US4122349A
Expired / Lapsed
US
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Novel luminophores emitting ultraviolet radiation, and uses thereof
Assignee: Rhone Poulenc Industries SA
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Filing: 1977-01-26
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Granted: 1978-10-24
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Expires: 1997-01-26
Abstract
Abstract Novel alkaline earth metal fluosilicates which are activated with divalent europium are disclosed corresponding to the formula: M.sub.1-x Eu.sub.x.sup.2+ Si F.sub.6 wherein O < x ≦ 0.2 and M represents at least one alkaline earth metal from the group of barium and srontium. These fluosilicates exhibit luminescent activities emitting sharp line radiation in the near ultraviolet region and are especially suited for producing black light, e.g., within discharge lamps.
Inventors
- 👤 Claude Fouassier
- 👤 Bertrand Latourette
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:06
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/08; C01B33/10; C01B33/103; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7728; C09K11/7732; C09K11/7733; C09K11/77342; H; H01; H01J; H01J35/00; H01J35/02
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
57 words
A luminescent fluosilicate of the formula M.sub.1-x Eu.sub.x.sup.2+ Si F.sub.6 wherein O < x ≦ .2 and M represents at least one alkaline earth metal selected from the group consisting of barium and strontium, said fluosilicate emitting an intense line emission at about 3600A when excited by ultraviolet radiation of a wavelength between about 2300A and 3200A.
Claim 2
Dependent Claim
57 words
A luminescent fluosilicate of the formula M.sub.1-x Eu.sub.x.sup.2+ Si F.sub.6 wherein O < x ≦ .2 and M represents at least one alkaline earth metal selected from the group consisting of barium and strontium, said fluosilicate emitting an intense line emission at about 3600A when excited by ultraviolet radiation of a wavelength between about 2300A and 3200A.
Claim 3
Dependent Claim
15 words
The fluosilicate as defined in claim 1, wherein x is 0.0225 and M is strontium.
Claim 4
Dependent Claim
15 words
The fluosilicate as defined in claim 1, wherein x is 0.0175 and M is barium.
Claim 5
Dependent Claim
16 words
The fluosilicate as defined in claim 1, wherein M represents a mixture of barium and strontium.
Claim 6
Dependent Claim
16 words
The fluosilicate as defined in claim 4, corresponding to the formula Sr.sub.0.489 Ba.sub.0.489 Eu.sub.0.022 Si F.sub.6
Claim 7
Dependent Claim
49 words
a method for producing black light which comprises the step of irradiating a luminescent material comprising a luminescent fluosilicate as defined in claim 1 with an ultraviolet radiation of a wavelength of between 2300A and 3200A to effect an intense line emission from said luminescent material at about 3600A.
References Cited (Backward Citations)
US3630945A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-10-23 | 1982-04-24 | 1982-10-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-10-23 | 1986-04-24 | 1986-10-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-10-23 | 1990-04-24 | 1990-10-24 | $7700.00 | Window Closed / Lapsed |