JP2005060562A - Method for producing vacuum ultraviolet-exited fluorescent material, vacuum ultraviolet-excited fluorescent material, and plasma display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a vacuum ultraviolet-excited fluorescent material having high emission intensity; and to provide the vacuum ultraviolet-excited fluorescent material and a plasma display panel having panel brightness improved by using the vacuum ultraviolet-excited fluorescent material. <P>SOLUTION: The surface of a fluorescent particle obtained by firing a precursor synthesized in a liquid phase is subjected to an etching treatment. The method for producing the vacuum ultraviolet-excited fluorescent material involves regulating the average particle diameter of the fluorescent particle so as to be ≥20 nm and ≤2 μm. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a phosphor and a method for producing the same, and more particularly to a method for producing a vacuum ultraviolet excitation phosphor suitable for a phosphor for a plasma display panel, a vacuum ultraviolet excitation phosphor and a plasma display panel.

  A plasma display panel (hereinafter abbreviated as “PDP”) includes a large number of discharge cells filled with a discharge gas between two glass substrates provided with electrodes. The discharge cell has a phosphor layer, and generates a vacuum ultraviolet ray for exciting and emitting the phosphor by applying a voltage between the electrodes and selectively discharging.

  In order to improve the light emission intensity of the phosphor, it is generally performed to provide a rough surface on the particle surface to increase the surface area and efficiently receive vacuum ultraviolet rays. Since a strong electric field tends to concentrate on the convex part, if the discharge is repeated for a long time, the convex part peels off and the life characteristics of the phosphor deteriorate. In order to prevent this, the weak portions of the convex portions present on the particle surface are removed by physical treatment or chemical treatment, and the deterioration of the luminous efficiency is suppressed, and the phosphors and phosphors having long lifetimes are suppressed. A manufacturing method is known (see, for example, Patent Document 1).

On the other hand, vacuum ultraviolet rays have a property that they are easily absorbed by impurities on the surface of the phosphor particles. Furthermore, in the vicinity of the surface of the phosphor particles that are easily affected by the firing atmosphere, impurities that inhibit light emission are likely to be mixed into the crystal and the activator is oxidized. Therefore, in the vacuum ultraviolet excited phosphor particularly susceptible to the influence of the composition of the phosphor particle surface, in order to improve the emission intensity, impurities such as unreacted substances and by-products attached to the particle surface and the surface of the phosphor particle It is important to remove the layer. For example, as a method for removing unreacted substances adhering to the surface of the phosphor particles, a method of washing with a 1 to 20% hydrochloric acid solution is known (for example, see Patent Document 2).
JP-A-5-255665 JP 2001-172622 A

  However, the phosphor described in Patent Document 1 is an electroluminescent phosphor from which a low-intensity convex portion is removed, and a minute amount of impurities adhering to the surface of the phosphor particles and the surface layer of the phosphor particles are uniform. It was not removed and it did not efficiently receive vacuum ultraviolet light. Further, with the recent miniaturization of discharge cells, it is required to densely fill the phosphor layer with the phosphor, but the average particle size of the phosphor described in Patent Document 1 is 15 to 60 μm, In addition, since the surface has irregularities and the shape is not uniform, the discharge cell cannot be sufficiently filled with the phosphor, which may lead to a decrease in the light emission intensity of the panel. On the other hand, in the method described in Patent Document 2, a phosphor having a particle size of about 50 μm obtained by a solid-phase reaction is used, and there is no disclosure of the particle size distribution, and the conditions under which the effect of etching cannot be sufficiently obtained. It was.

  An object of the present invention is to provide a method for producing a vacuum ultraviolet excitation phosphor capable of producing a vacuum ultraviolet excitation phosphor having a high emission intensity even if the excitation light intensity is the same, a vacuum ultraviolet excitation phosphor, and the vacuum ultraviolet excitation. An object of the present invention is to provide a plasma display panel in which the emission intensity of the panel is improved by using a phosphor.

  In order to solve the above-mentioned problem, according to the method for producing a vacuum ultraviolet-excited phosphor of the invention described in claim 1, a phosphor obtained by synthesizing a precursor in a liquid phase and firing the precursor. Etching is performed on the surface of the particles.

  According to a second aspect of the present invention, in the method for producing a vacuum ultraviolet-excited phosphor according to the first aspect, the average particle diameter of the phosphor particles is 20 nm or more and 2 μm or less.

  Invention of Claim 3 is a manufacturing method of the vacuum ultraviolet ray excitation fluorescent substance of Claim 1 or 2, The particle size distribution of the said fluorescent substance particle is less than +/- 50% of an average particle diameter, It is characterized by the above-mentioned. To do.

  The method for producing a vacuum ultraviolet-excited phosphor according to a fourth aspect of the invention is characterized in that an etching process is performed on the surface of the phosphor particles having an average particle diameter of 20 nm to 2 μm.

  According to a fifth aspect of the present invention, in the method for producing a vacuum ultraviolet-excited phosphor according to the fourth aspect, the particle size distribution of the phosphor particles is within ± 50% of the average particle size.

  The method for producing a vacuum ultraviolet-excited phosphor according to claim 6 is characterized in that the surface of the phosphor particles having a particle size distribution within ± 50% of the average particle size is etched.

  Invention of Claim 7 is a manufacturing method of the vacuum ultraviolet-excited fluorescent substance as described in any one of Claims 1-6. WHEREIN: Performing the said etching process using 0.001N or more and less than 6N strong acid. Features.

  The invention according to claim 8 is the method for producing a vacuum ultraviolet ray-excited phosphor according to claim 7, wherein the etching treatment is performed using a strong acid of 0.001N or more and less than 2.5N.

  According to a ninth aspect of the present invention, in the method for producing a vacuum ultraviolet-excited phosphor according to the seventh aspect, the etching treatment is performed using a strong acid of 0.001 N or more and less than 0.25 N.

  The invention according to claim 10 is characterized in that the surface of the phosphor particles is etched using a strong acid of 0.001 N or more and less than 0.25 N.

  Invention of Claim 11 is a manufacturing method of the vacuum ultraviolet ray excitation fluorescent substance as described in any one of Claims 1-10, The quantity of the fluorescent substance particle removed by the said etching process is 1.5 mol% or more and 20 mol It is characterized by being less than%.

  The invention according to claim 12 is characterized in that the surface of the phosphor particles is etched so as to remove an amount of 1.5 mol% or more and less than 20 mol%.

Invention according to claim 13, in the manufacturing method of VUV-excited phosphor according to any one of claims 1 to 12, wherein the phosphor particles Zn ₂ SiO _4: characterized in that the Mn ²⁺ And

  The vacuum ultraviolet-excited phosphor of the invention described in claim 14 is manufactured by the vacuum ultraviolet-excited phosphor manufacturing method according to any one of claims 1-13.

  A plasma display panel according to a fifteenth aspect of the present invention includes the vacuum ultraviolet-excited phosphor according to the fourteenth aspect in a phosphor layer.

    According to the first aspect of the present invention, since the phosphor particles produced by the liquid phase method have a uniform composition, the entire particles can be uniformly etched, and the effect of etching tends to appear. Further, by removing impurities adhering to the surface uniformly, vacuum ultraviolet rays can be received efficiently, and the luminous efficiency can be improved even when the excitation light intensity is the same.

