GB2032451A - Process for Preparing a Pigment-carrying Red-luminescent Phosphor - Google Patents
Process for Preparing a Pigment-carrying Red-luminescent Phosphor Download PDFInfo
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- GB2032451A GB2032451A GB7932450A GB7932450A GB2032451A GB 2032451 A GB2032451 A GB 2032451A GB 7932450 A GB7932450 A GB 7932450A GB 7932450 A GB7932450 A GB 7932450A GB 2032451 A GB2032451 A GB 2032451A
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- phosphor
- salt
- ferric
- process according
- iron
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- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 title claims abstract description 92
- 238000004519 manufacturing process Methods 0.000 title claims description 7
- 238000000034 method Methods 0.000 claims abstract description 30
- 239000000049 pigment Substances 0.000 claims abstract description 24
- 239000007864 aqueous solution Substances 0.000 claims abstract description 20
- 150000002505 iron Chemical class 0.000 claims abstract description 11
- 150000002506 iron compounds Chemical class 0.000 claims abstract description 11
- 239000001054 red pigment Substances 0.000 claims abstract description 7
- 150000001875 compounds Chemical class 0.000 claims abstract description 3
- -1 europium-activated yttrium oxide Chemical class 0.000 claims abstract description 3
- 239000002994 raw material Substances 0.000 claims description 29
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical group [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 claims description 18
- 239000002245 particle Substances 0.000 claims description 16
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 12
- 238000006243 chemical reaction Methods 0.000 claims description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 11
- 150000003839 salts Chemical class 0.000 claims description 10
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims description 8
- 238000001354 calcination Methods 0.000 claims description 8
- 229960004887 ferric hydroxide Drugs 0.000 claims description 7
- WBJZTOZJJYAKHQ-UHFFFAOYSA-K iron(3+) phosphate Chemical compound [Fe+3].[O-]P([O-])([O-])=O WBJZTOZJJYAKHQ-UHFFFAOYSA-K 0.000 claims description 7
- IEECXTSVVFWGSE-UHFFFAOYSA-M iron(3+);oxygen(2-);hydroxide Chemical compound [OH-].[O-2].[Fe+3] IEECXTSVVFWGSE-UHFFFAOYSA-M 0.000 claims description 7
- 229910052742 iron Inorganic materials 0.000 claims description 5
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical group [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 claims description 4
- 239000005955 Ferric phosphate Substances 0.000 claims description 4
- 229940032958 ferric phosphate Drugs 0.000 claims description 4
- 229910000399 iron(III) phosphate Inorganic materials 0.000 claims description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 3
- 229940116007 ferrous phosphate Drugs 0.000 claims description 3
- 229910000398 iron phosphate Inorganic materials 0.000 claims description 3
- 229910000155 iron(II) phosphate Inorganic materials 0.000 claims description 3
- SDEKDNPYZOERBP-UHFFFAOYSA-H iron(ii) phosphate Chemical compound [Fe+2].[Fe+2].[Fe+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O SDEKDNPYZOERBP-UHFFFAOYSA-H 0.000 claims description 3
- 230000001590 oxidative effect Effects 0.000 claims description 3
- 239000001301 oxygen Substances 0.000 claims description 3
- 229910052760 oxygen Inorganic materials 0.000 claims description 3
- 229910019142 PO4 Inorganic materials 0.000 claims description 2
- 229940005991 chloric acid Drugs 0.000 claims description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 claims description 2
- 239000010452 phosphate Substances 0.000 claims description 2
- 238000009877 rendering Methods 0.000 claims 2
- 229920003169 water-soluble polymer Polymers 0.000 abstract description 3
- 229910052693 Europium Inorganic materials 0.000 abstract 1
