Alkali-free glass

摘要: PURPOSE:To ensure superior acid and hydrofluoric resistances, meltability moldability by providing a compsn. consisting of specified amt., in total, amts. SiO2, Al2O3 B2O3, CaO, BaO, ZnO, TiO2 ZrO2 amt. or less MgO. CONSTITUTION:This alkali-free glass consists of, weight, 75-80%, 54-60% 10-15% 6-10% 8-15% 4-10% 1-6% 0.3-4% and/or 0-2% MgO contains practically no alkali metal oxide. Since this has heat, it is suitable for use as the material substrate on which thin oxide film formed patterned etching. This gives homogeneous product free from bubbles, striae foreign matter owing to its moldability.