JP5045979B2 - UV cut filter, tube and lighting fixture - Google Patents

Description

  The present invention relates to an ultraviolet cut filter, a tube, and a lighting fixture that cut at least ultraviolet light and transmit yellow light or red light.

  2. Description of the Related Art There are known illumination light sources and luminaires that are provided with a light cut filter that blocks (cuts) ultraviolet light and blue light and emits yellow to orange (orange) light. These light sources and luminaires are mainly used for low worming or clean room lighting that does not require ultraviolet and blue light.

Polyethylene terephthalate (PET) or acrylic (PMMA) in which a UV absorber such as titanium oxide (TiO ₂ ) or cesium oxide (CeO ₂ ) is added to the surface of a translucent material as a conventional lamp or lighting fixture for low insect repellent A configuration in which a resin filter such as is attached is known (see, for example, Patent Documents 1 and 2).

Further, as a lamp that suppresses the emission of ultraviolet rays, there is known a lamp with an ultraviolet cut filter in which an ultraviolet absorbing film mainly composed of zinc oxide (ZnO) fine particles having excellent durability and cost is formed on the outer surface of the bulb. (For example, refer to Patent Document 3).
Japanese Patent Laid-Open No. 10-21714 JP 2004-247156 A JP 2001-143657 A

  The UV cut filters of Patent Documents 1 and 2 can cut light with a wavelength of about 410 nm, but since they are resin filters, the heat resistant temperature is about 100 ° C. or less, and there is a problem with durability. is there.

  Moreover, since the ultraviolet cut filter like Patent Document 3 is mainly composed of zinc oxide (ZnO) fine particles that are inorganic oxides, it has excellent heat resistance and durability, but the cut wavelength is about 380 nm or less, It is difficult to cut light on the longer wavelength side.

  The present invention has been made in view of the above problems, and an object thereof is to provide an ultraviolet cut filter or the like that is excellent in durability and heat resistance and that can easily control ultraviolet and blue light absorption characteristics. To do.

In the ultraviolet cut filter according to claim 1, fine particles mainly composed of zinc oxide (ZnO) are doped with at least one kind of metal among indium (In), bismuth (Bi) and iron (Fe). A feature is that the concentration of the doped metal is decreased from the surface of the fine particle toward the center.
Moreover, it is comprised so that the 50% transmittance | permeability wavelength of the short wavelength absorption edge side may be set to 400-430 nm. “Transmittance on the short wavelength side absorption peak” is the transmittance of only the filter not considering the transmittance of the substrate on which the filter is formed, and is within the wavelength range of 400 to 650 nm, which is the short wavelength side region of visible light. This means the transmittance when the predetermined wavelength is changed so that the transmittance decreases as it approaches the short wavelength side.

  When fine particles containing zinc oxide (ZnO) as a main component are doped with indium (In) or the like, conductive semiconductor fine particles are formed, and the cut wavelength, which was originally about 380 nm or less, is shifted to the long wavelength side due to the addition of the conductivity. By configuring so that the concentration of the doped metal decreases toward the center of the fine particle part, it is possible to cut light with a wavelength of about 410 nm better than when the entire fine particle is doped with a uniform concentration. It became.

  The concentration of the dope metal with respect to the whole fine particles is 2 to 30% by mass, preferably 10 to 20% by mass, and the concentration on the surface side of the fine particles is preferably 50 to 100% by mass. .

  The fine particles include those in which the concentration of the doped metal is 0% by mass in the central region. The rate of decrease in density can be adjusted by the characteristics of UV-cutting. However, it is optimal that the rate of decrease is at a substantially continuous rate up to a depth of at least 10% of the particle diameter.

  A second aspect of the present invention is the ultraviolet cut filter according to the first aspect, wherein the doping amount of the doped metal is 3 to 20% by mass with respect to the fine zinc oxide (ZnO).

