JPH1143670A - Colored phosphor particle, and composition for forming phosphor layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain particles which can form a phosphor layer reduced in outdoor daylight reflectance and improved in contrast by fusing a pigment to coat phosphor particles. SOLUTION: The mean particle diameter of the pigment is preferably at most equal to the mean diameter of phosphor particles. It is desirable that the amount of the pigment fused to coat the phosphor is 0.1-50 wt.%. The pigment preferably has the same type of color as the luminescent color of the phosphor particles. The use of a black pigment can give a colored phosphor excellent in the effect of reducing the outdoor daylight reflectance. The colored phosphor particles can realize the control of the color forming properties and outdoor daylight reflectance of a phosphor by the thickness of a film of the pigment, so that they can be suitable for use, for example, for a phosphor layer of, e.g. a plasma display panel wherein the fluorescent color formed is observed under outdoor daylight. The composition for forming the phosphor layer consists of the colored phosphor particles, a resin removable by burning, and a solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is suitable for forming a phosphor layer in a plasma display panel (hereinafter, PDP), a fluorescent display tube, a cathode ray tube, a cathode ray tube, etc., which is a self-luminous type flat display using gas discharge. Colored phosphor particles and a composition for forming a phosphor layer.

[0002]

2. Description of the Related Art Regarding a phosphor layer to which the present invention is applied,
A description will be given using PDP as an example. AC type (AC) for PDP
There are two types, a direct current type (DC) type and an AC type PDP. For example, as shown in FIG. 1, two glass substrates 1 and 2 are arranged in parallel and opposed to each other. Are held at regular intervals by cell barriers 3 provided in parallel on a glass substrate 2 serving as a back plate. On the back side of the glass substrate 1 serving as the front plate, a composite electrode composed of a transparent electrode 4 serving as a discharge sustaining electrode and a metal electrode 5 serving as a bus electrode is formed in parallel with each other. Layer 6
Is formed thereon, and a protective layer (MgO layer) is further formed thereon.
Are formed. In addition, address electrodes 8 are formed on the front side of the glass substrate 2 serving as the back plate and between the cell barriers 3 so as to be perpendicular to the composite electrode with the address electrodes 8 formed in parallel with each other. A phosphor layer 9 is provided so as to cover the wall surface and the cell bottom.

Further, as shown in FIG. 2, after forming a base layer 10 on a glass substrate 2 serving as a back plate, address electrodes 8 and
In some cases, the dielectric layer 6 ', the cell barrier 3, and the phosphor layer 9 are sequentially provided.

The AC type PDP is of a surface discharge type and has a structure in which a gas mainly composed of Ne or the like is sealed between both substrates, and an AC voltage is applied between composite electrodes on a front plate, This is a structure that discharges by the electric field leaked into the space. In this case, since the alternating current is applied, the direction of the electric field changes according to the frequency. Then, the phosphor layer 9 is caused to emit light by the ultraviolet light generated by the discharge, and the light transmitted through the front plate can be visually recognized by an observer. It should be noted that the DC type PDP is different in that the electrodes have a structure not covered with a dielectric layer, but the discharge phenomenon is the same. DC type,
Both AC types are classified into a refresh drive system and a memory drive system according to differences in display functions and drive methods.

Conventionally, the phosphor used in such a PDP or a cathode ray tube has a high external light reflectance because the phosphor itself is white, and causes a decrease in contrast even when the phosphor is colored. It has become. Therefore, as a method of lowering the external light reflectance, a black matrix is formed or neodymium oxide (Nd ₂
A method using O ₃ glass, an ND filter, and a color filter, and a method of coloring the phosphor layer itself have been adopted.

[0006] The method of reducing the external light reflectance by the colored phosphor layer has advantages such as low cost and simple process as compared with other methods. Is simply mixed, the pigment and the phosphor particles are separated from each other, so that the pigment has a low covering effect and a sufficient effect of reducing the external light reflectance cannot be obtained. Also,
Increasing the amount of the pigment added to increase the coating effect of the pigment increases the covering power on the phosphor particles, but conversely reduces the color intensity of the phosphor and causes a decrease in contrast. There is a limit to the adjustment by the amount of addition.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to solve such a problem, and it is an object of the present invention to reduce the external light reflectance and to form a phosphor layer having an improved contrast. An object of the present invention is to provide phosphor particles and a composition for forming a phosphor layer.

[0008]

Means for Solving the Problems The colored phosphor particles of the present invention are characterized in that a pigment is fused and coated on the surface of the phosphor particles.

The average particle size of the pigment is not more than the average particle size of the phosphor particles, and the fusion and coating amount of the pigment is 0.1% by weight to 50% by weight based on the phosphor particles. It is characterized by being.

[0010] Further, the present invention is characterized in that the pigment has the same color as the emission color of the phosphor particles.

[0011] Alternatively, the colored phosphor particles according to claim 2.

Further, the present invention is characterized in that the pigment is a black pigment.

