Patents by Inventor Francois Pingault

Francois Pingault has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Method of producing a luminescent alkaline earth metal fluorohalide activated by bivalent europium
    Patent number: 4157981
    Abstract: Method of preparing a luminescent alkaline earth metal fluorohalide activated by Eu.sup.2+ defined by the formula Me.sub.1-p Eu.sub.p FX (Me=Ba, Sr; X=Cl, Br, I; 0.001.ltoreq.p.ltoreq.0.20). MeF.sub.2 is suspended in water after which 1 mole of MeX.sub.2 per mole of MeF.sub.2 is dissolved in the suspension. The suspension, which may already contain europium, is evaporated to dryness at 50.degree. C. to 250.degree. C. The obtained product is mixed with the additional required amount of europium in the form of a europium halide and then is subjected to at least one temperature treatment at 600.degree. C. to 1000.degree. C. in a weakly reducing atmosphere. The obtained reaction product is subjected, possibly after being ground, to a final heating at 600.degree. C. to 850.degree. C. in an inert or weakly reducing atmosphere.
    Type: Grant
    Filed: April 3, 1978
    Date of Patent: June 12, 1979
    Assignee: U.S. Philips Corporation
    Inventors: Albert L. N. Stevels, Agnes D. M. Schrama-de Pauw, Francois Pingault