JPH0762339A - Fluorescencer film and its making - Google Patents

Abstract

PURPOSE:To obtain a fluorescencer film reduced in the dispersion of thickness and composition and having a high luminous efficiency by applying a paste composition containing an organometallic compound to a substrate and heat- decomposing the applied composition by firing. CONSTITUTION:At least one organometallic compound is mixed with 5-50wt.% thickener such as nitrocellulose or PE, 5-50wt.% film formation modifier such as stearic acid or dibutyl phthalate and an organic solvent to obtain a paste composition having a solid concentration of 5-50wt.%. An electrode 12, an insulation layer 13 and a protective layer 14 are formed on a substrate 11. The above paste composition is printed on or applied to the protective layer 14, and heat- decomposed by heating to 350-1500 deg.C for 30min to 10hr to form a fluorescencer film 15 of a thickness of 0.01-1mum.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phosphor film and a method for producing the same.

[0002]

2. Description of the Related Art Fluorescent materials include fluorescent lamps, cathode ray screens, scintillation counters, and fluorescent display tubes (VF).
D), plasma display panel (PDP), electroluminescence display (ELD) and so on.

In most cases, the phosphors used for such applications are synthesized by solid-state reaction (calcination) at high temperature. In the conventional synthesis process, well-purified base materials, activators, fluxing agents, and other raw materials are mixed, placed in a crucible, fired in a furnace, and after the reaction is complete, crushed by an appropriate method and further coarsened. Classify to remove particles and fine particles. Then, washing, surface treatment, and sieving are performed to obtain a phosphor powder. Further, this phosphor powder is used for various purposes by forming a phosphor film by a slurry method, a printing method, or the like (see Phosphor Handbook Ohmsha).

However, in the case of ELD, there is no defect,
Since a dense phosphor film (light emitting layer) having high crystallinity is required, the phosphor film is formed by an electron vapor deposition method, a sputtering method, or the like instead of the above method.

[0005]

The conventional production of a phosphor by a solid-phase reaction requires a multi-step process including a reaction process requiring a high temperature, and the high purity required for the phosphor is required. Ingredients and trace ingredients (activators)
It is difficult to control the addition amount of the compound, and further, after pulverization or the like, the light emission rate is decreased, and there is a problem that the yield is decreased because particles other than the target particle size are removed. In addition, for applications such as the display as described above, a separate step for thinning is necessary, and since the phosphor film has to be uniformly formed, there are many problems in terms of cost and quality. Was there.

An object of the present invention is to provide a phosphor film and a method for producing the same, which can solve the above-mentioned problems of the prior art.

According to one feature of the invention, on the substrate:
There is provided a phosphor film formed by printing or applying a paste composition containing at least one kind of organometallic compound, firing and pyrolyzing the paste composition.

[0008]

According to another feature of the present invention, a substrate is prepared, a paste composition containing at least one organometallic compound is prepared, and the paste composition is printed on the substrate. Alternatively, there is provided a method for producing a phosphor film, which comprises the steps of applying and baking the paste composition printed or applied on the substrate and thermally decomposing it to form the phosphor film.

[0009]

In the phosphor film produced by the present invention, a high purity material system having a high purity can be mixed in a strictly controlled ratio, so that a high purity phosphor film having a controlled composition can be easily produced. Further, not only can a phosphor film having a small variation in film thickness and composition and high emission efficiency be efficiently manufactured in a small number of steps, but also a large reduction in manufacturing steps and manufacturing costs can be expected.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail with reference to the accompanying drawings.

The present invention is to produce a phosphor film by printing or coating a paste composition containing at least one kind of organometallic compound on a substrate, and firing and pyrolyzing the paste composition. Is easy to be highly purified by a method similar to a usual organic compound purification method such as vacuum distillation, sublimation, and recrystallization, and
By dissolving these in an organic solvent and liquefying them, trace components such as an activator can be uniformly added with good control.