Further, the composition for forming a phosphor layer of the present invention comprises:
It is characterized by comprising colored phosphor particles having a pigment fused and coated on the surface thereof, a resin and a solvent which can be removed by firing.

[0014] The phosphor layer is a phosphor layer in a plasma display panel.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The colored phosphor particles of the present invention will be described. The colored phosphor particles fuse the pigment on its surface.
It is coated.

The phosphor particles emit light when excited by ultraviolet light. For example, those having a red emission color include Y ₂ O ₃ : Eu, YVO ₄ : Eu, and Y ₂ Si.
O ₅ : Eu, Y ₃ Al ₅ O ₁₂ : Eu, γ-Zn ₃ (PO
₄ ) ₂ : Mn, YBO ₃ : Eu, (Y, Gd) BO ₃ :
Eu, ScBO ₃ : Eu, LuBO ₃ : Eu, etc. are exemplified, and Y ₂ O ₃ S: Eu, (Zn, Cd) S: Ag
+ In ₂ O _{3 and the} like.

The emission color of green is Zn ₂ Ge
O ₂ : Mn, Zn ₂ SiO ₄ : Mn, Zn ₂ SiO ₄ :
Mn, As, BaAl ₁₂ O ₁₉ : Mn, SrAl ₁₃ O ₁₉ :
Mn, CaAl ₁₂ O ₁₉ : Mn, YBO ₃ : Tb, BaM
gAl ₁₄ O ₂₃ : Mn, BaAl ₁₂ O ₁₉ : Mn, LuBO
_{3: Tb, LaPO 4: Tb} , GdBO 3: Tb, Sc
BO ₃ : Tb, Sr ₆ Si ₃ O ₃ Cl ₄ : Eu, etc. are exemplified, and ZnS: Cu, Al, ZnS: Au, C
u, Al, (Zn, Cd) S: Cu, Al, Y ₃ Al ₅
O ₁₂ : Ce, Gd ₂ O ₂ S: Tb, Y ₃ Al ₅ O ₁₂ : T
b, ZnO: Zn and the like.

The emission color of blue is Sr ₅ (P
O ₄ ) ₃ Cl: Eu, Y ₂ SiO ₅ : Ce, Y ₂ SiO
₃ : Ce, CaWO ₄ : Pb, BaMgAl ₁₄ O ₂₃ : E
u ²⁺ , BaMgAl ₁₆ O ₂₇ : Eu and the like are exemplified.

When the phosphor particles are spherical, the average particle diameter is 0.1 μm to 15 μm, preferably 0.5 μm to 8 μm. The phosphor particles may have a shape other than a spherical shape, for example, a flat plate shape.

The pigment fused and coated on the surface of the phosphor particles may be any pigment having a heat resistance higher than the temperature at the time of firing during the process of manufacturing a substrate such as a PDP. Cadmium selenide, red iron oxide (Fe ₂ O ₃ ), cuprous oxide, cadmium mercury red (CdS + HgS), chrome vermillion, silver vermilion, antimony red, iodine red, zinc iron red, molybdenum red, lead tin, cadmium red, etc. Examples of green pigments include chrome green,
Zinc green, cobalt green, chromium oxide and the like,
Blue pigments include emerald green, ultramarine, navy blue,
Cobalt blue, cerulean blue, copper sulfide and the like can be mentioned, and as the black pigment, titanium black, black iron oxide (Fe ₃ O ₄ ) and the like can be mentioned. Further, composite oxide pigments (Cr, Co, Ni, Fe, Mn, Cu, Sb, A
s, Bi, Ti, Cd, Al, Ca, Si, Mg, Ba
And pigments comprising two or more kinds of metal oxides.

The color developing properties of the phosphor particles and the coloring of the pigment in the colored phosphor particles are preferably made to have the same color system from the viewpoint of improving the contrast. It is preferable to use a blue pigment in the case of coloring in green, and a green pigment in the case of coloring in green. When a black pigment is used, the effect of reducing the external light reflectance can be excellent.

Fusion of a coloring pigment to the surface of the phosphor particles
Examples of the coating method include a mechanofusion system (manufactured by Hosokawa Micron), a hybridization system (manufactured by Nara Machinery Co., Ltd.), and a kryptron system “KO”.
SMOS "(manufactured by Kawasaki Heavy Industries, Ltd.) and a super hybrid mill (manufactured by Ishikawa Harima Heavy Industries, Ltd.) are used. These devices are generally used for surface modification and particle shape control of particles, but in the present invention, these devices are used to coat pigment around phosphor particles to form coated composite particles. It is to make it. In these apparatuses, by adjusting the particle size of the pigment used for coating, a coating form in which the surface is smooth and a dense film can be formed, and a coating form in which the pigment is fused around the phosphor particles. Can also be.

