JP2012233145A - Phosphor paste for plasma display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma display panel of a high quality, wherein mixed color is prevented from occurring and yield ratio is improved.SOLUTION: This invention relates to a phosphor paste of three primary colors, comprising a first phosphor, a second phosphor, and a third phosphor, wherein these phosphors contain the first, second and third organic solvents, respectively. The differences in interface tension between two organic solvents, selected from the first, second and third organic solvents, are each <2.0 mN/m.

Description

  The present invention relates to a plasma display panel used for image display such as a television receiver, and more particularly to a configuration of a phosphor paste for a plasma display panel having a phosphor layer that emits light when excited by ultraviolet rays.

  2. Description of the Related Art In recent years, plasma display panels (hereinafter referred to as “PDP”) devices in color display devices used for image display such as computers and televisions are large, thin, and lightweight. It is attracting attention as a device. The PDP device has a PDP that includes a front plate, a front plate, and a back plate disposed to face each other through a discharge space. In addition, the PDP apparatus performs full color display by additively mixing so-called three primary colors (red, green, and blue). In order to perform this full-color display, the PDP device is provided with phosphor layers that emit three primary colors of red (R), green (G), and blue (B), and the phosphors that constitute the phosphor layers. The body particles are excited by ultraviolet rays generated in the discharge cell of the PDP, and generate visible light of each color.

  Since the phosphor contained in the phosphor layer needs to be applied to the back plate of the PDP, various inorganic materials and organic binder resins are mixed as a phosphor material to form a paste, and then screen printing or from a nozzle It is applied by a discharging method or the like. And after apply | coating a fluorescent substance paste, it heat-fires to arbitrary temperature, it fixes to a backplate, and a desired fluorescent substance layer is formed (refer patent document 1).

JP-A-11-96911

  However, when applying the phosphor paste, a certain phosphor paste comes into contact with a different phosphor paste applied to an adjacent cell beyond a partition wall from a cell that should originally be entered. Then, a certain phosphor paste and a different phosphor paste are mixed in the cell (hereinafter referred to as mixed color).

  As a result, “color mixing failure” (hereinafter, referred to as color mixing failure) that greatly deteriorates the yield of PDP due to color mixing is caused.

  In order to solve this problem, the phosphor paste of the three primary colors of the present invention is the first primary phosphor paste composed of the first phosphor paste, the second phosphor paste, and the third phosphor paste. The difference in interfacial tension between two phosphor pastes selected from the phosphor paste, the second phosphor paste, and the third phosphor paste is 2.0 mN / m or less, respectively.

  According to the present invention, it is possible to suppress color mixing, improve yield, and provide a high-quality plasma display panel.

The perspective view which shows the principal part of the panel used for the PDP apparatus in one embodiment of this invention. The figure showing the electrode arrangement | sequence figure of PDP of the PDP apparatus in one embodiment of this invention The figure showing the cross section of PDP of the PDP apparatus in one embodiment of this invention

  Hereinafter, the PDP according to the first embodiment of the present invention will be described with reference to FIGS. However, the embodiment of the present invention is not limited to this.

<Embodiment 1>
1. Configuration of PDP FIG. 1 is an exploded perspective view showing a front panel 1 and a rear panel 2 separated from each other in the PDP according to the first embodiment of the present invention. FIG. It is sectional drawing which shows the discharge cell structure when it is set as PDP collectively. As shown in FIGS. 1 and 3, the PDP is configured by disposing a front plate 1 and a back plate 2 so as to form a discharge space 3 therebetween.

  The front plate 1 is a display electrode in which a scan electrode 5 as a conductive first electrode and a sustain electrode 6 as a second electrode are arranged in parallel to each other with a discharge gap between them on a glass front substrate 4. 7, a plurality of display electrodes 7 are arranged in the row direction, and a dielectric layer 8 made of a glass material is formed so as to cover the scan electrodes 5 and the sustain electrodes 6. The dielectric layer 8 A protective film 9 made of MgO is formed on the top. Scan electrode 5 and sustain electrode 6 are each made of a transparent electrode (not shown) such as ITO and a conductive metal such as silver (Ag) formed so as to be electrically connected to the transparent electrode. A bus electrode (not shown) having a thickness of about several μm is formed.

