JP3185752B2 - Phosphor material, phosphor film and plasma display panel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phosphor material and a phosphor film which emit light with high efficiency and long life, and a rare gas discharge light emission used for a color television receiver or display for displaying characters or images. The present invention relates to a plasma display panel used.

[0002]

2. Description of the Related Art A conventional plasma display panel will be described below. FIG. 7 is a cross-sectional view schematically showing an alternating current (AC) type plasma display panel.

In FIG. 7, reference numeral 41 denotes a front cover plate (front glass substrate).
The display electrode 42 is formed on 1. Further, the front cover plate 41 on which the display electrodes 42 are formed
Represents a dielectric glass layer 43 and magnesium oxide (Mg)
O) Covered by a dielectric protection layer 44.

Reference numeral 45 denotes a back glass substrate (back plate). On the back glass substrate 45, address electrodes 46, partition walls 47, and phosphor layers (50 to 52) are provided. It is a discharge space for filling gas. The phosphor layer is red 5 for color display.
Phosphor layers of three colors of 0, green 51, and blue 52 are arranged in order. Each of the above phosphor layers (50 to 52) is made of ultraviolet light having a short wavelength (147 nm, 172 nm) generated by discharge.
nm).

[0005]

In a conventional plasma display panel, a phosphor layer is formed by applying an ink containing phosphor particles by a printing method, or
It is produced by coating a sheet containing phosphor particles.

In either method, it is necessary to bake at about 500 ° C. after forming the phosphor layer in order to remove the organic binder component present in the ink or sheet.

Further, in order to bond the front cover plate and the back plate, a baking process at 400 ° C. or higher is required again.

[0008] In these firing processes, the phosphor used undergoes a certain degree of thermal change, causing a deterioration in luminance or chromaticity. In particular, Ba (1-x) MgAl ₁₀ O ₁₇ : Eux, which is currently used as a blue phosphor, is significantly deteriorated by heat.

Further, Ba (1-x) MgAl ₁₀ O ₁₇ : Eux used as the blue phosphor is damaged by vacuum ultraviolet rays (wavelengths of 147 nm and 172 nm) which are short wavelength excitation light of the plasma display panel. The light emission intensity decreases with the panel lighting time, and there is a problem in terms of life.

[0010] As described above, the blue phosphor of the plasma display panel has a problem that the phosphor material is deteriorated by heat and has a short life in a firing process required for its manufacture.

It is an object of the present invention to provide a plasma display panel having a relatively high luminance and a long life by forming a phosphor film having good emission characteristics by improving the phosphor material. .

[0012]

Means for Solving the Problems To achieve the above object, the phosphor material of the present invention has a composition of Ba (1-xy) Sry.
In the phosphor material represented by MgaAlbOc: Eux, x is 0.08 or less and 0.01 or more.

A conventional blue phosphor, Ba (1-x) Mg
In a phosphor material such as Al ₁₀ O ₁₇ : Eux, E
The substitution amount of u2 ⁺ ions is such that x is 0.1 to 0.15.

This is because the initial luminance increases as the amount of Eu ²⁺ ion substitution increases, but the heat resistance tends to improve as the Eu ²⁺ ion substitution amount decreases.
After the firing process at around 00 ° C., x is 0.1 to 0.1.
This is because the brightness of the film becomes the highest around 5.

On the other hand, from the viewpoint of the image quality of the panel, the evaluation of the chromaticity as well as the luminance is important, and the evaluation of the emission intensity (the value obtained by dividing the luminance by the y value of the chromaticity) having these as parameters is important. Becomes

Comparing the light emission intensities, after firing at about 500 ° C., the value of x is approximately equal to or less than 0.1.

In the plasma display panel,
In order to bond the front and back panels, baking at about 400 ° C. is necessary. Despite this temperature being lower than the baking temperature of the phosphor at about 500 ° C., the emission intensity is deteriorated. Therefore, by increasing the heat resistance by setting the substitution amount of Eu ²⁺ ions as in the configuration of the present invention, it becomes possible to realize a phosphor film having higher emission intensity than a conventional phosphor film.

In the above configuration, x is preferably 0.075 or less and 0.02 or more.

