JP2806724B2 - Method for producing phosphor layer for gas discharge panel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a phosphor layer for a gas discharge panel, and to a method for producing a gas discharge panel having a phosphor layer obtained by the method.

[0002]

2. Description of the Related Art A gas discharge panel generates a discharge by applying a voltage between an anode and a cathode, and the generated electrons collide with a gas such as neon or xenon to generate ultraviolet rays.
It emits light by exciting the phosphor layer. This phosphor is deteriorated by ion bombardment, and its luminance is reduced. Phosphors are used by forming a phosphor layer adhered to the panel wall with a binder.To give this binder the function of protecting the phosphor against ion bombardment, in order to extend the life of the gas discharge panel. is necessary.

[0003] Lead glass, which has been conventionally used as a binder for a phosphor, is more resistant to ion bombardment than a phosphor and has an effect of alleviating ion bombardment of the phosphor. If the amount is large, the ultraviolet light that excites the phosphor is weakened, and the emission of the phosphor is hindered. If the amount is small, the phosphor is subjected to ion bombardment and deteriorates due to insufficient protective effect.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for manufacturing a phosphor layer for a gas discharge panel which can prevent ion bombardment without hindering the emission of the phosphor. It is another object of the present invention to provide a gas discharge panel in which the luminance is hardly reduced by ion bombardment.

[0005]

Means for Solving the Problems As a result of repeated studies to solve the above-mentioned problems, the present inventors have found that oxides of aluminum and / or silicon can withstand ion bombardment, and that aluminum oxide is 141 nm, Silicon is 160
Since it does not absorb ultraviolet light having a wavelength exceeding nm, it has been conceived to form a phosphor layer by coating the surface of the phosphor using such a metal oxide as a binder. The present inventors have found that the above-mentioned object can be achieved by using a specific organic compound contained as a precursor of the binder, and have completed the present invention.

That is, the present invention relates to a method for producing a phosphor layer for a gas discharge panel containing a phosphor and a binder.
As a precursor of the binder, a general formula M (OR) _n (wherein M represents Al or Si; R represents an alkyl group or an alkoxyalkyl group having 2 to 8 carbon atoms which may be the same or different from each other) N represents the valence of M) or a condensate obtained by partial cohydrolysis condensation or partial hydrolysis condensation of a metal element-containing compound represented by the formula: or in the above general formula, M is Al and a part of OR Alternatively, the phosphor is mixed with an amount of a metal element-containing compound which is entirely an alkylacetoacetate group or an acetylacetonato group to give an oxide of 0.5% by weight or more with respect to the phosphor, followed by firing. The present invention also relates to a method for producing a phosphor layer for a gas discharge panel as described above; and to a method for producing a gas discharge panel provided with the phosphor layer obtained by the method.

In the binder used in the present invention, a precursor represented by the general formula M (OR) _n (wherein M and n are as described above; R is the same or different and has 2 carbon atoms) To 8 alkyl groups or alkoxyalkyl groups), or a partial co-hydrolysis of two or more of these metal element-containing organic compounds,
A condensate obtained by condensation is used. Also, M (OR) _n
Among them, those having low volatility even at a high temperature, such as aluminum tris (alkyl acetoacetate) and aluminum tris (acetylacetonate), can be used as a binder precursor as it is. M (OR) _n above
Of the compounds represented by the formula, those having volatility at room temperature to high temperature volatilize before forming a metal oxide by firing. To prevent this, the above condensate is used. Further, in order to form a binder composed of a composite oxide of Si and Al on the surface of the phosphor, a partial cohydrolysis condensate containing both elements may be used. The number of metal elements M in the condensate is preferably in the range of 3 to 15 on average. If the number of M is less than 3, the stability to hydrolysis is still poor depending on the type of R, and the amount of volatilization during firing is large. When the number of M exceeds 15, it is difficult to obtain a uniform coating film.

R may be linear or branched, examples of the alkyl group include ethyl, propyl, butyl, pentyl, hexyl, heptyl and octyl; examples of the alkoxyalkyl group include methoxyethyl, ethoxyethyl and butoxyethyl. . When R is a methyl group, it is susceptible to hydrolysis, so that the paste has poor storage stability and is difficult to handle. An alkyl group or an alkoxyalkyl group having more than 8 carbon atoms is not advisable because the yield of the oxide per weight of the precursor is low.