  If the doping amount is less than 3% by mass, it is impossible to cut light around 410 nm. Even if the doping amount exceeds 20% by mass, the effect of cutting light of around 410 nm is hardly changed, and the cut rate of light of 380 nm or less is lowered.

  [3] The ultraviolet cut filter according to [1] or [2], wherein the surface of the fine particles is mainly composed of an oxide of at least one of indium (In), bismuth (Bi) and iron (Fe). Is formed.

Zinc oxide (ZnO) is an amphoteric compound and has the disadvantage of poor chemical stability, such as being dissolved in an acid alkali or the like. In particular, when a semiconductor is doped with a metal, optical characteristics are easily affected by reacting with CO ₂ , SOx, NOx, etc. in the air.

  Therefore, a layer mainly composed of at least one kind of oxide of indium (In), bismuth (Bi), and iron (Fe) is formed on the surface of the fine particles. Since these metal oxides have high chemical stability and hardly change optical characteristics, it is possible to improve the durability of the UV-cut material. Use of an oxide of the same metal as the doped metal as the material used for the metal oxide layer is advantageous in terms of manufacturing and characteristics.

  The thickness of the metal oxide layer is 1.0 to 30 nm, preferably 3.0 to 10 nm. If the thickness of the layer is less than 1.0 nm, the effect of improving the durability cannot be sufficiently obtained, and if it exceeds 30 nm, the ultraviolet cut effect is impaired, which is not preferable.

According to a fourth aspect of the present invention, in the ultraviolet cut filter according to any one of the first to third aspects, silicon oxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), zirconium oxide (ZrO ₂ ) is formed on the outermost surface of the fine particles. Alternatively, a layer mainly containing at least one of yttrium oxide (Y ₂ O ₃ ) is formed.

Silicon oxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), zirconium oxide (ZrO ₂ ), or yttrium oxide (Y ₂ O ₃ ) is a material having excellent chemical stability, and a relatively thin film is formed. Since it is easy, the durability can be further improved by forming a layer on the outermost surface of the fine particles without significantly impairing the performance of ultraviolet ray cutting.

  The thickness of the metal oxide layer is 1.0 to 30 nm, preferably 3.0 to 10 nm. If the thickness of the layer is less than 1.0 nm, the effect of improving the durability cannot be sufficiently obtained, and if it exceeds 30 nm, the ultraviolet cut effect is impaired, which is not preferable.

  The ultraviolet cut filter according to any one of claims 1 to 4, wherein the fine particles are further doped with at least one of chlorine (Cl), bromine (Br), and fluorine (F). And

  By doping with indium (In) or the like, it is possible to set the transmittance 50% wavelength on the short-wavelength absorption edge side to 400 to 430 nm, but it is difficult to effectively cut light with a wavelength of 405 to 430 nm. is there. If even a small amount of this light is emitted, it may be undesirable depending on the application, for example, it may attract insects.

  Therefore, in addition to at least one of indium (In), bismuth (Bi) and iron (Fe), at least one of chlorine (Cl), bromine (Br) or fluorine (F) is further doped. It has become possible to increase the cut rate at a wavelength of 400 to 430 nm. Although the cause of the high cut rate at a wavelength of 400 to 430 nm is not clarified, a specific substance of the conductive semiconductor fine particles can be obtained by further doping with chlorine (Cl), bromine (Br) or fluorine (F). This is probably because the characteristics of the cut wavelength change due to the substitution.

  The ultraviolet cut filter according to any one of claims 1 to 4, wherein the fine particles are further doped with at least one of copper (Cu), silver (Ag), and cobalt (Co). And

  By doping with indium (In) or the like, it is possible to set the transmittance 50% wavelength on the short-wavelength absorption edge side to 400 to 430 nm, but it is difficult to effectively cut light with a wavelength of 405 to 430 nm. is there. If even a small amount of this light is emitted, it may be undesirable depending on the application, for example, it may attract insects.

