| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a glass for chemical tempering that can reduce the frequency of replacement of molten salt.SOLUTION: A glass for chemical tempering contains, as represented by mole percentage based on the following oxides, SiOof 61-73%, AlOof 10.2-18%, MgO of 0-15%, CaO of 0-0.5%, ZrOof 0-4%, NaO of 11-16%, KO of 0-1% and BOof more than 0-5.6%, with SiO+AlOcontent of 65-85% and MgO+CaO content of 0-15%, and an R' value calculated by the following formula from contents of the respective components of 0.66 or more. R'=0.029×SiO+0.021×AlO+0.016×MgO-0.004×CaO+0.016×ZrO+0.029×NaO+0×KO+0.028×BO+0.012×SrO+0.026×BaO-2.002. The glass for chemical tempering has a thickness of 0.4-1.2 mm, and contains SO, chloride, and fluoride in amounts of 0.15% or less by mass%.</p> |