  The back plate 2 is provided with a plurality of data electrodes 12 made of silver (Ag) covered with an insulating layer 11 made of a glass material and arranged in a stripe shape in the column direction on a glass back substrate 10. On the insulator layer 11, a grid-like partition wall 13 made of a glass material for partitioning the discharge space 3 between the front plate 1 and the back plate 2 for each discharge cell is provided. Further, red (R), green (G), and blue (B) phosphor layers 14R, 14G, and 14B are provided on the surface of the insulator layer 11 and the side surfaces of the partition walls 13. The front plate 1 and the back plate 2 are arranged to face each other so that the scan electrode 5 and the sustain electrode 6 intersect the data electrode 12, and the scan electrode 5, the sustain electrode 6 and the data electrode 12 intersect each other. As shown in FIG. 2, a discharge cell 15 is provided. The discharge space 3 is filled with, for example, a mixed gas of neon and xenon as a discharge gas. Note that the structure of the PDP is not limited to that described above, and for example, a structure having stripe-shaped partition walls may be used.

  Here, as shown in FIG. 3, the cross-shaped barrier ribs 13 forming the discharge cells 15 include a vertical barrier rib 13b formed parallel to the data electrode 12, and a horizontal barrier rib formed so as to be orthogonal to the vertical barrier rib 13b. 13a. The phosphor layers 14R, 14G, and 14B formed by coating in the barrier ribs 13 are formed of stripes of blue phosphor layers 14B, red phosphor layers 14R, and green phosphor layers 14G along the vertical barrier ribs 13b. They are arranged in order.

  FIG. 2 is an electrode array diagram of the PDP shown in FIGS. N scanning electrodes Y1, Y2, Y3... Yn (5 in FIG. 1) and n sustaining electrodes X1, X2, X3... Xn (6 in FIG. 1) are arranged in a row. M data electrodes A1... Am (12 in FIG. 1) that are long in the direction are arranged. Discharge cells 15 are formed at portions where the pair of scan electrodes Y1 and sustain electrodes X1 and one data electrode A1 intersect, and m × n discharge cells 15 are formed in the discharge space. Further, as shown in FIG. 2, the scan electrode Y1 and the sustain electrode X1 are formed on the front plate 1 in a pattern that repeats in the arrangement of the scan electrode Y1, the sustain electrode X1, the sustain electrode X2, the scan electrode Y2,. Has been. Each of these electrodes is connected to a connection terminal provided at a peripheral end portion outside the image display area of the front plate 1 and the back plate 2.

2. PDP manufacturing method 2-1. Front plate manufacturing method Scan electrodes 5 and sustain electrodes 6 are formed on front substrate 4 by photolithography. The scanning electrode 5 is composed of a transparent electrode such as indium tin oxide (ITO) and a bus electrode made of silver (Ag) laminated on the transparent electrode. The sustain electrode 6 includes a transparent electrode such as ITO and a bus electrode made of Ag or the like laminated on the transparent electrode. As a material for the bus electrode, an electrode paste containing silver (Ag), a glass frit for binding silver, a photosensitive resin, a solvent, and the like is used. First, an electrode paste is applied to the front substrate 4 on which a transparent electrode is formed by a screen printing method. In addition to the method of screen printing the electrode paste, a sputtering method, a vapor deposition method, or the like can also be used. Next, the solvent in the electrode paste is removed by drying the electrode paste in a drying furnace. Next, the electrode paste is exposed through a photomask having a predetermined pattern. Next, the electrode paste is developed to form a bus electrode pattern. Finally, the bus electrode pattern is fired at a predetermined temperature in a firing furnace. That is, the photosensitive resin in the electrode pattern is removed. Further, the glass frit in the electrode pattern is melted. Thereafter, the glass frit that has been melted is vitrified by cooling the front plate to room temperature. A bus electrode is formed by the above process.