Further, according to the present invention, a paste suitable for many purposes can be prepared without including a step of making fine particles such as crushing and by adding additives such as a thickener and a film-forming preparation agent. . Paste, print (or apply),
A phosphor film can be produced by only three steps of baking. Moreover, by optimizing the additives and firing conditions for forming a paste, it is possible to produce a dense phosphor film with little variation in film thickness and composition. Therefore, the phosphor film for ELD or the like, which has been conventionally manufactured by the electron beam evaporation method or the sputtering method, can be manufactured by the method of the present invention.

First, before describing specific examples of the present invention, examples of various substances and materials used in the present invention will be described.

The organometallic compound used in the present invention includes
Any conventionally known compound can be arbitrarily selected. For example, it may be composed of metal alcoside, octylate, naphthenate, metal acetylacetonate, or the like.

As a constituent of the phosphor film, Ca,
W, Ba, Si, Zn, Cd, P, Sr, Mg, As,
Ge, Y, V, Ga, Pb, Mn, Ti, Sn, Eu,
Er, Sm, Tm, Tb, Dy, Al, Nd, Ce, B
i, Fe, S, Ag, Cu, F, Cl, Br, I, H
f, Tl, B, Na, Be, K, In, Pt, Ru, I
It contains r, Pd, Rh, Co, Ni and the like.

As an additive constituting the paste, a thickening agent such as nitrocellulose, carboxymethyl cellulose, and other cellulose-based materials, polyethylene, polystyrene,
Examples include general-purpose polymers such as polypropylene, polymethylmethacrylate, polyethylmethacrylate, and polycarbonate, and natural polymer compounds such as resins and asphalt. The addition amount is preferably about 5 to 50 wt%.

Examples of the film forming agent include fatty acids such as stearic acid, arachidic acid, linoleic acid, and linolenic acid, and fulleric acid esters such as dibutyl phthalate and dioctyl phthalate. 5 to 50 wt.
% Is preferable.

Organic solvents for dissolving or diluting metal organic compounds include aliphatic hydrocarbons such as octane, decane and tridecane, aromatic hydrocarbons such as toluene and xylene, halogenated hydrocarbons such as methylene chloride and chlorobenzene. , Alcohols such as ethanol, butanol, terpineol and ethylene glycol, ketones such as acetone, methyl ethyl ketone and cyclohexanone, ethers such as diethyl ether and tetrahydrofuran, and esters such as ethyl acetate and benzyl acetate. As for the concentration of the solution, the solid content ratio is 5
The range of ˜50 wt% is preferred.

As the substrate, soda glass, borosilicate glass, non-alkali glass, quartz glass, PLZT, P
ZT, BaTiO ₃ , MgO, Si, GaAs, ITO
An inorganic substrate such as a substrate or a heat resistant resin substrate such as polyimide, polyphenylene sulfide, or polyamide can be used.

Examples of the method of applying the paste include bar coating, spin coating, spray coating, dip coating, roll coating and the like, and examples of the paste printing method include screen printing and the like. .

As the method of firing and thermal decomposition of these coating films or printed films, the thermal decomposition temperature of the paste material (organic metal compound, additive, solvent) used in an electric furnace such as a muffle furnace, a belt furnace or an infrared furnace. Although the above conditions are sufficient, it is preferable to perform baking at a baking temperature of 350 to 1500 ° C. for about 30 minutes to 10 hours in order to completely perform thermal decomposition and stabilize the oxidized state of the film after baking. . If the firing temperature is low, thermal decomposition may be insufficient and crystallization may not proceed, resulting in a decrease in luminous efficiency. If it is too high, a reaction with the substrate may proceed, resulting in a decrease in luminous efficiency. The firing time may be 10 hours or more, but in particular,
It is not necessary to do it for more than 10 hours. Examples of the firing atmosphere include reducing atmospheres such as hydrogen and water vapor, reactive atmospheres such as hydrogen sulfide, and reduced pressure.

