Sealing glass vehicle and composition and method for making same

Abstract

Abstract A sealing glass and a sealing glass paste for sealing the face plate and funnel portion of a color television tube wherein PbO-containing sealing glass frit contains from an effective amount of a powder, such as Pb 3 O 4 powder, which powder prevents the reduction of PbO to Pb metal during the sealing process, which reduction would otherwise result in a dielectric breakdown in the seal. A sealing glass paste consisting essentially of a PbO-B 2 O 3 -ZnO sealing glass frit and containing an effective amount of said powder, based upon the weight of the frit, together with hydroxypropyl cellulose binder for the frit and a solvent for the binder. A method for sealing the face plate of a color television tube to its funnel portion with a PbO-containing solder glass wherein the reduction of PbO to metallic lead during the sealing step is obviated by the addition of a sufficient amount of Pb 3 O 4 or BaO 2 powder in the solder glass and paste made therewith, which Pb 3 O 4 or BaO 2 is slowly reduced to a lower oxide in a reducing atmosphere during the sealing of the television tube components. A method for increasing the dielectric properties of a PbO-containing sealing glass paste and the devitrified seal made therefrom, which seals the face plate to the funnel of a color television tube, to a value greater than that provided by the solder glass, per se, by incorporating in the solder glass and the solder glass paste made therefrom a small but sufficient amount of Pb 3 O 4 or BaO 2 to accomplish this purpose. A vehicle for the glass frit comprises hydroxypropyl cellulose as a binder and a solvent for said binder.

Inventors

• 👤 Josef Francel
• 👤 James E. King
• 👤 John M. Woulbroun

Bibliographic Details