Chemically strengthened glass and methods of making same

Abstract

In one aspect, a method for use in preparing a glass comprises: performing a first ion exchange process to replace at least a first ion in the glass with at least a second ion, the second ion being smaller than the first ion; and performing a second ion exchange process to replace at least the second ion in the glass with at least a third ion, the third ion being larger than the first ion. In another aspect, a glass is prepared at least in part by: performing a first ion exchange process to replace at least a first ion in the glass with at least a second ion, the second ion being smaller than the first ion; and performing a second ion exchange process to replace at least the second ion in the glass with at least a third ion, the third ion being larger than the first ion.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S)[0001]The present application is a continuation of U.S. patent application Ser. No. 15 / 002,359, filed Jan. 20, 2016, having the same title and inventors as the present application, the disclosure of which is hereby incorporated by reference herein in its entirety for all purposes.BACKGROUND OF THE INVENTION[0002]The present invention relates generally to the chemical arts, and, more particularly, to chemically strengthened glass and a method for its manufacture.[0003]Chemically strengthened glasses have been used widely in mobile devices. Typically, a glass, such as aluminosilicate glass, is treated at high temperature in molten potassium (K) salt, such as potassium nitrate (KNO3). The sodium (Na) ions in the surface layer of the glass are replaced by potassium ions.[0004]Because potassium ions are of larger size than sodium ions, a compressive stress is created in the surface of the glass. The central portion of the glass is under tensile st...

AI Technical Summary

Benefits of technology

The patent describes a method for making glass by replacing ions in the glass with smaller ions and then replacing those ions with larger ions. This process can create glass with specific properties, such as being strong or having good optical properties. The technical effect of this method is the ability to create glass with specific properties by replacing ions with other ions.

Problems solved by technology

However, if the tensile stress in the glass is above a threshold value, a small fracture in the tensile region will trigger the fracturing in the tensile region.

If the surrounding compressive layer is thin, the fracture in the tensile region will penetrate the compressive layer and shatter the whole glass.

However, while a thicker compressive layer will advantageously increase the resistance of glass to scratches or surface damages, it will also undesirably increase the thickness and weight of glass.

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