KR820001592B1 - Red fluorescent compositions - Google Patents

Abstract

A red-emitting low-energy electron beam-excitable luminescent compds. are obtained by mixing a metallic oxide (2.5μ-14μ) with phosphor selected from LnO2S:Eu; Ln2O3:Eu, LnVO4:Eu; LnBO3:Eu; LnPO4:Eu (Ln = Y, Gd, Eu, or their combinations; 0.65 <=X<=0.9); [(Zn1-x(dx)S:Ag , [Zn3(PO4)2:Mn , and [Cd2B2O5:Mn in a 1:99-1:4 ratio.

Description

Red light emitting composition

1 and 2 are schematic configuration diagrams of typical examples of fluorescent display tubes.

1 is a bipolar tube.

2 is a triode.

11 anode plate 12 fluorescent film 13 ceramic substrate 14 cathode 15 lattice electrode

16: container 17: inside the display tube held in high vacuum

3 is a graph showing the relationship between the IN ₂ O ₃ content (% by weight) and the emission luminance of the composition in a light emitting composition in which IN ₂ O ₃ and Y ₂ O ₂ S: Eu phosphors are mixed.

4 is a graph showing the relationship between the median value of the case where the standard deviation value is constant and the maximum brightness of the composition in the light emitting composition in which IN ₂ O ₃ and Y ₂ O ₂ S: Eu phosphor are mixed.

The present invention relates to a light emitting composition that emits red light. More specifically, the present invention relates to a light emitting composition obtained by mixing an appropriate amount of one or two or more kinds of conductive metal sulfides having a specific particle size distribution with one or two or more specific red light emitting phosphors.

As is well known, an accelerating electron beam excitation fluorescent display tube (hereinafter abbreviated as "fluorescent display tube") includes a positive electrode plate having a fluorescent film on one side and a negative electrode facing the electric fluorescent film in a container having a vacuum inside thereof. It has an enclosed intrinsic structure, excites a fluorescent film on the anode plate with low-speed electron beams emitted from the cathode, and emits light.

1 and 2 are schematic configuration diagrams of a typical example of a fluorescent display tube, and FIG. 1 shows a bipolar tube and FIG. 2 shows a triode.

As shown in FIGS. 1 and 2, the fluorescent film 12 is provided on one surface of the anode plate 11 made of an aluminum plate or the like.

The positive electrode plate 11 is supported by a ceramic substrate 13. There is a cathode 14 facing the electroluminescent film 12 provided on one side of the anode plate 11, and the fluorescent film 12 is excited and emits light by the low-speed electron beam emitted from the cathode 14. In particular, in the triode of FIG. 2, there is a grid electrode 15 for controlling or diffusing the low-speed electron beam emitted from the cathode 14 at a distance between the cathode 14 and the fluorescent film 12. In the fluorescent display tubes shown in FIGS. 1 and 2, one cathode 14 is used, but in the case where the fluorescent film 12 has a large area, two or more cathodes may be made, and the number thereof is not particularly limited. . An electric anode plate 11 having a fluorescent film 12 on one side, a ceramic substrate 13 and a cathode 14 (FIG. 1), or an anode plate 11 having a fluorescent film 12 on one side, a ceramic substrate ( 13), the cathode 14 and the lattice electrode 15 (FIG. 2) are enclosed in a transparent container 16 such as glass, and the inside 17 is held at a high vacuum of 10 ^-6 -10 ^-9 Torr. do.

Conventional light emitting compositions exhibiting high luminance red bladder with low-speed electron beam excitation include indium oxide (In ₂ O ₃ ), europium-active yttrium phosphor (Y ₂ O ₂ S: Eu) and europium-activated yttrium vanadate Luminescent composition (Specific Office Nos. 52-23916), zinc oxide (ZnO), and Y ₂ O ₂ S: Eu phosphor mixed with at least one of the phosphors (YVO ₄ : Eu) in a weight ratio of 1: 9 to 9: 1 A light emitting composition (Japanese Patent Application No. 51-145479) obtained by mixing at least one of a Y ₂ O ₃ : Eu phosphor and a YVO ₄ : Eu phosphor in a weight ratio of 1: 9 to 9: 1 is known.