Further, x is preferably 0.06 or less and 0.03 or more. Moreover, y is 0.2 or less, 0.0
It is preferably one or more.

Ba (1-x) MgAl_TenO₁₇: Life of Eux
Life (UV resistance) is generally Eu ²⁺The amount of ion replacement
It tends to become longer as the number increases. But as mentioned above
There is a trade-off relationship with heat resistance. Ba (1-x) Mg
Al_TenO₁₇: Life of Eux is replaced by part of Ba with Sr
Can improve it. Therefore Eu²⁺I
The on-substitution amount is reduced as in the configuration of the present invention,
By changing the amount of Sr to be replaced as in the configuration of the present invention,
Longer life phosphor with higher heat resistance than conventional phosphor
Can be realized.

In the above configuration, y is 0.2 or less,
It is preferably 0.01 or more. Furthermore, if y is 0.
It is preferably 15 or less and 0.02 or more.

Further, it is preferable that y is 0.1 or less and 0.02 or more. Furthermore, x + y is 0.2 or less,
It is preferably 0.05 or more.

Further, x + y is 0.15 or less, 0.09
It is preferable that it is above. Further, a phosphor film of the present invention is characterized by being composed of the above phosphor material. Further, in the plasma display panel of the present invention, the electrodes and the phosphor layers of a plurality of colors are arranged between a pair of parallelly arranged plates, and a discharge space in which a gas medium is sealed is formed. A plasma display panel which emits ultraviolet light and emits light by converting it into visible light with the phosphor layer, wherein at least one phosphor layer of the phosphor layer is constituted by the phosphor film. Features.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment) Hereinafter, a plasma display panel according to an embodiment of the present invention will be described. FIG. 6 is a sectional view schematically showing an AC surface discharge type plasma display panel according to the present embodiment. Although only one cell is shown in FIG. 6, a PDP is formed by arranging a large number of cells that emit red, green, and blue light.

This PDP has address electrodes on a front glass substrate (front cover plate) 11 on which display electrodes 12, a dielectric glass layer 13 and a protective layer 14 are arranged, and on a rear glass substrate (back plate) 15. Electrode 16,
A back panel on which the visible light reflecting layer 17, the partition wall 18, and the phosphor layer 19 are arranged is laminated, and a discharge gas is sealed in a discharge space formed between the front panel and the back panel. It is manufactured as shown in FIG.

(Fabrication of Front Panel) In the front panel, a display electrode 12 is formed on a front glass substrate 11, and the display electrode 12 is covered with a lead-based dielectric glass layer 13.
3 is formed by forming a protective layer 14 on the surface.

In the present embodiment, the display electrode 12 is a silver electrode, and is formed by a method in which a paste for a silver electrode is screen-printed and then fired. Further, the composition of the dielectric glass layer 13 of the lead-based, lead oxide [PbO] 70 _{wt%, [2 O 3 B]} 15 % by weight boron oxide, a silicon oxide [SiO _2] 15% by weight, screen printing About 20
It was formed to a thickness of μm.

Next, CVD is performed on the dielectric glass layer 13 described above.
A protective layer 14 of 1.0 μm magnesium oxide (MgO) was formed by a chemical vapor deposition method.

(Preparation of Back Panel) Back glass substrate 15
An address electrode 16 is formed thereon by screen printing a paste for a silver electrode and then firing, and a visible light reflecting layer 17 made of TiO ₂ particles and dielectric glass is formed thereon by screen printing and firing. The glass partition walls 18 obtained by repeating the screen printing and firing are formed at a predetermined pitch.

Then, in each space between the partition walls 18,
The phosphor layer 19 is formed by disposing one of a red phosphor, a green phosphor, and a blue phosphor. The method for forming the phosphor layer 19 and the phosphor material to be used will be described later in detail, but the phosphor ink is applied by a method of scanning while continuously ejecting the phosphor ink from the nozzle, and after the application, about 500 ° C. And fired in air.

In the present embodiment, the height of the partition wall is 0.1 in accordance with a 40-inch class high-definition television.
0.15 mm, and the partition wall pitch is 0.15 to 0.3 m
m. The phosphor layer 19 formed on the back cover surface and the side wall of the partition wall was composed of phosphor particles having an average particle size of 1 to 7 μm and had a thickness of 5 to 50 μm.

