Glass for chemical strengthening and chemically strengthened glass

A glass

• comprising, as expressed by mass percentage based on oxides:
• 60% to 75% of SiO2,
• 3% to 9% of Al2O3,
• 2% to 10% of MgO,
• 3% to 10% of CaO,
• 10% to 18% of Na2O,
• at most 4% of K2O,
• 0% to 3% of ZrO2,
• 0% to 0.3% of TiO2, and
• 0.02% to 0.4% of SO3;
• and
• having a temperature T2 at which a viscosity of a glass melt is 100 dPa·sec of 1530° C. or lower.

A glass for chemical strengthening

• comprising, as expressed by mass percentage based on oxides:
• 60% to 75% of SiO2,
• 3% to 9% of Al2O3,
• 2% to 10% of MgO,
• 3% to 10% of CaO,
• 10% to 18% of Na2O,
• at most 4% of K2O,
• 0% to 3% of ZrO2,
• 0% to 0.3% of TiO2, and
• 0.02% to 0.4% of SO3;
• and
• having a temperature T2 at which a viscosity of a glass melt is 100 dPa·sec of 1530° C. or lower.