Beta-quartz glass-ceramics with high zinc content

Abstract

The present application provides LAS type transparent glass-ceramics of β-quartz of composition containing a high content of zinc, articles constituted at least in part of said glass-ceramics, glasses precursors of said glass-ceramics (with a low viscosity at high temperature), and also a method of preparing said articles. Said glass-ceramics present a composition, free of arsenic oxide and antimony oxide, except for inevitable traces, expressed as percentages by weight of oxides, containing: 64.5% to 66.5% of SiO2; 19.0% to 20.6% of Al2O3; 3.0% to 3.6% of Li2O; 0 to 1% of MgO; 1.7% to 3.4% of ZnO; 2% to 3% of BaO; 0 to 3% of SrO; 0 to 1% of CaO; 2% to 4% of TiO2; 1% to 2% of ZrO2; 0 to 1% of Na2O; 0 to 1% of K2O; with Na2O+K2O+BaO+SrO+CaO≤6%; optionally up to 2% of at least one fining agent comprising SnO2; and optionally up to 2% of at least one coloring agent.

Dependencies are inferred from the claim text.