US4252669A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Luminescent material and method of making the same
Assignee: Sony Corp
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Filing: 1979-09-19
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Granted: 1981-02-24
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Expires: 1999-09-19
Abstract
Abstract A luminescent material is disclosed which has the general formula: Zn1-xCdxS:Cey, Mz wherein M is at least one alkali metal selected from Li, Na, K, Rb, and Cs, x is from about 0 to about 0.3, y and z are densities (g-atom/mol Zn1-xCdxS) of Ce and M relative to Zn1-xCdxS, y is from about 7x10-6 to about 1.5x10-2, and z is from about 7x10-6 to about 1.5x10-2. A method for making a luminescent material having the general formula: (ZnCd)S:Ce,M wherein M is at least one alkali metal selected from Li, Na, K, Rb and Cs is disclosed which comprises the steps of preparing a mixture of (ZnCD)S:Ce compound, and alkali metal compound, heating the mixture under non-oxidizing atmosphere at a temperature between about 900 DEG C. and about 1170 DEG C., and quenching said mixture from said temperature.
Inventors
- 👤 Hiroji Kawai
- 👤 Tomohiko Abe
- 👤 Shigeru Yokono
- 👤 Teruhiko Hoshina
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:24
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7715; C09K11/7716; C09K11/7717
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
191 words
A method for making a luminescent material having the general formula: Zn.sub.1-x Cd.sub.x S:Ce.sub.y, M.sub.z where M is at least one alkali metal selected from Li, Na, K, Rb and Cs, x is from about 0 to about 0.3, y and z are densities (g-atom/mol Zn 1-x Cd x S) of Ce and M relative to Zn 1-x Cd x S, y is from about 7×10 -6 to about 1.5×10 -2 , and z is from about 7×10 -6 to about 1.5×10 -2 which comprises (1) preparing a mixture of Zn 1-x ,Cd x S, Ce compound in an amount equivalent to y g-atom of Ce/mol Zn 1-x Cd x S and a compound of M which is equivalent to z g-atom of M/mol Zn 1-x Cd x S (2) heating the mixture in a non-oxidizing atmosphere to a temperature between about 900° C. and about 1170° C., said mixture being out of contact with oxygen during the heating, and (3) quenching said mixture by rapid cooling from said heating temperature by removing said mixture from the heating atmosphere and either immersing it in water or by cooling it in air.
Claim 2
Independent Claim
191 words
A method for making a luminescent material having the general formula: Zn.sub.1-x Cd.sub.x S:Ce.sub.y, M.sub.z where M is at least one alkali metal selected from Li, Na, K, Rb and Cs, x is from about 0 to about 0.3, y and z are densities (g-atom/mol Zn 1-x Cd x S) of Ce and M relative to Zn 1-x Cd x S, y is from about 7×10 -6 to about 1.5×10 -2 , and z is from about 7×10 -6 to about 1.5×10 -2 which comprises (1) preparing a mixture of Zn 1-x ,Cd x S, Ce compound in an amount equivalent to y g-atom of Ce/mol Zn 1-x Cd x S and a compound of M which is equivalent to z g-atom of M/mol Zn 1-x Cd x S (2) heating the mixture in a non-oxidizing atmosphere to a temperature between about 900° C. and about 1170° C., said mixture being out of contact with oxygen during the heating, and (3) quenching said mixture by rapid cooling from said heating temperature by removing said mixture from the heating atmosphere and either immersing it in water or by cooling it in air.
Claim 3
Dependent Claim
16 words
The method of claim 1 wherein the heating temperature is between 950° C. and 1080° C.
Claim 4
Dependent Claim
18 words
A method according to claim 1 wherein said Ce compound is Ce 2 (SO 4 ) 3 .
Claim 5
Dependent Claim
16 words
A method according to claim 1 wherein said Ce compound is Ce(NO 3 ) 3 .
Claim 6
Dependent Claim
15 words
A luminescent material made according to the method of claim 1 wherein M is lithium.
References Cited (Backward Citations)
US3269956A
Cited
US3459667A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-02-24 | 1984-08-25 | 1985-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-24 | 1988-08-25 | 1989-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-24 | 1992-08-25 | 1993-02-24 | $7700.00 | Window Closed / Lapsed |