The average particle size of the pigment particles fused and coated on the phosphor particles is preferably equal to or less than the average particle size of the phosphor particles, more preferably 0.01 μm to 3 μm, and if it exceeds 3 μm, the emission of the phosphor is inhibited. And it is not preferable.
If it is less than 01 μm, the coloring effect is reduced, and the external light reflectance cannot be reduced. The amount of fusion and coating of the pigment is in the range of 0.1% by weight to 50% by weight, preferably 0.5% by weight to 30% by weight with respect to the phosphor. It is preferable to fuse and coat as appropriate, and if it exceeds 50% by weight, it is not preferable because the light emission of the phosphor is inhibited, and if it is less than 0.1% by weight, there is no coloring effect, and external light reflection It is not preferable because the rate decreases. The degree of the coating of the phosphor particles with the pigment can be controlled in the above-described particle composite apparatus.

The colored phosphor particles having the pigment fused and coated on the surface as described above have an average particle size of 0.1 μm to 15 μm.
m, preferably 0.5 μm to 8 μm.

Since the colored phosphor particles of the present invention are obtained by fusing and coating a pigment on the surface of the phosphor particles, it is possible to control the color developing property and external light reflectivity of the phosphor by the thickness of the pigment. For example, it can be suitable for use in a phosphor layer in a PDP or the like in which fluorescence emission is observed under external light.

Next, the composition for forming a phosphor layer of the present invention comprises:
It consists of colored phosphor particles, a resin and a solvent which are removed by firing. The resin removed by firing is a binder, and examples thereof include a thermoplastic resin and a photosensitive resin.

Thermoplastic resins include, for example, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-propyl acrylate, n-propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, sec-butyl acrylate, sec-butyl methacrylate, n-butyl Methacrylate, n-butyl acrylate, isobutyl acrylate, isobutyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, n-
Pentyl acrylate, n-pentyl methacrylate,
n-hexyl acrylate, n-hexyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, n-octyl acrylate, n-
Octyl methacrylate, n-decyl acrylate, n
-A polymer or copolymer consisting of one or more of decyl methacrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, styrene, α-methylstyrene, N-vinyl-2-pyrrolidone,
Examples include cellulose derivatives such as ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, and carboxymethyl cellulose. Further, polyvinyl alcohol which is a water-soluble resin,
Poly-N-vinylpyrrolidone, casein and the like can also be used.

The thermoplastic resin is used in an amount of 0.5 to 30 parts by weight, preferably 1 to 30 parts by weight, based on 100 parts by weight of the colored phosphor particles.
The ratio may be from 20 parts by weight to 20 parts by weight. If the proportion of the thermoplastic resin is less than 0.5 part by weight, the retention of the phosphor layer is low, and if it is more than 30 parts by weight, carbon remains in the film after firing, and the quality is unfavorably reduced. Further, when the phosphor layer is patterned by sandblasting, the sandblasting property is reduced.

Further, a plasticizer, a dispersant, an anti-settling agent, an antifoaming agent, a release agent, a leveling agent and the like are added to the coating liquid in order to improve the coating property and the like.

The plasticizer is added for the purpose of controlling the fluidity and drying rate of the ink. For example, normal alkyl phthalates such as dimethyl phthalate, dibutyl phthalate, di-n-octyl phthalate, di-2-ethylhexyl phthalate, diisodecyl Phthalates such as phthalate, butylbenzyl phthalate, diisononyl phthalate, ethyl phthalethyl glycolate, butyl phthalyl butyl glycolate, tri-2-ethylhexyl trimellitate, tri-n-alkyl trimellitate, triisononyl trimethylate Trimellitate esters such as melitate and triisodecyl trimellitate, dimethyl adipate, dibutyl adipate, di-2-ethylhexyl adipate, diisodecyl adipate, dibutyl diglycol adipate Di 2-ethylhexyl azelate Tate, dimethyl sebacate, dibutyl sebacate, di 2
Aliphatic dibasic acid esters such as -ethylhexyl sebacate, di-2-ethylhexyl malate, acetyl-tri- (2-ethylhexyl) citrate, acetyl-tri-n-butyl citrate and acetyl tributyl citrate, and polyethylene glycol benzoate Glycol derivatives such as triethylene glycol-di- (2-ethylhexoate) and polyglycol ether, glycerin derivatives such as glycerol triacetate and glycerol diacetyl monolaurate, sebacic acid, adipic acid, azelaic acid and phthalic acid. Polyester, low molecular weight polyether having a molecular weight of 300 to 3,000, low molecular weight poly-α-styrene, low molecular weight polystyrene, trimethyl phosphate, triethyl phosphate, tributyl phosphate Eto, tri-2-ethylhexyl phosphate, tributoxyethyl phosphate,
Triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, 2
Orthophosphoric acid esters such as -ethylhexyldiphenyl phosphate, ricinoleic acid esters such as methylacetyl ricinoleate, poly-1,3-butanediol adipate, polyester epoxidized esters such as epoxidized soybean oil, glycerin triacetate, Acetates such as -ethylhexyl acetate;

The dispersant and anti-settling agent are intended to improve the dispersibility and anti-settling properties of the colored phosphor particles, and include, for example, phosphate ester type, silicone type, castor oil ester type, various interface lubricants And the like. Examples of the antifoaming agent include silicone-based, acrylic-based, various interfacial lubricants and the like, and examples of the release agent include silicone-based and
Fluoro-oil type, paraffin type, fatty acid type, fatty acid ester type, castor oil type, wax type, compound type are exemplified, and as the leveling agent, for example, fluorine type, silicone type, various interfacial lubricants and the like are exemplified, It is added in an appropriate amount.

