Lead-free crystal composition, glass and glass article based on this composition

Abstract

The present invention relates to a lead-free crystalline glass composition comprising 58 to 64 wt% SiO2, 0 to 0.5 wt% Al2O3, a mixture of alkali and alkaline earth oxides consisting of 13.8 and 18 wt% of an alkali oxide mixture consisting of K2O and Na2O, and 9 and 15 wt% of an alkaline earth oxide mixture consisting of BaO and SrO, the molar percentage ratio of the alkali oxide mixture to the molar percentage of the alkaline earth oxide mixture being between approximately 2 and approximately 3.6 to 10 wt% ZnO, 0 to 1.20 wt% Sb2O3, 0 to 0.5 wt% SO3, 0 to 6.8 wt% TiO2, and 0 to 6 wt% of La2O3 and 0 to 10% by weight of coloring agents. The invention also relates to a glass based on this composition and to an article manufactured with or containing said glass.

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