JP2000303065A - Phosphor for vacuum ultraviolet ray, phosphor paste composition and luminescent element excited by vacuum ultraviolet ray - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a high-luminance phosphor which hardly undergoes the decrease in emission luminance in the step of forming a phosphor film by coating the surface of phosphor particles with an Sr compound and/or a Ba compound. SOLUTION: The Sr compound and/or the Ba compound is preferably a borate or phosphate, and borate compounds including strontium tetraborate (SrB4O7) and barium tetraborate (BaB4O7) are especially preferable. The compound is applied preferably in such an amount that the total amount of Sr and Ba is 0. 005-5 wt.% of the phosphor, still preferably 0. 03-2 wt.%. The precipitate of the Sr compound and/or the Ba compound is formed in a slurry containing a phosphor suspended therein and is deposited on the surface of the phosphor to coat it. Thus, a phosphor having a high initial luminance is obtained and the decrease in emission luminance in the step of forming a phosphor film can be made small. When an aluminate phosphor, especially a blue-emitting phosphor (which is strongly required to be improved in decrease in luminance), is coated, the decrease in luminance during baking can be made small.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phosphor which emits light when excited by irradiation with vacuum ultraviolet rays used for a plasma display panel (PDP), a rare gas discharge lamp, etc., and a phosphor paste composition containing the phosphor. And a VUV-excited light-emitting device including a phosphor film formed using the phosphor paste composition.

[0002]

2. Description of the Related Art In recent years, a fluorescent substance in a vacuum envelope is sealed by a vacuum ultraviolet ray (VUV) radiated by discharge of a rare gas such as Ar, Xe, or He sealed in a vacuum envelope such as glass. 2. Description of the Related Art Vacuum ultraviolet ray excited light emitting devices that emit light by excitation have been actively developed.

As one example of the vacuum ultraviolet ray excited light emitting device, there is a thin tube lamp used as a reading light source of an image scanner. This is because He-Xe, Ne is contained in a glass tube.
A rare gas such as -Xe is sealed therein.
When a fluorescent film made of a phosphor is formed and, for example, electric energy is applied through electrodes provided at both ends of the thin tube, a rare gas discharge occurs in the thin glass tube, and VUV is radiated. The fluorescent film is excited to emit visible light. As the phosphor for the phosphor film, V
There are a single color of red, blue, and green, which emits light with high efficiency when excited by UV, and a mixture of these three-color phosphors.

Another example of a vacuum ultraviolet ray excited light emitting device is a PDP.
There is. A PDP can be considered as a product in which three-color thin-tube lamps of different colors emitted by VUV are reduced, and a large number of the three-color thin-tube lamps are arranged in a matrix in a fixed arrangement. That is, a vacuum envelope (cell) having a narrow discharge space is arranged in a matrix.
Each cell is provided with a fluorescent film made of an electrode and a phosphor for vacuum ultraviolet rays, and each cell contains He-Xe,
A rare gas such as Ne-Xe is sealed. When electric energy is applied from the electrodes of each of these cells, a rare gas discharge occurs in the cells, and VUV is radiated.
The UV excites the phosphor of the phosphor film inside the cell to emit visible light. By arranging cells having fluorescent films that emit red, blue, and green light in a matrix, an image is displayed by a combination of these light emission, and a full-color image display can be performed.

[0005] The fluorescent film of a vacuum ultraviolet ray excited light emitting element such as a capillary lamp or a PDP is coated with a phosphor paste composition produced by dispersing a phosphor for vacuum ultraviolet light in a binder resin containing an organic solvent, and then dried. After that, a method of baking and forming this is mainly adopted.

That is, since light emission is generally monochromatic in a thin tube lamp, the phosphor film is formed by applying a phosphor paste composition on the inner wall of the thin glass tube, drying and baking the inner surface of the glass tube. Then, a fluorescent film is formed. On the other hand, in the case of a color PDP, it is necessary to form a phosphor screen in which three color phosphor layers are arranged in a fixed pattern.
For this pattern formation, a three-color phosphor paste composition is pattern-coated on a substrate using a method such as screen printing and dried, or a screen printing method in which a photosensitive resin is used on the entire surface of the substrate. After applying a phosphor paste or pasting a photosensitive film containing a phosphor, the phosphor film is formed by a method such as a photolithography method in which a predetermined pattern of phosphor film is formed by irradiating a predetermined pattern with light from above. Is formed. In any of these methods, a baking step is required in a final step to remove an organic component such as a binder resin in the process of forming the fluorescent film and fix the fluorescent film on the substrate. In this baking step, baking is usually performed at a temperature of 400 to 600 ° C. However, in this baking step, there has been a problem that the emission luminance of the phosphor in the phosphor film is reduced and so-called luminance degradation is caused.

