SILICON DIOXIDE SELECTIVELY REFLECTING LAYER FOR MERCURY VAPOR DISCHARGE LAMPS

摘要

An improved mercury vapor discharge lamp is disclosed. The lamp of the present invention includes an envelope and a selectively reflecting silicon dioxide layer on at least a portion of the inner surface of the envelope. The lamp further includes a phosphor coating disposed on the selectively reflecting layer. The silicon dioxide layer has a coating weight of from about 0.1 to about 4 mg/cm2. The selectively reflecting layer comprises at least about 80 weight percent silica having a primary particle size from about 5 to about 100 nm with at least about 50 weight percent of the silica having a primary particle size from about 17 to about 80 nm.