Abstract: A sealing glass composition in powdered form comprising a crystallizable base glass in the vitreous state and vanadium zirconium silicate in an amount from about 0.1 to 1 weight percent of the base glass. The sealing glass also may contain aluminum oxide having a particle size of about 90 to 99 percent minus 325 mesh in an amount from about 0.1 to 1.0 weight percent of the base glass and bismuth nitrate in an amount from about 0.02 to 0.08 weight percent of the base glass. The glass composition can be used to seal cathode ray tube face plates and funnels with excellent results when heated to a hold range of about 4300 C to 4500 C. The crystallized sealing glass exhibits improved adhesion to seal edges of the face plates and funnels, increased strength, and improved resistance to organic contamination.

Abstract: A crystallizable sealing glass composition in powered form that is a blend of a Pbo/ZnO/B.sub.2 O.sub.3 /SiO.sub.2 /BaO glass in the vitreous state and a small effective amount of finely divided zinc zirconium silicate as a nucleating agent. The zinc zirconium silicate has an average particle size of about 2 to 8 microns and is used alone, or in combination, with zirconium silicate having an average particle size of about 20 to 30 microns. The glass composition can be used to seal television picture tubes at 440.degree. C. or 460.degree. C. with excellent results, the early stages of crystallization showing large crystals and large glassy area, as well as DTA curve peaks at 15 to 25 minutes at 440.degree. C.

Abstract: A thermally crystallizable glass of predominantly lead-zinc borate composition is disclosed which is composed of a homogeneous admixture of finely comminuted particles of thermally crystallizable glass and essentially fully crystallized glass particles in a ratio of about 1-10, or more preferably 2-7, parts by weight of crystallized glass particles to one million parts by weight of uncrystallized glass particles and which, in its finely comminuted state, possesses an overall particle size distribution such that it is uniformly composed of particles which are essentially entirely of -100 U.S. Series Sieve screen size and such that between about 65-78 weight percent of such particles are of -325 U.S. Series Sieve screen size.