GB2306969A - Fluorescent material comprising an alkali metal gallate - Google Patents
Fluorescent material comprising an alkali metal gallate Download PDFInfo
- Publication number
- GB2306969A GB2306969A GB9623101A GB9623101A GB2306969A GB 2306969 A GB2306969 A GB 2306969A GB 9623101 A GB9623101 A GB 9623101A GB 9623101 A GB9623101 A GB 9623101A GB 2306969 A GB2306969 A GB 2306969A
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- United Kingdom
- Prior art keywords
- water
- fluorescent material
- soluble fluorescent
- alkali
- gallium
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- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
- C03C17/006—Surface treatment of glass, not in the form of fibres or filaments, by coating with materials of composite character
- C03C17/008—Surface treatment of glass, not in the form of fibres or filaments, by coating with materials of composite character comprising a mixture of materials covered by two or more of the groups C03C17/02, C03C17/06, C03C17/22 and C03C17/28
- C03C17/009—Mixtures of organic and inorganic materials, e.g. ormosils and ormocers
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
- C09K11/02—Use of particular materials as binders, particle coatings or suspension media therefor
- C09K11/025—Use of particular materials as binders, particle coatings or suspension media therefor non-luminescent particle coatings or suspension media
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
- C09K11/06—Luminescent, e.g. electroluminescent, chemiluminescent materials containing organic luminescent materials
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
- C09K11/08—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
- C09K11/62—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing gallium, indium or thallium
- C09K11/621—Chalcogenides
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C24/00—Coating starting from inorganic powder
- C23C24/08—Coating starting from inorganic powder by application of heat or pressure and heat
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C30/00—Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Inorganic Chemistry (AREA)
- Composite Materials (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Chemical & Material Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Luminescent Compositions (AREA)
Abstract
A water-soluble fluorescent material, for colour-picture cathode ray tubes (CP-CRT), is represented by the formula: M(x)Ga(y)O(z):A wherein: ```M is an alkali metal cation (lithium, sodium, potassium, rubidium and caesium); ```x and y are from 1 to 5; ```z is from 2 to 8; ```A is a coating material which controls positive charges (preferably selected from ethylcellulose, poly(methylmethacrylate), nigrosine and quaternary ammonium salts). The material, which is preferably of a spinel structure, may further comprise a dyestuff or an activator. A water-soluble flourescent fluidized powder, for CP-CRT, comprises a fluorescent material and a fluid (preferably air or nitrogen). A process for the prepartion of a fluorescent film for CP-CRT comprises: (i) charging a glass panel for CP-CRT onto which a black matrix is provided (preferably by a corona, or triboelectric, procedure); (ii) exposure to light, through a mask, to eliminate charges on a selected region of the said glass panel; (iii) dispersal of positively-charged water-soluble fluorescent fluidized powder onto said exposed glass panel; (iv) drying of said dispersed powder: thereby to form a fluorescent layer on said glass panel.
Description
A WATER-SOLUBLE FLUORESCENT MATERIAL
FOR COLOUR PICTURE TUBES
AND A PROCESS FOR MANUFACTURING THE SAME Fleld of the Invention
This invention relates to a fluorescent material for colour CRT, more particularly to a fluorescent material for colour CRT which increases luminous efficiency of a fluorescent layer for colour CRT and decreases a current value according to an electron beam in a luminance of the same fluorescent layer to increase resolution according to an electron beam spot reduction, by the introduction of a dry process which does not use water but uses a water soluble material with excellent luminous efficiency in Braun tube screens.
Descnption of the Pnor Art
A fluorescent layer of a cathode ray tube (CRT) is where energy of electron beams is charged to photoenergy. As shown in Figure 1, electrons are luminous by collision with fluorescent materials of a fluorescent film (8) formed on a panel (11) on the opposite side of an observer, and properties of the fluorescent layer depend greatly on the properties of the fluorescent material.
In general, fluorescent materials used in a fluorescent layer for colour picture tubes (CPT) are produced by adding a small amount of one or more impurities known as activators to a base body such as zinc sulfide or yttrium oxide, etc., and calcinating for 30 minutes to 1 hour at a temperature of 700 - 1300 C. The above activators are copper (Cu), gold (Au), rare earth elements, etc.
