JP4161193B2 - Fluorescent glass and method for producing the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fluorescent glass and a method for producing the same.
[0002]
[Prior art]
Conventionally, fluorescent glass using rare earth elements has been known, and has been put to practical use, for example, as a fluorescent material for a lamp or a fluorescent material for a cathode ray tube. Examples of such fluorescent glass, for example, a glass component such as SiO ₂ or B ₂ O _3, glass composed of a rare earth element Tb ₂ O ₃ and Eu ₂ O _3, and has been known (for example, the following (See Patent Document 1 and Patent Document 2). Further, it is a glass containing phosphorus, oxygen, and fluorine, and a fluorescent phosphate glass containing Eu or Tb as a fluorescent agent, or a fluorescent phosphate fluorescent containing Eu, Tb, Sm, or Mn as a fluorescent agent. Glass is also known (see Patent Document 3 and Patent Document 4 below).
[0003]
However, the glass described in Patent Document 1 contains only up to 1.5 mol% of Eu ₂ O ₃ as a fluorescent agent, and the glass described in Patent Document 2 has Tb ₂ as a fluorescent agent. O _3, because only contains up to 1.5 mol%, sufficient fluorescence intensity can not be obtained at a concentration of Eu ₂ O ₃ or Tb ₂ O ₃ of this degree.
[0004]
Moreover, although the glass described in patent documents 3, 4 etc. contains many fluorescent agents, since it is a fluorinate glass, thermal durability and glass strength are small, and glass for fluorescent lamps or large sized glass It is difficult to produce a plate.
[0005]
[Patent Document 1]
Japanese Patent Publication No.57-27047 [0006]
[Patent Document 2]
Japanese Examined Patent Publication No. 57-27048 [0007]
[Patent Document 3]
Japanese Patent Laid-Open No. 8-133780
[Patent Document 4]
Japanese Patent Laid-Open No. 9-206422
[Problems to be solved by the invention]
The present invention has been made in view of the current state of the prior art described above, and its main purpose is to provide a glass having sufficient durability and strength, and further providing a fluorescent glass having excellent emission intensity. That is.
[0010]
[Means for Solving the Problems]
The present invention has been intensively studied to achieve the above-described object. As a result, according to the method in which a specific complex is used as the rare earth compound and this is introduced into the pores of the porous glass by the chemical vapor transport method, it has high emission intensity and transparency is not hindered. We have found that fluorescent glass with excellent properties can be obtained, and that fluorescent glass with sufficient durability and strength can be obtained by appropriately selecting a porous glass as a base material, and the present invention is completed here. It came to do.
[0011]
That is, this invention provides the following fluorescent glass and its manufacturing method. 1. A fluorescent glass in which a metal oxide containing a rare earth oxide is supported in the pores of a porous glass.
2. Item 2. The fluorescent glass according to Item 1, wherein the rare earth oxide is an oxide of at least one rare earth element selected from cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium and ytterbium. .
3. Base glass of the porous _{glass, SiO 2 -B 2 O 3 -Na} 2 O-Al 2 O 3 based glass containing SiO ₂ 55 to 80 wt%, SiO ₂ -B ₂ comprising SiO ₂ 35 to 55 wt% Item _3. The fluorescent glass according to Item 1 or 2, which is O ₃ —Na ₂ O glass or SiO ₂ —P ₂ O ₅ —Na ₂ O glass containing ₂₀ to 75% by weight of SiO ₂ .
4). Item 4. The fluorescent glass according to any one of Items 1 to 3, wherein the porous glass has a pore diameter of 2 to 50 nm.
5. A rare earth element β-diketonate complex is used as a raw material, the complex is introduced into the pores of the porous glass by a chemical vapor transport method, and the rare earth oxide is deposited in the pores. Item 5. A method for producing the fluorescent glass according to any one of Items 1 to 4.
6). Item 6. The method for producing a fluorescent glass according to Item 5, wherein a β-diketonate complex of at least one metal selected from alkali metals, alkaline earth metals and transition metals is further used as a raw material.
7). Item 7. The method for producing fluorescent glass according to Item 5 or 6, wherein one side of the porous glass is in a reduced pressure state, and a raw material gas accompanying the carrier gas is introduced into the pores from the other side.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The fluorescent glass of the present invention is obtained by supporting a metal oxide containing a rare earth oxide in the pores of a porous glass.
[0013]
Hereinafter, the fluorescent glass will be specifically described.