- 239000011230 binding agent Substances 0.000 abstract 1
- XTQHKBHJIVJGKJ-UHFFFAOYSA-N sulfur monoxide Chemical compound S=O XTQHKBHJIVJGKJ-UHFFFAOYSA-N 0.000 abstract 1
- LSGOVYNHVSXFFJ-UHFFFAOYSA-N vanadate(3-) Chemical compound [O-][V]([O-])([O-])=O LSGOVYNHVSXFFJ-UHFFFAOYSA-N 0.000 abstract 1
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical class [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 12
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 9
- 239000000203 mixture Substances 0.000 description 9
- 239000000243 solution Substances 0.000 description 8
- VCJMYUPGQJHHFU-UHFFFAOYSA-N iron(3+);trinitrate Chemical compound [Fe+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O VCJMYUPGQJHHFU-UHFFFAOYSA-N 0.000 description 7
- 238000001914 filtration Methods 0.000 description 5
- 229910000359 iron(II) sulfate Inorganic materials 0.000 description 5
- 239000000725 suspension Substances 0.000 description 5
- 238000013019 agitation Methods 0.000 description 4
- 239000012736 aqueous medium Substances 0.000 description 4
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- 239000011790 ferrous sulphate Substances 0.000 description 3
- 235000003891 ferrous sulphate Nutrition 0.000 description 3
- 238000002360 preparation method Methods 0.000 description 3
- 238000004381 surface treatment Methods 0.000 description 3
- BZSXEZOLBIJVQK-UHFFFAOYSA-N 2-methylsulfonylbenzoic acid Chemical compound CS(=O)(=O)C1=CC=CC=C1C(O)=O BZSXEZOLBIJVQK-UHFFFAOYSA-N 0.000 description 2
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 2
- QGZKDVFQNNGYKY-UHFFFAOYSA-N ammonia Natural products N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 239000004816 latex Substances 0.000 description 2
- 229920000126 latex Polymers 0.000 description 2
- 229920000642 polymer Polymers 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- 229910016876 Fe(NH4)2(SO4)2 Inorganic materials 0.000 description 1
- 229910016874 Fe(NO3) Inorganic materials 0.000 description 1
- 229910002588 FeOOH Inorganic materials 0.000 description 1
- 108010010803 Gelatin Proteins 0.000 description 1
- 229910021578 Iron(III) chloride Inorganic materials 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 229940010514 ammonium ferrous sulfate Drugs 0.000 description 1
- XGGLLRJQCZROSE-UHFFFAOYSA-K ammonium iron(iii) sulfate Chemical compound [NH4+].[Fe+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O XGGLLRJQCZROSE-UHFFFAOYSA-K 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- BNIILDVGGAEEIG-UHFFFAOYSA-L disodium hydrogen phosphate Chemical compound [Na+].[Na+].OP([O-])([O-])=O BNIILDVGGAEEIG-UHFFFAOYSA-L 0.000 description 1
- 238000000295 emission spectrum Methods 0.000 description 1
- IMBKASBLAKCLEM-UHFFFAOYSA-L ferrous ammonium sulfate (anhydrous) Chemical compound [NH4+].[NH4+].[Fe+2].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O IMBKASBLAKCLEM-UHFFFAOYSA-L 0.000 description 1
- 229960002089 ferrous chloride Drugs 0.000 description 1
- 229920000159 gelatin Polymers 0.000 description 1
- 239000008273 gelatin Substances 0.000 description 1
- 235000019322 gelatine Nutrition 0.000 description 1
- 235000011852 gelatine desserts Nutrition 0.000 description 1
- NMCUIPGRVMDVDB-UHFFFAOYSA-L iron dichloride Chemical compound Cl[Fe]Cl NMCUIPGRVMDVDB-UHFFFAOYSA-L 0.000 description 1
- 239000001034 iron oxide pigment Substances 0.000 description 1
- RBTARNINKXHZNM-UHFFFAOYSA-K iron trichloride Chemical compound Cl[Fe](Cl)Cl RBTARNINKXHZNM-UHFFFAOYSA-K 0.000 description 1
- RUTXIHLAWFEWGM-UHFFFAOYSA-H iron(3+) sulfate Chemical compound [Fe+3].[Fe+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O RUTXIHLAWFEWGM-UHFFFAOYSA-H 0.000 description 1
- 229910000360 iron(III) sulfate Inorganic materials 0.000 description 1
- FLTRNWIFKITPIO-UHFFFAOYSA-N iron;trihydrate Chemical compound O.O.O.[Fe] FLTRNWIFKITPIO-UHFFFAOYSA-N 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 239000007800 oxidant agent Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 229920000036 polyvinylpyrrolidone Polymers 0.000 description 1
