US5413736A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Particulate fluorescent material of (Y1-X" Eux)203 and process of preparing same
Assignee: National Institute of Advanced Industrial Science and Technology
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Filing: 1994-02-15
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Granted: 1995-05-09
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Expires: 2014-02-15
Abstract
Abstract A fluorescent material is disclosed which indludes substantially spherical particles each consisting of Y2O3 and Eu2O3 and having an average particle diameter of 90-210 nm and a narrow particle size distribution. The fluorescent material may be produced by heating an aqueous solution having a pH of 3 or less and containing a yttrium salt, a europium salt and urea at a temperature of at least 90 DEG C. to coprecipitate YOHCO3 and EuOHCO3 as particles having an average particle diameter of 110-270 nm. The resulting particles are then calcined at a temperature of at least 600 DEG C. to form spheres each consisting of Y2O3 and Eu2O3.
Inventors
- 👤 Yoshihiro Nishisu
- 👤 Mikio Kobayashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:35
CPC Classifications
B; B82; B82Y; B82Y30/00; C; C01; C01F; C01F17/00; C01F17/20; C01F17/206; C01F17/241; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7783; C09K11/7784; C09K11/7787; C01P; C01P2004/00; C01P2004/30; C01P2004/32; C01P2004/51; C01P2004/52; C01P2004/60; C01P2004/62; C01P2004/64
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
128 words
A process for the production of a fluorescent material comprising the steps of: providing an aqueous solution having a pH of 3 or less and containing a yttrium salt, a europium salt and urea; heating said solution at a temperature of at least 90° C. to precipitate particles, each of said particles consisting of a mixture of YOHCO 3 and EuOHCO 3 , said particles having an average particle diameter of 110-270 nm and such a particle size distribution that more than 99% by weight of said particles have particle diameters of D±50 nm; and calcining said particles at a temperature of at least 600° C. to form spheres, each sphere having the composition (Y 1-x , Eu x ) 2 O 3 wherein x is 0 001-0.2.
Claim 2
Dependent Claim
128 words
A process for the production of a fluorescent material comprising the steps of: providing an aqueous solution having a pH of 3 or less and containing a yttrium salt, a europium salt and urea; heating said solution at a temperature of at least 90° C. to precipitate particles, each of said particles consisting of a mixture of YOHCO 3 and EuOHCO 3 , said particles having an average particle diameter of 110-270 nm and such a particle size distribution that more than 99% by weight of said particles have particle diameters of D±50 nm; and calcining said particles at a temperature of at least 600° C. to form spheres, each sphere having the composition (Y 1-x , Eu x ) 2 O 3 wherein x is 0 001-0.2.
Claim 3
Dependent Claim
15 words
The process of claim 1 wherein said heating is at a temperature of 95°-98° C.
Claim 4
Dependent Claim
22 words
The process of claim 2 wherein said heating is continued until the pH of the reaction mixture increases to at least 7.
Claim 5
Dependent Claim
22 words
The process of claim 1 wherein said heating is continued until the pH of the reaction mixture increases to at least 7.
References Cited (Backward Citations)
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