[0014]
Porous glass The porous glass used in the present invention is a glass having many through-holes. The composition of the porous glass is not particularly limited, and a glass having a known composition can be appropriately selected according to the purpose of use of the fluorescent glass, and the fluorescent glass has sufficient durability and strength depending on the application. Can be glass. Examples of such porous glass include silica-based porous glass A (matrix glass glass composition: SiO ₂ (55-80 wt%)-B ₂ O ₃ —Na ₂ O—Al ₂ O ₃ ), silica-based porous glass Glass B (matrix glass glass composition: SiO ₂ (35 to 55 wt%)-B ₂ O ₃ —Na ₂ O), silica-based porous glass C (matrix glass glass composition: SiO ₂ —B ₂ O ₃ —CaO— Al ₂ O ₃ ), silica-based porous glass D (matrix glass glass composition: SiO ₂ (20 to 75 wt%)-P ₂ O ₅ -Na ₂ O), silica-based porous glass E (SiO ₂ -B ₂ O ₃ -Na ₂ O-RO (R = alkaline earth, Zn), TiO ₂ porous glass (matrix glass glass composition: SiO ₂ -B ₂ O ₃ -CaO-MgO-Al ₂ O ₃ -TiO ₂ (TiO ₂ can be added up to 49.5 mol%)), rare earth-based porous glass (matrix glass composition: B ₂ O ₃ -Na ₂ O- (CeO ₂ , ThO ₂ , HfO ₂ , La ₂ O ₃ ))) It is done.
[0015]
In particular, those having silica-based porous glass A, the composition of B or D, _{i.e., SiO 2 -B 2 O 3 -Na} 2 O-Al 2 O 3 based glass containing SiO ₂ 55 to 80 wt%, SiO ₂ 35 to 55 wt% including _{SiO 2 -B 2 O 3 -Na 2} O -based glass, or _{SiO 2 -P 2 O 5 -Na 2} O system glass containing SiO ₂ 20 to 75% by weight, high transparency It is preferable in that it has.
[0016]
These glasses are known to undergo phase separation into two types of glass phases with different compositions by heat treatment. When the second phase generated by phase separation is dissolved and removed, the portion becomes voids. Thus, a porous glass having a large number of penetrating pores can be obtained.
[0017]
In the porous glass used in the present invention, the pore diameter is not particularly limited, but the preferred pore diameter is about 1 to 100 nm, more preferably about 2 to 50 nm. The specific surface area of the porous glass is usually about 4 to 3400 m ² / g, and preferably 9 to 900 m ² / g.
[0018]
The pore diameter and surface area of the porous glass can be controlled by the heat treatment time and temperature.
[0019]
The shape of the porous glass is not particularly limited, and may be any shape according to the purpose of use. For example, porous glass having various shapes such as a flat plate shape and a tubular shape can be used.
[0020]
Method for producing fluorescent glass In the present invention, a chemical vapor transport method is employed as a method for supporting a metal oxide containing a rare earth oxide in the pores of a porous glass. Here, the chemical vapor transport method is a method similar to the commonly used chemical vapor transport method, so-called CVD, and the raw material gas is mixed with the carrier gas and the reaction gas in the pores of the heated porous glass. In this method, an oxide, which is a product of a chemical reaction, is deposited in the pores and supported. As the reaction apparatus, an apparatus as shown in FIG. 1 is used.
[0021]
As a raw material, a β-diketonate complex such as a dipivaloylmethanato (DPM) complex of a rare earth element can be used. The complex is easy to handle because it is in the form of a powder at room temperature, and since the melting point is in a relatively narrow temperature range of 175 to 225 ° C., a gas phase can be simultaneously formed with a composition ratio of a plurality of rare earths mixed first. I can do it. As a result, it is possible to support the rare earth oxide with a desired composition not only in the flat porous glass but also in the porous glass having a complicated shape.
[0022]
As rare earth elements, scandium (Sc), yttrium (Y), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), Examples thereof include gadolinium (Gd), terbium (Tr), dysprosium (Dy), erbium (Er), holmium (Ho), thulium (Tm), ytterbium (Yb), and lutetium (Lu). In the present invention, these β-diketonate complexes of rare earth elements can be used singly or in combination of two or more. Using these rare earth element-containing complexes, the rare earth complex is introduced into the pores of the porous glass by chemical vapor transport (CVD) method, and the rare earth oxide is supported to effectively irradiate the irradiated ultraviolet light. The fluorescent glass having excellent fluorescence and transparency can be obtained.
[0023]
Among the rare earth elements described above, particularly when a β-diketonate complex of at least one element selected from cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium and ytterbium is used. Gives a fluorescent glass having good fluorescence.
[0024]
Further, in addition to the β-diketonate complex of the rare earth elements described above, divalent metals such as alkali metals such as Na and K, alkaline earth metals such as Sr and Ba, and transition metals such as Ti, Pb, Zr and Cu are used. A β-diketonate complex such as pivaloylmethanato (DPM) complex can also be used as a raw material. When a β-diketonate complex of a metal other than these rare earth elements is used as a raw material, a composite oxide in which a rare earth oxide is dispersed in the oxide of these metals as a base material is a fine particle of the porous glass. In this case, good fluorescence performance can be exhibited. When a β-diketonate complex of a metal other than a rare earth element is used as a raw material, it is preferable that the rare earth element is contained in an amount of about 0.01 to 10 atomic% in all the metal elements.
[0025]
In the method of the present invention, a carrier gas is used to introduce a metal complex used as a raw material into the reaction chamber. The carrier gas can be used without particular limitation as long as it is not reactive. For example, argon gas, nitrogen gas, helium gas, etc. are preferably used.
[0026]
Usually, the metal complex used as a raw material is heated to its melting temperature or higher. Thereby, the vaporized metal complex is introduced into the reaction chamber along with the carrier gas.
[0027]
Furthermore, in order to form the target oxide by oxidation reaction with oxygen or decomposition by heating, oxygen-containing gas such as oxygen or air is supplied as necessary.
[0028]
The introduction amount of the raw material complex is determined based on the vapor pressure of the raw material complex and the like, and the introduction amount thereof can be appropriately adjusted by the flow rate of the carrier gas.
[0029]
The distance from the nozzle tube for introducing the raw material and the like into the reaction chamber and the tip of the nozzle to the porous glass is adjusted to about 1 to 30 mm, for example.
[0030]
The temperature of the porous glass is controlled at room temperature to about 800 ° C, preferably about 300 to 600 ° C, more preferably about 400 to 550 ° C. The reaction time varies depending on the amount of the rare earth oxide to be introduced and the like, but is usually about 10 minutes to 100 hours, preferably about 0.5 to 10 hours.
[0031]
In order to efficiently carry a metal oxide containing a rare earth oxide in the pores of the porous glass, one side of the porous glass is in a reduced pressure state, and the raw material accompanying the carrier gas from the other side Introduce a complex (or oxygen or air as the case may be), introduce a raw material into the pores penetrating the porous glass, and deposit an oxide on the inner surface of the pores due to the difference in pressure on both sides Is preferred. The reduced pressure can be adjusted by a rotary pump or the like, and the degree of vacuum can be controlled by a pressure controller. Although the range of pressure reduction is not particularly limited, it may be usually about 0.1 Pa to a pressure lower than atmospheric pressure.
[0032]
Alternatively, after one surface side of the porous glass is in a reduced pressure state and the rare earth oxide is supported by the CVD method, the porous glass is turned over and again the rare earth oxide is supported from the opposite surface side by the same method. good.
[0033]
Fluorescent glass By the above method, a fluorescent glass in which a metal oxide containing a rare earth oxide is supported in the pores of the porous glass is obtained. According to the above-described method, the metal oxide containing rare earth oxide is usually carried as nanometer-order ultrafine particles in the pores of the porous glass. The introduction amount of the rare earth oxide is not particularly limited, and the introduction amount may be appropriately determined according to the required light emission intensity. The upper limit of the amount of oxide to be introduced is usually determined by the pore diameter of the porous glass to be used, but in the method of the present invention, the oxide can be introduced up to the upper limit.
[0034]
When the temperature of the porous glass is low, the rare earth oxide to be formed has a low degree of crystallization and is close to an amorphous state, but crystallization proceeds when the temperature of the porous glass is about 500 ° C. or higher. In addition, the light emission is stronger.
[0035]
The fluorescent glass of the present invention is a highly useful fluorescent glass that is hardly deteriorated in transparency by introducing a metal oxide containing a rare earth oxide and has excellent fluorescence. is there.
[0036]
Such fluorescent glass is a material that can convert ultraviolet light into visible light that can be visually observed with high efficiency. For example, fluorescent lamps for fluorescent lamps, fluorescent fibers, LCD backlights and display devices, EL and FED It can be effectively used for various applications such as flat display materials.
[0037]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, the fluorescent glass which has the outstanding light emission performance can be obtained, without changing the transparency of the porous glass used as a base material largely. Moreover, it can be set as the fluorescent glass which has sufficient durability and intensity | strength by selecting suitably the porous glass used as a base material.
[0038]
Furthermore, by using a rare earth β-diketonate complex as a raw material and adopting a chemical vapor transport method, a rare earth oxide having an arbitrary composition can be easily produced, and a fluorescent glass having a light emitting performance according to the purpose can be obtained. It can be easily manufactured. In addition, it is possible to support rare earth oxides with a desired composition not only on a flat substrate but also on a porous glass having a complicated shape, and various shapes of fluorescent glass that can be used for various purposes can be easily obtained. Obtainable.
[0039]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples.
[0040]
Example 1
As a raw material complex, tris (dipivaloylmethanato) yttrium (Y (DPM) ₃ ) is used as a parent crystal source, and tris (dipivaloylmethanato) europium (Eu (DPM) ₃ ) is used as an activator source. Using. In each case, a rare earth DPM complex with a purity of 99% or more manufactured by Showa Denko Co., Ltd. was used. Using these raw materials, fine particles of Y ₂ O ₃ : Eu ³⁺ were supported in the pores of the porous glass substrate by the following method.
[0041]
As the porous glass, silica-based porous glass made mainly of Akagawa hard glass having pores with a pore diameter of 50 nm was used.
[0042]
FIG. 1 shows a schematic configuration of the rare earth phosphor supporting device used. A predetermined amount of the above-mentioned rare earth DPM complex was put in a Pyrex glass boat and vaporized by heating to 205 ° C. in an electric furnace. The rare earth complex was positioned on the upstream side (left side across the porous glass) of the apparatus, and the downstream side (also right side) was depressurized with a pump to introduce the reaction gas into the pores of the substrate. The reaction was carried out for 10 minutes.
[0043]
The thus obtained rare earth oxide-supported porous glass was subjected to each measurement of UV-VIS spectrum, fluorescence spectrum, XRD and composition analysis.
[0044]
The obtained porous glass had translucency almost the same as that before the reaction. As a result of the UV-VIS transmission spectrum, there was no significant change before and after the treatment, and absorption in the visible range was not observed.
[0045]
In fluorescence spectrum, ⁵ D ₀ - only peak red emission attributed to ⁷ F ₂ was observed.
[0046]
On the other hand, no crystal peak attributed to Y ₂ O ₃ was observed in XRD. From this, it was speculated that Y ₂ O ₃ : Eu ³⁺ introduced into the pores is highly likely to be amorphous.
[0047]
Furthermore, in order to compare the emission intensities, Y ₂ O ₃ : Eu ³⁺ with various activation amounts of Eu ³⁺ ions was synthesized, and the emission intensities were relatively compared. The result is shown in FIG. Y ₂ O _3: porous glass carrying Eu ³⁺ even if a small amount of introduced Eu ³⁺ ions into equivalent Eu ³⁺ ion introduction amount powdered Y ₂ O _3: stronger than Eu ³⁺ It turns out that it emits light.
[0048]
Example 2
A rare earth oxide-supported porous glass was produced in the same manner as in Example 1 except that the temperature of the porous glass was heated to 500 ° C.
[0049]
In the obtained porous glass, crystallization of Y ₂ O ₃ : Eu ³⁺ introduced into the pores has progressed compared to Example 1, and is higher than that of the glass of Example 1. It had a luminescence intensity.
[Brief description of the drawings]
FIG. 1 is a drawing showing a schematic configuration of a rare earth phosphor supporting device used in Example 1. FIG.
FIG. 2 is a graph comparing relative emission intensities of Y ₂ O ₃ : Eu ³⁺ with various activation amounts of Eu ³⁺ ions obtained in Example 1.

Claims (3)

Using a β-diketonate complex of a rare earth element as a raw material, introducing the complex into the pores of porous glass by a chemical vapor transport method, and depositing a rare earth oxide in the pores, For producing fluorescent glass in which a metal oxide containing a rare earth oxide is supported in the pores of a porous glass . The method for producing a fluorescent glass according to claim 1 , wherein a β-diketonate complex of at least one metal selected from alkali metals, alkaline earth metals and transition metals is further used as a raw material. The method for producing a fluorescent glass according to claim 1 or 2 , wherein one side of the porous glass is in a reduced pressure state, and a raw material gas accompanying the carrier gas is introduced into the pores from the other side.

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