JPS62174290A - Production of luminescent composition - Google Patents

Abstract

PURPOSE:To provide a luminescent compsn. which exhibits a highly effective luminescence under condition of excitation by means of low-velocity electron beams, by mixing particles of a fluorescent substance with a sol xomprising In2O3 as its major component, followed by drying, so as to allow a conductive metal oxide mainly comprised of In2O3 to adhere to the surface of fluorescent substance particles. CONSTITUTION:A sol compsn. comprising indium oxide as its major component (e.g., indium oxide sol or indium-tin sol compsn.) is manufacture by a method comprising contacting a solution contg. a solution cong. an inorg. indium salt such as InCl3 as its major component with an ion exchange resin, or other methods. this sol compsn. is mixed with particles of a fluorescent substance (e.g., ZnS:Zn). The mixture is dehydrated and dried so as to allow particles or a film of a conductive metal oxide comprising indium oxide as its major component to adhere to the surface of fluorescent substance particles. Thus, the desired luminescent compsn. is obtd. The luminescent compsn. obtd. exhibits a highly effective luminescence under the condition of excitation by low-velocity electron beams such as those of 100V or less.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention is mainly applicable to applications where the accelerating voltage is less than 1kv, especially 100v.
The present invention relates to a method for producing a light-emitting composition that emits light with high efficiency under the following excitation with a slow electron beam.

(Prior art) A zinc-activated zinc oxide phosphor (Z
nO:Zn), a europium-activated tin oxide phosphor <sn02:Eu), which emits orange-red light, are known. It has been used as a phosphor for display tubes for a long time. After that, b, which is a phosphor with extremely low luminous efficiency under slow electron beam excitation, is added to a predetermined amount of lr+20. .

49 Electron gold EM compounds such as Zn 0, 3n 02 “+”
) CdS.

(In this specification, a luminescent composition is obtained by mixing a conductive metal oxide such as Nυ2S with a conductive substance.) Alternatively, compositions obtained by adhering or coating the surface of phosphor particles with a conductive substance are collectively referred to as "luminescent compositions") exhibit highly efficient luminescence by excitation with a slow electron beam. It has been discovered that such luminescent compositions can produce a desired luminescent color quickly by selecting the phosphor that is one of the constituent components, and have recently been used together with the conventionally used zno: zn. It has come into widespread practical use for multi-color fluorescent display tubes.

(Problems to be Solved by the Invention) By the way, since the process of conventional luminescent compositions is relatively simple, it is necessary to mechanically mix a predetermined amount of phosphor and conductive substance in a mortar, ball mill, etc. The most commonly used manufacturing method is However, the conventional luminescent composition obtained in this way is
o: Since the luminous efficiency under slow electron beam excitation is lower than that of zn, various attempts have been made to improve it. Special Public Service No. 59-33153
No., Special Publication No. 59-33155, Special Publication No. 60-4614
9 etc.), there is a desire for even higher efficiency of luminescent compositions as fluorescent display tubes become more colored and the field of use thereof expands.

The present invention has been made in view of the above-mentioned needs, and is capable of emitting light with higher efficiency than light-emitting compositions obtained by conventional manufacturing methods under slow electron beam excitation at accelerating voltages of ikV or less, particularly 100V or less. An object of the present invention is to provide a method for producing a light-emitting composition.

(Means for Solving the Problems) In order to achieve the above object, the present inventors have determined the type and properties of the conductive substance that is one of the components of the luminescent composition, and the method of mixing the phosphor and the conductive substance. As a result of intensive research on the above, it was discovered that by mixing a phosphor and a sol composition containing indium oxide as the main component and drying this, a luminescent composition with higher efficiency than conventional ones could be obtained. , we have completed the present invention.

The method for producing a luminescent composition of the present invention includes a step of mixing phosphor particles and a sol composition containing indium oxide as a main component;
It is characterized by comprising a step of dehydrating the mixture and a step of drying it after that, and attaching particles or a film of a conductive metal oxide containing indium oxide as a main component to the surface of the phosphor particles. .

(Example) Next, the manufacturing method of the present invention will be explained in more detail.