The degree of luminance degradation during the manufacturing process of such a VUV-excited light-emitting element varies depending on the type of the phosphor used as the phosphor film. BaMgA
l ₁₀ O ₁₇ : Eu or (Ba, Sr) MgAl ₁₀ O
₁₇ : Deterioration of the alkaline earth aluminate phosphor using Eu, Mn or the like as an activator, such as Eu or Mn, is large, and the obtained VUV-excited light emitting device emits blue light or a mixture of three colors. The white light emission luminance of the device used as the blue light emission component of the phosphor was low.

[0008]

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above-mentioned disadvantages, and has little reduction in light emission luminance in the step of forming a fluorescent film of a vacuum ultraviolet ray excited light emitting element such as a PDP or a rare gas discharge lamp. An object of the present invention is to provide a high-luminance phosphor for vacuum ultraviolet rays, a phosphor paste composition, and an ultraviolet-excitation light-emitting device using the same.

[0009]

Means for Solving the Problems To solve the above-mentioned problems, the present inventors coated the surface of a phosphor which emits light by excitation with vacuum ultraviolet rays with various substances, and particularly, the effect of preventing a decrease in luminance during baking. As a result of diligent studies, it was found that by coating the surface of the phosphor with a specific alkaline earth metal compound, it is possible to suppress a decrease in luminance during the manufacturing process of the VUV-excited light emitting device, particularly during the manufacturing process of the fluorescent film,
A phosphor for vacuum ultraviolet rays, a phosphor paste composition, and a vacuum ultraviolet ray excited light emitting device of the present invention having high luminance and less luminance degradation were completed.

That is, the configuration of the present invention is as follows. (1) A phosphor for vacuum ultraviolet radiation, wherein the phosphor particle surface is coated with a strontium (Sr) compound and / or a barium (Ba) compound. (2) The coating amount of the strontium (Sr) compound and / or barium (Ba) compound is 0.005 to 5% by weight based on the phosphor as the total amount of strontium (Sr) and / or barium (Ba). The phosphor for vacuum ultraviolet rays according to the above (1), wherein: (3) The coating amount of the strontium (Sr) compound and / or barium (Ba) compound is 0.03 to 2% by weight based on the phosphor as the total amount of strontium (Sr) and / or barium (Ba). The phosphor for vacuum ultraviolet rays according to the above (2), wherein:

(4) The strontium (Sr) compound and / or barium (Ba) compound is a strontium (Sr) and / or barium (Ba) phosphate. The phosphor for vacuum ultraviolet rays according to any one of 3). (5) The compound according to (1) to (4), wherein the strontium (Sr) compound and / or barium (Ba) compound is a borate of strontium (Sr) and / or barium (Ba). The phosphor for vacuum ultraviolet rays according to any one of the above. (6) The phosphor for vacuum ultraviolet rays according to any one of (1) to (5), wherein the phosphor is an aluminate phosphor.

(7) A phosphor paste composition comprising a phosphor dispersed in a binder resin, wherein the phosphor comprises the phosphor for vacuum ultraviolet rays according to any one of (1) to (6) above. A phosphor paste composition comprising: (8) In a vacuum ultraviolet ray excited light emitting device in which a fluorescent film is formed in a vacuum envelope and a rare gas is sealed, the fluorescent film is for vacuum ultraviolet light according to any one of the above (1) to (6). A vacuum ultraviolet ray excited light emitting device comprising a phosphor.

[0013]

Next, the present invention will be described in more detail. The phosphor for vacuum ultraviolet rays of the present invention can be produced by, for example, several methods as described below.

A) A predetermined amount obtained by dissolving a compound of Sr and / or Ba, such as a halide such as chloride of Sr and / or Ba, a nitrate, a sulfate or a carbonate, in water or a dilute mineral acid. 200 nm in a solution containing Sr ²⁺ and / or Ba ²⁺
A phosphor (a phosphor for vacuum ultraviolet rays) which emits a high luminance upon irradiation with the following VUV is added, sufficiently stirred and mixed, and the slurry is dehydrated and then dried at 100 to 200 ° C. or the slurry is evaporated to dryness. By coating the surface of the phosphor particles with a compound of Sr and / or Ba.