These luminescent compositions exhibit high luminance red light emission under low-speed electron beam excitation of 1 KV or less, particularly 100 V or less, but in terms of practicality, the light emission luminance is further desired.

It is an object of the present invention to provide a red light-emitting composition having improved luminous luminance under an acceleration voltage of 1 KV or less, particularly 100 V or less, at a low speed electron beam excitation.

x

0.9이다. 이하 똑같다], 망간 활성인산아연 형광체 [(Zn₃(PO₄)₂:Mn]및 망간 활성붕산카드뮴 형광체(Cd₂B₂o₅)에 대하여 상기와 똑같은 효과를 얻을 수 있다는 것을 알아내고 본 발명을 완성시키기에 이르렀다. 본 발명인 발광조성물은 중앙치가 2.5μ내지 14μ,표준편차값(10go)가 0.7이하인 입자경분포가 있는 도전성 금속산화물 및 도전성 금속 황화물의 1종 또는 2종 이상의 도전성 물질과 In₂O₂S : Eu형광체에 함유되는 형광체, Ln₂O₃: Eu형광체에 함유되는 형광체, LnVO₄: Eu형광체에 함유되는 형광체, LnBO₃: Eu형광체에 함유되는 형광체, LnPO₄: Eu형광체에 함유되는 형광체, (Zn₁-x, Cdx)S : Ag형광체, Zn₃(PO₄)₂: Mn 형광체 및 Cd₂B₂O₅: Mn 형광체의 1종 또는 2종 이상의 적색 발광 형광체를 1 :99 내지 1:4의 중량비로 혼합한 것이 특징이다.The present inventors have made various studies to improve the light emission luminance of the above-mentioned red light-emitting composition. As a result, in the case of using an appropriate amount of a particular particle size of In ₂ O ₃ or ZnO with a distribution has to find out that it is possible to obtain a light emitting composition improved the luminescence brightness these effects again, as well as In ₂ O _3, ZnO oxide in place of those Conductive metal oxides such as tin (SnO ₂ ), titanium oxide (TiO ₂ ), tungsten oxide (WO ₃ ), niobium oxide (Nb ₂ O ₅ ), or conductive materials such as cadmium sulfide (CdS) and copper sulfide (Cu ₂ S) Also occurs when a metal sulfide is used, and the red luminescent phosphor which is the other component of the composition is not only Y ₂ O ₂ S: Eu phosphor, Y ₂ O ₃ S: Eu phosphor and YVO ₄ : Eu phosphor, Euro product active earth earth sulfide phosphor represented by Ln ₂ O ₂ S: Eu, Euro product active earth earth oxide phosphor represented by Ln ₂ O ₃ : Eu, and general formula represented by LnVO ₄ : Eu Euro product active earth vanitate phosphor, general formula LnBO ₃ : En Shiha is a euro product active rare earth borate phosphor, and a euro product active earth phosphate phosphor in which the general formula is represented by LnPO ₄ : Eu (wherein Ln is one or two or more of Y, Gd, Lu, and La in each general formula). Same as below), silver zinc sulfide cadmium phosphor [(Zn _1- x, Cdx) S: Ag, where x is 0.65

x

0.9. The same applies to the following], manganese-activated zinc phosphate phosphor [(Zn ₃ (PO ₄ ) ₂ : Mn] and manganese-activated cadmium borate phosphor (Cd ₂ B ₂ o ₅ ), and the present invention was found to have the same effect as above. The light emitting composition of the present invention has one or two or more conductive materials of conductive metal oxides and conductive metal sulfides having a particle size distribution having a median value of 2.5 µ to 14 µ and a standard deviation value of 10go of 0.7 or less, and In _2. O ₂ S: phosphor contained in Eu phosphor, Ln ₂ O ₃ : phosphor contained in Eu phosphor, LnVO ₄ : phosphor contained in Eu phosphor, LnBO ₃ : phosphor contained in Eu phosphor, LnPO ₄ : contained in Eu phosphor One or two or more red light emitting phosphors of phosphors, (Zn _1- x, Cdx) S: Ag phosphors, Zn ₃ (PO ₄ ) ₂ : Mn phosphors, and Cd ₂ B ₂ O ₅ : Mn phosphors may be 1:99. It is characterized by mixing in a weight ratio of 1: 4.