First, a phosphor exhibiting a desired luminescent color and a sol composition such as an indium oxide sol, an indium tin sol composition, or an indium antimony sol composition (hereinafter collectively referred to as "indium oxide as the main component and J A predetermined amount of the sol composition (hereinafter referred to as "sol composition") is mixed thoroughly using a stirrer.

The sol composition containing indium oxide as a main component used in the production method of the present invention may be produced by a known method such as that disclosed in JP-A-59-219810. That is, InCl3, In (
Inorganic indium salt such as NO3)3 or 3n C14
, A method of preparing an aqueous solution of an inorganic indium salt containing Sb C1s, etc., a mineral acid solution, a methanol solution, an ethanol solution, etc., and bringing this into contact with an ion exchange resin, a liquid phase of the inorganic indium salt and an alkaline substance. A gel composition containing -H indium oxide as a main component is obtained by a liquid phase neutralization reaction between the inorganic indium salt and an alkaline substance, and then this gel composition is hydrothermally treated to form a sol. It can be manufactured by a method such as

Note that, among these, a sol composition containing indium oxide as a main component obtained by the method of bringing an inorganic indium salt solution into contact with an ion exchange resin is preferable because it can further improve the luminous efficiency of the luminescent composition obtained. In this case, the solvent for the inorganic indium salt solution is usually water, mineral acid, acetone, or methanol, depending on the solubility of the inorganic indium salt used, the dispersibility of the sol, etc. A single solution or a mixture of organic solvents such as ethanol, ethylene glycol, and methyl sululose can be used. In order to further improve the luminous efficiency of the obtained luminescent composition, after adjusting the pH value of the inorganic indium salt solution to a range of approximately 0.1 to 3 by adding mineral acid, Add an anion exchange resin in an amount having an ion exchange group of approximately 0.5 equivalent or more of the total anion i1 in the solution, and when the pH value of the solution reaches J3 approximately 4 to 10, ion exchange begins. It is preferable to use a sol composition containing indium oxide as a main component obtained by separating the resin.

On the other hand, the phosphor used in the manufacturing method of the present invention is not particularly limited, and any phosphor can be used depending on the luminescent properties of the phosphor, but ZnS:Zn
, ZnS:Au, ZnS:Cu, ZnS:Ao, ZnS
:Ao, A9J, ZnS: Au, A9J, ZnS:
Cu, A! 2. , Zn (S.

Se): Ag, Zn (S, Se): Ag, A9
．． .

(Zn, Cd)S: Cu, (Zn, Cd)S
:Cu, A9J, (Zn, Cd)S:A9. (Zn,
Cd) S: A(1, △12.. Zn (S, 3e
) :Cu.

Zn (S, Se): Cu, AR, (Zn
, Cd) S: Au, A 9. When a sulfide-based phosphor or a sulfide-based phosphor of '8 is used, a particularly highly efficient light-emitting composition can be obtained.

In J3 of the production method of the present invention, the optimum addition ω of the sol composition containing indium oxide as the main component to be mixed varies slightly depending on the type of phosphor used, but the conductive metal oxide containing indium oxide as the main component If the content of the product is the same, it is higher than that produced by the conventional method'C! In order to obtain a luminescent composition of 1'li degree, the conductive metal oxide product containing indium oxide as a main component in the sol composition containing indium as a main component is added to approximately Preferably, the amount corresponds to 0.5 to 30%.

Next, the mixture of the phosphor and the sol composition containing indium oxide as a main component obtained as described above is dehydrated,
By drying at a temperature of 50°C to 200°C, it is possible to obtain a luminescent composition consisting of phosphor particles on the surface of which particles or films of conductive gold titanium oxide, the main component of which is indium oxide, are attached or coated. I can do it.

Figure 1 shows (Zn, 44. Cd, 36) S: A
Q. Regarding a luminescent composition consisting of a CI phosphor and [n203, what is the relationship between the content of InzO3 in the luminescent composition and the relative luminous efficiency when the luminescent composition is excited with a slow electron beam to emit light? The curves shown as solid lines and the curves shown as dashed lines correspond to the luminescent composition produced by the production method of the present invention and the conventional method ((lny, H,
Cdo, 36) S: AQ, CI phosphor and I
This invention relates to a luminescent composition prepared by mechanically mixing n2O3. In the figure, the content of 10203 (horizontal axis) indicates the analysis value C of [r+z○3] contained in the obtained luminescent composition in the case of the curve shown by the solid line, and the content of 10203 (horizontal axis) indicates the analysis value C of The immersion Δ of added InzO3 is shown.