In this case, the phosphor is suspended in water to prepare a phosphor slurry, and a separately prepared solution containing Sr ²⁺ and / or Ba ²⁺ may be added thereto and mixed. A predetermined amount of a compound of Sr and / or Ba may be directly added to the body slurry, mixed and dehydrated.

B) A phosphor for vacuum ultraviolet rays is suspended in water to prepare a phosphor slurry, and the same compound of Sr and / or Ba as used in the production of the phosphor by the above-mentioned method a). Is separately dissolved or directly added to the phosphor slurry, and a predetermined amount of Sr is added to the phosphor slurry.
A phosphor slurry containing ²⁺ and / or Ba ²⁺ is prepared beforehand, and further reacts with Sr ²⁺ or Ba ²⁺ such as boric acid, sodium borate, sodium phosphate, ammonium tungstate, sulfuric acid, etc. A compound capable of forming a precipitate, such as Sr or Ba borate, phosphate, tungstate, sulfate, etc., is added to the slurry, and the mixture is stirred and the Sr and / or Ba compound is added to the phosphor slurry. A method in which a predetermined amount of a compound of Sr and / or Ba is coated on the phosphor surface by forming a precipitate, dehydrating the precipitate as it is on the phosphor surface, and then drying at 100 to 200 ° C.

C) After mechanically mixing a predetermined amount of Sr and / or Ba compounds such as barium phosphate, barium tetraborate, strontium nitrate and barium carbonate with a phosphor for vacuum ultraviolet light, the mixture is mixed with a mixture of about 300-600. A method of coating the surface of the phosphor with a compound of Sr and / or Ba by firing in a temperature range of ° C.

Although it depends on the compound of Sr and / or Ba to be coated, among the above production methods a) to c), in the slurry in which the phosphor is suspended, Sr and / or Ba are used.
The method according to b) above, in which a precipitate of the compound of the formula (1) is formed and the surface of the phosphor in the slurry is deposited and coated with a compound of Sr and / or Ba, the initial luminance of the phosphor (emission luminance before baking) is reduced. Highly, it is possible to reduce a decrease in emission luminance of the phosphor during the step of forming the phosphor film of the vacuum ultraviolet ray excited light emitting element.

In the phosphor for vacuum ultraviolet rays according to the present invention, the compound of Sr and / or Ba to be coated on the surface of the phosphor includes borates, phosphates, silicates, halides, nitrates, and the like of Sr and / or Ba. There are no particular restrictions on the compounds of Sr and / or Ba, such as sulfates and carbonates, but among these compounds, Sr ₃ (B
O ₃ ) ₂ , Sr (BO ₂ ) ₂ , Sr ₂ B ₂ O ₅ , SrB
₄ O ₇ , Ba ₃ (BO ₃ ) ₂ , Ba (BO ₂ ) ₂ , Ba
_{2 B 2 O 5, BaB 4} Sr and / or borate compounds of Ba, such as _{O 7, Sr 2 SiO 4,} Sr 2 SiO 3, Ba 2
General formulas including SiO ₄ , Ba ₂ SiO ₃ , BaSi ₂ O _{5 and the} like, M _x Si _y O _{x + 2y} (where M is S
at least one of r and Ba, and x and y are real numbers of 0 <x and 1 <y, respectively.
And / or Ba silicate compound, Sr ₃ (PO ₄ ) ₂ ,
SrHPO ₄ , Sr (H ₂ PO ₄ ) ₂ , Ba ₃ (P
S such as O ₄ ) ₂ , BaHPO ₄ and Ba (H ₂ PO ₄ ) ₂
A phosphate compound of r and / or Ba is recommended, and among them, strontium tetraborate (SrB ₄ O) is more preferable.
₇ ), it is particularly preferable to use a borate compound of Sr and / or Ba such as barium tetraborate (BaB ₄ O ₇ ). The method for producing the phosphor for vacuum ultraviolet rays of the present invention includes Sr and / or Ba for covering the phosphor surface.
Depending on whether or not the compound of the formula (1) can be dissolved in the phosphor slurry, the surface of the phosphor is coated by appropriately employing the above methods a) to c).

