| 摘要 |
The present invention provides a chemically tempered glass capable of reducing the exchange frequency of a molten salt. Provided is the chemically strengthened glass containing, by molar percentage based on the following oxide, 61-73% of SiO_2, 10.2-18% of Al_2O_3, 0-15% of MgO, 0-0.5% of CaO, 0-4% of ZrO_2, 11-16% of Na_2O, 0-1% of K_2O, and 3.4-4.2% of B_2O_3, the sum of content of SiO_2 and Al_2O_3 being equal to or less than 85% and the sum of content of MgO and CaO being 0-15%, and R′ being calculated by the following formula is equal to or greater than 0.66 using the content of each component: R′ = 0.029×SiO_2 + 0.021×Al_2O_3 + 0.016×MgO - 0.004×CaO + 0.016×ZrO_2 + 0.029 × Na_2O + 0×K_2O + 0.028×B_2O_3 + 0.012×SrO + 0.026×BaO - 2.002. |