  Therefore, in addition to at least one of indium (In), bismuth (Bi) and iron (Fe), at least one of copper (Cu), silver (Ag) or cobalt (Co) is further doped. It has become possible to increase the cut rate at a wavelength of 400 to 430 nm. The cause of the increase in the cut rate at a wavelength of 400 to 430 nm has not been clarified, but the conductivity of the conductive semiconductor fine particles is changed by doping with copper (Cu), silver (Ag), or cobalt (Co). This is thought to be due to the fact that the characteristics of the cut wavelength change.

  The ultraviolet cut filter according to claim 7 is formed on the surface of the translucent substrate with a film thickness of 0.05 to 10 μm.

  The base material has optical characteristics that transmit visible light, and examples of the material include glass and resin.

  The structure of the ultraviolet cut filter is not particularly limited as long as it has a predetermined ultraviolet cut function. However, in order to transmit light other than the wavelength to be cut while cutting desired light, the film thickness is 1. It is preferable to be in the range of 0 to 5.0 μm.

The tube of claim 8 is provided with a translucent bulb containing a light emitting means; and the ultraviolet cut filter according to any one of claims 1 to 6 formed on a surface of the bulb. To do.

  A tube means an incandescent bulb, a halogen bulb, or a discharge lamp such as an HID lamp or a fluorescent lamp. The light emitting means refers to a filament in the case of an incandescent bulb and a halogen bulb, and refers to a discharge space (including a phosphor layer) in the case of a discharge lamp.

The lighting fixture according to claim 9 is formed on the surface of the cover ; a light source disposed in the tool body; a translucent cover disposed in the tool body so as to cover the light source; An ultraviolet cut filter according to any one of claims 1 to 6;

  The lighting fixture includes a ceiling-mounted fixture, a downlight, a translucent device, and the like, and the cover includes a glove in addition to a plate-like cover.

  According to the present invention, conductivity is imparted by doping in the fine particles mainly composed of zinc oxide (ZnO) with indium (In) or the like so that the doping concentration decreases toward the center of the fine particle part, and is originally about 380 nm. The cut wavelength which has been described below is shifted to the long wavelength side, and an ultraviolet cut material capable of satisfactorily cutting light having a wavelength of about 410 nm can be obtained.

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

  FIG. 1 is a schematic cross-sectional view of zinc oxide (ZnO) fine particles constituting the ultraviolet ray-cutting material in the first embodiment of the present invention.

As shown in FIG. 1, the zinc oxide (ZnO) fine particles 1 are substantially spherical and have a particle diameter of 10 to 100 nm, for example, about 70 nm. A coating layer 2 made of indium oxide (In ₂ O ₃ ) is formed on the surface of the fine particles 1. Coating layer 2, bismuth oxide _{(Bi 2 O} 3), it may be formed from iron oxide _(Fe 2 _{O 3).}

  Indium (In) is present as the doped metal M inside the zinc oxide (ZnO) fine particles 1. The abundance (concentration) is distributed so as to decrease toward the center of the fine particles 1. The doped metal M may be bismuth (Bi) or iron (Fe), but is preferably the same as the metal obtained by reducing the metal oxide constituting the coating layer 2 in relation to the doping treatment described later. .

In the case of indium (In), the amount of the doped metal M added to the zinc oxide (ZnO) fine particles 1 is 10 to 30% by mass in terms of oxide (In ₂ O ₃ ) with respect to the mass of the fine particles 1. . The surface has a concentration that is substantially rich in indium oxide (In ₂ O ₃ ) due to the coating layer 2, and is approximately 0% by mass at the center of the fine particles 1.