The amount of the Sr and / or Ba compound coated on the phosphor surface depends on the amount of Sr and / or Ba in the compound.
If the amount is less than 0.005 with respect to the phosphor in terms of the amount of the element, almost no improvement in the decrease in emission luminance during baking in the film formation step of the obtained phosphor is recognized. This is not preferable because the initial luminance of the resulting phosphor for vacuum ultraviolet rays is significantly reduced. Accordingly, the coating amount of the Sr and / or Ba compound on the phosphor surface is
It is preferably 0.005 to 5% by weight, more preferably 0.03 to 2% by weight, based on the phosphor in terms of the total weight of Sr and / or Ba in the compound.

The phosphor used in the phosphor for vacuum ultraviolet rays of the present invention is not particularly limited as long as it can emit light with high luminance when irradiated with vacuum ultraviolet rays of 200 nm or less. Body, (Y, Gd)
BO ₃ : Eu, Y ₂ O ₃ : Eu, green light-emitting phosphor, LaPO ₄ : Ce, Tb, Zn ₂ SiO ₄ : Mn,
_{(Ba, Sr, Mg) O} · aAl 2 O 3: Eu, Mn,
BaAl ₁₂ O ₁₉ : Mn, a blue light-emitting phosphor, B
aMgAl ₁₀ O ₁₇ : Eu, (Ba, Sr) MgAl
₁₀ O _17: Eu, Mn, formula _{^(M 1 1-x} Eux)
^{_{O · a (M 2 1-}} y, Mn y) O · (5.5-0.5
a) Al ₂ O ₃ (wherein, M ¹ represents at least one element selected from the group consisting of Ba, Sr and Ca, M ² represents Mg and / or Zn, and a represents 0 <A
≦ 2, where x and y are each 0 <x <1,
0 ≦ y <1), among which (Ba, Sr, Mg) O.aAl ₂ O ₃ : Mn,
BaAl ₁₂ O ₁₉ : Mn, BaMgAl ₁₀ O ₁₇ :
Eu, (Ba, Sr) MgAl ₁₀ O ₁₇ : Eu, M
n, the general formula ^{_{(M 1 1-x Eu x}} ) O · a (M 2 1-y,
Mn _y) O · (5.5-0.5a) aluminate phosphor such as _Al 2 _{O 3,} particularly deterioration of luminance improvement request strong blue emission of _BaMgAl 10 _O 17: aluminate represented by Eu In the case where a phosphor having a phosphor surface coated with a compound of Sr and / or Ba can be used, a decrease in luminance due to baking of the phosphor paste composition can be reduced, and the luminance after baking is baked under the same conditions. Since the brightness becomes higher than that of the phosphor of the present invention, it is more effective.

On the other hand, to produce the phosphor paste composition of the present invention, the phosphor for vacuum ultraviolet rays of the present invention produced as described above is dispersed in a binder resin, and an organic solvent is added thereto. And kneading them sufficiently to adjust to a desired viscosity. As the binder resin used at this time, ethyl cellulose, acrylic resin,
Polystyrene oxide, using a resin such as nitrocellulose, and, as the organic solvent, butyl carbitol,
Solvents such as butyl carbitol acetate, terpineol, butyl acetate, ethyl acetate, and methyl ethyl ketone are used.

The amount of the phosphor for exciting vacuum ultraviolet rays in the phosphor paste composition of the present invention is suitably in the range of 5 to 80% by weight, preferably 20 to 60% by weight. The amount of the binder resin in the binder is suitably in the range of 2 to 90% by weight, preferably 5 to 40% by weight. Further, the addition amount of the solvent in the binder is suitably in the range of 10 to 98% by weight, preferably 60 to 95% by weight. In addition to the binder resin and the solvent, a plasticizer and a stabilizer may be appropriately added to the binder.

The VUV-excited light emitting device of the present invention is the same as a conventional VUV-excited light-emitting device except that the phosphor paste composition of the present invention is used as a phosphor paste composition for forming a fluorescent film. Can be manufactured. For example, in the case of a thin tube lamp, the phosphor paste composition of the present invention is applied in a glass tube of, for example, 4 to 12 mm, dried at 100 to 200 ° C., and then dried at 400 to 8 ° C.
After baking at 00 ° C. for 5 to 30 minutes, nickel electrodes were attached to both ends of the glass, and the inside of the tube was evacuated.
It is manufactured by enclosing a rare gas such as a mixed gas of -Xe 2% or a mixed gas of He 98% -Xe 2% so as to have an internal pressure of about 50 torr.

