| 摘要 |
Coloured glass, which may be gray or bronze, comprises a base glass (which may comprise 68 to 75% SiO2, 10 to 18% Na2O, 5 to 15% CaO, 0 to 10% MgO, 0 to 5% Al2O3, and 0 to 5% K2O, where CaO + MgO is 6 to 15% and Na2O + K2O is 10 to 20%) and colourants comprising: 0.22 to 0.39 wt.% total iron as Fe2O3 wherein the ratio of FeO/total Fe as Fe2O3 is 0.35 to 0.64; 0.1 to 0.5 wt.% manganese compound as MnO2; 0 to 1.2 wt.% cerium oxide as CeO2; and 2 to 10 ppm selenium, and 0 to 20 ppm cobalt as cobalt oxide. The coloured glass has the following spectral properties at 4.0 mm. thickness: 65 to 78% light transmittance using Illuminant A (LTA) and using Illuminant C has a dominant wavelength of 493 to 577 nanometers with an excitation purity up to 7%. The infrared transmittance is 22-51% and the ultraviolet transmittance is 35-62%.
|