- 239000001267 polyvinylpyrrolidone Substances 0.000 description 1
- 235000013855 polyvinylpyrrolidone Nutrition 0.000 description 1
- VKJKEPKFPUWCAS-UHFFFAOYSA-M potassium chlorate Chemical compound [K+].[O-]Cl(=O)=O VKJKEPKFPUWCAS-UHFFFAOYSA-M 0.000 description 1
- 239000011541 reaction mixture Substances 0.000 description 1
- 239000001488 sodium phosphate Substances 0.000 description 1
- RYFMWSXOAZQYPI-UHFFFAOYSA-K trisodium phosphate Chemical compound [Na+].[Na+].[Na+].[O-]P([O-])([O-])=O RYFMWSXOAZQYPI-UHFFFAOYSA-K 0.000 description 1
- 229910000406 trisodium phosphate Inorganic materials 0.000 description 1
- 235000019801 trisodium phosphate Nutrition 0.000 description 1
- ASTWEMOBIXQPPV-UHFFFAOYSA-K trisodium;phosphate;dodecahydrate Chemical compound O.O.O.O.O.O.O.O.O.O.O.O.[Na+].[Na+].[Na+].[O-]P([O-])([O-])=O ASTWEMOBIXQPPV-UHFFFAOYSA-K 0.000 description 1
Classifications
-
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Luminescent Compositions (AREA)
Abstract
A red-luminescent phosphor is dispersed in an aqueous solution of a divalent or trivalent iron salt or iron compound and said iron salt or compound is converted to a water- insoluble iron compound by changing the pH of the aqueous solution or by other processes, thereby to incorporate the water-insoluble iron compound in the phosphor. The phosphor is then calcined to convert this water-insoluble iron compound to a red pigment, and form a pigment- carrying red-luminescent phosphor. In this way, a pigment can be bonded to a phosphor without using a water- soluble polymeric compound or other binder. The phosphor is preferably a europium-activated yttrium oxide, oxysulphide or vanadate for use in a colour CRT.
Description
SPECIFICATION
Process for Preparing a Pigment-carrying Redluminescent Phosphor
The present invention relates to a process for preparing a pigment-carrying red-iuminescent phosphor and to a phosphor prepared by the process.
S. A. Lipp (Japanese Laid-Open Patent
Application No. 56146/75) and G. S. Lozier and
P. B. Branin (Japanese Laid-Open Patent
Application No. 109488/77) have proposed that a phosphor having a pigment adhering to it is used for the fluorescent screen of a color cathoderay tube. When a fluorescent screen is made using a phosphor including particles of a pigment which absorbs rays outside the emission spectrum region of the phosphor, i.e. color filter particles, a color cathode-ray tube having high contrast can be obtained.
In one conventional process for the preparation of such a phosphor having a pigment adhering to it, the pigment and the phosphor are separately prepared and pigment particles are attached to the surfaces of phosphor particles by means of a water soluble polymeric compound such as gelatin or polyvinylpyrrolidone. In another conventional process, colloidal particles of a latex are adsorbed on a phosphor, a pigment is supplied thereto to form a mixture and the mixture is solidified in an aqueous medium by changing the pH of the aqueous medium or by another technique.
In each of these known processes, the pigment is applied to the phosphor by use of a polymeric compound. This means that the handling or processing of these pigment carrying phosphors is limited to a greater or lesser extent.
It is often required to subject a pigmentcarrying phosphor to surface treatment so as to improve its dispersibility and adhesiveness. The surface treatment is ordinarily carried out in an aqueous medium. A phosphor of this kind prepared by use of a water-soluble polymeric compound thus has the defect that in such a surface treatment the pigment is readily separated from the phosphor. Also with a pigment-carrying phosphor prepared by use of colloidal latex particles such treatment is allowed only to the extent that the coagulated colloidal particles are not affected by the treatment.
