GLASSES AND GLASS-CERAMICS CONTAINING SIO2, TA2O5 AND NA2O

摘要

1389688 Crystallizable glass OWENSILLINOIS Inc 7 Aug 1972 [5 Aug 1971] 36773/72 Heading C1M A thermally crystallizable glass comprises, in mole per cent: the balance, if any, consisting of other compatible ingredients. The molar ratio of Na 2 O to Ta 2 O 5 is preferably 0À7 : 1 to 1À2 : 1. The glass, which may have a refractive index of at least 1À78 (e.g. 1À80-1À95), may be in situ crystallized to form a transparent glass-ceramic containing NaTaO 3 as the predominant crystal phase. The transparent glass-ceramic may have a refractive index of 1À83-2À00. An opaque glass-ceramic may be formed by further heat treatment.