| abstract |
The present invention relates to a glass for chemical strengthening, which is expressed in mole percentages based on oxides and contains 45 to 75% of SiO 2 , 1 to 30% of Al 2 O 3 , and 1 to 20% of Li 2 O, 0 Y 2 O 3 to 5%, ZrO 2 to 0 to 5%, and TiO 2 to 0 to 1%. The total of any one or more of MgO, CaO, SrO, BaO, and ZnO is 1 to 20%. Na 2 O And the total content of K 2 O is 0 to 10%, the total content of B 2 O 3 and P 2 O 5 is 0 to 10%, and the M value shown in the following formula is 1,000 or more. M = -5 × [SiO 2 ] + 121 × [Al 2 O 3 ] + 50 × [Li 2 O] －35 × [Na 2 O] + 32 × [K 2 O] + 85 × [MgO] + 54 × [CaO] － 41 × [SrO] －4 × [P 2 O 5 ] ＋ 218 × [Y 2 O 3 ] ＋ 436 × [ZrO 2 ] －1180 |