The above materials include anones such as methanol, ethanol, isopropanol, acetone, methyl ethyl ketone, toluene, xylene, cyclohexanone, methylene chloride, 3-methoxybutyl acetate, ethylene glycol monoalkyl ethers, ethylene glycol alkyl ether acetates, Diethylene glycol monoalkyl ethers, diethylene glycol monoalkyl ether acetates, propylene glycol monoalkyl ethers, propylene glycol monoalkyl ether acetates, dipropylene glycol monoalkyl ethers, dipropylene glycol monoalkyl ether acetates, α- or β- Dissolved or dispersed in terpenes such as terpionaire, N-methyl-2-pyrrolidone Then, the mixture is adjusted to have an appropriate viscosity to form a coating liquid.

Next, the composition for forming a phosphor layer when the resin to be removed by firing is a photosensitive resin will be described.

The photosensitive resin comprises a binder polymer and a polymerizable monomer, and if necessary, comprises a photoinitiator, a sensitizer, a polymerization terminator, and a chain transfer agent.

As the binder polymer, acrylic acid, methacrylic acid, dimer of acrylic acid (M-5600 manufactured by Toagosei Co., Ltd.), itaconic acid, crotonic acid, maleic acid, fumaric acid, and acid anhydride of vinyl acetate And at least one of methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-propyl acrylate, n-propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, se
c-butyl acrylate, sec-butyl methacrylate, n-butyl methacrylate, n-butyl acrylate, isobutyl acrylate, isobutyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, n-pentyl acrylate, n-pentyl methacrylate, n-hexyl acrylate , N-
Hexyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, n-octyl acrylate, n-octyl methacrylate, n-decyl acrylate, n-decyl methacrylate, styrene, α-methylstyrene, N-vinylpyrrolidone A polymer or a copolymer, or a mixture of two or more of these copolymers may be used.
Examples of such copolymers include polymers obtained by adding an ethylenically unsaturated compound having a glycidyl group or a hydroxyl group to these copolymers. Further, polyvinyl alcohol, polyvinyl butyral, acrylate polymer, methacrylate polymer, polystyrene, α-methylstyrene polymer, 1-vinyl-2-pyrrolidone polymer, and copolymers thereof are also included.

In order to make the obtained photosensitive resin composition a diluted alkali developing type, an ethylenically unsaturated carboxylic acid such as acrylic acid or methacrylic acid is copolymerized to have an acid value of 50 to 15.
0 mgKOH / g. The weight average molecular weight of the binder polymer is from 3,000 to 200,000, preferably from 10,000 to 100,000.

Examples of the polymerizable monomer include compounds having at least one polymerizable carbon-carbon unsaturated bond. For example, allyl acrylate, benzyl acrylate, butoxyethyl acrylate, butoxyethylene glycol acrylate, cyclohexyl acrylate, dicyclopentanyl acrylate, dicyclopentenyl acrylate, 2-ethylhexyl acrylate,
Glycerol acrylate, glycidyl acrylate,
2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, isobonyl acrylate, isodexyl acrylate, isooctyl acrylate, lauryl acrylate, 2-methoxyethyl acrylate,
Methoxyethylene glycol acrylate, phenoxyethyl acrylate, stearyl acrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6
-Hexanediol diacrylate, 1,3-propanediol diacrylate, 1,4-cyclohexanediol diacrylate, 2,2-dimethylolpropane diacrylate, glycerol diacrylate, tripropylene glycol diacrylate, glycerol triacrylate, trimethylol Propane triacrylate, polyoxyethylated trimethylolpropane triacrylate, propylene glycol modified trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, triethylene glycol diacrylate, polyoxypropyl trimethylolpropane triacrylate, Butylene glycol diacrylate, 1,2,4-
Butanetriol triacrylate, 2,2,4-trimethyl-1,3-pentanediol diacrylate, diallyl fumarate, 1,10-decanediol dimethyl acrylate, dipentaerythritol hexaacrylate, and the above acrylate to methacrylate One or two such as γ-methacryloxypropyltrimethoxysilane, 1-vinyl-2-pyrrolidone, etc.
Mixtures of more than one species.

The amount of the polymerizable monomer used is from 20 parts by weight to 200 parts by weight based on 100 parts by weight of the crosslinkable binder polymer.
It is advisable to include parts by weight.