In the fluorescent display tube using the light emitting composition of the present invention, the fluorescent film has a structure in which a cathode plate having a fluorescent film on one side and a cathode facing the electroluminescent film are enclosed in a vacuum container therein. One or two or more conductive materials such as conductive metal oxides and conductive metal sulfides having a particle size fraction having a median value of 2.5 μm to 14 μm logo or less, and a phosphor contained in an Ln ₂ O ₂ S: Eu phosphor, and Ln ₂ O ₃ : phosphor contained in Eu phosphor, LnVO ₄ : phosphor contained in Eu phosphor, LnBO ₃ : phosphor contained in Eu phosphor, LnPO ₄ : phosphor contained in Eu phosphor, (Zn _1- x, Cdx) S : Ag phosphor, Zn ₃ (PO ₄ ) ₂ : Mn phosphor and Cd ₂ B ₂ O ₅ : Mn phosphor of one kind or two or more kinds of red light emitting phosphor mixed in a weight ratio of 1:99 to 1: 4 as a light emitting composition It is characteristic that it was made.

Examples of the conductive metal oxide and the conductive emulsion used in the conductive material as constituents of the light emitting composition of the present invention include In ₂ O ₃ , ZnO, SnO ₂ , TiO ₂ , WO, Nb ₂ O ₅ , and CdS, Cu ₂ S, and the like. have. In particular, it is preferable to use a conductive metal oxide in terms of the luminance of the produced composition, among which In ₂ O ₃ , SnO ₂ and ZnO are more preferable.

These electroconductive metal oxides and electroconductive metal stupa oxide are used for the particle size distribution whose median value is 2.5 micrometers-14 micrometers, and a standard deviation value is 0.7 or less. If the median value is outside the above range and the particle size distribution having a standard deviation value of greater than 0.7 is used, the emission luminance of the composition to be produced is not used. The better median range depends on the type of red light-emitting phosphor to be mixed with the conductive material, but is generally in the range of 3 μm to 10 μm. In addition, the smaller the standard value is, the better the smaller the standard deviation is, and in general, 0.5 or less is better.

The conductive metal oxide and conductive metal sulfide having the particle size distribution as described above may classify the fired product formed by firing a general reagent or a general reagent in an air, a heavy-molecular atmosphere, or a weakly reducing atmosphere with a sieve, or a bowl mill or a roll mill. It can be obtained by pulverizing and classifying with a sieve or the like.

The conductive metal oxide may be obtained by firing a compound which can easily be converted into a metal oxide at high temperature such as carbonate, sulfate, oxalate, and hydroxide in air to obtain a metal oxide, and classifying it. The use of the fired product is because the fired product has better safety of temperature characteristics with respect to the unfired raw meal, and therefore, the composition having better light emission stability can be produced than when the fired product is used. In general, when the conductive sulfide is fired, its conductivity is remarkably improved, and therefore, a fired product is preferably used.

Meanwhile, Ln ₂ O ₂ S: Eu phosphor, Ln ₂ O ₃ : Eu phosphor, LnVO ₄ : Eu phosphor, LnBO ₃ : Eu phosphor, Zn _1- x, Cdx) S: Ag phosphor, Zn ₃ (PO ₄ ) ₂ : Mn phosphor and Cd ₂ B ₂ O ₅ : Mn phosphor were prepared by a conventionally known production method. These phosphors generally have a particle size distribution with a median of 1 µm to 20 µm and a standard deviation of 0.7 or less. Especially in this invention, it is preferable that median is 3 micrometers-10 micrometers.