As is clear from FIG. 1, according to the present invention (solid line), a luminescent composition with higher efficiency can be obtained with a lower content of InzO3 than in the conventional method (dashed line).

Furthermore, when comparing the respective optimum 1n203-containing ω luminescent compositions, the luminescent efficiency of the luminescent composition produced by the production method of the present invention is significantly higher than that produced by the conventional method.

Figure 2 a J5 and b are J
: tte (ZnO, Ip, Cd,,!4) S : A
g. Electron microscopy of a luminescent composition in which a film consisting of 1n203 and 1n203 particles were attached to the surface of CI phosphor particles, and a conventional luminescent composition prepared by mixing the same phosphor and Ir1z03 particles by a conventional method (q). This figure is an example of the photograph taken by S1.As is clear from FIG. In addition to the phosphor particles 203 attached thereto, it can be seen that the surface of the phosphor particles is covered with a transparent film of 1n203.

Example 7 Indium nitrate [In <NO3): l ・3.
1-120] was dissolved in 400 cc of ethyl alcohol and 20 cc of concentrated nitric acid, and pure water was added to this so that the total ω was 800 cc to prepare an aqueous solution of indium nitrate, and further NaOH was added to dissolve the solution. The pH value was adjusted to 2.0. Next, add volume fl 400c to this solution.
The ion exchange resin (S△-10 manufactured by Nippon Rensui KK) of c was added and sufficiently stirred until the pH firi of the solution reached approximately 7, and then the ion exchange resin was separated. 400 g of <lno, t4. Cd,, aa) S: AQ,
Add CI phosphor, mix thoroughly, dehydrate, and boil at 150 ml.
Dry with humidity at °C (ZnCdo, a6)S
A luminescent composition (1) was obtained in which 5% (actual analysis value) indium oxide was adhered to the surface of A(+, CI phosphor powder 0.6ψ-).

For comparison, (ZnCd)S:Aa, Co,
F9L10・3b 1 Phosphor and indium oxide 95=56 and 80:
Luminescent compositions (■') and (■'') were prepared by mixing the compositions in a ball mill at a car-quality ratio of 20.

The luminescent composition thus obtained (■).

The applied voltage and anode current necessary to obtain the same luminescence brightness when excited with a slow electron beam were measured for (I') and (E), and the relative luminous efficiency of each luminescent composition was determined. 215°100 and 110 respectively
The luminous efficiency of the luminescent composition (I) is higher than that of the luminescent composition (■') J3 with the same 1n203 content as the luminescent composition (I) and the luminescent composition with the optimal 1n203 content produced by the conventional method. (I″).

Example 2 Indium chloride (In Cd3 4Hz O) 42g
was dissolved in 1.69 J of water, and Na01-1 was added to make p
An indium chloride solution with an H value of 2.8 was prepared. To this solution, 800 cc of ion exchange resin (WA-30 manufactured by Nippon Rensui KK) was added, and the solution was thoroughly stirred until the pH value of the solution reached approximately 6.0, and the ion exchange resin was separated. Thus obtained indium oxide medium 4009
ZnS: Au, /l, after adding the phosphor and mixing thoroughly, dehydrated and dried at a temperature of 150 °C, ZnS
S: Au, /l, a luminescent composition in which 5% a% (actual analytical value) of indium oxide is attached to the surface of a phosphor (
I[) was obtained.

For comparison, 7-n3:Au, A9J phosphor and indium oxide were used at 95:5 and 80:20 il+.
Luminescent compositions (■') and (■'') were prepared by mixing the compositions in a ball mill at the ffi ratio.

The luminescent composition thus obtained (■).

(II') When J3 and (II'') were excited with a slow electron beam and the luminous efficiency of each luminescent composition was measured in the same manner as in Example 1, their relative values were 180°100 and 120, respectively. , the luminous efficiency of the luminescent composition (If) was higher than that of the luminescent composition (II) produced by a conventional method.
The 203 content ω was significantly higher than that of the luminescent composition (If') Jj having the same content and the luminescent composition (I'') having the optimum 1n203 content.

