Patent ID: 6716780
Filing Date: 2004-04-06
Classification: C03C

Abstract:
A grey glass comprising:a base glass portion comprising: Ingredientwt. %Y2O30.10-2.0%SiO2â€‚â€‰67-75%Na2Oâ€‚â€‰10-20%CaOâ€ƒâ€‰5-15%MgOâ€ƒâ€‰0-5%Al2O3â€ƒâ€‰0-5%K2Oâ€ƒâ€‰0-5%BaOâ€ƒâ€‰0-1%and a colorant portion consisting essentially of: Ingredientwt. %total iron:0.10-0.90%erbium oxide:0.20-2.50%selenium:â€‚0.0-2.0%cobalt oxide:â€‚0.0-0.0050%titanium oxide:â€‚0.0-2.0%boron oxide:â€‚0.0-2.0%holmium oxide:0.05-1.60%thulium oxide:â€‚0.0-2.0%ytterbium oxide:â€‚0.0-3.0%lutetium oxide:â€‚0.0-1.0%wherein the grey glass has a dominant wavelength in the range of from 435 nm to 570 nm.