FINING AGENTS FOR SILICATE GLASSES

摘要

A fining agent for reducing the concentration of seeds or bubbles in a silicate glass. The fining agent includes at least one inorganic compound, such as a hydrate or a hydroxide that acts as a source of water. In one embodiment, the fining agent further includes at least one multivalent metal oxide and, optionally, an oxidizer. A fusion formable and ion exchangeable silicate glass having a seed concentration of less than about 1 seed/cm3 is also provided. Methods of reducing the seed concentration of a silicate glass, and a method of making a silicate glass having a seed concentration of less than about 1 seed/cm3 are also described.

主权项

1. A method of making a silicate glass having a seed concentration of less than about 1 seed/cm3, wherein the method comprises:
melting at a first temperature a glass batch comprising 60-70 mol % SiO2; 6-14 mol % Al2O3; 0-3 mol % B2O3; 0-1 mol % Li2O; 8-18 mol % Na2O; 0-5 mol % K2O; 0-2.5 mol % CaO; above 0 to 3 mol % ZrO2; 0-1 mol % SnO2; and 0-1 mol % CeO2; wherein 12 mol %≦Li2O+Na2O+K2O≦20 mol %, and wherein the glass batch comprises less than 50 ppm As2O3; and heating at a second temperature greater than the first temperature for a time sufficient to produce the silicate glass having a seed concentration of less than about 1 seed/cm3.