Fusion seal and sealing mixtures
AssigneeCorning Incorporated
InventorRobert Morena
Life of this patent
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Abstract
A fusion seal between two surfaces, and a material to produce the seal, consist essentially of 60-90 percent by weight of a SnO--ZnO--P.sub.2 O.sub.5 glass frit and 10-40 percent by weight of a mill addition including alumina and, optionally, zircon, the alumina content being at least 10% when it constitutes the mill addition and not over 20% in conjunction with zircon, 0-15 % of a further additive that reduces the effective CTE of the seal, the mill addition being present in a sufficient amount to cause a substantial change in viscosity-temperature characteristics of the material after formation of a seal. The effect of the mill addition on viscosity in a fusion seal finds particular application in uniting the faceplate and funnel members to form a cathode ray tube envelope.
Claims19
A fusion seal between the surfaces of two bodies, the fusion seal consisting essentially of 60-90% by weight of a SnO--ZnO--P.sub.2 O.sub.5 glass frit wherein the SnO and ZnO are present in the glass in a molar ratio of 5:1 to 2:1, and 10-40 percent by weight of a mill addition comprising alumina and, optionally, zircon, the alumina content being at least 10% when it constitutes the mill addition and not over 20% in conjunction with zircon, the total amount of alumina and zircon being 10-40%, the seal having a phosphate crystal phase crystallized in situ which, in combination with the mill addition, causes a substantial change in the viscosity temperature characteristics of the seal.
A fusion sealing material consisting essentially of 60-90% by weight of a SnO--ZnO--P.sub.2 O.sub.5 glass frit wherein the SnO and ZnO are present in the glass in a molar ratio of 5:1 to 2:1, and 10-40 percent by weight of a mill addition comprising alumina and, optionally, zircon, the alumina content being at least 10% when it constitutes the mill addition and not over 20% in conjunction with zircon, the total amount of alumina and zircon being 10-40%, the sealing material being capable of thermal treatment to develop a phosphate crystal phase that substantially changes the effective the viscosity temperature characteristics of a seal formed from the material whereby the seal does not soften upon reheating.
Dependencies are inferred from the claim text.