| 摘要 |
PROBLEM TO BE SOLVED: To provide a glass plate which allows sufficient improvement of the strength by chemical strengthening and suppresses occurrence of cracks with an indentation produced in use as chemically strengthened glass as a starting point.SOLUTION: A glass plate comprises, by mole percentage, 60-69% of SiO, 8-20% of AlO, 9-25% of NaO, 0-2% of KO, 0-14% of MgO, 0-2% of ZrO, 0-6% of BO, 0% or higher and lower than 1% of LiO and 0% or higher and lower than 1% of CaO, in a total SiO+AlOof contents of SiOand AlOof 80% or lower, a difference determined by subtracting the content of AlOfrom the content of NaO of lower than 5% and an X, calculated by using mole percentage contents of individual ingredients SiO, AlO, NaO and MgO, of 1.3 or smaller and a Z, calculated by using mole percentage contents of individual ingredients SiO, AlO, NaO, MgO, BOand KO, of 1,000 or greater (X and Z are defined in the specification). |
