JP2001316664A - Fluorescent paste and member for display and display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluorescent paste for displays comprising an aluminate fluorescent substance prepared by activating bivalent europium, which allows little reduction in the luminous intensity and shift in the chromaticity in a paste-calcining step and yields a panel showing a high luminous brightness by improving the base composition, and a display. SOLUTION: The fluorescent paste for displays contains a fluorescent powder and a resin component, wherein the fluorescent powder comprises an aluminate fluorescent substance prepared by activating bivalent europium wherein aluminum elements are excessive against a stoichiometric composition. The member for displays and a display are formed using the fluorescent paste for displays.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a plasma display (hereinafter abbreviated as PDP), an electron-emitting device (field emission, FE) or a fluorescent display device (VF).
The present invention relates to a phosphor paste for a display which forms a phosphor layer of an image forming apparatus or the like using D).

[0002]

2. Description of the Related Art PDPs have attracted attention as displays that can be used for thin and large-size televisions. FIG. 1 shows an exploded perspective view of a structural example of a PDP. In a PDP, for example, a pair of sustain electrodes and scan electrodes are formed of a material such as silver, copper chromium, aluminum, nickel, and ITO on a glass substrate on a front plate side serving as a display surface. Further, a dielectric layer mainly composed of glass is formed by covering the sustain electrode and the scan electrode.
A gO layer is formed. On the other hand, a plurality of address electrodes are formed in a stripe shape on the glass substrate on the back plate side,
A dielectric layer is formed to cover the address electrodes. A partition for dividing discharge cells is formed on the dielectric layer, and a phosphor layer is formed in a discharge space formed by the partition and the dielectric layer. In a PDP capable of full-color display, the phosphor layer is formed of one that emits light of each color of RGB. The front plate and the back plate are sealed so that the sustain electrodes of the glass plate on the front plate side and the address electrodes on the back plate side are orthogonal to each other, and are formed of helium, neon, xenon, etc. in the gap between those substrates. A rare gas is sealed, and drive circuits such as a scan driver IC and an address data driver IC are mounted to form a PDP.
Since the pixel cell is formed around the intersection of the scan electrode and the address electrode, the PDP has a plurality of pixel cells,
Image display becomes possible.

When a display is performed on a PDP, when a voltage higher than a discharge starting voltage is applied between a sustain electrode and an address electrode in a selected pixel cell from a state where no light is emitted, cations and electrons generated by ionization are removed. Since the pixel cell is a capacitive load, it moves in the discharge space toward the electrode of the opposite polarity and is charged on the inner wall of the MgO layer, and the charge on the inner wall is not attenuated due to the high resistance of the MgO layer. It remains as wall charges.

Next, a sustaining voltage is applied between the scan electrode and the sustain electrode. Where there is a wall charge,
It is possible to discharge even at a voltage lower than the discharge starting voltage.
The xenon gas in the discharge space is excited by the discharge,
Ultraviolet light of 7 nm is generated, and the ultraviolet light excites the fluorescent substance, thereby enabling light emission display.

[0005] Such a phosphor layer of PDP is formed by arranging a paste containing phosphor particles excited and emitted by ultraviolet rays and a sheet-like paste on a panel substrate.
It is formed by firing at about 00 ° C. to burn off the organic binder component in the paste. In order to make PDP higher in display quality, it is desired to improve the emission intensity and emission efficiency of the phosphor layer. However, in the paste baking step, the emission intensity and the chromaticity shift of the blue phosphor using the aluminate phosphor activated with divalent europium are large, the panel emission luminance is decreased, and the white color temperature is decreased. This has been a problem as it has declined.

On the other hand, as an improvement of the phosphor particles themselves, JP-A-8-85787 discloses that by adding In to a divalent europium-activated aluminate phosphor, the phosphor of the aluminate phosphor is crystallized. In between the spinel blocks
Is present in a monovalent or divalent form, and it is shown that divalent europium is oxidized instead of oxidized during firing, thereby suppressing a decrease in emission intensity. Japanese Patent Application Laid-Open No. H8-143863 discloses that at least one of Sm, Tm and Yb is added between spinel blocks in the aluminate phosphor crystal by adding at least one of Sm, Tm and Yb. It has been shown that it exists in the form of a valence and similarly suppresses a decrease in emission intensity. Also, National Tec
In hnical Report Vol.43 No.2 Apr.1997, it is effective to suppress the generation of by-products in order to suppress the decrease in luminescence intensity due to firing, and to use a stoichiometric phosphor having good crystallinity. It has been shown that this can be achieved. Also,
JP-A-11-246856 discloses that a decrease in emission intensity is suppressed by limiting the activation amount of divalent europium to 8 atm% with respect to the barium element to be replaced.