Another disadvantage is that both of these conventional processes for the preparation of pigment-adhering phosphors involves complicated process steps.
According to the present invention there is provided a process for preparing a pigmentcarrying red-luminescent phosphor, which comprises incorporating a raw material capable of being converted to a red pigment by calcination in a red-luminescent phosphor and thereafter calcining the raw material containing phosphor to convert the raw material into a red pigment.
By the present invention it is possible to provide a process for the preparation of redluminescent phosphors which contain a pigment but contain no polymeric compound.
The raw material for the pigment may be for example ferric hydroxide, ferric oxyhydrate, triiron tetroxide, ferrous phosphate or ferric phosphate.
Any red-luminescent phosphor which is not changed by calination, such as Y2O2S:Eu, Y203:Eu and YvO4, can be used in the invention.
Typically, therefore, a raw material in the form of an iron oxide, which is capable of being converted to a red pigment, is applied to the redluminescent phosphor by dissolving a divalent or trivalent iron salt or iron compound in an aqueous medium containing the dispersed phosphor and then converting the iron salt or compound to the water-insoluble raw pigment material by changing the pH or by some other techniques.
These steps are not necessarily conducted in the order given above. For example, the phosphor may be dispersed in an aqueous solution of the iron salt. In short, it is only required that the conversion of the water-soluble iron salt to the insoluble raw material should occur in the presence of the phosphor. When ferric hydroxide or the like is formed by this reaction, the reaction mixture may be kept in the sol state for a certain short period of time, and the phosphor may be added to the mixture in this state, i.e. after completion of the conversion reaction. In this way, also the insoluble raw material of the pigment can be applied to the phosphor. For ease in determining reaction conditions, it is preferred that the formation of the insoluble raw material is carried out in the presence of the phosphor.
Methods for performing this reaction will now be described in detail.
In one such method, aqueous ammonia or an alkali such as potassium hydroxide or sodium hydroxide is added to an aqueous solution of a ferric salt to render the solution alkaline, preferably to a pH in the range of about 10 to about 11 , to form ferric hydroxide [Fe(OH)3].
In another method, an aqueous solution of a ferrous salt is oxidized by aqueous hydrogen peroxide to form ferric oxyhydrate (Fe99ij).
Alternatively an aqueous solution of a ferrous salt is made alkaline and the ferrous salt is converted to ferric oxyhydrate by blowing sufficient oxygen into the solution or by feeding an oxidant such as aqueous hydrogen peroxide to the solution.
In yet another possible method, an aqueous solution of a ferrous salt is made alkaline, is
preferably heated and is oxidized by a chloric acid
compound such as sodium chlorate or potassium chlorate to convert the ferrous salt to tri-iron tetroxide (Fe3O4). Whether ferric oxyhydrate or triiron tetroxide is prepared depends on the
reaction conditions. In the present invention,
either of these oxidation products can be used.
Another method is one in which a phosphate
such as trisodium phosphate or disodium
hydrogenphosphate is added to an aqueous -solution of a ferrous or ferric salt to convert the salt to an iron phosphate, i.e. ferrous phosphate and/or ferric phosphate.
The ferric or ferrous salt or iron compound used in such processes of the present invention, can be for example ammonium ferrous sulfate [Fe(NH4)2(SO4)2 . 6H20], ferrous chloride (FeCI2 . 4H20), ammonium ferric sulfate (FeNH4(SO4)2 . 1 2H20), ferric chloride (FeCI2. 6H20), ferric nitrate [Fe(NO3)3 . 9H20] or ferric sulfate [Fe2(SO)4)3 . xH2Oj.
