Patent ID: 6956000

Claim:
Panel glass, for a cathode ray tube, comprising: SiO 2 in an amount of from 45% to 60% by weight; Al 2 O 3 in an amount of from 0% to 1.2% by weight; MgO in an amount of from 0% to 3% by weight; CaO in an amount of from 0% to 3% by weight; SrO in an amount of from 7% to 15% by weight; BaO in an amount of from 6% to 14.5% by weight; ZnO in an amount of from 5% to 10% by weight; Na 2 O in an amount of from 0.01% to 4% by weight; K 2 O in an amount of from 6% to 15% by weight; Li 2 O in an amount of from 0.01% to 4% by weight; ZrO 2 in an amount of from 0% to 1.5% by weight; TiO 2 in an amount of from 0% to 3% by weight; CeO 2 in an amount of from 0% to 3% by weight; Sb 2 O 3 in an amount of from 0% to 2% by weight; and wherein SrO/(SrO+BaO) ratio by weight is from 0.35 to 0.70; wherein the glass is substantially free of PbO, wherein the glass has an X-ray absorption coefficient of 36.0 cm −1 or more at the wavelength of 0.6 angstrom, and wherein Na 2 O/R 2 O, K 2 O/R 2 O and Li 2 O/R 2 O (R 2 O: Na 2 O+K 2 O+Li 2 O) molar ratios fall within a range surrounded by the points A (0, 0.2, 0.8), B (0.2, 0.2, 0.6), C (0.4, 0.6, 0), D (0.2, 0.8, 0) and E (0, 0.4, 0.6) in the ternary phase diagram shown in FIG. 1 .