Display cover glass and display cover glass fabrication method

Abstract

The present invention provides a cover glass for a display, having high durability to slow cracking and strong abraded strength even though a compressive stress is large and a depth of a compressive stress layer is deep. The present invention relates to a cover glass for a display, in which a depth of a compressive stress layer (DOL) is 30 μm or more, a surface compressive stress is 300 MPa or more, a position (HW) at which a compressive stress is half of a value of the surface compressive stress is a position of 8 μm or more from a glass surface, and the depth of the compressive stress layer (DOL) and the position (HW) at which the compressive stress is half of the value of the surface compressive stress satisfy the following formula: 0.05≦ HW/DOL ≦0.23  (1).

1 : A cover glass for a display, wherein
 a depth of a compressive stress layer is 30 μm or more,   a surface compressive stress CS is 300 MPa or more,   a position at which a compressive stress is half of the surface compressive stress is 8 μm or more from a glass surface,   the cover glass has a HW/DOL ratio of less than or equal to 0.23, and   the cover glass has a slow cracking height greater than a glass having the same CS×DOL value and a HW/DOL ratio of greater than 0.23.   
     
     
         2 - 6 . (canceled) 
     
     
         7 : The cover glass of  claim 1 , wherein the cover glass has a HW/DOL ratio of greater than or equal to 0.05 and a three-point bending strength higher than a glass having a HW/DOL ratio of less than 0.05. 
     
     
         8 : The cover glass of  claim 1 ,
 wherein the depth of the compressive stress layer DOL is 75 μm or less.   
     
     
         9 : The cover glass of  claim 1 ,
 wherein the cover glass has a thickness of 1.2 mm or less.   
     
     
         10 : The cover glass of  claim 1 ,
 wherein the cover glass has a composition of 50 to 80% of SiO 2 , 2 to 25% of Al 2 O 3 , 0 to 10%, of Li 2 O, 0 to 18% of Na 2 O, 0 to 10% of K 2 O, 0 to 15% of MgO, 0 to 5% of CaO and 0 to 5% of ZrO 2  in terms of mol %.   
     
     
         11 : The cover glass of  claim 1 ,
 wherein the cover glass has a composition of 50 to 74% of SiO 2 , 1 to 10% of Al 2 O 3 , 6 to 14% of Na 2 O, 3 to 11% of K 2 O, 2 to 15% of MgO, 0 to 6% of CaO and 0 to 5% of ZrO 2  in terms of mol %, and   wherein the total content of SiO 2  and Al 2 O 3  is 75% or less, the total content of Na 2 O and K 2 O is 12 to 25%, and the total content of MgO and CaO is 7 to 15%.   
     
     
         12 : The cover glass of  claim 1 ,
 wherein the cover glass has a composition of 68 to 80% of SiO 2 , 4 to 10% of Al 2 O 3 , 5 to 15% of Na 2 O, 0 to 1% of K 2 O, 4 to 15% of MgO and 0 to 1% of ZrO 2  in terms of mol %.