The film thickness after firing varies depending on the viscosity, coating and printing method, etc., but if it is too thick, defects such as cracks occur, so a film thickness of about 0.01 to 1 μm is preferable for one coating and firing. . If more film thickness is required,
By repeating coating and baking, the film can be made as thick as desired.

After firing, heat treatment may be performed in order to improve the crystallinity of the phosphor film and reduce defects in the film. The heat treatment temperature is preferably about 400 ° C to 1500 ° C, and the heat treatment time is preferably about 30 minutes to 10 hours.

Next, specific examples of the present invention will be described.

Example 1 Fluorescent lamp Ba naphthenate, Mg 2-ethylhexanoate, Al 2-ethylhexanoate and tris (pivaloyltrifluoroacetonato) Eu in atomic ratio BaMgAl16O24:
It was blended so as to be Eu0.01. This composition is designated as A. Based on the composition A, a phosphor paste composition having the following composition was produced. Phosphor paste composition Composition A 1 part by weight Polybutyl methacrylate 1 part by weight (10 wt% terpineol solution) Dioctyl phthalate 1 part by weight Linoleic acid 1 part by weight

The above phosphor paste composition was applied to a bulb for a fluorescent lamp and dried at room temperature for about 10 minutes, and then 500
Firing was performed in a furnace at a temperature of ° C for about 30 minutes under a nitrogen stream. The valve thus obtained was filled with an electrode by a known method, evacuated, filled with a filling gas and aged, and λmax was 45.
A blue fluorescent lamp of 0 nm emission color was obtained.

Example 2 Fluorescent lamp 2-ethylhexanoic acid Y, naphthenic acid V, and 2-ethylhexanoic acid Bi were blended so that the atomic ratio was YVO4: Bi0.02. This composition is designated as A. Based on the composition A, a phosphor paste composition having the following composition was produced. Phosphor paste composition Composition A 1 part by weight Polymethylmethacrylate 1 part by weight (10 wt% THF solution) Dioctyl phthalate 1 part by weight Linolenic acid 0.5 part by weight

A fluorescent lamp was obtained in the same manner as in Example 1 except that the fluorescent lamp was fired in the air. λmax was 565 nm, and the emission color was white.

Example 3 PDP (plasma display)
Panel) 2-ethylhexanoic acid Y and tris (pivaloyltrifluoroacetonato) Eu in atomic ratio Y2O3: Eu0.01
It was blended so that This composition is designated as A. Based on A, a phosphor paste composition having the following composition was produced. Phosphor paste composition Composition A 1 part by weight Polyethylmethacrylate 1 part by weight (10 wt% THF solution) Dioctyl phthalate 1 part by weight Linoleic acid 1 part by weight

As shown in the partially enlarged sectional view of FIG. 1, ITO is vapor-deposited on a heat-resistant glass substrate 11 having a thickness of 2 mm and a striped electrode (anode) is formed by photolithography.
Twelve. An insulating layer 13 made of low-melting glass is formed on the electrode 12 by a screen printing method to form a protective layer 1
As No. 4, a MgO film was produced by vapor deposition. Furthermore, a phosphor paste was applied to the upper layer thereof, dried at room temperature for 10 minutes, and then baked at 500 ° C. for 1 hour to prepare a phosphor film 15, which was used as a surface plate 10.

An electrode (cathode) 22 was formed by vapor-depositing Ni on the same glass substrate 21 and by photolithography so as to face and cross the ITO electrode 12 described above. An insulating layer 23 and a protective layer 24 were sequentially laminated on the upper layer by the same method as described above to form a back plate 20.

The front plate 10 and the rear plate 20 were sealed, evacuated, filled with Ne gas (mixed with several% of Ar), and then sealed to manufacture a PDP. Electrode 12 and electrode 22
When an AC voltage of 100 V / 50 kHz was applied between and, red emission was confirmed.

