Light-screening film paint for lamps, and light-screening film for lamps and producing method thereof

摘要

When in use a highly luminous automobile discharge lamp will experience a temperature rise to about 700° C. at the lamp glass surface. As such, the light-screening film formed on the lamp will also be exposed to a temperature of 700° C.; the temperature of the glass surface of a lamp rises and, accordingly, that of the light- screening film formed thereon also rises. Especially with a highly luminous automobile discharge lamp, the temperature of the lamp glass surface rises to about 700° C. during the lighting. Necessarily, the light- screening film on the glass surface is also exposed to a temperature of 700° C. As such, a light-screening film material free of discoloration or peeling even after exposure to a temperature of 700° C. has been desired. There is disclosed a light-screening film paint for lamps containing (1) at least one compound of either manganese oxide or an iron oxide compound doped with a metallic manganese and having the formula (Fe.sub.x Mn.sub.1-x).sub.2 O.sub.3 where 0.95 x 0.70; and (2) powder glass containing at least one of silica, zinc oxide, boron oxide and aluminum oxide. A light-screening film is produced by applying the paint to the surface of a lamp, followed by the firing at a temperature of not higher than 1,200° C.