Patent ID: 6936555
Filing Date: 2005-08-30
Classification: C03C

Abstract:
1. A substantially transparent glass-ceramic whose composition lies within the SiO 2 —Al 2 O 3 —ZnO—K 2 O—Ga 2 O 3 —Na 2 O system and containing a hexagonal ZnO crystal phase, the composition consisting essentially, in weight percent on an oxide basis, of 25-50% SiO 2, 15-45% ZnO, 0-26% Al 2 O 3 , 0-25% K 2 O, 0-10% Na 2 O, 0-32% Ga 2 O 3 , a K 2 O+Na 2 O amount of greater than 10%, a Al 2 O 3 +Ga 2 O 3 of greater than 10%, the glass ceramic microstructure containing a total hexagonal ZnO crystallinity of at least 15%.