Among these phosphors, Y ₂ O ₂ S: Eu phosphors (included in Ln ₂ O ₂ S: Eu phosphors), YVO ₄ : Eu phosphors (in LnVO ₄ : Eu phosphors), It is preferable to use YBO ₃ : Eu phosphors (included in LnBO ₃ : Eu phosphors), and Cd ₂ B ₂ O ₅ : Mn phosphors, more preferably Y ₂ O ₂ S: Eu phosphors and YBO ₃ : Eu Phosphor.

For Ln ₂ O ₂ S: Eu phosphor, Ln ₂ O ₃ : Eu phosphor, LnVO ₄ : Eu phosphor, LnBO ₃ : Eu phosphor, and LnPO ₄ : Eu phosphor may be used co-active with Tb or the like. (Zn _1- x, Cdx) S: An Ag phosphor may be co-activated with Cl or the like.

The light emitting composition of the present invention can be prepared by sufficiently mixing the above-described conductive material and red light-emitting phosphor with a mortar, bowl mill, mixer, or the like. Both are mixed in a weight ratio such that the value of the conductive material / red light emitting phosphor is 1/99 to 1/4.

When the value of the conductive material / red light-emitting phosphor is less than 1/99 (when the conductive material is less than 1% by weight of the total amount of the composition), the charge-up prevention effect by the conductive material does not sound and therefore the composition is characterized by its characteristics. It becomes closer to this red light-emitting phosphor and does not emit light under low-speed electron beam excitation.

On the other hand, when the value of the conductive material / red light emitting phosphor is greater than 1/4 (when the conductive material is more than 20% by weight of the total amount of the composition), the resulting composition is very weak in luminescence. This may be thought to be due to the fact that the charge-up prevention effect is sufficient but light emission from the phosphor is blocked by the conductive material. In terms of luminescence luminance, the more preferable value of the conductive material / red light emitting phosphor is generally 3.197 (1.5 wt% of the conductive material in the total amount of the composition) to 1/9 (10 wt% of the conductive material in the total amount of the composition).

The preferred combination of the conductive material and the red light emitting phosphor in the light emitting composition of the present invention is In ₂ O ₃ and Y ₂ O ₂ S: Eu phosphor, SnO ₂ and Y ₂ O ₂ S: Eu phosphor and In ₂ O ₃ and YBO ₃ : Eu phosphor. The composition of these combinations is particularly high in luminance.

3 is a graph showing the relationship between the In ₂ O ₃ content (wt%) and the luminance of the composition in the light emitting composition containing In ₂ O ₃ and Y ₂ O ₂ S: Eu phosphors. c is the standard deviation value of 0.4, respectively, but the median value of In ₂ O ₃ with 4.5μ, 8μ and 20μ respectively.

In Fig. 3, the emission luminance (vertical axis) is expressed as a relative value where the maximum emission luminance of the curve c is 100%.

As is clear claim 3 degrees, In ₂ O ₃ content, the middle value was necessary to achieve quality becomes smaller when the maximum brightness of light emitted by the In ₂ O ₃ is smaller than. That is, when In ₂ O ₃ having a small median value is used, light emission with high luminance can be obtained with a smaller In ₂ O ₃ content than when In ₂ O ₃ having a larger median value is used.

Also, as is clear from FIG. 3, when the maximum emission luminance at each median is compared, the maximum emission luminance tends to improve as the median value of In ₂ O ₃ decreases, but as shown in FIG. The luminance tends to decrease inversely as the median becomes smaller. 4 shows the median value of In ₂ O ₃ and the maximum value of the composition when a standard deviation and a constant (a = 0.4) are obtained in a light emitting composition in which In ₂ O ₃ and Y ₂ O ₂ S: Eu phosphors are mixed as It is a graph which shows the relationship with light emission luminance. In FIG. 4, maximum luminescence brightness (vertical axis) was expressed as a relative value of 100% of the maximum luminescence brightness of the composition using In ₂ O ₃ having a median value of 20 µ.

As is apparent from FIG. 4, the maximum emission luminance tends to start to decrease as the median becomes smaller until the median is about 4.5 mu.