A process for manufacturing a fluorescent film for colour picture tubes consists of the steps of coating a photoresist on the inside of a panel, exposing to light, developing, graphite coating, etching, and forming graphite stripes to form black matrices (BM), by photolithography.
A step of forming a fluorescent film is as follows. A fluorescent slurry composition is prepared by suspending fluorescent materials in a solution of poly vinyl alcohol (PVA) and ammonium dichromate (ADC) through a slurry method.
The fluorescent slurry composition (22) is coated inside of the panel (1 1) through a nozzle (21) while the panel revolves, the panel is dried by an infrared heater, a shadow mask is deposited to solidify a photosensitive layer formed inside of the panel by exposure to Lw light and the layer is developed with water to form a fluorescent material pattern.
Subsequently, an aluminium film is formed by coating the fluorescent layer between black matrices inside of the panel, filming to form an organic film, and depositing aluminium.
Organic materials remaining on the fluorescent layer are removed by heat treatment.
As indicated in the above, a fluorescent screen is formed by exposing Lw to a photosensitive coating layer, which consists of fluorescent materials, polyvinyl alcohol, ammonium dichromate, water and interfacial active agent, etc. However, substantially, photosensitivity mechanism is proceeded by polyvinyl alcohol, ammonium dichromate and water. A mechanism for formation of a fluorescent layer is divided into a dark reaction and a light reaction.
A dark reaction means the oxidation-reduction reaction occurring between polyvinyl alcohol and ammonium dichromate in the fluorescent material slurrv.
A light reaction means a reaction in which, after breakage of chains of polyvinyl alcohol, polyvinyl alcohol cross-links by C+ ions reduced from Cr6+.
Consequentially, in this reaction, solubility of polyvinyl alcohol for water is decreased.
Because water is used in the photoreaction, insufficient water on the coating layer inhibits the reaction. Conversely, extra water inhibits three-dimensional crosslinking.
C+ which is produced in the photoreaction and acquired in this reaction again, is reacted with water by competitive reaction to form a stable compound.
However, this compound does not contribute to cross-linking. The product can be obtained under the condition that pertinent moisture be maintained on the fluorescent layer during the light reaction.
A picture is acquired by illuminating fluorescent materials coating the interior surface of a panel (11), by energy due to electron beams from an electron gun in
Figure 1. In the above process, the coating process consists of pouring fluorescent materials, of aqueous solution for coating, exposing to light after precipitating fluorescent materials, hardening and washing, sequentially. In the event that the fluorescent material is soluble in water, it has drawbacks of not being precipitated and facile to drive off at washing. The fluorescent material must not react with water in order to preserve its characteristics. Accordingly, water-soluble fluorescent material has been excluded from consideration even if it has distinguished fluorescent efficiency, colour coordinates, time of afterglow, etc.
Summarv of the Invention
An object of the present invention is to elevate luminance and visibility of colour picture tubes, through a dry filming process by the use of a water-soluble fluorescent material which has been excluded from conventional colour picture tubes.
The present invention provides a water-soluble fluorescent material for colour picture tubes represented by the formula (I): MGayO : A (I) wherein M is an alkali metal, x = 1-5, y = 1-5, z = 2-8, and A is a coating material to control positive charges.
Preferably, the material is doped with component A in an amount of from about 0.1% by weight to about 5% by weight.
It is also preferred that the coating material be selected from the group consisting of ethylcellulose, polymethylmethacrylate, nigrosine, and quaternary ammonium salts.
The alkali metal is preferred to be selected from the group consisting of lithium, sodium, potassium, rubidium, and cesium. Preferably, the water-soluble fluorescent material has a spinel structure.
The present invention further provides a process for the preparation of a water-soluble fluorescent material for colour picture tubes comprising the step of heating an alkali-metal gallium sulphate (MGa(SO4).nH2O) in the atmosphere.