Example 3 U 400'J (l no, 4, 4. C
daj & ) S: 2009 Z in place of Ag, Cmen
In the same manner as in Example 1 except that nS:Cu, Ai was used, 10 wt% (
A luminescent composition (III) to which indium oxide of actual analysis value was attached was obtained.

For comparison, luminescent compositions (■') and (1'') were produced by mixing ZnS:Cu, AiQ, phosphor, and indium oxide in a ball mill at weight ratios of 90:10 and 80:20, respectively. .

The luminescent composition thus obtained (■).

When ([1')Jj and (III'') were excited with a slow electron beam and the luminous efficiency of each luminescent composition was measured in the same manner as in Example 1, the relative luminous efficiency of each was 190.
100 and 110, and the luminous efficiency of the luminescent composition (I [
III) and a luminescent composition with the same rnzo3 content (I11'
) J3 and optimal 1n203 containing 10 luminescent compositions (1”)
It was significantly higher.

Example 4 Indium chloride (ln C13・4H20) 25.2 nitride and tin chloride (Sn CI t・3H20) 1
．． Dissolve 8g in hydrochloric acid, and make the entire product 2.4i J: Add pure water to make indium chloride containing tin chloride, and further add Na0l-1 to adjust the pH of the solution.
The value was adjusted to 2.0. Next, add volume ω to this solution.
1000cc of ion exchange resin (5A- manufactured by Nippon Pure Water KK)
10) was added and thoroughly stirred until the pH value of the solution became approximately 8.0, and the IP and the ion exchange resin were separated. After adding 400 g of ZnS:Aa, A-type body into the indium oxide/tin oxide sol obtained in this manner and stirring thoroughly, it was dehydrated and dried at a temperature of 150°C to give ZnS:Δ(1 , AQ, 31f on the surface of the phosphor particles
A luminescent composition to which a mixture of indium oxide and g oxide of 7.5 wt ω% (actual analytical value) including M% tin oxide is attached (
■) was obtained.

For comparison, a luminescent composition (IV ') and (IV'') to 11!
! Built.

The luminescent composition thus obtained (■).

When (IV') J5 and (IV") were excited with a slow electron beam and the luminous efficiency of each luminescent composition was measured in the same manner as in Example 1, the relative luminous efficiency of each was 250.
100 and 150, and the luminous efficiency of the luminescent composition (IV) is higher than that of the luminescent composition (E
V ) with the same content of the indium oxide-tin oxide mixture as compared to the luminescent composition (IV') J3 and the luminescent composition (IV'') containing the optimal indium oxide-tin oxide mixture.

(Effects of the Invention) As described above, the production method of the present invention exhibits significantly more efficient light emission under slow electron beam excitation than conventional light emitting compositions. # In addition to being able to reduce the amount of light emitting composition by 1r7, it is also possible to obtain a light emitting composition that exhibits highly efficient light emission by using a smaller amount of conductive metal oxide additive 77101 than in conventional light emitting compositions.

[Brief explanation of drawings]

FIG. 1 illustrates the relationship between the content of a conductive substance and the luminous efficiency under slow electron beam excitation in a luminescent composition obtained by the production method of the present invention and a luminescent composition obtained by a conventional production method. It is a graph. FIG. 2 illustrates electron microscopic photographs of a luminescent composition obtained by the production method of the present invention and a luminescent composition obtained by a conventional production method. (Method) 114 Indications 1511-1 1986-16070 Class 2, Name of the invention Method for manufacturing a luminescent composition 3, Relationship with the person making the amendment Jif'l Patent Crystal 1 Applicant's address
2-12-7 Shibadaimon, Minato-ku, Tokyo Name: Kasei Opi Henix Co., Ltd. 4, Agent: 5-1 Rokigi, Minato-ku, Tokyo 2-1 11fl March 5, 1961 (Shipping date: Showa 61 year 3
Month 251-]) 6. Number of inventions increased by amendment
None 7, Subject of correction Akira m; ” Insert a line indicating a one-particle structure between “1J” and “1J”.

Claims (1)

[Claims] 1) Mix phosphor particles and a sol composition containing indium oxide as a main component, dehydrate the mixture, and then dry it.
A method for producing a light-emitting composition, characterized in that particles or a film of a conductive metal oxide containing indium oxide as a main component are attached to the surface of the phosphor particles.