Abstract: Glass compositions which are suitable for making face-plates of cathode-ray tubes used for displaying television pictures, particularly for displaying color television pictures. A problem in formulating such glasses is to obtain glasses which can be worked satisfactorily and which do not discolor significantly as a result of electron bombardment and X-ray irradiation. The glass compositions consist of the following constituents in the following quantities (expressed in % by weight):______________________________________ SiO.sub.2 57-65 ZrO.sub.2 1-4 Al.sub.2 O.sub.3 0-4 SrO 6-14 Na.sub.2 O 5.5-8.0 PbO 0-1 K.sub.2 O 7.5-10.0 Sb.sub.2 O.sub.3 + As.sub.2 O.sub.3 0-2 MgO 0-4 TiO.sub.2 0.2-2.0 CaO 0-4 CeO.sub.2 0.05-1.0 ______________________________________wherein wt. % Na.sub.2 O/(wt. % Na.sub.2 O+wt. % K.sub.2 O)=0.40-0.47 and wt. % BaO+2 wt. % SrO+2 wt. % ZrO.sub.2 +3 wt. % PbO>32.

Abstract: Disclosed is a cathode-ray tube having a face plate of soft glass which up to an accelerating voltage of 40 KV gives an X-ray emission of at most 0.5 mr/h measured at a distance of 5 cm. The glass has a strain point between 450.degree. and 480.degree. C. and a softening temperature between 660.degree. and 770.degree. C. and comprises, inter alia, 3-14% by weight of BaO and 5-10% by weight of PbO.