  According to the second aspect of the present invention, the phosphor particles having a particle size of 2 μm or less are likely to have an effect of etching treatment, and since the particles are fine particles, the phosphor layer of the PDP can be efficiently filled with the phosphor. The emission intensity of the PDP panel can be further improved.

  According to the invention described in claim 3, the phosphor particles having a narrow particle size distribution can uniformly etch the entire particles, and the effect of the etching treatment is likely to appear. Further, since the particle diameters are uniform, the phosphor layer of the PDP can be efficiently filled with the phosphor, and the emission intensity of the PDP panel can be further improved.

  According to the invention described in claim 4, phosphor particles having a size of 2 μm or less are likely to have an effect of etching treatment, and vacuum ultraviolet rays are efficiently received by removing impurities adhering to the surface, and the excitation light intensity is the same. Even if it is a case, luminous efficiency can be improved.

  According to the invention described in claim 5, the phosphor particles having a narrow particle size distribution can uniformly etch the entire particles, and the effect of the etching treatment tends to appear. Further, since the particle diameters are uniform, the phosphor layer of the PDP can be efficiently filled with the phosphor, and the emission intensity of the PDP panel can be further improved.

  According to the sixth aspect of the invention, by performing the etching process on the phosphor particles having a narrow particle size distribution, the entire particles can be uniformly etched, and the etching effect is likely to appear. Further, by removing impurities adhering to the surface uniformly, vacuum ultraviolet rays can be received efficiently, and the luminous efficiency can be improved even when the excitation light intensity is the same.

  According to the seventh aspect of the present invention, the impurities and the surface layer on the surface of the phosphor particles are removed by performing an etching process using a strong acid of 0.001 N or more and less than 6 N, and light is efficiently received and emitted. Strength can be improved.

  According to the invention described in claim 8, a more preferable effect can be obtained by using a strong acid of less than 2.5N.

  According to the ninth aspect of the present invention, the effect of improving the emission intensity is particularly high by performing the etching process using a strong acid of 0.001N or more and less than 0.25N. That is, only impurities on the surface of the phosphor particles can be efficiently dissolved and removed, the concentration of the eluted substance is low, and re-adsorption hardly occurs on the particle surface. Further, the concentration of strong acid does not easily occur during etching, and the particle surface is uniformly etched. As described above, impurities and surface layers on the surface of the phosphor particles can be uniformly removed, and even when the excitation light intensity is the same, it is possible to efficiently receive ultraviolet rays and improve the emission intensity.

  According to the tenth aspect of the present invention, the effect of improving the emission intensity is particularly high by performing the etching treatment using a strong acid of 0.001N or more and less than 0.25N. That is, only impurities on the surface of the phosphor particles can be efficiently dissolved and removed, the concentration of the eluted substance is low, and re-adsorption hardly occurs on the particle surface. Further, the concentration of strong acid does not easily occur during etching, and the particle surface is uniformly etched. As described above, impurities and surface layers on the surface of the phosphor particles can be uniformly removed, and even when the excitation light intensity is the same, it is possible to efficiently receive ultraviolet rays and improve the emission intensity.

  According to invention of Claim 11, when removing the impurity adhering to the surface of fluorescent substance particle and a surface layer, it can carry out efficiently industrially.

  According to the twelfth aspect of the present invention, vacuum ultraviolet rays are efficiently received by removing impurities and surface layers adhering to the surface of the phosphor particles, and the emission intensity is improved even when the excitation line intensity is the same. can do. In addition, the etching process can be performed industrially efficiently.

  According to the thirteenth aspect of the present invention, it is possible to manufacture a vacuum ultraviolet excitation phosphor suitable for the green phosphor layer of the PDP.

  According to the invention described in claim 14, by being manufactured by the manufacturing method according to any one of claims 1 to 13, impurities and a surface layer attached to the surface of the phosphor particles are removed, Even when the vacuum ultraviolet rays are efficiently received and the excitation light intensity is the same, the light emission efficiency can be improved.

  According to the fifteenth aspect of the present invention, by including the vacuum ultraviolet ray-excited phosphor according to the fourteenth aspect in the phosphor layer, light emission of the PDP panel can be achieved without increasing the intensity of the vacuum ultraviolet light generated in the discharge cell. Strength can be improved.

  Embodiments of the present invention will be described below. First, the vacuum ultraviolet excitation phosphor according to the present invention will be described. The present inventors have found that the original luminance of the phosphor is impaired by the absorption of ultraviolet rays by a small amount of impurities remaining on the surface of the phosphor particles obtained after firing. This tendency tends to appear more prominently as the wavelength of the excitation light becomes shorter. In particular, in the phosphor used for the PDP, the influence of impurities becomes significant. Further, as described above, in the vicinity of the surface of the phosphor particles that are easily influenced by the firing atmosphere, impurities that inhibit light emission are likely to be mixed into the crystal, and the activator is oxidized.

  The phosphor according to the present invention is etched on the surface of phosphor particles in a vacuum ultraviolet ray excited phosphor (hereinafter referred to as “phosphor”) that is particularly susceptible to emission intensity due to the composition near the surface layer. By applying the treatment, impurities attached to the surface and the surface layer of phosphor particles (hereinafter referred to as “impurities”) are removed to efficiently receive vacuum ultraviolet rays, thereby improving the emission intensity. For example, phosphor particles to be etched are manufactured by a liquid phase method, or the average particle size is 20 nm to 2 μm, or the particle size distribution is ± 50 of the average particle size. % Is preferable.

  Here, the impurities adhering to the surface refer to unreacted substances that remain unreacted in the baking step described later, and a trace amount of substances other than the phosphor composition generated by the baking.

  The etching process is performed to remove impurities and the like on the surface of the phosphor particles. Only the impurities adhering to the surface may be removed, or a surface layer with low luminous efficiency on the surface of the phosphor particles may be removed. It may be removed together with impurities. The surface layer having a low luminous efficiency on the surface of the phosphor particles refers to a range from about 0% to 20% of the diameter from the surface, and preferably 1.5 mol% or more and less than 20 mol%.

  Here, the “average particle diameter” refers to an average value obtained by measuring the particle diameter of 300 phosphor particles using an electron microscope (for example, S-900 manufactured by Hitachi, Ltd.). The term “particle size” as used herein refers to the length of the phosphor particles when the phosphor particles are cubic or octahedral so-called normal crystals. When it is not a normal crystal, for example, when the phosphor particles are spherical, rod-like or tabular, it means the diameter when considering a class equivalent to the volume of the phosphor particles.

  By removing impurities on the surface of the phosphor particles that absorb vacuum ultraviolet rays by the etching process, the phosphor particles can efficiently receive vacuum ultraviolet rays, and as a result, the original luminance of the phosphor can be exhibited, and the emission intensity And the emission intensity of the panel when used in the phosphor layer of the PDP can be improved.

  The phosphor particles produced by the liquid phase synthesis method have a small amount of unreacted substances and the composition between the phosphors is uniform, so that it is easy to perform uniform etching operations on the entire particles, The effect is likely to appear.

  For the same reason as above, the phosphor particles having a narrow particle size distribution tend to exhibit an etching effect, and the particle size distribution has a distribution of ± 50% or less of the average particle size, and this effect is particularly remarkable.

  In addition, the phosphor particles having a particle size of 2 μm or less tend to exhibit an etching effect. This seems to be due to the large surface area per unit volume. There is a tendency for the effect to increase as the particle size decreases.

  Although the example of a specific compound of the inorganic fluorescent substance used as such a fluorescent substance of this invention is shown, this invention is not limited to these.

[Blue light emitting phosphor compound]
(BL-1): Sr ₂ P ₂ O ₇ : Sn ⁴⁺
(BL-2): Sr ₄ Al ₁₄ O ₂₅ : Eu ²⁺
(BL-3): BaMgAl ₁₀ O ₁₇ : Eu ²⁺
(BL-4): SrGa ₂ S ₄ : Ce ³⁺
(BL-5): CaGa ₂ S ₄ : Ce ³⁺
(BL-6): (Ba, Sr) (Mg, Mn) Al ₁₀ O ₁₇ : Eu ²⁺
(BL-7): (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) 6Cl ₂ : Eu ²⁺
(BL-8): ZnS: Ag
(BL-9): CaWO ₄
(BL-10): Y ₂ SiO ₅ : Ce
(BL-11): ZnS: Ag, Ga, Cl
(BL-12): Ca ₂ B ₅ O ₉ Cl: Eu ²⁺
(BL-13): BaMgAl ₁₄ O ₂₃ : Eu ²⁺
(BL-14): BaMgAl ₁₀ O ₁₇ : Eu ²⁺ , Tb ³⁺ , Sm ²⁺
(BL-15): BaMgAl ₁₄ O ₂₃ : Sm ²⁺
(BL-16): Ba ₂ Mg ₂ Al ₁₂ O ₂₂ : Eu ²⁺
(BL-17): Ba ₂ Mg ₄ Al ₈ O ₁₈ : Eu ²⁺
(BL-18): Ba ₃ Mg ₅ Al ₁₈ O ₃₅ : Eu ²⁺
(BL-19): (Ba, Sr, Ca) (Mg, Zn, Mn) Al ₁₀ O ₁₇ : Eu ²⁺

[Green light-emitting phosphor compound]
(GL-1): (Ba, Mg) Al ₁₆ O ₂₇ : Eu ²⁺ , Mn ²⁺
(GL-2): Sr ₄ Al ₁₄ O ₂₅ : Eu ²⁺
(GL-3): (Sr, Ba) Al ₂ Si ₂ O ₈ : Eu ²⁺
(GL-4): (Ba, Mg) ₂ SiO ₄ : Eu ²⁺
(GL-5): Y ₂ SiO ₅ : Ce ³⁺ , Tb ³⁺
(GL-6): Sr ₂ P ₂ O ₇ —Sr ₂ B ₂ O ₅ : Eu ²⁺
(GL-7): (Ba, Ca, Mg) ₅ (PO ₄ ) ₃ Cl: Eu ²⁺
(GL-8): Sr ₂ Si ₃ O ₈ -2SrCl ₂ : Eu ²⁺
(GL-9): Zr ₂ SiO ₄ , MgAl ₁₁ O ₁₉ : Ce ³⁺ , Tb ³⁺
(GL-10): Ba ₂ SiO ₄ : Eu ²⁺
(GL-11): ZnS: Cu, Al
(GL-12): (Zn, Cd) S: Cu, Al
(GL-13): ZnS: Cu, Au, Al
(GL-14): Zn ₂ SiO ₄ : Mn ²⁺
(GL-15): ZnS: Ag, Cu
(GL-16) :( Zn, Cd) S: Cu
(GL-17): ZnS: Cu
(GL-18): Gd ₂ O ₂ S: Tb
(GL-19): La ₂ O ₂ S: Tb
(GL-20): Y ₂ SiO ₅ : Ce, Tb
(GL-21): Zn ₂ GeO ₄ : Mn
_{(GL-22): CeMgAl 11} O 19: Tb
(GL-23): SrGa ₂ S ₄ : Eu ²⁺
(GL-24): ZnS: Cu, Co
(GL-25): MgO.nB ₂ O ₃ : Ce, Tb
(GL-26): LaOBr: Tb, Tm
(GL-27): La ₂ O ₂ S: Tb
(GL-28): SrGa ₂ S ₄ : Eu ²⁺ , Tb ³⁺ , Sm ²⁺

[Red-emitting phosphor compound]
(RL-1): Y ₂ O ₂ S: Eu ³⁺
(RL-2): (Ba, Mg) ₂ SiO ₄ : Eu ³⁺
(RL-3): Ca ₂ Y ₈ (SiO ₄ ) ₆ O ₂ : Eu ³⁺
(RL-4): LiY ₉ (SiO ₄ ) ₆ O ₂ : Eu ³⁺
(RL-5): (Ba, Mg) Al ₁₆ O ₂₇ : Eu ³⁺
(RL-6): (Ba, Ca, Mg) ₅ (PO ₄ ) ₃ Cl: Eu ³⁺
(RL-7): YVO ₄ : Eu ³⁺
_{(RL-8): YVO 4} : Eu 3+, Bi 3+
(RL-9): CaS: Eu ³⁺
(RL-10): Y ₂ O ₃ : Eu ³⁺
(RL-11): 3.5MgO, 0.5MgF ₂ GeO ₂ : Mn
(RL-12): YAlO ₃ : Eu ³⁺
(RL-13): YBO ₃ : Eu ³⁺
(RL-14) :( Y, Gd) BO ₃ : Eu ³⁺

In particular, as the phosphor according to the present invention, the above (GL-14) Zn ₂ SiO ₄ : Mn ²⁺ is preferable.

  Next, a method for manufacturing the phosphor according to the present invention will be described. The method for producing a vacuum ultraviolet-excited phosphor according to the present invention includes a precursor forming step for forming a phosphor precursor, a firing step for obtaining phosphor particles by firing the precursor obtained by the precursor forming step, and firing. An etching process is included in which the surface of the phosphor particles obtained in the process is etched to remove impurities and the like.

  First, a precursor formation process is demonstrated. In the precursor forming step according to the present invention, the precursor is preferably synthesized by a liquid phase method (also referred to as “liquid phase synthesis method”). A precursor is an intermediate product of a phosphor, and, as will be described later, phosphor particles can be obtained by firing this precursor at a predetermined temperature in a firing step.

  The liquid phase method is a method for producing (synthesizing) a precursor in the presence of a liquid or in a liquid. In the liquid phase method, since the phosphor raw material is reacted in the liquid phase, a reaction between element ions constituting the phosphor is performed, and a stoichiometrically high purity phosphor is easily obtained. Compared with the solid phase method in which the phosphor is produced while repeating the solid phase reaction and the pulverization step, particles having a small particle size can be obtained without performing the pulverization step. It is possible to prevent lattice defects in the crystal and prevent a decrease in light emission efficiency.

  In the present invention, as the liquid phase method, any conventionally known crystallization method and coprecipitation method including cooling crystallization can be used, and among them, the reaction crystallization method can be preferably used.

  The reaction crystallization method uses a crystallization phenomenon to produce a precursor by mixing a solution (or source gas) containing an element as a phosphor raw material in a liquid phase (or in a gas phase). Is the method. Crystallization is a phenomenon in which the solid phase precipitates from the liquid phase when the physical or chemical environment changes due to cooling, evaporation, pH adjustment, concentration, etc., or when the state of the mixed system changes due to a chemical reaction. This refers to the phenomenon that occurs. In the reaction crystallization method, it means a production method by physical and chemical operations that can cause the occurrence of such a crystallization phenomenon.

  Any solvent may be used as the solvent for applying the reaction crystallization method as long as the reaction raw material dissolves, but water is preferable from the viewpoint of ease of supersaturation control. In the case of using a plurality of reaction raw materials, the addition order of the raw materials may be simultaneous or different, and an appropriate order can be appropriately assembled depending on the activity.

  In the formation of precursors, it is possible to produce a fluorescent material with a narrower particle size distribution by adding two or more raw material solutions into a poor solvent in the presence of protective colloids, including reactive crystallization. Therefore, this is a preferred embodiment. Moreover, it is more preferable to adjust various physical properties such as the temperature during the reaction, the addition rate, the stirring rate, and the pH depending on the type of the phosphor, and ultrasonic waves may be irradiated during the reaction. A surfactant or polymer may be added to control the particle size. It is also a preferred embodiment that the liquid is concentrated and / or aged as necessary after the addition of the raw materials.

  The protective colloid functions to prevent aggregation of the finely divided precursor particles, and various polymer compounds can be used regardless of natural or artificial, and among them, proteins can be preferably used.

  Examples of the protein include gelatin, water-soluble protein, and water-soluble glycoprotein. Specific examples include albumin, ovalbumin, casein, soy protein, synthetic protein, and genetically synthesized protein.

  Examples of gelatin include lime-processed gelatin and acid-processed gelatin, and these may be used in combination. Furthermore, a hydrolyzate of these gelatins and an enzyme degradation product of these gelatins may be used.

  Further, the protective colloid does not need to have a single composition, and various binders may be mixed. Specifically, for example, a graft polymer of the above gelatin and another polymer can be used.

  The average molecular weight of the protective colloid is preferably 10,000 or more, more preferably 10,000 to 300,000, and particularly preferably 10,000 to 30,000.

  The protective colloid can be added to one or more of the raw material solutions. You may add to all the raw material solutions. The particle size of the precursor can be controlled by the amount of the protective colloid added and the addition rate of the reaction solution.

  Various properties of the phosphor such as the particle size, particle size distribution, and light emission properties of the phosphor particles after firing are greatly affected by the properties of the precursor. Therefore, in this way, it is preferable to make the precursor sufficiently small by controlling the particle size of the precursor in the precursor forming step. When the precursor is made fine particles, the precursors tend to aggregate. Therefore, it is very effective to synthesize precursors while preventing aggregation of the precursors by adding protective colloids, and particle size control becomes easy. When the reaction is carried out in the presence of a protective colloid, it is necessary to give sufficient consideration to the control of the particle size distribution of the precursor and the exclusion of impurities such as secondary salts.

  In the precursor formation step, the particle size is controlled appropriately as described above to synthesize the precursor, and then the precursor is recovered by a method such as filtration, evaporation to dryness, and centrifugation as necessary. Thereafter, preferably, washing and desalting treatment steps are performed.

  The desalting treatment step is a step for removing impurities such as by-salts from the precursor, and various membrane separation methods, coagulation sedimentation methods, electrodialysis methods, methods using ion exchange resins, nudelle washing methods, etc. are applied. Can do.

  In the present invention, from the viewpoint of improving the productivity of the precursor and sufficiently removing the secondary salt and impurities, and preventing the coarsening of the particles and the expansion of the particle size distribution, the electrical conductivity after the precursor desalting is The range is preferably 0.01 to 20 mS / cm, more preferably 0.01 to 10 mS / cm, and particularly preferably 0.01 to 5 mS / cm.

  By adjusting the electric conductivity as described above, it is effective to improve the emission intensity of the finally obtained phosphor. In addition, what kind of method can be used for the measuring method of electrical conductivity, for example, a commercially available electrical conductivity measuring device can be used.

  After the desalting treatment step, a drying step may be further performed. The drying step is preferably performed after washing or desalting, and can be performed by any method such as vacuum drying, airflow drying, fluidized bed drying, and spray drying. Although a drying temperature is not specifically limited, It is preferable that it is the temperature near the temperature which the used solvent evaporates, and it is preferable that it is specifically the range of 50-300 degreeC. When the drying temperature is high, firing may be performed simultaneously with drying. In this case, a phosphor may be obtained without performing the firing treatment described below.

  Next, the firing process will be described. The phosphors according to the present invention, such as rare earth borate phosphors, silicate phosphors and aluminate phosphors, can be obtained by firing each precursor. Here, the conditions (baking conditions) for the baking treatment will be described.

  Any method may be used in the firing step, and the firing temperature and time may be adjusted as appropriate. For example, a desired phosphor can be obtained by filling the precursor in an alumina boat and firing it at a predetermined temperature in a predetermined gas atmosphere. The gas atmosphere can be appropriately selected from conditions such as a reducing atmosphere, an oxidizing atmosphere, the presence of sulfide, an inert gas, etc., depending on the composition of the precursor.

  As an example of preferable firing conditions, there may be firing in the atmosphere between 600 ° C. and 1800 ° C. for an appropriate time. Also effective is a method in which baking is performed at 1100 ° C. for 90 minutes in the air after baking at about 800 ° C. to oxidize organic substances.

  As the baking apparatus (baking container), any apparatus known at present can be used. For example, a box furnace, a crucible furnace, a cylindrical tube type, a boat type, a rotary kiln and the like are preferably used.

  Moreover, you may add a sintering inhibitor as needed at the time of baking. Of course, it is not necessary to add when there is no need to add. When a sintering inhibitor is added, it may be added as a slurry at the time of forming the precursor, or a powdery sintering inhibitor may be mixed with the dried precursor and fired.

The sintering inhibitor is not particularly limited, and is appropriately selected depending on the type of phosphor and firing conditions. For example, depending on the firing temperature range of the phosphor, a metal oxide such as TiO ₂ is used for baking at 800 ° C. or lower, SiO ₂ is used for baking at 1000 ° C. or lower, and Al ₂ O ₃ is used for baking at 1700 ° C. or lower. Are preferably used.

  Furthermore, you may give a reduction process or an oxidation process after baking as needed. In addition, after the firing step, cooling treatment, surface treatment, dispersion treatment, or the like may be performed, or classification may be performed.

  The cooling process is a process of cooling the fired product obtained in the firing process, and it is possible to cool the fired product while filling the fired device.

  The cooling treatment is not particularly limited, and can be appropriately selected from known cooling methods. For example, either a method of lowering the temperature by leaving alone or a method of forcibly lowering the temperature while controlling the temperature using a cooler. It may be.

  The phosphor produced in the present invention can be subjected to surface treatment such as adsorption and coating for various purposes. The point at which the surface treatment is performed depends on the purpose, and the effect becomes more prominent when appropriately selected. For example, when the surface of the phosphor is coated with an oxide containing at least one element selected from Si, Ti, Al, Zr, Zn, In, and Sn at any point before the dispersion treatment process, The decrease in the crystallinity of the phosphor can be suppressed, and the decrease in the emission intensity can be suppressed by preventing the excitation energy from being captured by the surface defects of the phosphor. Moreover, when the surface of the phosphor is coated with an organic polymer compound or the like at any point after the dispersion treatment step, characteristics such as weather resistance are improved, and a phosphor having excellent durability can be obtained. The thickness and coverage of the coating layer when these surface treatments are performed can be arbitrarily controlled as appropriate.

  Next, the distributed processing process will be described. In the present invention, the following dispersion treatment is preferably performed on the phosphor particles obtained in the firing step.

  As a dispersion processing method, for example, a high-speed stirring type impeller type disperser, a colloid mill, a roller mill, a ball media, a vibrating ball mill, an attritor mill, a planetary ball mill, a sand mill, and the like are moved in the apparatus to collide ( Crush) and those that are atomized by shearing force, or dry type dispersers such as a cutter mill, a hammer mill, and a jet mill, an ultrasonic disperser, and a high-pressure homogenizer.

  Among these, in the present invention, it is particularly preferable to use a wet media type disperser that uses a medium, and it is more preferable to use a continuous wet media type disperser that can be continuously dispersed. A mode in which a plurality of continuous wet media type dispersers are connected in series is also applicable. Here, “continuous dispersion treatment is possible” means that at least the phosphor and the dispersion medium are dispersed and supplied to the disperser without interruption at a constant quantity ratio per hour, and at the same time, manufactured in the disperser. The dispersion is discharged from the disperser without interruption in the form of being pushed out to supply. In the case of using a wet media type disperser that uses a medium as a dispersion treatment step in the phosphor manufacturing method, the dispersion chamber container (vessel) can be appropriately selected from a vertical type and a horizontal type.

  The phosphor particles obtained in the firing step can be made to have a uniform composition and a small amount of unreacted substances by forming a precursor by a liquid phase method in the precursor forming step. In addition, by appropriately controlling the particle size in the precursor formation step, the phosphor particles having a particle size distribution of ± 50% or less of the average particle size can be obtained from the fine particle phosphor having an average particle size of 20 nm to 2 μm. Can do.

  Since the phosphor particles are fine and have a narrow particle size distribution, the phosphor layers provided in the PDP can be densely filled with the phosphor particles, and the emission intensity of the PDP panel can be improved. it can. Further, since the particle size is uniform, excellent light emission without unevenness can be performed.

  In the present invention, from the viewpoint of obtaining phosphor particles having fine particles and a narrow particle size distribution, it is preferable to produce phosphor particles using a liquid phase method, but the phosphor production method of the present invention is not limited to this. It is not limited to. As long as the average particle size of the phosphor particles is 20 nm or more and 2 μm or less, or a method of obtaining a phosphor having a particle size distribution of the phosphor particles within ± 50% of the average particle size, fluorescence can be obtained using various conventionally known methods. The body may be manufactured, and not only the liquid phase method but also the solid phase method may be used.

  Next, the etching process will be described. The etching process can be performed by a method suitable for impurities on the surface of the phosphor particles. For example, a physical method of scraping the surface with fine particles or ion sputtering may be used, but a chemical method such as immersing phosphor particles in an etching solution to dissolve impurities on the surface is effective. is there.

  In addition, in the phosphor according to the present invention, unlike the electroluminescent phosphor, since there is no role of improving the emission intensity by the convex portion on the surface, the viewpoint that the phosphor particles are densely packed in the phosphor layer and From the viewpoint of uniformly etching the surface of the phosphor particles, it is preferable to etch the phosphor particles having little or no convex portions on the particle surface.

  When the etching solution erodes the phosphor particle main body, the emission intensity is lowered, so that the etching needs to be performed carefully.

  The type of etching solution is determined by the content of impurities and the like, and may be acidic or alkaline, and may be an aqueous solution or an organic solvent. However, when an acidic aqueous solution is used, the effect appears remarkably, particularly when a strong acid is used. It is preferable to use it.

  When a strong acid is used, the concentration of the etching solution is preferably 0.001N or more and less than 6N, more preferably 0.001N or more and less than 2.5N, and 0.001N or more and less than 0.25N. Is particularly preferred.

  A desired effect can be obtained by performing an etching treatment using a strong acid of 0.001N or more and less than 6N. In particular, when a strong acid of 0.001N or more and less than 0.25N is used, only impurities can be efficiently dissolved, the concentration of the eluted substance is low, and the removed substance is re-adsorbed on the particle surface. Hateful. Further, it is preferable because the concentration localization of strong acid can be suppressed during etching and the particle surface can be uniformly etched.

  As the concentration of the strong acid increases, the concentration of the eluted substance increases, and the substance removed during the etching process may be re-adsorbed on the particle surface. Further, since the amount of the surface layer of the phosphor particles to be removed increases, it becomes industrially inefficient. In addition, concentration localization is likely to occur during etching, making it difficult to uniformly perform etching between particles, and the effect on the emission intensity is reduced.

  On the other hand, when the concentration of the strong acid is reduced, the amount of impurities and the like on the surface of the phosphor particles is reduced, and the impurities and the like remain on the surface of the particles.

  In addition, since the amount of strong acid required for the etching treatment for the phosphor particles increases, it becomes difficult to handle industrially. Therefore, it is desirable to adjust the concentration of the strong acid to the most preferable value depending on the situation.

  As the strong acid, for example, hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, perchloric acid and the like can be used, but hydrochloric acid, nitric acid and sulfuric acid are preferable, and hydrochloric acid is particularly preferable.

For example, when etching is performed on Zn ₂ SiO ₄ : Mn ²⁺ using hydrochloric acid, Zn ₂ SiO ₄ is dissolved in hydrochloric acid according to the following reaction formula, and the surface layer of the phosphor particles is removed. .
Zn ₂ SiO ₄ + 4HCl → 2ZnCl ₂ + SiO ₂ + 2H ₂ O
From the above reaction formula, it is understood that the amount of dissolved Zn ₂ SiO ₄ , that is, the amount removed by etching treatment can be controlled by changing the amount of strong acid reacted per unit mole of the phosphor. . For example, when 2% of 1 mol of phosphor particles is desired to be dissolved, that is, when it is desired to be removed by etching, it may be reacted with 0.08 mol of hydrochloric acid.

  The amount by which the surface of the phosphor particles is dissolved and removed by the etching process is preferably 1.5 mol% or more and less than 20 mol% of the phosphor particles.

  After the etching, it is preferable to perform a water washing process or the like to remove the etching solution.

  Next, a PDP according to the present invention will be described with reference to FIG. The PDP can be broadly classified from the electrode structure and operation mode into a DC type that applies a DC voltage and an AC type that applies an AC voltage. FIG. 1 shows the configuration of the AC PDP. A schematic example is shown.

  A PDP 1 shown in FIG. 1 is divided into a predetermined shape by two substrates 10 and 20 provided with electrodes 11 and 21, a partition 30 provided between the substrates 10 and 20, and the partition 30. It has a plurality of micro discharge spaces (hereinafter referred to as discharge cells) 31.

  The discharge cell 31 shown in FIG. 1 is a so-called stripe type. When the substrates 10 and 20 are horizontally arranged, the partition walls 30 are provided in parallel at predetermined intervals (that is, in a stripe shape). It is. The structure of the discharge cell is not limited to this stripe type, and may be a grid type discharge cell 41 in which barrier ribs 40 are provided in a grid shape in plan view as shown in FIG. As shown in FIG. 3, a honeycomb-shaped (octagonal) discharge cell 51 may be constituted by a set of bent partition walls 50 which are mutually targeted.

Each discharge cell 31R, 31G, 31B is provided with phosphor layers 35R, 35G, 35B made of a phosphor that emits light in any of red (R), green (G), and blue (B).
Inside each discharge cell 31, a discharge gas is sealed, and at least one point where the electrodes 11 and 21 intersect in a plan view is provided. In the PDP 1 according to the present invention, the phosphor layers 35R, 35G, and 35B are manufactured using the phosphor according to the present invention.

  Hereinafter, each component of PDP1 is demonstrated.

  First, of the two substrates, the configuration on the front plate 10 side arranged on the display side will be described. The front plate 10 transmits visible light emitted from the discharge cells 31 and displays various information on the substrate, and functions as a display screen of the PDP 1.

  A material that transmits visible light, such as soda lime glass (blue plate glass), can be preferably used as the front plate 10. The thickness of the front plate 10 is preferably in the range of 1 to 8 mm, more preferably 2 mm.

  The front plate 10 is provided with a display electrode 11, a dielectric layer 12, a protective layer 13, and the like.

  A plurality of display electrodes 11 are provided on the surface of the front plate 10 facing the back plate 20 and are regularly arranged. The display electrode 11 includes a transparent electrode 11a and a bus electrode 11b, and has a structure in which a bus electrode 11b similarly formed in a strip shape is laminated on a transparent electrode 11a formed in a wide strip shape. The width of the bus electrode 11b is narrower than that of the transparent electrode 11a. Further, the display electrode 11 is orthogonal to the partition wall 30 in plan view. The display electrode 11 is a set of two display electrodes 11 that are arranged to face each other with a predetermined discharge gap.

  A transparent electrode such as a nesa film can be used as the transparent electrode 11a, and the sheet resistance is preferably 100Ω or less. The width of the transparent electrode 7 is preferably in the range of 10 to 200 μm.

  The bus electrode 11b is for lowering the resistance and can be formed by sputtering of Cr / Cu / Cr or the like. The width of the bus electrode 11b is preferably in the range of 5 to 50 μm.

  The dielectric layer 12 covers the entire surface of the front plate 10 on which the display electrodes 11 are disposed. The dielectric layer 12 can be formed of a dielectric material such as low-melting glass. The thickness of the dielectric layer 12 is preferably in the range of 20 to 30 μm.

  The surface of the dielectric layer 12 is entirely covered with the protective layer 13. The protective layer 13 can use an MgO film. As thickness of the protective layer 13, the range of 0.5-50 micrometers is preferable.

  Next, the configuration on the back plate 20 side which is the other of the two substrates 10 and 20 will be described. The back plate 20 is provided with address electrodes 21, dielectric layers 22, partition walls 30, phosphor layers 35R, 35G, and 35B.

  As the back plate 20, soda lime glass (blue plate glass) or the like can be used similarly to the front plate 10. As thickness of the backplate 20, the range of 1-8 mm is preferable, More preferably, it is about 2 mm.

  A plurality of the address electrodes 21 are provided on the surface of the back plate 20 facing the front plate 20. The address electrode 21 is also formed in a strip shape like the transparent electrode 11a and the bus electrode 11b. A plurality of address electrodes 21 are provided at predetermined intervals so as to be orthogonal to the display electrodes 11 in plan view.

  The address electrode 21 can be a metal electrode such as an Ag thick film electrode. The width of the address electrode 21 is preferably in the range of 100 to 200 μm.

  At the time of display, a discharge cell to be displayed is selected by selectively causing trigger discharge between the address electrode 21 and one of the pair of display electrodes 11 and 11. Thereafter, a sustain discharge is performed between the pair of display electrodes 11 and 11 in the selected discharge cell, thereby generating ultraviolet rays caused by the discharge gas, and generating visible light from the phosphor layers 35R, 35G, and 35B. be able to.

  The dielectric layer 22 covers the entire surface of the back plate 20 on which the address electrodes 21 are disposed. The dielectric layer 22 can be formed of a dielectric material such as low melting glass. The thickness of the dielectric layer 22 is preferably in the range of 20 to 30 μm.

  The partition wall 30 is provided on the dielectric layer 22 so as to protrude from the back plate 20 side to the front plate 10 side. The barrier ribs 30 are formed long and are provided on both sides of the address electrode 21, and as described above, the discharge cells 31 are formed in stripes in a plan view.

  The partition wall 30 can be formed of a dielectric material such as low-melting glass. The width of the partition wall 30 is preferably in the range of 10 to 500 μm, and more preferably about 100 μm. The height (thickness) of the partition wall 30 is usually in the range of 10 to 100 μm, and preferably about 50 μm.

  As described above, any one of the phosphor layers 35R, 35G, and 35B that emit light of each color is provided in the discharge cell 31 in a regular order. The thickness of each phosphor layer 35R, 35G, 35B is not particularly limited, but is preferably in the range of 5 to 50 μm.

  In forming the phosphor layers 35R, 35G, and 35B, the phosphor manufactured as described above is dispersed in a mixture of a binder, a solvent, a dispersant, and the like, and a phosphor paste adjusted to an appropriate viscosity is applied to the discharge cell 31. By filling and then drying or baking (baking), phosphor layers 35R, 35G, and 35B having phosphors attached to the partition wall side surface 30a and the bottom surface 30a are formed. The phosphor paste can be adjusted by a conventionally known method.

  When the phosphor paste is applied or filled into the discharge cells 31R, 31G, and 31B, various methods such as a screen printing method, a photoresist film method, and an ink jet method can be used.

  Since the phosphor manufactured by the phosphor manufacturing method according to the present invention has high luminous efficiency, the amount of ultraviolet rays generated in the discharge cells 31R, 31G, and 31B is the same as that of the conventional case, that is, the intensity of the excitation light is the same. However, the PDP 1 with higher emission intensity can be obtained.

  Hereinafter, although Example 1 and Example 2 which concern on this invention are demonstrated, this invention is not limited to this.

[Example 1]
In Example 1, phosphors 1 to 3 were synthesized as green phosphors (Zn ₂ SiO ₄ : Mn ²⁺ ), the obtained phosphor particles were subjected to etching treatment, and the relative emission intensity before and after the etching treatment was evaluated. did. First, synthesis of phosphors 1 to 3 will be described.

1. Synthesis of phosphor (1) Synthesis of phosphor 1 1000 cc of a 5% aqueous solution of low molecular weight gelatin is used as solution A. Zinc nitrate hexahydrate 35.33 g and manganese nitrate hexahydrate 1.79 g are dissolved in pure water to make 500 cc, and this is designated as B solution. 18.25 g of 28% ammonia water is mixed with pure water to make 500 cc. 12.52 g of a 30% colloidal silica aqueous solution manufactured by Aerosil Co., Ltd. is mixed with pure water to make 200 cc, which is designated as D solution.

  While liquid A was vigorously stirred at room temperature, liquid B and liquid C were added at a constant rate over 30 minutes. As a result, a white precipitate was formed. Subsequently, after adding D liquid in A liquid over 4 minutes, solid-liquid separation was performed by the pressure filtration method.

  Next, the recovered cake was dried at 100 ° C. for 24 hours to obtain a dried precursor. The obtained precursor was fired in the atmosphere at 700 ° C. for 3 hours, and further fired in an atmosphere of 100% nitrogen at 1200 ° C. for 3 hours to obtain phosphor 1.

(2) Synthesis of phosphor 2 (1) In the synthesis of phosphor 1, (1) fluorescence except that 1000 cc of pure water is used as solution A, and solution B and solution C are added to solution A in 1 minute. A phosphor was obtained by the same production method as that for body 1. The obtained phosphors were classified, and those having a particle diameter of 650 nm were designated as phosphor 2-1, and those having a particle diameter of 3.2 μm were designated as phosphor 2-2.

(3) Synthesis of phosphor 3 After sufficiently mixing 7.32 g of zinc oxide, 0.7 g of manganese oxide and 6 g of SiO ₂ in a mortar, firing was performed at 1200 ° C. for 3 hours in an atmosphere of 100% nitrogen. The obtained phosphor was classified, and a phosphor having an average particle diameter of 3.6 μm was designated as phosphor 3.
2. Average particle size and particle size distribution The average particle size and particle size distribution were measured from the SEM observation results for the phosphors 1 to 3 obtained above. The results are shown in Table 1.

表１より、（１）の方法により蛍光体１を製造することにより、分級を行わなくとも他と比較して平均粒径が最も小さく、粒径分布の狭い蛍光体が得られることが分かる。

From Table 1, it can be seen that by producing the phosphor 1 by the method (1), a phosphor having the smallest average particle diameter and a narrow particle size distribution can be obtained without classification.

3. Relative emission intensity before and after etching process (phosphor 1)
(1) Etching amount 5 mol%
Next, using the etching solutions A to F shown in Table 2 below, the phosphor 1 was subjected to an etching treatment so that the etching amount was 5 mol%, and the relative light emission intensity before and after the etching treatment was compared. In the etching process, a predetermined amount (223 g) of the phosphor 1 was put into each of the etching solutions A to F, mixed and stirred, and then filtered, washed with water, and dried.

  The etching solutions A to F were hydrochloric acid solutions having different concentrations.

  The relative emission intensity is determined by irradiating each phosphor with vacuum ultraviolet rays using an excimer 146 nm lamp (made by USHIO INC.) In a vacuum chamber of 0.1 to 1.5 Pa. The intensity | strength was measured using the detector (MCPD-3000 (made by Otsuka Electronics Co., Ltd.)). And the peak intensity of light emission was calculated | required by the relative value which made the light emission intensity before an etching process 100 respectively.

但し、エッチング液ＡおよびＦの欄に示したものは本発明に係る比較例である。

However, those shown in the column of the etching solutions A and F are comparative examples according to the present invention.

  From Table 2, it was found that the emission intensity was improved before and after the treatment by applying the etching treatment to the phosphor 1 using the etching solutions B to F. However, when the etching solution F is used, 200 l of the etching solution is required for 223 g of the phosphor 1, which is industrially inefficient, and the use of the etching solutions B to E improves the emission intensity and the industry. It can be seen that it is preferable from the viewpoint of efficiency.

(2) Comparative example (etching amount 30 mol%)
Next, the amount of the etching solution was adjusted using the etching solutions A to C so that the etching amount of the phosphor 1 was 30 mol%, and the relative emission intensity before and after the treatment was evaluated in the same manner as described above. The results are shown in Table 3.

表３より、蛍光体１のエッチング量を３０ｍｏｌ％とした場合、エッチング液Ａ液を除いて発光強度の向上が見られるが、蛍光体の収量が７０％以下となってしまい、工業的には非効率であった。

From Table 3, when the etching amount of the phosphor 1 is set to 30 mol%, the emission intensity is improved except for the etching solution A, but the yield of the phosphor is 70% or less. It was inefficient.

(3) Comparative example (etching amount 0.5 mol%)
Next, using the etching solutions D to F, the amount of the etching solution was adjusted so that the etching amount of the phosphor 1 was 0.5 mol%, and the relative emission intensity before and after the treatment was evaluated in the same manner as described above. The results are shown in Table 4.

表４より、蛍光体１のエッチング量を０．５ｍｏｌ％とした場合、エッチング処理の前後における発光強度の差はほとんどなく、本発明に係る効果が得られていないことがわかる。

From Table 4, it can be seen that when the etching amount of the phosphor 1 is 0.5 mol%, there is almost no difference in emission intensity before and after the etching treatment, and the effect according to the present invention is not obtained.

4). Relative emission intensity before and after etching process (phosphors 1-3, etching amount 2 mol%)
Next, using the etching solution E, the phosphors 1 to 3 were etched so that the etching amount was 2 mol%, and the relative light emission intensity before and after the etching treatment was compared. In addition, except having adjusted the amount of etching liquid in order to change an etching amount, the etching process was performed like the above and the relative light emission intensity was measured. The results are shown in Table 5.

表５より、平均粒径が十分小さく、粒径分布の狭い蛍光体１に対して、エッチング液Ｅでエッチング処理を施した場合の相対発光強度が最も向上していることが分かる。

From Table 5, it can be seen that the relative light emission intensity is most improved when the phosphor 1 having a sufficiently small average particle size and a narrow particle size distribution is etched with the etching solution E.

[Example 2]
In Example 2, a PDP was manufactured using the phosphor obtained in Example 1, and the emission intensity of the PDP panel was evaluated. First, the adjustment of the phosphor paste used for manufacturing the PDP will be described.

1. Adjustment of phosphor paste (1) Adjustment of phosphor paste 1-B After phosphor 1 was etched with etchant E in Example 1 so that the etching amount was 2 mol% as phosphor paste according to the present invention. The phosphor paste was adjusted using phosphor 1-B, which is a phosphor of the above.

A phosphor suspension was prepared with the following composition to obtain a green light-emitting phosphor composition. This was stirred with a stirrer.
Phosphor 1-B 45% by weight
A mixture of terpineol and pentanediol in a 1: 1 ratio of 545.5% by weight
Ethylcellulose (ethoxy group content 50%) 0.3% by weight
Polyoxyethylene alkyl ether 0.2% by weight
The green luminescent composition obtained above was predispersed using a homogenizer manufactured by IKA JAPAN. The pre-dispersion conditions were as follows.
Blade diameter: 20 mm
Rotation speed: 8000rpm
Pre-dispersion time: 2 minutes Following the pre-dispersion, this dispersion treatment was performed under the following dispersion conditions using a horizontal continuous media disperser (DISPERMATT SL-C5 manufactured by VMA-GETZMANN), and the green light emitting phosphor paste 1-B Got.
Disk rotation speed: 5,520 rpm
Bead type: Zirconia Bead diameter: 0.3 mm
Bead filling rate: 70%
Flow rate: 120 ml / min
Dispersion time: 3 minutes

(2) Adjustment of phosphor paste of comparative example (1) The phosphor used in the adjustment of phosphor paste 1-B is changed to phosphor 1 not subjected to etching treatment instead of phosphor 1-B. Except for the above, a phosphor paste was prepared in the same manner to obtain a phosphor paste of a comparative example.

2. Manufacture of PDP (1) Manufacture of PDP1-B The AC surface discharge type PDP 1 having the stripe cell structure shown in FIG. 1 was manufactured as follows.

  First, a transparent electrode is arranged as a transparent electrode 11a at a predetermined position on the glass substrate that will be the front plate 10. Next, the bus electrode 11b is formed on the transparent electrode 11a by sputtering Cr—Cu—Cr and performing photoetching, and the display electrode 11 is formed. Then, a low-melting glass is printed on the surface glass substrate 10 so as to cover the display electrodes 11 and is baked at 500 to 600 ° C. to form the dielectric layer 12. Further, a protective film 13 is formed on the dielectric layer 12 by electron beam evaporation of MgO.

  On the other hand, the address electrode 21 is formed on the back plate 20 by printing an Ag thick film and baking it. Then, partition walls 30 are formed on the back plate 20 and on both sides of the address electrodes 21. The partition walls 30 can be formed by printing low-melting glass with a pitch of 0.2 mm and baking. Further, the phosphor paste 1-B, separately prepared red phosphor paste and blue phosphor paste were applied to the discharge cells 31 partitioned by the barrier ribs 30 by a screen coating method. At this time, one color phosphor paste is used for each discharge cell 31. Thereafter, the phosphor paste was dried or baked to remove organic components in the paste, and phosphor layers 35R, 35G, and 35B having different emission colors were formed in the discharge cells 31R, 31G, and 31B, respectively.

  Then, the front plate 10 and the back plate 20 on which the electrodes 11, 21, etc. are arranged are aligned so that the respective electrode arrangement surfaces face each other, and the periphery is sealed while maintaining a gap of about 1 mm. Sealed with glass (not shown). A gas mixed with xenon (Xe) that generates ultraviolet rays by discharge and neon (Ne) as a main discharge gas is sealed between the substrates 10 and 20 and hermetically sealed, and then aging is performed. PDP was manufactured by the above and was set as PDP1-B.

(2) Manufacture of PDP of Comparative Example As a PDP of a comparative example, the above-described green phosphor paste 1-B is compared with a phosphor paste of a comparative example prepared using phosphor 1 that has not been etched. An example PDP was made.

3. Next, the light emission intensity immediately after lighting of the PDP panel was measured for PDP1-B and the PDP of the comparative example. The results are shown in Table 6. The emission intensity is measured by measuring the white luminance when an equivalent sustain voltage (AC voltage of 170 V) is applied to the electrode, and the relative intensity of PDP1-B when the emission intensity of the PDP of the comparative example is 100. The emission intensity was determined.

表６より、照射される真空紫外線の強度は同じであっても、エッチング処理が施された蛍光体１−Ｂを用いてＰＤＰを製造することによりパネル発光強度を約１割向上することができることが分かる。

From Table 6, even if the intensity of the irradiated vacuum ultraviolet rays is the same, the panel emission intensity can be improved by about 10% by manufacturing the PDP using the phosphor 1-B subjected to the etching treatment. I understand.

It is the perspective view which showed an example of the plasma display panel based on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Plasma display panel 10 Board | substrate 20 Board | substrate 30 Partition 31R, 31G, 31B Discharge cell 35R, 35G, 35B Phosphor layer 40 Partition

Claims (15)

A method for producing a vacuum ultraviolet-excited phosphor, comprising synthesizing a precursor in a liquid phase and etching the surface of the phosphor particles obtained by firing the precursor. In the manufacturing method of the vacuum ultraviolet-excited fluorescent substance of Claim 1,
The method for producing a vacuum ultraviolet-excited phosphor, wherein the phosphor particles have an average particle diameter of 20 nm to 2 μm. In the manufacturing method of the vacuum ultraviolet-excited fluorescent substance of Claim 1 or 2,
A method for producing a vacuum ultraviolet-excited phosphor, wherein a particle size distribution of the phosphor particles is within ± 50% of an average particle size. A method for producing a vacuum ultraviolet ray-excited phosphor, comprising etching the surface of phosphor particles having an average particle diameter of 20 nm to 2 μm. In the manufacturing method of the vacuum ultraviolet-excited fluorescent substance of Claim 4,
A method for producing a vacuum ultraviolet-excited phosphor, wherein a particle size distribution of the phosphor particles is within ± 50% of an average particle size. A method for producing a vacuum ultraviolet ray-excited phosphor, comprising etching the surface of phosphor particles having a particle size distribution within ± 50% of an average particle size. In the manufacturing method of the vacuum ultraviolet-excited fluorescent substance as described in any one of Claims 1-6,
A method for producing a vacuum ultraviolet-excited phosphor, wherein the etching process is performed using a strong acid of 0.001N or more and less than 6N. In the manufacturing method of the vacuum ultraviolet ray excitation fluorescent substance according to claim 7,
A method for producing a vacuum ultraviolet-excited phosphor, wherein the etching treatment is performed using a strong acid of 0.001N or more and less than 2.5N. In the manufacturing method of the vacuum ultraviolet ray excitation fluorescent substance according to claim 7,
A method for producing a vacuum ultraviolet-excited phosphor, wherein the etching treatment is performed using a strong acid of 0.001N or more and less than 0.25N. A method for producing a vacuum ultraviolet-excited phosphor, comprising etching the surface of the phosphor particles using a strong acid of 0.001N or more and less than 0.25N. In the manufacturing method of the vacuum ultraviolet ray excitation fluorescent substance according to any one of claims 1 to 10,
The method for producing a vacuum ultraviolet-excited phosphor, wherein the amount of phosphor particles removed by the etching treatment is 1.5 mol% or more and less than 20 mol%. A method for producing a vacuum ultraviolet-excited phosphor, comprising etching the surface of the phosphor particles so as to remove an amount of 1.5 mol% or more and less than 20 mol%. In the manufacturing method of the vacuum ultraviolet-excited fluorescent substance as described in any one of Claims 1-12,
The method for producing a vacuum ultraviolet-excited phosphor, wherein the phosphor particles are Zn ₂ SiO ₄ : Mn ²⁺ . A vacuum ultraviolet-excited phosphor produced by the method for producing a vacuum ultraviolet-excited phosphor according to any one of claims 1 to 13. 15. A plasma display panel comprising the vacuum ultraviolet-excited phosphor according to claim 14 in a phosphor layer.

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