The phosphor containing the insoluble raw material is calcined, preferably at 300 to 6000C more preferably at 400 to 5000 C, to form the pigment carrying phosphor. If the temperature of conversion of the raw material to the iron oxide pigment is too low, the hue of the resulting pigment is poor. Accordingly, the calcination temperature is preferably 3000C or higher. In order to obtain an excellent hue, it is preferred that calcination be carried out at a temperature not lower than 4000C. At too high a temperature, the phosphor itself may deteriorate. It is preferred that the calcination temperature be not higher than 6000C, more preferably not higher than 5000C. In the production of a color cathode-raytube, frit baking is carried out at a temperature of 380 to 4500C.Therefore, it is convenient if redluminescent phosphor dots or stripes are formed on the surface of a fluorescent screen of a color cathode-ray tube using the pigment raw material containing phosphor and the raw material is calcined and converted to the pigment in the frit baking.
The amount of the raw material applied to the phosphor is preferably chosen according to the particle size of the phosphor. When the average particle size of the phosphor is in the range of about 6 to about 10 4m, it is preferred that the raw material be applied to the phosphor in an amount of 0.02 to 5%, more preferably 0.1 to 1%, most preferably 0.1 to 0.3% (percentages are by weight of elemental iron based on the phosphor weight).
Phosphors used for cathode-ray tubes ordinarily have an average particle size in the range of about 5 to about 15,1cm. When a phosphor having an average particle size outside the range of 6 to 10 ym is used, the amount of the applied raw material is adjusted to some extent. More specifically, if the average particle size of the phosphor exceeds 10 ym but does not exceed 1 5 ym, it is preferred that the amount of the raw material be reduced by about 20% from the amount given above. When the average particle size of the phosphor is smaller than 6 4m but larger than 5 ym, it is preferred that the amount of the raw material be increased by about 10% from the amount given above.
Examples of the present invention will now be described, but are not intended to limit the scope of the invention.
Example 1
50 g of a red-luminescent phosphor (Y2O2S:Eu) having an average particle size of 8 ,um was suspended in water, and 1.08 g of ferric nitrate [Fe(NO3)2 . 9H20] was dissolved in the suspension. Then, 29% aqueous ammonia was added dropwise to the solution with agitation to adjust the pH to about 10. In this way, ferric hydroxide was applied to the phosphor. After agitation had been continued for some time, filtration, water washing and drying were carried out to obtain a phosphor which contained pigment raw material in an amount of about 0.2% (by weight of Fe).
Dots of a green-luminescent phosphor and dots of a pigment carrying blue-luminescent phosphor were formed on a face plate of a color cathode-ray tube having a black matrix formed on it by a conventional method. Then, dots of a redluminescent phosphor were formed by using a mixture of the raw material containing redluminescent phosphor of this Example and a known photosensitive composition, using a conventional method. After aluminization frit baking was carried out, resulting in conversion of the raw material containing red-luminescent phosphor into a red pigment carrying redluminescent phosphor.
Example 2
50 g of a red-luminescent pphosphor (Y202S:Eu) was suspended in water and 0.75 g of ferrous sulfate (FeSO4. 7H20) was dissolved in the suspension. Then, 10 ml of 15% aqueous hydrogen peroxide was added dropwise to the solution with agitation. By this operation, ferric oxyhydrate (FeOOH) was attached to the phosphor. After filtration, water washing and drying, calcination was carried out in air at 4000C to obtain an iron oxide carrying phosphor. The amount of the iron oxide adhering to the phosphor was 0.2% by weight (Fe based on the phosphor).
Example 3
50 g of a red-luminescent phosphor (Y202S:Eu) was suspended in water, and 0.75 g of ferrous sulfate was dissolved in the suspension. An aqueous solution containing 0.25 g of sodium hydroxide was added dropwise to this solution.
The liquid mixture was heated at about 500C and an aqueous solution containing 0.05 g of sodium chlorate was added thereto. The mixture was agitated at 500C for 1 hour. By this operation, triiron tetroxide was atached to the phosphor. The phosphor was recovered by filtration, washed with water, dried and calcined in air at 3000C for 2 hours to obtain a pigment carrying phosphor.
The amount of the iron oxide adhering to the phosphor was about 0.2% by weight (Fe based on the phosphor).
