process for the production of a glass with a well-defined transformationstemperatur

摘要

A process for the in situ fabrication of a glass from an admixed frit, for example, of two starting glasses on the required existing substrate structure therefore. The admixed frit comprises a low glass transition temperature glass and a higher glass transition temperature glass, which glasses are uniquely capable of forming a continuous vitreous phase over their entire compositional range. During thermal cycling, the low glass transition temperature glass flows out and solubilizes the higher glass transition temperature glass to thereby synthesize in situ a new glass. The temperature required to form the glass by the in situ process is less than that required where a glass of identical composition is first preequilibrated externally and then applied in frit form to the existing substrate structure and flowed out thereon. The in situ synthesized new glass softens and flows at a temperature higher than that of the low glass transistion temperature glass and lower than that of the higher glass transition temperature glass, and exhibits a glass transition temperature intermediate to the two starting glasses.