As the photoinitiator, benzophenone, methyl o-benzoylbenzoate, 4,4-bis (dimethylamino) benzophenone, 4,4-bis (diethylamino) benzophenone, α-aminoacetophenone, 4,4- Dichlorobenzophenone, 4-benzoyl-4-methyldiphenylketone, dibenzylketone, fluorenone, 2,2-diethoxyacetophenone, 2,
2-dimethoxy-2-phenylacetophenone, 2-hydroxy-2-methylpropiophenone, p-tert
-Butyldichloroacetophenone, thioxanthone, 2
-Methylthioxanthone, 2-chlorothioxanthone,
2-isopropylthioxanthone, diethylthioxanthone, benzyldimethylketal, benzylmethoxyethylacetal, benzoinmethylether, benzoinbutylether, anthraquinone, 2-tert-butylanthraquinone, 2-amylanthraquinone, β-
Chloroanthraquinone, anthrone, benzanthrone, dibensuberone, methyleneanthrone, 4-azidobenzylacetophenone, 2,6-bis (p-azidobenzylidene) cyclohexane, 2,6-bis (p-azidobenzylidene) -4-methylcyclohexanone,
-Phenyl-1,2-butadione-2- (o-methoxycarbonyl) oxime, 1-phenyl-propanedione-2- (o-ethoxycarbonyl) oxime, 1,3-
Diphenyl-propanetrione-2- (o-ethoxycarbonyl) oxime, 1-phenyl-3-ethoxy-propanetrione-2- (o-benzoyl) oxime, Michler's ketone, 2-methyl- [4- (methylthio) phenyl]- 2-morpholino-1-propane, 2,2-dimethoxy-1,2-diphenylethan-1-one, 2-
Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2,4-diethylthioxanthone, p-dimethylaminobenzoic acid isoamyl ester, p-dimethylaminobenzoic acid ethyl ester, naphthalenesulfonyl chloride, Quinoline sulfonyl chloride, n-phenylthioacridone, 4,4-azobisisobutyronitrile, diphenyl disulfide, benzothiazole disulfide, triphenylphosphine, camphorquinone, carbon tetrabromide, tribromophenyl sulfone, benzoyl peroxide, Examples include a combination of a photoreducing dye such as eosin and methylene blue and a reducing agent such as ascorbic acid and triethanolamine. Further, one or more of these photoinitiators may be used in combination.

In the case of the negative type, the photosensitive resin may be contained in an amount of 5 to 60 parts by weight, preferably 10 to 40 parts by weight, based on 100 parts by weight of the colored phosphor particles. If the amount of the photosensitive resin is more than 60 parts by weight, carbon remains in the film after firing, and the quality is undesirably deteriorated.

If necessary, the above-mentioned plasticizer, dispersant, anti-settling agent, antifoaming agent, release agent, leveling agent, etc. are added to the coating liquid, and the coating solution is dissolved or dispersed in the same solvent as described above. To form a coating solution.

Further, in addition to using the phosphor layer forming composition as a coating solution, a coating solution is applied on a base film to form a phosphor layer forming layer. Is also good. To fill the phosphor layer forming layer in the cell using the transfer sheet, the transfer sheet is stacked on the cell, and then the phosphor layer is formed using a convex mold or roll that matches the concave portion of the cell. The layer may be pressed into the cell. Therefore, it is necessary that the base film is not affected by the solvent in the coating liquid for forming and does not shrink and stretch in the drying step of the solvent, but is also required to have flexibility.

Examples of the base film include polyethylene terephthalate, 1,4-polycyclohexylene dimethylene terephthalate, polyethylene naphthalate,
Polyphenylene sulfide, polystyrene, polypropylene, polysulfone, aramid, polycarbonate,
Polyvinyl alcohol, cellophane, cellulose derivatives such as cellulose acetate, polyethylene, polyvinyl chloride, nylon, polyimide, each film such as ionomer, further, aluminum, metal foils such as copper are exemplified, the film thickness 4μm ~ 400μm, preferably 4.5 μm to 200
μm.

Next, a substrate for producing a PDP will be described as an example to which the composition for forming a phosphor layer of the present invention is applied.

Next, the method for forming a phosphor layer of the present invention will be described by taking a phosphor layer on a PDP back plate as an example.

The method of manufacturing a phosphor layer will be briefly described with reference to FIG. 1 as an example.
An address electrode 8 is formed on the upper surface with or without a base layer.

The electrodes can be formed by (1) a method of combining a thin film forming process such as a sputtering method or a vacuum evaporation method with a photo process, (2) a cost method using screen printing, and (3) a plate. There is a method combining a coating method such as a coat or a reverse coat with a photo process. As a photo process, there is a method in which a photoresist is applied and dried, and then patterning is performed by an exposure and development process, or a method in which patterning is similarly performed using a dry film resist.
The thickness of the electrode is, for example, 0.05 μm when Cr is used as an electrode material and the film is formed by a sputtering method.
The formed Cr thin film is patterned using a photoresist to form an electrode. The electrode material and the patterning method are not limited to these methods.