  Next, the dielectric layer 8 is formed. As a material for the dielectric layer 8, a dielectric paste containing a dielectric glass frit, a resin, a solvent, and the like is used. First, a dielectric paste is applied on the front substrate 4 by a die coating method so as to cover the scan electrodes 5 and the sustain electrodes 6 with a predetermined thickness. In addition to the method of die coating the dielectric paste, a screen printing method, a spin coating method, or the like can also be used. Alternatively, a film that becomes the dielectric layer 8 can be formed by a CVD (Chemical Vapor Deposition) method or the like without using the dielectric paste. Next, the protective layer 9 is formed on the dielectric layer 8. Next, the solvent in the dielectric paste is removed by drying the dielectric paste in a drying furnace. Finally, the dielectric paste is fired at a predetermined temperature in a firing furnace. That is, the resin in the dielectric paste is removed. At the same time, the dielectric glass frit melts. Thereafter, by cooling the front plate to room temperature, the molten dielectric glass frit is vitrified. Through the above steps, the dielectric layer 8 is formed.

  The front plate 1 having the scan electrode 5, the sustain electrode 6, the dielectric layer 8, and the protective layer 9 on the front substrate 3 is completed through the above steps.

2-2. Manufacturing Method of Back Plate Data electrodes 12 are formed on the back substrate 10 by photolithography. As a material of the data electrode 12, a data electrode paste containing silver (Ag) for ensuring conductivity, a glass frit for binding silver, a photosensitive resin, a solvent, and the like is used. First, the data electrode paste is applied on the back substrate 10 with a predetermined thickness by screen printing. In addition to the method of screen printing the data electrode paste, a sputtering method, a vapor deposition method, or the like can also be used.

  Next, the solvent in the data electrode paste is removed by a drying furnace. Next, the data electrode paste is exposed through a photomask having a predetermined pattern. Next, the data electrode paste is developed to form a data electrode pattern. Finally, the data electrode pattern is fired at a predetermined temperature in a firing furnace. That is, the photosensitive resin in the data electrode pattern is removed. At the same time, the glass frit in the data electrode pattern is melted. Thereafter, the glass frit that has been melted is vitrified by cooling to room temperature. The data electrode 12 is formed by the above process.

  Next, the insulator layer 11 is formed. As a material of the insulator layer 11, an insulator paste containing an insulator glass frit, a resin, a solvent, and the like is used. First, an insulating paste is applied by screen printing so as to cover the data electrode 12 on the back substrate 10 on which the data electrode 12 is formed with a predetermined thickness. In addition to the method of screen printing the insulator paste, a die coating method, a spin coating method, or the like can also be used. In addition, a film to be the insulator layer 11 can be formed by CVD (Chemical Vapor Deposition) method or the like without using the insulator paste.

  Next, the solvent in the insulator paste is removed by a drying furnace. Finally, the insulator paste is fired at a predetermined temperature in a firing furnace. That is, the resin in the insulator paste is removed. Moreover, the insulator glass frit is melted. Thereafter, by cooling to room temperature, the molten insulator glass frit is vitrified. The insulator layer 11 is formed by the above process.

  Next, the partition wall 13 is formed by photolithography. As a material of the partition wall 13, a partition wall paste including a filler, a glass frit for binding the filler, a photosensitive resin, a solvent, and the like is used. First, the barrier rib paste is applied on the insulator layer 11 with a predetermined thickness by a die coating method or the like. Next, the solvent in the partition wall paste is removed by a drying furnace. Next, the barrier rib paste is exposed through a photomask having a predetermined pattern. Next, the barrier rib paste is developed to form a barrier rib pattern. Finally, the partition pattern is fired at a predetermined temperature in a firing furnace. That is, the photosensitive resin in the partition pattern is removed. Further, the glass frit in the partition wall pattern is melted. Thereafter, the glass frit that has been melted is vitrified by cooling to room temperature. The partition wall 13 is formed by the above process. Here, in addition to the photolithography method, a sandblast method or the like can be used.

  Next, the phosphor layer 14 is formed. As a material for the phosphor layer 14, a phosphor paste containing phosphor particles, a binder, a solvent, and the like is used. First, the phosphor paste is applied on the insulating layer 11 between the adjacent barrier ribs 13 and on the side surfaces of the barrier ribs 13 with a predetermined thickness by a dispensing method. Next, the solvent in the phosphor paste is removed by a drying furnace. Finally, the phosphor paste is fired at a predetermined temperature in a firing furnace. That is, the resin in the phosphor paste is removed. The phosphor layer 14 is formed by the above steps. Here, in addition to the dispensing method, a screen printing method or the like can be used.

