Lead elution is little the funnel glass null for the cathode ray tube

摘要

PROBLEM TO BE SOLVED: To control the absorption coefficient of X rays above a specified value and to drastically reduce the lead elution by specifying the contents of PbO and Fe2O3. ;SOLUTION: This funnel glass for a cathode-ray tube contains, by weight, 10-30% PbO and 0.06-10% Fe2O3, and the absorption coefficient of the X rays of 0.6 Å wavelength is controlled to ≥40 cm-1. A glass contg. 48-58% SiO2, 0.5-6% A12O3, 10-30% PbO, 0-5% MgO, 1-6% CaO, 0-9% SrO, 0-9% BaO, 3-9% Na2O, 4-11% K2O, 0-1% Sb2O3 and 0.06-10% Fe2O3 is preferably used as such a glass. A high X-ray absorptivity is maintained without decreasing the PbO content. This glass is appropriate as the funnel glass for the envelope of a cathode-ray tube.;COPYRIGHT: (C)2000,JPO