Abstract: Glassy coatings that isolate metal surfaces from carbon particles, and a method of applying the coatings. The coatings composed of essentially K2O, SiO2, and Al2O3, and has a CTE of at least 80×10−7/° C. These glassy coatings, which adhere well to metals, employ a potassium-silicate glass composition in three forms: a pure glass, a glass loaded with inert filler having a CTE higher than the glass itself, and a precursor frit that when “reactive-cerammed” produces a predominantly leucite crystalline phase and forms the glassy coating in-situ on the metal surface, creating a protective layer between the exposed metal surface and corrosive chemical-processing environments.

Abstract: A method of controlling the rheology of a sealing glass paste which comprises incorporating a fine inorganic powder in the paste as a mill addition to impart a steep rheology curve to the paste so that the paste resists flow while at rest, but flows readily when shear stress is applied, the amount of inorganic powder incorporated being not over about 10% by weight.

Abstract: Lead-free, SnO-ZnO-P.sub.2 O.sub.5 glasses contain 25-50 mole percent P.sub.2 O.sub.5 and SnO and ZnO in amounts such that the mole ratio of SnO:ZnO is in the range of 1:1 to 5:1. Optionally, the glasses may contain up to 20 mole percent of modifying oxides including up to 5 mole percent SiO.sub.2, up to 20 mole percent B.sub.2 O.sub.3 and up to 5 mole percent Al.sub.2 O.sub.3, as well as one or more crystallization promoters selected from 1-5 mole percent zircon and/or zirconia and 1-15 mole percent R.sub.2 O. The glasses are particularly useful as sealing glass frits in sealing material to join component parts in articles such as cathode ray tubes. The sealing glass material may contain mill additions to reduce the effective coefficient of thermal expansion in a seal.

Abstract: This invention is directed to the formation of transparent, surface-crystallized glass bodies exhibiting very high mechanical strengths, but low frangibility, consisting essentially, in weight percent, of 2.5-5.0% Li.sub.2 O, 5-10% MgO, 3.5-12%, ZnO, 16-28% Al.sub.2 O.sub.3, and 50-70% SiO.sub.2.