[0025]

Next, the present invention will be described with reference to examples. Example 1 100 g of (Ba, Eu) MgAl ₁₀ O
₁₇ phosphor was charged into a container containing water to prepare a phosphor slurry, and 0.1 phosphor separately prepared in this phosphor slurry.
38 g of sodium tetraborate (Na ₂ B ₄ O ₇ · 10H ₂
O) was added to make a total of about 300 ml of a solution, and a separately prepared solution containing 0.26 g of barium nitrate {Ba (NO ₃ ) ₂ } was added dropwise thereto.
After stirring for 5 minutes and mixing well, dehydration and drying were performed to produce a phosphor for vacuum ultraviolet rays having barium borate coated on the phosphor surface.

Example 2 0.38 g of Na ₂ B ₄ O ₇
3.8 g of Na instead of the solution containing 10H ₂ O
Using a solution containing _{2 B 4 O 7 · 10H 2} O, also,
In the same manner as in Example 1 except that a solution containing 2.6 g of Ba (NO ₃ ) ₂ was used instead of the solution containing 0.26 g of Ba (NO ₃ ) ₂ , the surface of the phosphor was changed to barium borate. To produce a phosphor for vacuum ultraviolet rays.

Example 3 100 g of (Ba, Eu) M
gAl ₁₀ O ₁₇ phosphor is charged into a container containing water to prepare a phosphor slurry, and a colloidal SiO ₂ solution (SiO ₂ content 2
0% by weight) to give a total solution of about 300 ml, and a solution containing separately prepared 0.53 g of barium acetate {Ba (CH ₃ COO) ₂ .H ₂ O}. Was dropped, stirred for 15 minutes, thoroughly mixed, then dehydrated and dried to produce a phosphor for vacuum ultraviolet rays having the phosphor surface coated with barium silicate.

Example 4 2.0 g of colloidal Si
3.9 g of a colloidal SiO ₂ solution (SiO ₂ content) was used instead of the O ₂ solution (SiO ₂ content),
Instead of the solution containing 0.53 g of Ba (CH ₃ COO) ₂ .H ₂ O, 3.6 g of Ba (CH ₃ COO) ₂ .H
_A phosphor for vacuum ultraviolet rays having a phosphor surface coated with barium silicate was used in the same manner as in Example 3 except that a solution containing ₂ O was used.

Example 5 100 g of (Ba, Eu) M
gAl ₁₀ O ₁₇ phosphor is charged into a container containing water to prepare a phosphor slurry, and 0.063 g of Na ₃ PO separately prepared therein is stirred while the phosphor slurry is stirred.
₄ · 12H ₂ to about 30 the whole solution by adding a containing O
0 ml of the solution, and 0.068 prepared separately in it.
g of barium acetate {Ba (CH ₃ COO) ₂ .H ₂ O}
Was dropped, stirred for 15 minutes, mixed well, then dehydrated and dried to produce a phosphor for vacuum ultraviolet rays having the phosphor surface coated with barium phosphate.

Example 6 0.063 g of Na ₃ PO ₄
1.3 g of Na instead of the solution containing 12H ₂ O
Using a solution containing ₃ PO ₄ .12H ₂ O;
Instead of a solution containing 0.068 g of Ba (CH ₃ COO) ₂ .H ₂ O, 1.4 g of Ba (CH ₃ COO) _2.
A phosphor for vacuum ultraviolet rays having a phosphor surface coated with barium phosphate was produced in the same manner as in Example 5, except that a solution containing H ₂ O was used.

Example 7 0.063 g of Na ₃ PO ₄
2.5 g of Na instead of the solution containing 12H ₂ O
Using a solution containing ₃ PO ₄ .12H ₂ O;
Instead of a solution containing 0.068 g of Ba (CH ₃ COO) ₂ .H ₂ O, 2.7 g of Ba (CH ₃ COO) _2.
A phosphor for vacuum ultraviolet rays having a phosphor surface coated with barium phosphate was produced in the same manner as in Example 5, except that a solution containing H ₂ O was used.

Example 8 0.38 g of Na ₂ B ₄ O ₇
0.19 g of Na ₂ instead of the solution containing H ₂ O
Using a solution containing B ₄ O ₇ · 10H ₂ O;
Instead of the solution containing 0.26 g of Ba (NO ₃ ) ₂ , 0.1 g of strontium nitrate @ Sr (N
Except for using the solution containing O ₃ ) ₂ }, the present invention for vacuum ultraviolet rays having the phosphor surface coated with strontium borate was produced in the same manner as in Example 1.

