate can be efficiently produced.

 In addition, the lighting device of the present invention uses the antifouling transparent laminate as a light-transmitting cover and is hardly stained, so that the cost required for cleaning work and the like is reduced, and the lighting device is damaged by collision of flying objects and the like. Since no debris is scattered, maintenance is easy and suitable for lighting in roads and tunnels.

Claims

The scope of the claims 1. A multilayer structure formed by integrating a resin intermediate film between at least two transparent substrates, and a photocatalytic film formed on at least one outer surface of the multilayer structure. A dirty transparent laminate, wherein the laminate structure has a visible light transmittance of 8 0% or more and the light transmittance at a wavelength of 380 nm is 10% or more. 2. The antifouling transparent laminate according to claim 1, wherein the resinous intermediate film is a transparent film containing a triisocyanurate polymerized crosslinked product of ethylene-vinyl acetate copolymer as a main component. 3. The antifouling transparent laminate according to claim 1, wherein the photocatalytic film is a transparent film containing titanium oxide as a main component.  4. The antifouling transparent laminate according to any one of claims 1 to 3, wherein the laminate is a three-layer laminated glass in which a transparent substrate in contact with a photocatalytic film is made of tempered glass. 5. A process for applying a coating solution for forming a photocatalyst film on a glass substrate, followed by baking to form a photocatalyst film, and mainly comprising a triisocyanurate polymerized bridge of ethylene-vinyl acetate copolymer. Laminating the glass substrate and another glass substrate via a transparent film so that the photocatalytic film is exposed to form a laminated glass, wherein the visible light transmittance is 80% or more; and A method for producing an antifouling transparent laminate having a light transmittance of 10% or more at a wavelength of 380 nm.  6. A light-transmitting cover for a lighting device, comprising the antifouling transparent laminate according to any one of claims 1 to 4.  7. A lighting device, comprising: a light source that emits light having a wavelength of 300 nm or more; and a light-transmitting cover that covers the light source,  The lighting device, wherein the light-transmitting cover is made of the antifouling transparent laminate according to any one of claims 1 to 4, wherein a photocatalytic film is disposed outside.