Low liquidus glasses for television tube faceplates

Claim 1

A glass suitable for the faceplate of a television picture tube having a softening point between 685°-700° C., an annealing point between 495°-515° C., a strain point between 455°-475°, a coefficient of thermal expansion between 98-100×10 -7 /°C., a log resistivity at 250° C. greater than 9, a log resistivity at 350° C. greater than 7, a linear X-ray absorption coefficient at 0.6 A of at least 26 cm -1 , good resistance to X-ray and electron browning, and a liquidus temperature below 800° C. consisting essentially, in weight percent on the oxide basis as calculated from the batch, of: ______________________________________ SiO.sub.2 58-65 Al.sub.2 O.sub.3 1-3 CaO 1-4 SrO 6-12 BaO 2-9 PbO 1-3 Na.sub.2 O 5-9 K.sub.2 O 5-12 Na.sub.2 O + K.sub.2 O 14-18 TiO.sub.2 0.3-1 CeO.sub.2 0.05-0.5 ______________________________________ and being essentially free from MgO.