The process of the invention can further include the steps of mixing alkalimetal gallium oxide (MGaO2( 1)) and a gallium dispersed liquid and evaporating the mixture solution of alkali-metal gallium oxide and the gallium dispersed liquid and coprecipitating the evaporated mixture solution.
Also the present invention provides a process comprising the steps of mixing gallium hydroxide (Ga(OH)3) in the form of a gel and alkali-metal hydroxide (M(OH)) and dehydrating abruptly the mixture solution of gallium hydroxide and alkali-metal hydroxide at a temperature of 300 - 500"C.
This invention provides a water-soluble fluorescent fluidized powder for colour picture tubes comprising a fluorescent material and a fluid.
Preferably, the fluorescent material is water soluble and is represented by formula (I): MGayO : A (I) wherein M is an alkali metal, x = 1-5, y = 1-5, z = 2-8, and A is a coating material to control positive charges.
Preferably, the material is doped with component A in an amount of from about 0. 1% by weight to about 5% by weight.
It is also preferred that the coating material be selected from the group consisting of ethylcellulose, polymethylmethacrylate, nigrosine, and quaternary ammonium salts.
The alkali metal is preferred to be selected from the group consisting of lithium, sodium, potassium, rubidium, and cesium. and the water-soluble fluorescent material is preferred further to comprise a dye or an activator. The fluid is preferred to be air or nitrogen.
This invention provides a process for the preparation of a fluorescent layer for colour picture tubes comprising the steps of charging a glass panel for a colour picture tube on which a black matrix is formed, exposing to light through a mask to drive off the charges on the selective region of the glass panel, and dispersing positively-charged water-soluble fluorescent fluidized powder to the exposed glass panel.
The charging is corona charging and the fluidized powder is comprised of a water-soluble fluorescent material and a fluid.
The present invention provides a process for the preparation of a fluorescent film for colour picture tubes, in which a water-soluble material is represented by formula (I): MxGayOz: A (I) wherein, M is an alkali metal, x = 1-5, y = 1-5, z = 2-8, and A is a coating material to control positive charges.
Preferably, the material is doped with component A in an amount of from about 0.1% by weight to about 5% by weight.
It is also preferred that the coating material be selected from the group consisting of ethylcellulose, polymethylmethacrylate, nigrosine, and quaternary ammonium salts.
The above alkali metal is preferred to be selected from the group consisting of lithium, sodium, potassium, rubidium, and cesium. The water-soluble fluorescent material is preferably further comprised of a dye or an activator and preferably has a spinel structure.
The process comprises the step of heating alkali metal gallium sulphate (MGa(SO4).nH2O) in the atmosphere, or the steps of mixing alkali metal gallium oxide (MGaO2( 1)) and gallium dispersed liquid, evaporating the mixture solution of alkali metal gallium oxide and the gallium dispersed liquid and coprecipitating the evaporated mixture solution.
Additionally the process may be comprise of the @@eps of mixing galiium hydroxide (Ga(OH)3) in the form of a gel and alkali-metal hydroxide (M(OH)) and dehydrating abruptly the mixture solution of gallium hydroxide and the alkali-metal hydroxide at a temperature of 300 - 500"C.
The fluid is preferred to be air or nitrogen.
Brief Description of the Drawings
Figure 1 illustrates a colour picture tube briefly;
Figure 2 is a simplified illustration showing the coating process for a conventional fluorescent composition for colour picture tubes;
Figure 3 is a simplified illustration showing the coating process for a watersoluble fluorescent composition for colour tubes according to the present invention;
Figure 4 displays briefly an internal state after exposure to light of a glass panel for colour picture tubes, which is positively charged;
Figure 5 is a protocol for a fluorescent layer of colour picture tubes according to the present invention; and
Figure 6 is a protocol showing a manufacturing process for a fluorescent film of colour picture tubes according to the present invention.
The following are presented as Examples but do not limit the scope of the invention.
Example 1
Preparation of water-soluble fluorescent matenal in lithium gallate svstem.
100g of LiGa(SO4)2.nH2O was heated in the atmosphere to produce a watersoluble fluorescent material, LiGaO2. This material was doped with 1% by weight of ethylcellulose to control positive charges.
