| 摘要 |
916,542. Optical glass compositions. BAUSCH & LOMB Inc. Aug. 17, 1961 [Sept. 30, 1960], No. 29713/61. Class 56. An ophthalmic glass composition consists essentially of the following ingredients in batch parts by weight, the preferred composition being given in brackets: Silica 65.3 to 67.3 (67.03); Alumina 0 to 1(0.50); potash 9.0 to 9.5 (9.45); soda 8.75 to 9.25 (8.95); zinc oxide 10 to 13 (10.88); ferric oxide 2.5 to 2.75 (2.63); nickel oxide 0.15 to 0.20 (0.185); cobaltous oxide 0.005 to 0.010 (0.0075); charcoal 0.05 to 0.10 (0.088); arsenous oxide 0 to 1.0 (0.50); antimony oxide 0 to 1.0 (0.75). The glass is a neutral gray colour and has a transmittance of about 31% at 2 mm. thickness.
|
