Patent ID: 6103649
Filing Date: 2000-08-15
Classification: C03C

Abstract:
A glass composition, for use in forming a front panel of a cathode ray tube, having a linear X-ray absorption coefficient of at least 34 cm.sup.-1 at a wavelength of 0.6 .ANG., which comprises, based on the total oxides, 56.0 to 58.5 wt % of SiO.sub.2, 11.0 to 13.0 wt % of BaO, 7.5 to 9.0 wt % of SrO, 2.5 to 3.5 wt % of ZrO.sub.2, 1.0 to 2.5 wt % of ZnO, 0 to 0.5 wt % of Li.sub.2 O, 4 to 7.5 wt % of Na.sub.2 O, 7 to 11 wt % of K.sub.2 O, 1 to 2.5 wt % of Al.sub.2 O.sub.3, 0 to 0.2 wt % of MgO, 0 to 0.3 wt % of CaO, 0.3 to 0.5 wt % of TiO.sub.2, 0.2 to 0.5 wt % of CeO.sub.2, and 0.2 to 0.5 wt % of Sb.sub.2 O.sub.3 ; and satisfies the following formulae (1) to (3):0.58 .ltoreq.C.sub.BaO /(C.sub.BaO +C.sub.SrO).ltoreq.0.62 (1)4.5.ltoreq.C.sub.ZrO2 +C.sub.ZnO .ltoreq.6.0 (2)0.52.ltoreq.[C.sub.K2O /(C.sub.K2O +C.sub.Na2O)]-0.43C.sub.Li2O .ltoreq.0.58(3)wherein C.sub.BaO, C.sub.SrO, C.sub.ZrO2, C.sub.ZnO, C.sub.K2O, C.sub.Na2O and C.sub.Li2O represent the contents in % by weight of BaO, SrO, ZrO.sub.2, ZnO, K.sub.2 O, Na.sub.2 O and Li.sub.2 O, respectively.