(Preparation of PDP by Panel Lamination)
Next, the front panel and the rear panel thus manufactured are bonded to each other using sealing glass so that the front panel, the display electrode, and the address electrode are orthogonal to each other. High vacuum (8 ×
The PDP is manufactured by evacuating to 10 ⁻⁷ Torr and filling a discharge gas having a predetermined composition at a predetermined pressure.

In the present embodiment, the content of Xe in the discharge gas is 5% by volume, and the filling pressure is 500 to 8%.
The range was set to 00 Torr.

FIG. 5 is a schematic structural view of an ink coating apparatus 20 used when forming the phosphor layer 19. As shown in FIG. 5, in the ink application device 20, a phosphor ink is stored in a server 21, and a pressurizing pump 22 pressurizes the ink and supplies the pressurized ink to a header 23. The header 23 has an ink chamber 23
a and a nozzle 24 are provided, and the ink that has been pressurized and supplied to the ink chamber 23 a is continuously ejected from the nozzle 24.

The phosphor ink is prepared by blending phosphor material particles of each color, a binder, a solvent component, and, if necessary, a surfactant, silica and the like so as to have an appropriate viscosity.

In addition, as a method for forming the phosphor layer, other methods such as a method of applying a phosphor ink by a screen printing method, a method of preparing a sheet containing a phosphor material and adhering the sheet are used. It can be formed.

(Regarding Phosphor Material) As the phosphor material constituting the phosphor ink, PDPs other than blue are generally used.
Used for the phosphor layer can be used. Specific examples thereof include “green phosphor”: Zn ₂ SiO ₄ : Mn or BaAl
₁₂ O ₁₉ : Mn “Red phosphor”: YBO ₃ : Eu or (YxGd1-
x) BO ₃ : Eu.

The blue phosphor has a composition of Ba (1-x-
y) SryMgaAlbOc: Eux was used.

In order to obtain a phosphor film having good emission characteristics, it is necessary to study the heat resistance of these phosphor materials to be used. Figures 1 (a) and 1 (b) show Ba0.95-xSr0.05M.
gAl _{1 0} O _17: Eux of the phosphor material and Ba1-xM
The relative luminous intensity before and after the firing process when x in gAl ₁₀ O ₁₇ : Eux is changed is shown. The relative emission intensity, Ba0.9MgAl ₁₀ O _17: the emission intensity before firing Eu0.1 was relatively compared as 100.

The solid line in FIG. 1 indicates the characteristics of each phosphor before firing,
The dashed line indicates the characteristics after firing the phosphor at 520 ° C. in air, and the dashed line indicates the characteristics after firing at 520 ° C.
The properties after firing at 0 ° C. are shown. Ba0.95-xSr0.05
MgAl ₁₀ O ₁₇ : Eux and Ba 1 -xMgAl ₁₀ O
₁₇ : Eux shows the same tendency, but in the emission intensity comparison, the emission intensity not containing Sr was increased by about 1 to 2%.

In the comparison of the emission intensities of the respective materials after firing, after baking at 520 ° C., the values were almost equal at x = 0.1 or less, and further after firing at 460 ° C.
It became highest around x = 0.03 to 0.06.

Thus, in the emission intensity evaluation, x = 0.
When the value is 08 or more, the emission intensity tends to decrease with firing. On the other hand, when x = 0.08 or less, the emission intensity may increase by firing. In the case where heating is repeated twice or more, the best characteristics were obtained near x = 0.03 to 0.06.

The reason for this is that when the amount of Eu is relatively large, Eu ²⁺ ions are easily oxidized during firing,
It is considered that the emission intensity is deteriorated.

On the other hand, when the Eu content is relatively small, the oxidation of Eu ²⁺ ions during firing is small, and the emission intensity is improved by removing impurities such as moisture by firing and improving the crystallinity. it is conceivable that.

When the heat resistance is improved as the Eu content is smaller,
The tendency is that Ba0.95-xSr0.05MgAl_TenO₁₇: E
ux, not limited to Ba (1-x-y) SryMg
Al _TenO₁₇: Same inclination in Eux irrespective of Sr amount y
When the light emission intensity before firing is considered, x = 0.
The best characteristics were obtained near 03 to 0.06.