On the other hand, as a method for improving the above problem with a phosphor paste, a specific methacrylate copolymer is used as an organic binder resin in Japanese Patent Application Laid-Open No. 10-324869 to obtain a fluorescent material by decomposition of organic substances. It has been shown to suppress structural changes in the body and prevent a reduction in brightness.

[0008]

However, even with these means, the effect of suppressing the decrease in emission intensity was still insufficient. The light emission of the aluminate phosphor is, for example, 1 in PDP.
This occurs when the host crystal absorbs the energy of the ultraviolet light of 47 nm, transmits the energy to the light-emitting ions serving as the light-emission center, excites the light, and emits light when the light-emission ions return from the light-emission level to the ground level. Therefore, not only changes in the luminescent ions themselves or in the vicinity thereof but also changes in the host crystal greatly affect the luminescence intensity. In other words, not only the deterioration of the phosphor particles themselves due to firing, but also the firing of the paste by other components of the paste or external elements, the defects in the base crystal and the increase in impurity elements cause the emission intensity of the phosphor layer to increase. As a result of the investigation, it was found that the matrix composition was a significant factor in the decrease in luminance of the phosphor particles themselves.

In view of the above, the present invention provides an aluminate phosphor activated with divalent europium, by improving the composition of the aluminate which is to be a base, so that the emission intensity in the firing step and the chromaticity shift are reduced. Another object of the present invention is to provide a display phosphor paste having a high panel light emission luminance, a display member using the paste, and a display.

[0010]

That is, the present invention relates to a phosphor paste containing a phosphor powder and a resin component.
A phosphor powder for a display, wherein the phosphor powder is an aluminate phosphor activated with divalent europium, and has a composition in which an aluminum element is excessive relative to a stoichiometric composition.

The present invention also provides a display member formed using the above-described phosphor paste for a display, and a display using the same.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below. First, the phosphor paste for a display of the present invention will be described. When the phosphor layer is formed on the PDP, the phosphor paste itself may be used in place of the phosphor paste itself.

The phosphor paste of the present invention contains phosphor powder and a resin component as essential components, and is dispersed and dissolved in a suitable solvent (such as an organic solvent). The contents of the phosphor powder and the resin component are preferably 70 to 95% by weight of the phosphor powder and 5 to 30% by weight of the resin component based on the phosphor paste in a dry state. More preferably, the phosphor powder is 80
-90% by weight, and the resin component is 10-20% by weight. If the amount of the resin component is too small, the dispersion stability of the phosphor powder in the paste, the viscosity and fluidity of the paste, the retention of the thickness of the coating film, and the like tend to be unobtainable. If the amount of the resin component is too large, the removal of the resin component by firing tends to be incomplete, resulting in a residue that tends to reduce the emission intensity, and it takes time to remove the organic component by firing, and the phosphor particles Deterioration of firing itself tends to increase.