  Through the above steps, the back plate 2 having the data electrode 12, the insulator layer 11, the partition wall 13, and the phosphor layer 14 on the back substrate 10 is completed.

2-3. Assembly Method of Front Plate and Back Plate First, a sealing paste is applied around the back plate 2 by a dispensing method. The sealing paste may include beads, a low-melting glass material, a binder, a solvent, and the like. The applied sealing paste forms a sealing paste layer. Next, the solvent in the sealing paste layer is removed by a drying furnace. Thereafter, the sealing paste layer is temporarily fired at a temperature of about 350 ° C. The resin component etc. in the sealing paste layer are removed by temporary baking. Next, the front plate 1 and the back plate 2 are arranged to face each other so that the display electrode 7 and the data electrode 12 are orthogonal to each other.

  Further, the peripheral portions of the front plate 1 and the back plate 2 are held in a state of being pressed by a clip or the like. By firing at a predetermined temperature in this state, the low-melting glass material of the sealing paste is melted. Then, the low-melting-point glass material that has been melted is vitrified by cooling to room temperature. Thereby, the front plate 1 and the back plate 2 are hermetically sealed. Finally, a discharge gas containing Ne, Xe, etc. is sealed in the discharge space. The composition of the discharge gas to be sealed is the Ne-Xe system conventionally used, but the Xe content is set to 5% by volume or more, and the sealing pressure is set to a range of 55 kPa to 80 kPa. This completes the PDP.

3. Phosphor paste Next, the phosphor paste according to the present embodiment will be described. The following examples are provided for purposes of illustration and are not intended to limit the invention.

  The three primary color phosphor pastes of the present invention are the first primary phosphor paste, the second phosphor paste, and the three primary color phosphor paste constituted by the third phosphor paste. The difference in interfacial tension between the two phosphor pastes selected from the phosphor paste and the third phosphor paste is 2.0 mN / m or less, respectively. Each phosphor paste includes an organic binder resin, an organic solvent, and phosphor powder.

3-1. Organic Binder Resin First, the phosphor powder that is a constituent component of the phosphor paste in the present embodiment will be described. The organic binder resin that is a constituent component of the phosphor paste in the present embodiment is a cellulose ether binder resin such as methyl cellulose, ethyl cellulose, hydroxypropyl methyl cellulose, or a single amount of methyl methacrylate, methyl acrylate, ethyl acrylate, ethyl methacrylate, or the like. An acrylic binder resin obtained by polymerizing at least one selected from the body is used. The weight ratio (wt%) of the organic binder resin is preferably 3 wt% or more and 30 wt% or less with respect to the total weight of the phosphor paste containing at least the phosphor powder, the organic binder resin, and the organic solvent. When the weight ratio (wt%) of the organic binder resin is less than 3 wt%, the phosphor paste has a low viscosity, which is not suitable for application. In addition, when the weight ratio (wt%) of the organic binder resin exceeds 30 wt%, the phosphor powder density in the phosphor paste after firing becomes low, which may affect the brightness and the like.

3-2, Phosphor Powder Next, the phosphor powder that is a constituent component of the phosphor paste in the present embodiment will be described. The phosphor powder that is a constituent component of the phosphor paste in the present embodiment is preferably a phosphor that can efficiently emit light under vacuum ultraviolet light excitation with a wavelength of 200 nm or less, for example, 147 nm. Among them, (Y, Eu) (P, V) O ₄ or (Y, Gd, Eu) ₂ O ₃ or (Y, Gd, Eu) BO ₃ as red phosphor, (Zn) as green phosphor, , Mn) ₂ SiO ₄ or (Y, Tb) BO ₃ or (Y, Ce) ₃ (Al, Ga) ₅ O ₁₂ , (Ba, Eu) MgAl ₁₄ O ₂₄ or (Ba, Eu) MgAl as a blue phosphor _{When 10} O ₁₇ is used, it is particularly preferable because both the luminous efficiency and the hue are good. However, the phosphor paste is good as long as it contains at least one of the phosphors described above for each color, and is not limited to the phosphor powder for each color described above.