Common reagents of In ₂ O ₃ is typically 20μ to about 30μ, but with a median value of the common reagents of considering the basis of brightness of light emitted by the light emitting composition using an In ₂ O _3, the middle value was selective to 2.5μ to 14μ of In ₂ O ₃ It can be seen that the light emitting composition with improved luminous luminance can be produced when used as a. In particular, when In ₂ O ₃ having a median value of 3 µm to 10 µm is used, a composition with remarkably improved emission luminance can be produced.

The standard deviation also affects the luminous luminance of the composition. That is, in the median value range of 2.5 mu to 14 mu, the light emission luminance generally tends to decrease as the standard deviation increases. This is because the larger the standard value is, the larger the number of particles containing large and small particles are, the lower the contribution to the luminance is. In this regard, the standard deviation is set to 0.7 or less. More preferably, it is 0.5 or less.

3 and 4 are graphs of light emitting compositions in which In ₂ O ₃ and Y ₂ O ₂ S: Eu phosphors are mixed, but in the case of using other conductive metal oxides or conductive metal sulfides instead of In ₂ O ₃ , or Y _The use of other red light-emitting phosphors instead of ₂ O ₂ S: Eu phosphors also tended to the same as in FIG. 3 and FIG.

In the light emitting composition of the present invention, the conductive metal oxide and the conductive metal sulfide are limited to those having a particle size distribution having a median value of 2.5 μm to 14 μm and a standard deviation of 0.7 or less, and the mixing weight ratio of the conductive material and the red light emitting phosphor is 1:99. It is based on the above-mentioned opinion that what was limited to 1: 4.

The fluorescent display tube using the light emitting composition of the present invention is produced by the method described below.

First, the above-described light emitting composition is applied on a positive electrode plate which is usually supported by a ceramic substrate by the deposition coating method to form a fluorescent film. That is, a positive electrode plate is placed in a suspension in which the composition is dispersed in water, and the composition is applied by needle-coating on one side of the positive electrode plate with the weight of the composition, and then water is removed to dry the chips. In order to improve the adhesion between the resulting fluorescent film and the positive electrode plate, a small amount (0.01-0.1%) of water glass may be added to the suspension. In addition, the coating density is suitably 5 mg / cm 2 -30 mg / cm 2.

In addition, although the above-mentioned sedimentation coating method is generally used and widely used, the method of preparing a fluorescent film in a fluorescent display tube using the light emitting composition of the present invention is not limited to this sedimentation coating method.

Next, a cathode coated with a linear heater with oxides such as BaO, SrO, CaO, and the like is opposed to a fluorescent film on the anode plate, and is disposed at intervals of about 1 mm-5 mm, and the pair of electrodes is placed in a glass or the like. It is installed in a transparent container and then evacuated. After the inside of the container has reached a vacuum degree of at least 10 ^-5 Torr or more, the exhaust is stopped and sealed. After encapsulation, the getter is blown to further increase the degree of vacuum in the container.

In this way, a fluorescent display tube can be made.

In addition, since the fluorescent film on the anode plate is flat and the cathode is linear, it is preferable to provide a mesh-like lattice electrode as a diffusion electrode in the middle between the cathode and the fluorescent film in order to diffuse the low-speed electron beam emitted from the cathode. .

In this case, it is possible to obtain a good result in that the mesh is as small as possible so that the amount of emitted light of the fluorescent film is small and the low-speed electron beams diffuse well. Specifically, the diameter of the mesh may be 500 microns or less, and the aperture ratio (the area of the hole for transmitting the low-speed electron beam to the entire area of the grid electrode) may be 50% or more.

The positive electrode plate can be displayed in arbitrary letters and figures by dividing the electrode plate into the shapes of letters and figures that require the electrode shape, and allowing each electrode to selectively apply the required voltage.

The anode plate is divided into dots or lines, and a fluorescent film of a light emitting composition obtained by mixing WO ₃ and ZnS: Ag is formed on a part of the electrodes, and a low-speed electron beam excitation color different from that of the electrical composition is formed on the other electrode. By forming a fluorescent film made of a molten phosphor, a fluorescent display tube capable of multicolor display can be made.