Example 4
50 g of a red luminescent phosphor (Y202S:Eu) was suspended in water, and 0.5 g of ferrous sulfate (FeSO4. 7H20) was dissolved in the suspension. An aqueous solution containing 0.25 g of sodium hydroxide was added dropwise to the solution. Sufficient oxygen was blown into the mixture while the mixture was maintained at 500C with agitation, to produce ferric oxyhydrate which thus was attached to the phosphor. Then, the phosphor was recovered by filtration, washed with water, dried and calcined in air at 5000C for 30 minutes to obtain a pigment carrying phosphor. The amount of iron oxide adhering to the phosphor was about 0. 15% by weight (Fe based on the phosphor).
Example 5
50 g of a red luminescent phosphor (Y202S:Eu) was suspended in water, and 1.08 g of ferric nitrate was dissolved in the suspension. An aqueous solution containing 1 .06g of trisodium phosphate dodecahydrate was added dropwise to the solution, causing ferric phosphate to be attached to the phosphor. The phosphor was recovered by filtration, washed with water, dried and calcined in air at 6000C for 30 minutes to obtain a pigment carrying phosphor. The amount of the iron oxide adhering to the phosphor was about 0.2% by weight (Fe based on the phosphor).
Claims (14)
1. A process for preparing a pigment carying red-luminescent phosphor, which comprises incorporating a raw material capable of being converted to a red pigment by calcination in a red-luminescent phosphor and thereafter calcining the raw material containing phosphor to convert the raw material into a red pigment.
2. A process according to claim 1 wherein the said raw material is at least one of ferric hydroxide, ferric oxyhydrate, tri-iron tetroxide, ferrous phosphate, and ferric phosphate.
3. A process according to claim 1 or claim 2 wherein the raw material containing phosphor is calcined in the temperature range 300 to 6000C.
4. A process according to claim 3 wherein the raw material containing phosphor is calcined in the temperature range 380 to 4500C.
5. A process according to any one of the preceding claims wherein the raw material containing phosphor is arranged at the desired positions of red-luminescent phosphor dots or stripes on a face plate of a color cathode ray tube and is then calcined.
6. A process according to any one of the preceding claims wherein the phosphor has an average particle size of 5 to 1 5 Mm,
7. A process according to claim 6 wherein the average particle size of the phosphor is 6 to 10 ,um and the amount of the raw material applied to the phosphor is 0.02 to 5% by weight of Fe based on the phosphor weight.
8. A process according to any one of the preceding claims wherein a divalent or trivalent iron salt or compound is converted in aqueous solution and in the presence of the phosphor into a water-insoluble iron compound, thereby becoming incorporated as the raw material in the phosphor.
9. A process according to claim 8 wherein said iron salt is a ferric salt, said water-insoluble iron compound is ferric hydroxide, and conversion of the ferric salt into ferric hydroxide is achieved by rendering an aqueous solution of the ferric salt alkaline.
10. A process according to claim 9 wherein when the aqueous solution of the ferric salt is made alkaline it is brought to a pH in the range from 10 to 11.
11. A process according to claim 8 wherein said iron salt is a ferrous salt, said water-insoluble iron compound is ferric oxyhydrate and conversion of the ferrous salt to ferric oxyhydrate is achieved by oxidizing an aqueous solution of said ferrous salt.
12. A process according to claim 11 wherein said aqueous solution of the ferrous salt is rendered alkaline and is then oxidized by oxygen or aqueous hydrogen peroxide.
1 3. A process according to claim 8 wherein said iron salt is a ferrous salt, said water insoluble iron compound is tri-iron tetroxide and conversion of the ferrous salt to tri-iron tetroxide is achieved by rendering an aqueous solution of said ferrous salt alkaline and oxidizing the aqueous solution by means of a chloric acid compound.
14. A process according to claim 8 wherein said iron salt is a ferrous or ferric salt, said waterinsoluble iron compound is an iron phosphate and conversion of the ferrous or ferric salt to the iron phosphate is achieved by adding a phosphate to an aqueous solution of said ferrous or ferric salt.