Preparation of a fluorescent film for colour picture tubes
The protocol of a manufacturing process for a fluorescent film for colour picture tubes is shown in Figure 6.
Layers of a conductive material (41) were constructed on a washed glass panel for colour picture tubes, a photoconductive material (42) was built thereon, the layer was corona-charged, and exposed to light through a shadow mask. Three exposures are required at this time from three different lamp positions to discharge the areas of photoconductor.
Sequential development of the black matrix by the method of electrophotography using liquid toner for black matrix is executed.
50 g of powdered fluorescent material, LiGaO2.M (M is an activator) (36) in lithium gallate system obtained as above were sent to a feeder through an injector of a fluorescent material powder tank (37), the powder (36) was transferred to an amount-controlling valve (35) of a fluorescent material through a screw guided by revolution of a motor. By opening and shutting off the amount-controlling valve of fluorescent material, the concentration of a fluid supplied through the amountcontrolling valve and the powder fluorescent material was adjusted to 5 g/m3. The water-soluble fluorescent material in the form of a powder was dispersed in the fluid composed of air or nitrogen to give a fluidized powder which was supplied to a dispersion gun (33), and the fluorescent material was charged positively.
Fluorescent fluidized powder material was constructed in layers and fixed on uncharged areas of an interior panel where a latent charge image is established. The above processes of corona charging, exposure, development and fixing were carried out three times in the order of red, green and blue fluorescent materials to obtain water-soluble fluorescent layers for colour picture tubes.
Example 2
Substantially the same process as Example 1 was carried out except that 5g of Ga was added to 11 of LiGaO2 solution, evaporated and coprecipitated to produce the water-soluble fluorescent material LiGaO2, which was doped with 1% by weight of ethylcellulose to control positive charges.
Example 3
Substantially the same process as Example 1 was carried out to obtain a water-soluble fluorescent material, LiGaO2, except that Ga(OH)3 in the form of a gel was added to Li(OH) solution and dehydrated abruptly at a temperature of 400 "C to produce the water soluble fluorescent material LiGaO2, which was doped with 1% by weight of ethylcellulose to control positive charges.
Comparative Example 4
Substantially the same process as Example 1 was carried out except that the water-soluble fluorescent material LiGaO, was not doped with a coating material to control positive charges.
Example 5
Substantially the same process as Example 1 was carried out except that the water-soluble fluorescent material LiGaO2 was doped with polymethylmethacrylate to control positive charges.
Example 6
Substantially the same process as Example 1 was carried out except that the water-soluble fluorescent material LiGaO2 was doped with nigrosine to control positive charges.
Example 7
Substantially the same process as Example 1 was carried out except that the water-soluble fluorescent material LiGaO2 was doped with a quaternary ammonium salt to control positive charges.
Comparative Example 8
A washed glass panel for colour picture tubes was dried, coated with a photoresist, dried, exposed to light, and washed to remove unreacted photoresist.
Graphite was coated on the panel, dried and washed with hydrogen peroxide to construct a black matrix. A fluorescent slurry of ZnS.CuAl was coated on the panel, on which the black matrix shown in Figure 2 is formed through a nozzle (21), and drying, exposure, and drying were carried out to prepare a fluorescent layer indicated in Figure 5. A relative luminance was measured to evaluate the properties of the fluorescent layers in Examples 1 to 3, 5 to 7 and Comparative Examples 4 and 8.
The relative luminances prepared in the Examples 1 to 8 were as follows:
Chemical Formula Relative Luminance Example 1 LiGaO2:ethylcellulose 131 Example 2 LiGaO2 :ethylcellulose 125 Example 3 LiGaO2:ethylcellulose 127 Comparative LiGaO2 85 Example 4 (no coating material to control positive charges) Example 5 LiGaO2:PMMA 130 Example 6 LiGaO2:nigrosine 125 Example 7 LiGaO2::quaternary 125 ammonium salt Comparative ZnS.CuA1 100 Example 8 The luminance in 14" CDT (colour display tube) at Ik = 500A of Example 3 and the Comparative Example 8 were 88 Ft-L and 69 Ft-L, respectively.
