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