1 5. A process for preparing a pigment-carrying red-luminescent phosphor substantially as herein described in any one of the Examples.
1 6. A pigment-carrying red-luminescent phosphor prepared by a process according to any one of the preceding claims.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11791078A JPS5545712A (en) | 1978-09-27 | 1978-09-27 | Manufacture of pigment-adhered red luminescent fluophor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB2032451A true GB2032451A (en) | 1980-05-08 |
Family
ID=14723201
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB7932450A Withdrawn GB2032451A (en) | 1978-09-27 | 1979-09-19 | Process for Preparing a Pigment-carrying Red-luminescent Phosphor |
Country Status (6)
| Country | Link |
|---|---|
| JP (1) | JPS5545712A (en) |
| DE (1) | DE2939258A1 (en) |
| FI (1) | FI792958A7 (en) |
| FR (1) | FR2437431A1 (en) |
| GB (1) | GB2032451A (en) |
| NL (1) | NL7907195A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3012055A1 (en) * | 1980-03-28 | 1981-10-08 | Videocolor GmbH, 7900 Ulm | Pigmenting phosphor particles by wet process with calcination - in air to increase adhesion and impart hydrophilic nature, useful in colour picture tube |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2900209A1 (en) | 1979-01-04 | 1980-07-24 | Riedel De Haen Ag | METHOD FOR PRODUCING A RED LUMINOUS PIGMENT COVERED WITH RED IRON OXIDE |
| GB2093269B (en) * | 1981-02-17 | 1984-08-30 | Mitsubishi Electric Corp | Color cathode ray tube |
| US4698670A (en) * | 1986-07-14 | 1987-10-06 | Westinghouse Electric Corp. | Cable stereo apparatus |
| KR920002648B1 (en) * | 1989-04-03 | 1992-03-31 | 삼성전관 주식회사 | Fluorescent substance |
| DE19733585C1 (en) * | 1997-08-02 | 1998-10-01 | Philips Patentverwaltung | Haematite-coated phosphor production |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2325110A (en) * | 1939-11-23 | 1943-07-27 | Emi Ltd | Electron discharge device, including fluorescent screen |
| US4021588A (en) * | 1976-01-23 | 1977-05-03 | Rca Corporation | Method for preparing filter-coated phosphor particles |
| JPS5334689A (en) * | 1976-09-13 | 1978-03-31 | Dainippon Toryo Co Ltd | Pigment-attached fluorescent substance |
| DE2723495A1 (en) * | 1977-05-25 | 1978-12-07 | Gte Sylvania Inc | Luminophores for colour television screens - where luminophore is coated with pigment so only one principal light frequency is emitted |
| JPS598380B2 (en) * | 1978-07-04 | 1984-02-24 | 大日本塗料株式会社 | Manufacturing method of pigmented phosphor |
-
1978
- 1978-09-27 JP JP11791078A patent/JPS5545712A/en active Pending
-
1979
- 1979-09-19 GB GB7932450A patent/GB2032451A/en not_active Withdrawn
- 1979-09-24 FI FI792958A patent/FI792958A7/en not_active Application Discontinuation
- 1979-09-25 FR FR7923807A patent/FR2437431A1/en not_active Withdrawn
- 1979-09-27 DE DE19792939258 patent/DE2939258A1/en not_active Withdrawn
- 1979-09-27 NL NL7907195A patent/NL7907195A/en not_active Application Discontinuation
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3012055A1 (en) * | 1980-03-28 | 1981-10-08 | Videocolor GmbH, 7900 Ulm | Pigmenting phosphor particles by wet process with calcination - in air to increase adhesion and impart hydrophilic nature, useful in colour picture tube |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2437431A1 (en) | 1980-04-25 |
| NL7907195A (en) | 1980-03-31 |
| JPS5545712A (en) | 1980-03-31 |
| FI792958A7 (en) | 1981-01-01 |
| DE2939258A1 (en) | 1980-04-03 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |