| 摘要 |
A glass without lead or arsenic has good chemical characteristics of durability and stability against crystallization, a refractive index of 1.57-1.61, an Abbe number of 56-63 and a transformation temperature equal to or greater than 520[deg]C. Its composition (by wt %) is: SiO2 37 - 46; B2O3 12 - 18; Al2O3 1 - 7; LiO2 5.5 to less than 7; Na2O 1 - 5; K2O less than 4; MgO less than 7; BaO 21 - 29; SrO 0.1 - 1.5; ZnO 1 - 4.5; TiO2 0.1 - 0.5; and ZrO2 less than 0.7. The total amount of TiO2 and ZrO2 is less than 0.9.
|
