US Patent 7291573 Low melting glass, sealing composition and sealing paste

A low melting glass, which contains substantially no lead and contains 70-90% of Bi2O3, 1-20% of ZnO, 2-12% of B2O3, 0.1-5% of Al2O3, 0.1-5% of CeO2, 0-5% of CuO, 0-0.2% of Fe2O3 and 0.05-5% of CuO+Fe2O3 in mass %, wherein a content of alkali metal oxides in the glass composition is less than 0.1%, and the glass does not crystallize by pre-baking at a sealing temperature or more, can be used for sealing later, and can suppress deterioration of a material such as platinum or platinum-rhodium to provide a stable melting operation for a long period.