  The weight ratio (wt%) of the phosphor powder is preferably 20 wt% or more and 80 wt% or less with respect to the total weight of the phosphor paste containing at least the phosphor powder, the organic binder resin, and the organic solvent. When the weight ratio (wt%) of the phosphor powder is less than 20 wt%, the viscosity of the phosphor paste is lowered, the applicability is deteriorated, and the brightness as the PDP cannot be maintained. And when it exceeds 80 wt%, solubility with binder resin or an organic solvent worsens, and applicability | paintability worsens.

3-3. Organic Solvent Further, an organic solvent that is a constituent component of the phosphor paste of the present invention will be described. The organic solvent that is a constituent of the phosphor paste of the present invention is not particularly limited as long as the organic binder resin, the phosphor powder component, and the organic solvent are not separated from each other, and alcohol-based, ether-based, ester-based, glycol The system type is preferred. For example, terpineol, benzyl alcohol, γ-BL, tetralin, BCA, ethyl acetate, N-methylpyrrolidone, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol dimethyl ether, propylene glycol, ethylene glycol monoethyl ether acetate, 3- Methoxybutyl acetate, sol-fit, dipropylene glycol dimethyl ether, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, 1,8-cineol, dihydroterpineol, diethylene glycol monobutyl ether, tripropylene glycol monomethyl ether, diethylene glycol, dihydroterpinyl acetate , Eta , 2-phenoxyethanol, dipropylene glycol, 1,3-butylene glycol, glycerin, hexylene glycol, dimethylene glycol monomethyl ether, ethyl glycol, butyl glycol, diethylene glycol mono 2-ethylhexyl ether, ethylene glycol mono 2-ethylhexyl ether , Ethylene glycol monomethyl ether acetate, 3-methoxy-1-butanol, methoxybutyl acetate, isoprene glycol, isobornylcyclohexanol and the like are preferable because of excellent workability.

  Moreover, the organic solvent can be used alone or in plural. The weight ratio (wt%) of the organic solvent is preferably 10 wt% or more and 80 wt% or less of the total weight of the phosphor paste containing at least the phosphor powder, the organic binder resin, and the organic solvent. When the weight ratio (wt%) of the organic solvent is less than 10 wt%, the viscosity of the phosphor paste is increased, the solubility with the phosphor powder and the binder resin is also deteriorated, and the applicability is deteriorated. And even when it exceeds 80 wt%, the viscosity of the phosphor paste is lowered, and the applicability is deteriorated.

3-4, Method for Producing Phosphor Paste Next, a method for producing a phosphor paste containing the phosphor powder, the organic binder resin, and the organic solvent in the present invention will be described. The phosphor paste in the present invention is produced by the following method. First, the organic binder resin and the organic solvent described above are kneaded to prepare a polymer solution.

  Any of the phosphor powders described above is mixed in the polymer solution thus prepared, and preliminary kneading is performed for 30 to 50 minutes. Thereafter, as the main kneading, since the phosphor powder is sufficiently dispersed, the premixed polymer solution and the phosphor powder mixed solution are passed twice through three rollers. Thus, the phosphor paste is produced.

4. Example 4-1 Composition of phosphor paste Examples of the present invention will be described below. However, the present invention is not limited to this.

4-1-1, Details of Phosphor Paste <Example 1>
As Example 1, a red phosphor, an organic solvent, and an organic binder resin described below are mixed at a weight percent by weight, and a phosphor paste is prepared.
Red phosphor: (Y, Eu) (P, V) O ₄ ... 52 wt%
Organic binder resin: ethyl cellulose ... 9wt%
Organic solvent: terpineol ... 3.9 wt%, diethylene glycol monobutyl ether ... 15.6 wt%, N-methylpyrrolidone ... 19.5 wt%
Ethylcellulose is dissolved in terpineol, N-methylpyrrolidone and propylene glycol to prepare a polymer solution. A red phosphor (Y, Eu) (P, V) O ₄ is added to the polymer solution, and preliminary kneading is performed for 50 minutes. Thereafter, the phosphor paste of Example 1 is obtained by passing it through three rollers twice. The resulting phosphor paste of Example 1 has a viscosity of 60000 Pa · s (at room temperature of 25 degrees).

  The interfacial tension of the organic solvent was measured by a pendant drop method (Nick Corporation: contact angle meter LSE-A100T).

  The interfacial tension in the organic solvent in the phosphor paste of Example 1 is 33 mN / m. Similar to the organic solvent, the phosphor paste is measured by the pendant drop method (Nick Corporation: contact angle meter LSE-A100T). At this time, the interfacial tension of the phosphor paste of Example 1 is 26 mN / m, and the interfacial tension value of the phosphor paste is smaller than the interfacial tension value of the organic solvent. This is considered to be caused by a decrease in interfacial tension due to the fact that the phosphor powder and the binder resin are contained as a solid content. The same applies to the following embodiments.

<Example 2>
As Example 2, a phosphor paste is prepared by mixing a red phosphor, an organic solvent, and an organic binder resin so as to have the following viscosity and interfacial tension.
Red phosphor: (Y, Eu) (P, V) O ₄
Organic binder resin: ethyl cellulose Organic solvent: terpineol, dipropylene glycol monopropyl ether, 1,3-butylene glycol The phosphor paste was produced in the same manner as in Example 1. The resulting phosphor paste of Example 2 has a viscosity of 66000 Pa · s (at room temperature of 25 degrees). The interfacial tension of the organic solvent was measured in the same manner as in Example 1.

  The interfacial tension in the organic solvent in the phosphor paste of Example 2 is 32.5 mN / m. At this time, the interfacial tension of the phosphor paste of Example 2 is 25.5 mN / m.

<Example 3>
As Example 3, a green phosphor, an organic solvent, and an organic binder resin are mixed so as to have the viscosity and interfacial tension shown below to prepare a phosphor paste.
Green phosphor: (Zn, Mn) ₂ SiO ₄
Organic binder resin: ethyl cellulose Organic solvent: terpineol, 3-methoxybutyl acetate, 2-phenoxyethanol The phosphor paste was produced in the same manner as in Example 1. The resulting phosphor paste of Example 3 has a viscosity of 57000 Pa · s (at room temperature of 25 degrees). The interfacial tension of the organic solvent was measured in the same manner as in Example 1.

  When the interfacial tension in the organic solvent in the phosphor paste of Example 3 was determined, it was 33 mN / m. At this time, the interfacial tension of the phosphor paste of Example 3 is 26 mN / m.

<Example 4>
As Example 4, a green phosphor, an organic solvent, and an organic binder resin are mixed so as to have the viscosity and interfacial tension shown below to prepare a phosphor paste.
Green phosphor: (Zn, Mn) ₂ SiO ₄
Organic binder resin: ethyl cellulose Organic solvent: terpineol, diethylene glycol monobutyl ether acetate, N-methylpyrrolidone A phosphor paste was prepared in the same manner as in Example 1. The resulting phosphor paste of Example 4 has a viscosity of 62000 Pa · s (at room temperature of 25 degrees). The interfacial tension of the organic solvent was measured in the same manner as in Example 1.

  The interfacial tension in the organic solvent in the phosphor paste of Example 4 is 34.5 mN / m. At this time, the interfacial tension of the phosphor paste of Example 4 is 29 mN / m.

<Example 5>
As Example 5, a blue phosphor, an organic solvent, and an organic binder resin are mixed so as to have the viscosity and interfacial tension shown below to prepare a phosphor paste.
Blue phosphor: (Ba, Eu) MgAl ₁₀ O ₁₇
Organic binder resin: ethyl cellulose Organic solvent: terpineol, dipropylene glycol monopropyl ether, benzyl alcohol The phosphor paste was prepared in the same manner as in Example 1. The resulting phosphor paste of Example 5 has a viscosity of 74000 Pa · s (at room temperature of 25 degrees). The interfacial tension of the organic solvent was measured in the same manner as in Example 1.

  The interfacial tension in the organic solvent in the phosphor paste of Example 5 is 33 mN / m. At this time, the interfacial tension of the phosphor paste of Example 5 is 26 mN / m.

<Example 6>
As Example 6, a green phosphor, an organic solvent, and an organic binder resin are mixed at a weight percent by weight so as to obtain the viscosity and interfacial tension shown below, thereby preparing a phosphor paste.
Blue phosphor: (Ba, Eu) MgAl ₁₀ O ₁₇
Organic binder resin: ethyl cellulose Organic solvent: terpineol, 3-methoxybutyl acetate, 2-phenoxyethanol The phosphor paste was produced in the same manner as in Example 1. The resulting phosphor paste of Example 6 has a viscosity of 68000 Pa · s (at room temperature of 25 degrees). The interfacial tension of the organic solvent was measured in the same manner as in Example 1.

  The interfacial tension in the organic solvent in the phosphor paste of Example 6 is 31 mN / m. At this time, the interfacial tension of the phosphor paste of Example 6 is 23.5 mN / m.

  The above Examples 1 to 6 were applied to the back plate of the PDP, color mixing was evaluated, and the results are summarized in Table 1 below. When the color mixing failure does not occur between the phosphor pastes, ◯ was evaluated. When the phosphor paste moved but did not reach the failure, Δ was evaluated, and when the color mixing failure occurred, X was evaluated.

  If the interfacial tension difference between the phosphor pastes is 2.0 mN / m or less, color mixing failure does not occur. At this time, if the difference in the interfacial tension of the solvent is 1.5 mN / m or less, it is not defective. If the difference in the interfacial tension of the solvent is 0.5 mN / m or less, the interfacial tension difference of the paste is also 0 mN / m. m, no color mixing occurs.

5. Summary As described above, the phosphor paste of the three primary colors of the present invention is the first primary phosphor paste composed of the first phosphor paste, the second phosphor paste, and the third phosphor paste. A difference in interfacial tension between two phosphor pastes selected from the phosphor paste, the second phosphor paste, and the third phosphor paste is 2.0 mN / m or less, respectively.

  Thereby, even if phosphor pastes of different colors come into contact with each other, one is prevented from being drawn into the other, and color mixing is suppressed.

  As described above, the phosphor paste of the present invention contributes to the improvement in workability and yield when manufacturing a PDP because the characteristics involved in nozzle coating are controlled within an appropriate range. In addition, by applying a stable paste, it is possible to improve the reliability of the PDP.

DESCRIPTION OF SYMBOLS 1 Front plate 2 Back plate 3 Discharge space 4 Front substrate 5 Scan electrode 6 Sustain electrode 7 Display electrode 8 Dielectric layer 9 Protective film 10 Back substrate 11 Insulator layer 12 Data electrode 13 Partition 14R Red phosphor layer 14G Green phosphor layer 14B Blue phosphor layer 15 Discharge cell

Claims (5)

In the phosphor paste of three primary colors constituted by the first phosphor paste, the second phosphor paste, and the third phosphor paste, the first phosphor paste, the second phosphor paste, and the third phosphor paste A phosphor paste of three primary colors, wherein the difference in interfacial tension between two phosphor pastes selected from the phosphor paste is 2.0 mN / m or less. The first phosphor paste includes a first phosphor powder, a first binder resin, and at least one organic solvent, and the second phosphor paste includes a second phosphor powder, a first phosphor powder, 2 binder resin and at least one organic solvent, and the third phosphor paste includes a third phosphor powder, a third binder resin, and at least one organic solvent, 2. The difference in interfacial tension between organic solvents of two phosphor pastes selected from the first, second, and third phosphor pastes is less than 1.5 mN / m, respectively. The phosphor paste of the three primary colors described in 1. A difference in interfacial tension between two phosphor pastes selected from the first phosphor paste, the second phosphor paste, and the third phosphor paste is 0.5 mN / m or less, respectively. Three primary color phosphor pastes. The difference in interfacial tension between two organic solvents selected from the first organic solvent, the second organic solvent, and the third organic solvent is 0.5 mN / m or less, respectively. Item 3. The primary color phosphor paste according to Item 1. A plasma display panel comprising a phosphor layer comprising the phosphor paste of the three primary colors according to claim 1.

Images