Incandescent lamp with fluorine cycle - has inner protective coating of fluoro complex dissociating into gaseous Lewis acid and firmly adhering Lewis base

摘要

Incandescent lamp with a F cyclic process has a quartz or hard glass envelope, a filling gas contg. F, an incandescent body of metal (W), nonmetal (C) or a cpd. (Ta carbide) and a protective coating on the inside walls of the envelope and the supporting pts. Protection against attack by F2 is provided by fluoro complexes (I) which dissociate into a gaseous Lewis acid and a firmly adhering Lewis base, depending on the operating temp. and pressure and filling gas, according to the equation M(AFn+x) left arrow right arrow MFx.AFn left arrow right arrow MFx+AFn (in which M is an aliali(ne earth) metal (Li, Na, Rb, Cs, Mg, Ca, Sr, Ba) or Zn. a is B, Si, P, Sbor As. x = 1 or 2. n = 3,4 or 5). (I) is a fluoroborate or hexafluoro-silicate, -phosphate, -arsenate or -antimonate of the type MBF4, M(BF4)2, -arsenate or -antimonate of the type MBF4, M(BF4)2, M2SiF6, MSiF6, MPF6, M(PF6)2, MAsF6, M(AsF6)2, MSbF6 or M(SbF&)2. The light output and lifetime are much higher than usual.