Example 9 0.38 g of Na ₂ B ₄ O ₇
1.9 g of Na instead of the solution containing 10H ₂ O
Using a solution containing _{2 B 4 O 7 · 10H 2} O, 0.2
Instead of a solution containing 6 g of Ba (NO ₃ ) ₂ , 1.
Except for using a solution containing 1 g of strontium nitrate {Sr (NO _{3) 2} }, the present invention for vacuum ultraviolet rays having a phosphor surface coated with strontium borate was produced in the same manner as in Example 1.

Example 10 2.0 g of colloidal S
_2. Instead of iO ₂ solution (SiO ₂ content 20% by weight)
9 g of colloidal SiO ₂ solution (SiO ₂ content 20
0.53 g of Ba (CH ₃ COO) ₂
- except that instead of the solution containing H 2 _O using a solution containing strontium nitrate _{4.3g {Sr (NO 3) 2} } in the same manner as in Example 3, the coating silicate strontium surface of the phosphor The manufactured phosphor for vacuum ultraviolet rays was manufactured.

Example 11 0.063 g of Na ₃ PO
Using a solution containing _Na 3 _PO 4 · 12H ₂ O of 0.034g instead a solution containing ₄ · 12H ₂ O, 0.
In the same manner as in Example 5 except that a solution containing 0.028 g of Sr (NO ₃ ) ₂ was used instead of 068 g of Ba (CH ₃ COO) ₂ .H ₂ O, strontium phosphate was applied to the phosphor surface. A coated phosphor for vacuum ultraviolet light was manufactured.

Example 12 0.063 g of Na ₃ PO
0.84g of N instead of a solution containing ₄ · 12H ₂ O
Using a solution containing a ₃ PO ₄ .12H ₂ O, 0.0
Instead of 68 g of Ba (CH ₃ COO) ₂ .H ₂ O, 0.
In the same manner as in Example 5 except that a solution containing 7 g of Sr (NO ₃ ) ₂ was used, a phosphor for vacuum ultraviolet rays having a phosphor surface coated with strontium phosphate was produced.

Example 13 0.063 g of Na ₃ PO
3.4g of Na in place of a solution containing ₄ · 12H ₂ O
Using a solution containing ₃ PO ₄ .12H ₂ O, 0.06
2.8 instead of 8 g Ba (CH ₃ COO) ₂ .H ₂ O
In the same manner as in Example 5 except that a solution containing g of Sr (NO ₃ ) ₂ was used, a phosphor for vacuum ultraviolet rays having a phosphor surface coated with strontium phosphate was produced.

Comparative Example 1 For comparison, Examples 1 to 1 were used.
Sr and / or on the surface used to produce the phosphor of No. 3
Or, the compound of Ba is not coated at all (Ba, E
u) The MgAl ₁₀ O ₁₇ phosphor itself was separately prepared as the phosphor for vacuum ultraviolet rays of Comparative Example 1.

Comparative Example 2 100 g of (Ba, Eu) M
gAl ₁₀ O ₁₇ 25 g of a colloidal SiO ₂ solution (SiO ₂ content: 20% by weight) was added to a water slurry of the phosphor, and the solution was stirred for 15 minutes and evaporated to dryness to obtain silicon oxide. Produced a phosphor for vacuum ultraviolet rays, the surface of which was coated.

Comparative Example 3 0.063 g of Na ₃ PO ₄
1.2 g of Na instead of the solution containing 12H ₂ O
Using a solution containing ₃ PO ₄ .12H ₂ O;
Instead of the solution containing 0.068 g of Ba (CH ₃ COO) ₂ .H ₂ O, 1.1 g of calcium nitrate @ Ca
(NO 3) except for using a solution containing ₂ · _{4H 2 O},} the same procedure as in Example 5, the calcium phosphate was prepared VUV phosphor coated on the phosphor surface.

Example 14 30 g of the phosphor for vacuum ultraviolet light produced in Example 1 was weighed, and 25 g of an ethyl cellulose resin, 10 g of butyl carbitol and 53 g of butyl carbitol acetate were mixed with each other. A phosphor paste composition was manufactured by kneading.

Embodiments 15 to 26 Similar to Embodiment 14 except that the phosphors for vacuum ultraviolet rays of Examples 2 to 13 are used instead of the phosphors for vacuum ultraviolet rays of Example 1 used in Embodiment 14. Thus, the phosphor paste compositions of Examples 15 to 26 were produced.