As mentioned above, the present invention provides a red light-emitting composition having improved luminous luminance under low-speed electron beam excitation of 1 KV or less, particularly 100 V or less, and its industrial value is large.

Next, the present invention will be described by way of examples.

Example 1

The In ₂ O ₃ reagent was pulverized and then classified into a sieve to obtain In ₂ O ₃ having a particle size distribution with a median of 8, and a standard deviation of 0.4.

7 g of In ₂ O ₃ and 93 g of Y ₂ O ₂ S: Eu phosphor having a particle diameter of 7 mu and a standard deviation value of 0.35 having a median normally prepared by a manufacturing method were sufficiently mixed with induction.

100 mg of the resulting composition was added to 100 cc of distilled water and ultrasonically dispersed. A 2 cm x 1 cm aluminum anode plate supported by a ceramic substrate was placed in the dispersion and allowed to stand for 30 minutes, and then clear water was removed and dried to form a fluorescent film.

Next, an anode coated with a tungsten linear heater with an oxide is opposed to a fluorescent film on the anode plate, and is arranged at intervals of about 5 mm, and the pair of electrodes are placed in a hard glass container, followed by evacuating the container and then blowing the getter. The degree of vacuum inside was further increased.

Thus, the fluorescent display tube of the structure shown in FIG. 1 was obtained.

This fluorescent display tube showed red light emission with a light emission luminance of 100 ft-L when the anode plate voltage was 90 V, the anode voltage was 1.2 V, and the anode plate current density was 2 mA / cm 2.

Example 2

The In ₂ O ₃ reagent was pulverized, and then classified by a sieve to give In ₂ O ₃ having a particle size distribution having a median of 4.5 mu and a standard deviation of 0.4. ₃ g of this In ₂ O ₃ and 97 g of the Y ₂ O ₂ S: Eu phosphor as in Example 1 are sufficiently mixed with induction.

A fluorescent display tube was produced in the same manner as in Example 1 with the composition produced here. In the fluorescent display tube, when the anode plate voltage is 90 V, the cathode voltage is 1.2 V, and the anode plate current density is 2 mA / cm 2, red light emission of 117 ft-L is shown.

Example 3

The Sn ₂ O ₃ reagent was ground and then classified, resulting in SnO ₂ with a particle size distribution with a median of 8 microns and a standard deviation of 0.4 microns.

7 g of this SnO ₂ and 93 g of the Y ₂ O ₂ S: Eu phosphor as in Example 1 are sufficiently mixed with each other to induce.

Using the composition produced in the same manner as in Example 1 to prepare a fluorescent display tube. In the fluorescent display tube, when the anode plate voltage is 90 V, the cathode voltage is 1.2 V, and the anode plate current density is 22 mA / cm 2, red light emission of 90 ft-L is emitted.

Claims (1)

One or two or more conductive materials of a conductive metal oxide and a conductive metal sulfide having a particle size distribution having a median value of 2.5 to 14 µ and a standard deviation value of 10go of 0.7 or less, and a general formula represented by Ln ₂ O ₂ S: Eu A phosphor contained in the europium activated rare earth oxysulfide phosphor, a phosphor contained in the europium active rare earth oxide phosphor represented by the general formula Ln ₂ O ₃ : Eu, and a utopium active rare earth vanadate phosphor represented by the general formula LnVO ₄ : Eu. Phosphor contained, phosphor contained in the europium active rare earth borate phosphor represented by the general formula LnBO ₃ : Eu, phosphor contained in the europium active rare earth phosphate phosphor represented by the general formula LnPO ₄ : Eu, and silver activated zinc cadmium sulfide phosphor [( Zn _1- x, Cdx) S: Ag], one or two of manganese-activated zinc phosphate phosphors (Zn ₃ (PO ₄ ) ₂ : Mn) and manganese-activated cadmium borate phosphors (Cd ₂ B ₂ O ₅ : Mn) More than ever A light emitting composition comprising a color-emitting phosphor mixed at a weight ratio of 1:99 to 1: 4 (wherein Ln is one or two or more of Y, Gd, Lu, and La, and X is 0.65

X

Is a number satisfying a condition of 0.9)

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