Example 4 PDP Ba naphthenate, Al 2-ethylhexanoate and Mn 2-ethylhexanoate in atomic ratio BaAl12O19: Mn
It was blended so as to be 0.01. This composition is designated as A.
B in the atomic ratio of Ba naphthenate, Mg 2-ethylhexanoate, Mg 2-ethylhexanoate, Al 2-ethylhexanoate, and tris (pivaloyltrifluoroacetona) Eu.
It was blended so as to be aMgAl14O23: Eu0.01. This composition is designated as B.

The phosphor paste compositions were prepared in the same manner as in Example 3 except that the compositions A and B were used. Further, in the same manner as in Example 3, P
DP was prepared.

The PDPs made from compositions A and B are
It emitted green and blue light, respectively. In addition, Example 3,
In Fig. 4, three kinds of phosphor films were produced as separate PDPs, but each phosphor film is arranged as a phosphor film of one PDP, for example, in a stripe shape or in a dot shape, and intersecting electrode rows It is possible to operate as a color plasma display by causing plasma emission in.

Example 5 VFD (Fluorescent Display Tube) A phosphor paste composition having the following composition was prepared. Phosphor paste composition Zinc 2-ethylhexanoate 1 part by weight Polybutylmethacrylate 1 part by weight (10 wt% terpineol solution) Dibutyl phthalate 1 part by weight Linoleic acid 0.5 part by weight

As shown in the enlarged schematic sectional view of FIG. 2, the phosphor paste composition is dip-coated on an aluminum anode plate 32 designated by a ceramic substrate 31, dried at room temperature for 30 minutes, and then at 500 ° C. Then, the phosphor film 33 was produced by firing in the furnace for 1 hour. Next, a cathode 34 formed by coating a tungsten linear heater with an oxide was arranged so as to face the phosphor film 33 on the anode plate 32, and the pair of electrodes 32 and 34 were placed in a hard glass container 35. Then, the container 35 is evacuated, and the degree of vacuum is 10-3.
Sealing was performed at about Pa to obtain a fluorescent display tube. This fluorescent display tube has a peak wavelength of 505 nm 2 when the anode plate voltage is 80 V, the cathode voltage is 1 V, and the current is 50 mA.
Green light emission of ft-L was obtained.

Example 6 Thin film EL device 2-ethylhexanoic acid Y, trisacetylacetonato T
b was blended so that the atomic ratio was Y2O3: Tb0.01. This composition is designated as A. Based on A, a phosphor paste composition having the following composition was produced. Phosphor paste composition Composition A 1 part by weight Polybutyl methacrylate 0.8 part by weight (10 wt% terpineol solution) Dioctyl phthalate 1 part by weight Linoleic acid 1 part by weight

A Ta2O5 thin film was deposited to a thickness of 0.1 μm by a sputtering method on a substrate in which ITO was arranged in a stripe pattern as a transparent conductive film on a glass substrate to form an insulating layer. Next, the above composition was spin-coated at 600 ° C.
In the furnace of No. 1 above, it was baked in the atmosphere for 1 hour to form a phosphor film.
Further, an insulating film similar to the above is formed on this upper layer, and finally, an aluminum film is deposited by a resistance heating method of 0.5 μm using a mask so as to intersect with the transparent conductive film, thereby having a double insulating layer structure. A thin film EL device was produced. 1 for this thin film EL device
When an alternating current of KHz was applied, green EL emission was confirmed at 200V.

Example 7 Thin film EL device A phosphor composition was prepared in the same manner as in Example except that trisacetylacetonato Tm was used instead of trisacetylacetonato Tb in the phosphor paste composition of Example 6. A thin film EL device was manufactured in the same manner as in Example 6 except that the phosphor paste composition was used.
When an alternating current of 1 KHz was applied to this thin film EL element, 2
Blue EL emission was confirmed at 00V.

Example 8 Thin-Film EL Device Same as Example 6 except that tris (pivaloyltrifluoroacetonato) Eu was used in place of trisacetylacetonato Tb in the phosphor paste composition of Example 6. A phosphor composition was prepared, and a thin film EL device was prepared in the same manner as in Example 6 except that this phosphor paste composition was used. When an alternating current of 1 KHz was applied to this thin film EL device, red EL light emission was confirmed at 200V.