Comparative Examples 4 to 6 Comparative Example 4 was carried out in the same manner as in Example 14 except that the vacuum ultraviolet fluorescent materials of Comparative Examples 1 to 3 were used instead of the vacuum ultraviolet fluorescent material of Example 1. To 6 were prepared.

Example 27 The phosphor for vacuum ultraviolet rays of Example 4 was weighed in an amount of 30 g, and 25 g of nitrocellulose resin and 45 g of butyl acetate were mixed and kneaded to prepare a phosphor paste. This phosphor paste is applied to a glass tube having an outer diameter of 4 mm and dried at 120 ° C. for 60 minutes.
Baking was performed at 0 ° C. for 10 minutes to obtain a phosphor-coated tube. Nickel electrodes were attached to both ends of the obtained phosphor-coated tube, and the inside of the tube was evacuated to a vacuum.
Torr was sealed to obtain a vacuum ultraviolet ray excited light emitting device. An AC voltage is applied to the obtained VUV-excited light-emitting element to emit light, and the luminance / y at the center of the tube of the VUV-excited light-emitting element is expressed by:
Was measured.

COMPARATIVE EXAMPLE 7 The procedure of Example 27 was repeated, except that the phosphor for vacuum ultraviolet rays of Comparative Example 1 was used instead of the phosphor for vacuum ultraviolet rays of Example 4. An element was obtained. The obtained VUV-excited light-emitting device was allowed to emit light in the same manner as in Example 27, and the luminous efficiency (luminance / y) at the center of the tube of the VUV-excited light-emitting device was measured. Next, the following evaluations were performed on the vacuum ultraviolet ray excited phosphor and the phosphor paste of the above Examples and Comparative Examples, and the results are shown in Table 1.

<Quantification of the coating on the phosphor surface> Determination of the Sr and / or Ba compound in the surface coating of each phosphor for vacuum ultraviolet rays is performed by immersing the phosphor in a solution containing a mineral acid and stirring. Then, the coating adhering to the phosphor surface was dissolved and peeled off, and the analysis value of the (Ba, Eu) MgAl ₁₀ O ₁₇ phosphor of Comparative Example 1 having no coating subjected to the same treatment was used. Was used as a reference sample and quantified using an ICP (inductively coupled high frequency plasma) analyzer. In Table 1, the coating amount () is the weight percentage (Wt) of the metal (Sr and / or Ba in each example, Ca in Comparative Example 3) contained in the coating with respect to the phosphor determined by the above method. .
%).

<Evaluation of Luminance Degradation> In order to evaluate the degree of luminance deterioration in the baking step of the phosphor for vacuum ultraviolet light according to the present invention, each sample was irradiated with 146 nm vacuum ultraviolet light, and the luminous efficiency and luminescent color at that time were irradiated. The luminous efficiencies before and after baking were determined by measuring the degree, and the comparison was made.

In this embodiment, each of the samples is a (Ba, Eu) MgAl ₁₀ O ₁₇ phosphor which emits blue light or a coating film made of this phosphor, and the luminance of the blue light-emitting phosphor is chromaticity y. Since the value greatly changes in proportion to the value, it is more appropriate to use the value obtained by dividing the luminance by the y value (luminance / y), which simply represents the relative luminous efficiency. The value (luminance / y) obtained by dividing the emission luminance of the sample by the y value of the chromaticity is referred to as the luminous efficiency of each sample.
The degree of luminance degradation of each phosphor was evaluated by the relative value ratio of.

Further, a phosphor paste composition comprising each phosphor for vacuum ultraviolet rays is applied to a glass plate at a thickness of 0.5 mm to form a coating film.
After drying for 0 minutes and further baking at 500 ° C. for 30 minutes, the luminous efficiency of this coating film was determined and defined as the luminous efficiency of each phosphor after baking.

In Table 1, the luminous efficiency () and the luminous efficiency () after baking are shown for each of the phosphors for vacuum ultraviolet rays, respectively, before the baked phosphor is baked and for the paste formed of the phosphor. And the luminous efficiency after baking is formed. Further, the luminance maintenance ratio (/) and the luminance improvement ratio () are respectively the luminous efficiency after baking with respect to the luminous efficiency before baking of the phosphor and Comparative Example 1 after baking of each phosphor.
Is the relative ratio of the luminous efficiency of each of the respective phosphors to the phosphor of the present invention.