Further, the phosphor whose composition using Eu ²⁺ ion as an activator is represented by Ba (1-xy) SryMgaAlbOc: Eux is Ba (1-xy) SryMgAl ₁₀ O ₁₇ : E
ux, but not limited to Ba (1-xy) SryMg
Similar results were obtained using Al ₁₄ O ₂₃ : Eux or the like.

On the other hand, the blue phosphor used for the plasma display panel has a problem in terms of life, and it is necessary to study the durability of the phosphor material used.

FIG. 2 shows that Ba1-xMgAl ₁₀ O ₁₇ : Eu
The durability when x is changed in the phosphor material x is shown. The vertical axis represents the light emission intensity after 5000 hours of lighting, with the light emission intensity at the beginning of panel lighting being 100, and the horizontal axis represents x.

The conventional blue phosphor Ba1-xMgAl ₁₀ O
₁₇ : In Eux, the durability increases as x increases.
This is considered to be because the Eu ion substituted with the Ba ion has a smaller ion radius than that of the Ba ion, so that as x increases, the bond distance between Eu and oxygen decreases and the bond energy increases.

However, Ba1-xMgAl ₁₀ O ₁₇ : Eu
In x, x dependence on durability has a trade-off relationship with x dependence on heat resistance, and x is 0.1 to 0.1.
About 5 had been used.

FIG. 3 shows Ba (0.95-y) SryMgAl ₁₀ O
₁₇ : Durability when y is changed in the phosphor material of Eu0.05. The vertical axis indicates the light emission intensity at the initial panel lighting time
The emission intensity after lighting for 5000 hours when the value is set to 0, and the horizontal axis is y. When the amount of Eu (x) is constant, the durability increases as y increases. This is because, as in the case of the Eu dependence, Sr substituted by Ba ions rather than Ba ions.
It is considered that the ion has a smaller ionic radius, so that as y increases, the bond distance between Eu and oxygen decreases and the bond energy increases.

FIG. 4 shows Ba0.95-ySryMgAl.
The y-dependence of the relative emission intensity is shown after the phosphor material of ₁₀ O ₁₇ : Eu0.05 is fired at 460 ° C. in air after firing at 520 ° C. The relative luminescence intensity is y = 0 (Ba 0.95M
gAl ₁₀ O ₁₇ : Eu0.05) before sintering.
As a relative comparison. It can be seen that the emission intensity decreases with an increase in Sr, but only decreases by about 8% when y is up to 0.2 compared to a phosphor not containing Sr.

As described above, the conventional blue phosphor B
a1-xMgAl ₁₀ O _17: In EuX, there is a problem that durability Reducing the x in order to increase the heat resistance is deteriorated, had been used from these balance with x = 0.1 to 0.15, As in the present embodiment, in the phosphor represented by Ba (1-xy) SryMgAl ₁₀ O ₁₇ : Eux containing Sr, the Eu content x is set to 0.08 to 0.01, and the Sr content is further increased. By setting y to 0.2 to 0.01 or less, a phosphor material having improved heat resistance and durability over conventional phosphors can be obtained.

The heat resistance is further improved when x is 0.075 or less and 0.02 or more, and the best is obtained when x is 0.06 or less and 0.03 or more. In addition, the overall effect of heat resistance and durability is further improved when y is 0.15 or less and 0.02 or more, and is most favorable when y is 0.1 or less and 0.02 or more.

Since each of x and y affects heat resistance and durability, when these effects are considered, it is desirable that x + y is 0.2 or less and 0.05 or more. .15 or less and 0.09 or more were optimal values.

Each color phosphor used in the present embodiment can be manufactured as follows. The blue phosphor is first of all barium carbonate (BaCO ₃ ), magnesium carbonate (MgCO ₃ ),
Aluminum oxide _{(α-Al 2 O 3)} , strontium carbonate (SrCO _3), mixed europium oxide (Eu ₂ 0 ₃₎ by a predetermined amount. Then, an appropriate amount of flux (Al
F ₂ , BaCl ₂ ) with a ball mill,
° C. to 1650 ° C. at a predetermined time (e.g., 0.5 hours), obtained by sintering in a weak reducing atmosphere (H ^2, N ^2).

The red phosphor is composed of yttrium hydroxide Y ₂ (OH) ₃ , boric acid (H ₃ BO ₃ ), and a Y / B atomic ratio of 1 as raw materials.
Mix to make one. Next, a predetermined amount of europium oxide (Eu ₂ O ₃ ) was added to the mixture, and the mixture was mixed with a proper amount of flux by a ball mill.
It is obtained by firing at 0 ° C. to 1450 ° C. for a predetermined time (for example, 1 hour).

The green phosphor is made of zinc oxide (Zn) as a raw material.
O), silicon oxide (Si0 ₂₎ Zn, atomic ratio of 2 pairs of Si 1
It is blended so that it becomes. Next, a predetermined amount of manganese oxide (Mn ₂ O ₃ ) was added to this mixture, and after mixing with a ball mill,
At a temperature of 1200 ° C. to 1350 ° C. in air for a predetermined time (for example, 0.
5 hours) obtained by firing.

(Example)

[0060]

[Table 1]

The panel No. PDPs Nos. 1 to 4 are PDPs according to the examples manufactured based on the above embodiment, and are blue phosphor Ba (1-xy) SryMgAl ₁₀ O ₁₇ : E
x and y in ux are changed. Note that the panel No. PDPs 5 and 6 are PDPs according to comparative examples.

In each of the above-mentioned PDPs, the firing after forming the phosphor film was 520 ° C., and the firing when bonding the panels was 4 ° C.
Performed at 60 ° C. The thickness of the phosphor was set at 20 μm, and the discharge gas pressure was set at 500 Torr. The panel luminance of each PDP was measured under a discharge condition of a discharge sustaining voltage of 150 V and a frequency of 30 kHz.

Note that the luminance in the table is the luminance when the signals of the respective colors are adjusted to make the color temperature of white display 9500 degrees.

According to the evaluation result of the panel, the initial luminance is influenced by x and y, and x = 0.05, and the luminance becomes higher as the panel becomes smaller in y. Further, in the luminance after panel lighting for 5000 hours, the durability is improved as the value of x + y is increased. These results show that, in particular, x = 0.05 and y =
The improvement in luminance in the panel of 0.05 (No. 2) was large.

[0065]

As described above, when the phosphor material of the present invention is used, a phosphor film having high heat resistance and high durability is formed.
Thermal degradation and emission intensity degradation during lighting in the firing process during plasma display panel production are suppressed, and a plasma display panel with high emission intensity, long life, and good image quality can be realized.

[Brief description of the drawings]

FIGS. 1A and 1B are diagrams showing heat resistance of a phosphor material according to an embodiment of the present invention.

FIG. 2 is a diagram showing durability of a conventional phosphor.

FIG. 3 is a diagram showing durability of a phosphor material according to an embodiment of the present invention.

FIG. 4 is a view showing heat resistance of a phosphor material according to one embodiment of the present invention.

FIG. 5 is a schematic configuration diagram of an ink coating apparatus used when forming a phosphor layer in the present embodiment.

FIG. 6 is a sectional view schematically showing an AC surface discharge type plasma display panel according to one embodiment of the present invention.

FIG. 7 is a schematic sectional view of a conventional AC surface discharge type plasma display panel.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Front glass substrate (front cover plate) 12 Display electrode 13 Dielectric glass layer 14 Dielectric protection layer (MgO) 15 Back glass substrate (back plate) 16 Address electrode 17 Visible light reflection layer 18 Partition wall 19 Phosphor layer

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-56-86982 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C09K 11/08-11/89 H01J 9 / 22-9/227 H01J 11/02

Claims (21)

(57) [Claims] An electrode is provided between a pair of parallel plates.
And multiple color phosphor layers and seal the gas medium
Plasma display with a discharge space formed
A fluorescent panel of at least one color of the phosphor layer.
The optical layer has a composition of Ba (1-xy) SryMgaAlbO.
c: expressed by Eux (a = 1, b = 10, c = 17)
In the phosphor material, x is 0.08 or less, 0.01 or more
Wherein y is 0.2 or less and 0.01 or more
Display panel composed of materials. 2. An electrode between a pair of parallel plates.
And multiple color phosphor layers and seal the gas medium
Plasma display with a discharge space formed
A fluorescent panel of at least one color of the phosphor layer.
The optical layer has a composition of Ba (1-xy) SryMgaAlbO.
c: expressed by Eux (a = 1, b = 14, c = 23)
In the phosphor material, x is 0.08 or less, 0.01 or more
Wherein y is 0.2 or less and 0.01 or more
Display panel composed of materials. 3. The plasma display panel according to claim 1, wherein the pair of parallel plates are sealed with glass. 4. x is 0.075 or less and 0.02 or more.
The plasma display according to claim 1.
Play panel. 5. A contract wherein x is 0.06 or less and 0.03 or more.
The plasma display according to any one of claims 1 to 3.
Ray panel. 6. A contract wherein y is 0.15 or less and 0.02 or more.
The plasma display according to any one of claims 1 to 5.
Ray panel. 7. The method according to claim 1, wherein y is 0.1 or less and 0.02 or more.
The plasma display according to any one of claims 1 to 5.
Ipanel. 8. x + y is not more than 0.2 and not less than 0.05.
A plasma display according to any one of claims 1 to 7.
Play panel. 9. x + y is not more than 0.15 and not less than 0.09.
The plasma display according to any one of claims 1 to 7,
Spray panel. 10. An electrode and phosphor layers of a plurality of colors on a back panel.
Arrange the front panel and the back panel
A plasma display that forms a discharge space by enclosing a gas medium
A method for manufacturing a play panel, wherein the phosphor material is fired.
After forming, the phosphor material is further heated, and the phosphor layer is heated.
At least one color phosphor layer having a composition of Ba (1-x-y) S
ryMgaAlbOc: Eux (a = 1, b = 10, c
= 17), x is 0.08
Below, 0.01 or more, y is 0.2 or less, 0.01
A process formed by firing the above phosphor material
A method for manufacturing a plasma display panel. 11. A back panel having electrodes and phosphor layers of a plurality of colors.
Arrange the front panel and the back panel
A plasma display that forms a discharge space by enclosing a gas medium
A method for manufacturing a play panel, wherein the phosphor material is fired.
After forming, the phosphor material is further heated, and the phosphor layer is heated.
At least one color phosphor layer having a composition of Ba (1-x-y) S
ryMgaAlbOc: Eux (a = 1, b = 14, c
= 23), x is 0.08
Below, 0.01 or more, y is 0.2 or less, 0.01
A process formed by firing the above phosphor material
A method for manufacturing a plasma display panel. 12. x is not more than 0.075 and not less than 0.02.
A plasma display according to claim 10 or claim 11.
Panel manufacturing method. 13. x is 0.06 or less and 0.03 or more.
A plasma display panel according to claim 10 or claim 11.
Manufacturing method of flannel. 14. y is 0.15 or less and 0.02 or more.
A plasma display according to claim 10.
Manufacturing method of ray panel. 15. y is not more than 0.1 and not less than 0.02.
A program according to any one of claims 10 to 13, characterized in that:
A method for manufacturing a plasma display panel. 16. x + y is not more than 0.2 and not less than 0.05.
The plasma according to any one of claims 10 to 15,
Display panel manufacturing method. 17. When x + y is 0.15 or less and 0.09 or more,
The plasm according to any one of claims 10 to 15.
Manufacturing method of display panel. 18. The phosphor material is at least 400 ° C.
Claims after heating 10 to claim 17
Of manufacturing the above-described plasma display panel. 19. The method according to claim 19, wherein the phosphor material is at least 500 ° C.
The method according to any one of claims 10 to 17, which is subjected to the above heating.
Of manufacturing the above-described plasma display panel. 20. The heating temperature of the second heating is lower than the heating temperature of the first heating.
The method according to any one of claims 10 to 19,
A method for manufacturing a plasma display panel. 21. The phosphor layer is formed of at least phosphor material particles.
After applying the ink or sheet containing the ink to the substrate,
Claims formed by firing the phosphor material particles
The plasma display according to any one of claims 10 to 20.
Play panel manufacturing method.