Compositions – Inorganic luminescent compositions – Compositions containing halogen; e.g. – halides and oxyhalides
Patent
1991-02-25
1991-11-26
Cooper, Jack
Compositions
Inorganic luminescent compositions
Compositions containing halogen; e.g., halides and oxyhalides
C09K 1163
Patent
active
050680552
ABSTRACT:
A europium activated strontium tetraborate UV emitting phosphor is disclosed having a weight composition of from about 34.72% to about 35.80 strontium %, from about 17.66% to about 17.78 boron %, from about 0.37% to about 1.86% europium, and the balance oxygen. The phosphor has essentially elongated prism-like particles with the europium relatively uniformly distributed throughout the balance of the phosphor and with the particle size distribution being characterized by the 50% size being in the range of from about 7 micrometers to about 12 micrometers as determined by Coulter Counter measurement and with less than about 12% by weight of the particles having a particle size of greater than about 16 micrometers as determined by Coulter Counter measurement. The process for making the phosphor is disclosed which involves forming a mixture of strontium carbonate and europium carbonate in an aqueous solution of boric acid at a temperature of at least about 70.degree. C. with the mole ratio of SrCO.sub.3 to H.sub.3 BO.sub.3 being from about 1:4 to 1:4.5 and the Eu.sub.2 O.sub.3 content being from about 0.003 to 0.015 moles. The mixture is digested at at least about 90.degree. C. for a sufficient time to form a solid precipitate comprising a strontium borate hydrate intermediate and a liquor, followed by separating the solid from the liquor, drying the solid and firing the solid in an atmosphere of 0.3%, to 3.0% by volume hydroen and the balance nitrogen at at least about 800.degree. C. for a sufficient time to produce the phosphor.
REFERENCES:
patent: 4719033 (1988-01-01), Chenot et al.
Machida et al., "J. of Lumin.", 21, (1979) pp. 101-110.
Torii et al., "Chem. Abstracts", vol. 82, 1975, 37922w.
Chenot Charles F.
Krebs Michael A.
Cooper Jack
GTE Products Corporation
Levy Elizabeth A.
LandOfFree
Europium activated strontium tetraborate UV phosphors does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Europium activated strontium tetraborate UV phosphors, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Europium activated strontium tetraborate UV phosphors will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2385226