Alkaline earth alumino-borosilicate crack resistant glass

Abstract

The present disclosure relates to glass articles for use as a touchscreen substrate or cover glass article for use in a portable electronic device, particularly an aluminoborosilicate glass being substantially free of alkalis, comprising at least 55 mol % SiO2, at least 5 mol % Al2O3 and at least one alkaline earth RO component. The alkali-free aluminoborosilicate exhibits an Al2O3+B2O3 to RO mol % ratio which exceeds 1 and an Al2O3 to RO mol % ratio which exceeds 0.65. The aluminoborosilicate glasses disclosed herein exhibits high damage resistance as evidenced by a Vickers median/radial crack initiation load which is greater than than 1000 gf, as well as a high scratch resistance of at least 900 gf, as measured by the lack of the presence of lateral cracks when a load is applied by a moving Knoop indenter.

Dependencies are inferred from the claim text.