After the address electrodes 8 having a predetermined pattern are formed by using any of the above methods, the barrier ribs 3 are formed. As the rib material, a glass paste obtained by mixing a low-melting glass powder mainly composed of lead oxide, a resin removable by firing such as ethyl cellulose, and a solvent is used, and the pattern-like barrier rib 3 is formed by overprinting screen printing. Form. Alternatively, after applying and drying a rib material on the entire surface by solid screen printing, blade coating, reverse coating, or the like, a resist is applied to the entire surface, or a dry film resist is attached, and the pattern of the barrier rib 3 is exposed. After that, patterning is performed by developing, and then unnecessary portions of the rib material are removed by sandblasting to form a predetermined rib shape. In any case of the screen printing method and the sand blast method, baking is performed thereafter. The height of the formed barrier rib is 10 μm
About 200 μm.

In the PDP having the shape shown in FIG. 2, the dielectric layer 6 'is preferably formed using a glass paste made of low melting point glass.
The thickness is preferably 1 μm to 50 μm.

In order to form a phosphor layer on such a PDP substrate, a coating solution is formed by screen printing on the electrodes 12 between the cell barriers. The concentration and application amount of the phosphor layer forming composition may be appropriately set so that a sufficient discharge space is formed in the cell by subsequent drying and firing. As a coating method, a dispense coat, a die coat, a blade coat, a comma coat, a roll coat, a gravure reverse coat method, a slit reverse method, or the like may be used in addition to screen printing.

Further, in addition to the above-mentioned coating method, after coating the phosphor layer forming layer using a transfer sheet using a transfer sheet, the portions other than the phosphor layer pattern are interposed via a sandblast mask. The phosphor layer may be formed by removing the phosphor layer by sandblasting. Sand blasting is a method in which abrasive fine particles mixed with a compressed gas are jetted at a high speed and physically etched.

When the coating liquid is made of a photosensitive resin, it may be applied by the same coating method as the above-mentioned thermoplastic resin and then light-cured. Sandblasting can also be applied. When the photosensitive resin is an alkali-developing binder polymer, the coating is performed including between cells, or the phosphor layer forming layer is transferred, and then exposed and developed through a photomask having a phosphor layer pattern to perform the fluorescent treatment. A body layer can be formed.

To display a PDP in color, red, green,
It is preferable to sequentially form a phosphor layer forming layer on each of the blue display portions using a coating solution or a transfer sheet of each color.

After forming the phosphor layer forming layer, the temperature of 300 ° C.
It is fired at 550 ° C. to form a phosphor layer.

The back plate thus formed is shown in FIG.
As shown in (1), after sealing with a front plate, a gas such as neon, xenon, or the like is sealed in the cell to produce an AC type PDP.

[0056]

The present invention will be described below with reference to examples. In the examples, "parts" indicates parts by weight.

(Example 1) (Production of colored phosphor particles emitting red light) Phosphor particles emitting red light (Y, Gd) BO ₃ : Eu (manufactured by Kasei Optonics, average particle size 4.7 μm) ) 200 parts and red pigment TO
R (manufactured by Dainichi Seika Kogyo Co., Ltd., average particle size: 0.05 μm) and 4 parts thereof were charged into a mechanofusion system (manufactured by Hosokawa Micron, Inc., model AM-15F), and the rotor speed was set to 15
The treatment was performed for 45 minutes under the operating conditions of 50 rpm, a stator clearance of 2 mm, and a scraper clearance of 1 mm to produce red phosphor particles of the present invention.

FIG. 3 (a) shows an electron micrograph (magnification: 20,000) of the phosphor particles used as the raw material, and FIG. 3 (b) shows an electron micrograph (magnification: 20,000) of the phosphor particles coated with the pigment. Shown in From FIG. 3 (b), the surface of the phosphor particles is coated with a red pigment.
Fusing is observed. (Preparation of composition for forming red phosphor layer) The following composition: Red phosphor particles prepared above: 100 parts Ethyl cellulose (STD-100 manufactured by Dow Chemical Company): 8 parts Solvent (terpineol) ... 72 parts were kneaded using a three-roll mill C-4.3 / 3/4 × 10 (manufactured by Inoue Seisakusho), and then diluted with a solvent to obtain a phosphor layer-forming composition (viscosity of 250 poise) of the present invention. , 23 ° C).

(Example 2) (Preparation of phosphor particles emitting green light) Phosphor particles emitting green light Zn ₂ SiO ₄ : Mn (manufactured by Kasei Optonics Co., Ltd., average particle size: about 3.9 μm) 200 And 10 parts of a green pigment “Dipiroxide Side Green # 3340 (manufactured by Dainichi Seika Kogyo Co., Ltd., average particle size 0.04 μm)” by a mechanofusion system (manufactured by Hosokawa Micron, model AM-1
5F), rotor speed 1550 rpm, stator clearance 2 mm, scraper clearance 1
The treatment was performed for 45 minutes under the operating condition of mm to produce green phosphor particles of the present invention.

FIG. 4A shows an electron micrograph (20,000 ×) of the phosphor particles used as the raw material, and FIG. 4B shows an electron micrograph (20,000 ×) of the green phosphor particles of the present invention. Shown in
From FIG. 4B, it is observed that the green pigment is coated and fused on the surface of the phosphor particles.

(Preparation of Green Phosphor Layer Forming Composition) The following composition: Green phosphor particles prepared above: 100 parts Ethyl cellulose (STD-100 manufactured by Dow Chemical Co., Ltd.): 8 parts Solvent (Terpineol) ... 72 parts were kneaded using a three-roll mill C-4.3 / 3 x 10 (manufactured by Inoue Seisakusho), and then diluted with a solvent, and the composition for forming a phosphor layer of the present invention ( (Viscosity 250 poise, 23 ° C.).

(Example 3) (Production of colored phosphor particles emitting blue light) Phosphor particles BaMgAl ₁₄ O ₂₃ : Eu (manufactured by Kasei Optonics Co., Ltd., average particle size of about 4.0 μm) emitting blue light 200 And 20 parts of a blue pigment “Dipiroxide Side Blue # 3450 (manufactured by Dainichi Seika Kogyo Co., Ltd., average particle size 0.04 μm)” by a mechanofusion system (manufactured by Hosokawa Micron, model AM-1
5F), rotor speed 1550 rpm, stator clearance 2 mm, scraper clearance 1
The treatment was performed for 45 minutes under the operating condition of mm to produce blue phosphor particles of the present invention.

FIG. 5A shows an electron micrograph (magnification: 20,000) of the phosphor particles used as the raw material, and FIG. 5B shows an electron micrograph (magnification: 20,000) of the blue phosphor particles of the present invention. Shown in
From FIG. 4B, it is observed that the blue pigment is coated and fused on the phosphor particle surface.

(Preparation of Blue Phosphor Layer Forming Composition) The following composition: Blue phosphor particles prepared above: 100 parts Ethyl cellulose (STD-100 manufactured by Dow Chemical Co., Ltd.): 8 parts Solvent (Terpineol) ... 72 parts were kneaded using a three-roll mill C-4.3 / 3 x 10 (manufactured by Inoue Seisakusho), and then diluted with a solvent, and the composition for forming a phosphor layer of the present invention ( (Viscosity 250 poise, 23 ° C.).

Comparative Example 1 In the composition for forming a phosphor layer in Example 1, phosphor particles (Y, Gd) BO ₃ : Eu (manufactured by Kasei Optonics Co., Ltd., instead of colored phosphor particles) 200 parts, Red pigment TOR (manufactured by Dainichi Seika Kogyo Co., Ltd., average particle size: 0.05 μm): 4 parts and an ordered mix, and 100 parts thereof are similarly used. A composition for forming a phosphor layer was prepared.

Comparative Example 2 In the composition for forming a phosphor layer in Example 2, instead of the colored phosphor particles, phosphor particles Zn ₂ SiO ₄ : Mn (manufactured by Kasei Optonics Co., Ltd .; 3.9 μm) ··· 200 parts ・ Green pigment “Dipiroxide Green # 3340 (manufactured by Dainichi Seika Kogyo Co., Ltd., average particle size 0.04 μm) ··· 10 parts and ordered mixed, and 100 parts thereof Was similarly used to prepare a phosphor layer forming composition.

Comparative Example 3 In the composition for forming a phosphor layer in Example 3, instead of colored phosphor particles, phosphor particles BaMgAl ₁₄ O ₂₃ : Eu (manufactured by Kasei Optonics Co., Ltd., average particle size of about 4) ) 200 parts-Blue pigment "Dipiroxide Blue # 3450 (manufactured by DAINICHI SEIKA KOGYO CO., LTD., Average particle size 0.04 µm) ... 20 parts and ordered mixed, and 100 parts thereof are the same. Was used to prepare a phosphor layer forming composition.

Comparative Example 4 In the composition for forming a phosphor layer in Example 1, phosphor particles (Y, Gd) BO ₃ : Eu (manufactured by Kasei Optonics, average particles) were used instead of the colored phosphor particles. A composition for forming a phosphor layer was similarly prepared using 100 parts (diameter 4.7 μm).

Comparative Example 5 In the composition for forming a phosphor layer in Example 2, instead of the colored phosphor particles, phosphor particles Zn ₂ SiO ₄ : Mn (manufactured by Kasei Optonics Co., Ltd., average particle size of about 3) 9.9 μm), and a phosphor layer forming composition was prepared in the same manner using 100 parts.

Comparative Example 6 In the composition for forming a phosphor layer in Example 3, phosphor particles BaMgAl ₁₄ O ₂₃ : Eu (manufactured by Kasei Optonics Co., Ltd.) were used instead of the colored phosphor particles.
Using 100 parts of an average particle size of about 4.0 μm, a composition for forming a phosphor layer was similarly prepared.

(Preparation of Panel Back Plate) ELD-1155 (Okuno Pharmaceutical Co., Ltd.) as a base layer on a glass substrate
Are stacked, and D-59 is used as an address electrode on the underlayer.
0-HV-MOD (manufactured by ESL Japan Co., Ltd.) was patterned by a screen printing method.

Next, using a glass paste PLS-3550 [manufactured by Nippon Electric Glass Co., Ltd.] obtained by mixing a powder of low melting point glass mainly composed of lead oxide and a binder composed of ethyl cellulose and a solvent, screen printing was repeated. After lamination in a pattern by printing, it was baked at a peak temperature of 560 ° C. to form a barrier rib having a height of 120 μm.
The back plate of the PDP shown in FIG.

(Method for Forming Phosphor Layer) PDP Obtained Above
After filling each of the phosphor layer forming compositions prepared in Examples 1 to 3, Comparative Examples 1 to 3, and Comparative Examples 4 to 6 between the cell barriers on the back plate by using a screen plate with a squeegee. Baked at a peak temperature of 450 ° C. for 30 minutes to burn off organic components, whereby Examples 1 to 3 and Comparative Examples 1 to
3. Three types of back plates having phosphor layers of combinations of R, G, and B of Comparative Examples 4 to 6 were obtained.

(Preparation of AC type PDP) After a transparent electrode material is formed on a glass substrate, a sustain electrode is formed by etching, and then a bus electrode is formed by screen printing using a conductive paste and firing. Further, the dielectric layer 6, Mg
The front plate prepared by sequentially forming the O layer was combined with the back plate prepared above, and after sealing, a gas such as neon or xenon was sealed in the cell to prepare an AC type PDP.

(Evaluation 1) The composition for forming a phosphor layer of each of Examples and Comparative Examples was used to form a film having a thickness of 25 μm on a glass substrate.
m, a 5 × 5 cm solid film was printed by screen printing, dried, baked at a peak temperature of 450 ° C. for 30 minutes, and the reflectance in the 400 nm to 700 nm region was measured. The reflectance was measured using a spectrophotometer CM-1000 manufactured by Minolta Co., Ltd.

Table 1 shows the results of Examples 1 to 3, and Comparative Examples 1 to
Table 2 shows the results of No. 6.

[0077] As can be seen from the comparison between Table 1 and Table 2, it is understood that the samples of Examples 1 to 3 have low reflectance.

(Evaluation 2) Each of R, G, and
PDP panel (the panel of the present invention) produced using a back plate on which a phosphor layer of the combination of B was formed, and Comparative Examples 1 to 3
PDP panel [Comparative panel (1)] manufactured by using the above, and PD manufactured by using Comparative examples 4 to 6
With respect to the three types of PDPs of the P panel [Comparative Panel (2)], the luminance and the contrast under a dark room and under 230 lux illuminance were determined. Table 3 shows the luminance and contrast under a dark room, and Table 4 shows the luminance and contrast under a 230-lux illuminance. The unit of luminance is cd / m ² .

[0079] ¹⁾ : Based on the W luminance of an uncolored product.

[0080] As can be seen from the comparison between Tables 3 and 4, the panel of the present invention is excellent in contrast, and particularly from Table 4, it is understood that the panel is excellent in reflectance and contrast under external light.

[0081]

The colored phosphor particles and the composition for forming a phosphor layer of the present invention are capable of forming a phosphor layer having reduced external light reflectance and improved contrast.
It is useful for forming a phosphor layer in plasma display panels, fluorescent display tubes, cathode ray tubes, cathode ray tubes, and the like.

[Brief description of the drawings]

FIG. 1 is a perspective view for explaining an AC type plasma display panel.

FIG. 2 is a cross-sectional view for explaining another example of an AC type plasma display panel.

FIG. 3 is an electron micrograph of the colored phosphor particles produced in Example 1.

FIG. 4 is an electron micrograph of the colored phosphor particles produced in Example 2.

FIG. 5 is an electron micrograph of the colored phosphor particles produced in Example 3.

[Explanation of symbols]

1 is a front plate, 2 is a back plate, 3 is a cell barrier, 4 is a sustain electrode, 5 is a bus electrode, 6, 6 'are dielectric layers, and 7 is MgO.
The layer 8 is an address electrode, 9 is a phosphor layer, and 10 is an underlayer.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01J 11/02 H01J 11/02 B 17/04 17/04

Claims (6)

[Claims] 1. A colored phosphor particle, wherein a pigment is fused and coated on the surface of the phosphor particle. 2. An average particle size of the pigment is not more than an average particle size of the phosphor particles, and a fusion / coating amount of the pigment is 0.1% by weight to 50% by weight based on the phosphor particles. The colored phosphor particles according to claim 1, characterized in that: 3. The colored phosphor particles according to claim 1, wherein the pigment has the same color as the emission color of the phosphor particles. 4. The colored phosphor particles according to claim 1, wherein the pigment is a black pigment. 5. A composition for forming a phosphor layer, comprising colored phosphor particles having a surface fused and coated with a pigment, a resin and a solvent which can be removed by firing. 6. The phosphor layer forming composition according to claim 5, wherein the phosphor layer is a phosphor layer in a plasma display panel.