Next, the manufacturing method of an ultraviolet cut material is demonstrated. First, 12% by mass of indium chloride is dissolved in zinc oxide (ZnO) fine particles 1 in an ethanol dispersion in which 20% by mass of zinc oxide (ZnO) fine particles 1 having a particle diameter of about 70 nm as shown in FIG. Let Then, while stirring this dispersion, for example, a predetermined amount of formaldehyde, hydroquinone or the like is added as a reducing material to form a layer made of indium (In) as shown in FIG. . Next, the dispersion is applied to the surface of a plate-like translucent substrate made of Pyrex ( registered trademark ) glass by a flow coat or the like, and heat-treated in an air atmosphere at 300 to 500 ° C. for a predetermined time. By this heat treatment, as shown in FIG. 1C, indium (In) is thermally diffused inside the fine particles 1 and a coating layer 2 made of indium oxide (In ₂ O ₃ ) is formed on the outer surface of the fine particles 1. The An ultraviolet cut filter having a thickness of about 0.5 μm is formed on the substrate surface. Then, indium (In) is doped inside the fine particles 1 as a doped metal M so that the concentration decreases toward the center of the fine particles 1.

If necessary, at least one of silicon oxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), zirconium oxide (ZrO ₂ ), and yttrium oxide (Y ₂ O ₃ ) as the outermost layer of the fine particles 1 as a main component. A layer may be formed. Silicon oxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), zirconium oxide (ZrO ₂ ), or yttrium oxide (Y ₂ O ₃ ) is a material having excellent chemical stability, and a relatively thin film is formed. Since it is easy, the durability can be further improved without forming a layer on the outermost surface of the fine particles without significantly impairing the performance of ultraviolet rays.

  FIG. 2 is a graph showing the transmittance spectral distribution of the ultraviolet cut filter manufactured by the above manufacturing method. Since the transmittance shown in this graph is a value excluding the transmittance of the substrate, it substantially represents the transmittance spectral distribution of the ultraviolet cut filter. According to this spectral distribution, light (ultraviolet rays) up to a wavelength of 390 nm is cut almost 100%, and the transmittance at 405 nm is 30% or less. The transmittance 50% wavelength on the short wavelength absorption end side is about 430 nm. The average transmittance at a wavelength of 480 to 780 nm is 96%.

  As can be understood from the transmittance spectral distribution shown in FIG. 2, the ultraviolet cut filter of this embodiment has a function of effectively blocking (cutting) light on the short wavelength side of visible light.

Next, a second embodiment will be described. In the present embodiment, in addition to the doped metal M of the first embodiment, another doped metal (for example, silver (Ag)) is simultaneously doped into the fine particles 1. Specifically, 10 to 30% by mass of indium (In) in terms of oxide (In ₂ O ₃ ) with respect to the mass of fine particles 1, and 0.001 to 0.1% in terms of oxide (Ag ₂ O). % Silver (Ag) is doped. For example, a method in which an appropriate amount of silver nitrate is added to an aqueous solution of zinc compound such as zinc oxide (ZnO) fine particles or zinc acetate (Zn (CH ₃ COO) ₂ ) and indium nitrate is applied to the surface of the plate-like translucent substrate. It is possible to form an ultraviolet cut filter by applying it with a flow coat or the like and thermally decomposing it in an air atmosphere at 500 to 1000 ° C. In addition, an ultraviolet ray cut directly deposited by applying a solution containing a suitable amount of zinc oxide (ZnO) fine particles and an aqueous solution of silver nitrate to the surface of a plate-like translucent substrate by flow coating, etc. It is possible to form a filter.

  Thus, in addition to the indium (In) as the doped metal M, silver (Ag) coexists, so that it becomes possible to shift the transmittance of 50% wavelength on the short wavelength absorption end side to the long wavelength side. The effect of cutting light of 400 to 430 nm is greatly improved.

Next, a third embodiment will be described. In the present embodiment, in addition to the doped metal M of the first embodiment, another halogen element (for example, chlorine (Cl)) is simultaneously doped into the fine particles 1. Specifically, 10 to 30% by mass of indium (In) and 0.1 to 4.0% by mass of chlorine (Cl) in terms of oxide (In ₂ O ₃ ) are doped with respect to the mass of the fine particles 1. Has been. For example, a plate-shaped transparent solution is prepared by adding an appropriate amount of a predetermined concentration of hydrochloric acid (HCl) to an aqueous solution of zinc compound such as zinc oxide (ZnO) fine particles or zinc acetate (Zn (CH ₃ COO) ₂ ) and indium nitrate. It is possible to form an ultraviolet cut filter by applying it to the surface of the light-sensitive substrate by flow coating or the like and thermally decomposing it in an air atmosphere at 500 to 1000 ° C. Also, by applying an appropriate amount of zinc oxide (ZnO) fine particles and an aqueous solution of hydrochloric acid (HCl) at a predetermined concentration to the surface of the plate-like translucent substrate by flow coating or the like, and similarly performing a thermal decomposition treatment It is possible to form an ultraviolet cut filter deposited directly. Note that chlorine (Cl) alone is difficult to dope into zinc oxide (ZnO) fine particles, but by doping with indium (In) or the like, a halogen element such as chlorine (Cl) can also be doped.

Next, a fourth embodiment will be described. The present embodiment is characterized in that the step of thermally diffusing the doped metal inside the zinc oxide (ZnO) fine particles is performed by heat treatment of the solution. First, 12% by mass of indium chloride (InCl ₃ ) as an indium compound is dissolved in zinc oxide (ZnO) in an ethanol dispersion in which 20% by mass of zinc oxide (ZnO) fine particles having an average particle diameter of about 70 nm are dispersed. While stirring this solution, for example, a predetermined amount of a reducing agent such as formaldehyde and hydroquinone is added to form an In layer on the outer surface of the zinc oxide (ZnO) fine particles. And after sealing this solution in a heat-resistant pressure-resistant container, it heats at the temperature of 100-200 degreeC. By this heat treatment, the indium component diffuses from the In layer into the inside of the zinc oxide (ZnO) fine particles while being dispersed in the solution, and the amount of the dope is reduced to the center of the fine particle portion. In this embodiment, indium chloride is used as the compound of the doped metal, but other compounds may be used as long as the metal layer can be formed on the outer surface of the fine particles. Further, instead of the indium compound, a layer containing bismuth or iron as a doped metal may be formed using a bismuth compound or an iron compound, and heat treatment may be performed in a solution.

  Next, a fifth embodiment will be described. The present embodiment is characterized in that the step of thermally diffusing the doped metal inside the zinc oxide (ZnO) fine particles is performed by heat treatment of the solution. First, 15 mass% of indium fine particles having an average particle diameter of 3 to 70 nm are dispersed with respect to zinc oxide (ZnO) fine particles in an ethanol dispersion in which 20 mass% of zinc oxide (ZnO) fine particles 1 having an average particle diameter of about 70 nm are dispersed. Indium fine particles are attached to the outer surface of zinc oxide (ZnO) fine particles to form an In layer. And after sealing this solution in a heat-resistant pressure-resistant container, it heats at the temperature of 100-200 degreeC. By this heat treatment, the indium component diffuses from the In layer into the inside of the zinc oxide (ZnO) fine particles while being dispersed in the solution, and the amount of the dope is reduced to the center of the fine particle portion. In the present embodiment, indium fine particles are used, but fine particles to be attached to the outer surface of zinc oxide (ZnO) fine particles may be bismuth fine particles or iron fine particles.

In the fourth and fifth embodiments, a coating layer made of indium oxide (In ₂ O ₃ ) can be formed on the outermost layer of dispersed fine particles by heat treatment of the solution. With this coating layer, the durability of the fine particles can be improved.

Furthermore, the fine particle dispersion prepared in the fourth and fifth embodiments is applied to the surface of a plate-like light-transmitting substrate made of Pyrex ( registered trademark ) by a flow coat or the like, and in the atmosphere of 300 to 500 ° C. By performing heat treatment in an atmosphere for a predetermined time, an ultraviolet cut filter having a film thickness of 1.0 to 10 μm on the surface of the base material and an average transmittance of only the filter excluding the base material of 80% or more can be formed. .

  The ultraviolet cut material or the ultraviolet cut filter of the first to fifth embodiments can be applied to the formation of a filter such as a window glass for buildings or vehicles.

  FIG. 3 is a schematic front view showing a tube that is a fifth embodiment of the present invention. L2 is an HID lamp as a tube, and the HID lamp L2 is provided with an outer tube bulb 11 for protecting the arc tube 40. An E-shaped base 3 is attached to the outer bulb 11 as a power supply means that is electrically connected to the arc tube 40.

  The ultraviolet cut filter F of the first embodiment is formed on the outer surface of the outer tube bulb 11. The ultraviolet cut filter F absorbs ultraviolet rays and light having a wavelength of 400 to 430 nm among the light emitted from the arc tube 40 of the HID lamp L2, and cuts them effectively.

  In addition to the HID lamp L2, the ultraviolet cut filter F may be formed on the bulb inner surface or bulb outer surface of the fluorescent lamp. When forming on the bulb inner surface of the fluorescent lamp, the ultraviolet cut filter F may be formed on the inner surface of the glass bulb before the phosphor film is formed by the above method, and then the phosphor film may be formed.

1 is a schematic cross-sectional view of a light cut filter according to a first embodiment of the present invention. The graph which shows the transmittance | permeability spectral distribution of the light cut filter of FIG. The schematic front view which shows the tube which is the 5th Embodiment of this invention.

DESCRIPTION OF SYMBOLS 1 ... Substrate, 2 ... Light absorption coating, 3 ... Spherical oxide fine particle, 4 ... Silver coating, F ... Light cut filter, L2 ... HID lamp as tube

Claims (9)

  Fine particles mainly composed of zinc oxide (ZnO) are doped with at least one metal of indium (In), bismuth (Bi), and iron (Fe), and the concentration of the doped metal is centered from the surface of the fine particles. The ultraviolet cut filter characterized by being comprised so that the transmittance | permeability 50% wavelength of the short wavelength absorption edge side may be set to 400-430 nm with the ultraviolet cut material comprised so that it may fall as it goes to.   The ultraviolet cut filter according to claim 1, wherein the doping amount of the doped metal is 3 to 20 mass% with respect to zinc oxide (ZnO) of the fine particles.   3. The ultraviolet cut according to claim 1, wherein a film mainly comprising at least one oxide of indium (In), bismuth (Bi) and iron (Fe) is formed on the surface of the fine particles. filter. A layer mainly composed of at least one of silicon oxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), zirconium oxide (ZrO ₂ ), and yttrium oxide (Y ₂ O ₃ ) is formed on the outermost surface of the fine particles. The ultraviolet cut filter according to any one of claims 1 to 3, wherein the ultraviolet cut filter is formed.   5. The ultraviolet cut filter according to claim 1, wherein the fine particles are further doped with at least one of chlorine (Cl), bromine (Br), and fluorine (F).   5. The ultraviolet cut filter according to claim 1, wherein the fine particles are further doped with at least one of copper (Cu), silver (Ag), and cobalt (Co).   The ultraviolet cut filter according to any one of claims 1 to 6, wherein the ultraviolet cut filter is formed on the surface of the translucent substrate with a film thickness of 1.0 to 10 µm. A translucent bulb containing a light emitting means;
An ultraviolet cut filter according to any one of claims 1 to 6 , formed on the bulb surface ;
A tube characterized by comprising: An instrument body;
A light source disposed in the instrument body;
A translucent cover disposed on the instrument body to cover the light source;
An ultraviolet cut filter according to any one of claims 1 to 6 formed on the cover surface ;
The lighting fixture characterized by comprising.

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