In Examples 6, 7 and 8, thin film EL devices emitting green, blue and red were produced using the respective paste compositions. These phosphor paste compositions were striped on the same transparent conductive film. A thin film color EL element can be manufactured by forming the color thin film EL element or the dot shape and driving each independently.

[0043]

INDUSTRIAL APPLICABILITY The present invention has at least a process for producing a phosphor film, which requires a printing process for producing a phosphor powder in a multi-step process including a high temperature process and further forming a film. By printing or applying a paste composition containing one kind of organometallic compound on a substrate, and firing and pyrolyzing the paste composition to produce a phosphor film, not only a great reduction in process and cost can be achieved. By using a high-purity organometallic compound or an additive for stabilizing and homogenizing the paste composition, composition control can be easily performed, and a phosphor film having no defects can be easily produced.

According to the present invention, it is considered that significant cost reduction and improvement in device characteristics such as light emission characteristics are achieved for all devices requiring a phosphor film, and a great effect is exerted on the use of the phosphor film. .

Next, various advantages of applying the phosphor film according to the present invention to various devices will be described for each device.

First, when used for a fluorescent lamp, there are the following advantages. (1) It is not necessary to prepare the phosphor powder in advance, and the phosphor film can be formed from the paste by the process of printing, drying, and firing, and the number of steps can be reduced. (2) The raw material can be highly purified, and the trace elements can be uniformly mixed, so that the luminous efficiency can be improved. Therefore, the same light emission luminance can be obtained with a thinner film thickness, so that the utilization efficiency of the material is high. (3) Since the phosphor film is dense and has few defects, the phosphor film has high strength against the impact of ultraviolet rays, plasma, electron beams, ions, etc., so that the luminance is not lowered and the life is extended.

Next, when it is used for VFD, it has the following advantages. (1) It has the same advantages as when it is used for a fluorescent lamp. (2) Compared with thick film paste (paste of phosphor powder), the uniformity is higher, and a phosphor film having a finer pattern can be manufactured.

When used for a PDP, it has the following advantages. (1) It has the same advantages as those used for fluorescent lamps and VFDs. (2) By selecting the paste material, all layers of the electrode, insulating layer, protective layer, and phosphor layer can be prepared.

When used for ELD, there are the following advantages. (1) It has the same advantages as when it is used for a fluorescent lamp, PDP, and VFD. (2) Since the phosphor film having high crystallinity can be formed, the light emission starting voltage can be reduced and an expensive driving IC is not required. (3) Since the number of defects is small, the withstand voltage is improved. (4) By selecting the paste material, all layers of the electrode, insulating layer and phosphor layer can be prepared.

[Brief description of drawings]

FIG. 1 is a partially enlarged cross-sectional view of a plasma display using a phosphor film according to the present invention.

FIG. 2 is a partial schematic cross-sectional view of a fluorescent display tube using a phosphor film according to the present invention.

[Explanation of symbols]

 10 Surface Plate 11 Glass Substrate 12 Electrode (Anode) 13 Insulating Layer 14 Protective Layer 15 Fluorescent Film 20 Back Plate 21 Glass Substrate 22 Electrode (Cathode) 23 Insulating Layer 24 Protective Layer 31 Ceramic Substrate 32 Anode Plate 33 Fluorescent Film 34 Cathode 35 Hard glass container

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location H01J 9/227 F 7250-5E 11/02 B 17/04 31/15 E 61/42 C

Claims (2)

[Claims] 1. A phosphor film formed by printing or applying a paste composition containing at least one kind of organometallic compound on a substrate, firing and thermally decomposing the paste composition. 2. A substrate is prepared, a paste composition containing at least one kind of organometallic compound is prepared, the paste composition is printed or applied on the substrate, and the paste printed or applied on the substrate. A method for producing a phosphor film, which comprises firing the composition and thermally decomposing it to form a phosphor film.