All the luminous efficiencies of the respective samples were shown as relative values when the value of the phosphor of Comparative Example 1 before baking was set to 100.

[0052]

[Table 1]

As can be seen from Table 1, Ba and / or S
The phosphor for vacuum ultraviolet rays of the present invention coated with the compound of r (Examples 1 to 13) is a phosphor having no surface coated (Comparative Example 1) or a compound other than the compound of Ba and / or Sr. Compared with the phosphors coated on the surface (Comparative Examples 2 and 3), the luminous efficiency () after paste-forming and baking treatment is high, and the luminance maintenance ratio (/) is good. Understand.

Although not described in Table 1, even when each of the phosphors for vacuum ultraviolet rays is baked in a powder state without being pasted, the surface of the present invention is coated with a compound of Ba and / or Sr. (Ba, Eu) MgAl
_{The 10} O ₁₇ phosphor was obtained by comparing Ba and / or Sr of Comparative Example 1.
(Ba, Eu) MgA not coated with
Compared with l ₁₀ O ₁₇ phosphor, all luminous efficiency (luminance / y
Value) was high, and the decrease in luminous efficiency due to the baking treatment was small compared to the phosphor of Comparative Example 1.

The luminous efficiency (luminance / y value) of the VUV-excited light emitting device of Example 27 and the VUV-excited light-emitting device of Comparative Example 7 was measured and compared. (Luminance / y value) is 100
%, The (luminance / y value) of the VUV-excited light-emitting device of Example 27 is 115%, and the VUV-excited light-emitting device of the present invention of Example 27 is more than the VUV-excited light-emitting device of Comparative Example 7. Light-emitting efficiency (luminance / y value) was higher than that of the light-emitting element.

[0056]

As described above, the phosphor for vacuum ultraviolet rays and the phosphor paste composition of the present invention have the above-mentioned constitutions, so that the reduction in luminous efficiency due to baking is small and the luminance retention rate is high. The ultraviolet-excitation light-emitting element also has a small decrease in luminance during the manufacturing process, and the luminous efficiency is remarkably improved.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01J 11/02 H01J 11/02 B 61/46 61/46 (72) Inventor Takayuki Hisamune Narita, Odawara-shi, Kanagawa Prefecture 1060 F-term in Kasei Optonics Odawara Plant (reference) 4H001 CA01 CC12 XA08 XA12 XA13 XA56 YA63 5C040 GG07 GG08 KA03 KB06 KB28 MA03 MA10 5C043 AA02 AA07 BB09 EA16 EB01 EB07 EC08

Claims (8)

[Claims] 1. A phosphor for vacuum ultraviolet rays, wherein the surface of the phosphor particles is coated with a compound of strontium (Sr) and / or a compound of barium (Ba). 2. The coating amount of the strontium (Sr) compound and / or barium (Ba) compound is 0.005 to 5 with respect to the phosphor as the total amount of strontium (Sr) and / or barium (Ba). 2. The phosphor for vacuum ultraviolet rays according to claim 1, wherein the phosphor is contained in a percentage by weight. 3. The coating amount of the strontium (Sr) compound and / or barium (Ba) compound is 0.03 to 2 with respect to the phosphor as a total amount of strontium (Sr) and / or barium (Ba). 3. The phosphor for vacuum ultraviolet rays according to claim 2, wherein the content is by weight. 4. 4. The method according to claim 1, wherein the strontium (Sr) compound and / or barium (Ba) compound is a strontium (Sr) and / or barium (Ba) phosphate. The phosphor for vacuum ultraviolet rays according to claim 1. 5. The strontium (Sr) compound and / or barium (Ba) compound is a borate of strontium (Sr) and / or barium (Ba). The phosphor for vacuum ultraviolet rays according to claim 1. 6. The phosphor for vacuum ultraviolet rays according to claim 1, wherein the phosphor is an aluminate phosphor. 7. A phosphor paste composition obtained by dispersing a phosphor in a binder resin, wherein the phosphor comprises the phosphor for vacuum ultraviolet rays according to any one of claims 1 to 6. Phosphor composition. 8. A vacuum ultraviolet ray excited light emitting device in which a fluorescent film is formed in a vacuum envelope and a rare gas is sealed, wherein the fluorescent film is the vacuum ultraviolet light according to any one of claims 1 to 6. A vacuum ultraviolet ray excited light emitting device comprising a phosphor for use.