Inventors:
Chung Nin Chau - Sayne PA
Tracy V. Silloway - Hampton NH
Paul W. Salvi - Danville NH
Assignee:
Osram Sylvania Inc. - Danvers MA
International Classification:
B32B 516
B05D 722
B05D 506
Abstract:
A method for providing an adherent, continuous, conformal, non-particulate coating of a compound of a metal or metalloid on the surface of individual phosphor particles. The method involves wetting each of the individual particles with a polymer solution including a polymer in a solvent base, the polymer being capable of chelating ions of the metal or metalloid. The particles then are dried to produce a continuous coating of the polymer on each of the individual particles. The polymer-coated phosphor particles are suspended in a solution containing ions of the metal or metalloid and having a pH of at least 9 to produce chelation of the metal or metalloid ions by the polymer coating, to produce the adherent, continuous, conformal, non-particulate, metal- or metalloid-compound coating on the particle surfaces. Also described are a method for improving lumen maintenance of a lamp, a coated phosphor powder, and a phosphor-coating composition for coating an inner surface of a lamp envelope.