JPH0841454A - Luminescence composition of rare earth oxide-sulfide fluorescence body - Google Patents

Abstract

PURPOSE:To obtain a luminescence composition of a rear earth oxide-sulfide fluorescence body containing no Cd and capable of developing red luminescence having high brightness of a practical level by low-velocity electron-ray excitation of accelerating voltage of less than several kilo volt, especially less than several hundred volt. CONSTITUTION:This is a luminescence composition of a rear earth oxide-sulfide fluorescence body by compounding or attaching an oxide-sulfide yttrium fluorescence body expressed by the following composition formula with a conductive material. (Y1-x-y-z, Lax, Lny, Tbz)2O2S:kM (Ln is Eu and/or Sm; M is at least one selected from Si, Ge, Sn, Pb, Ti, Zr and Hf; x, y, z and k are numbers each satisfying the following relations 0.001<=x<=0.035, 0.001<=y<=0.20, z=0 or 10<-6=z<=10<-4> and 0<k<=0.5, respectively).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rare earth oxysulfide phosphor luminescent composition which emits red light with high brightness when excited by a slow electron beam having an accelerating voltage of several kV, particularly several hundreds V or less.

[0002]

2. Description of the Related Art Conventionally, the acceleration voltage is several KV or less, especially
Light emission with high brightness by low-speed electron beam excitation of several hundreds V or less
ZnO: Zn phosphor that emits blue-green light as a light-emitting material
The emission color varies from blue to green and yellow depending on the amount of CdS and solid solution.
Color, and even red can be changed at will (Z
n_1-x,Cd_x) S: Ag (0 ≦ x ≦ 1) phosphor in In₂
O ₃, ZnO, SnO₂Mix or attach conductive substances such as
The luminescent composition thus obtained is well known. These luminescent materials
A fluorescent display tube using a fluorescent material as a fluorescent film is a VTR or an electronic
Widely used as a display element for electrical products such as sensors and in-vehicle
Has been done.

[0003]

However, among these light emitting materials, a light emitting composition using a (Zn _1-x, Cd _x ) S: Ag phosphor is a ZnS: Ag phosphor (where x = Since it contains Cd which is a specific chemical substance except (in case of 0),
In the production and handling of the luminescent composition, it is necessary to take pollution prevention measures. Also, when discarding used products for fluorescent display tubes, they are handled as industrial waste, so a lot of costs are required for disposal. There was such a problem.

By the way, among phosphors used as a light emitting composition by mixing or adhering with a conductive substance, the main phosphors emitting blue, green and yellow light, which do not contain Cd, are Zn.
In addition to S: Ag phosphor (blue emission) and ZnO: Zn phosphor (blue green emission), ZnS: Cu, Al (green emission),
ZnS: Au, may or Al (yellow light), and Yu is a red-emitting phosphor - europium with Katsusan sulfide yttrium phosphor _{(Y 2 O 2 S: Eu} ) is but a representative, Y ₂
Since a red light-emitting composition composed of O ₂ S: Eu phosphor and a conductive substance has low emission brightness, when it is used as a fluorescent film of a fluorescent display tube, the visibility is poor and the practical level is reached. Not not. Therefore, it has been desired to develop a light-emitting material that does not contain Cd and that emits red light with higher brightness by low-speed electron beam excitation.

The present invention solves the above problems and is a rare earth acid containing no Cd, which exhibits a high-luminance red light emission of a practical level when excited by a slow electron beam having an accelerating voltage of several KV or less, particularly several hundred V or less. It is intended to provide a sulfide phosphor light emitting composition.

[0006]

The present invention is as follows. (1) A rare earth oxysulfide phosphor light-emitting composition obtained by mixing or adhering a conductive substance to the yttrium oxysulfide phosphor represented by the following composition formula. _{(Y 1-xy, La x} , Ln y) 2 O 2 S: kM ( where, Ln is Eu and / or Sm, M is Si, Ge,
At least one of Sn, Pb, Ti, Zr, and Hf, and x, y, and k are 0.001 ≦ x ≦ 0.
035, 0.001 ≦ y ≦ 0.20, and 0 <k ≦
It is a number that satisfies 0.5)

(2) A rare earth oxysulfide phosphor light-emitting composition obtained by mixing or adhering a conductive substance to the yttrium oxysulfide phosphor represented by the following composition formula. (Y _1-xyz, La _x, Lny _, Tb _z ) ₂ O ₂ S: kM (where Ln is Eu and / or Sm, M is Si, Ge,
At least one of Sn, Pb, Ti, Zr, and Hf, and x, y, z, and k are each 0.001 ≦ x ≦
0.035, 0.001 ≤ y ≤ 0.20, 10 ^-6 ≤ z ≤
It is a number that satisfies the condition of 10 ^-4 and 0 <k ≦ 0.5)

(3) The above k value is 5 × 10 ⁻⁶ ≦ k ≦ 5 × 10
^The light emitting composition of the rare earth oxysulfide phosphor according to (1) or (2) above, which is in the range of ^-2 .

(4) A mixture obtained by mixing 5 to 30% by weight of the conductive substance and the yttrium oxysulfide-based phosphor with respect to the total amount of the rare earth oxysulfide phosphor light-emitting composition.
The rare earth oxysulfide phosphor light-emitting composition according to any one of (1) to (3).

(5) The above-mentioned (1) to 25% by weight of the above-mentioned electroconductive substance deposited on the surface of the above-mentioned yttrium oxysulfide-based phosphor with respect to the total amount of the above-mentioned rare earth oxysulfide phosphor luminescent composition. 1) The rare earth oxysulfide phosphor light-emitting composition according to any one of 1) to (3).

[0011]

The inventors of the present invention have previously proposed that a yttrium oxyphosphor containing a specific amount of lanthanum (La) (hereinafter
We have proposed a light-emitting composition obtained by mixing or adhering a conductive substance to "yttrium oxysulfide-based phosphor" (see Japanese Patent Application No. 6-103752). Further, for the above-mentioned purpose, when further research was conducted on a fluorescent substance to be mixed with or adhered to a conductive substance, a yttrium oxysulfide-based fluorescent substance was added to Si, Ge, Sn, Pb, Ti, Zr, H
When a specific tetravalent metal such as f is contained, the emission brightness hardly changes under the high-speed electron beam excitation with an acceleration voltage of several KV or more, but a conductive substance is mixed or attached to this phosphor to accelerate the phosphor. It has been found that when excited by a low-speed electron beam having a voltage of several kV or less, it emits light with high brightness.

The method for producing the luminescent composition of the present invention will be described in detail below. While the is a component of the luminescent composition of the present invention _{(Y 1-xy, La x} , Ln y) 2 O 2 S: kM phosphor,
And (Y _1-xyz, La _x, Lny _, Tb _z ) ₂ O ₂ S:
kM phosphors, respectively Y compounds such predetermined amount of Y ₂ O _3, La compounds such La ₂ O _3, Eu compounds such Eu ₂ O _3, Sm compounds such Sm ₂ O ₃ and Tb ₂ O _3, etc. Of T
b compound and SiO ₂ , GeO ₂ , SnO ₂ , Pb
Si, Ge such as O ₂ , TiO ₂ , ZrO ₂ and HfO ₂ ,
In addition to at least one compound of Sn, Pb, Ti, Zr and Hf, a sulfurizing agent such as sulfur (S) and Na ₂ CO ₃ ,
It can be produced by mixing a fluxing agent such as K ₃ PO _{4 and} firing at a temperature of 1000 to 1300 ° C. for 30 to 120 minutes.

These (Y_1-xy,La_x,Ln_y)
₂O₂S: kM phosphor, or (Y _1-xyz,La_x,Ln
_y,Tb_z)₂O₂S: kM phosphor mixed with conductive material
Has a high emission brightness when it is attached to form a luminescent composition.
To maintain (Y_1-xy,La_x,Ln_y)₂O₂S:
La content (x) and Ln content of the kM phosphor
(Y) is 0.001 ≦ x ≦ 0.035 and 0.001
≦ y ≦ 0.20, preferably 0.005 ≦ x ≦ 0.03
The range of 0 and 0.01 ≦ y ≦ 0.10 is suitable.
(Y_1-xyz,La_x,Ln_y,Tb_z)₂O₂S: kM
La content (x), Ln content in case of fluorescent material
The content (z) of (y) and Tb is 0.001 ≦ x ≦
0.035, 0.001 ≦ y ≦ 0.20 and 1 × 10^-6
≦ z ≦ 1 × 10 ^-Four, Preferably 0.005 ≦ x ≦ 0.0
30, 0.01 ≦ y ≦ 0.10 and 2 × 10^-6≦ z ≦ 5
× 10^-FiveThe range is suitable.

The conductive substance, which is the other constituent of the light emitting composition of the present invention, is In ₂ O ₂ , ZnO, SnO ₂ , TiO ₂ , WO ₃ , or N, as in the case of the conventional light emitting composition.
Conductive metal oxides such as b ₂ O ₅ and CdS, In ₂ S, L
Although a conductive metal sulfide such as i ₂ S or Cu ₂ S may be used, it is preferable to use a conductive metal oxide from the viewpoint of the emission brightness of the resulting light emitting composition.
_It is more preferable to use ₂ O ₃ .

These conductive substances can be simply mechanically mixed with the phosphor by any mixing means, or can be attached to the surface of the phosphor using a binder or the like to obtain the light emitting composition of the present invention. Specifically, a method using an adhesive such as gelatin or gum arabic (Japanese Patent Publication No. 54-3677),
Conductivity on the surface of the phosphor particles by a method such as electrostatic coating (Japanese Patent Publication No. 54-44275) or a method using an organic binder such as ethylene cellulose, nitrocellulose (Japanese Patent Publication No. 62-33266). A substance can be attached.

The mixing ratio of the conductive material is determined in consideration of the emission brightness of the light emitting composition. When the fluorescent substance and the conductive substance are simply mixed, the mixed amount of the conductive substance is appropriately in the range of 5 to 30% by weight, preferably 10 to 25% by weight based on the total amount of the light emitting composition. On the other hand, when the conductive substance is attached to the surface of the phosphor, the amount of the attached substance is appropriately 1 to 25% by weight, preferably 5 to 20% by weight based on the total amount of the light emitting composition.

FIG. 1 shows Sn in the light emitting composition of the present invention.
3 is a graph showing the relationship between the content of R and the relative emission brightness. The curve A shows that (Y _0.957 , La _0.02 , Eu _0.023 ) ₂ O ₂ S: k using Eu as an activator and containing Sn.
The Sn content (k) and the emission brightness when a light emitting composition obtained by mixing Sn phosphor with 18% In ₂ O ₃ as a conductive substance was irradiated with a low-speed electron beam with an acceleration voltage of 60V. It is a graph which shows the correlation of. A curve B shows the Sn content (k) contained in the phosphor and the emission brightness when the phosphor with the In ₂ O ₃ mixture omitted is irradiated with a high-speed electron beam with an acceleration voltage of 12 KV. It is a graph which illustrates the relationship of. The relative emission brightness in the figure is shown as a relative value when the emission brightness of the Sn-free (Y _0.957 , La _0.02 , Eu _0.023 ) ₂ O ₂ S phosphor is 100, and the relative emission brightness of curves A and B is shown. Absolute values cannot be compared with each other.

As can be seen from FIG. 1, the phosphor (curve B) in which the mixing of In ₂ O ₃ is omitted has almost no change in the emission luminance under the high-speed electron beam excitation even if the Sn content (k) changes. On the other hand, a light-emitting composition obtained by mixing In ₂ O ₃ with this phosphor has a Sn content (k) of 5 per 1 mol of the yttrium oxysulfide-based phosphor when excited by a slow electron beam.
When it is less than or equal to × 10 ⁻¹ gram atom, that is, in the range of 0 <k ≦ 0.5, the luminescent brightness is improved as compared with the light emitting composition using the phosphor containing no Sn (k = 0), and particularly, the Sn content is included. It can be seen that when the amount (k) is in the range of 5 × 10 ⁻⁶ ≦ k ≦ 5 × 10 ⁻² , the emission brightness is further improved.

FIG. 1 shows an example of a light-emitting composition using a yttrium oxysulfide-based phosphor containing Sn as a tetravalent metal element, but Si, Ge, Pb,
The emission composition using the yttrium oxysulfide-based phosphor containing Ti, Zr, and Hf also has improved emission luminance in the same range as Sn, and exhibits higher emission emission under low-speed electron beam excitation. confirmed.

Further, in FIG. 1, (Y_0.957, La_0.02, E
u_0.023)₂O₂18% by weight of In in S: kSn phosphor
₂O₃Sn content in a luminescent composition obtained by mixing
Regarding the relationship between (k) and the emission brightness under low-speed electron beam excitation,
In,₂O₃When the mixing amount of
n₂O₃When attached to phosphor, yttrium oxysulfide
Eu activation amount (y) and La content (x) of the aluminum-based phosphor
If In is changed, In₂O₃Use a conductive substance other than
And as a phosphor (Y_1-xyzLa _x, Ln
_yTb_z)₂O₂S: When using a kM phosphor
Also contains the tetravalent metal element in the yttrium oxysulfide-based phosphor.
Abundance (k) and the resulting luminescent composition under slow electron beam excitation
A similar correlation to that of Fig. 1 was observed between
It was

Furthermore, the yttrium oxysulfide-based phosphor using Sm as the activator (Ln) is the composition of the phosphor and the resulting luminescent composition except that a luminescent composition showing reddish orange emission is obtained by adding Sm. A similar correlation was observed between the emission luminance characteristics of No. 1 and the emission luminance characteristics of No. 1 as in the case of the light emitting composition using Eu as the activator (Ln). Since the luminescent composition of the present invention emits light with sufficiently high brightness even under excitation by an electron beam with an accelerating voltage of several hundred V to several kV, it can be used for field emission displays in addition to the fluorescent film for fluorescent display tubes. It can also be used as a fluorescent film. Further, under electron beam excitation with an acceleration voltage of several kV, high-luminance light emission is exhibited without mixing or attaching a conductive substance.

[0022]

【Example】

(Example _{1~7) Y 2 O 3 216. 0} g La 2 O 3 6. 52g Eu 2 O 3 8. 10g SnO 2 0. 301g S 101 g Na 2 CO 3 70. 4 g K 3 PO 4 11 .0 g The above raw materials were thoroughly mixed and packed in an alumina crucible to give 110
After calcining at 0 ° C. for 1 hour, the obtained calcined product was washed with water, filtered, dried at 120 ° C. for 16 hours, sieved to make the particle diameter uniform, and the composition formula (Y _0.957 , La _0.02 , Eu) was used.
_A yttrium-lanthanum oxysulfide phosphor (phosphor [1]) represented by _0.023 ) ₂ O ₂ S: (0.002) Sn was obtained.

Next, 82 g of this phosphor [1] and In₂O
₃18g and a ball mill were thoroughly mixed to form a light emitting assembly.
A product (luminescent composition [1]) was produced. Aside from this,
0.301g SnO₂Instead of 0.541
g of SiO₂, 0.418 g GeO₂, 0.239 g
PbO, 0.40g TiO ₂, 0.185 g Zr
O₂, Or 0.211 g of HfO₂Above, except that
Manufacture phosphors [2] to [7] in the same manner as phosphor [1]
I made it. Next, these six types of phosphors (phosphors [2] to
[7]) 82 g of In₂O₃With
-Six kinds of light-emitting compositions that are well mixed using rumil
(Light emitting compositions [2] to [7]) were produced.

Comparative Example 1 From the phosphor raw material of Example 1, S
A yttrium-lanthanum oxysulfide phosphor (phosphor [R1]) was obtained in the same manner as in Example 1 except that nO ₂ was omitted. Next, a luminescent composition [R1] was produced in the same manner as the luminescent composition [1] of Example 1 except that this phosphor [R1] was used instead of the phosphor [1]. Then, the light emitting compositions [1] to [7] and [R1] thus obtained were irradiated with a low-speed electron beam with an acceleration voltage of 60 V, and the emission brightness thereof was measured and shown in Table 1.

[0025]

[Table 1]

(Embodiment 8) In the first embodiment, the phosphor material is used.
8.10g Eu as a charge₂O₃Instead of 7.04g
Eu₂O₃And 1.05 g of Sm₂O₃To
A composition formula (Y_0.957,
La_0.020, Eu_0.02, Sm_0.003)₂O ₂S: (0.002)
Yttrium-lanthanum oxysulfide phosphor represented by Sn
(Phosphor [8]) was obtained. Next, instead of the phosphor [1]
In the same manner as in Example 1 except that this phosphor [8] is used.
A luminescent composition (luminescent composition [8]) was produced.

Comparative Example 2 A composition formula (Y _0.957 , La _0.020 , Eu _0.02 , Sm _0.003 ) was obtained in the same manner as in Example 8 except that SnO ₂ as a phosphor raw material was omitted.
_A yttrium-lanthanum oxysulfide phosphor (phosphor [R2]) represented by ₂ O ₂ S was obtained. Next, a light emitting composition (light emitting composition [R2]) was produced in the same manner as in Example 8 except that this phosphor [R2] was used instead of the phosphor [8].

(Evaluation) The light emitting composition [8] and the light emitting composition [R2] were each irradiated with a low-speed electron beam with an acceleration voltage of 60 V, and the light emitting brightness was compared. Was 1.40 times that of the light emitting composition [R2].

Example 9 In Example 1, 8.08 g of Eu ₂ O ₃ was used instead of 8.10 g of Eu ₂ O ₃ as the phosphor raw material, and 0.0183 g of Tb ₂ O ₃ was further used. The composition formula (Y _0.957 ,
La _0.020 , Eu _0.02295 , Tb _0.00005 ) ₂ O ₂ S:
A yttrium-lanthanum oxysulfide phosphor (phosphor [9]) represented by (0.002) Sn was obtained. Next, a luminescent composition (luminescent composition [9]) was produced in the same manner as in Example 1 by using this phosphor [9] in place of the phosphor [1].

(Comparative Example 3) A composition formula (Y _0.957 , La _0.020 , Eu _0.02995 , Tb) was obtained in the same manner as in Example 9 except that SnO ₂ as a phosphor raw material was omitted.
_0.00005 ) Yttrium-lanthanum oxysulfide phosphor (phosphor [R3]) represented by ₂ O ₂ S was obtained. Next, a light emitting composition (light emitting composition [R3]) was produced in the same manner as in Example 9 by using this phosphor [R3] instead of the phosphor [9].

(Evaluation) The above-mentioned luminescent composition [9] and luminescent composition [R3] were each irradiated with a low-speed electron beam with an accelerating voltage of 60 V to compare the luminescent brightness. Was 1.35 times that of the light emitting composition [R3].

[0032]

According to the present invention, by adopting the above constitution, in a light emitting composition comprising a yttrium oxysulfide phosphor containing a specific amount of a tetravalent metal and a conductive material, an accelerating voltage of several kV or less, In particular, it is possible to provide a light-emitting composition that exhibits high-luminance red emission under excitation of a low-speed electron beam of several hundreds V or less and is suitable for a fluorescent film of a fluorescent display tube, a field emission display, and other fluorescent films for electronic displays. It became so.

[Brief description of drawings]

FIG. 1 is a component of a luminescent composition of the present invention (Y
₉ is a graph showing the relationship between the content (k) of Sn in a _0.957 , La _0.02 , Eu _0.023 ) ₂ O ₂ S: kSn phosphor and the relative emission brightness of the light emitting composition.

Claims (5)

[Claims] 1. A rare earth oxysulfide phosphor light-emitting composition obtained by mixing or adhering a conductive substance to an yttrium oxysulfide-based phosphor represented by the following composition formula. _{(Y 1-xy, La x} , Ln y) 2 O 2 S: kM ( where, Ln is Eu and / or Sm, M is Si, Ge,
At least one of Sn, Pb, Ti, Zr, and Hf, and x, y, and k are 0.001 ≦ x ≦ 0.
035, 0.001 ≦ y ≦ 0.20, and 0 <k ≦
It is a number that satisfies 0.5) 2. A rare earth oxysulfide phosphor luminescent composition obtained by mixing or adhering a conductive substance to the yttrium oxysulfide phosphor represented by the following composition formula. (Y _1-xyz, La _x, Lny _, Tb _z ) ₂ O ₂ S: kM (where Ln is Eu and / or Sm, M is Si, Ge,
At least one of Sn, Pb, Ti, Zr, and Hf, and x, y, z, and k are each 0.001 ≦ x ≦
0.035, 0.001 ≤ y ≤ 0.20, 10 ^-6 ≤ z ≤
It is a number that satisfies the condition of 10 ^-4 and 0 <k ≦ 0.5) 3. The k value is 5 × 10 ⁻⁶ ≦ k ≦ 5 × 10 ⁻²
The rare earth oxysulfide phosphor light-emitting composition according to claim 1 or 2, characterized in that 4. The mixture of the conductive material and the yttrium oxysulfide phosphor in an amount of 5 to 30% by weight based on the total amount of the rare earth oxysulfide phosphor light emitting composition.
2. The rare earth oxysulfide phosphor luminescent composition according to any one of 1 to 3. 5. The method according to claim 1, wherein 1 to 25% by weight of the conductive material is adhered to the surface of the yttrium oxysulfide-based phosphor with respect to the total amount of the rare earth oxysulfide phosphor light-emitting composition. 4. The rare earth oxysulfide phosphor light-emitting composition according to any one of 3 above.