Compositions – Inorganic luminescent compositions – Compositions containing halogen; e.g. – halides and oxyhalides
Reexamination Certificate
2001-02-26
2003-03-04
Koslow, C. Melissa (Department: 1755)
Compositions
Inorganic luminescent compositions
Compositions containing halogen; e.g., halides and oxyhalides
C313S467000, C313S482000, C313S486000, C313S495000
Reexamination Certificate
active
06527978
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a phosphor suitable for a vacuum ultraviolet ray-exciting light-emitting element such as plasma display panel (hereinafter, abbreviated as PDP ), rare gas lamp and the like, and a vacuum ultraviolet ray-exciting light-emitting element using this phosphor.
2. Description of Related Art
Recently, there is increasing development on vacuum ultraviolet ray-exciting light-emitting elements having a mechanism in which a phosphor is excited to emit light by vacuum ultraviolet ray which is radiated by rare gas discharge. Typical examples thereof include the development of PDP. Though cathode ray tubes (CRT) and color liquid crystal displays have difficulty in increasing the size of a screen, PDP is a flat panel display enabling this size increase and expected to be used for displays in public space and large screen televisions. PDP is a display constituted by placing a lot of minute discharge spaces (hereinafter, sometimes referred to as “display cell”) in the form of a matrix. In each display cell, a discharge electrode is provided, and on the inner wall of each display cell, a phosphor is applied. In the space of each display cell, a rare gas such as He—Xe, Ne—Xe, Ar and the like is sealed, and by applying voltage on a discharge electrode, electric discharge occurs in the rare gas and vacuum ultraviolet ray is discharged. By this vacuum ultraviolet ray, a phosphor is excited and visible light is emitted. An image is displayed by assigning the position of an emitting display cell. By using phosphors which emit lights of three primary colors of light, blue, green and red, respectively, full color display can be effected.
As a vacuum ultraviolet ray-exciting light-emitting element other than PDP, a rare gas lamp is exemplified. The rare gas lamp is a lamp emitting light by a mechanism in which vacuum ultraviolet ray is generated by discharge in a rare gas and the vacuum ultraviolet ray is converted to visual light by a phosphor. Since a rare gas lamp uses no mercury, it is noticed from the standpoint of environmental problems.
A phosphor which is excited by vacuum ultraviolet ray radiated by discharge in a rare gas has already been suggested, and as a blue phosphor, BaMgAl
10
O
17
:Eu is exemplified, as a green phosphor, Zn
2
SiO
4
:Mn is exemplified, and as a red phosphor, (Y,Gd)BO
3
:Eu is exemplified. However, for full color PDP, a phosphor excellent in the life property of brilliance is desired. Particularly in a blue light emitting phosphor, a phosphor excellent in the life property of brilliance is intensively desired.
An object of the present invention is to provide a phosphor excellent in the life property of brilliance, used for vacuum ultraviolet ray-exciting light-emitting elements such as PDP and the like, and a vacuum ultraviolet ray-exciting light-emitting element using this phosphor.
The present inventors have intensively studied, under such conditions, for solving the above-mentioned problems, and resultantly found that among phosphors of aluminates containing Eu as an activator, a compound having a magnetoplumbite structure is useful as a phosphor for a vacuum ultraviolet ray-exciting light-emitting element, particularly, as a blue phosphor, leading to completion of the present invention.
SUMMARY OF THE INVENTION
Namely, the present invention provides the following [1]-[6].
[1] A phosphor for a vacuum ultraviolet ray-exciting light-emitting element, comprising Eu as an activator, and aluminates having a magnetoplumbite structure.
[2] The phosphor for a vacuum ultraviolet ray-exciting light-emitting element according to [1], wherein the aluminates contain a compound of the composition formula M
1−a
Eu
a
Al
12
O
19
wherein M represents one or more elements selected from the group consisting of Ca, Sr and Ba, and the formula satisfies 0.003≦a≦0.5.