Therefore the fluorescent material according to the present invention had higher luminance than conventional fluorescent materials.
The relative luminance of the water soluble fluorescent layer according to
Comparative Example 4 was lower than that of the layer according to Comparative
Example 8 because the fluorescent layer according to Comparative Example 4 was not doped with enough fluorescent material owing to a little charges.
The present invention provides a fluorescent layer with excellent luminance from water-soluble gal late fluorescent material with notable luminance characteristics obtained by the process outlined in Figure 6 in which electrophotographic dry screening process for laser printers has been applied to the preparation of the colour CRT screen.
The fluorescent material according to this invention is an alkali gallate fluorescent material having the empirical formula MxGyOz (M is Li, Na, K, Rb, Cs), and in general Li5GaO4, LiGaO2, LiGaO8, MGaO2 (M: alkali metal) have been used.
The developing process according to this invention is carried out by positivecharging by corona charging on glass panel with black matrix for colour picture tubes and exposure to light. A water-soluble fluorescent fluidized powder was prepared as follows.
First, a certain amount of fluorescent material in the form of a powder is put into an injector of a tank for powdered fluorescent material, powdered fluorescent material is sent to an amount-controlling valve of fluorescent material through a screw guided by revolution of a motor. By opening and shutting off the amountcontrolling valve of fluorescent material, the fluorescent material and a fluid supplied through the amount-controlling valve, for example air and nitrogen, are mixed in a desired ratio. After being mixed, the fluorescent fluidized powder is supplied to a dispersion gun. The apparatus for triboelectrically or corona charging is mounted on it to obtain a positively-charged fluorescent fluidized powder.
Accordingly, positively-charged fluorescent fluidized powder is dispersed through an injector onto an interior panel and a latent charge image is formed as indicated in Figure 4, to be accumulated on uncharged areas by the repulsion of charges.
Claims (22)
1. A water-soluble fluorescent material for colour picture tubes represented by the formula (I) MxGayOz: A (I) where M is an alkali metal, x = 1-5, y = 1-5, z = 2-8, and A is a coating material to control positive charges.
2. A water-soluble fluorescent material according to claim 1, doped with component A in an amount of from about 0. 1% by weight to about 5% by weight.
3. A water-soluble fluorescent material according to claim 1 or claim 2, wherein the coating material is selected from the group consisting of ethylcellulose, polymethylmethacrylate, nigrosine, and quaternary ammonium salts.
4. A water-soluble fluorescent material according to any one of claims l to 3, wherein said alkali metal is selected from the group consisting of lithium, sodium, potassium, rubidium, and cesium.
5. A water-soluble fluorescent material according to any one of claims 1 to 4, wherein said water-soluble fluorescent material has a spinel structure.
6. A water-soluble fluorescent material according to any one of of claims 1 to 5, further comprising a dye or activator.
7. A process for the preparation of a water-soluble fluorescent material according to anyone of claims 1 to 6, including the step of heating an alkali-metal gallium sulphate (MGa(SO4).nH2O) in the atmosphere.
8. A process for the preparation of a water-soluble fluorescent material according to any one of claims 1 to 6, including the steps of:
mixing an alkali-metal gallium oxide (MGaO2( 1)) and a gallium dispersed liquid;
evaporating the mixture of the alkali-metal gallium oxide and the gallium dispersed liquid; and
coprecipitating the evaporated mixture.
9. A process for the preparation of a water-soluble fluorescent material according to any one of claims 1 to 6, including the steps of:
mixing gallium hydroxide (Ga(OH)3) in the form of a gel and an alkali-metal hydroxide (M(OH)); and
dehydrating abruptly the mixture of the gallium hydroxide and the alkalimetal hydroxide at a temperature of 300 - 500"C.
10. A water-soluble fluorescent fluidized powder for colour picture tubes comprising a fluorescent material and a fluid.
11. A water-soluble fluorescent fluidized powder according to claim 10, wherein said water-soluble fluorescent material is a material according to any one of claims 1 to 6.
12. A water-soluble fluorescent fluidized powder according to claim 10 or claim 11, wherein said fluid is air or nitrogen.
13. A process for the preparation of a fluorescent film for colour picture tubes comprising the steps of:
charging a glass panel for colour picture tubes on which a black matrix is formed;
exposing to light through a mask to eliminate charges on a selected region of the glass panel; and
dispersing positively-charged water-soluble fluorescent fluidized powder to the exposed glass panel and drying to form a fluorescent layer.
14. A process according to claim 12, wherein the charging is corona charging or triboelectric charging.
15. A process according to claim 13 or claim 14, wherein said positive charged water-soluble fluorescent fluidized powder is comprised of a water-soluble fluorescent material and a fluid.
16. A process according to claim 15, wherein said water-soluble fluorescent material is a material according to any one of claims 1 to 6.
17. A process according to any one of claims 13 to 16, further comprising the step of heating an alkali-metal gallium sulphate (MGa(SO4).nH2O) in the atmosphere.
18. A process according to any one of claims 13 to 16, further comprising the steps of:
mixing an alkali-metal gallium oxide MGaO2( 1)) and a gallium dispersed liquid;
evaporating the mixture of the alkali-metal gallium oxide and the gallium dispersed liquid; and
coprecipitating the evaporated mixture.
19. A process according to any one of claims 13 to 16, further comprising the steps of:
mixing gallium hydroxide (Ga(OH)3) in the form of a gel and an alkali-metal hydroxide (M(OH)); and
dehydrating abruptly the mixture of gallium hydroxide and the alkali-metal hydroxide at a temperature of 300 - 500"C.
20. A process according to any one of claims 13 to 19, wherein said fluid is air or nitrogen.
21. A water-soluble fluorescent material for colour picture tubes substantially as described herein with reference to any of Examples 1 to 3 and 5 to 7.
22. A process for the preparation of a water-soluble fluorescent material for colour picture tubes substantially as described herein with reference to any of
Examples 1 to 3 and 5 to 7.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR19950040107 | 1995-11-07 | ||
| GBGB9600868.5A GB9600868D0 (en) | 1995-11-07 | 1996-01-16 | A water-soluble fluorescent material for colour picture tubes and a process for manufacturing the same |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB9623101D0 GB9623101D0 (en) | 1997-01-08 |
| GB2306969A true GB2306969A (en) | 1997-05-14 |
| GB2306969B GB2306969B (en) | 1999-02-03 |
Family
ID=26308470
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9623101A Expired - Fee Related GB2306969B (en) | 1995-11-07 | 1996-11-05 | A water-soluble fluorescent material for colour picture tubes and a process for manufacturing the same |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2306969B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1086555A (en) * | 1963-12-19 | 1967-10-11 | Western Electric Co | Electrical devices with bodies of crystalline material |
| GB1224130A (en) * | 1968-12-13 | 1971-03-03 | Philips Electrical And Associa | Improvements relating to luminescent materials |
| GB1279151A (en) * | 1968-06-14 | 1972-06-28 | Gte Sylvania Inc Formerly Know | Phosphor compositions |
| GB1439220A (en) * | 1972-11-03 | 1976-06-16 | Philips Electronic Associated | Luminescent materials |
-
1996
- 1996-11-05 GB GB9623101A patent/GB2306969B/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1086555A (en) * | 1963-12-19 | 1967-10-11 | Western Electric Co | Electrical devices with bodies of crystalline material |
| GB1279151A (en) * | 1968-06-14 | 1972-06-28 | Gte Sylvania Inc Formerly Know | Phosphor compositions |
| GB1224130A (en) * | 1968-12-13 | 1971-03-03 | Philips Electrical And Associa | Improvements relating to luminescent materials |
| GB1439220A (en) * | 1972-11-03 | 1976-06-16 | Philips Electronic Associated | Luminescent materials |
Also Published As
| Publication number | Publication date |
|---|---|
| GB9623101D0 (en) | 1997-01-08 |
| GB2306969B (en) | 1999-02-03 |
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| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |