US5116532A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making lanthanum cerium terbium phosphate phosphor
Assignee: Osram Sylvania Inc
•
Filing: 1990-05-14
•
Granted: 1992-05-26
•
Expires: 2010-05-14
Abstract
Abstract A method of making a lanthanum cerium terbium phosphate phosphor involves the single-step reaction of a single-phase, mixed valence state lanthanum cerium terbium oxide and boron phosphate. Alternatively, the single-step reaction may involve a mixture of lanthanum oxide, cerium oxide, terbium oxide and boron phosphate.
Inventors
- 👤 Chung N. Chau
- 👤 Anthony F. Kasenga
- 👤 Charles F. Chenot
- 👤 Leslie F. Gray
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 08:14
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7766; C09K11/7777
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
63 words
A method of making lanthanum cerium terbium phosphate phosphor, comprising the steps of: a) reacting single-phase lanthanum cerium terbium oxide with boron phosphate at about 1150° C. to about 1300° C. in an inert or reducing atmosphere to form a mixture comprising lanthanum cerium terbium phosphate phosphor and boron oxide; and b) separating said lanthanum cerium terbium phosphate phosphor from said boron oxide.
Claim 2
Independent Claim
63 words
A method of making lanthanum cerium terbium phosphate phosphor, comprising the steps of: a) reacting single-phase lanthanum cerium terbium oxide with boron phosphate at about 1150° C. to about 1300° C. in an inert or reducing atmosphere to form a mixture comprising lanthanum cerium terbium phosphate phosphor and boron oxide; and b) separating said lanthanum cerium terbium phosphate phosphor from said boron oxide.
Claim 3
Dependent Claim
21 words
The method of claim 1 wherein said lanthanum cerium terbium oxide and said boron phosphate are provided in near stoichiometric proportions.
Claim 4
Dependent Claim
28 words
The method of claim 2 wherein said lanthanum cerium terbium oxide and said boron phosphate are provided in a molar ratio of from about 1:1 to about 1:1.05.
Claim 5
Dependent Claim
17 words
The method of claim 1 wherein said reaction step occurs for about 1.5 to about 4 hours.
Claim 6
Dependent Claim
18 words
The method of claim 4 wherein said reaction step occurs at about 1200° C. for about 4 hours.
Claim 7
Dependent Claim
14 words
The method of claim 4 wherein said reaction step occurs in an inert atmosphere.
Claim 8
Dependent Claim
14 words
The method of claim 4 wherein said reaction step occurs in a reducing atmosphere.
Claim 9
Dependent Claim
13 words
The method of claim 1 wherein said separation step is performed by washing.
Claim 10
Dependent Claim
15 words
The method of claim 8 wherein said washing is performed in acidic and basic solutions.
Claim 11
Dependent Claim
13 words
The method of claim 9 wherein said acidic solution is dilute nitric acid.
Claim 12
Dependent Claim
13 words
The method of claim 9 wherein said basic solution is dilute ammonium hydroxide.
Claim 13
Independent Claim
65 words
A method of making lanthanum cerium terbium phosphate phosphor, comprising the steps of: a) reacting lanthanum oxide, cerium oxide, and terbium oxide with boron phosphate at about 1150° C. to about 1300° C. in an inert or reducing atmosphere to form a mixture comprising lanthanum cerium terbium phosphate phosphor and boron oxide; and b) separating said lanthanum cerium terbium phosphate phosphor from said boron oxide.
Claim 14
Independent Claim
65 words
A method of making lanthanum cerium terbium phosphate phosphor, comprising the steps of: a) reacting lanthanum oxide, cerium oxide, and terbium oxide with boron phosphate at about 1150° C. to about 1300° C. in an inert or reducing atmosphere to form a mixture comprising lanthanum cerium terbium phosphate phosphor and boron oxide; and b) separating said lanthanum cerium terbium phosphate phosphor from said boron oxide.
Claim 15
Dependent Claim
25 words
The method of claim 12 wherein said lanthanum oxide, said cerium oxide, said terbium oxide and said boron phosphate are provided in near stoichiometric proportions.
Claim 16
Dependent Claim
17 words
The method of claim 12 wherein said reaction step occurs for about 1.5 to about 4 hours.
Claim 17
Dependent Claim
18 words
The method of claim 14 wherein said reaction step occurs at about 1200° C. for about 4 hours.
Claim 18
Dependent Claim
14 words
The method of claim 14 wherein said reaction step occurs in an inert atmosphere.
Claim 19
Dependent Claim
14 words
The method of claim 14 wherein said reaction step occurs in a reducing atmosphere.
Claim 20
Dependent Claim
13 words
The method of claim 12 wherein said separation step is performed by washing.
Claim 21
Dependent Claim
15 words
The method of claim 18 wherein said washing is performed in acidic and basic solutions.
Claim 22
Dependent Claim
13 words
The method of claim 19 wherein said acidic solution is dilute nitric acid.
Claim 23
Dependent Claim
13 words
The method of claim 19 wherein said basic solution is dilute ammonium hydroxide.
References Cited (Backward Citations)
US3544483A
Cited
DE2534834A1
Cited
US4127415A
Cited
JPS5456086A
Cited
US4423349A
Cited
JPS57133182A
Cited
GB2124243A
Cited
JPS59179578A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-05-26 | 1995-11-25 | 1996-05-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-05-26 | 1999-11-25 | 2000-05-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-05-26 | 2003-11-25 | 2004-05-26 | $7700.00 | Window Closed / Lapsed |