Further, when M is Al, a part or all of OR may be an alkylacetoacetate group and / or an acetylacetonato group, and examples of the former alkyl group include methyl, ethyl and propyl. You. In this case, as shown in the formula (1), the carbonyl oxygen atom in R coordinates to M to form a chelate ring together with the central element M. In this case, n means the total number of alkoxy groups, alkoxyalkoxy groups and ethyl acetoacetate groups bonded to M.

[0010]

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[0011] Among such R, the organic compound containing a metal element or its partial (co) hydrolytic condensate is stable during storage and exhibits an appropriate hydrolysis rate, and is stable against hydrolysis. Does not cause peeling during storage
When M is Al, propyl, butyl, ethylacetoacetate or acetylacetonate; when M is Si, ethyl or propyl is preferred.

Examples of such a metal element-containing organic compound include aluminum triethoxide and aluminum tri-oxide.
n-propoxide, aluminum triisopropoxide, secondary butoxyaluminum diisopropoxide,
Aluminum tri-n-butoxide, aluminum tri-secondary butoxide, aluminum tri-tert-butoxide, aluminum tris (hexyl oxide), aluminum tris (2-ethylhexyl oxide), aluminum tris (methoxy ethoxide), aluminum tris (ethoxy ethoxy) ) And aluminum tris (butoxyethoxide); and their corresponding tetraalkoxysilanes and tetrakis (alkoxyalkoxy) silanes, which are used as partial (co) hydrolytic condensates as described above.

Further, when M is Al, as described above,
An aluminum chelate compound in which a part or all of OR is an alkyl acetoacetate group and / or an acetylacetonate group can be used. Such compounds include diisopropoxyaluminum methyl acetoacetate, diisopropoxyaluminum ethyl acetoacetate, diisopropoxyaluminum propyl acetoacetate, di-n-butoxyaluminum methyl acetoacetate, di-n-butoxyaluminum ethyl acetoacetate , Isopropoxyaluminum bis (ethylacetoacetate), n-butoxyaluminum bis (ethylacetoacetate), aluminum tris (ethylacetoacetate), acetylacetonatoaluminum bis (ethylacetoacetate) and aluminum tris (acetylacetonate) Is done.

In the partial (co) hydrolytic condensation of the metal element-containing organic compound M (OR) _n , a calculated amount of water is added to the compound, if necessary, in the presence of a solvent such as toluene, and the mixture is stirred. While at room temperature, depending on the hydrolyzability of the compound,
Alternatively, it is possible to proceed to a condensation reaction by partial hydrolysis while heating or cooling. Here, the calculated amount means an amount obtained by subtracting the amount of water generated by condensation from the theoretical amount of water required for partial hydrolysis. This partial (co) hydrolytic condensation is generally carried out before mixing with the phosphor, but may be carried out after the metal element-containing organic compound is blended into the phosphor.

The phosphor particles may be those which emit fluorescence when irradiated with ultraviolet rays. Usually, phosphor particles exhibiting the three primary colors of light, red, green and blue, are used alone or, if necessary, mixed. Used. The average particle size of the phosphor particles is
A range of 1 to 5 μm is preferred.

The above-mentioned metal element-containing compound or a part thereof (co) which is such a phosphor and a binder precursor
The hydrolysis condensate is mixed with a vehicle and a solvent or dispersant to form a paste, applied or printed on a transparent substrate such as glass, and then fired to convert the above condensate into an oxide, thereby forming a phosphor. Form a layer.

As the vehicle, ethyl cellulose, nitrocellulose, acrylic resin and the like can be used.

The solvent or the dispersion medium varies depending on the type of the organic group R of the organic compound containing a metal element, but includes toluene, xylene, ethylbenzene, diethylbenzene, and the like.
Isopropylbenzene, amylbenzene, p-cymene,
Aromatic hydrocarbons such as tetralin and petroleum-based aromatic hydrocarbon mixtures; ether alcohols such as 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether; methyl isobutyl Examples thereof include ketones such as ketones; and esters such as ethylene glycol monomethyl ether acetate, which may be used alone or as a mixture of two or more. Depending on the type of the metal-element-containing organic compound, the partial (co) hydrolytic condensate also has hydrolyzability, so that these solvents or dispersion media are preferably used after being dehydrated.

The amount of the above-mentioned metal element-containing organic compound or a partial (co) hydrolytic condensate thereof, which is a binder precursor, is set to 0.1 to the phosphor particles so as to completely cover the surface of the phosphor particles. It is an amount that gives a metal oxide of 5% by weight or more, and preferably an amount that gives a metal oxide of 1 to 15% by weight.

The amounts of vehicle and solvent or dispersion medium are
Depending on the printing method, conditions and area of the paste, the apparent viscosity of the system is usually 50 to 1,000 dPa · s, preferably 200 dPa · s.
１，1,000 dPa · s as appropriate.

The paste is uniformly printed or coated on a substrate, pre-dried at 150 to 180 ° C.
Bake at 0 ° C. for 5 to 15 minutes. In this way, the phosphor particles form a phosphor layer on the surface of which a uniform thin film of aluminum oxide and / or silicon dioxide or a composite oxide of both is formed. The thickness of the phosphor layer thus formed is preferably about 5 to 20 μm.

The phosphor layer manufactured as described above is provided on the inner surface of the discharge panel, and is set on the discharge panel together with the anode and the cathode. The vacuum annealing process is performed, and a gas is sealed to produce a gas discharge panel. As the filling gas, for example, a mixed gas of Ne and Xe can be used. The pressure of the filling gas is usually from 200 to 500 Torr.

[0023]

The phosphor layer obtained by the present invention has phosphor particles uniformly coated with a thin film of a binder composed of an oxide of aluminum and / or silicon. Therefore, the thin film is transparent to both ultraviolet light and visible light, and the phosphor is sufficiently excited to obtain visible light with high luminance. Further, the thin film is resistant to ion bombardment, and does not cause a decrease in luminance because the phosphor particles are not deteriorated by ion bombardment.

Therefore, according to the present invention, a gas discharge panel having high luminance and long life can be provided.

[0025]

The present invention will be described more specifically with reference to the following examples and comparative examples. The present invention is not limited by these examples. In these examples and comparative examples, all parts are parts by weight.

As the phosphors, three kinds of commercial products shown in Table 1 were used.

[0027]

[Table 1]

Examples 1 to 3 R (Example 1), G (Example 2) or B
Using 100 parts of (Example 3), a calculated amount to give 10 parts of aluminum oxide, and a cyclic trimer obtained by partially hydrolyzing aluminum triisopropoxide were blended and thoroughly mixed. A paste was prepared by mixing and mixing an appropriate amount of a diethylene glycol monobutyl ether solution containing 25% by weight of ethylcellulose so that the apparent viscosity of the system was 500 dPa · s.

This paste was printed on a 1 mm square glass plate and heated and dried at 150 ° C. for 5 minutes to evaporate the solvent.
It was baked at 450 ° C. for 15 minutes to obtain a phosphor layer sample having a structure in which the surfaces of the phosphor particles were coated with a binder made of aluminum oxide.

Examples 4 and 5 R (Example 4) or G (Example 5) was used as the phosphor.
In addition to the above, a calculated amount to give 5 parts of aluminum oxide was used as a binder precursor, and a cyclic trimer obtained by partially hydrolyzing aluminum tri-secondary butoxide was added. Example 1 except that
In the same manner as in the above, a phosphor layer was formed on the panel surface.

Examples 6 to 8 R (Example 6), G (Example 7) or B
(Example 8) 100 parts of aluminum tris (ethyl acetoacetate) was dispersed in 100 parts of toluene and thoroughly stirred and mixed. Then, the mixture was spray-dried at a temperature of 300 ° C to volatilize the toluene, thereby obtaining the mixture. The mixed powder was made into a paste in the same manner as in Example 1, followed by printing and baking to obtain a phosphor layer. The phosphor layer after firing contained 2.1% by weight of aluminum oxide.

Examples 9 and 10 Ethyl orthosilicate and aluminum triisopropoxide were uniformly mixed so that the weight ratio in terms of Al ₂ O ₃ : SiO ₂ was 2: 1. By adding a calculated amount of water and stirring at 40 ° C., a partially hydrolyzed condensate having an average degree of polymerization of 5.1 was obtained. B as phosphor
100 parts of (Example 6) or R (Example 7) were used, and as a binder precursor, the condensate obtained as described above was blended in a calculated amount to give 15 parts of a composite oxide. A phosphor layer was formed on the glass surface in the same manner as in Example 1.

Example 11 A calculated amount of water was added to ethyl orthosilicate while stirring to obtain
By stirring at 5 ° C., ethyl polysilicate having an average degree of polymerization of 5.3 was obtained. A phosphor layer was formed on the glass surface in the same manner as in Example 1 except that 100 parts of G was used as a phosphor, and the above-mentioned ethyl polysilicate was added as a binder precursor in a calculated amount to give 10 parts of silicon dioxide. I let it.

Comparative Examples 1 and 2 100 parts of the phosphor R (Comparative Example 1) or G (Comparative Example 2) were mixed with 10 parts of a lead glass frit having a softening point of 520 ° C., and the mixture contained 25% by weight of ethyl cellulose. An appropriate amount of diethylene glycol monobutyl ether solution was mixed and mixed to prepare a paste having an apparent viscosity of 500 dPa · s. This paste was printed on a 1 mm square glass, air-dried and the solvent was volatilized to obtain a phosphor layer sample.

Comparative Examples 3 and 4 Fluorescent materials were prepared in the same manner as in Comparative Examples 1 and 2, except that the blending amount of lead glass frit with respect to 100 parts of phosphor R (Comparative Example 3) or G (Comparative Example 4) was changed to 1 part. A body layer sample was obtained.

Comparative Examples 5 and 6 The same procedure as in Example 1 was carried out except that the amount of ethyl polysilicate was changed to 100 parts of phosphor R (Comparative Example 5) or G (Comparative Example 6) to give 0.1 parts of silicon dioxide. In the same manner as in No. 11, a phosphor layer was formed.

Comparative Examples 7 to 9 Phosphors R (Comparative Example 7) and G
An appropriate amount of the same ethyl cellulose diethylene glycol monobutyl ether solution as used in Comparative Example 1 was mixed with (Comparative Example 8) or B (Comparative Example 9) and mixed to prepare a paste having a similar apparent viscosity. Using this paste, a phosphor layer sample was obtained in the same manner as in Comparative Example 1.

Evaluation of Fluorescence Intensity For the glass plates on which the phosphor layers were formed in Examples 1 to 11 and Comparative Examples 1 to 9, the fluorescence intensity before and after ion bombardment was measured by the following method. The relative value to the fluorescence intensity before ion bombardment of the comparative example in which the phosphor layer was formed using only the body was obtained. The results were as shown in Table 2.

[0039]

[Table 2]

Fluorescence intensity (before ion bombardment) Ultraviolet rays of 1,800 to 2,200 ° were irradiated in a stream of N ₂ to generate fluorescence. The intensity of the generated fluorescence was measured using a photoelectric tube, and among Comparative Examples 7 to 9, the relative value was calculated with the fluorescence intensity of 100 using the same phosphor.

Fluorescence intensity (after ion bombardment) For the phosphor layer, Journal of Applied Physics, 32
Volume 3, No. 365 (1961), ion bombardment with argon ions was performed. That is, Gd _0.8 Ca is formed by the same method as that for forming the phosphor layer.
_0.2 CrO ₃ 100 parts and SiO ₂ precursor (the same ethyl polysilicate used in Example 11) SiO ₂ conversion 1
5 parts and uniformly coated with Ti were used as a cathode. The glass plate on which the phosphor layer has been formed is placed on the anode with the phosphor layer facing up, and placed in an atmosphere of 5 μmHg argon for 1 k.
An argon ion bombardment of eV was performed.

After the ion bombardment, the fluorescence intensity was measured in the same manner as described above. Of the comparative examples 7 to 9 before the ion bombardment, based on the fluorescence intensities of those using the same phosphor, respectively.
Similar relative values were determined.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01J 9/227 C09K 11/02 C09K 11/08

Claims (2)

(57) [Claims] 1. A method of manufacturing a phosphor layer for a gas discharge panel containing a phosphor and a binder, wherein a precursor of the binder is a general formula M (OR) _n (where M is Al or S
R represents an alkyl group or an alkoxyalkyl group having 2 to 8 carbon atoms which may be the same or different from each other; and n represents a valency of M). A condensate obtained by condensation or partial hydrolysis condensation; or in the above general formula,
The amount of a metal element-containing compound in which M is Al and a part or all of OR is an alkyl acetoacetate group or an acetylacetonate group, which gives an oxide of 0.5% by weight or more with respect to the fluorescent substance, A method for producing a phosphor layer for a gas discharge panel, wherein the phosphor layer is mixed with a body and fired. 2. A method of manufacturing a gas discharge panel having a phosphor layer provided on an inner surface of a discharge panel and having an anode and a cathode, wherein the phosphor layer is manufactured by the method according to claim 1. Manufacturing method of gas discharge panel.