Patent ID: 6780803
Filing Date: 2004-08-24
Classification: C03C

Abstract:
An ultraviolet/infrared absorbent low transmittance glass consisting of base glass and colorants, said base glass comprising:65 to 80 wt. % SiO2; 0 to 5 wt. % Al2 O3; 0 to 10 wt. % MgO; 5 to 15 wt. % CaO wherein a total amount of MgO and CaO is between 5 and 15 wt. %; 10 to 18 wt. % Na2O; 0 to 5 wt. % K2O wherein a total amount of Na2O and K2O is 10 to 20 wt. %; and 0 to 5 wt. % B2O3; and said colorants comprising:1.2 to 2.2 wt. % total iron oxide (T-Fe2O3) expressed as Fe2O3; greater than 0.031 and not greater than 0.05 wt. % CoO; less than 0.0001 wt. % Se; and 0.11 to 0.2 wt. % NiO; and having a visible light transmittance (YA) measured by using the illuminant â€œAâ€  of not greater than 12% at 4 mm thickness, an excitation purity of not greater than 15% by the illuminant C in case that the glass has a thickness of 4 mm, a dominant wavelength between 480 and 525 nm by the illuminant C in case that the glass has a thickness of 4 mm, and bluish green shade or deep green shade.