[3] The phosphor for a vacuum ultraviolet ray-exciting light-emitting element according to [1], wherein the aluminates contain a compound of the composition formula Ba
1−a
Eu
a
MgAl
6
O
27
wherein the formula satisfies 0.003≦a≦0.5.
[4] The phosphor for a vacuum ultraviolet ray-exciting light-emitting element according to [1], wherein the aluminates contain a compound of the composition formula Ba
1−a
Eu
a
MgAl
6
O
11
wherein the formula satisfies 0.003≦a≦0.5.
[5] The phosphor for a vacuum ultraviolet ray-exciting light-emitting element according to [1], wherein the aluminates contain a compound of the composition formula (Ba
1−a
Eu
a
)
3
Mg
2
Al
24
O
41
wherein the formula satisfies 0.003≦a≦0.5.
[6] A vacuum ultraviolet ray-exciting light-emitting element containing the phosphor for a vacuum ultraviolet ray-exciting light-emitting element according to [1].
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be illustrated in detail below.
In general, an activator causes an effect as a phosphor by substituting with a part of constituent atoms without changing the structure of a substrate crystal. A phosphor for a vacuum ultraviolet ray-exciting light-emitting element of the present invention is a phosphor having as a substrate a compound particularly having a magnetoplumbite crystal structure among aluminates, and containing Eu as an activator.
As aluminates which are substrates having a magnetoplumbite structure, specifically, MAl
12
O
19
(wherein, M represents one or more elements selected from the group consisting of Ca, Sr and Ba), BaMg
2
Al
16
O
27
, BaMgAl
6
O
11
and Ba
3
Mg
2
Al
24
O
41
are preferable. A metal ion in these aluminates having a magnetoplumbite structure can be substituted with an activator, Eu (divalent) to give a phosphor for a vacuum ultraviolet ray-exciting light-emitting element containing the Eu.
Specifically, as compounds obtained by using as a substrate aluminates of the formula: MAl
12
O
19
(wherein, M represents one or more elements selected from the group consisting of Ca, Sr and Ba) and substituting M in the formula with an activator, Eu (divalent), there are listed phosphors for a vacuum ultraviolet ray-exciting light-emitting element of the formula: M
1−a
Eu
a
Al
12
O
19
(wherein, M represents one or more elements selected from the group consisting of Ca, Sr and Ba, and 0.003≦a≦0.5.).
Further, as compounds obtained by using as a substrate aluminates of the formula: BaMg
2
Al
16
O
27
and substituting Ba in the formula with an activator, Eu (divalent), there are listed phosphors for a vacuum ultraviolet ray-exciting light-emitting element of the formula: Ba
1−a
Eu
a
Mg
2
Al
16
O
27
(0.003≦a≦0 5.).
Furthermore, as compounds obtained by using as a substrate aluminates of the formula: BaMgAl
6
O
11
and substituting Ba in the formula with an activator, Eu (divalent), there are listed phosphors for a vacuum ultraviolet ray-exciting light-emitting element of the formula: Ba
1−a
Eu
a
MgAl
6
O
11
(0.003≦a≦0.5.).
Still more, as compounds obtained by using as a substrate aluminates of the formula: Ba
3
Mg
2
Al
24
O
41
and substituting Ba in the formula with an activator, Eu (divalent), there are listed phosphors for a vacuum ultraviolet ray-exciting light-emitting element of the formula: (Ba
1−a
Eu
a
)
3
Mg
2
Al
24
O
41
(0.003≦a≦0.5.).
A phosphor for a vacuum ultraviolet ray-exciting light-emitting element of the present invention can also be applied to phosphors excited by ultraviolet rays out of the vacuum ultraviolet range, X ray and electron beam, and to elements using the same.
A method of producing a phosphor of the present invention is not particularly restricted, and can be produced by known methods such as, for example, a method disclosed in JP-A No. 10-53760. In general, it can be produced by compounding raw materials so as to provide a given composition and calcining the composition.
A phosphor of the present invention can be obtained by a method in which raw ma
Endo Tadashi
Miyazaki Susumu
Ono Keiji
Ueda Kyota
Koslow C. Melissa
Sumitomo Chemical Company Limited
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