KR100502892B1 - Phosphor paste composition for plasma display panel - Google Patents

Abstract

The present invention relates to a method for producing a spherical blue phosphor for a plasma display panel and a spherical blue phosphor for a plasma display panel manufactured therefrom, and more particularly, to a method for producing a blue phosphor for a plasma display panel, comprising a spherical aluminum-containing compound ; Barium-containing compounds; Magnesium-containing compounds; And a process for producing a spherical blue phosphor for a plasma display panel, wherein the europium-containing compound is fired under a reducing atmosphere, and a blue phosphor for a plasma display panel produced therefrom.

Since the spherical blue phosphor for a plasma display panel of the present invention widens the light emitting area and the discharge space in the panel, the plasma display including the fluorescent layer prepared by coating a phosphor paste composition containing the spherical blue phosphor and then baking the same is used for brightness and discharge. Excellent property

Description

Phosphor paste composition for plasma display panel {PHOSPHOR PASTE COMPOSITION FOR PLASMA DISPLAY PANEL}

[Industrial use]

The present invention relates to a method for producing a spherical blue phosphor for a plasma display panel and a spherical blue phosphor for a plasma display panel manufactured therefrom, and more particularly, to a method for producing a spherical blue phosphor for plasma display panel having excellent brightness and discharge characteristics. A spherical blue phosphor for plasma display panel produced therefrom.

[Prior art]

BACKGROUND OF THE INVENTION A plasma display panel is a display device for realizing an image by exciting phosphors by ultraviolet radiation formed from plasma, and a reflective AC driving plasma display panel is widely used.

The structure of the plasma display panel will be described with reference to FIG. 1.

In the upper panel, two parallel transparent electrodes 3 and an auxiliary electrode 5 are covered with a transparent dielectric layer 7 on the upper glass 1, and an MgO oxide film 9 is formed thereon.

In addition, a plurality of address electrodes 13 are formed on the bottom substrate 11 on the bottom panel 11, and a back dielectric layer 15 is formed on the front side of the address electrode 13 and the back substrate 11. 15, a plurality of partition walls 17 are formed to partition the discharge spaces in the form of lines corresponding to the respective address electrodes 13, and the fluorescent layer 19 is covered between the partition walls 17. In FIG.

The phosphor layer 19 is prepared by applying a phosphor paste, drying and baking. The plasma display panel is manufactured by assembling, encapsulating, exhausting, injecting gas, and aging the upper and lower panels.

The method of forming a fluorescent layer widely used at present is a screen printing method. However, the screen printing method has a problem in that the cell pitch is very narrow and a high quality TV level panel cannot be manufactured.

The fluorescent layer includes all of red, green, and blue phosphors. Among them, blue phosphors are solid solid materials, unlike red and green phosphors, and have a hexagonal structure. It cannot be formed. Therefore, there is a problem that can not display the brightness and discharge characteristics of the high-definition TV level.

In order to improve the above problem, Korean Patent Publication No. 2001-0031871 discloses a method of reducing the phosphor solid content and a method of reducing the particle size of the phosphor when the phosphor paste is prepared.

However, since the method is directly related to the luminescence brightness, it is difficult to control the solid content of the phosphor and the particle size of the phosphor, and there is a problem that the lifetime is shorter as the particle diameter of the phosphor is smaller.

In addition, since the blue phosphor is non-uniform in shape and generally has a plate shape, the discharge space varies greatly depending on the thickness or thickness of the fluorescent layer formed in the panel, and thus there is a problem in that the emission luminance is uneven and the discharge characteristics are deteriorated.

In addition, the fluorescent layer including only the plate-shaped phosphor has a large surface area and there is a problem in that deterioration due to ion impact, which is one of the most serious problems of blue phosphor, is reduced.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a method for producing a spherical blue phosphor for a plasma display panel having a wide light emitting area and a discharge space and excellent luminance and discharge characteristics.

Another object of the present invention is to provide a spherical blue phosphor for a plasma display panel manufactured by the above method.

Another object of the present invention is to provide a phosphor paste composition for a plasma display panel comprising a spherical blue phosphor.

In order to achieve the above object, the present invention provides a method for producing a blue phosphor for a plasma display panel, the spherical aluminum-containing compound; Barium-containing compounds; Magnesium-containing compounds; And a method for producing a spherical blue phosphor for a plasma display panel, wherein the europium-containing compound is calcined under a reducing atmosphere.

The present invention also provides a spherical blue phosphor for a plasma display panel manufactured by the above method.

The present invention also provides a phosphor paste composition comprising the spherical blue phosphor for the plasma display panel.

Hereinafter, the present invention will be described in more detail.

The present invention provides a method for producing a blue phosphor for a plasma display panel, comprising: a spherical aluminum-containing compound; Barium-containing compounds; Magnesium-containing compounds; And a method for producing a spherical blue phosphor for a plasma display panel, wherein the europium-containing compound is fired in a reducing atmosphere.

Phosphors for plasma display panels include (Y, Gd) BO ₃ : Eu (red phosphor), Zn _2-x Mn _x SiO ₄ : Y series: Ba series (where x is 0.1 to 0.5) (green phosphor) , BaMgAl ₁₀ O ₁₇ : Eu (blue phosphor) and the like are widely used.

Blue phosphors are solid solid materials, unlike red phosphors and green phosphors, and have a hexagonal structure. Therefore, the blue phosphors have a low filling density and thus cannot form a thin phosphor layer in a cell composed of narrow partitions.

2A and 2B are cross-sectional views of phosphor layers prepared by coating the phosphors of Example 1 and Comparative Example 1, respectively. Fig. 2A uses spherical blue phosphors, and Fig. 2B relates to using plate-like blue phosphors. Since the ultraviolet wavelength generated in the vacuum ultraviolet region is a short wavelength, as shown in FIG. 2A, ultraviolet rays entering between the particles of the spherical blue phosphor freely move into the surface of the fluorescent layer and the fluorescent layer and collide with many new light emitting materials, resulting in a vacuum. Ultraviolet rays excite the spherical blue phosphor, and thus the amount of visible light emitted is increased, thereby increasing the emission luminance of the panel.

In addition, since the spherical blue phosphor has excellent fluidity in the paste state, it is possible not only to increase the filling density of the fluorescent layer to a desired level, but also to form a fluorescent layer by firing a paste composition containing the spherical blue phosphor, thereby reducing the emission luminance. The thickness can be made thin and uniform.

Therefore, the fluorescent layer including the spherical blue phosphor can not only secure a sufficient discharge space, but also widen the surface area of the fluorescent layer, thereby improving panel emission luminance and improving discharge characteristics.

Conventionally, the plate-like blue phosphor generally used is an aluminum-containing compound which is a constituent of the mother, and a plate-shaped aluminum oxide is used. However, as described in the present invention, when a matrix is prepared using a spherical aluminum oxide, Since the shape maintains the shape of the spherical aluminum oxide used as a raw material, the shape becomes close to the spherical shape.

Therefore, as described above, the fluorescent layer prepared by firing the paste composition including the spherical blue phosphor has a short wavelength in the ultraviolet ultraviolet region, and thus, the ultraviolet ray between the particles of the spherical phosphor is formed on the surface of the fluorescent layer and It freely moves into the fluorescent layer and collides with many new light emitting materials. As a result, the vacuum ultraviolet rays excite the spherical phosphors, thereby increasing the amount of visible light emitted, thereby increasing the emission luminance of the panel.

The aluminum-containing compound, the barium-containing compound, the magnesium-containing compound, and the europium-containing compound, which are used as raw materials for producing the phosphor matrix, are aluminum oxide (Al ₂ O ₃ ), barium carbonate (Ba ₂ CO ₃ ), and magnesium, respectively. Oxides (MgO) and europium oxides (Eu ₂ O ₃ ) are preferred.

The phosphor prepared by calcining the aluminum oxide (Al ₂ O ₃ ), barium carbonate (Ba ₂ CO ₃ ), magnesium oxide (MgO) and europium oxide (Eu ₂ O ₃ ) under a reducing atmosphere is Ba _1-x MgAl _10. O ₁₇ : Eu _x (x = 0.01-0.15) is preferred, of which BaMgAl ₁₀ O ₁₇ : Eu is most preferred.

In the spherical blue phosphor manufacturing method for a plasma display panel of the present invention, the firing temperature is preferably 1400 to 1600 ° C. When the firing temperature is less than 1400 ℃, the crystallinity of the produced spherical blue phosphor is lowered, the brightness is lowered, the impurities content is increased, the color purity is lowered, and when the firing temperature exceeds 1600 ℃ of the produced spherical blue phosphor There is a problem that the crystallinity is too high and difficult to grind.

The present invention also provides a spherical blue phosphor for a plasma display panel manufactured by the above method.

A solvent and an organic binder resin are mixed with the spherical blue phosphor to prepare a phosphor paste composition for a plasma display panel. In addition, other additives such as an antifoaming agent and a dispersant may be further added to the paste composition.

The phosphor paste composition for a plasma display panel can be prepared by mixing a spherical blue phosphor and a plate-like blue phosphor that is commonly used. The mixing weight ratio of the spherical blue phosphor and the plate-shaped blue phosphor is preferably 50:50 to 99.9: 0.1. If the weight ratio of the spherical blue phosphor is smaller than the plate-shaped blue phosphor, the effect of improving the brightness and discharge characteristics of the plasma display panel is insignificant, which is not preferable.

As the organic solvent for preparing the paste composition, butyl carbitol acetate (BCA), terpineol (TP), toluene, texanol, butyl carbitol (BC), or a mixture thereof may be preferably used. Among them, a mixed organic solvent of butylcarbitol acetate (BCA) and terpineol (TP) may be preferably used.

The organic binder resin serves to increase the viscosity of the phosphor paste composition, and ethyl cellulose, nitro cellulose, acrylic resin, and the like may be preferably used.

       Dissolving an organic binder resin in an organic solvent to prepare a vehicle, adding phosphor powder to the vehicle, stirring and kneading the vehicle to which the phosphor is added, prepares a phosphor paste composition for a plasma display panel.

Then, the phosphor paste composition is coated between the prepared barrier ribs, dried, and calcined to form a fluorescent layer, and then the upper and lower panels are assembled, sealed, exhausted, gas injected, and aged to manufacture a plasma display panel. .

As described above in detail, since the spherical blue phosphor for plasma display panel of the present invention increases the light emitting area and the discharge space in the panel, the plasma display panel manufactured by firing the phosphor paste composition containing the spherical blue phosphor has the brightness and discharge characteristics. This is excellent.

Hereinafter, preferred examples and comparative examples of the present invention are described. The following examples and comparative examples are described for the purpose of more clearly expressing the present invention, but the contents of the present invention are not limited to the following examples and comparative examples.

Blue phosphor manufacturing

(Example 1)

Ba ₂ CO ₃ as a barium-containing compound, MgO as a magnesium-containing compound and spherical Al ₂ as an aluminum-containing compound by appropriate mass blending so that the molar ratio of Ba: Mg: Al: Eu is 1: 1: 10: 1 Eu ₂ O ₃ was weighed with O ₃ and europium-containing compounds and mixed by dry method. The prepared phosphor material was calcined in a mixed reducing gas atmosphere of 5% by volume of hydrogen and 95% by volume of nitrogen at 1500 ° C. for 4 hours to prepare a spherical blue phosphor (BaMgAl ₁₀ O ₁₇ : Eu).

(Comparative Example 1)

A plate-like blue phosphor was prepared in the same manner as in Example 1, except that plate-shaped alumina was used as the aluminum-containing compound.

Plasma display panel manufacturers

(Example 2)

A vehicle was prepared by dissolving 8 g of an organic binder resin of ethyl cellulose resin in a mixed organic solvent of 15 g of butylcarbitol acetate and 37 g of terpineol. Then, 40 g of the spherical blue phosphor prepared in Example 1 was added to the vehicle and stirred to prepare a paste. The paste was printed between the partition walls, the back surface was cleaned, and then fired to form a fluorescent layer. Then, the upper and lower panels of the panel were assembled, sealed, exhausted, gas injected, and aged to prepare a plasma display panel.

(Comparative Example 2)

The same process as in Example 2 was carried out except that the plate-like blue phosphor prepared in Comparative Example 1 was used.

For the plasma display panels manufactured in Example 2 and Comparative Example 2, the thickness of the fluorescent layer on the side, the thickness of the fluorescent layer on the bottom, the phosphor filling rate, the relative luminance, the external light reflectance luminance and the contrast of the panel were measured, and the results were as follows. Table 1 shows.

The phosphor filling rate was calculated by the following Equation 1.

In Equation 1, the weight of the phosphor in the film is obtained by multiplying the content of the weight of the phosphor by the weight of the phosphor to the weight of the phosphor paste composition excluding the organic solvent component per unit area, and d is the density of the phosphor (g / cm ³ ). Indicates.

Example 2 Comparative Example 2 Fluorescent layer Side thickness (μm) 34 51 Bottom thickness (㎛) 15 17 Phosphor Filling Rate (%) 45 35 Panel properties Relative luminance ¹⁾ (%) 117 100 External light reflection luminance (cd / ㎡) 12.3 13.1 Contrast ²⁾ (%) 122 100

Relative luminance and contrast of footnotes 1) and 2) are calculated as 100% of the luminance and contrast of the plasma display panel manufactured in Comparative Example 2.

As shown in Table 1, the fluorescent layer of the plasma display panel manufactured using the spherical blue phosphor of Example 2 compared to the fluorescent layer of the plasma display panel of Comparative Example 2 manufactured using the plate blue phosphor. It can be seen that the thickness of is more uniform.

In addition, the phosphor layer of the plasma display panel manufactured using the spherical phosphor of Example 1 was lower than the phosphor layer of the plasma display panel manufactured using the plate phosphor of Comparative Example 1 manufactured using the plate phosphor and the phosphor filling rate and luminance. The contrast is remarkably excellent.

In addition, the plasma display panel manufactured using the spherical phosphor of Example 1 has a lower external light reflectance than the plasma display panel manufactured using the plate-shaped phosphor of Comparative Example 1, which is similar to that of Example 2 manufactured using the spherical phosphor. Since more of the ultraviolet rays flowing into the fluorescent layer of the plasma display panel are not reflected but move to a narrow space in the fluorescent layer, the amount of ultraviolet rays reflected from the surface of the fluorescent layer is less. Accordingly, it can be seen that the amount of ultraviolet rays reflected from the surface of the fluorescent layer is small, so that the light emission luminance and discharge characteristics of the panel of Example 2 of the present invention are superior to the light emission luminance and discharge characteristics of the panel of Comparative Example 2.

Since the spherical blue phosphor for a plasma display panel of the present invention increases the light emitting area and the discharge space in the panel, a plasma display panel comprising a phosphor layer formed by stacking, drying and firing a phosphor paste composition containing the spherical blue phosphor between partition walls. Silver is excellent in brightness and discharge characteristics.

1 is a cross-sectional view of a plasma display panel.

2A and 2B are sectional views of the fluorescent layers of Example 1 and Comparative Example 1, respectively.

* Description of Major Symbols in Drawings *

1: top glass 3: transparent electrode

5: auxiliary electrode 7: transparent dielectric layer

9: MgO oxide film 11: back substrate

13 address electrode 15 backside dielectric layer

17: partition 19: fluorescent layer

Claims (6)

delete delete delete delete delete Spherical aluminum oxide; Barium-containing compounds; Magnesium-containing compounds; And a spherical blue phosphor prepared by calcining a europium-containing compound in a reducing atmosphere and a plate-shaped blue phosphor at a weight ratio of 50:50 to 99.9: 0.1.