Patent ID: 7309671

Claim:
A chemically strengthened glass article obtained by immersing a glass article comprising a glass composition in a molten salt containing monovalent cations having an ionic radius larger than that of Na ions to conduct an ion-exchange treatment between the Na ions and the monovalent cations, wherein the glass composition essentially comprises: 60 to 70 wt % SiO 2 ; 8 to 15 wt % Al 2 O 3 ; 0 to 1 wt % Li 2 O; 8 to 16 wt % Na 2 O; 0 to 3.5 wt % K 2 O 2 to 5 wt % MgO; 3 to 7.5 wt % CaO; 0 to 4.5 wt % SrO; and 0 to 1 wt % ZrO 2 , wherein the sum of Li 2 O, Na 2 O and K 2 O is from 11 to 18 wt %, and the sum of MgO, CaO and SrO is from 7 to 14 wt %.