Process for coating envelope for reflector-type fluorescent lamp and the lamp resulting therefrom

Claim 1

The method of coating the elongated envelope of a reflector-type fluorescent lamp while using only one lehring operation to remove binder in one step from the coated reflective material and coated phosphor material, the reflector comprising finely divided white-appearing material coated onto and extending radially around only a predetermined proportion of the interior circumferential surface of said envelope to leave a reflective-material-uncoated longitudinal aperture through which the generated light may pass, and light-generating finely divided phosphor coated over both the reflective material coating and the remaining longitudinal aperture, which method comprises: (a) flowing over only a predetermined proportion of the interior circumferential surface of an elongated fluorescent tube, a reflective material coating paint slurry comprising a mixture of finely divided titania and phosphor in the relative weight proportions of about 25 to 50% titania and about 75 to 50% phosphor both suspended in organic solvent having dissolved therein binder material which is insoluble in water to provide the slurry with a predetermined viscosity to deposit a predetermined weight of reflective material slurry onto said envelope; (b) evaporating organic vehicle from the applied reflective material coating; (c) flowing over the entire envelope interior surface a phosphor coating paint slurry comprising finely divided phosphor material suspended in aqueous vehicle having dissolved therein water soluble binder material to provide the phosphor slurry with a predetermined viscosity to deposit a predetermined weight of phosphor material slurry onto said envelope; (d) lehring in one step the coated envelope at a sufficient temperature and for a sufficient time to burn out and remove residual binders from the applied material coatings; and (e) end cleaning said envelope to remove reflective material and phosphor material from the envelope end portions for a sufficient distance to permit cathode carrying amounts to be sealed in the cleaned ends thereof.

Claim 2

The method of coating the elongated envelope of a reflector-type fluorescent lamp while using only one lehring operation to remove binder in one step from the coated reflective material and coated phosphor material, the reflector comprising finely divided white-appearing material coated onto and extending radially around only a predetermined proportion of the interior circumferential surface of said envelope to leave a reflective-material-uncoated longitudinal aperture through which the generated light may pass, and light-generating finely divided phosphor coated over both the reflective material coating and the remaining longitudinal aperture, which method comprises: (a) flowing over only a predetermined proportion of the interior circumferential surface of an elongated fluorescent tube, a reflective material coating paint slurry comprising a mixture of finely divided titania and phosphor in the relative weight proportions of about 25 to 50% titania and about 75 to 50% phosphor both suspended in organic solvent having dissolved therein binder material which is insoluble in water to provide the slurry with a predetermined viscosity to deposit a predetermined weight of reflective material slurry onto said envelope; (b) evaporating organic vehicle from the applied reflective material coating; (c) flowing over the entire envelope interior surface a phosphor coating paint slurry comprising finely divided phosphor material suspended in aqueous vehicle having dissolved therein water soluble binder material to provide the phosphor slurry with a predetermined viscosity to deposit a predetermined weight of phosphor material slurry onto said envelope; (d) lehring in one step the coated envelope at a sufficient temperature and for a sufficient time to burn out and remove residual binders from the applied material coatings; and (e) end cleaning said envelope to remove reflective material and phosphor material from the envelope end portions for a sufficient distance to permit cathode carrying amounts to be sealed in the cleaned ends thereof.