US4038204A
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Alkaline-earth metal halophosphate luminescent composition activated by divalent europium and method of preparing same
Assignee: Philips North America LLC
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Filing: 1968-05-03
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Granted: 1977-07-26
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Expires: 1988-05-03
Abstract
Abstract The luminescent composition alkaline-earth metal halophosphate activated by divalent europium. The phosphor composition is very efficiently excited by ultraviolet to generate blue-green or blue radiations. The exact peak emission and half-width of the emission is determined by the particular alkaline-earth metal and halogen utilized.
Inventors
- 👤 Anselm Wachtel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:18
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7728; C09K11/7737; C09K11/7738; C09K11/7739
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
35 words
A luminescent composition consisting essentially of a matrix of halophosphate of alkaline-earth metal, wherein the halogen if of the group consisting of fluorine, chlorine, bromine, and mixtures thereof, and an activating proportion of divalent europium.
Claim 2
Dependent Claim
35 words
A luminescent composition consisting essentially of a matrix of halophosphate of alkaline-earth metal, wherein the halogen if of the group consisting of fluorine, chlorine, bromine, and mixtures thereof, and an activating proportion of divalent europium.
Claim 3
Dependent Claim
19 words
The luminescent composition as specified in claim 1, wherein said alkaline-earth metal is strontium, and said halogen is chlorine.
Claim 4
Dependent Claim
33 words
The composition as specified in claim 1, wherein the gram-atom ratio of europium to total metal in said composition is from 3.5 × 10 - 3 to 3.5 × 10 - 2 .
Claim 5
Dependent Claim
29 words
The composition as specified in claim 1, wherein the gram-atom ratio of europium to europium plus alkaline-earth metal in said composition is about 1.5 × 10 - 2 .
Claim 6
Dependent Claim
36 words
The composition as specified in claim 1, wherein the composition constituents are represented by the formulation M 5 (PO 4 ) 3 X:Eu 2 + , in which M is alkaline-earth metal and X is halogen.
Claim 7
Dependent Claim
39 words
The composition as specified in claim 1, wherein a portion of said alkaline-earth metal is replaced by aluminum in such amount that the gram-atom ratio of aluminum to total metal in said composition is from about 0.01 to 0.03.
Claim 8
Independent Claim
146 words
The method of preparing a luminescent composition having the matrix M 5 (PO 4 ) 3 X and activated by divalent europium, wherein M is the matrix metal and substantially comprises alkaline-earth metal, and X is halogen of the group consisting of fluorine, chlorine, bromine or mixtures thereof, which method comprises: (a) mixing together raw mix constituents providing said matrix metal, phosphate radical, halogen, and europium in the proportions required to form said luminescent composition; (b) adding to said raw mix additional alkaline-earth metal and said halogen as alkaline-earth metal halide in an amount such that said halide supplies at least 10 atom percent of the total alkaline-earth metal in said raw mix; (c) firing the resulting mixtures in a reducing atmosphere at a predetermined temperature for a predetermined time sufficient to form said composition; and (d) dissolving excess alkaline-earth metal halide from the fired composition.
Claim 9
Independent Claim
146 words
The method of preparing a luminescent composition having the matrix M 5 (PO 4 ) 3 X and activated by divalent europium, wherein M is the matrix metal and substantially comprises alkaline-earth metal, and X is halogen of the group consisting of fluorine, chlorine, bromine or mixtures thereof, which method comprises: (a) mixing together raw mix constituents providing said matrix metal, phosphate radical, halogen, and europium in the proportions required to form said luminescent composition; (b) adding to said raw mix additional alkaline-earth metal and said halogen as alkaline-earth metal halide in an amount such that said halide supplies at least 10 atom percent of the total alkaline-earth metal in said raw mix; (c) firing the resulting mixtures in a reducing atmosphere at a predetermined temperature for a predetermined time sufficient to form said composition; and (d) dissolving excess alkaline-earth metal halide from the fired composition.
Claim 10
Dependent Claim
38 words
The method as specified in claim 7, wherein said additional alkaline-earth metal halide is added to the raw mix in an amount as to constitute about 20 atom percent of the total alkaline-earth metal in the raw mix.
Claim 11
Dependent Claim
43 words
The method as specified in claim 7, wherein 1 to 2 atom percent excess of phosphorus is included in the raw mix over the amount of phosphorus which can combine as orthophosphate with the metal present in the raw mix in oxygen-containing compounds.
Claim 12
Dependent Claim
41 words
The method as specified in claim 7, wherein said additional alkaline-earth metal halide is added to the raw mix in an amount such that said halide supplies from 10 to 50 atom percent of the total alkaline-earth metal in said mixture.
Claim 13
Dependent Claim
32 words
The method as specified in claim 7, wherein said europium is included in said raw mix in an amount of about 1/3 excess europium over the amount actually incorporated into said composition.
Claim 14
Dependent Claim
38 words
The method as specified in claim 7, wherein a portion of said matrix metal is aluminum in an amount such that the gram-atom ratio of aluminum to total metal in said composition is from about 0.01 to 0.03.
Claim 15
Dependent Claim
24 words
The method as specified in claim 7, wherein said dissolving of excess alkaline-earth metal is achieved by leaching said fired composition with distilled water.
Claim 16
Dependent Claim
22 words
The method as specified in claim 7, wherein said firing is at from 900° to 1200° C for at least 1 hour.
Claim 17
Dependent Claim
18 words
The method as specified in claim 14, wherein said firing is at 1100° C for about 3 hours.
Claim 18
Dependent Claim
68 words
A photoluminescent composition consisting essentially of halophosphate of alkaline-earth metal represented by the formula M 5 (PO 4 ) 3 X:Eu 2 + , in which M is strontium, calcium, barium, or mixtures thereof, X is fluorine, chlorine, bromine, or mixtures thereof, and the gram-atom ratio of europium to total metal in said composition is from 3.5 × 10 - 3 to 3.5 × 10 - 2 .
Claim 19
Dependent Claim
68 words
A photoluminescent composition consisting essentially of halophosphate of alkaline-earth metal represented by the formula M 5 (PO 4 ) 3 X:Eu 2 + , in which M is strontium, calcium, barium, or mixtures thereof, X is fluorine, chlorine, bromine, or mixtures thereof, and the gram-atom ratio of europium to total metal in said composition is from 3.5 × 10 - 3 to 3.5 × 10 - 2 .
Claim 20
Dependent Claim
38 words
The photoluminescent composition as specified in claim 16, wherein aluminum replaces a portion of said alkaline-earth metal in such amount that the gram-atom ratio of aluminum to total metal in said composition is from about 0.01 to 0.03.
Claim 21
Dependent Claim
34 words
A luminescent composition consisting essentially of a matrix of halophosphate of alkaline-earth metal, wherein the alkaline-earth is calcium, barium, and/or strontium, the halogen is chlorine and/or bromine, and an activating proportion of divalent europium.
Claim 22
Dependent Claim
34 words
A luminescent composition consisting essentially of a matrix of halophosphate of alkaline-earth metal, wherein the alkaline-earth is calcium, barium, and/or strontium, the halogen is chlorine and/or bromine, and an activating proportion of divalent europium.
References Cited (Backward Citations)
US2986529A
Cited
US3328620A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-07-25 | 1981-01-24 | 1981-07-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-25 | 1985-01-24 | 1985-07-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-25 | 1989-01-24 | 1989-07-26 | $7700.00 | Window Closed / Lapsed |