The phosphor powder of the phosphor paste of the present invention comprises:
It is necessary that the aluminate phosphor be activated with divalent europium and that the aluminum element be in excess of the stoichiometric composition. After the phosphor powder is dispersed with a resin component and a solvent or the like into a paste by making the aluminum element excessive with respect to the stoichiometric composition, firing is performed in the air to burn off the organic binder component such as the resin component. The decrease in emission intensity caused by the above is suppressed. This decrease in luminous intensity was caused by activation of aluminate by 2
It is presumed that trivalent valent is oxidized by baking in the atmosphere to become trivalent, and the aluminate host crystal absorbs ultraviolet rays, does not emit the transmitted energy, and transitions to the ground state without radiation. Have been. In addition, when the paste is baked, the luminescence intensity is greatly reduced as compared with the case where only the powder is baked.
It is presumed that absorption and energy transfer at around 47 nm are reduced. Since the aluminate phosphor powder activated with divalent europium is prepared in a reducing atmosphere as described later, it is considered that oxygen is insufficient for the stoichiometric composition, that is, oxygen deficiency is likely to occur. When oxygen deficiency occurs, a trap level is formed, so that the probability of transition to the ground state without light emission increases, so that not only the emission intensity tends to decrease, but also oxygen deficient due to baking in the air or baking paste. Easily penetrates into the inside of the mother body, and divalent europium is easily oxidized to trivalent. In addition, when oxygen deficiency occurs, the lattice constant increases due to electrostatic repulsion of metal cations, and the heat resistance of the host crystal tends to deteriorate. Since the phosphor paste of the present invention has a composition in which the aluminum element is excessive relative to the stoichiometric composition, the content of oxygen after preparing the phosphor powder is large, that is, the amount of oxygen deficiency is small,
In particular, the surface layer of the phosphor powder to be a light emitting region (about 100
It is estimated that thermal degradation and oxidation of divalent europium due to paste baking of the host crystal (up to nm) are suppressed.

The excess amount of the aluminum element is preferably 10% or less based on the stoichiometric composition. If the excess amount is more than 10%, a single phase is not formed during the synthesis of the phosphor powder, and a by-product is generated, the emission value is reduced, the y value of the chromaticity is increased, and the color purity of blue is reduced. Tends to have a narrower color reproducibility range. Preferably, it is in the range of 0.1 to 9.5% based on the stoichiometric composition. More preferably, it is in the range of 1 to 9%, and further preferably, it is in the range of 2 to 8%.

As the aluminate having a stoichiometric composition, for example, MMgAl ₁₄ O ₂₃ , MMgAl ₁₀ O ₁₇ , MMg ₂
Al ₁₆ O ₂₇ , MMg ₂ Al ₁₄ O ₂₄ , M ₂ Mg ₂ Al ₁₂ O
_22, M _3, etc. _{Mg 4 Al 8 O 18, M} 3 Mg 5 Al 18 O 25 and the like. Although the aluminate phosphor actually created tends to have less oxygen than the stoichiometric composition,
Here, the stoichiometric composition formula was used. M preferably comprises at least one of Ba, Sr and Ca. Preferably, the MMgAl ₁₀ O ₁₇ atomic aluminate may reduce the emission intensity and reduce the chromaticity shift during panel lighting.

It is preferable that the amount of magnesium is 90 to 100% based on the stoichiometric composition. When the magnesium element is within this range, the heat resistance of the host crystal is improved, and the deterioration of luminance during paste firing tends to be suppressed. When the magnesium element is less than 90% or more than 100%, the luminance degradation due to paste firing tends to increase.

It is preferable that the substitution amount of divalent europium is in the range of 5 to 20 atm% with respect to the M element.
If the substitution amount is less than 5 atm%, an electron trap having a deep energy level near divalent europium is formed by irradiation with ultraviolet light when the panel is lit, and the emission intensity may decrease and the chromaticity shift may increase. . Replacement amount is 2
If it exceeds 0 atm%, the emission intensity may decrease due to firing and the chromaticity deviation may increase.
At tm% or more, the luminescence intensity tends to decrease to the unfired phosphor powder due to concentration quenching.

The phosphor powder can be synthesized, for example, by the following method. As a phosphor material, barium oxide, barium hydroxide, barium compounds such as barium carbonate, strontium oxide, strontium hydroxide, strontium compounds such as strontium carbonate, calcium oxide, calcium hydroxide, calcium compounds such as calcium carbonate, europium oxide, Europium compounds such as europium fluoride, magnesium oxide, magnesium hydroxide, magnesium compounds such as magnesium carbonate, aluminum oxide,
A predetermined amount of an aluminum compound such as aluminum hydroxide is mixed and weighed, and fluxes such as barium fluoride, aluminum fluoride and magnesium fluoride are blended, and the raw material mixture is sufficiently mixed with a ball mill or the like. The obtained mixture is filled in a crucible and is usually heated at a temperature of 1400 ° C. to 1650 ° C. in a reducing atmosphere such as nitrogen or nitrogen-hydrogen at 2 to 4 ° C.
Bake at least once over 0 hours. Preferably, firing is performed twice or more. By firing in a reducing atmosphere, europium is reduced from trivalent to divalent. Disperse, wash,
After drying and classification, the aluminate phosphor activated with divalent europium used in the present invention can be obtained.
Further, in order to improve dispersibility in the phosphor paste and to suppress a decrease in emission intensity due to baking, a surface treatment of coating the surface of the phosphor particle powder with an inorganic substance or an organic substance may be performed.

The particle diameter of the phosphor powder is such that the cumulative average particle diameter D50 measured by a laser diffraction scattering method (for example, wet measurement using an HRA particle size distribution analyzer manufactured by Microtrac) is 0.
It is preferably in the range of 5 to 10 μm, more preferably in the range of 1 to 5 μm. By controlling the average particle diameter to 0.5 μm or more, the cohesiveness of the powder is suppressed, the paste coatability is improved, and the denseness and homogeneity of the coating film and the phosphor layer after firing are improved. can do. When the thickness is 10 μm or less, unevenness on the surface of the phosphor layer after firing can be suppressed, and a decrease in luminance and a variation in luminance due to irregular reflection of light emission can be further prevented.

The maximum particle size of the phosphor powder is 40 μm.
Hereinafter, it is more preferable that the thickness be 20 μm or less. By setting the maximum particle size to 40 μm or less, unevenness of the phosphor layer after firing can be further suppressed. Further, it is preferable that the thickness be 20 μm or less in terms of powder filling properties. Also, the maximum particle size is related to the method of applying the phosphor paste, and in the case of the screen printing method, it is related to the aperture ratio of the mesh, and is related to the nozzle diameter such as the nozzle discharge method. That is important. As a shape of the phosphor powder, a powder having a shape close to a sphere can be more preferably used from the viewpoint of suppressing aggregation.

The specific surface area of the phosphor powder depends on the particle diameter and particle shape, but is preferably 1.2 to 4.0 m ² / g. When the thickness is 1.2 m ² / g or more, the particles are not coarsened, the paste coating film is made dense, and the unevenness of the phosphor layer surface can be further suppressed. By setting the specific surface area to 4.0 m ² / g or less, the particles are not too fine and aggregation can be further suppressed.

The tap density of the phosphor powder is set to 0.6 g.
/ Cm ³ or more, more preferably 0.7 g / cm ³ or more. Tap density refers to JIS Z2500 (2
045) is the mass per unit volume of the powder in the vibrated container. Tap density of 0.6g / cm
^{When the} ratio is ³ or more, the filling and dispersibility of the powder into the paste are improved, and bubbles and aggregates are less likely to be generated, thereby contributing to the formation of a denser and more uniform coating film. In addition, the binder can be removed smoothly, the firing time of the phosphor layer can be shortened, and the decrease in emission intensity can be further suppressed.

The resin component of the phosphor paste of the present invention is usually 400 to 500 with little deterioration of the emission intensity of the phosphor powder.
Thermoplastic resin fired at a relatively low temperature of about ° C. is preferable, and as a resin component that can be fired at such a low temperature, methylcellulose, ethylcellulose, propylcellulose, hydroxymethylcellulose, hydroxylethylcellulose, hydroxylpropylcellulose, hydroxylethylpropylcellulose and the like Cellulosic resins and polymethyl methacrylate, poly-i-propyl methacrylate, poly-i-butyl methacrylate and, if necessary, methyl (meth) acrylate, ethyl ( (Meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, benzyl (meth) acryle DOO, dimethylaminoethyl (meth) acrylate, hydroxyl ethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxyl butyl (meth) acrylate, phenoxy -
An acrylic resin obtained by copolymerizing an acrylic monomer such as 2-hydroxypropyl (meth) acrylate or glycidyl (meth) acrylate can be used.

The solvent of the phosphor paste of the present invention may be any organic solvent which does not separate from the resin component, and may be alcohols,
Ethers, esters, and the like, and mixtures thereof are preferred. In particular, it is preferable to use terpineol (terpineol) because it dissolves the binder resin well, sufficiently disperses the phosphor powder, and has excellent coatability. Commercial terpineol is a mixture of three isomers and is a liquid with a boiling point of 217-219 ° C. Further, in order to adjust the viscosity of the phosphor paste, it is preferable to mix terpineol with an aromatic alcohol having a similar boiling point, for example, benzyl alcohol.

When the phosphor paste of the present invention is formed by a photolithography method, a compound containing a carbon-carbon unsaturated bond as a photosensitive monomer, a photopolymerization initiator such as benzophenone, and a photopolymerization initiator for imparting photosensitivity. An organic dye such as Sudan 4 for suppressing light scattering may be contained.

The phosphor paste of the present invention may further comprise an organic compound dispersant such as an anionic or nonionic surfactant, a higher aliphatic alcohol, and a plasticizer (for example, dibutyl phthalate, dioctyl phthalate). , Polyethylene glycol, glycer, etc.).

The phosphor paste of the present invention is prepared by dissolving a binder resin in a solvent by heating with a stirrer (usually at about 80 ° C.), and adding phosphor powder to, for example, a three-roll or ball mill. Can be manufactured by kneading using a dispersing machine.

Next, a display member using the phosphor paste of the present invention and a PDP as an example of a display will be described in accordance with a manufacturing procedure. However, the present invention is not particularly limited thereto, and an electron-emitting device (field emission, FE) or a fluorescent material is used. It can be preferably applied to an image forming apparatus using a display tube element (VFD).

(Back Plate) As a substrate used for a back plate as a member for PDP of the present invention, besides soda glass, PD
As the heat-resistant glass for P, "PD200" manufactured by Asahi Glass Co., Ltd. or "PP8" manufactured by NEC Corporation can be used.

An address electrode is formed in a stripe shape at a pitch of a discharge cell on a glass substrate by using a metal such as silver, aluminum, chromium or nickel. As a method of forming, a method of pattern-printing a metal paste containing these metal powders and an organic binder as main components by screen printing, or after applying a photosensitive metal paste using a photosensitive organic component as an organic binder, A photosensitive paste method in which pattern exposure is performed using a photomask, unnecessary portions are dissolved and removed in a developing step, and further, heating and baking at 400 to 600 ° C. to form a metal pattern can be used. In addition, an etching method is used in which a metal such as chromium or aluminum is deposited on a glass substrate, a resist is applied, and the resist is subjected to pattern exposure and development using a photomask and then etched to remove unnecessary metal. Can be.

The electrode thickness is preferably 1 to 10 μm,
5 μm is more preferred. If the electrode thickness is too thin, the resistance value tends to be large and accurate driving tends to be difficult, and the power consumption also increases.If the electrode thickness is too thick, many materials are required,
It tends to be disadvantageous in terms of cost. If the width of the address electrode is too small, the resistance value tends to be high and accurate driving tends to be difficult.If the width is too large, the distance between adjacent electrodes is short.
Short defects tend to occur. Further, the address electrodes are formed at a pitch corresponding to the display cell (the area where each RGB of a pixel is formed). 100 ~
500 μm, 100-250 μm for high-definition PDP
It is preferable to form at a pitch of m.

Further, a dielectric layer may be provided on the address electrode layer for stabilizing discharge.

On a glass substrate on which an address electrode layer is formed, partition walls located in parallel with the electrode layer are formed by a sandblast method,
It is formed by a mold transfer method, a photolithography method, or the like. The material of the partition used in the present invention is not particularly limited, and a glass material containing an oxide of silicon and boron is applied. In addition, it is advantageous when formed by a photolithography method that 70% by weight or more of a glass material having a refractive index of 1.5 to 1.68 is included.

A phosphor layer is formed on a glass substrate on which an electrode layer and a partition layer are formed by a photolithography method using a photosensitive phosphor paste, a dispenser method, a screen printing method, or the like. The red and green phosphor materials used in the present invention are not particularly limited, and phosphor powder is used. For example, in red, Y ₂ O ₃ : Eu, YVO ₄ : E
u, (Y, Gd) BO ₃ : Eu, Y ₂ O ₃ S: Eu, γ-
There is Zn ₃ (PO ₄ ) ₂ : Mn. In green, Zn ₂ GeO
₂ : Mn, BaAl ₁₂ O ₁₉ : Mn, Zn ₂ SiO ₄ : M
n, LaPO ₄ : Tb, ZnS: Cu, Al, Zn ₂ Si
O ₄ : Mn, As, (ZnCd) S: Cu, Al, Zn
O: Zn and the like. For blue, an aluminate phosphor activated with divalent europium having a composition in which the aluminum element is excessive relative to the stoichiometric composition of the present invention is used. In this way, a back plate can be manufactured.

(Front Plate) The glass substrate used for the front plate is the same as that described for the back plate.

On a glass substrate, a transparent electrode such as tin oxide or ITO is formed by a lift-off method, a photo-etching method, or the like.

On a glass substrate on which a transparent electrode is formed, a bus electrode layer is formed by patterning silver, aluminum, copper, gold, nickel, or the like by screen printing or photolithography using a photosensitive conductive paste.

A transparent dielectric layer is formed on a glass substrate on which a transparent electrode and a bus electrode are formed by a screen printing method or the like. The transparent dielectric material used in the present invention is not particularly limited, but a dielectric material containing PbO, B ₂ O ₃ , and SiO ₂ is applied.

Further, for the purpose of protecting the transparent dielectric layer and lowering the discharge voltage, a protective film is formed so as to cover the transparent dielectric layer. Generally, an oxide of an alkaline earth metal can be used for the protective film. In particular, MgO has excellent spatter resistance,
It is preferably applied because the secondary electron emission coefficient is high. M
The gO protective film is formed by an electron beam evaporation method, a reactive sputtering method of a Mg target, or an ion plating method. In this way, a front plate can be manufactured.

(Plasma Display) After sealing the back plate and the front plate by using the back plate and the front plate of these members for plasma display, helium, neon, xenon, etc. After injecting a discharge gas composed of, a plasma display can be manufactured by mounting a drive circuit.

[0042]

The present invention will be specifically described below with reference to examples. However, the present invention is not limited to this.

(Measurement Method) (1) Particle Size Distribution The particle size distribution of the phosphor powder was measured using a particle size distribution analyzer (Microtrac HRA particle size analyzer “MODEL No. 9320-X100”) utilizing a laser diffraction scattering method. Measured. The measurement conditions were as follows. Sample amount: 1 g Dispersion conditions: Ultrasonic dispersion in purified water for 1.5 minutes. If dispersion is difficult, perform in 0.2% sodium hexametaphosphate aqueous solution. Particle refractive index: 1.77 Solvent refractive index: 1.33 Number of measurements: 2 times (2) Tap density Tap density was determined by A. Tsutsui Chemical Co., Ltd. B. Using a D powder property measuring instrument, the 100 cc container containing the powder was vibrated for 5 minutes, and then the powder was rubbed and the powder mass per 100 cc was measured and calculated.

(3) Composition Analysis In the composition analysis of Ba, Mg, Al and Eu, about 0.1 g of the phosphor powder was melted with sodium carbonate and boric acid, dissolved by heating with pure water, and then acidified with nitric acid. After adjusting the volume to constant volume with water and diluting this solution with dilute nitric acid, a sequential ICP emission spectrometer (SPS) manufactured by Seiko Instruments Inc.
4000), the content of each element was determined, and the relative value was calculated.

(4) Oxygen Content The oxygen content was determined by drying the phosphor powder at 150 ° C. for 1 hour.
About 10 mg of the phosphor powder was weighed, melted in an inert gas, and determined from the amount of infrared absorption of the generated gas. The oxygen content was represented by the ratio between the weight of the phosphor powder before melting and the weight of oxygen calculated from the amount of infrared absorption. For analysis, EMGA-650 manufactured by Horiba, Ltd. was used.

(5) Emission Characteristics of Phosphor The emission intensity (energy) and chromaticity, which are the emission characteristics of the phosphor, were measured as follows. Approximately 600 mg of the phosphor powder is placed on a SUS dish (sample holder) having a diameter of 24 mm and a depth of 1 mm, and pressed against a glass plate to flatten it. This sample was placed in a chamber, and the inside of the chamber was once evacuated to 5 Pa or less with a rotary pump.
Flowing nitrogen gas having a purity of 99.9% or more at a flow rate of ^-3 / min;
After leaving for 30 minutes, the inside of the chamber is replaced with nitrogen gas.
Then, Ushio's excimer light emitting lamp H0012
146 nm ultraviolet light from an excimer light irradiator with a built-in
Irradiate from 5 cm away. The emission intensity and the chromaticity were measured from 23 cm directly above the sample surface using an instantaneous multiphotometry system MCPD-2000 manufactured by Otsuka Electronics Co., Ltd.

On the other hand, the sample for measuring the light emission characteristics after the paste was fired was a coating film formed by forming a phosphor paste on a glass substrate to a dry thickness of 30 μm using a screen printing method (screen plate: SUS # 200). Is dried in an oven at 80 ° C. for 30 minutes, and then placed in a firing furnace,
The material baked at 00 ° C. for 15 minutes was scraped and placed in the same sample holder as above to measure.

The luminescence retention rate is calculated by Is / Ip × (Ip / Ip × Ip) where (Ip) is the integrated value (energy) of the spectrum of the luminescence intensity of the phosphor powder and (Is) the luminescence energy of the phosphor powder after firing into a phosphor paste. It is shown by 100 (%).

(6) Light-Emitting Characteristics of the Panel The luminance and the color temperature of the panel were fully lit under the discharge conditions of a discharge sustaining voltage of 170 V, a frequency of 30 kHz, and a pulse width of 3 μm, and a spectral radiance meter CS-1000 manufactured by Minolta was used. Measured.

(Examples 1 to 5, Comparative Examples 1 to 3) Raw materials of barium carbonate, europium oxide, basic magnesium carbonate trihydrate and γ-alumina were weighed according to the composition, and aluminum fluoride as a flux was measured. Several percent mol was added to the alumina atoms of the raw material γ-alumina, and the mixture was sufficiently mixed by a ball mill. Then, in a reducing atmosphere of a mixture of nitrogen and hydrogen (5%), the maximum temperature was 1450 ° C.
The primary firing was performed over 2 hours. Next, crush the baked ingredients,
Classification was performed and secondary firing was performed again under the same conditions as above. next,
The baked components were classified, washed, dried, and sorted to obtain an aluminate phosphor activated with divalent europium in which the aluminum element was excessive in stoichiometric composition.

Next, 80 parts by weight of the phosphor powder, 18 parts by weight of ethyl cellulose resin as a binder resin,
After dissolving 10 parts by weight of terpineol and 70 parts by weight of benzyl alcohol as solvents, the mixture was dispersed with three rollers to obtain a phosphor paste. These properties are shown in Tables 1 and 2.
Table 3 shows the results of oxygen analysis after firing the unsintered phosphor, firing at 500 ° C. in air, and firing the paste.

[0052]

[Table 1]

[0053]

[Table 2]

[0054]

[Table 3]

As can be seen from the results in Table 1, Examples 1 to 3 have higher emission retention rates after paste baking of 90% or more than those of Comparative Examples 1 and 2, so that the emission intensity is higher by 10% or more. This is a good result. Further, the chromaticity y value is small, the bluish color is deep, and the color reproducibility range can be widened when the panel is formed.

This is because, as shown in Table 3, by increasing the amount of aluminum, the oxygen content in the host crystal is increased,
Further, it is considered that the change in the oxygen content during firing in the atmosphere or firing of the paste is small.

Looking at the results in Table 2, Examples 4 and 5 show that E
When the amount of added u increases, the emission intensity degradation due to firing increases, but the emission retention ratio after the paste firing in Comparative Example 3 is improved to 80% or more, and the emission intensity is increased by 35% or more. This is a good result.

Examples 6 and 7, Comparative Example 4 A phosphor paste was obtained in the same manner as in Examples 2, 3 and Comparative Example 2 except that the binder resin was changed to polymethyl methacrylate. 4).

[0059]

[Table 4]

As can be seen from the results in Table 4, Examples 6 and 7 have a high luminescence retention rate after the paste sintering of 98% or more, and the luminescence intensity is 10% or more higher than that of Comparative Example 4, which is a good result. Further, the chromaticity y value is small, the bluish color is deep, and the color reproducibility range can be widened when the panel is formed.

Example 8 First, a front plate was manufactured. Asahi Glass Company's "PD200" on a 3-inch glass substrate
A scan electrode having a pitch of 1290 μm and a line width of 470 μm was formed using O. A bus electrode having an electrode width of 120 μm and a thickness of 3 μm was formed on the substrate by a photosensitive silver paste method. Next, a transparent dielectric glass paste is screen-printed so as to cover the bus electrodes in the display area.
A front dielectric was formed with a thickness of 0 μm. A 0.5 μm-thick magnesium oxide layer was formed as a protective film on the substrate on which the dielectric was formed by electron beam evaporation to produce a front plate.

Next, a back plate was manufactured. “PD200”
Using photosensitive silver paste on a 3 inch glass substrate, width 2
Address electrodes having a thickness of 00 μm, a thickness of 3 μm, and a pitch of 430 μm were formed. Next, a dielectric layer having a thickness of 20 μm was formed by a screen printing method. Next, by photolithography using a photosensitive partition paste, the width is 60 μm and the height is 12 μm.
A 0 μm partition was formed. Next, a phosphor layer was formed on the partition wall by a dispenser method using a nozzle having one outlet having a hole diameter of 150 μm so that both the partition bottom and the side had a thickness of about 20 μm. The red and green phosphor pastes are prepared by adding red: (Y, Gd, Eu) BO3 and green: (Zn, Mn) ₂ S to the phosphor powder.
An iO ₄ composition was used, and the one produced in the same manner as the blue phosphor paste of the present invention of Example 3 was used. Thus, a back plate was produced.

The front plate and the back plate are aligned so that matrix display driving can be performed, sealed with a glass frit for sealing, evacuated while heating to 350 ° C., and then Xe 5% −
A plasma display was produced by filling Ne gas at 67 kPa.

The light emission characteristics of this panel were such that the initial luminance was 80.
0 cd / m ² , color temperature 7000 K, brightness of blue phosphor higher than Comparative Example 5, color temperature 1000 K higher, color TV
When the color temperature required for the image is adjusted to 9500K or more, the decrease in luminance is as small as about 10%.

Comparative Example 5 A panel was obtained in the same manner as in Example 8, except that the blue phosphor paste used in Comparative Example 1 was used. The light emission characteristics of this panel are such that the initial luminance is 750 cd /
When the color temperature is adjusted to 9500 K or more, which is required for a color TV image, at m ² and a color temperature of 6000 K, the luminance of the blue phosphor is low, and the luminance decrease is as large as about 40%.

[0066]

According to the present invention, in the aluminate phosphor activated with divalent Iupium, the base composition is improved to reduce the emission intensity and the chromaticity in the paste firing step, and to reduce the panel light emission. It is possible to provide a display phosphor paste having high brightness, a display member using the paste, and a display.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a plasma display.

[Explanation of symbols]

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ichiharu Shimizu 1-1-1, Sonoyama, Otsu-shi, Shiga Prefecture Toray Industries, Inc. Shiga Plant (72) Inventor Noboru Kawabata 1-1-1, Sonoyama, Otsu-shi, Shiga Prefecture No. Toray Corporation Shiga Plant

Claims (9)

[Claims] 1. A phosphor paste containing a phosphor powder and a resin component, wherein the phosphor powder is a divalent europium-activated aluminate phosphor, and an aluminum element relative to the stoichiometric composition. Has an excessive composition. 2. The method according to claim 1, wherein the excess amount of the aluminum element is not more than 10% with respect to the stoichiometric composition.
The phosphor paste for a display according to 1. 3. The stoichiometric composition of the aluminate is MMgA.
l ₁₀ is O _17, and M is at least Ba, claim 1 or 2 in the display for phosphor paste according to characterized in that it consists of at least one of Sr and Ca. 4. The method according to claim 3, wherein the amount of the magnesium element is 90 to 100% with respect to the stoichiometric composition.
The phosphor paste for display according to the above. 5. The amount of substitution of divalent europium is 5 to 20 atm% with respect to M element.
Or the phosphor paste for a display according to 4. 6. The phosphor paste for a display according to claim 1, wherein the resin component is a cellulose resin or an acrylic resin. 7. The display according to claim 1, wherein the display is an image forming apparatus using a plasma display panel, an electron-emitting device, or an image forming device using a fluorescent display tube element. Phosphor paste for display. 8. A display member formed by using the phosphor paste for a display according to claim 1. Description: 9. A display comprising the display member according to claim 8.